THE UNIVERSITY OF MICHIGAN COLLEGE OF ENGINEERING Department of Chemical and Metallurgical Engineering Final Report PROCESS VARIABLES IN GRAY AND DUCTILE IRON PRODUCTION FROM A BASIC CUPOLA R.- A. Flinn P. K. Trojan J. E. Brokloff D. L. Sponseller W. B. Pierce ORA Project 04599 under contract with: THE BUDD COMPANY DETROIT, MICHIGAN administered through: OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR April 1962

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PREFACE The authors express their appreciation to the Budd Company and in particular to Mr. Earl Morrison for monetary support of this investigation. The authors also wish to thank the following individuals who helped in the various experimental phases of this investigations: Messrs. D. Ashby, B. Avitzur, B. Bruss2 J. Judd, H. Kunsmann, C. Riva, F. Rote, G. Tuffnell, and M. Weins. iii

TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS vii SUMMARY ix I INTRODUCTION 1 A. Carbon 1 B Sulfur 2 IIo PROCEDURE 5 Ao Cupola and Auxiliary Equipment 5 Bo Charging Equipment 5 C. Metal Handling 6 Do Patching and Cupola repair 6 E Charges 6 F. Melting 7 G. Ductile and Duplex Irons 7 III. RESULTS AND DISCUSSION 9 A. Carburization and Carbon Control 9 1o Time after tap 9 2, Amount of coke in charge 9 3. Calcium carbide in charge 10 4. Design of cupola bottom 10 5. Type of metal charge (punchings vs. bales) 10 Bo Desulfurization 10 1. Slag composition-basicity and FeO content 11 2. Calcium carbide 11. 3. Slag depth 11 Co Important Operating Characteristics of the Basic Cupola 12 1. Charge materials 12 2. Dam and tap-hole relationships 12 3. Tap-hole procedure 12 4, Cupola well design 13 "uo Bed height 13 6o Operating ratios 13 D. Properties of Gray and Nodular Irons 14 io Microstructures 14 2o Test drums and spiders 15 35 Duplexed gray iron 15 v

TABLE OF CONTENTS (Concluded) Page IV. CONCLUSIONS AND RECOMMENDATIONS FOR FURTHER WORK 17 APPENDIX Io OPERATING DATA 5 APPENDIX II. SUMMARY OF CHEMICAL ANALYSES OF SLAG AND METAL 95 vi

LIST OF ILLUSTRATIONS Table Page I SUMMARY OF DATA FROM CUPOLA HEATS 18 II COMPARISON OF CUPOLA OPERATIONS 19 III SUMMARY OF NODULAR AND GRAY IRON PROPERTIES 20 IV DUPLEX-GRAY IRON (Heat No. 10) 21 Figure 1 Cross section of the Michigan Cupola. 22 2 Runner system of the Michigan Cupola. 23 3 Back-slagging arrangement 24 4 Plunging apparatus to treat 150 lb of metal, 25 5 Two varieties of sand bottoms used in the experimental runs. 26 6 Effect of slag analysis on desulfurization. 27 7 Location of a tensile specimen in a standard one-inch "Y" blocko 28 8 10OX; 5% nital l-DI; ferrite, spheroidal graphite (2% Nodulay 8-C). 29 9 10OX; 9 nital 3-D.; ferrite, spheroidal graphite, and flake graphite (3% Nodulay 8-C)o 29 10 LOOX; 5% nital 3-D2; ferrite, flake graphite (2-1/2% Nodulay 8-C). 29 1 1OOX; 5% nital 5-D1; ferrite, spheroidal graphite, pearlite (3% Nodulay 8-C). 29 12 OOX; 2% nital 5-D3; ferrite, spheroidal and flake graphite, pearlite, carbide (1% Nodulay 8-C). 30 vii

LIST OF ILLUSTRATIONS (Concluded) Figure Page 13 IOOX; 2%o nital 6-D1; ferrite, spheroidal graphite, pearlite (2-1/2% Nodulay 8-C). 30 14 1OOX; 2o nital 6-D2; ferrite, spheroidal graphite, pearlite (2% Nodulay 8-C)o 30 1 lIOOX; 2% nital 8-D2; ferrite, spheroidal graphite, pearlite (plunge 0o6% SIL-MAG-M). 30 16 lOOX; 2% nital 9-D1; ferrite, spheroidal graphite, pearlite (plunge 0o6% SIL-MAG-M). 31 17 OOX; 2% nital 2-G1; ferrite, flake graphite, pearlite (duplexed to induction furnace). 31 18 IOOX; 2% nital 5-G1i flake graphite, pearlite, carbide (duplexed to induction furnace). 31 19 1OOX; 2% nital 6-Dr-Cu; nodular brake drum, ferrite, spheroidal graphite, pearlite, carbide (2-1/2% Nodulay 8-C). 31 20 1OOX; 2% nital 7-Dr-Cu-l (nodular brake drum); ferrite, spheroidal graphite, pearlite, carbide (2-1/2% Nodulay 8-c). 32 21 1OOX; 2% nital 7-D.rCu-2 (flake brake drum); ferrite, flake graphite, pearlite, carbide (direct from forehearth) o 32 22 10OX; 2% nital 9-Sp-I (nodular truck spider); ferrite, spheroidal graphite, pearlite (plunging from induction furnace), 32 23 1OOX; 2%o nital 9-Sp-Cu (nodular truck spider); ferrite, spheroidal graphite, pearlite (plunging from cupola). 32 viii

SUMMARY It is often highly profitable to replace an acid-lined cupola with a basic-lined cupola because steel scrap ($25-$35/ton) can then be substituted in tne charge for higher priced pig iron ($55$60/ton). In addition, because of the refining action of the basic cupola, the resulting metal is very low in sulfur and can be used for either gray iron or nodular iron production, The purpose of this research is to investigate for The Budd Company the advantages and optimum conditions for melting in their new water-cooled basic cupola. By using the 30-ino-diam experimental cupola at Michigan, a large number of variables can be investigated in detail with accuracy, at low cost, and without disturbing production at the plant. This report summarizes the results of ten experimental heats. The data indicate the importance of many variables in optimizing operations, The chief commercial interest lies in the problems of carburization (which determines the amount of steel substituted for pig) and desulfurization (which determined the suitability of the metal for nodular iron production). The discussion takes up these points first, followed by consideration of general conditions for good cupola operation and a review of the properties of the gray and nodular irons which were produced. The data show the significance of coke ratio, type of steel charge, calcium carbide additions, and cupola design (at well and dam) for carburization. It is possible to use charges composed entirely of steel and foundry returns (no pig iron) Desulfurization is affected by slag basicity, slag voluwme, and cupola design. Values as low as.006% S were obtained. This represents the lowest sulfur level ever reported for cupola operation. The experiments provide a good deal of operating data concerning smooth basic cupola operation. The basic iron from the cupola can be inoculated either with f.errosilicon to produce a good grade of gray iron or with magnesium alloy to produce nodular iron of excellent properties, Reco.mmendations for future work are included. ix

I. I\NTRODUCTION In the foundry modernization program at The Budd Company, a basic cupola is'being used to replace the acid-lined cupola as a melting instrument,. This will enable the foundry to replace pig iron with less expensive steel scrap such as punchings, turnings, and bales. In addition, the basic cupola refines the metal, removing sulfur, and therefore provides excellent base metal for.the production of gray iron or nodu.lar iron for wheels and drums.'ihe purpose of' these experiments in the small (30-in.-diam) cupola at Mlichigan was to determine the principal variables of importance in the Budd operation. The same metal, coke, and flux materials were employed in pract;ica. 1 y all caseso Before discussing the actual experiments, a short review of the chemistry of the basic cupola may be helpful. The elements of principal concern are c.arbon, sulfur, phosphorus, silicon, and manganese. Since the work is directed principally at carbon and sulfur control, we will consider only these elements here. A. CARBON In practically all cupola operations, acid or basic, there is some gain in carbon as the liquid metal comes in contact with the incandescent coke. There is, however' a wide variation in the actual amount of carbon dissolved and it is this point which requires careful control. The driving force leading t;c solution of carbon can be shown by ithe followinrg da-ta for the maximum solubility of carbon in a 2% silicon cast iron at various temperatures' ~F Max 0 Carbon 2200 4- 0 24ao 4, 7 2600 652 In an acid-lined cupola the carbon dissolved from the coke is limited becaiuse the slag forms a pr+otective film over much of the coke surface. To attain a level of 36o c:arbon in brakedrums, for example, it is necessary to employ approximaitely iOto pig iron containing about 4K.2 carbon. By cont rast, in a basic-lined cupola the slag does not coat the coke and much higher carb on solution is obtained. For example, it is shown in the ody of Jthis report'that a cupola charge can be made up entirely of low-cost 1

steel scrap (65%) and normal foundry returns, gates, and risers (3%). This will have an average carbon content of 1.3%, but due to carburization in the cupola, it will produce liquid iron with 3.6-4.0% carbon as desired. This replacement of 40% pig iron in the charge with steel will result in a saving of $12.00 per ton of metal melted, assuming a cost differential of $50.00 per ton between pig iron and steel. To control this carbon solution to acceptaible limits is one of the objectives of this work, and this point will receive fuller attention in the discussion. B. SULFUR It is desirable to produce iron with minimum sulfur for two reasons. In gray iron sulfur increases chill depth leading to hard spots. This can be minimized by manganese additions. In nodular iron, sulfur must be removed before magnesium can be dissolved in the iron. If magnesium itself is used for this purpose, much heavier additions of inoculant are needed. Furthermore, the magnesium sulfide which is formed is a fertile source of cope surface inclusions. To reduce the sulfur content of the metal there are the following possibilities: (1) Lower the ingoing sulfur in metal charge, coke, and flux. (2) Maximize the amount of sulfur in the slag. By using steel (.03% average S) versus foundry pig iron (.12% average S), the ingoing sulfur is appreciably reduced. The coke usually contains X5-. 8% sulfur and therefore a low coke ratio is helpful in lowering the ingoing sulfur, The most important point in sulfur control, however, is the slag. To express the efficiency of a given slag in removing sulfur, the distribution ratio is used:.0 sulfur in slag Distribution ratio % sulfur in slag % sulfur in metal For example, a good basic slag would contain.20% S when the metal was.01o S, giving a ratio of 20:1. The factors which lead to good desulfurization are a high ratio of bases to acids in the slag as given by the molar rat io CaO + 2/3 MgO SiO2 + A1203 2

and a low iron oxide content. Bases such as CaO and MgO are important because the sulfur is then held more tenaciously by the slag, perhaps as calcium or magnesium sulfide. The low iron oxide is important because a high iron oxide favors the breakup of the otherwise stable sulfides and then the sulfur reverts of the metal. By contrast, in an acid cupola the iron oxide in the slag and low basicity give poor desulfurization ratios, of the order of 1:1 to 5:1. 3

