CA1156051A - Method for treating sulfide raw materials - Google Patents

Abstract

A METHOD FOR TREATING SULFIDE RAW MATERIALS

A b s t r a c t The present invention relates to the field of non-fer-rous metallurgy and more specifically to methods for treating sulfide raw materials.
The said method comprises an autogenous smelting of the said raw materials with flux additions in a blast furnace, where a quartz layer 0.3 to 1.5 m high is provided immediately above the tuyeres of the furnace. The smelting process is con-ducted with oxygen-enriched air blowing with an oxygen consump-tion of 300 to 400 m3/tonne of sulfide material. The said smelt-ing method produces matte suitable for subsequent converting, elemental sulfur, and off-gases containing 8 to 25% SO2.
The said method can be applied for copper and copper--nickel production.

Description

1~5~0~1 A METHOD ~R TREATING SULFIDE RAW M~rERIAl.S

The fleld of ~echnology The present ~nYentien relates to the field of non-ferrous metallurgy and more speci~ically to method for treating sul~i-de raw materials.
The treat~ent o~ sulfide raw material~ is aimed at reco-very of metals and sulIur therefrom. Sul~ide raw materials include ores, for in~tance, copper~ copper-zinc, copper-nickel ores, concentrates and intermedlate products of ore beneficia-tion.

Background of the in~ention Treatment of sul~ide raw materials implie~ direct reco-very o~ ~etal therefrom or recovery o~ metal into a matte that is then converted for product~on of metal or inriched ~ulfide phase (e.g. copper-and-nickel converter matte produced by smelt-ing copper-nickel ra~ ma~erials) from which metals are reco~er-ed by subsequent proce~sing. ~irect recovery o~ metal, in parti-cular ¢opper~ ~rom sulfide raw Material~ i8 accomplished in a ~in~le uni~ or in a number of unit3 ~or continuou~ smelt~n~
prQce~ ln 3erie~, ~he kno~n method~ for con~inuou~ smelting have, however~ not till now come ta an exten~ive commercial u~e.
In the practice o~ non~errou~ extractive metall~rgy, methods ~re primaril~ in use implying the recoYery o~ me~al8 in the form Q~ matte, ~rom which metal~ are produced by a ~ubsequen~
proce~sin~.

- 2 -115~0~1 The ~nown ~ethods for treatin~ sulfide raw materials to produce matt~ include smel-ting of raw material~ in bla~t 7 re-verb~ratory, electric and flash smslti~g furnace~.
The blast furnace smelting requires a char~ con~aining raw materi~l and flux, the use o* a ca:rbonaceou3 ~uel7 mainly coke, and oxygen-containin~ ga~ blowingO All the kno~n ~ethods for smelt~ng sul~ide ra~ material~ in blast furnaces involve the use of c~rbonaceous fuel.
Dep~nding on the compo~itions of the initial raw mat~rial and of the produced ~roduct~, the methocls for sulfide raw mate-rial treatment in bla~t furnace~ are divided into pure p~rite ~meltingt partial pyrite smelting and copper-and-sulfur smelt-ing (Orkla process).
To treat massive p~ritic copper ores (i.e. or~s with a low ga~gue content) containing at least 32% sulfur, pure py-rite smelti-ng was used. This method involved ~melting o~ char-ge, co~sisting of ore with flux (quartz a~d limestone) additions and up to 3~ wt~ of coke, in a blast furnace with a~ open th~oat and with air blowing at a rate of about 1,000 to 1,200 m3/tonne of ore. The oxygen consumption amounts to about 210 to 250 m3~
/tonne of ore. During smelting, copper is recovered into matte, ~ulfur pan~es into off-ga~ Smirnov V.I. Met~llu.r~y o~ copper and nic~el, Sv~rdlovsk-Moscow, M~tallur~izda~, lg501 p, 176~255?
and in particular pO lB8, 195, 200, 252; Peter~ E.D. ~he Practi-~e o~ Copper 5mel~ing, New York, ~acGraw-Hill Book Company~ 1911 p. ~04-242, and in part~cular p. 236).
~ rhi~ m~thod provided a high rate o~ desul~uriza~ion ~up to 95~0) and a hi~h ratio o~ conc~ntration (up to 20-~5:1).

