CA1060217A

CA1060217A - Process for separating nickel, cobalt and copper

Info

Publication number: CA1060217A
Application number: CA242,750A
Authority: CA
Inventors: Sanai Nakabe
Original assignee: Sumitomo Metal Mining Co Ltd
Current assignee: Sumitomo Metal Mining Co Ltd
Priority date: 1975-01-23
Filing date: 1975-12-30
Publication date: 1979-08-14
Also published as: FR2298608A1; DE2601214B2; FR2298608B1; JPS5184721A; DE2601214A1; GB1537470A

Abstract

A PROCESS FOR SEPARATING NICKEL, COBALT AND COPPER

Abstract of the Invention:
This invention relates to a process for separating nickel, cobalt and copper wherein a mixture in molten state containing both nickel and cobalt or either of them and copper as an alloy and a matte or either of them is mixed in the presence of a matte, metallic iron and carbon to form a high carbon ferrous alloy and a matte in two separate phases and both nickel and cobalt or either of them is extracted predominantly as the high carbon ferrous alloy and copper is extracted predominantly as the matte.

Description

~060Zl~
Detailed Description of the Invention:
Nickel or cobalt is produced naturally often as an oxidized material rich in iron, such as manganese nodule or nickeliferous laterite; and cobalt is often wasted as slag along with iron in copper smelting or nickel smelting.
Therefore, alloy rich in metallic iron is often produced by reducing-smelting of the material in extracting the nickel and/or cobalt. The necessary production of a large amount of metallic iron by reducing of the oxidized iron, in spite of which being eliminated in the following steps, the need of a higher temperature in smelting because of the high melting temperature of the alloy than one in producing matte that causes consumption of an expensive heating energy such as electric power, and the low grade of the material, which is usually the case, impose a large burden of expense on unit amount of nickel and/or cobalt to be recovered, as is well-known. Especially, in extracting cobalt, production of alloy rich in iron is needed; for recovery of cobalt as matte is poor.
Nickel is produced naturally often associated with copper; and it remains in the crude copper, in smelting r of the copper ore, to be recovered commercially from the spent electrolyte in electrorefining of copper; but recovery of nickel by this process is expensive and of low yield.
A small amount of copper accompanying nickel can easily be eliminated for example in electrorefining of nickel; but a large amount of copper accompanying nickel can be eliminated only with a large expense. Therefore, many processes have been developed for separation of the copper;
but they are mostly expensive except where separation of nickel sulfide and copper sulfide through differential -1- ~ .
I

,: ' . :

i060217 flotation is successful.
Wasting of copper, nickel and/or cobalt as slag in copper smelting or nickel smelting is a problem, especially recently after flash smelting process is applied to sulfide ores in many cases. One of the largest reasons why recovery of values from such slag is difficult is that the slag contains a large amount of iron as magnetite.
Since solubility of magnetite in slag is limited, a large part of magnetite stays in slag as mushy suspension and encloses small globules of the matte so that recovery of matte by settling is hindered. Besides, magnetite has a higher oxidation potential than nickel oxide and cobalt oxide which are contained in the slag. Therefore, recovery of nickel and cobalt by reducing oxidized nickel and cobalt is not sufficient before magnetite is thoroughly reduced into ferrous oxide. Unfortunately, however, magnetite is difficult to reduce with the iron sulfide that is rich in matte at the temperature of commercial smelting operation and reduction of magnetite is a large problem in recovering the values from the slag.
Carbon has a large potential for reduction, thermodynamically speaking; and the reduction would proceed easily, for example, when a mixture of pulverized slag and coke breeze is heated; but the heating expense is not justified in recovering a small amount of values in the slag.
Reduction of magnetite in molten slag with carbon proceeds only under a strong super-heating of the slag, for the reaction is strongly endothermic; and this causes formation of a large amount of metallic iron with a result that this metallic iron functions as a secondary reductant for magnetite;
and the recovery is complete only after formation of metallic ;