IIo PROCEDURE Throughout these experiments, the 30-in. -diam basic cupola in the Cast Metals Laboratory at Michigan was used. It has been found that this cupola is the smallest unit which gives consistent, reproducible data which are representative of larger operations When cupolas of smaller diameters have been used, the large ratio of wall surface to cross-sectional areas results in unrepresentative data, a strong tendency for charge hangup in the stack, and other effects. The melting rate per square foot of hearth area, air and coke conslimpticn, and. other operating characteristics of the 30-in. cupola are representative of the commercial range. Many variables were studied in the course of this investigation; however, certain operating characteristics were maintained constant to establish a reference baseo Therefore the elements common to all heats will be discussed first after which the variables will be enumerated to outline the scope of the researcho A. CUPOLA AND AUXILIARY EQUIPMENT The cupola and runner are sketched in FigSo 1 and 2. The lining above the tuyeres is "Gundol" (double burned dolomite) while the well and runner lined with "High-Al-Ram-G" (high percent alumina and graphite). It should be noted that slag can be removed from both the front and back of the cupola as desired. Figure 3 is a detailed sketch of the back-slagging holeso A Roots-Connersville blower was used with the characteristics below (12.x, 42 ino ) Inlet volume: 2500 cfm Inlet pressure: 0 psig Discharge pressure ~ 1 psig Blower speed: 335 rpm Brake horsepcwer: 13.2 Th.e actual d.elivery volume of air was determined by measurement of the blower speed. Provision was also made for oxygen enrichment of the blast, although it was not used in this series of experiments. B. CHARGING EQUIPMENT The cupola was charged by a conical drop bottom bucket which was loaded and transported on the charging floor by a one-half ton electric hoist. The 5

charge bucket was 26-in. ID x 24 in. high with a 2-in. supporting flange 5 in. wide. A three-point support arrangement was used to hold the bucket in the cupola when the charge was dropped. C. METAL HANDLING Metal from the cupola ran directly into a 3000-lb forehearth lined with Shamva-Mullite. Most of the metal was then pigged into two sizes, 75 lb and 30 lb. The smaller pigs were used for the next heat to approximate the normal inplant scrap returns. Some metal was also withdrawn in hand ladles to supply the induction furnaces for duplexing and to provide metal for subsequent magnesium treatment. In the latter heats a runner extension was devised so that the forehearth could be bypassed and liquid metal could be run directly into a hand ladle. In this way metal at 2800 F could be tested in the nodular iron treatment, D. PATCHING AND CUPOLA REPAIR There was always a certain amount of burned out refractory which had to be replaced after each heat. In most instances hand patching was all that was necessary; however, a new layer of "Gundol" was blown in approximately every third heat. Below is a representative burn out for each heat based upon 1 to i-1/2-hr operation. Height Above Lip (doorsill), in. Thickness Lost, in. 12 (High-Al-Ram G) 1/4 Top of tuyeres (Gundol) 1-1/2 36 (Gundol) 1 48 (Gundol) 1/2 72 (Gundol) 0 to 1/4 After every heat the dam and slag notch in the runner were completely removed and replaced. E. CHARGES The charges, varied somewhat for each heat, are given in Appendix I. However, an effort was made to maintain a 65% steel charge with the balance scrap returns and lump 50% ferrosilicon. In this way the ingoing carbon and silicon were approximately 1.30 and 1.5%, respectively, for each heat except for the deviations noted in Appendix I. The scrap returns were pigs poured from the previous heat while the steel was automotive scrap from the Budd Co. approximating a good quality SAE 1008. 6

The total metallics in each charge was 400 lb while nonmetallics varied from 85 to 115 lb. Approximately seven charges were required to fill the cupola. The coke used was 3-1/2 x 4 in. of the following analysis: Coke Analysis, % Ash Analysis Free Carbon 91 SiO2 53.00 Volatile Matter 0.9 Fe203 4.70 Ash 7.6 A1203 35.65 Sulfur 0.5 CaO 2.10 MgO 1.47 S03 1.58 Inert 1.50 F,'MELT IN G Continuous performance plots for each heat are included in Appendix I and are fully discussed in the following section. For simplification, the tables of chemical analyses do not include Mn or P which ranged from 0.220.32 Mn and 0.012 to 0o028 P. G, DUCTILE AND DUPLEX IRONS In the production of nodular cast iron, two inoculation procedures were used, transfer and plunging. In the transfer technique the cupola metal was tapped on to Noduloy 8-C (46.1% Si, 9^6% Mg, 1.14% Ca, 0.64% Ce) after which it was transfered to a ladle containing late silicon as 85% ferrosilicon (aluminum bearing). Plunging was accomplished in a special deep ladle and plunging bell as shown in Figo 4. The ladle was lined with Shamva-Mullite and approximately 150 lb of metal were treated each time. For this quantity of metal,,88 lb of No. 2 Sil-Mag-M were used (61.6% Si, 3.6% Ca, 22,4% Mg, 150%o rare earths). The treated metal was then used to pour spiders, drums, wedge castings, chill wedges, microspecimens, etc,:Metal to be duplexed for gray iron was placed in a 60-lb capacity 50kw, 3000 cycle induction furnace. Steel, 50% ferrosilicon, and ferromanganese were then added for chemical control after which the metal was tapped with a late silicon addition as 85% ferrosilicon (aluminum bearing). More complete information is included in the next section, in Tables I, II, and II:I, and Appendix II.

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II, RESULTS AND DISCUSSION A short summrary of the data from the ten cupola heats are given in Table i. Using this,able and the individual heat sheets of Appendix I the data may bCe reviewed under t he following sectionsc A. Carburization and carbon control, 3, De su..fu.r i. z a': ion o. I:mportant operating characteris4tics of +the basic cupola, P. Prope rties of gray and nodular irons, A. AFib.:'t IZA.IOT' AND,,CAB-BO'N CONTR\OL Thse data of Table: ind:icates that it is possible to reach the desired level, of c.artin while using eonly steel and foundry returns in the cu.pola. The ratio of approximateely 65% steel, 35% returns was selected for this investigat ioin in view of present practice at the Budd Co but a still higher steel rat io can probably'be usedo The important variables affecting carbon content in' these tests are (.) time af-er tap, (2) amount of,coke in charge, (3) calcium carbide in. charge, (4) design, of.:-pola bottom, and (5) type of metal charge (bales vs. punchings), 1 -. Time Aft.er:Iapo "-here is a -trend toward higher carbon at'the beginning of the.heat'than a't:, for example, 20 miin after tapping, because the cuptia is not t~apped u.nt-:il a>bout?. 25 mmin after t-he'blast is turned on. Met al begins vto enter h se well. of the cia.pcla about 5 min aft-er the biast is on., T! has a Longer on., This early metal has a longer contact time with the coke and therefore shows greater arbLuriza:.ion:. Wh ile only a small amount of early:metal is involved, the carbon -culd e reduc.-ed by using a shorter time interval between blast: on and tap, 2, Arr >o:n:i of Coke i:..Charge, —In the last four. heats (7-1.0) the coke was reduced from:175'to j.5i of the metal. charge weight., This resu'lted in a genera.ll.y lower carbon level, particular.ly as the cupola approached steadystate operatio n It is true that other variables were changed at the same i.me, such as spar and lime, but the lower carbon is due to the combined effect of t.-se variables and is in linre wit-h observati ons of genera:l pract.ice, Besides economic reasorns, it, is ad.visable to strive for minimum coke level because of several effects, Excess coke reduces melt;i.rng rate since the extrna mai:er:ial. has toi be burned away before t-h.e metjal, higher in the stack 9

reaches the melting zone. Furthermore the sulfur and ash of the excess coke must be removed by the slag. The melting temperature was also adequate at the lower coke levels., Calcium Carbide in Charge. — In most cases 1.5% calcium carbide was used in the flux charge to promote basic, reducing conditions. Heat No. 7 vs. Heat No. 8, for example, shows that the carbon level is reduced when the carbide is removed, The use of calcium carbide in the cupola is receiving increased attention since the satisfactory development of a cheaper, lower melting point grade in West Germany. While the standard grade was used in these experiments, a sample of the new type should be tested. Design of Cupola Bottom. —In all heats except No. 9 the cupola botwom was inl the shape of a bowl as shown in Fig. 5. In Heat No. 9, the bottom was sloped upward in all directions from the tap hole at a pitch of 1. in./ft. in the latter case there was a much smaller bath of metal in con-'act with coke. This resulted in lower carbon content, At the 20-min mark, for example, the carbon was 3o37% in Heat No, 9 compared with 3.94% in Heat Noo 8. This technique provides, therefore, another method of carbon control, 5 T'ype of Metal Charge (Punchings vs. Bales) — Metal punchings (approximately L/4-in. thick) were used in all charges except No. 10 in which small bales were employed. From the preliminary data on this single heat, it+ appears that the bales result in lower carbon content. Even though the bale is madeup of light strips and sheets, it is a relatively large mass to heat and melt. The thermal. conductivity is much lower than in a solid piece of metal be.cause of the many spaces and the contact resistance of the surfaces. Beca;use of these effects, the center of the bale reaches the melting zone at a lower temperature than the punching, for example. As a result the carbon is somewhat lowered, Further experiments, varying the bale dimensions, should be helpful in assessing the effects of both briquettes and baleso B DESUJLFRIZATION Th:'e data of iTable I and the appendixes indicate that very low sulfur conte.nts (< 0o1% S) can be obtained consistently with modest amounts of limestone and otrier flux. This liquid metal is ideal for the production of duetile iron at minimum cost, A lower manganese level is suggested since for the stand.ard gray iron manganese is contained as manganese sulfide,'i7he variables affecting desulfurization will be discussed here under (1) slag composition- basicity and FeO content; (2) calcium carbide; and (3) slag d epth. 10

1. Slag Composition-Basicity and FeO Content. -In most discussions of desulfurizavti-o the basicity of the slag is considered to be a predomina-nt variable Actually the data of this report indicate that good desulfurization can be attai1ned with relatively low basicity provided the iron oxide content of the slag is low. An examination of Table I and Appendix II shows that in Heat Noso 1! 2, and 3 the basicity was comparable to that of later heats but the iro- c xid eas ev-er 2%. Thi s effect was produced by an air leak discussed in SFection C'. ITe com)rined effect of increased FeO and lowered basicity is se. er in Hiea- t No- 7 in which 1-i3 FeO and.8 basicity result in the highest ulfur cl vel cf t, e g rouLIp Heat Nos 5-10. Figure 6 is a complete plot of all C' aium Ca'a garbide - n all heats except NTo. 7, 6 lb of calcium carbide per charge a.s added.F This modest (1-1/2%) addition leads to higher carbon and lower suliur., Further work is needed to explore the effect of replacing the c alci-uLm caerbide with an equivalent amount of calcium in the form of limestonr e since the omission of the carbide led to a severe decrease in basicity ini Hea-t,o. 7 As seen from the log sheet for this heat, the basicity never excee - e 1 0 in the samples taken from the front of the cupola. 3" Siag Depth. —One of the interesting new developments in this research was the indication that the depth of slag inside the cupola may be important in controlling desulfurization. The variation in dam height and tap-hole dimensions may b;e summarized as follows: fia-, e'arm Heieht Aberoe Top of Tap-Hole Tap-Hole i 2 in. 1.5 in. diam, /4 1, in. diam 2- 1 x 2 sq ^ ~3 1l~ x 315 sq;4 ~ 1.5 x 755 sq 6-( 5 lo 5 x 355 sq i! 5 1 x5 x 3 5 sq 9 o5 x 3.5 sq (0 5 P5 x.5 x sq The Cde gre'e e..of desulfu7i;J.Tzation wh-ich was accomplished in the latter heats witn a oed'.+st flux charge may be the result of the high slag layer in the cupoia.. Oc asio al analyses we-re t;aken from the top of this layer (see Appen(1x. 1) a m-st i rost cases these were higher in FeO. This indicates that tne upper port iio-, o th slag layer can protect the lower region from oxidation and. th- r:ef'()rec produces better desulfurization. This point needs furt her ir v- s t i gat i n,, 11