_ 3 _ The concentration ratlo i~ the ralationship between the copper conte~t in matte and the copper content in initial raw mate-rial. Howeverl the pure pyrite smelting process ~as difficult to control because o~ a unstable hea~ balance and because of a long time required for the charge to pass through -the fur-nace. Furthermore, fuel required for the process operation was expensive coke in an amount of up to 2~5-3% of the total charge weight. Some attempts wer~ made to implement the pure pyrite smelting without coke additions, i.e. autoeenou~lyt but no po-sitive results were attained if the process had to be conduct-ed for a longer (several day~) period (Sticht X.S. ~ber da~
~esen des Pyrit-Sch~melzverfahrens, Halle, ~ilhelm Knapp, Metal-lurgie, May 1906, N 9, S. 269). It should be noted that during the pure pyrite smelting process sulfur was normall~ lost with off-gase~ and had to be emitted into the atmosphere, whereby the environment was contaminated. ~his process was in common use at the beginning of the 20th century, but later a change over to partial pyrite smelting was done due to a gradual exhaustion of mas~ive copper pyrite ore deposits.
~ he partial pyrite smelting i~ conducted on copper pyrite ore and/or lump-size concentrates, containing less than 32%
sulfur. This method implie~ smelting of a charge that consist~
of ore and~or conc~ntrates wi~h ~lux addition~ and o~ up to 1~.5% wt, carbonaeeous fuel, usuall~ coke, ~ a bla~t fur~ace with an open or sealed throat and an ~lr or oxygen-~nriched blowing~
?he u~e of other carbonaceous ruel~, e.g~ pulverized coal, fuel oil, or na~ural ga~ introduced through the tuyere~ or the ~ 1 5 ~
use of them in -the form of combustion products fed abo~e the tuyeres, allows one to reduce the consumptio~ of expensive co-ke to a certain extent, but doe~ not completely elimina~e its use.
The air blo~ rate amount~ up to 1,500 m3/tonne of sulfide raw material or even rnore~ while the oxygen-enriched blow rate is about 775 to 1,215 m3/tonne o~ sulfide material. The actual oxygen requirementi for smeltlng one tonne of sulfide raw mate-rlal, taking into account oxygen needed Ior coke combustion~
does not exceed 150 m3. During smeltir~, copper i~ recovered into matte, sulfur tran~3fers into off-gas (Smirno~ V.I. Metal-lurgy of Copper and Nickel7 Sverdlovsk-~oskow, Metallurgizdat~
1950, p. 199-2119 and in par-ticular p. 200 a. 252; IJebedev ~.I.
et al., Copper blast ~melting with ox~gen-enriched blowing, "~svetnyey metally", 1961, N 3, p. 32-39).
The partial pyrite smelting process provide~ a lower, a3 compared to the pure pyrite smelting ? extent of desulfuriza-tion (up to 79~0), a lower ratio of concentration (up to 4 5:1) and a low S02 content (2 to 5%) o~ the off-gas, which makeQ i~
difficult to recovsr sulfur therefrom. Furthermore, thi~ met-hod involves a higher consumption of expensive and ~.hort-o~--supply coke a~ a heat source. The use of oxyge~enriched blow-in~ allow~ to cut down the coke .r~uirements, but by no ~ore than 30%~
l'h~ pa~t-lfll p~r~te ~melting process :L~ o applled for treatlng copper-nlckel sulfide or~ and/or con~en~rate~ o~ p~r-rhotit~ t~pe pro~iding a de~ulfurization rate o~ up to 50 to 65~. Whe~ ~mel~ing ~uch ~ raw mate~ial a~d u~ing ox~gen-enriched ~ 156~51 blowing, the co~e consumption decrea~e~, but by no more than 40%~ ~Ind i8 maintained at about 5.8% of the charge weight (Bi3-wa~ A., Davenport WD ExkractiYe li~etallurgy of Copper, Oxford, Pergamon Press, 1976~ p. 100-109).
During 1930s the so-called copp~r-and sulfur process (Orkla met~od) wa~ developed for smelting sulfide raw materials.
T~is method is used to treat copper pyrite ores with a sulfur conten~ of 40 to 45~. This process involves smelting a charge~
con~3isting of ore and f.luxe~ with addition of solid carbona-c~ou~ ma~erial, e.g~ cok~, in an amount of 10% o~ the total charga weight, in a blast furnae with a sealed throat. '~h~
smelting process is accomplished ~ith air blowi~g at a rate of up to 1,000 m3/tonne of ore, and the oxygen consumption here-with amount~ to 210 m3/tonne of ore. The actual oxygén requi-rement is e~en lower becallse some ox~gen of the blow air is used for combustion of a part o~ coke that plays a role of fuel in the smelting proces~ Another part o~ coke burns in the midd-le zone of the furnace to pro~ide reduction of S02 formed as a result of ~eS oxjdation in the bottom zone of the furnace. The products of the ~melting proces~ are matte, slag, elemental sul-~ur and sulfur-bearing gases, from which additional elemental sulfur is recovered in the presence of a cataly~t (US Patent 1,860,5~5, Cl. 23-226, ~ay 31, 1932).
~ hi8 mothod p.rov:ide~ a ~3uffi.c:iantl~y high sul.~ur recove~y in kho ~or~ o:~ elemen~al sulfur from sulfide m~berial~, which i~ a ~ub~banti~l advant~ge in comparison to othex me~hod~. On the other hand, thi~ method show~ a low desul:furization rate ~ t 5605 1 (up to 85%) and a low rate of cvncentration (up to 5.5:1). As a result, -treatment of ores, containing9 for example, 2.5% cop-per, yields low-grade matte~, containing 8 tc 107o a~d maximum 14 to 15~o copper. Prior to converting, such matte~ should be subjected to additional treatment in a upgrading smelting fur~
nace (concentration smelting) and this increases the cost of raw material processing. This proces~ also require~ the use of coke, not only as a reductant for recove~y o~ sulfur from S02, but also a~ fuel. ~urthermore, this process i~ hard to control, because it takes a long time for the charge to pass throu~h the furnace. Sulur-bearing gases~ after a catalytic treatment, have to be discharged into the atmosphere because sul*ur i5 difficult to recover therefrom.