, . ' , ' - 10602~7 iron in a far larger amount than what is needed from a point of view of equilibrium. This is the reality in extracting values from the molten slag, and its economy depends on how far the heating expense is saved for raising the temperature of the large amount of slag to the required point and for the reduction of oxidized iron into metal.
Manganese nodule contains nickel, cobalt and copper besides a large amount of manganese and iron and is an important natural resources in the futurei but it is not easy economically to recover manganese, nickel, cobalt and copper by separating them from iron and from each other by the said reasons.
Accordilngly, it is the general object of this invention to provide a process for extracting copper and one or both of nickel and cobalt separately from a mixture of the elements.
It is the main object of this invention to provide a process for treating molten product(s) from smelting of material(s) containing copper, nickel and/or cobalt in molten state to effect a rough separation of copper and the other element(s) so that further separation in refining steps is facilitated.
It is another object of this invention to ~rovide a process whereby the separation is effected economically by utilization of the metallic iron that is often produced in extracting nickel and/or cobalt from an oxidized material rlch in iron.
It is another object of this lnvention to provide a process for extracting nickel, cobalt and/or copper from manganese nodule, slag from copper smelting or nickel ~ 060217 smelting and other oxidized material rich in iron.
It is another object of this invention to provide a process for extracting cobalt as a byproduct of copper smelting and/or nickel smelting.
It is another object of this invention to provide a process for extracting nickel and cobalt separately from a mixture containing them.
The ordinary matte produced in copper smelting or nickel smelting is a quaternary mixture consisting of copper or nickel, iron, sulfur and oxygen; and it contains iron oxide, even magnetite, but practically no metallic iron. It does not separate into an alloy and a matte in molten state except in a high copper region. However, under more reducing conditions that is seldom in commercial operation, a matte can dissolve metallic iron to a considerable extent when little iron oxide is accompanied; and the matte is practically a ternary mixture of copper or nickel, iron and sulfur.
It is well-known that an alloy and a matte can co-exist in equilibrium in molten state in a large region of ternary system copper-iron-sulfur; but large amounts of copper are contained both in the alloy and the matte, and it is difficult to extract a major part of copper into matte based on this principle. No separation into alloy and matte takes place in the ternary systems nickel-iron-sulfur and copper-nickel-sulfur. A process for separating copper as matte and nickel or cobalt as alloy by addition of metallic silicon to the alloy is a process devised by the inventor and other and patented as the Japanese Patent No. 164,633;
but it is not fully economical because of the high price of metallic silicon.

, The inventor studied the equilibrium in molten state of quinary system nickel or cobalt, copper, iron, sulfur and carbon and found that a mixture of the system can be separated into two phases of a high carbon ferrous alloy and a matte and that a major part of niekel and/or cobalt is extracted as the alloy while that of copper as the matte. The present process is devised based on this prineiple.
Generally stated, the present process is a process for separating niekel, eobalt and eopper comprising mixing a mixture containing eopper and one or both of nickel and eobalt, that consists of alloy(s) and/or matte(s), in molten state in the presenee of a matte, metallie iron and earbon, that can be eombined as iron earbide, to form by the reaetion between the existing eomponents a high earbon ferrous alloy (having more than 0.5% by weight of carbon) containing a major part of the nickel and/or cobalt on one hand and a matte containing a major part of the copper on the other in two separate phases.
The present process will be explained more in detail as follows.
The mixture to be treated by the present process, hereafter to be named "mixture A", ean be an alloy or alloys, a matte or mattes or a mixture of more than one of them and eontains eopper and one or both of niekel and cobalt.
The alloy may eontain eopper besides niekel and/or eobalt, and the matte may eontain niekel and/or eobalt besides eopper. The alloy and/or the matte may also contain metallie iron which can stay dissolved in the alloy or matte in molten state. The mixture A ean be produeed by smelting ore or other material. The matte ~o be present in the ,,~,. , .. . .

