Experimental work involving the substitutionof manganese for iron in copper mattes

Item Type text; Thesis-Reproduction (electronic)

Authors Potter, George Michael, 1914-

Publisher The University of Arizona.

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EXPERIMENTAL TOKK INVOLVING THE SUBSTITUTION OF MANGANESE FOB IRONIN COPEER MATTES

By

George M* Potter and Merle D. Sohmid

A Thesissubmitted to the faculty of the

Department of Metallurgy

in partial fulfillment of the requirements for the degree of

Master of Soienoe

in the Graduate College University of Arisona

1 9 3 6

Approved:Majo: o feasor Date

ACKNOWLEDGMENTS

The experimental work desoribod In this thesis efcs per forms d in the laboratories of the U. 3. Bureau of Hines, Tucson station, by the anthers, who, for the academic year 1936-1936, were the Bureau of Mines Fellows at that station. . ‘

The work was divided equally between the authors; M. D. Schmid doing all the work in connection with the series containing 20 and 6 per cent copper in matte; and G» M. Potter doing all work in con­nection with the series containing 30 and 40 per cent copper in matte.

In addition to work mentioned above, another series, 10 per cent copper in matte, and 30 per cent silica in slag is included in this manuscript. This series was made in part by Mr, A* H. Bober sen, and in part by Mr. F. 3. Wartman, of the U. S« Bureau-of Mines staff.

The authors wish to express their warmest thanks and appreciation to Mr. F. 3. Wartman, Associate Metallurgist, U* S. Bureau of Mines, for his guidance and aasiatanoe on this re sear oh project throughout the year; to Mr. A. H. Roberson, junior Chemist, U. 3. Bureau of Mines, for his analytical work in eomxeotlon with the problem; to Dr. T. G. Chapman for his aid and advice in the preparation of this manuscript.

e O K T B N T S

Chapter

I« Introduction............................

II* igpar&tue. Materials, and AnalyticalMethods .... . ....... ..............

III. Experimental Work Leading to The Develop­ment of a Satisfactory Orneible......

IT. Preliminary Experimental Work. ......• ■ - ■ ■ f ' r' . 1 ' . - < * ......

T. Experimental Work. .....

Precision and Final Method ofMaking tolte.V....................

Experimental Data........ .Interpretation of Basalts.......... .Errors................... .Sumaary and Generalisation..........

page

1

3

5

11

16

161818*36

F I G U R E S

fig* me. same1* BydraalioPr^sa.............. ............2. Pr«8«rar« Gauge...........................3. Aeeenbled l$ol4.................... ......4. Mold Parts Shoeing Cruoltle la Beeltlon. •..5. Magaesls erimlMe Saturated alth Maaigaaeae

Slag . . .... ........... ..........6. Charge Constituent Seigfrts................7• Seetloa et Cruoihle Kith Melt........8 • BietrIVatloa Batlo of Manganese

(All Melts 20g$ to Matte)..........9. Dletrlhutloa Batlo of Manganese. .

(All Melts 30^ Cu la B^fcte).........10. Blatrlhatiea Batlo of Manganese

(All Melts 30^ Slog la rn.sg).... .11* Photograph of Spaee Model.......;...*......

-:s- ■: ••

18. Distribution Batlo of Fe and Mn............- ' v : • ' -15* Diatrlbution of Fe and Mn ................. ■ V - : -14. Bffeet of Agglosaritlea...................

page5S

•78

91517

'< . . . ..:

85

86

8789503234

J U U L >l*-a

Table Ho. ' Hose ' : ' ' ' pages1. Oeispeettlen ef Miseraiii Ueed.. i............ 3

2. Drrlatiene of Copper and Sillos, Per Cent M 18

3. Malytloal Data..................... . 19 - 21

4. Dlstrllmtlea Batlea. ..... 22 - 24V. . , ■ ' - ■ • ■ : ' r ' : ' ' J ■■ ' < -

6. Effeot of Varylng The Ratio of Matte aod: - ............. ..... * .

EXFEHIUESTAL WDBK IKVOLVIKG fEB SDBSTITDTION OF MA16AHBSB FOB IBOHnr OOEHB MATTES

; % - ; OHAPTEB I - IHTROEOOTIOir

The world produotion of nangaaese ore for the year 1934 waa about 8,800,000 metric tone; Buaala being credited as the principal producer.Of thla total production the United States produced 86,940 metric tone.

.Henerer, 368,219 metric tons vrere ooaauasd in the United States; the bal­ance, 341,339 metric tons being Imported.

Manganese ie an essential uar metal, and since there are extensive domestic low grade deposits, the problem of concentrating these ores is of national interest, ore dressing and hydromatallurgioal methods of treating manganese ores hare been used, and under the stress of ear time demand mere commercially successful, although recoveries mere low.

The experimental work described in this paper is the first step in an attempt being made by the U. 8. Bureau of Minas to develop a pyro- metallurgioal method of concentrating manganese. This project involvest first, the substitution of manganese for iron in copper mattes; second, the concentration of this manganese as oxides in a special slag resulting f*om a high temperature converting operation In uhioh no fluxing silica is used; and third, the reduction of this oxide slag, which would contain in addition to the oxides of manganese more or less iron oxides, and the im­purities copper, sulfur, and possibly phosphorous, to give Impure ferro­manganese.