Objective of the invention The main objectiv~ o~` the said invention ~s to impro~e the sulfide raw material~ treatment in bla~t ~urnaces, and to reduce the costs o~ raw material processing, and to increase the sulfur reco~ery therefrom~

Summary of the invention ~ he ob~ecti~e o~ the said inYention was attalned by using a method :~or treating ~ulfide raw materials in a bla~t furnace~
the said met~od comprising the smelting of a ch~rge, con~l~t-lng of metal-bearing raw material and ~luxe~ with oxygen-co~-taining g~ blowing to produce matte, ~lag, elemental sul~ur 0 ~ 1 and sulfllr-bearing off-~a~. The part~cular feature oP the said method i8 th~t the charge smelting is conducted autogenou~s~y in a furnace with a quartz la~er 0.3 to 1.5 m high lmmediately abo-ve the tuyeres, which allows to maintain a desired amount o~
charge to be ~melted a3 per 1 m2 of the furnace cro~s sectio~
vlithin the tuyere zone and per a unit of time and to ensure a sufficiently complete oxydation of iron sulfide~ that form~ as a result of higher sulfides contained i.~ the initial raw mate-rial, by the oxygen supplied with oxygen-enriched air blowing with an o~ygen consurnptiion rate o~ 300 to 400 m3/tonne of sul-~ide raw material.
As the sulfide raw material treatment is accomplished autogenously, i.e. without use of coke or any other carbonace-ous fuel, the cost of the process is substantially lower.
This is a major merit o~ the said invention.
The said method allows one to produce high-grade matte~
in a ~ingle step and to increase the sulfur recovery from the raw material. .
The advantages o~ the said invention include al~o its applicabilit~ to a ~ido variety o~ sulfide raw materials, for example, copper, copper-zinc, and copper-nickel orec3; lump-size copper, pyrite, and pyrrhotite concentrates, and intermediate produc~3. rrhe merlt3 af the said lnvention will be illu~trated th~ ~oll~win~ d~tai.led description.