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~060217 present process can contain one or more than one of copper sulfide, iron sulfide, nickel sulfide and cobalt sulfide as its main component; and it can be produced by the reaction between metal and elemental sulfur or sulfur compound which is supplied when the amount of sulfur is not enough to convert a major part of the copper into matte. The metallic iron to be present in the present process, including the one combined as iron carbide, must be more in weiaht than the total weight of nickel and cobalt in the "mixture A".
However, it is not always necessary to be presented as a separate phase, but may be presented as dissolved in the matte. If the amount of the metallic iron contained in the mixture A is insufficient for the reaction of the mixture even after adding the amount of the metallic iron produced by the equation of 2Cu + FeS = Cu2S + Fe, it will ke necessary to supplement a further amount of metallic iron or iron alloy. The carbon must be present in the resultant high carbon ferrous alloy at higher than 0.5% C, and its shortage as a component of the alloy in "mixture A" must be supplied as pig iron, as a high carbon ferrous alloy or by carburization of ferrous alloy or a matte containing metallic iron under its contact with solid carbon at high temperature. The separation of copper and nickel and/or cobalt is the more complete the higher the carbon content of the resultant high carbon ferrous alloy. It is needless to say that a temperature of about 1,150C or higher, at the temperature of which high carbon ferrous alloy melts, is required for the reaction.
Silicon is often contained in the alloy resulting from reducing smelting of oxidized material in extracting nickel and/or cobalt; and it is helpful, as has been explained, for the separation in the present process to produce a high carbon ferrous alloy containing some silicon.
The mixture can be mixed in the presence of matte, metallic iron and carbon in molten state, for example, simply by mixing the required components at room temperature followed by smelting. Smelting of ore can also be sufficient for mixing by the present process if the charge make-up is so controlled that a matte, metallic iron and carbon are present during the smelting operation as is shown in the following description. An alloy, or a matte in molten state can be percolated through a column of red hot lump coke for said mixing and carburization by the present process so long as the presence of the matte and the metallic iron is maintained. A molten matte may concurrently be percolated with the alloy, or an alloy containing metallic iron may ;-concurrently be percolated with the matte, if needed. Holding molten alloy and matte in a hearth with heating or pouring them into a hearth is usually sufficient for the mixing, so far as the presence of matte, metallic iron and carbon is maintained. Agitation with inserted green wood is also effective in this case. Alloy and matte separate into two layers quite rapidly, but the chemical reaction needed in the present process is also very rapid.
Thus copper contained in an alloy can mostly be recovered along with copper in a matte, if any treated, as the resulting matte, while nickel and/or cobalt in a matte can mostly be recovered along with nickel and/br cobalt in an alloy, if any treated, as the high carbon ferrous alloy resulting from the present process.
An alloy or a matte containing copper, iron, and at least one of nickel and cobalt can be treated by the present process after the following pretreatment. For example, a part of such alloy can be poured onto sulfur so that a required amount of matte is produced to constitute along with the rest of the alloy the mixture for the present process. For another example, metallic iron or an alloy containing metallic iron can be dissolved into such matte in molten state to produce a matte containing metallic iron as the mixture for the present process. Alternatively, the alloy and the matte can be brought together as the mixture for the present process. Alternatively again, an alloy can be produced by smelting the raw material with addition of sulfur-bearing material so that it contains sufficient amount of sulfur to form by the present process a matte which contains a major part of the copper in the alloy.
The amount of matte to be present in the present process in this case can be theoretically nothing at the start of the mixing while the matte appears at the end of the mixing.
Naturally, the amount of matte separating from a homogeneous alloy by carburization is limited; and a large amount of copper in an alloy must be separated in such a large amount of matte that a heterogeneous mixture consisting of the alloy and a matte is treated by the present process.
Similar situation applies to the amount of alloy or metallic iron needed in treating a matte containing a large amount of nickel and/or cobalt.
The present process can be performed in connection with smelting of ore containing copper, nickel, cobalt and/or iron. For example, an ore or its calcine containing copper, iron, and nickel partly as sulfides and partly as oxidized ~- ;
compounds is smelted with addition of a carbonaceous reductant so that an alloy and a matte are formed and extracted in molten state to be treated as the mixture by the present process.
Alternatively, a homogeneous mixture of an alloy or a matte can be produced in place of the alloy and the matte, depend-ing on the ratio copper to nickel plus cobalt. For another example, an ore containing copper, iron, and at least one of nickel and cobalt as oxidized compounds can be smelted with addition of a carbonaceous reductant so that an alloy containing copper, iron and at least one of nickel and cobalt is extracted in molten state to be treated as one of the components of the mixture by the present process.
Manganese nodule containing copper, iron, manganese, nickel and cobalt can be treated similarly, and copper, nickel and cobalt can be recovered from the resulting alloy; while manganese can be recovered from the resulting slag by well-known means. Alternatively, the alloy resulting from smelting manganese nodule can be treated by the present process so that is constitutes said mixture together with a nickel-copper matte produced, for example, from nickel-copper sulfide ore by smelting. In cases where a rich ore is smelted, a sufficient amount of carbon can be used to effect the carburization so that the present process is performed during smelting.
In treating a slag or oxidized ore containing one or both of nickel and cobalt, it may be smelted on a molten bath of copper matte or copper-nickel matte after dissolving metallic iron, or the bath may be agitated with addition of molten slag, to collect one or both of nickel and cobalt as alloy dissolved in matte, carburize the resulting mixture of alloy and matte, and separate one or both of nickel and cobalt as a high carbon ferrous alloy.
This manner of operation is called hereafter as "process A".