C. IMPORTANT OPERATING CHARACTERISTICS OF THE BASIC CUPOLA In the course of the investigation a number of operating problems were successfully overcome. Since these problems may recur at the Budd Co., a discussion here may be helpful. These subjects, which are not necessarily interrelated, will be reviewed in the following order: (1) charge materials; (2) dam and tap-hole relationships; (3) tap-hole procedure; (4) cupola well design; (5) bed height; (6) operating ratios. I, Charge Materials.-To reach the desirable operating characteristics of the later heats, a number of changes in charge materials were necessary. The original source of fluorspar provided material which was at most 50% fluorspar (CaF2) mixed with limestone and other impurities, even galena (PbS). Some of the difficulties in the early heats in obtaining a fluid slag can be traced to this. In later heats a better grade of briquetted fluorspar (9410 CaF2, 6% inert organic bond) was employed satisfactorily. The dolomitic limestone of the earlier heats was replaced by a calcite limestone. The former appeared to breakdown into a powdery material after standing and this probably leads to greater losses during melting. Secondly, the higher percentage of calcium in the standard limestone should give higher desulfurizat ion, 2. Dam and Tap-Hole Relationships. —In the design of a front slagging spout, the critical dimension is the elevation of the lip of the dam in the runner above the top of the tap-hole. The liquid in this portion of the runner provides a seal which prevents the cupola gases from blowing through the tap-hole. In the past it has been customary merely to balance the pressure inside the cupola with a proper height of liquid metal outside the cupola. For example, with a cupola pressure 16 cz per sq in. (gage), a dam height of 4-in. would be used, (One cubic inch of liquid metal weighs approximately 1/4 lb; therefore 4 in of metal head outside the cupola would provide an equalizing pressure of 16 oz per sq in,) When a dam is designed under these conditions, relatively little slag is retained in the cupola, For example, if slag builds up inside the cupola, the pressure inside the cupola is the gas pressure plus that of the slag and therefore slag flows out until only the gas pressure remains to balance the metal head outside. In later heats the dam height was increased to 5 in. to allow for the development of a thicker slag layer inside the cupola. This investigation should be continued as it may be possible to reduce the flux charge considerably by more effective use of the slag. 3. Tap-Hole Procedure,~All the preceding discussion is predicated on the use of a tap-hole of very large dimensions so that it does not affect 12

the flow rate of metal and slag. In the later heats (4-10) this condition was attained by using a io -in.-high, 3,5-inr-wide pattern against which Hi AlRam G was rammed, After the pattern was removed, the lining was torch dried To make sure the full cross section of the hole would be operative during the heat, a careful botting procedure was employed. First a 3/8-in -thick layer of fresh ramming mix was applied to the outside of the holeo This was then backed with pure dry silica sand to within 3/8 in. of the inside of the holeo Then ramming mix was applied to seal the inside of the hole, When it was desired to tap -the cupola, the outer seal and then the sand were removed. Following this it was simple to knock through the inner seal and make cer'tain the entire hole was open. In the earlier heats in which a sma.aller tap-hole was used, it was difficult to clear the passage, and consequentr:ly a variable amount of metal and slag was retained in the cupola during ~the heat,.The tap-hole construction rather than the dam height controlled the level of:metal and led to retention of slag in the cupola. 4. Cupola Well Design. —In general the bowl type of design shown in Fig. 5 was employed. This was used from the beginning since maximum carburization was aimed for in the early heats. To indicate the effect of sloping the floor of the well so that much less metal was retained in the cupola another design was used in Heat No. 9. In'this case there was a straight pitch of I in,/ft toward the bottom of the tap-hole from all directions. This design led to lower carbon contents and slightly higher metal temperatures, as would be expected. In every e-ase the rammed sand bottom was covered with a 1/4-in, -thick layer of Gu.ndol, rammed in place as a dry mix, This was to prevent contamination of the slag by silica. Observation of the bottom sand after dropping the bottom showed +tha this procedure was successful since the Gundol had sin4,ered in place and no attack was evident, 5s Bed Height,- The bed height in the early heats, Nos. 1 and 2, of 56 in. was reduced to 18 in, in later heats because the slow initial melting rate indica-ted that the first few minutes were occupied in burning out excess coke before the metal could reach the melting zone, In the later heats 5% of the bed was madeup with calciu carbide. This resulted in good reducing and desulfurizing conditions in the early slag and was far more effective than merely placing a similar amount on top of the bed. 6, Operating Ratios —It is important to establish that the melting characteristics of a pilot cupola are close to those of the plant cupola with whic-:h i't is being compared Therefore, to use a common denominator the characterJisticns of the Michigan cupola are compared with several others in Table IT. It is difficult to have an exact duplication between cupolas due to the large number of variables, many of which have been pointed out in the previous 13

discussion. In fact, two cupolas in the same plant run under identical conditions can be expected to result in some variation in the normal operating ratios. The data of Table II indicate that the Michigan cupola compares favorably with the plant cupolas. Below are a few conclusions which explain the differences in operating characteristics. (a) More coke is required in a water-cooled cupola due to higher heat losses. (b) The presence of more stone requires more coke for melting. (c) A saving in coke can be appreciated by the addition of calcium carbide. (d) The required amount of limestone and fluorspar is less in a lined cupola due to erosion of the lining. D. PROPERTIES OF GRAY AND NODULAR IRONS Although the principal objective of the research was the investigation of cupola operations, some samples of gray and nodular iron were poured for examination. These interesting data have been divided into three sections: (1) microstructures; (2) test drums and spiders; and (3) duplexed gray iron. 1. Microstructures. —Microstructures and physical properties are summarized in Table IIli For nodular cast iron, tensile samples were taken from 1-in. "Y" blocks as shown in Figo 7. The tensile samples for the gray cast iron were obtained according to ASTM Specification (a48-60T). A few general trends are evident from an examination of the table: (a) The degree of nodularity is important to physical properties and often more indicative than the metal chemistry. (b) Flake graphite occurring after magnesium treatment has rounded lips and the material still possesses some elongation. (c) High sulfur irons present more difficulty with nodularity than metal lower in sulfur. (d) It is more difficult to control the magnesium recovery in the transfer technique than in plunging. (e) High residual magnesium in a low sulfur iron may result in poorer nodularity lk

(f) The presence of free carbide in nodular iron can still give elongat ions greater than 5% if ferrite is also present. These experiments should be continued with engineering evaluation of the relative performance of the many interesting and potentially useful new structures which were developed. 2. Test Drums and Spiders,-All the previous results about cupola operation and processing variations to the liquid metal must produce high quality castings. Therefore, as a check on casting quality and machinability of the final product, several castings were poured which were ultimately tested in the Budd Laboratories. Table III is a summary of the microstructures and hardnesses. The brake drums were poured in furfural molds from both nodular and gray iron. The hardnesses and the photomicrographs (Figs. 19-21) were taken from the thin inner flange of each drum where the chill problem would be most severe. Several conclusions are apparent from the microstructures and properties: (a) Castings were still machinable as cast even though some carbide was present. (b) Higher pouring temperatures resulted in less carbide. (c) The pouring temperature effect may be more pronounced in furfural molds as compared to green sand. (d) In the gray cast iron drum, under-cooled graphite was present close to the mold interfaceo Nodular cast iron truck spiders were also studied for characteristic properties. In this case green sand molds were used. Tensile samples were machined from the runners and were tested at the Budd Laboratories. The castings had predominantly pearlitic matrices and were machinable in the as-cast condition. The machinability was somewhat surprising as the carbon equivalent was lower than anticipated. As a final index of casting quality a nodular iron truck spider from Heat Noo 10 (not included in Table III) was tested in fatigue, The fatigue life was measurably greater than would be found in materials currently used for this application. The importance of pouring commerical castings can therefore be appreciated. However, before these findings can be fully utilized, more Budd castings should be poured from the cupola as this will be the normal melting instrument. 3. Duplexed Gray Iron. —In the final cupola heat, 50 lb of metal were duplexed to the induction furnace. The effects of holding time and postinoculant treatment were investigated. These data have been summarized in 15

Table IV. Chill samples of two types were taken from the induction furnace at regular intervals with either 85% FeSi or 65% CaSi used as a late addition. Since the silicon level was low for Heat No. 10, the more slowly cooled wedge chill provided better quantitative information. General conclusions are: (a) An increase in holding time increased the chill depth. (b) CaSi was a more effective post-inoculant than FeSi. (c) CaSi did a more effective job of removing the deleterious effects of increased holding time in the furnace. 16

IV. CONCLUSIONS AND RECOMMENDATIONS FOR FURTHER WORK The data of this portion of the investigation indicate that the original objective-substitution of steel scrap for pig iron-can be satisfactorily attained in the basic cupola. Many of the important details for conducting this operation have been indicated by the supporting data. These include factors in cupola design such as well, runner and tap-hole construction, flux calculations, metal-coke ratios, and so forth as discussed in the previous section. To optimize the basic operation at the Budd Co., it is important to explore the following variables in further detail in the experimental cupolas. 1. Minimum flux percentage for satisfactory operation. In the present work the flux was reduced during the later heats, but it is believed that further drastic reductions can be accomplished if they are accompanied by experimentation with dam height and runner design. In other words, the objective would be to accomplish greater refining per unit weight of flux by retaining a deeper slag layer in the cupola. 2. Further reduction of coke is possible and the exploration of metal temperature-coke ratio should be studied in more detail. 3. The conditions for minimum silicon and manganese loss should be explored. 4. The use of bales in place of punchings should receive further investigat ion to determine the role of bale size and its effect on stack pressure and analysis control. The use of briquetted borings should also be explored. 5, The experimental details of oxygen enrichment of the blast should be investigated since it may be possible to reduce carbon pickup and increase the temperature during start up of the cupola. 6. Since gray iron and ductile iron castings have somewhat different requirements for hot metal, the best operating practice for each should be clearly defined by experimentation, 7. An unusual series of microstructures was developed in test bars and castiings and these should receive further laboratory and field testing. 17

TABLE I SUMMARY OF DATA FROM CUPOLA HEATS Heat No. 1 2 4 5 6 7 8 9 10 Metal Charge o Returns (1) 30 33.5 34.5 34.4 1. 34.2 4.2 34.2 34.2 34.2 % Steel (2) 67 62 64 64 65 64 64 64 64 64 Carbon in 1.34 1.32 1.34 1.24 1.28 1.47 1.46 1.33 1.38 1.29 Silicon in.72.99.99 1.01 1.51 1.51 1.49 1.49 1.53 1.49 Returns 0.27.09.15.6.23.27.34.38.27 50% FeSi.72.72.90.86 1.45 1.28 1.22 1.1 1.1 1.22 Non-Metallics (% metal) Coke 17.5 17.0 17.2 17.2 17.6 17.1 14.6 14.6 14.6 14.6 Limestone (3) 5.0 4.8 6.1 7.4 7.6 7.3 4.4 4.4 4.4 4.4 Spar (4) 2.5 2.4 2.5 2.5 2.5 2.4 1.2 1.2 1.2 1.2 CaC2 1.5 1.4 1.5 1.5 1.5 1.5 0 1.5 1.5.5 CDr^ ~ Metal Characteristics co Maximum temperature 2750 2700 2700 2660 2825 2750 2730 2750 2780 2830 Carbon after: 10 min 3.80 3.90 3.40 3.99 4.24 -- 3.92 3.95 3.44 4.41 20 min 3.74 3.86 3.40 3.98 4.21 4.37 3.73 3.94 3.37 3.69 Sulfur after: 10 min 8.080.8.080.026.007 --.040.028.019.006 20 min.078.056.070.010.009.013.032.020.021.010 Minimum.077.047.037.010.007.009.029.017.016.006 Slag Characteristics Time (5) 23 19 60 6 15 12 9 5 6 18 FeO 3.45 4.5 2.2 1.7.9.95 2.25 3.1.55.9 Basicity.98 1.34.60 1.35 1.06 1.19.91.60 1.4 1.97 Maximum desulfurization ratio 2.7 12.0 15.1 60.0 100 63.0 23.4 49 37.2 81.0 (1) In early heats Sorel pig was used rather than actual returns. (2) All heats except No. 10 used punchings (No. 10 used bales). (3) The first three heats used dolomitic stone; the rest used a high calcium stone. (4) The first three heats used a 50% CaF2 spar; the rest used a 95% CaF2 spar. (5) Time was measured from tap until first slag.