Detail~d descriptlon ~ the inv~tion rrh~ ~aid method for tr~ating ~ulfide raw material~ com-pri3e~ smelting o~~a charg~, con~i~ting o~ raw matorial and 1 1~6~Sl fluxes in a bla~t furnace, where a quartz layer 0.3 ko 1.5 m high ~ provided immediately above the tu~eres. q'hrough the tuyeres, oxygen-enriched air is supplied into the furn~ce. The oxygen requirement amount~ to 300 to 400 m3/tonne of sulfide raw material.
When testing the smelting process with oxygen-enriched air blowing, it wa~ found that the consumption of coke a~ fuel can be reduced. Complete elimination o~ the use of coke as fuel, however, can be ach~eved, a~ i~ was ~ound~ only when the mention-cd feature~ of the said invention, i,e. the above hei~ht o~ the rquartz layer and the specified oxygen requirement, are proviAed.
The said method for processing sulfide raw material~ i~ ac-complished in a blast furnace of a common design with a her~eti-cally sealed throat used for non-ferrous metal production. The charge consisting of sulfide ore and/or lump-slze sul~ide mate-rials (e,q. briquetted concentrate) and fluxes (quartz and li-mestone) is fsd into the furnaca through a ch~rging device en suring hermeticity~ Individual component~ o~ the char~e shall be in the form of lump~, prefer,ably of not too large a size not more than 100-120 mm. To provide the required gascous im-permeability of the charge within the furnace the share of the frac-tio~ ~ize minu~ 20 mm should not exceed 5 to 10%. It i~ pre-~er~able to rni~ cQMponents of t;he eharge prior to it~ lo~di~g into the ~urnace, but it i~ al~o po~sible bo inbroduce th~m l~to the '~UI~aCe by individu~l layers.
'rhe charge ~meltin~ i~ conduc~ed in ~ ~u~nace where a quartæ la~er 0.3 to 1.5 m hi~h ~i~ provided ~mmediately above the tuyeres. The te.rm "quartz layer" should be understood as a bed consisting primarily of quartz, as well a~ of a small amount of limestone, slag, and ~ulfides. Initlally, the fur-nace can be put into operation by any of the common methods, and, when the furnace is about to reach the normal smelting conditions~ a quartz layex of the indicated height is provided by feeding and smel-ting a charge contai~ing an excess amount o~ guartx in cornparison to the calculatled quartz content in the normal working chargeO The total amouIlt o~ quartz to be int:roduced intio the furnace, when it i~3 nearing the rlormal smelting conditions to provide a quartz layer o~ a specified height, is calculated on the basis of the cross section area and the bulk weight of quartz. The height of the quartz layer should be within a range of 0.3 to 1~5 m. These values are cho-se~ because, when the quartz layer is less than 0.3 m, the ratio of concentratio~ decreases below the required level, and when ths quartz layer is more than 1.5 m thick, the norrnal process operation is disturbed.
In accordance with the sald invention the sulfide material smelt~ng is conducted with oxygen-enriched air blowi~g introdu-ced into the furnace through tuyeres. ~he blow rats is 900 to 1,200 m3/tonne of sulfide raw material. The oxygen content in the blow i8 25 to 45%. With an o~en consumption o~ le~ than 300 r~3~torme of sulride raw materlal low grade matte i8 produ-ced~ ~nd wh~n ~he oxygen consump~ion ls lncrea~ed to over 400 m3/to~ne vf 9ul~ide ra~ material, there would b~ an axc~ss o~
oxygen that i~ not cle~ira~l~, because at ~he higher lavel~ ~f 13L5605~
the furnace it oxydiæes elemental sulfur, formed as a result of hlgher sulfide dissociation, whereby the normal process conditions are d~sturbed~ The recovery of elemental ~ul*ur i~
therefore lower.
Liquid products obtained as a result of the smelting pro-ces~ are separated in a forehearth into matte and slag. The off-gases leaving the furnace are sub~ected to dust collection and transferred ;nto a condenser for the recover~ of elemental sulfur. After the ~e-paration of elemental sulfllr the off-gases can be utllized for sulfuric acid manufacture or for additional recovery of elemental sulfur by the means of S02 reduction. The desulfurization rate reaches 95~ during the smelting. The reco-very of elemental sulfur~ when smelting -pyritic oreAs amounts up to 45%. Using the said method a ratio of concentratlon of 30:1 can be achieved. ~his means that e~en smelting low-grade ores (for example, copper ores w~th a copper content of 1.5 to 2%) can produce high-grade matte (25 to 40% copper) that does not require additional smelting prior to the converting, ln o~her words, the produced matte is tra~sferred directl~ for further processing in converters. Slags obtained as a resul~ of treat ing sulfids raw materials by the said method are normally con~
sidered to be discard slags. A characteri~tic feature of pro-duced ~lag~ i~ the ~act th~t they have practicall~ ~o or ve~
low (up t~ 5%~ co~tent of magnetite. When qmelting copp~r zlnc materialt th~ obtained sl~g can be used :~or the recovery of æinc the~e-rrom, ~or example, b~ slag~uming metbod~ Slag~ ob~
t~ined whe~ ~meltin~ copper-nlckel material can be ~ub~ect~d to ~laK-clea~ing, Xor e~ample, i~ an ~lectric furna~e.

115~
Hi~h pxoce~ values could be attained by virtue of the ox~ygen-enriched ai:r blowing with oxygen consumption within the ~pecifie~ range. The quartz layer o~ an appropriate height prevents an excessive increase of the smelting productivity and thereby it contribute~ to the higher ratio of concentra-tion due to the intensification of the iron sulfide oxidation by oxygen in the air blow in the presence of quartz.
By virtue of the nature o~ the said in~ention malfunctions of the smeltin~ process can be readily corrected by controll-ing -the ox~gen consumption which should be maintained withi~
the ~L)ecified range.
In one o~ the embodiment~ of the said invention a carbona-ceous reductant, e.g. natural gas~ coke, fuel oil, or another suitable red~ tant, is introduced into the blast fur~ace to improve the elemental sulfur recovery. In the reductio~ zone of the furnace, S02 formed in the oxidizing zone a~ a resul~ o~
iron sulfide oxidation on the quartz layer is reduced to ele-oDfS~ CC~
ental sulfur. As it has been stated, there i8 ~ clLc;~L~nooxygen in the zone where reductant is introduced, because oxygen ha~ been consumed in the oxidat~on zone. If n~tural ga~ is used a~ reducta~t, its consumption i8 60 to 70 m3/tonne of sulflde raw material and it should be supplied into thc furnace at a ra-te o~ 36 to 73 m/~ec. Gas is supplied through noæzles located above th~ tuyeres into a zone where practi~all~ no oxygen i~
pre~nt~ becauso it ha~ be~n completely ~pent to react wi-th lro~ ~ul~lde~ ~here~or~, combu~tion o~ natur~l ~as in the ~ur-n~ce cannot ta~e place and the proce~ r~mflln3 autogenou~, The lL 15~5 1 rnentioned gas injection rate range is determined by the fact that a-t rates lower than 36 m/sec the recovery o~ elemental sulfur decreases to some extent, because of a nonunlform dis-tribution of gas throughout the furnace. At rates over 73 m/sec, the recovery of elernental sulfur alsv decreases because some gas passes through the -furnace unreacted. UIhen smelting pyri-raw material and using natural gas as reductant, the recovery of sulfur in the e~Inental form, amounts to 57 to 59%.
'~/h¢n coke, preferably of a si%e -25 ~10 mm, is u~ed a~
rcductant~ its consumption i~ abollt 6-7~o of the total charge welght. Coke is fed in-to the furnace together with the charge.
~n this case the process is as well autogenous, because the amount of coke is equal to the stoichiometric amount required only for the S02 reduction. The recovery of sulfur in the ele-mental ~orm, u!hen ~melting pyritic ra~ materials~ i9 65 to 67%
be The said method can used for processing various types of sulfide materials, e.g. copper pyrite ores, copper-nickel pyr-rhotite ores, copper, pyrite and pyrrhotite concentrates, cop-per-zinc ores and middlings. On the other hand, the conventio-nal blast furnace smelting proce~ses are not applicable to all type~ o~ sul~ide materials. Among other thing~, ore~ containing over 3% %n cannot be processed by -th~ copper-and sul~ux smelt~
ln~ process. ~o~eover, the said inv~ntlon can be aoplied to low-grade p~ritic material~ rO~ q~.ample, pyrite concentrates, containin~ pr~ciou~ metals. It pr~vides h~rewith a su~icie~tl~
hi~h recovery o~ metal~ into matte. At present lo~grade pyri-11 ~605 I