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The required temperature for the operation can be maintained in this case by addition of calcium carbide or ferro-silicon with agitation whereby it reacts with iron - oxide in the slag to form metallic iron required in the matte and generate a large amount of heat of reaction. The treated slag may repeatedly be discharged to renew the slag when the grade of the feed slag is low. The mother matte remaining after separating the high carbon ferrous alloy by carburization contains still a part of the nickel and/or cobalt and can be reverted to the treatment of slag with a result of practically all of the nickel and/or cobalt extracted into the bath of matte eventually being extracted as the high carbon ferrous alloy.
The converter slag resulting from bessemerization of a matte produced by flash smelting of sulfide copper ore or sulfide copper-nickel ore may be treated by "process A"
on a bath of molten matte of low grade matte resulting from slag cleaning furnace; and cobalt that is usually mostly wasted as slag may be recovered. -A large amount of magnetite contained in the slag of copper smelting and nickel smelting may effectively be reduced into ferrous iron with metallic iron in the matte in "process A" with a result of liberating the globules ~ -of matte entrapped in mushy magnetite; and this is effective in recovering not only cobalt or nickel contained in the slag as oxidized compound due to be wasted chemically, but also copper or nickel contained in the slag as suspension of tiny globules that are usually wasted mechanically.
The matte resulting from the present process contains not only a major part of copper but also a minor part of one or both of nickel and cobalt. Therefore, it . . .

~060Z17 may be bessemerized to extract cobalt as a converter slag which may further be ~reated by "process A" or other well-known process to recover cobalt, while nickel is recovered as nickel sulfate in electrorefining or nickeliferous crude copper by well-known means. However, the inventor studied also the bessemerization of such a copper matte and developed a new process for separating nickel and cobalt and recovering one or both of nickel and cobalt as byproduct(s) of copper smelting as explained as follows.
As is well-known, a major part of cobalt contained in a copper matte is oxidized in the slag blow in bessemeriza-tion where practically all of the iron in the matte is slagged off; but the rest of the cobalt is oxidized in the copper blow, where white metal, a bath of copper sulfide, is bessemerized to convert copper sulfide into metallic copper, as viscous scum usually that remains in converter after discharge of the finished crude copper to be included in the slag in the next batch of operation.
In bessemerization of a copper matte containing nickel, most of the nickel ~tays in the matte in slag blow;
but towards the end of the copper blow, a considerable amount of nickel is oxidized to form a scum which is left in the furnace to be treated in the next batch of operation.
Therefore, in bessemerization of a copper matte containing both nickel and cobalt, the oxidized nickel in the scum is mixed with the converter slag from the slag blow of the next batch; and this makes it is difficult to extract cobalt as converter slag of low nickel grade. Thus it has generally been believed that it is difficult commercially to make an effective separation of nickel and cobalt in bessemerization of copper matte based on the tendency of cobalt oxidizing .