TABLE II COMPARISON OF CUPOLA OPERATIONS International Ford Motor Budd Co. (1) Harvester (2) Co. () Michigan () I. Operating Data A. Ingoing Carbon 5.25 1.90 2.34 1.33 B. Outgoing Carbon 3.40-3.75 3.60-3.90 3.90 3.95 C. Metal Temperature 2800-2900 2700-2800 2700-2800 2650-2750 D. Air Temperature 600-725 Ambient Ambient Ambient II. Operating Data/Sq Ft/Min (lb) A. Melting Rate 22.3 20.9 16.6 14.8 B. Total Coke Wt 2.30 3.38 2.51 3.18 1. Coke wt for combustion 2.24-2.28 2.96-3.01 2.25 1.79 2. Coke wt for solution in iron 0.02-0.04 0.37-0.42 0.26 0.39 C. Stone Wt 0.75 1.64 1.48 0.65 D. Spar Wt 0 0.46 0.550.18 E. Carbide Wt 0 0 00.22 F. Air Wt 24.5-26.2 27.8 20.1 27.3 III. Operating Ratios A. Air Wt/Total Coke Wt 10.6 to 11.4:1 8.2:1 8.0:1 12.:1 B. Air Wt/Metal Wt 1.1 to 1.2:1 1.3:1 1.2:1 1.8:1 C. Metal Wt/Coke Wt for Combustion 9.8 to 10.0:1 7.0:1 7.4:1 8.3:1 D. Metal Wt/Total Coke Wt 9.7:1 6.2:1 6.6:1 6.8:1 E. Metal Wt/Non-Metallic Wt 29.7:1 10.0:1 8.2:1 14.1:1 1. Metal wt/stone wt 29.7:1 12.8:1 11.2:1 22.8:1 2. Metal wt/spar wt -- 45.2:1 30.0:1 81.8:1 5. Metal wt/carbide wt -- -- -- 28.2:1 F. Metal Wt/Slag Wt 2:1 12.0:1 8.:1 9.9:1 (1) Acid-lined; acid slag; cascade water-cooled. (A) Unlined; s lag; cascade water-cooled. q{:) U l bs sag; cascade wvater-cooaled.c ned; _asic slag; noncooled; Heat No. 3.

TABLE III SUMMARY OF NODULAR AND GRAY IRON PROPERTIES Analyses Physical Properties Z-nple ( 1) Figure (Pouring Temperature) C Si Mn S Mg _ Tensile Yield Eog. BH l-D1 8 2% Transfer (*) 3.69 1..21.057 69, 00 52,900 22 167 a (H.T.), S.G. 3-D1 9 5% Transfer (*) 5.30 1.8.21.070.032 (11) 47,500 52,00 15 125 a (H.T.), S.G., F.G. 53-2 10 2.5% Transfer (2560).3 1.61.21. 02.027 (11) 16,500 16,500 2 75 a (H.T.), F.G. 5-D1 11 35 Transfer (2400) 3.96 2.62.29.00o.04 (16) 68,000 5j,750 22 164, S.G., (P) 5-D3 12 1% Transfer (2370) 4.20 1.11.28.009.026 (27) 44,500 25,500 6 154 a, S.G., F.G., P, Ca 6-D1 15 2.53% Transfer (*) 3.85 1.88.29.008.080 (33) 58,000 7,2 146 a, S.G. (P) 6-D2 14 2% Transfer (2325) 3.96 1.76.27.006.050 (26) 58,250 56,500 20 146 C, S.G. (P) 8-D2 15.6% Plunge (2250) 3.97 1.83. 0.01 085 (65) 101,750 53,000 4 240 P, S.G., (a) FV 9-D1 16.6% Plunge (2400) 3.74 1.55.29.008 * 82,250 39,500 12 172 a, S.G., P 2-G1 17 Duplex Gray (2600) 3.29 1.47.25.051 - 17,000 - - 124 P, F.G. (a) 5-G1 18 Duplex Gray (2600) 3.76 1.38.89.010 - 7,000 - 2 143 P, F.G. (Ca) 6-Dr-Cu 19 Drum (Nodular) (*) 3.85 1.88.29.008 * * * * 176 a, P, S.G., Ca 7-Dr-Cu-l 20 Drum (Nodular) (2300) 3.63 2.22.27.010 * * * * 222, P, S.G., Ca 7-Dr-Cu-2 21 Drum (Gray) (2300) 3.57 1.83.73.040 - * * * 160 a, P, F.G. (Ca) 9-Sp-I 22 Spider (Induction) (2400) 3.72 1.42.33.007 * 83,900 (+) 44,800 (+) 4 (+) 205 (+) a,, S.G. 9-Sp-Cu 23 Spider (Cupola) (2400) 3.74 1.55.29.008 * * 48,100 (+) * 210 (+) a, P, S.G. * Data not taken (3) a ferrite + Data taken on runner system P pearlite (1) First digit refers to cupola heat number Ca Carbide (2) Transfer alloy was Noduloy 8-C S.G. speroidal graphite Plunging alloy was Sil-Mag-M-No. 2 F.G. flake graphite ( ) m:inor constituent I. T. heat-treated

TABLE IV DUPLEX-GRAY IRON (Heat No. 10) In preheated induction furnace at 6:01 p.m. All chills taken at 2750~F Comparison of 65% CaSi and 85% FeSi Time, Sample Wedge Chill T ime, Sample Taper Chill Chill Depth, Gray or Mottle Late Silicon p. m. No. _~_____ ___________in. Depth, in. 6:21 1 White 1.6 0.1 None 6:21 2 White 1.6 0.4 0.20 as FeSi 6:21 3 Slight mottle 1.6 0.8 0.20 as CaSi 6:36 4 Greater mottle 6:36 4N 1.3 0.8 0.40 as FeSi than No. 3 6:36 5 0.8 in. chill 1 2 0.40 as CaSi 6:51 6 Very little mottle 1.4 0.7 0.40 as FeSi 6:51 7 0.8 in. chill 1 2 0.40 as CaSi WEDGE CHILL e /41 1TAPER CHILL I-' Gray Gray or NOTE: Both chills Mo ttle 2" ore poured in i 3"M Chill | | core sand molds Depth ChillI Depth GRAPHITE BLOCK / 21

CHARGE DOOR ""J' LEVEL r1'./~ ft 12'TO DOOR SILL 41 35 WIND BOX GUNDOL (INSIDE - BACK- SLAGGINGSAND BOTTOMI 33SEE FIG.3 SEE FIG.5 ^^^ GUNDOL LATYERES Fi. 12' TiO DOO t Ct y^^ ^ ~.^~^~3.'~~ ~-WINDE ^ ^ GUNDOL~ LAY^ ER Fig. 1. Cross section of the Michigan Cupola.

NOTE: TAP HOLE 1-1/2"x3-1/2" UPWARD SLOPE APPROX.40 Imi R) WINDBOX ^ ^" ^~~~~~~~~~~~~~~~~DAM HEIGHT "X"' VARIED 2-6" TUYERE I/ SLAG NOTCH n, ~~~~~~~~~~2-1/2' Cl) ^ ///~- /^ Y" x4 1 3 c-f-8 f X+ I" X 1-1/2 r REFERENCE (TOP OF TAP N HOLE) 2T SO RSAND BOTTOM \- HI-AL-RAM "G"

I 1 TUYERE CENTERLINE _____________________ HI-AL-RAM "G" I" DIAMETER 8" NO.3 x, 2 I-1/4< NO. 2 3- 3 / - NO. 3-1/2 " TO BOTTOM SAND Fig. 3. Back-slagging arrangement.

WEIGHTS TO COUNTERACT BUOYANCY 3/4" STEEL ROD PROTECTION HOOD IMMERSION SLEEVE 2-7/8" O.D. x7/8"I.D 14" LONG 24" METAL \LEVEL 22"IMMERSION BELL~_ ~\ 22 REFRACTORY 8 SHAMVA- MULLITE CEMENT 10 i i "j | 2" LINING VAPOR ESCAPE PLUNGING LADLE HOLES \A 3"- I H 4-1/2" ^, ~10 " I00 Fig. 4. Plunging apparatus to treat 150 lb of metal. Alloy can is not in the bell. 2

CUPOLA. LEVEL LINE ~X^^^^7 TAP HOLE I-1/2 3-1/2" ^^^_.~^^ _^^ ^ ^^ITAPHOLE I -I/2"x 3-1/2" STRAIGHT PITCH SAND BOTTOM Fig. 5. Two varieties of sand bottoms used in the experimental runs. Note: Pitch as shown is the same in all directions toward the tap hole (bottom is covered with 1/4" Gundol). 26

RATIO (wt.% Sulfur)- Slag RATIO (wt% Sulfur )- Metal o 0-10 A 10-25 -/ * 25-50 A 50-100 Ratio Less Than 10 5.0 - 4.0- Ratio 10-25 Ratio 25-50 3.0 0 U2.0 2.0p > Ratio 50-100 z A O I ^ >Good Desulfurization with B - _ \ ^ Minimum Slag Volume 0.6 1.0 1.4 1.8 2.2 2.6 30 BASICITY MOLARecommended Range for SiO2 + A 1203 Fig. 6. Effect of slag analysis on desulfurization. 27

Reduced Sectimen ion a standard one-inch block. 2-1/4" Dia. "OO/ 4 -1/4" / ^~6" Fig. 7. Location of a tensile specimen in a standard one-inch "Y" block. 28

- - t,,,, -- S`C^ ~ @ t * * "'.^ ^'' ^.i o'' -".''' #4 B'* Q,''e-' t^ d a -- t o~.1 C. r.~-~ ^ - - -- ^ -:,:' ~ X *_* - * ^. <..,4. ~ $ -,..,._/ -/s,.-i3 -,-''".-> i..'-:, " 3'. *;'' - "' Vf.1~~ -,''.' - "- e - 0 -..-.-. Fig. 8. 100X; 5% nital l-Dl; ferrite, Fig. 9. 100X; 5% nital 5-D1; ferrite, spheroidal graphite (2% Noduloy 8-C). spheroidal graphite, and flake graphite (5% Noduloy 8-C). -se a - 2' e * 9 ^ " -.^W,. —!,,,,. r., i. Fig. 8. lOOX; 5% nital 1-D2; ferrite, Fig. 9. lOOX; 5% nital 5-D1; ferrite, spheroidal graphite (2% Noduloy 8-C). spheroidal graphite, and flake graphite Noduloy 8-C). - 4^^.W^ ^^p^^^^^ ^ -I" *V v I^'- 2Jf't r I^ tt- c\) -''' 1'I -4^ \.-. 0 -- i < "".f r;'- ^ c^ s i - - ^ - - i'.:, Fig. 10. lOOX; 5% nital 3-D2; ferrite, Fig. 11. iOOX; 5% nital 5-Di; ferrite, flake graphite (2-1/2% Noduloy 8-C). spheroidal graphite, pearlite (3% Nodu

r., ~.:0 $, t... ~ * *' *w * - r aI J7 ~1Y a - O C' 3t 4 e s... K 4 /* t' Y; * r 4 C' v'*!^ s'~ I:. I,k Fig. 12. lOOX; 2: nital 5-D; ferrite, Fig. 13. lOOX; 2 nital 6-D1; ferrite, spheroidal and flake graphite, pearl- spheroidal graphite, pearlite (2-1/2~ ite carbide (1 Noduloy 8-C). Noduloy 8-C). -AF t "- -.. * /.. d"...,. - I' *b~,~41J) (1 r~r QI e~o ~sars C1) 4 & L 4 s "' -' & Fig. 12. lOOX; 2% nital 6-D2; ferrite, Fig. 15. lOOX; 2% nital 6-Di; ferrite, spheroidal and flake graphittee, pearlrlite ( Nod- spheroidal graphite, pearlite (lu2-1/2%e ite, carbide (1% Noduloy 8-)C ). Nod 6 SIL-MAG-M). 3o *0, 1,, ~.l i 0 03.4 ~ Y;;c~L, 4,&A wek, Fig. l4. lOOX; 2% nital 6-D2; ferrite, Fig. 15.'OOX; 2% nital 8-D2; ferrite, spheroidal graphite, pearlite (2% Nod- spheroidal graphite, pearlite (plunge uloy 8-c). o.6% SIL-MAG-M). B _e~~~~~~~5