V Kieesling, 0. S. Minerals Year Book U.S.Govt. Printing Office (1936) pages 466,471,482

The experimental work deeoribed in this paper is eonflermid with the first step in the propoeH process, namely to determine to what extent man­ganese earn be substituted for iron in copper mattes; :

A survey of the literature revealed only one reference on the subject of this investigation; a U.S. Patent by Anson G. Bette*

"Process of recovering manganese from material containing manganese and silica which consists in smelting said material with addition of a sulfide other than of manganese, producing fused manganese sulfide, fused metallic iron and fused slag containing the silica ef said material, converting said manganese sulphide to manganese oxide and reducing said manganese oxide to metallic manganese •" 2/

In connection with the mechanical handling of oxide slag without the addition of fluxing silica* no reference could be found in the literature, but it is known that a large Southwestern copper company has, in a high temperature operation, successfully converted eepper matte without the addition of fluxing silioa, producing a liquid oxide elag which could be peered.

1/ Bette, A. G. The Art of Smelting Manganese U.3.Pat.Ko.1,703,657 0, 8. Patent Gasette Feb. 26, 1989

CHAPTER II-APPAMfUa, MAZSBIiLS, AMD AHAilMOiL METHODS

?v': . .■ . . ' •. : , •APP1HAT03

The furnace used was a 3 K\TA Ajax high Amqueaoy el#@%m-WW#tion fnr- naee, itiiloh had the staaAaH mrcury lajNprn^ttng are replaced by aa adjust- able one from a larger furnace*

The furnace was controlled during the eeltlng operation by taking fre­quent temperature readings with a Leeds and Borthrup optical pyrometer, through a small hole In She furnace 1MU

...... .... ' ' ' ' ; HASKBIAL8 ' " .

In order to simulate conditions found in commercial practice, minerals mere need in preparing the synthetic melts. Table 1 gives a list of the minerals used and their compositions*

TABUS 1 - OGBPOSITIOH OP MHBEALS USED

MIKEHAL FOBMOLA EBB (3EET BY Y/EI«fPa 3 Hn Cu 810* Mg

Ohaloooite w .,

21.4 78.4Magnetite 1*804 68.6 6.2-Pyrrbotite Pa# 60.6 31.3 1.7 8.2Quarts SiOg 1.0Bhodochrosite KnC03 41.8 2.0

AHALYTICAL IffiTBODS

To datermiM the extent which manganese had replaced iron in the copper mattes resulting from the numerous experimental melt# made in this investi­gation, it was necessary to have quite complete analytical data regarding the composition of both the matte and slag of each melt. The mattes were analysed for oopper, iron, manganese, and sulfur; the slags for copper, iron, manganese, magnesium, and silica. The copper, manganese, magnesium, and sil­ica analyses were made by Mr. A. E. Bober son, JSnicr Chemist, Tucson Station, 1. S* Bureau of Mimes. The iron and sulfurs were determined by the authors; the iron determinations being run volumetrioally by the diohromate-dlphenyl- amine method, and the sulfurs being determined gravimetrioally aa bariumsulfate.

CHAPTER III - EXPERIMENTAL TOHK LEADING TO THE

IffiYELOPMEan? OF A SATISFACTORY CRUCIBLE

Inasmuch as cruolblea which would meet the requirements of this ex­

perimental work were not available on the market, it was necessary for

the authors to prepare them# The development of a method of making satis­

factory crucibles proved to be a very difficult and lengthy problem,

so much so that three months were devoted by the authors In solving it#

It was originally planned to use hand-tamped crucibles made In a

tapering mold, but preliminary work indicated that these were unsatis­

factory# In order to make a crucible of a more dense and uniform character,

a special mold and hydraulic press were designed#

The hydraulic press used for making crucibles is shorn in Figure 1.

FIG.I — HYDRAULIC PRESS

6

The hydraulic pressure was obtained by using a standard 7-ton capacity Blaokhawk automobile Jack (Model No# C-3-9). The press frame was con­structed by the Tucson Iron Works# The pressure gauge (Fig.2) was designed and constructed by the authors# This gauge was merely a means of magnifying the stretch of the two 1^-inch steel rods which made up the frame, and in­asmuch as this stretch was proportional to the total force applied, the de­flection of the gauge was proportional to the applied pressure# The scale was calibrated by taking advantage of the uniform breaking strength of pine and oak blocks# Cubes of pine and oak were cut from one by one inch

stock and the blocks marked serially as out. Odd-numbered blocks were then compressed in a standard Tinius Olsen materials testing machine,

with pressure applied parallel to the grain, and the breaking loads noted#

7

The breaking strength of these approximately one inch cubes was sufficiently

constant in all samples; the average of the oak being 10,050 and of the pine

4,950 pounds. The even numbered blocks were then crushed in the hydraulic

press, the deflection of the gauge pointer noted, and the scale calibrated

accordingly.

The mold (Figs. 3 and 4) was made by the Tucson Iron Works from four

pieces of one inch steel boiler plate. The plungers were made of tool steel

and fitted into the mold with considerable clearance.

F IC r.3 - ASSEMBLED MOLD

2/Previous work by Butler, confirmed by the authors• experience, indi­

cated that crucibles made from minus 200-mesh Periolaee (commercial MgO of

about 95 per cent purity) were subject to serious checking. Reference in

5/ Butler, Gurdon Montague, Jr. Methods for the Decomposition of

Copper Ferrite Thesis, Library Univ. of Aria., 1934 page 4

8

the literature Indicated that this objectionable condition could be over­

come by aiming the product and then zecombining the coarse and fine par­

ticles, keeping to a minimum the intermediate sises. After considerable

experimental work along this line it was found that a satisfactory crucible

could be male by using 20 per cent minus 66 plus 160-mesh and 80 per cent

minus 200-mesh Periolase, the latter fraction, after screening, having been

ground in a laboratory ball mill for four hours. Crucibles made from this

- ' i

FIG. 4 - MOLD PARTS 330WIXG CRUCIBLE IS POSITIOB

mixture proved to be very resistant to checking and could be made with a

minimum of failures. These Periolase crucibles had, also, the advantage which

was not present with Diamel crucibles, of breaking away from the slag easily.