. .

'`` i060Z~7 in preference to nickel which has been well-known. Also recovery of nickel into crude copper has been very poor usually because of the nickeliferous converter slag being reverted to the primary smelting where nickel is wasted as slag. The new process developed by the inventor for solving the difficulty is as follows.
The copper blow may be somewhat extended in bessemerization of a copper matte containing nickel so that practically all of the nickel is oxidized alonq with a small part of copper, and this is controlled by the behavior of - samples of molten copper on solidification. The so-called worming of copper, that is a phenomenon of molten copper erupting onto the solidified surface of copper just like a worm creeping on, is an indication for finishing the blow;
and the finished copper is discharged, leaving the scum in the furnace whereby the separation of nickel is effected.
The scum can be recovered by rotating the converter almost up-side-down when it drops or can be scraped-out. Alternatively the extension of copper blow may be shortened to recover nickel partly as scum and partly from the crude copper as a byproduct of electrorefining of copper.
The scum containing nickel contains also copper in an amount comparable to that of nickel, and it may be smelted under reducing conditions to extract the copper and nickel as an alloy which may be treated by the present process for separating copper and nickel.
Cobalt may partly be extracted as a slag from slag blow in bessemerization of copper matte containing nickel and cobalt, while the rest of the cobalt and most of the nickel are left in the white metal. The bessemerization of the white metal in copper blow is suspénded when most of ~060217 the matte is converted into crude metal and matte is ` almost disappearing on the punching rod clearing tuyeres;
and the slag or scum formed is separated from the crude metallic copper. Thus most of the cobalt in the white metal is extracted into the slag or scum, while most of the nickel is still kept in the crude metallic copper, and nickel and cobalt are effectively separated according to the discovery by the inventor.
An extraordinary high efficiency of separation in a narrow range is shown in example 12 that follows in the latter part of the explanation. The slag or scum thus separated contains copper in high grade and can desirably be treated in the next batch of bessemerization of the copper matte; while the bath of crude metallic copper may further be bessemerized in the said manner for treating copper matte containing nickel, and copper and nickel are recovered separately.
Nothing new has been developed for bessemerization of copper matte containing cobalt but no~nickel, but the resulting converter slag may be treated by "process A"
according to the present process with advàntage.
The high carbon ferrous alloy produced by the present process can be treated by well-known hydrometallur-gical means to recover cobalt, if it contains cobalt but little nickel. It may also be treated by "A Process for Recovering Cobalt" for which patent is applied by the inventor as Japanese Application No. 49-17,923 whereby cobalt is recovered as cobalt sulfate solution.
A high carbon ferrous alloy containing a large amount of nickel may be bessemerized with addition of a -sulphur-bearing material, such as nickel matte, sulfur, or .. . .. .. . .
'' ' ' ' ~' : ,' ' ~ ' -~ 10602~