*^l' " 6 ii ^^.'.11: ~ 1 1^"'1^^ t q,r N4r rA ^ l —^ A ~ ~ * A~t'rtt~ ~~1dA~'"V'>I F'ig. 16. lOOX; 2% nital 9-D1; ferrite, Fig. 17. lOOX; 2% nital 2-Gi; ferrite,.6 SL-MAG-M). induction - furnace). C^~: ~' -' 6. 3 c st/.' *-. -L' - Fig. 18. 10OX; 2 nital 5-Gl, flake Fig. 19. 10X; 2% nital 6-Dr-Cu; noduspheroidal graphite, pearlite, carbide (duplungexed laker braphike drume ferrite, spheroidal to.VMt a to induction furnace), graphite, pearlite, carbide (2-1/2% W3 - B:-a^~" ^**/ <~8s~ -1^^: ~ -1 ^ ~ ^^^^ L 40*.-db*' *yLO^ i~::Z ~~ ~~~ h~.' ~~~~~~~~V ~~~~Igc:- ii ~-~7 il~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- ", Noduloy 8-C). r~

Fig. 20. IOOX; 2~ nita i 7-Dr-Cu-i Fig 21. q0 0 X; 2~ nital 7-Dr-Cu-2 ~4pr d ~Y1* fpr ^. ^^^ - ^ t-Waxvs~~tv4 %.'" Fig. 20. lOOX; 2% nital 7-Dr-Co-i Fig. 2. lOOX; 2% n ital ~-Dr-Cu-2 (oular brake sder); ferrite, sphe-' (flak brcke sder); ferrite, flk-e -1 i N duoy f-c). from f olar). *la tr0 sp ) f t Te 4 r43 i4t I"""'~x";o~~I *1 ij V A W.j a -t Fig. 22. lOOX; 2% nital 9-Sp-I Fig 25. lOOX; 2% nital 9-Sp-Cu (nod ulartrucrakesideru); ferritesphe- uflare truckeider); ferrite, spkeVibl:~~'~ ~L-~'P ** i ~4v V.4 l~(,i4~~:P~~ A zr'if~4 tL~~~~~~cd I~~~~~~~~a II~~~~~~ j~~~~~~~~~~~~~~~~4 VIM' i JWVl~a Z ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~iir~~~~~~~~~~~1 i ~3~ 1~ 1P ql.-9"? ~u? ~I ~ L1`4 fe,,'' ( t1 me I~~P' PA.?~n

APPENDIX I OPERATINO DATA

I I

HEAT NO. 1 1, Metallic s/Charge Sorel Pig 120 lb Steel Punchings 274 lb 50% FeSi 5.75 lb 75o Fe.Mn o60 lb 2, N onmet alli c s/ harge Coke 70 lb Stone (Dolomitic) 20 lb Spar (C%0 CaF2) 10.b'Ca.~C 6 lb 35 Bed a, Height 56 ino b, Nonmetallics 15 lb CaC2; 20 lb spar on top c. Burn in time 6-1/2 hr 4. Runner and Bottom a; Dam height, 2-3/4 in,'bo Tap-hole 1-1/2 in, diam Bo't;+om Depressed 1/2 ino below tap-hole; bowl shape 5. Analyses Samples ao Metal From forehearth b. Slag From slag notch 6, Comment s a, Probl.em in tapping Metal froze under dam b, Blast on until tap 12 min 35

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 31 in. (5.25 sq ft) 2. Temperature Range 2600-2740 F 3. Total Carbon, Ingoing 1.34% 4. Total Carbon, Outgoing (Range) 3.65-3.83% 5. Metal Melting Rate lb/min 84 lb/min 6. Nonmetallics (Exclusive of Bed)-Rate Coke 14.7 lb/min Stone 4.2 lb/min Spar 2.1 lb/min Carbide 1.25 lb/min 7. Air Weight 2250 cfm at STP 182 lb/min 8. Air Pressure 11 to 12 oz B. Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 16. 2. Total Coke wt/sq ft/min, lb-2.80 a. Coke wt/sq ft/min for combustion —2.37-240 bo Coke wt/sq ft/min for solution in iron —0.40-0.43 36

3. Nonmetallics/sq ft/min, lb Stone 0.80 Spar 0.40 Carbide 0.24 4. Air wt/sq ft/min, lb 34.7 C. Operating Ratios 1. Air vt/Total Coke wt 12G4. 1 2. Air wt/Metal wt 2.2 d1 3, True Coke Ratio-Metal wt/Coke wt for Combustion 6.68 to 6,75ol 4. Apparent Coke Ratio-Metal wt/Total Coke wt 5.72 1 5, Nornetallics-Total Metal wt/wt Stone + Spar + Carbide-11.1:1 a, Metal wt/Stone wt-20.0:1 b. Metal wt/Spar wt-400 0:1 C Metal wt/Carbide wt-67.2:1 6. Approximate Metal wt/Slag wt 8o25:1 37

^^~2500~ CUPOLA HEAT No. I z 2000 ILL 1500 3 w 1000 500 0 i i...... I I 1. 1 9:40 10:00 10:20 10:40 11:00 11:20 2800 - 2750 2700 LL w 2650 I-. ( 2600 Cc 0. % 2550 w 2500 2450 2400 2400 1 ~ I~ ~.~~I I I I I I l I 9:40 10:00 10:20 10:40 11:00 11:20 25 20 - E w n,s' 15 <4 I -.~,-') 10 9: 40 10:00 10:20 10:40 11:00 11:20 CLOCK TIME (AM) 38

CUPOLA HEAT NO. I.09 r:.08 D:: LL. _J.07 en w.06 0 w t:.J..05 - _. — v —----- 9:40 10:00 10:20 10:40 11:00 11:20 4.6 z 4.4 m > 4.2 w $ 3.8 0 3.6.!.'I I,, I i i I 34 9:40 100 0:00 10:0:40 11:00 11:20 4.2 V z o 4.0 O 3.8 U 3.6 k, II ~: oO CLOCK TIME (AM) 539 39

CUPOLA HEAT NO. I 5.0 4.0 10:56 ~..,....:00 3.00 o o 0 0: 2.0 - cL LJ 0 I I I I I I I I II I I 1 0.6 1.0 1.4 1.8 2.2 2.6 30 Co O + 2/3 M gO MOLAR RATIO C 24 SiO2 + AI203 ho

HEAT NO. 2 1. Metallic s/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50% FeSi 6 lb 75% FeMn 13 lb 2. Nonmetallics/Charge Coke 70 lb Stone (Dolomitic) 20 lb Spar (50% CaF2) 10 lb CaC2 6 lb 3, Bed a, Height 56 in, b. Nonmetallics 50 lb stone, 20 lb spar, 15 lb CaC2 on top c. Burn in time 3 hr 4. Runner and Bottom a. Dam height 2-3/4 in. b, Tap-hole 1-1/2 in. diam c. Bottom Depressed 1/2 in. below tap-hole; bowl shape,5 Chemical Analyses Samples a. Met al From forehearth b. Slag From front slag notch 6. Comment s a, Breast became hot b, Blast on until tap-16 min 41l

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 31 in. (5.25 sq ft) 2. Temperature Range 2600-2700 F 3. Total Carbon, Ingoing o132% 4. Total Carbon, Outgoing (Range) 3.62-3091 5 Metal Melting Rate lb/min 62 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 10.3 lb/min Stone 2.95 lb/min Spar 1.47 lb/min Carbide 0.89 lb/min 7. Air Weight 2000 cfm at STP 162 lb/min 8. Air Pressure 10 oz B, Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 11.8 2. Total Coke wt/sq ft/min, lb —196 ao Coke wt/sq ft/min for combustion-162-1.67 b, Coke wt/sq ft/min for solution in iron —0.29-0.34 h2

3o Nonmetallics/sq ft/min, lb Stone o.56 Spar 028 Carbide 0.17 4, Air wt/sq ft/min, lb 31.0 C. Operating Ratios 1o Air wt/Total Coke wt 15o8 1 2, Air wt/Metal wt 2.6:1. 3. True Coke Ratio-Metal wt/Coke wt for Combustion 7.1 to 7.3:1 4. Apparent Coke Ratio-Metal wt/Total Coke wt 6.03.1 5. Nonmetallics —Total Metal wt/wt Stone + Spar + Carbide-11.7:1 a. Metal wt/Stone wt-21.1:1 bo Metal wt/Spar wt-42 2:1 c. Metal wt/Carbide wt-69.5:l 6. Approximate Metal wt/Slag wt 8.5:1 43

CUPOLA HEAT NO. 2 2500Z 2000 UL 1500 w 1000 - 500 0 0 i I, I I Il 1 I 4:00 4:20 4:40 5:00 5:20 5:40 2800 2750 2700 LL. 2650 2600 2 2550 2500 2450 2400 I i 4:00 4:20 4:40 5:00 5:20 5:40 2520 0 / 20 0 - 0 I L 5 4:00 4:20 4:40 5:00 5:20 5:40 CLOCK TIME (PM) 44

CUPOLA HEAT No.2.07.06 - i. -.05 LUJ w.03 - 0F' l I I ~I I I... I I 4:00 4:20 4:40 5:00 5:20 5:40 4.6 z 4.4 w < 4.2 z 0 cr 3.8 o 3.6 3.4 i 1 4:00 4:20 4:40 5:00 5:20 5:40 4.2 z o 4.0 m 3.8 z (J 3.6 o Q 3.4 m C 3.2 4:00 4:20 4!40 5:00 5:20 5:40 CLOCK TIME (PM)

CUPOLA HEAT No.2 5.0 4:50 5:10 4.0 0 3.0 U. z w 0 0: 2.0 - i. 1.0 0.6 1.0 1.4 1.8 2.2 2.6 3 0.6 1.0 1.4 1.8 2.2 2.6 30 CoO +2/3MgO MOLAR RATIO SoO+2/3MgO SiO2 + AIE03 46

HEAT NO. 3 1. Metallics/Charge Scrap Returns 100 lb Sorel Pig 40 lb Steel Punchings 260 lb O0% FeSi 7.25 lb 2. Nonmetallics/Charge Coke 70 lb Stone (Dolomitic) 25 lb Spar (50% CaFE) 10 lb CaC2 6 lb 3. Bed a, Height 48 in. (thought to be incorrectly measured) b. Nonmetallics 50 lb stone, 20 lb spar, 15 lb CaC2 on top c. Burn in time 5-1/2 hr 4, Runner and Bottom a. Dam height 2 in, b, Tap-hole lin. x 2 ino (rectangular) c. Bottom Depressed 1/2 in. below tap-hole; bowl shape 5. Chemical Analyses Samples a, Metal From forehearth b. Slag From front and back slaggers 6 ~ Comiment s a, Breast was blowing b, Spar was a poor grade c. Bed was low d. Blast on until tap —6 min 47

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 31 in. (5.25 sq ft) 2. Temperature Range 2600-2700 F 3. Total Carbon, Ingoing 1.34% 4, Total Carbon, Outgoing 3545% 5 Metal Melting Rate lb/min 65 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 11,1 lb/min Stone 3.98 lb/min Spar 1.60 lb/min Carbide 0.96 lb/min 7. Air Weight (Average) 1650 cfm at STP 133 lb/min 8. Air Pressure 6 to 10 oz B. Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 12.4 2. Total Coke wt/sq ft/min, lb —211 a. Coke wt/sq ft/min for combustion-1.83 b. Coke wt/sq ft/min for solution in iron —0.28 hQ

3. Nonmetallics/sq ft/min, lb Stone 0076 Spar 0031 Carbide 0.18 4. Air wt/sq ft/min, lb 25.4 C, Operating Ratios 1, Air wt/Tootal Coke wt 12.0 1 2. Air wt/Metal wt 2, 05 35 True Coke Ratio-Metal wt/Coke wt for Combustion 68 Al Ce 4. Apparent Coke Ratio —Metal ^,/Total Coke we 5o91. 5. Nonmetallics-Metal wt/wt Stone + Spar + Carbide-909ol a, Metal wt/stone wt —l16 3o: b, Metal wt;/spar wt-40o,0:1 C, Metal wt/carbide wt —69. 0:1 65o Approximate Metal w,/Slag wt. 7. 0 5 49 1