4/ Troatel, L. J. Recent Developments in Manufacturing and Using

Refractories Cham, and Met. Eng. Vol.42, No.7 July,1935 page 363

However, later experimental work proved that these crucibles had a large

percentage of voids, and when melts high in manganese were made in them, the

very fluid manganese slag was appreciably absorbed by the crucible (see

Fig.5). In this microphotograph, the dark areas are the original voids which

have become saturated with black slag, and the light areas are Periolaae.

9

FIG. 5 — V: AGEES IA CRUCIBLE SATURATED WITH MAHGAKE3E SLAG

Due to the difficulty encountered in fusing melts containing manganese,

in Feriolaae crucibles, further investigation in making crucibles was con­

ducted using other refractories. Aluminum silicate was tried, but rejected

because crucibles made from this refractory provided a source of silica

which allowed uncontrolled amounts to enter the slag.

Finally a satisfactory refractory was found in Diamel (oomneroial mag­

nesium aluminate; 95 per cent LgO.AlgOg). Crucibles made from this material

proved to be very resistant to checking and extremely impervious to the man­

ganese slags. The one objection to these crucibles, however, was the fact

difficult totiist the slags adhered tenaeiously to the crucible and was remove quantitatively.

The procedure finally developed in making the Diesel crucibles was as flllovsi Sight euble centimeters ef isoanyl alcohol were mixed thoroughly with 110 grams of Dlamel, and this mixture temped into the mold, tie Inside of which had a thin eeat ef lubricating oil. The mold was then placed in the crucible press and 15,000 pounds pressure applied for a period of about one minute. While the pressure was still being applied, the plunger in the base of the mold was made feet by means of two set screws. The pressure was then released, and the mold containing a cylindrical block of Dismal two inches long was taken from the press and placed In a lathe. The plunger which was held in place by the set screws was left in the mold to protect the bottom of the crucible. The meld was placed in the chuok of the lathe, the attached plunger to the back, and all but about one-eighth inch walls and bottom of the cylindrical block of Dlamel was turned out by using a special tool. The mold was removed from the lathe, placed in a vise, disassembled, and the crucible carefully removed.

The crucible was then placed in an eleetrio muffle furnace. The fur­nace temperature was raised slowly to a dull red heat, thus drying and partly sintering the crucible* In this state, the crucible was sufficiently strong to be handled safely. The omoible was given a final sintering in the in­duction furnace, using a carbon heating element. The temperature was raised to 1750 degrees 0., in one half hour, held there for five minutes, and then dropped. After cooling in the furnace, the crucible was removed, inspected, and weired; it was then ready for use.

CHAPTER IV — PRELIMINARY EIPEEIMEKTAL WOEK

a:,,'--' ■ : • :• . ■ " /' ' ' 5.1The concensus is that manganese will replace iron in sulfides and oxides,

according to the following equations:

(1) FeO + Mn - m o + Fe

(2) FeS ♦ M b ■ M qS ♦ Fe

Subtracting equation (2) from (1), the following is obtained: .

(3) FeS + MnO - MhS ♦ FeO.•* •' *. • •

Free energy data indicated that this reaction should take place from left to

right at room temperature; However when the free energies were corrected for

sensible heat in the reactants and products to the temperature (1300 degrees

Centigrade) at which the reaction would take place in a copper reverberatory

furnace, this reaction might or might not take place, according to celculae-

tlons based upon sensible heats quoted by various authorities.

The original plan was to fuse a great number of 30—gram charges in mag­

nesia crucibles using the induction furnace; these charges were to have been

made by combining the proper amounts of ehaleocite, rhodochrosite, pyrite,

and quartz to give the calculated percentage of copper in the matte, silica

in the slag, and the proper ratio of FeO to MnO; the rhodochrosite was to have

supplied the entire oxidizing power and the pyrite the entire reducing power.

It was planned to cover the coranercial limits in percentage of copper in

the matte and silica in the slag by making two sets of melts, one with 20 per

cent copper matte, and the other with 30 per cent matte; for each set there

were to hare been seven series, covering a range of silica contents in the

SI Rosenholtz, J. L. The Elements of Ferrous Metallurgy

John Wiley and Sons (1930) pages ,36, 71

6j Wartinan, F. S. Associate Metallurgist, H.S.B.M. Personal Ccmmmication

It

9lag f*OB 20 to 56 per oeat, in 2#- per cent steps; and in each series, with 9k eonetant percentage of allies in the a lag and copper in the matte, to vary the ratio of Mao/feO from l/S to 5/l in etepe.

Oalenlationa indicated that slag and matte wights wnid vary a great teal dnring the chaage of Kno/Peo ratio; and although theoretically this variation would not affect the results, some concern w s felt as to the com- parahility of the data thna ohtainet. This fact together with early prelim- inary work resulted in an entire change of plan of attack on the problem.

Preliminary teat wits using the minerals originally planned showed that an unusually high temperature (1660 degrees Centigrade) was required to effeet etnspleto melting; at this temperature no crucible eould be made by the authors which would successfully hold the melt. Inasmuch as synthetic melt# comparable to coamaroicl practice, which smelted at the normal temp­erature, had previously been made in the furnace by Mr. P. 3. Wartman, it was decided to determine systematically what w a eaaeing the necessity for the.unusual smelting temperature. A charge which melted at a normal temper­ature was taken, and one by one each mineral used was substituted by the eerreeponding mineral to be need in this study. This investigation showed that when pyrite was replaced by pyrrhetite a normal smelting tmuperature could be employed; a possible explanation being that the sulfur and sulfur dioxide given off by the pyrite caused frothing of the melt, and tl» resulting increase of surface caused such rapid cooling that a high temperature was required in order to melt down this pumice-like aintered charge.