iron sulfide ore to recover nickel as finished matte.
Metallie iron is oxidized in preference to iron sulfide, and metallic niekel reacts with iron sulfide in the matte according to the following equation 3Ni + 2FeS = Ni3S2 + 2Fe to form metallic iron. Therefore, alloy disappears, leaving matte; and the bessemerization can be operated as easily as that of simple nickel matte at a similar temperature, and addition of a nearly stoichiometric amount of the sulphur-bearing material for formation of nlckel sulfide only is suffieient. In other words, oxidation of sulphur ean -~
praetieally be prevented during the bessemerization. The resulting finished niekel matte eontains some copper, for elimination of copper by the present process is not eomplete; but the amount of copper is small enough to be eliminated easily in well-known electrorefining of nickel, for example.
A high carbon ferrous alloy containing nickel and cobalt, especially when it contains a large amount of nickel and a small amount of cobalt, may be treated similarly to recover nickel as finished matte, while most of the cobalt is extraeted as eonverter slag along with most part of iron in the matte and a small part of niekel. Alternatively, a high earbon ferrous alloy eontaining niekel and eobalt, espeeially when it eontains a large amount of eobalt and a small amount of nickel, may be bessemerized as dissolved in eopper matte when major part of eobalt is slagged off along with iron, leaving most of the niekel in matte; and the resulting slag rieh in eobalt lS treated by "proeess A"
to extraet eobalt as a seeondary high earbon ferrous alloy of low niekel grade. Sueh repeated applieation of the ....

present process can be effective not only in separating nickel from cobalt but also in extracting cobalt as a secondary high carbon ferrous alloy of higher cobalt grade than the primary one. This is an effect of "process A"
where major part of iron is eliminated as slag.
The converter slag containing nickel and cobalt produced by the said process or any material containing nickel and cobalt in general may be smelted along with cupriferous material to produce copper matte containing nickel and cobalt which is bessemerized in the said manner to extract nickel, cobalt and copper separately. Alternative-ly slag or material containing nickel and cobalt may be smelted along with copper matte to extract most part of - nickel into the matte while leaving major part of cobalt in the slag; and nickel and cobalt are recovered separately by the said process.
Material containing copper and one or both of nickel and cobalt may be treated in similar manner by the present process, combined with bessemerization of copper matte containing one or both of nickel and cobalt and/or bessemerization of high carbon ferrous alloy, if needed; and the metals are recovered separately.
As has been explained, it is one of the advantages of the present process that complex material containing copper and one or both of nickel and cobalt can be treated by simple copper smelting process or copper smelting process and nickel smelting process with minor alternation to extract the metals separately. Especially, it is of advantage to combine smelting of such oxidized material rich in iron, for example, manganese nodule, laterite, slag from copper smelting - or nickel smelting, that must be treated so that a large ~^
~060Z17 amount of metallic iron must be produced in extracting nickel and/or cobalt by reducing-smelting, with the present process so that the metallic iron produced may be utilized - in separating copper from nickel and/or cobalt; for the separation is achieved economically. It is expensive to treat a material of room temperature by the present process for a large heating expense is needed; but the intermediate product from smelting operation can be treated very economically while it is molten by the present process. It is advisable for an effective application economically of the present process to install the facilities related to the present process, for example, ones for reducing-smelting of oxidized material, copper smelting and nickel smelting, in adjacent position so that the alloy, matte and slag may be transported to the next processing in molten state.
It is another advantage of the present process operated in the manner of "process A" that cobalt can be recovered economically from molten slag. ~nlike well-known process whereby magnetite in the slag is mostly reduced with - metallic iron in the undissolved alloy resulting from reducing-smelting, it is reduced with metallic iron dissolved in the matte; and it is not necessary to heat the large amount of slag as high as the metling temperature of undissolved alloy nor is it necessary to produce metallic iron substantially more in amount than needed for the chemical equilibrium of reduction of oxidized cobalt in the slag, for the metallic iron has a large area of contzct with slag as dissolved in matte.
It is another advantage of the present process operated in the manner of "process A" that the loss of copper ..