CUPOLA HEAT NO. 3 2500 Z 2000 L. 1500 I 1000 -J 500 C) 1:00 1:20 1:40 2:00 2:20 2:40 3:00 2750 2700 L. o 2650 W I 2600 c1 ~a 2550 2500 2450 2400 i ii i 1:00 1:20 1:40 2:00 2:20 2:40 3:00 25 20 N 0;, -- Do a. 5 1, 1:00 1:20 1:40 2:00 2:20 2:40 3:00 CLOCK TIME (PM) 50

CUPOLA HEAT No.3.08.07.06.04 -J >4.6 3 04 w.0 0 ii z 4.0:00 1:20 1:40 2:00 2:20 2-40 3:00 4.2 o4.0 Iz 4., 3.8 - 0 cc L ON o 3 _ o C 3.4 - m I 3I2 L I I I I I I 1:00 1:20 1:40 2:00 2:20 2:40 3:00 CLOCK TIME (PM) I~~u =~~ ~

(#3) (#3) CUPOLA HEAT NO. 3 2:46 2:28 7.0 -0 —o (Back) 6.0 See Fig. 3 for Location oS5.- of Back Slag u. L&J z m 4.0 w IJ 0. 3.0 2:17 2.0 2:25 (Front) 1.0 0.6 1.0 1.4 1.8 2.2 2.6 30 CoO + 2/3 MgO MOLAR RATIO +2 SiO2 + A1203 52

HEAT NO. 4 1. Metallics/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50T FeSi 7 lb 2. Nonmetallic s/Charge Coke 70 lb Stone (Non-dolomitic) 30 lb Spar (95% CaF2) 10 lb CaC2 6 lb 3. Bed a. Height 48 in. b, Nonmetallics 50 lb stone, 20 lb spar, 15 lb CaC2 on top c. Burn in time 3-1/2 hr 4. Runner and Bottom a, Dam height 3 in. b. Tap-hole 1 in. x 2 in. (rectangular) c. Bottom Depressed 1/2 in. below tap-hole; bowl shape 5. Chemical Analyses Samples a. Metal From forehearth and pigs b. Slag From front slagger 6. Comment s a, Hi-A1 Ram G refractory was of a poor grade and caused difficulty with ramming breasto b. Metal ran into windbox through breast-short run co Blast on until tap-24 min Data incomplete due to metal run out into windbox. 55

CUPOLA HEAT N0.4 2500 Q 0-0 _' XI 1 2000 " 1500 w 1000 - 500 0 U 2650 0 2600: 2550 0J 2 2500 I2450 2400 500 ^5:00 5:20 5:40 6.00 6:20 6:40 25 - 20 0 oo wr 8 a. II- _ - - 05:00 5:20 5:40 6.00 6:20 6:40 CLOCK TIME (PM) 54

CUPOLA HEAT No.4.04 U..03, \.02 z o J w.01 Lw bJ a. 0O I I I. I I I I I I 5'00 5:20 5:40 6:00 6:20 6:40 4.8 - 4.6 a 4.4 _ 4.2 _ 0o z 0 w 4.20 0 3.8 3.6 1, l l I ll 5:00 5:20 5:40 6:00 6:20 6:40 4.6 4.4 z o 4.2 Co 4Q o 4.0_ z o 3.8 w -. 3.6 CIL):l I 3.4_ - 0 3.2 I 1 1 5:00 5:20 5:40 6:00 6!20 6:40 CLOCK TIME (PM) 55

CUPOLA HEAT NO.4 3.0 so 0 IL i 2.0 5 z 5:50.I. 1.0 - 6'08 IJ 0.6 1.0 1.4 1.8 2.2 2.6 30 MOLAR RATIO CO+2/3 SiO2 + A1203 56

HEAT NO. 5 lo Met allics/Charge Scrap Returns 50 lb Sorel Pig 75 lb Steel Punchings 260 lb 50%o FeSi llo5 lb 2. NorLmetallics/ Charge Coke 70 lb Stone (High Ca) 30 lb Spar (950% CaF2) 10 lb CaC2 6 lb 35 Bed a. Height 48 in, b. Nonmetallics 60 lb stone, 20 lb spar, 20 lb CaC2 on top Co Burn in time 2-1/2 hr 4. Runner and Bottom a, Dam height 4 in. b. Tap-hole 1-1/2 in, x 3-1/2 in, (rectangular) co Bottom Depressed 1/2 in. below tap-hole; bowl shape 5, Chemic'al Analyses Samples a, Metal Runner and forehearth b o Slag Front and back slaggers 6 C"omnment s a, Windbox cut away at the breast to facilitate ramming'b Blast on until tap-23 min c, Difficulty with tapping-cupola off 12 min 57

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 33 in. (5.94 sq ft) 2. Temperature Range 2600-2800 F 3. Total Carbon, Ingoing 1.28% 4. Total Carbon, Outgoing 4.20-4.24 5. Metal Melting Rate 93 lb/min 6o Nonmetallics Rate (Exclusive of Bed) Coke 16 6 lb/min Stone 7.1 lb/min Spar 2.37 lb/min Carbide 1.42 lb/min 7. Air Weight (Average) 2050 cfm at STP 166 lb/min 8. Air Pressure 14-19 oz B. Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 15.6 2. Total Coke wt/sq ft/min, lb-2.80 a. Coke wt/sq ft/min for combustion-2.34 b. Coke wt/sq ft/min for solution in iron —O. 46

3. Nonmetallics/sq ft/min, lb Stone 1,20 Spar 0 40 Carbide 0. 2 4. Air Weight/sq ft/min, lb 28.0 C, Operating Ratios I, Air wt/'T-Lotal. Coke wt 10. 0 1 2. Air wt/Metal wt 1,.8:l 3. True Coke Ratio-Metal wt/Coke wt for Combustion 6 7:1 4, Apparent Coke Ratio-Metal wt/Total Coke wt 5.6:1 5. Nonmetallics-Total Metal wt/wt Stone + Spar + Carbide —8o:l a. Metal wt/stone wt —13o 0:1 b, Metal wt/spar wt —39039 1 c. Metal wt/carbide wt-65o 0:l 6 Approximate Metal wt/Slag wt 6 6 1. 59

CUPOLA HEAT No. 5 2500 Z 2000 I uL 1500 w 1000 o 500 0 4:20 4:40 5:00 5:20 5:40 6:00 6:20 2850 2800 0:: 2750: 2700 w w 2650 2600 2550 2500 1i 4:20 4:40 5:00 5:20 5:40 6:00 6:20 25? 20- o 0 o0 Iso C I.15C') u,) 10 0 a.= 0 ___ I I~.0~1~\~1~1 4:20 4:40 5:00 5:20 5:40 6:00 6:20 CLOCK TIME (PM) 6o

CUPOLA HEAT No.5.04..3 LL n.02 - Iz J.01 - r O w Q.. 4:20 4:40 5:00 5:20 5:40 6:00 6:20 4.8 - 4.6 z.. 4.4 O_ S 4.2 z 0 m 4.0 cr 3.8 3.6 I I I 4:20 4:40 5:00 5:20 5:40 6:00 6:20 4.6 4.4 z o 4.2 o Qc I4.0 z 3.8 a. O 3.6 - o OClA.~- - 3.4- - 3.2tlf IA 3.2 4:20 4:40 5:00 5:20 5:40 6:00 6:20 CLOCK TIME (PM) 61

CUPOLA HEAT No.5 3.0 0-5:53 (*3) Back 0 o See Fig.3 for Location L. 2.0 of Back Slag z w Cr w LJ - 1.0 5:30 0t] t zz~C o52: ~5:40 - - 5'43 5:34 O I I I I I I., I I 0.6 1.0 1.4 1.8 2.2 2.6 30 ML A ATI CoO + 2/3 MgO MOLAR RATIO C 2/3M 5iO2 + A1 203 62

HEAT NO. 6 1o Metallic s/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50% FeSi 1.0o5 lb 2, Nonmetallic s/Charge Coke 70 lb Stone (High Ca) 30 lb Spar (95% CaF2) 10 lb Cal(2 6 lb 3, Bed a, Heighht 48 in, b. Nonmetallics 60 lb stone, 20 lb spar, 20 lb CaC2 on top c. Burn in time 4 hr 4, Runner an-d BEottom a, Dam height 4 in, b. Tap-hole 1-1/2 in, x 3-1/2 ino (rectangu.lar) co Bottom Depressed 1/2 ino below tap-hole; bowl shape 5 ChLermic. al Ana lyses Samples a. Metal Runner, forehearth, and pig molds c. Slag Front and back slaggers 6. Comments a. Metal Kished'o Blast on until tap —21 min

A, Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 33 in. (5.94 sq ft) 2. Temperature Range 2600-2750 F 3. Total Carbon, Ingoing 1.47% 4. Total Carbon, Outgoing 4. o8-4.36 5. Metal Melting Rate lb/min 80 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 13.6 lb/min Stone 5.8 lb/min Spar 1.94 lb/min Carbide 1.17 lb/min 7. Air Weight (Average) 2050 cfm at STP 166 lb/min 8. Air Pressure 12-19 oz B. Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 1304 2. Total Coke wt/sq ft/min, Lb-2o29 a. Coke wt/sq ft/min for combustion-1.90-1094 b Coke wt/sq ft/min for solution in iron —0.35-039 64

Nonmetallics/sq ft/min, lb Stone 0098 Spar 0.33 Carbide 0.20 4. Air wt/sq ft/min, lb 28.0 C. Operating Ratios 1. Air w-t/Total Coke wt 12.,2:1 2. Air wt/Metal wt 2.-09:1. True Coke Ratio-Metal wt/Coke wt for Combustion 6.9 to 7.11l 4. Apparent Coke Ratio~Metal wt/Total Coke wt 5 85:1 N onmetallidcs-Total Metal wt/wt Stone + Spar + Carbide-8o9:. a, Metal wt/stone wt-130 7 1l b o Metal wt/spar wrt40066: co Metal wt/carbide w+t-670 01 6. Approximate Metal -wt/Slag wt 6o9 1

~~2500 ~CUPOLA HEAT No.6 2500 LL 1500 O' I000 - 500 I t I I I I I I I I I I I 0 ~ 5:00 5:20 5:40 6.00 6:20 6:40 7:00 2800 2750 2700, 2650 2600 - 2550 2500 2450 - 2400 I I I I I 5:00 5:20 5:40 6.00 6:20 6:40 7:00 2520 Nr CL DI,) 10 o C, I l l l I,,. 0. 0: _o 5:00 5:20 5:40 6.00 6:20 6:40 7:00 CLOCK TIME (PM) 66

CUPOLA HEAT N0.6.04 u.03 cn.02 z cr.01 w a. 0 5:00 5:20 5:40 6.00 6 20 6:40 4.8 4.6 4.4 4.2 z 0,4 4.0 Q 3.8 3.6 5:00 5:20 5:40 6.00 6:20 6:40 4.6 4.4 z o 4.2 z 0 3.8 _ L 1 O a0. 3.6 o O o 3.4 5:00 5:20 5:40 6.00 6:20 6:40 CLOCK TIME (PM) 67

CUPOLA HEAT No. 6 5.0 0-6:06 (*3) Back See Fig 3 for Location of Back Slog 0 z 3.0Lc 0 0. $ 2.0 Ed 3:~^~ _-~~ ~~55:53 1.0 5 5:43 5:30 01,I, I1, I I I I_ I I 0.6 1.0 1.4 1.8 2.2 2.6 30 MOLAR RATIO Co+2/3MgO SiO8 +A 203 68