tic raw materials are used for sulfuric acid manufacture; and the precious metal~ con-tained report with calcines and are not recovered in most case~, because of high processing costs.
A comparison o~ the said sul~ide material smelting method with the conventional copper-and-sulfur smelting~ that also provides reco~ery oP metal into matte and recover~ of eleme~-tal sulfur, shows that th~ said method is commerclally supe-rior because it h~ the f'ollowing advanta~e~. 'rh~ ~aid process i5 autogenous~ i.e. -lt does not i,nvolve the u~e of carbonaceous fuel. It allows to save 25 to 30 kg of coke per 1 tonne o~ sul-fide material treated. The ~aid method allows to treat low--grade ores (e.g., ores containing 1.5 to 2% Cu) and produce suf~iciently high-grade mattes (25 to 40% Cu) that can be used immed~ tely for converting and thus upgrading smelting is elimi-nated. The total sulfur recovery from pyritic raw material~
treated by the said method is 85 to 90% or more, and that from pyrrhotlte materials i8 70 to 75% or more. A considerable part of sulfur ls recovexed a~ elemental sulfur. The off-gases after elemental sul~ur collection contain -~rom 8 to ~5% S02 and can be used for sulfuric acid m'anufacture, Thus, sul~ur-bearing gas emls~io~ into the atmosphere ara practically eliminated. ~his makes the sflid method advanta~eou~ ~rom the point o~ view o~
the envi~onment protec-tion as w~ll.
Fro~ the mentionecl ~ac-ts it ~ollows that tho said inve~-tion allow~ one to substantlal'ly recluce the co~ts o~ ~ulfid~
material processing duo to th~ eli~ination of :~uel requirements and up~ra.ding ~meltin6: it en~3ure~ a high ~ul~ur recover ~rom -- ~4 --l ~6as ~
~u1fide rnatorial~ and eliminates deleterious emisslon~ into th~
atmosphere.
~ `or better understanding of the said in~entlon ~ome example~
of specific embodiment~ are given.
Example 1 The smelting of a charge was conducted in a blast furnace, having a capacit~ of 70 to 100 tonnes of charge per da~, with a hermetically sealed throat, a quart~ layer 0.45 to 0.55 m high was provided immediately above the~ tuyeres. 'rhe charge had the following compositio~ copper pyrite ore (1.93%
Cu, 41.5% Fe, 46.1% S) 65.8; quartz 23.7; llmestone 10.5. The quartz ~ yer was provided, when the furnace was about to reach the normal working conditions by feeding charge higher in quartz than the calculated charge composition. ~he smelting process was conducted blowing air enriched to 28~o oxygen. The blow rate was about 1,100 m3/tonne o~ ore, the oxygen consump-tion herewith was about 300 m3/tonne of ore. ~iquid smelting products were separated into matte and slag in a forehearth.
The sulfur-bearing off~gas at a temperature of 380 to 440C
wa~ transferred, aft0r cleaning, into a condens~r for elemental sulfur separat~on. The recovery of sulfur in the elemental form wa~ 41.7%. The desul~urization rate was 90.5%. The off-gas after ~ulur condensation contained ~%): 22.4 S02, 0.15 H2S, 0.16 COS, 5.0 C02, 0.2 C0 and -9 2~ the balance wa~ nytro~en. Such a ga~
could be utiliz~d *or 3ulfuric acid manufac~ure or for additio~
n~l ~lem~ntal sulfur recov~ by reduction. ~ke ratio of con-contration wa~ 8:1. 'rhe produced mattfl8 conkained 22~8% CU