The change from pyrite to pyrrhetite was made, and a number of teat melts smelted. This preliminary smelting showed that owing to the great numl>er V M ’iablea in the work it was practically iapoeeible to calculate

exact, charge required to give a melt of pre-determimed ccapccitiou; and to order to obtain in a given melt the desired silica content of the slag

IS

and copper content of the matte, it was necessary to make by trlal-and error method a great munber of trials. .

Study of the results of the work to this peint gave rise to a plan of establishing a standard melt containing no manganese, using an oxide of iron to provide the oxidising poner, and substituting rhedeehreeite for the iron oxide in successive steps, or substitutions. Both hematite and magnetite mere tried; better reanlta mere obtained using magnetite, and accordingly it sms need in enecedlng melts.

The first test melts mere made using minerals ground to minus 66-mesh; honever, mioroeoopio examination of the slags ehened partlelee of quarts nhieh had net reacted. In order to facilitate complete reaction, the quarts was soreened, all exoept the minus 200-mesh discarded, and this fraction ground for six hours in a laboratory ihbey mill, using ailex pebbles; this very fine product was used for the source of eiliea in all subsequent melts.

When melts sere made of chargee containing this fine silica, there was appreciable dusting, and because melts could not be reproduced, it was felt that this ducting less was of a selective charaeter. In order to minimise such leasee, the charges were thoroughly mixed with 0.4 or 0.6 gram of dex­trin, moistened with 4 oc of water, foreed through a 10-mesh screen while daaq?, and d r M . This agglomeration out dusting leases materially, enabled tbe anther# to reproduce results, and as will be shown later had no apprec­iable effect upon the Mno/FeO ratio.

Owing to the fact that, as previously mentioned, it was isposaible to •aleulate directly the charge necessary to make any given melt, a method was evolved which, for a given ear lee, materially cut down the work necessary to. product melts of predetermined ooapoaitiona. The base melt and the last substitution (i.e. the melt containing no rhodoehroaite and the melt having

all ef the magnetite substituted by rbocLoohrosite, respectively) wre made for each series by a trial and error method; first making a melt, analysing it for copper in the matte and siliea Is the slag, and then changing the pro­portion# of the minerals to give melts of approximately the same vei#t ef ttatte, namely 16 grams, as slag, and vdiioh analysed the proper percentage of copper and ailiea. If them# conditions were not fulfilled by the first cor­rection, a second correction was made; in some eases as many as six trials wre necessary to establish a given melt. Once these two melts (substitution numbers 0 and 5 or 6) were successfully made, it was an easy matter to make a graphical weighted average and obtain any substitution desired, eorreet on the first try.

Fig* 6 shows suoh a graph, this particular one being for the series of 35 per cent eilioa in the slag and 20 per cent copper in the matte. Prom left to rigit on the abscissa were plotted substitution numbers, and from

< Wttom to top on the ordinate were plotted weight of each mineral used in the charge in grans. Thus at substitution Ho. 0 (base melt) the vertical die- tanoes reisresented the weights of each mineral used, and the sane was true S* respect to substitution Ho. 6 (complete nQilacemeat of magnetite by rhodo- ohrosite). Lines joining the corresponding points on Ho. 0 and Ho. 6 inter- •ected the vertioal lines for eaoh substitution at the proper weight of the # m r a l to be used in order to obtain a melt of the desired composition.

Cc^sfi / i/t r

I-JOT

OF CHSBffiB'll

15

FIG. 6

CHAPTER V - EXPERIMENTAL ISOBK

PRECISION AND FINAL METHOD OF MAKING MELTS

The method finally developed in making the melts was as follows: The

Iron ring was placed in the furnace and surrounded with magnesia, the lat­

ter "being used to protect the furnace lining from the iron oxide formed

en heating. The Diesael crucible, made as described in Chapter III, was

lowered into the center of the iron ring, the lid of the furnace replaced,

and the furnace brought up to charging temperature (1160 to 1200 degrees

Centigrade), The agglomerated charge, previously described, was then

added, a small amount at a time, to the hot crucible by means of a funnel

with a quarts stem which was inserted into the furnace through a hole in

the lid. When all of the charge had been added, the temperature was

raised to 1300 degrees Centigrade and held there from ten to fifteen min­

utes in order to Insure complete separation of the matte and slag. The

furnace temperature was then slowly decreased, and when the crucible was

below a red heat, it was removed from the furnace and oooled to room

temperature in the air. The crucible was then broken sway from the matte

and slag, and the last traces removed by grinding on a special emery wheel.

The matte and slag were then prepared for analyses by grinding in a Platt-

ner morter. Fig. 7 is a section of a typical melt, showing the matte,

■lag, and the crucible.

Somewhat more than 100 melts were made according to procedure des­

cribed, but, owing to the necessity of establishing the base melt and last

substitution of each series, as previously mentioned, by trial and error

methods, approximately half of these melts were used only as guides in

making melts of the required composition. After some 10 or 15 melts had

17

been made it became apparent that uncontrollable errors made It impos­

sible to reproduce melts closer than / 0.5 per cent in the percentage of

silica in the slag and copper In the matte. Accordingly an arbitrary

tolerance was set at / 1.0 per cent, and all subsequent melts were accept­

ed and analysed providing the copper and silica were within one per cent

of the calculated values. When the experimental data were finally studied,

it was found that the average deviation of the copper and silica from the

calculated value was almost negligible. Table 2 gives the average and

mean deviation of the per cent of copper in the matte from the calculated

value for 45 acceptable melts.