HEAT NO. 7 1o Mietallics/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50% FeSi 10 lb 2, Non.metall ic s/Charge Coke 60 lb Stoone (High Ca) 18 lb Spar (95% CaF2) 5 lb 3 Bed a. He ight 48 in, b. Nonmetallics 45 lb stone, 15 lb spar, 15 lb CaC2 on top ce Burn in time 6-1/2 hr 4. Runner and Bottom a. Dam height 5 ino b o Tap-hole 1-1/2 in, x 3-1/2 in, (rectangular) c, Bottom Depressed 1/2 in. below tap-hole; bowl shape 5. Chiemical Analyses Samples a. Me;tal. Forehearth and pig molds b. Slag Front and back slaggers 6o Comments a. Metal came out of front slagger while slag was still in the cupola'b. Blast on until tap-22 min 69

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 34 in. (6.3 sq ft) 2. Temperature Range 2600-2750 F 3. Total Carbon, Ingoing 1.46% 4. Total Carbon, Outgoing 3.70-4.05 5. Metal Melting Rate 86 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 12.5 lb/min Stone 3.76 lb/min Spar 1.05 lb/min Carbide None 7. Air Weight (Average) 21.75 cfm at STP 176 lb/min 8. Air Pressure 14-18 oz B. Operating Data/Sq Ft/Min lo Melting Rate/sq ft/min, lb 13.6 2. Total Coke wt/sq ft/min, lb —lo99 a. Coke wt/sq ft/min for combustion —164-l168 bo Coke wt/sq ft/min for solution in iron —0.31-0o35 70

3. Nonmetallics/sq ft/min, lb Stone 0.60 Spar 0.17 4. Air wt/sq ft/min, lb 28.0 C. Operating Ratios 1. Air wt/Total Coke wt 14.1:1 2. Air wt/Metal t 2 06 1 3 Tr-ue Coke Ratio-Metal wt/Coke wt for Combustion 8.1 to 8~3:1 4. Apparent Coke Ratio-Metal wt/Total Coke wt 6.85.:1 5 Nonmetallics-Total Metal wt/wt Stone + Spar-17 7:1 a. Metal wt/stone wt-22 7:1 b, Metal wt/spar wt.-80,0:1 6, Approximate Metal wt/Slag wt 1o6:1 71

CUPOLA HEAT NO. 7 2500 Z 2000 ILL 1500 o w 1000 500 0 50 5:00 5:20 5:40 6.00 6:20 6:40 7:00 2800 2750 LL.:500 w 2700 r 2650 a. S 2600 2550 2500 ~ 5:00 5:20 5:40 6.00 6:20 6:40 7:00 25 20 20 N 0, 150-,.,n lo 4 w 0! I I, 5:00 5:20 5:40 6.00 6:20 6:40 7:00 CLOCK TIME (PM) 72

CUPOLA HEAT No.7.04 23.03 UJ Cn H.02 z ci.01 0! I 5:00 5:20 5:40 6.00 6:20 6:40 7:00 4.8 H 4.6 z -j < 4.4 \ 3 w 4.2 z 0 4.0 - 0 3.6 5:00 5:20 5:40 6.00 6:20 6:40 7:00 4.6 4.4 - z o 4.2 Q O 4.0 - z uJL 34 o.. cL I I 73

CUPOLA HEAT NO. 7 3.0 Front o 5:49 See Fig.3 for Location U. of Back Slag 2.0 5:53 6-14 (#2) 5:57:21 (#2 B:^00 U - _ Back I. / 5 I c 06:02 ~ I.o- (/6 #21(#2) o 6:25 (*3) 0.6 1.0 1.4 1.8 2.2 2.6 30 CoO + 2/3 MgO MOLAR RATIO, +203 SiO2 + A 203 7T

HEAT NO. 8 1i Metallics/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50o FeSi 9.5 lb 2.:Nornmetallic s/Charge Coke 60 lb Stone (High Ca) 18 lb Spar (95% CaF2) 5 lb CaC2 6 lb Bed a. Height 48 in, b. Nonmetallics 5 % by wt CaC2 added with bed coke. 45 lb stone, 15 lb spar, 15 lb CaC2 on top of bed c. Burn in time 4 hr 4, Runner and Bottom ao Dam height 5 in. b. Tap-hole 1-1/2 in. x 3-1/2 in, (rectangular) c. Bottom Depressed 1/2 in. below tap-hole; bowl shape Chemical Analyses Samples a. Metal From runner b. Slag Front and back slaggers 6. Comments a. Blast on until tap-20 min 75

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 35 in. (6.67 sq ft) 2. Temperature Range 2650-2750 F 3. Total Carbon, Ingoing 1.33o 4. Total Carbon, Outgoing 3o95% o5 Metal Melting Rate, lb/min 99 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 14.5 lb/min Stone 4.35 lb/min Spar 1.21 lb/min Carbide 1o45 lb/min 7. Air Weight 2250 cfm at STP 182 lb/min 8. Air Pressure 14-19 oz B. Operating Data/Sq Ft/Min 1. Melting Rate/sq ft/min, lb 14.8 2. Total Coke wt/sq ft/min, lb-2 18 ao Coke wt/sq ft/min for combustion —lo79 bo Coke wt/sq ft/min for solution in iron —0o39 76

35 Nonmetallics/sq ft/min, lb Stone 0.65 Spar 0o18 Carbide 0.22 4, Air wt/sq ft/min, lb 27.3 C, Operating Ratios 1i. Air wt./i/Total Coke wt 12,5:1 2, Air wt/Metal wt i o85 oi 3 True Coke Ratio-Metal wt/Coke wt for Combustion 8.3:1 4, Apparent Coke Ratio-Metal wt/Total Coke wt 5 Nonmeta-llics-Metal wt/wt Stone + Spar + Carbide-14lo:l a. Metal wt/stone wt-22.8:l b o Metal wt/spar w+t-81.8:l Co Metal wt/carbide wt-68.2,1 6o Approximate Metal wt/Slag wt. 9.9 o1 77

CUPOLA HEAT NO.8 2500 Z 2000 I LL 1500 u 1000 5:25 5:30 5:40 5:50 6:00 6:10 6 20 6 6:30, 2800 - t 2750' 2700 E w 2650 2600 ~ l l I 5:25 5:30 5:40 5:50 6:00 6:10 6:20 6:30 25 20I Icl) 0 5 - 5!25 5'30 5'40 5:50 6:00 6'10 6:20 6:30 CLOCK TIME (PM) 78

CUPOLA HEAT No.8.04 uL.03 DJ i-.02 z w 0::.01 LJ CL 5:30 5:40 5:50 6:00 6:10 6:20 6:30 4.8 - 4.6 Z -J < 4.4 D w 4.2 z 1 4.0 3.8 3.6 I I I I I I I I 5:30 5:40 5:50 6:00 6:10 6:20 6:30 4.6 4.4 7 4.2 Q z 4.0 LUI \ o 3.8 LtJ a. 3.6,_ - 0 0 u3 OD 3.4 I - 3.2 I I I I I I I I I 5:30 5:40 5:50 6:00 6:10 6:20 6:30 CLOCK TIME (PM) 79

CUPOLA HEAT No. 8 4.0 See Fig. 3 for Location of Back Slag 5:55 3.0 _ ~~\^~ ~ 6:C0e 0 ~_ 2.0 - z Front w 5:58 I _ w 10- O (=3) z 6:30 6.18 6.06 m 0 3.^0j6:10 ~- -Ba ck 6:28(*2) 614 6:31 (#3) 0 L I_ I _ I __ I _- I I _ I I _, I I_,! I \ 0.6 1.0 1.4 1.8 2.2 2.6 30 CoO +2/3MgO MOLAR RATIO SiO +A203 80

HEAT NO. 9 1. Metallics/Charge Scrap Returns 140 lb Steel Punchings 260 lb 50% FeSi 9.5 lb 2. TNormiretallics/Charge Coke 60 lb Stone (High Ca) 18 lb Spar (95% CaF2) 5 lb CaC2 6 lb 3. Bed a. Height 48 in. b. Nonmetallics 5% by wt CaC2 added with bed coke; 45 lb stone, 15 lb spar, 15 lb CaC2 on top of bed c, Burn in time 2 hr 4. Runner and Bottom a, Darm height in. b. Tap-hole 1-1/2 in, x 3-1/2 in, (rectangular) c. Bottom Straight pitch of 1 in/f t to bottom of tap-hole (1/2 in ). C;hemical Analyses Samples a, Metal From runner'b. Slag Front and back slaggers 6, Comments a, Short burn in time ob Different bottom design co Blast on until tap-19 min. 81

A. Operating Data 1o Inside Diameter of Tuyeres (in.); (Area-sq ft) 35 in. (6.67 sq ft) 2. Temperature Range 2750-2800 F 3. Total Carbon, Ingoing 1538% 4. Total Carbon, Outgoing 3 40-3.80o 5. Metal Melting Rate, lb/min 83 lb/min 6, Nonmetallics Rate (Exclusive of Bed) Coke 12.2 lb/min Stone 3 65 lb/min Spar 1.02 lb/min Carbide 1o22 lb/min 7. Air Weight 1850 cfm at STP 150 lb/min 8. Air Pressure 12-17 oz B. Operating Data/Sq Ft/Min lo Melting Rate/sq ft/min, lb 12 4 2, Total Coke wt/sq ft/min, lb-1o86 a. Coke wt/sq ft/min for combustion —1.56-1.61 b Coke wt/sq ft/min for solution in iron —0025-030 82

3. onmetallics/sq ft/min, lb Stone 055 Spar 0.15 Carbide 0. 18 4. Air wt/sq ft/min, lb 22.5 C, Operating Ratios A... Air vt/I.Totai Coke wt 12.p 1 2, Air wTt/Metal wt 1,81:1 3. True Coke Ratio-Metal wt/Coke wt for Combustion 7.7 to 8.0:1 4. Apparent Coke Ratio-Metal wt/Total Coke wt 6. 7: 1 5.'Nonmetalliss-Total Metal wt/wt Stone + Spar + Carbide-14.1:1 a, Metal wt/stone wt-22 7: b. Metal vt/spar wt-81l 5o c. Met 4al wt/ carb ide wt 6 8l o 1 6. Approximate letal "wt/Slag w 936 1 9oL.