1 15~0~
and were subjected directly to converting for copper recove~y~
The proAuced slags contalned 0,24~ Cu and were discarged~ The silica, iron, and calci~n oxide content3 in sl~g~ wer~
35 40~ 34-39 6-9, respectively; there was practically no magne-tite in ths slags.
Example 2 Smelting of the charge, ~ ving the analysis as in Example 1, was conducted in a bl~t flurnace in the same manner as des-cribed in ~xample 1, but the quart~ layer height was 1 to 1~2 m;
the 33% oxygen-enriched air blow rate was 1,200 m3/tonne o~ ore, the oxygen consurnption herewith was about 400 m3~tonne of ore.
The following results were obtained. The desulfurization rate was 95%. The recovery of sulfur in the elemental form was about 43,5%. The off-gas had the following analysi~ (%): 23.3 S02, 0.21 H2S, 0.23 COS, 5.5 C02, 0.17 C0 a~d 0.8 2~ the balance was nytrogen. The ratio of concentration during smelting was 30.1:1, The produc,ed mattes contained 58.1% Cu. The produced slag~ contained 0.6% Cu. As for the rest o~ the slag constitu-ents, the slag analysis was similar to that in ~xample 1.
Thls example illustrates the extensive potential of the said process with respect to attaining a high ratio o~ concen-tration, _am~
Smelting o~ the charge, havin~ the analysis as in Exa~ple 1 t ~a~ oondllctecl in a blast furnac~ in the same manner, as des-cribed in Exarnple 1~ but the quartz layer height was 0.6 to 0.7 m; the 30% oxygen-enriched air blow rate wa~ abou~ llZ00 m3/

l ~560~ ~
/tonne of ore, the oxy~en concsumption herew-lth was about 360 m3/tonne of ore, to ~ncrease the sulfur recover~ in the el-em~n-tal form, natural gas wa~ introduced into the furnace for reduc-tion of S02 formed during the smeltin~ process, Natural ga~ wa3 fed into the ~urnace through nozzles located at a level of 0.6 m above the tuyeres, where ~ractically no oxygen was present. The natural gas injection rate ~as 45/sec and its consurnpt;on amount-ed to about 63 m3/tonne of ore. The following results were obtain-ed. The desulfurization rate was 92 8%. ~he sulfur recovery in the elelnental form was 57.7~0. The off-ga~ had the following analysi~ 11.6 S02, 1~33 H2S~ 1.4 COS, 9.5 C02" 1.6 C0, 1.0 2~ 0.76 H2 and 0.~'~ CH4; the balancs was nytrogen~ The ratio of concentration ~as 15.6:1. The prod,uced mattes contained 30.1% Cu. The copper content of produced slag~ was 0,33%. As for the rest of the slag constituents, the slag analysi~ was similar to that in Example 1.
Example 4 Smelting process was conducted in a blast furnace in the same rnanner a~ described in E~ample 3 with an exception that to improve the sulfur recovery in the elemental ~or;m, instead of natural ga~ coke wa~ added into the charge in an amount of 6.5~ of the total charge wei~ht~ The ~cllowing results were obtained. The desulfurization rate W~5 92~5~o~ The ~ulfur reco-ver~ in the olement~l form W9~ 65~n~ The o~f-~as h~d the fol-lowing an~ly~is (%~ 8.9 S02, ~31 H~SI 2.2 C~S? 13.3 C02, 1J7 ~0, 0~8 0~ the balanc~ wa8 n~trogen. ~ho ratio o~ concentr~-tion wa~ 15 4~ ho proauced matte~ conb~inod ?9.7% Cu~ '~he ~ 15~)S ~
copper content oî the pro(luced sLags was 0.31%~ As for the re~t of the slag consvtmtuents, the 31ag analysi~ was ~imilar to that in E~xample 1.
Exam 1~ le Smelting was conducted in a blast fu~nace of the same capa-city, as in Example 1. ~he initial raw material wa~ co~pe~zinc pyrite ore, containing 3.55% Cu, 7% Zn, 34.5% ~e and 43.7~ S~
Into the -fu~ace provided with a qu~rt~z layer 0.3 to 0.35 m high, charge of the followlng composition S~ copper-zinc ore 71.4, quartz 18.6, limestone 10, was fed. The smel-ting process was carried out with 32% oxygen-enriched air blowing. The blow rate wa~ 960 m3/tonne o~ ore, the oxygen consumption herewith was about 300 m3/tonne of ore. ~he following result3 were ob-tained. The desul~urization rate was 88%. The sulfur recovery in the elemental form was about 40%. The off-gas had the fol-lowing analysis (%): 25.2 S02, 0.1 H2S, 0.1 ~OS, 6.1 C02s 0.14 C0 and 7 2; the balance was nytrogen. ~he ratio of copper concentration was 6.8:1. The produced mattes contained 24.1 Cu and 3.5% Zn. The slags, containing 0.28% Cu and 5.5% Zn can be processed to recover zinc therefrom~ As ~or t;he rest o~
the slag con~tituents, the slag analysis was similflr to that in Examp le 1.
This example is an illustration of copper-~inc ore smelt-ing yieldin~; sati~factory results. And this is an additional fldvanta~e of the ~aid invention/ for such an ore car~ot be pro-cessed by th~ copper-and- sulfur smelting technique be~cause o~ bhe hi~h zlnc contenb~