18

TABLE 2 - BBYIATIOBS OF (X)ITER ABB SILICA., EER CENT: OOEEBB IB MATTE SILICA IB SLABBBAB

DEVIATIONA i m u mDEVIATION

BEANDEVIATION

AvmifiiDEVIATION

0.39 >0.04 0.58 -#•0.07;

EXPEBIMEHTAL DATAThe weights of minerals used in the charges and the analyses of the

■site and slag for all of the acceptable melts are recorded in Table 3. fhis table is arranged according to sets and series of the several per­centages of copper in the matte and silica in the slag.

' iraBEBHASIOl OF USOLIS

Table 4 gives, for each set and aeries of melts, the per cent of ganese in the matte and the distribution ratio of manganese between the Slag and matte (obtained by dividing the percentage of manganese in the \ slag by the percentage of manganese in the matte).

The three graphs. Figs. 8, 9, and 10 were plottW from data taken di­rectly from Table 4; each will be explained and interpreted in turn. It was found by experiment that when the log of the distribution ratio of manganese between the slag and mat# warn plotted.against the percentage of manganese in the matte a straight line resulted for each of the tenseries discussed in this paper. Accordingly these three grsqphs, as wellas ones to be explained later. were. plotted on semi-leg paper. In eachease the manganese distribution ratio was plotted on the vertical coord­inate ," i • e,- the log scale • * .. — • - ~ .....

The trends of the distribution ratio for the three series of melts, containing respectively 25, 50, and 35 per cent silica in the slag and in

TABLE 3 - ANALYTICAL BATA

MELTCHABGB WEI SITS, GRAMS ANALYSES, PER CMT

; MATTE ; : SLAG ;NO. Magne­tite

KBodo-chrosite

Chair- Pyrr-hotite

Sill- ';cocite ca ; Cu Mn Fe "s i Si0s Mn Fe S Cu Mg

i l m13.5 ;

1.1 : 14.4 2.7 5.6 ; 60.4 22.0 31.2 37.0 2.7 0.6 3.5i i

I a 1 1 19.3 6.7

j1.1 14.9 3.0 6.1 .6.2 53.5 23.3 29.8 10.4 25.2 3.0 0.5 4.4

■So 109 4.5 13.3 1.1 15.4 3.2 6.1 14.2 43.9 24.3 30.1 19.5 19.9 3.7 0.5 5.0fl oiI s ”

20.0 1.1 15.9 3.6 5.9 23.0 33.4 84.9 ' 29,9 25.5 14.4 5.0 0.7 5.3

p -•

. 4 .9.9 : ; *• t , ; ' V * .

30.3i 0.6 4.9

Sfl ”-13 11.7 2.8 2.1 13.7 3.3 10.1 2.2 89.8 4.2 0*7 6.7■?<? W-l« 7.8 : 8.4 2.1 14.1 •3.5 10*3 7.6 29.7 13.0 0.6 5.06S ’ ■' . S v ' : '

3.9 14.0 2.1 14.5 ; 3,5 9.7 15.2 ' 29,7 80.1 0.7i

6.8

p - 17.0 . 4.0 10.8 4.0 20.1 : ■ 47.6 21.1 25.6 44.1 3.2 1.4 3.7^ 5 67 11.3 8.0 4.4 11.4 ; 3,5 80.1 5.8 41.8 81.4 25.4 12.1 31.6 3.4 0.7 4.4a . ,

8S 6 95.7 16.0 4.8 11.9 ' 3.1 20.1 14.0 34.5 22,1 25.9 23.4 19.6 3.7 0.7 4.8

I t 65 24.0 8.1 12.5 2.8 19.3 23.1 22.8 21.4 25.6 51.2 10.8 3.3 1.2 5.8

? S "SEj HM: 13.1 • . 4.0 10.9 3.8 20.3 48.0 23.4 30.4 37.8 1.4 0.7 4.53 a4 "

8.7 8.0 4.1 11.5 20.1 5.4 41.0 23,8 29.2 12.5 27.9 3.4 1.4 3.75 ro 95 4.4 16.0 4.0

i12.2 4.8 19.2 10.8 33.3 23.7 30.4 21.7 18.3 2.8 0.7

$ $ 89 84.0 4.3 12.6 5.1 20.0 88.4 24.9 24.6 28.8 33.5 12.1 4.0 1.8 , 3.5

TABLE 3 - ANjJLTTICAL D m (CGHTZBQXD)

MELTNO.

CHARGE WEIGHTS, GRAMS ANALYSES. per c m . '-J- -

Hagaer- tlte ;

Rhode-chrosite

Chal—cocite

Pynr-hotite

Sili­ca

MATES • - - ■ ■ ayys - ---- • - --- -Ca Mtt 7e S Si0a Mn Fe S Cu Mg

v » 77 14.0 ; 4.0 11.9 6.0 20.3 48.0 24.9 35.6 36.9 1.5 0.6 2.9t? d .,. . . . , . , « V ■a a 83 9.3 CD O 4.0 12.2 6.3 20.5 5.0 42.2 25.8 35.1 13.1 26.7 1.9 0.5 3.2?« 85 4.6 16.0 4.0 12.5 6.5 20.1 12.0 35.6 26.4 35.0 23.8 17.7 2.2 0.5 2.8s s ' .. . .. - '

f t81 1 24.0 4.0 12.8 6.7 19.7 22.0 26.0 25.6 34.2 31.3 11.3 3.2 0.7 3.5• ' >

52 13.2 6.5 9.0 2.9 29.5 40.8 21.4 25.1 43.3 5.3 2.9 6.2II M 11.6 2.8 6.4 9.2 3.0 30.7 1.8 37.8 21.8 24.3 5.8 40.2 3.6 2.6 3.9