CUPOLA HEAT NO.9 2500 Z 2000 LL 1500 0, 1000 _ - 500 0 O l 0I I I I 8! 40 9:00 9:20 9:40 10 00 2800 LL S 2750 a: - 2700 - w LJJ a- 2650 -- w 2600 I 1 8:40 9:00 9:20 9:40 10:00 N 0 25 0 20 _ LL 51' n i r~.- \ a 5 CL W I 8:40 9:00 9:20 9:40 10:00 CLOCK TIME (PM) 84

CUPOLA HEAT No. 9 CrC.03 u. I.02 _ z w.01 _ Lii 0 w a. 0i X, I I I I,I l 8:40 9:00 9:20 9:40 10:00 4.4 - z w 4.2_> D 4.0- \ " 3.8 -' 3.6 3.4 1 I I -.40 9:00 9:20 9:40 10:00 4.6 4.4 0 Z 0 40 94.000 9:20 9 CLOCK TIME (PM) O 3.8 - a. 3.6 3.4 3.2 I 8'40 9:00 9:20 9'40 10:00 CLOCK TIME (PM) 85

CUPOLA HEAT No.9 3.0 See Fig. 3 for Location 0 of Back Slag 2.O z w 9:51 Back / or (- 2) (X ( (29:29 9:31 9:26 X. 9:5 I 0 9 9:20 Front (3^~ ~ 9:22 LJ_ 3 - 9:16 0 l l l l l l l I I 0.6 i.O 1.4 1.8 2.2 2.6 30 CoO +2/3MgO MOLAR RATIO siO2+Ai203 86iO + 86

HEAT NO. 10 1. Metallics/Charge Scrap Returns 140 lb Steel Bales 260 lb 50% FeSi 10 lb 2. Nonmetallics/Charge Coke 60 lb Stone (High Ca) 18 lb Spar (95% CaF2) 5 lb CaC2 6 lb'. Bed a. Height 48 in, b. Nonmetallics 5% by wt CaC2 added with bed coke; 45 lb stone, 15 lb spar, 15 lb CaC2 on top of bed C, Burn in time 5-1/2 hr 4, Runner and Bottom a, Dam height 5 in, b. Tap-hole 1-1/2 in. x 3-1/2 in, co Bottom Depressed 1/2 ino below tap-hole; bowl shape 5o Chemical Analyses Samples a, Metal From runner b, Slag From front slag notch 6. Comment s a, Bales were too large and had open burden bo Blast on until tap-21 min 87

A. Operating Data 1. Inside Diameter at Tuyeres (in.); (Area-sq ft) 35 in. (6067 sq ft) 2. Temperature Range 2750-2830 F 3. Total Carbon, Ingoing L,29% 4. Total Carbon, Outgoing 3060-4.30% 5o Metal Melting Rate, lb/min 76 lb/min 6. Nonmetallics Rate (Exclusive of Bed) Coke 11.1 lb/min Stone 3.34 lb/min Spar 0.93 lb/min Carbide 1.11 lb/min 7. Air Weight 2150 cfm at STP 174 lb/min 8. Air Pressure 13-18 oz B. Operating Data/Sq Ft/Min 1, Melting Rate/sq ft/min, lb 21 To1tal Coke wt/sq ft/min, lb —167 ao Coke wt/sq ft/min for combustion-1.33-lo41 b. Coke wt/sq ft/min for solution in iron —0.26-0.34 88

3. Nonmetallics/sq ft/min, lb Stone 0.50 Spar 0.14 Carbide 0.17 4. Air wt/sq ft/min, lb C. Operating Ratios 1. Air wt/Total Coke wt 15 0 7:1 2. Air wt/Metal wt 2, 29:1 3. True Coke Ratio-Metal wt/Coke wt for Combustion 8.1 to 8.5:1 4. Apparent Coke Ratio-Metal wt/Total Coke wt 6.85~ 1. Nonmetallics-Metal wt/wt Stone + Spar + Carbide-14.1:1 a, Metal wt/stone wt —22.8~1 b Metal wt/spar wt-818.8:i Co Metal wt/carbide wt —685:1i. 6, Approximate Metal wt/Slag wt 9~ 07 189 89

CUPOLA HEAT NO. 10 2500 z 2000 I4:20 4:40 5:00 5:20 5:40 6:00 2850 - 12000 r 2750 - - 2650 - 260 0 I i _ 4:20 4:40 5:00 5:20 5:40 6:00 2850 280 00 ~ 2750 - 2700 2 N w 2650 a2600 ~II,, I I I Ii 4:20 4:40 5:00 5:20 5:40 6:00 25 CLOCK TIME (PM) ~~20~~90 0 C 4:20 4:40 5:00 5:20 5:40 6:00 CLOCK TIME (PM) 90

0: 3 CUPOLA HEAT NO. 10 ).03 -- D,.02 z u.01 u X O I I I I I I 4:20 4:40 5:00 5:20 5:40 6:00 5.0 4.8 H 4.6 z -j < 4.4 C3 w 4.2 Z 0 m 4.0 3.8 3.6 - 3.4 I I I I I I I I 4:20 4:40 5:00 5:20 5:40 6:00 4.64.4 z 0 0 4.2 0 (0 04Q.6 4.0 " Hz0 0 0 u 3.8 "'L 1 - \ 3.6 3.4,.1. ~ l l i I l 3.2 4:20 4:40 5:00 5:20 5:40 6:00 CLOCK TIME (PM) 91

CUPOLA HEAT No.10 3.0 0 La 2.0- 5:38 Z 5:36 0..5:30 1.0 - 5:20 I Io^~~ 5'| ~~~5:18 0. I I I I. 1 1 0.6 1.0 1.4 1.8 2.2 2.6 30 CoO + 2/3MgO MOLAR RATIO CaO+2/3MgO SiO +92 AI1 92

APPENDIX II SUMYARY OF CHEMICAL ANALYSES OF SLAG AND METAL

SUMMARY OF CHEMICAL ANALYSES OF SLAG AND METAL Heat Time After Metal Analyses Slag Analyses Weight Ratio Molar Ratio No ( Tap C Si Mn S P FeC SiC2 A1203 S slag) CaO + Mn/ (min) S(metal SiC2 + A1205 1* 10 3.83.39.21.080.022 23 3.45 25.8 23.2 29.9 7.08 1.23.21 2.75.98 26 3.65.80.22.077.021 3.25 26.2 17.8 30.8 15.2 1.26.21 2.75 1.32 2* 6 3.91 1.03.21.058.019 17 3.89.62.23.057.040 19 4.5 26.9 19.3 38.6 9.7.66.46 8.1 1.34 39 4.2 25.2 16.1 37.4 15.6 1.20.36 12.0 1.60 44 3.62.37.21.047.020 5* 16 3.45.68 -.073 - 53 3.45.42.037 6o 2.20 32.0 35.3 26.7 2.7.72.49 6.7.395 69 1.72 25.3 23.8 37.2 10.9.70.56 15.1 1.29 72 3.45.44 -.037 82** (No. 3) 6.97** 31.4 24.9 21.9 14.1.61.04 1.08.814 90** (No. 3) 6.97** 35.4 25.8 22.3 9.1.45.04 1.08.652'.0 4 6 1.70 29.9 16.3 41.8 8.5.63.59 19.7 1.35 8 3.99.76.22.030.015 9 1.15 28.0 18.5 42.2 9.1.45.70 23.3 1.40 18 3.98 -.24.014.013 24 1.01 24.3 20.9 46.2 6.7.34.84 60.0 1. 5 10 4.24.75.23.007.020 13.72 24.1 13.8 47.7 11.0.25.61 102.0 1.96 15.93 25.0 30.3 41.3 1.1.19.57 95.0 1.06 19.50 24.7 16.5 48. 9.7.15.59 98.4 1.8 23 4.20.75.28.009.018 24.72 21.8 19.6 48.8 6.9.18.63 57.3 1.78 25.65 21.5 14.1 49.5 o10.4.17.67 60.9 2.14 28.38 21.1 26.4 47.7 3.0.16.65 81.3 1.48 33 4.20.60.28.009.018 38** (No. 3) 2.73** 20.1 13.8 44.2 17.4.40.55 68.8 2.30 6 12.94 26.6 24.5 44.2 1.34.25.48 44.7 1.19 16.43 25.4 18.4 46.7 7.00.21.57 51.8 18 24 4.36 -.28.013.016.43 22.2 19.1 41.4 9.6.19.58 52.7 1.62 29 4.30.81.27.009.016 1.01 20.8 18.7 38.9 15.9.23.64 58.2 1.80 31.96 20.2 25.6 48.7 3.7.23.61 55.4 35 4.28 -.27 -.014 39 1.6 19.0 11.2 33.5 25.1.14.69 62.8 2.38 43 4.08.74.27.009.014 52** (No. 3) 4.60** 17.4 16.3 32.0 21.6.65.64 58.2 2.07

(Continued) Time After Metal Analyses Slag Analyses Wei ht Ratio Molar Ratio No. ( )Tap Si Mn S P FeO Si2 A 203 CO MgO Mn S 1 (mmn) 25S(metal) SiO2 + A1205 7 6 4.o05 1.50.28 9 2.24 28.8 28.4 36.2 2.83.56.6 16.6.91 13 1.45 31.6 19.4 36.0 4.53..6 17.1 1.00 16 3.73 1.04.28.038.016 17 1.84 35.6 21.6 36.0 2.01.59.68 21.2.843 20 1.73 30.7 25.9 37.8 2.45.58.61 19.1.97 22 3.72 1.06.29.032 - 1.33 5.6 35.1 36.7 1.10.54.75 25.4.813 28 3.69 1.03.29.029.014 34** (No. 2) 3.65.99.25.030 - 2.04** 23.1 21.2 36.0 16.14.63.54 18.0 1. 41** (No. 2) 1.05** 23.7 24.9 37.8 11.14.s8.6622.0 1.3 43 3.68 1.02.25.030.019 45** (No. 3).79* 23.8 29.4 39.6 1.26.48.65 21.7 1.06 8 5 3.1 33.05 32.5 26.6 3.0.45.1 4.8.605 7 3.95 1.32.28.031.045 8 1.86 28.9 24.7 35.1 7.19.40.45 1. 1.03 12 2.45 23.8 19.1 43.4 8.4o.45.70 31.8 1.57 16 3.94 1.25.33.022.023.79 22.3 24.7 45.4 3.74.18.77 35.0 1.42 \o9 ~ 20.79 21.1 20.1 4.4 9.81.13.75 34.1 1.77 vr^ ~ 24.61 20.7 23.5 43.5 9.54.19.78 45.9 1.63 27 3.94 1.02.31.017.027 28.82 20.3 29.4 44.6 2.38.19.83 48.8 1. 32 3.93 1.05.28.021.036 38** (No. 2) 3.65 1.13.29.015.027.61** 20.8 29.0 42.7 4.41.28.57 38.0 1.33 40** (No. 3).79* 20.9 30.5 43.2 1.84.26.55 36.7 1.24 41** (No. 3).61 21.0 28.8 44.2 2.63.26.61 40.6 1.2 9 2 4.05.98.26.025 - 6.56 27.5 18.6 45.9 4.35.14.65 29. 1.40 7 3.42.92.26.022.013 10 1.04 27.6 17.7 45.0 6.10.31.62 34.5 1.43 12 3.45.88.29.018.016.96 27.8 19.8 44.9 4.21.32.67 37.2 1.33 16 1.25 27.1 10.3 46.7 11.72.32.58 26.0 1.86 17 3.35.72.33.020.016 19 1.20 26.6 16.4 46.1 7.16.32.70 35.0 1.6 21 1.25 26. 4 14.7 46.0 8.27.48.66 30.0 1.64 22 2.38.65.31.022.o16 27 3.80.43.29.019.012 32 3.65.5.28.018.014 5' 53.43.82.30.01o8.018 41** (No. 2) 1.535 24.2 27.9 40.4 3.38.63.48 27.6 1.1 453** (No. 3) 1.11** 24.8 21.4 45.9 4.66.57.54 31.8 1.44 47 3.4 1.10.43.016.022

(Concluded) a Time After Metal Analyses Slag Analyses.Weight Ratio Molar Ratio Heat Heat ~ Tap l | S(slag) CaO + 2/~ MgO No. Tap C Si Mn S P FeO Si02 A1203 CaO MgO MnO S S a) aO + 2 Mg (min) S(metal) Si02 + A1203 10 2 4.52 1.29.31.006.012 7 4.36 1.10.29.007.011 13 4.44.81.29.006.010 18 3.66.71.26.010.010 19.94 23.02 14.02 28.97 8.98.09.64 64.0 1.97 21 1.08 21.36 6.85 53.54 12.31.10.77 77.0 2.74 27 3.75.80.29.010.012 31 1.23 22.08 5.76 50.57 15.49.19.89 81.0 2.61 33 3.54.24.24.011.008 37 1.22 22.43 5.64 50.14 16.41.16.76 69.0 2.74 39 3.60.44.25.016.010 1.72 22.28 11.18 49.11 13.86.20.75 46.9 2.31 44 3.58.21.21.013.008 50 3.39.19.21.019.007 57 2.85.10.18.024.006 *The first three heats used dolomitic stone; the rest used a high calcium stone. **Refers to slag taken from the back. See Fig. 3 for exact location. k0 O\ Note: All heats except No. 10 used steel punchings (No. 10 used bales). All heats except No. 7 had a calcium carbide addition.

UNIVERSITY OF MICHIGAN 3 9015 02826 III 3468 3 9015 02826 3468