1~ --0~1 Example 6 Smelting was conducted in a blast furnace o~ the same ca-pacity, as in E~ample 1. The initial raw material is low-grade pyrite ore, containing 0.5g~0 Cu, 45.4% ~e, 50.3~ S, 1.3 g~t ~v and 6.3 g/t Ag. Into the furnace with a quartz layer 0.65 to 0.75 m high, charge, contairiing 65.6% of the said ore, 24.3~
quartz and 10.1% limestone, was fed. The smelting process was conducted with 30 to 32% oxygen-enriched air blowing. The blow rate was 1,1~0 m3/tonne of oret the oxygen consumption here-with was 330 to 350 m3/to~ne of ore. The following results we-re obtained. The desul~urization rate was about 93%. ~he sul-:~ur recoverg in the elemental for~ amounted to about 45%, ~he o~f-gas had the following analysis (~0): 23.6 B02, 0.11 H2S, 0.23 COS, 6.8 C02, 0.27 C0 and 0.6 2; the balance was nytro-gen. The concentration rate was 14.2:1. The produced mattes contained 8.4% Cu~ 12 gJt Au, 75 g/t Ag. The copper, gold and sil~er recoverles into matte were 68.5, 79.6 and 85,7%, respec-tively. ~he copper content of the slags produced was less than 0.2%.
~ his example illustrates processing of low-grade pyrite raw material with a precious metals content. Under the same con-ditions, it is possible to proces~ lumpy (e.g. brique ~d or pelletized) pyrite concentrates.
xample 7 ~ Smelting wa~ carried out in a bla~t ~urnace o~ the same c~pacity, a~ in E,xa~ple 1. ~he initial raw material wa~ copper concentr~te~ oont~inin~ 16~3% CU7 6.2~ Zn, ~3~ Fe~ and 36.8%

~ 19 --115~
S. Prior to ~melting, the copper concentrat~ was form~d into lumps, for example, by the briquetting technlqu~ in a roller pres~ u~ing lignosulfonates ~wastes from the paper and pulp i~-dustries) as a binding agent~ Charge, containing 66.4% bri~
quetted copper concentrate, 24.7% quartz and 8.9% limestone, was fed into the furnace in which a guartz layer 0.9 to 1.1 m high had been provided The smelting process was conducted with 34% oxygen--enriched air blowing. 'rhe blow rate wa~ 900 m3/tonne of briquet-tes, the oxygen consumption herewith wa~
about 300 m3/tonne of briquette~ he following results were obtained. The desulfurization rate was 80~2%~ lrhe elemental 3ul~ur recovery was 24~7~o~ The off-~as had the following ana-lysi~ 16.9 S02, 0.13 ~2S, 0.18 COS, 4.4 C02, 0.15 C0 and -~ 2; the balance was nytrogen. The ratio of concentration was 3.7:1. The produced mattes contained 60.3% Cu and 1.5% Zn.
The slags produced contained 0,6% Cu and 5.9~0 Zn and could be processed to recover zinc therefrom, as well as to additional-ly recover some copper. As for the rest of the slag constituents~
the slag analysis waY similar to that in Example 1.