** 58 10.1 5.6 6.4 9.4 3.1 30.1 3.8 37.9 21.2 26.0 10.7 33.3 1.9 0.7 6.8*g - ... - - ■ '■ ■gs 56 8.5 8.4 6.3 9.6 3.1 29.4 6.3 34.4 22.2 24.0 13.5 27.0 2.7 2.1 4.2

ft 6® 7.0 U . 2 6.2 9.8 3.3 • 28.8 8.9 32.2 22.2 24.2 17.6 24.1 2.5 1.8 5.2

48 5.4 14.0 6.2 10.0 3.3 29.3 10.6 30.5 22.5 24.5 21.8 22.22.8 1.1 6.8

22 13.7 5.2 8.6 4.7 29.5 41.5 20.7 29.7 40.1 3.6 2.0 5.7

28 12.1 2.8 5.1 8.6 5.1 29.9 1.5 37.9 22.7 31.3 5.1 38.2 2.5 1.0 4.5

si 30 10.5 5.6 5.0 8.6 5.6 30.9 2.5 36.2 24.1 31.4 9.4 #3.1 2.1 0.9 3.9S toa a 32 9.0 8.4 4.8 8.6 5.7 30.0 4.2 35.3 24.2 31.2 14.7 28.8 2.1 0.7 5.0a «36 7.5 11.2 4.7 8.6 5.9 29.4 6.2 32.6 24.5 31.5 18.8 25.6 3.1 1.7 5.6

tt 38 5.9 14.0 4.6 8.6 6.2 29.1 8.0 30.6 25.6 30,1 21.2 21.1 3.1 2.0 5.7

42 4.3 16.8 4.6 8.6 6.3 30.1 11.9 26.3 24.5 30.3 23.8:16.3 8.3 0.9 6.2

." ..— --- --- --r

TABLE 3 - ANALYTICAL DATA. (CONCLUDED)

MELTNO.

CHAKGE WEIGHTS, GRAMS ANALYSES. PER CENTMATTS SLAG

Magne­tite

Ehodo-chrosite

Chal—cocite

Pyrr-hotite

;04 1 4—olJLloa On Mn Ye s SiO* Mn Ye S : .. Cu Mg

S 3 84 n.i 5.5 9.9 5.5 30.7 39.3 24.7 35.6 : 32.6 1.4 1.0•g w

86 9.5 3.0 5.4 9.0 5;6 29.2 1.5 37.3 24.0 34.1 5.0 32.3 1.7 1.3 3.5!

5 3 88 6.4 9.0 5.4 9.1 5.7 30.0 4.3 28.7 24.1 34.8 14.4 22.2 1.5 0.5 3.878 3.3 15.0 5.3 9.2 5.9 29.7 11.6 27.9 25.1 34,5 24.7 15.5 2.1 0.6 4.9(A BO !

100 13.7 9.1 8.6 5.2 39.5 30.0 21.8 30.4 39.0 1.1 0.8 3.8108 12.1 3.0 9.1 8.6 5.3 39.4 1.0 29.2 22.7 30.5 4.9 32.8 1.6 1.5

a=“ no 9.0 9.0 9.1 8.6 5.5 40.0 3.6 25.7 23.0 29.5 13.5 25.6 1.8 1.7 '5 M i

If 102 5.9 15.0 9.1 8.6 5.6 40.3 7.4 22.5 22.8 29.0 21.2 19.9 1.6 0.7 3.8

13 13.1 : 4.1 10.9 3.6 20.5 49.6 21.9 29.5 : 39.2 2.2 0.8 5.4

8 $ 19 11.6 2.8 4.1 10.7 3.5 20.3 2.1 44.4 21.6 30.3 5.4 36.2 3.0 1.3 3.3

$ 3 39 9.2 5.6 4.4 13.5 3.7 19.6 5.6 44.2 24.6 31.1 10.5 31.8 2.5 0.6 4.3

i s 27 5.3 8.4 4*8 14.3 2.5 19.5 7.1 40.8 24.4 29.8 15.7 25.7 4.3 2.0 4.4■s w

l41 5.3 11.2 4.7 14.3 3.5 19.9 9.3 38.4 24.7 30.5 18.1 20.4 2.3 0.7 6.5

ii 53 2.0 14.0 5.3 16.0 2.5 19.6 13.6 30.5 25.2 29.2 20.8 15.8 3.3 1.3 6.9

?*la 49 16.8 5.0 14.0 2.7 20.7 15.4 28.0 24.1 29.7 23.5 12.7 2.7 0.6 7.8

S I'd 106 2.7 13.4 6.4 9.6 4.0 30.0 11.3 25.6 23.4 30.3 22.0 16.0 2.3 1.2v4 T3 ̂► <a 94 1.0 10.0 8.2 11.4 1.2 30.5 11.5 22.5 22.8 29.6 21.1

(a) Series in which the ratio. -_____ ______ ■ ---« -• ■------------------------- *..... * ---- - • • —

of ma-;te and slag male Its IM** Tflrteo

(a)TABLE 4 - DISTBIBUTIOH BASICS

22

MELT BO. EBB GENT Mh IB MASSE DISTRIBOTIOff RATIO

, ' . 1076 EER CESSOn IB MATTE; 111 6.2 1.62SO FEBCEHT 109 14,2 1.58SlOo IK SLAG ' 'd# ' ! 105 25.0 1.11

W- 9lopsaaoEHT..On IB MASSE; W-13 2.2 1.90

3 0 P1B CTOS 1-14 7.6 1.68SlOp IK SLAG ...... • < : -■

W-12 15.2 1.55

61 mmmmmrnmm'

20 EEB GEKTOtt IK MASSE; 67 6.8 2.0926 EBB GEKS 69 14.0 1.67Si02 IB SLAG

t

: 65 m.i 1.36

iW-4

SO PEB OBKTOtt IB MASSE; 95 6.4 2.52So per m m 96 10.8 2.01S102 IK SLAB

89 22.4 1.49

7720 m osss:On IH MASSB; 83 5,0 2.6236 EBB GEKS 86 12.0 1.98Si02 IN SLAG

81 22.0 1.42

(a) The dlatribution ratio Is defined as the ratio of the per bent ft manganese In slag to the per cent of manganese In matte.