Smelting wa~ carried out in a blast fu~nace of the same ca-p~city, as in ~xample 1~ 'rhe sulfide raw material to be treated wa~ briqu~tted copper concentrate~ as in Exaraple 7. Charge o~
the ~ollowlng~ compo~ition: 63 9~ briquatte~ 26.5~ quartz and 9,G% lime~tone, was ~ed into the -~urn~ce wher~ a quartz layer 1,3 to 1~5 m hi~h had been provided. ~he smelting ~rocess wa~
conducted wi~h 35% ox~gen~enrlched air blowin~ The blow rate 1 156~5 ~
was 950 m3/tonne of briquettes~ the oxy~en consumption herewith wa~ about 330 m3/tonne of bxiquettes. ~he ~ollowing result3 were obtained. The desulfurization rate was 86.4~o~ The elemental sul~
fur recovery wa~ 25.2~. The off-gas had the following analysis (%): 17.8 S02, 0.15 H2S, 0.17 COS, 4.5 C02l 0.18 C0 and 0.7 0~, the balance was nitrogen. The ratio of concentration was 4.9:1.
The produced matte (white matte~ contained 79.5% Cu and 0~370 7,n. The produced slags contained 0.8% Cu and 5.6% Zn. A~ for the rest of the slag constituents, the slag analysis was simi-lar to that in Example 1. These slags could be processed to re-cover zinc and additional copper th~refrom.
Example ~
Smelti ng is carried out in a blast furnace o~ the same capacity, as in Example 1. The initial raw material was a pyr-rho~ite-type copper-nickel ore, containing 4.6% Cu, 4.3% Ni7 50~o ~e and 30.3% S. Charge,consisting of 67~5~o of the said ore, 24.3% quartz and 8.2yO limestone, was fed into the furnace, whe-re a ~uartz layer 1.1 to 1.3 m high had been provided. The smelt-ing process was conducted with 30 to 32~o oxygen-enriched air blowing. ~r~e blow rate wa~ 1,000 lD3/tonne of ore, the oxygen consumption herewith amounted to about 300 to 32 m3/tonne of ore.
The ~ollowin~ result~ were obtained. ~he de~ul~urization rate was 80.6%. The elemental sulfur recovery was about ll~o. The of~--ga~ had the following analysis t%): 16 S02, 0.1 ~2S~ 0.1 COS, 5 .1 co2 ~ o~ 1 ca and 5 2- The ra-tio of concentration ~or -the total mebal~ cont~n-t w~ 4074 1~ rrhR produc~d matte~ containRd 24.4% Cu and 17.8% Ni. ~he ~lags con~ained o.~a~ Cu and 0,28% Ni.

_ 21 --1 ~S~05 1 As for the re~t of the slag constituents, the slag analysi~ wa~
~imilar to that in Exa~ple 1, except Eor magnetite of which 4 to 5% was contained in the said slags. It i~ possible to carr~ out ~lag cleanin~, especially for nickel recover~. Thus~ the reduc-tion and sulfidiæation slag cleaning in an electric furnace en-sured a decrease in copper down to 0.1'7~ and in nickel down to 0.1% or less. Beside~ the ~lag cleaning proce~s can be accom-pli~hed at a significantly higher rate and with lower energy consumption than for slag cleaning following other autogenous proce~ses. This is attrihutable to the lower (not more than 5%) rnagnetite content in the obtained.
In ~xam,E)le~ ~ through 9~ the produced Mattes are transferr-ed directly to converting for further processing, For comparison, results of copper pyrite ore treatment by the copper-and-sul~ur smeltin~ process in accordance with US
Patent N 1,860,585 are given below. The charge consisted of 80.8% ore (containing 2.66% Cu, 38.5% ~e and 42,64% S), 11.5%
quartz. 2,7% limestone and 5% of recycled slag. The smelting of this cha~ge with a coke addition of lO~o of the total charge wei~ht was conducted in a blast ,furnace with a hermetically seal-ed throat at an air blow rate of 950 m3/torme of ore. The follow~
ing re~ult~ were obtained. The des~lfurization rate was 85.18%~
The ratio of concentration was 5.5:1. The mattes produced con-tained 14~6% Cu and were -treated in a ~imilar bla~t ~urnace with fl ~eal~d khroat to prOdUG~ l~ ttes with a copper cont,qnt of 40 to 50%, c)uitable -ror ~ub~;equent con~erting. ~he copper con~ent o~

- ~2 1 ~5~5 ~
~lags produced during ore s~elting wa~ 0.4%. A part o~ coke fed lnto the fl~rnace wa~ consumed for the S02 reduction, and another part passed down to the bottom o~ the :~urrlace and con-sumed oxygen supplled by air blowing, i.e. it behaved as fuel.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A method for processing metal-bearing sulfidic materials selected from the group consisting of ores, concentrates and intermediate products of ore beneficiation, said method comprising smelting of a charge consisting of said materials and fluxes with oxygen-containing gas blowing to produce matte, slag, elemental sulfur, and sulfur-bearing gases, the innovation of the said method is that the smelting is conducted autogenously in a blast furnace, where a quartz layer 0.3 to 1.5 m high is provided immediately above the tuyeres to give a means to maintain a desired amount of charge to be smelted per 1 m2 of the cross section area within the tuyere zone per unit of time and to provide a sufficiently complete oxidation of iron sulfide by the oxygen contained in the oxygen-enriched blow with an oxygen consumption of 300 to 400 m3/tonne of sulfide material.

2. The method as set forth in claim 1 wherein the oxygen content in the blow is 25 to 45%.

3. The method as set forth in claim 1 wherein a carbonaceous reductant is used to improve the recovery of sulfur in the elemental form.

4. The method as set forth in claim 3 wherein the reductant is natural gas introduced into the reduction zone of the furnace for consumption in the amount of 60 to 70 m3/
tonne of sulfide material with an injection velocity of 36 to 73 m3/sec.

5. The method as set forth in claim 3 wherein the reductant is coke introduced into the furnace with the charge in an amount of 6 to 7% of the total charge weight, so that this amount is sufficient only for reduction of SO2 to elemental sulfur.