2S

TABLE 4 COlf.

MELT 10. PER CENT Mn IS MATTE DI8TBIB0TI0S RATIO" 1 ' * r - , • . . . . • - 1 -.■# * ’ ' " ’ ' - . . . . . . . . . . . . ■ * ■ — * * • •

SOPEROEKT 54 1.8 8.22On IS MATTE;

58 3.8 2.8225 mSL CENT8i02 IN SLAG 66 6.8 2.14

60 8.9 1.98' T : ' ^ - 48 ' 10.6 2.08

22 - T —

• — ■' - - . - ' - - ■ - ■ *■ ■ . . . " ' • ' ' • ► ^ 0 % ) ■ ■ 3.40 . . . .

80 EBB OBT 30 2.5 3.78Ott IS MATTE;

52 4.2 3.5080 IBB O U T — — - . . . . . . . ■ ■ . . . . . . - ■ —

3i02 IN SLAG 36 6.2 3.03■ g g 8.0 ’ ' 2.65

42 11.9 2.00

84 „ m 11. , m

30. EBB CENTCn IS MATTE; 86 1.5 3.3835 EBB CENT 88 4.3 5.84810* IS SLAG

78 11.6 2.13

10040 EBB OUTCu IS MATTE; 108 1.0 4.9080 EBB CENT 110 8.6 3.768IO2 IS SLiS

102 7.4 2.84

s:WL-v:

MELT KO. PER GBED Mn IS MATTE DISTRIBUTION RATIO i

TABLE 4 - DISfHIBOTIOH RATIOS (COEULUDED) . v

13 • — ■ • ■NOB-AGGLOMERATED 19 v-' :';3.1 ■ ; 2.57

i 20 PER CENT 39 §•#Cu IN MATTE;

27 . V. ’ 7a. : 2.2130 PER CENTSiOg IN SLAG ■ dl »•» 1.95

33 1S.« 1.5349 15.4 i.52

1©6 11.3 l*M1S

(a) 94 11.6 1.83

i $e) Series In which the ratio of matte and slag weight# were varied

28

•aeh case 20 per cent copper In the matte, are shown in Fig. 8.Similar trends are ahovn in Fig. 9 for three series analogous to those

in Fig. 8, hut uhioh contain SO instead of 20 per cent copper in the matte. It should he noted from Figa. 8 and 9 that the distribution ratio becomes smaller as the percentage of manganese in the matte Increases, and also that there is a tendency for the distribution ratio to decrease with a decrease of the silica content of the slag.

The trends of the distribution ratio are shown as functions of the copper content of the matte in Fig. 10, the silica content of the slag being 50 per cent for all melts. Two tendencies should be noted on this graph: first, that the distribution ratio becomes smaller as the per cent of copper in the matte is decreased, and second, that the elope of the curves,

■ ' ■ : • V - ' ■or, the rate of change of the distribution ratio to the percentage of man­ganese in the matte, become smaller as the per cent of copper in the matte is decreased.

A photograph of a apace model prepared to show in one graph all of the data of Figs. 8, 9, and 10 is presented in Fig. 11. This photograph shows four space curves, representing four concentrations (6, 10, 16, and 20 per cent) of manganese in the matte. Each of these space curves shows the re­lationship of the distribution ratio (02 coordinate) to the per cent of copper in the matte (OX coordinate), and the per cent of ailioa in the slag (OY coordinate). The three tendencies already noted, namely; the decrease of distribution ratio with (1) increase of manganese in the matte, (2) de­crease of copper in the matte, and (3) decrease of silica in the slag are shown.

Inasmuch as the original object of this experimental work was to de­termine the extent to which manganese would be substituted for iron in

29

oopper mattes, two graphs (Figs* 12 and 13) have been prepared to show this replacement for the series containing 30 per cent oopper in matte and 30 per cent silica in slag, which are the approximate copper and silica contents in usual commercial practice* The distribution ratio of mangan­ese and iron plotted against the per cent of manganese and iron in the matte, respectively, is shown in Fig. 12, although the curve for the dis­tribution ratio of manganese in this figure was given in Figs. 9 and 10.It is, however, extrapolated to a value of 22 per cent of manganese in the matte for Fig.12. This value was chosen as a limit for extrapolation

FIGURE 11 - PHOTO GRAPE OF SPACE MODEL

because in four other series, (the three series containing 20 per cent oopper in matte, and the series containing 6 per cent oopper in the matte,

and 30 per cent silica in the slag) the maximum manganese content of the

matte was approximately this value. This higier manganese content of the

matte was obtained in these four series as compared to the series under

to

30

FIG. 12

31

aonelderatlon because In each case all of the magnetite heA "been replaced by rhodoohroeite, whereas in the series under oonsldsration the end sub­stitution still oont&ined 4.3 grams of magnetite. With the minerals used in this work it is probable that 22 or 23 per cent manganese in the matte would be the highest obtainable figure, inasmuch as the sulphur needed in the formation of matte is limited, and any further addition of rhodoohro- slte to the charge would only increase the weight of the slag.

In addition to this extrapolated curve, a curve showing the iron dis­tribution ratio (obtained by dividing the per cent of iron in the slag by the per cent of iron in the matte) is plotted against a scale, per cent of iron in matte which is superimposed upon the horizontal scale, per cent of manganese in matte, for the manganese distribution curve, fhis iron dis­tribution curve is extrapolated to a value, 18 per cent iron in matte, com­parable to the extrapolated value of the manganese distribution curve.

She authors felt that the, curves of Fig. 12, plotted on semi-log paper,did not enable them to explain the trends of the distribution ratios; consequently Fig. 13 was constructed on ordinary graph paper from values obtained by interpolating from the curves on Fig. 12. The horizontal eo- ordinates of Fig. 13 are, at the top, the per cent of manganese in the . matte, and, en the bottom, the per cent of Iron in the matte. The values of the vertioal coordinates, percents of iron in the slag and per cent ofmanganese in slag, were obtained by multiplying the per cent of manganese

■ . \ \ , ■ . ; . - . ' . ■ . . • . ■or iron in the matte by the oorrosponding distribution ratio.

It should be noted in Fig. 13 that in this series the per cent of man­ganese in the slag reaches a maximum of 25 per cent at approximately IS per oeat manganese in the matte. This maximum value of the per cent of mangan­ese in the slag was characteristic of the data of all the series made and analysed.

. I P2

R C2HT I

RON

IN S

LAG

32

FIG. 13

g&R dBH7 Iu

A3IOAirESE II

SLAG

33

manna

Owing to tha faot that tl» syatteetio melts made in this experimental ierestigation were made in Bometiiat differwtt manner than smelter eharges would he male in oommeroial practice, some oonoern was felt as to the sig­nificance of the data obtained. Consequently s systematic study was made of the effect of these deviations from standard practice.Effect of Agglomeration ' ; - . ■ _ '" .. . _ .. ' ■

Perhaps the greatest difference between commercial practice and the method need for making melts in this experimental work was the practice ef agglomerating the charge with a half gram of dextrin. In order to deter­mine the effect of this agglomerating, one series (20 per cent copper in matte and 50 per cent ell lea in slag) was repeated without agglomeratingthe eharges. The results of the effect of agglomerating are shown in Pig.14. It should be noted from, this graph that there is some change, al­though hardly appreciable, in the distribution ratios when the charges are agglomerated: these effects of agglomeration are to slightly increase the distribution ratio and decrease the slope ef the curve. However, con­sidering the erratic values obtained and the difficulty of obtaining melts analysing within the copper and allies tolerances without agglomeration, the authors feel that the data obtained from the melts which had beenagglomerated previous to charging were on the whole more accurate thanthe data obtained from the nom-agglemrated melt#.Effect of Ghangee in Weights of Matte ind Slag

In order to determine whether the distribution of manganese betweenthe slag and matte was a tnsdistribution ratio er whether it was affected V v ;■ v;.-: v ;®y Pangea in the relative amounts of matte and slag, three melts were

made, each containing approximately the same percentage of manganese in

DISTRIBUTION

RATI

O

3caH

EFFECT OF AG<3LO"GRATXO!'t A l l IJEelte

2

the matte, hut varying ta the ratio ef wights of slag to matte from l/3 te S/l. The ejqperimental data from this study are given In table 6. The data ladioate that the differenoe of distrlhatiom ratio is almost negli- gible. It is, in fact, nearly within the experimental error. Therefore for all intents and purposes, the dletrlhutlon of manganese between the slag and matte may be oonaidered a true distribution ratio.

38-

TABLE 6 - EFFECT Of VAHIIHO TEE BATIO OF MAT® AID SLAfi 1EIGHT3

MELT • BO.

M A I® W E IG H ,8 a m

SLAG miGET,asm

PER CEHT Mn IB MAT®

D IS iaiB O T IO BRATIO

48 6.8 19.0 11.9 1.00106 14.7 18.8 11.8 1.9694 19.7 6.0 11.6 1.83

Effect of Fusion Temperature . . ■ •• ' : • ' -Inasmuch as it is wnwivehle #at the manganese distribution ratio

could be different at different fusion temperatures, the fusion tw^era- turee of one series (the agglomerated series of Fig. 14) were varied in order to determine that effect teeperature had upon the distribution ratio. Melts Bos. 93 and 95 were settled 10 mimatee at 1300 degrees 0. and melt Eo« 87 (as plotted on Fig. 14, the point to the extreme right) was settle at 1200 degrees 0. An inspection of this curve shows that all of the values fall on a straight line, ami so it was concluded that the fusion temperature had no appreciable effect upon the distribution ratio.Effect of Impurities /... : . : ' v

As previously stated, minerals were used for the charge of the syn­thetic melts in order to simulate the hypothetical commerela! praotioe... it •o happened that some of the minerals used carried appreciable percentages

m

of pltoaphoras and alumina, and at one time concern was felt as to the effect that these constituents might have upon the manganese distribution ratio • Work done by Mr. A* H. Boberaon in Which a number ©f melts were made using very pure minerals, proved that the presence of these materials had no appreciable effect upon the manganese distribution ratio.Summary and Generalisations '

ill of the experimental work herein described indicates that the efficiency of substituting manganese for iron in copper mattes is low when the substitution is effected by means of a crucible fusion.

She distribution ratio, defined in this paper as the per cent of man­ganese in slag to per cent manganese in matte, as determined in the exper­imental work, was in no ease less than one. If this optimum ratio pre­vailed in practice, even assuming that the slag produced was equal in weight to the matte, for each pound of manganese substituted for iron inthe matte one pound of manganese would he lost in the slag.

2/She original contention that the reactions■ , •MnO f. BBS Kn3 + FeO,

mould go to completion has been proved erronious, under the conditions of this experimental work. Assuming the mount of oxide in the matte azfd sul­phide in the slag to be negligible (not entirely true, but accurate within

- 5 per cent) it is possible to calculate from the iron and manganese dis­tribution ratios that the reaction as represented above is actually an equilibrium and varies from 20 to 40 per cent eeaplete as read from leftte right depending upon other factors, namely the concentration of copper

■ ̂ " ' ' ' - ,

and manganese in the matte and silica in the slag.

7/ See page 11 .