or nickel as tiny globules of matte suspended in slag can be prevented by their settling due to elimination of magnetite in slag.
It is another advantage of the present process that nickel and cobalt in raw material can be extracted separately as byproduct(s) of copper smelting or copper smelting and nickel smelting.
It is another advantage of the present process that nickel can be recovered as a byproduct of copper smelting by extracting it as a scum in bessemerization of copper matte.
This invention will be further illustrated by way of the following examples.
Example l A molten alloy containing nickel, copper and iron was run into a graphite crucible containing sulfur, and the resulting sulfurized alloy was run in molten state through a column of lump coke of a size of about 3cm packed into a height of about 2m with cross section of about 200 square cm and heated at about l,400C. The effluent melt was allowed to settle in a crucible and was broken apart into a top and a bottom by hitting after cooling. ~he weights and composi-tions of the charge and the products are shown in Table 1.
Table l Material Weight kg. Composition weight %
Ni Cu Fe S C
alloy 20 20.3 lO.9 66.4 tr 0.4 sulfur 4 top 2 5.4 51.6 17.820.9 bottom 18 21.4 5.3 71.0 0.9 2.5 10602~7 Example 2 A nickle-copper matte and an iron-nickel-copper alloy were melted in a graphite crucible with addition of coke breeze at about 1,350C and was agitated for about 5 minutes by inserted carbon electrode and green wood and was broken apart into top and bottom after cooling. The weights and compositions of the charged materlals and products are shown in Table 2.
Table 2 Materiall~eight kg Composition weigh-t ~
Ni Cu Fe S C
matte 5 31.6 18.2 23.320.8 alloy 20 20.3 10.9 65.40.7 0.4 coke breeze 2 top 5 6.1 41.7 22.920.2 bottom 20 26.5 4.8 65.20.8 2.4 This shows that nickel in a mixture consisting of matte can be extracted into high carbon ferrous alloy, that copper in a mixture consisting of alloy can be extracted into matte, and that nickel in a mixture consisting of alloy and matte is extracted into high carbon ferrous alloy while copper in the mixture into matte by the present process.
Example 3 A molten nickel matte and a molten alloy containing nickel, copper and iron were simultaneously run through a column of lump coke similar to the one used in Example 1 at about l,900C; and the effluent melt was divided into about 10 kg of the top and the rest in a crucible to repeat similar percolations twice. The final effluent melt was allowed to settle in a crucible and was broken apart after cooling into a top and a bottom. The weights and ~060Z17 compositions of the charged materials and products are shown in Table 3.
Table 3 Material l~eight kg Composition weight %
Ni Cu Fe S C
alloy 40 20.3 10.9 65.4 0.7 0.4 matte 10 44.7 27.2 1.2 21.8 top 10 6.7 48.2 16.1 20.4 bottom 38 28.2 5.2 61.8 0.9 2.7 Example 4 A molten copper matte was held in a ladle, molten cobaltiferous converter slag was run onto the bath of the matte, calcium carbide was added, and the whole was agitated for about 3 minutes by inserting a pole of green wood; and the treated slag was discharged, leaving the matte in the ladle. Similar operation was repeated ten times altogether at a temperature of about l,300C.
The resulting mixture of matte and alloy was run through a column of lump coke similarly to Example 3 three times, and the final effluent was allowed to settle in crucibles to be broken apart into tops and bottoms after cooling. The weights and compositions of the charged and discharged materials are shown in Table 4.
Table 4 Material Weight kg Composition weight ~ :
Cu Co Fe S C
copper matte- 1,600 38.1 0.730.2 20.1 conyerter slag 10,0004.6 0.851.6 carbide 260 treated slag 9,5001.3 0.351.2 tops 1,500 58.8 0.616.2 22.2 bottoms 450 8.3 11.872.4 0.9 2.5 ' 106021'7 Example 5 A copper matte of a similar composition to those produced in Examples 1, 2 and 3 was melted in an electric ~urnace equipped with tuyeres and was bessemerized with addition of silica sand. The resulting slag was discharged when most part of iron in the matte was oxidized, and blowing was resumed until a sample of molten copper worms during solidification when the finished crude copper was discharged.
Scum formed was left in the furnace to be discharged separately from copper by turning the furnace up-side-down.
The operating temperature was about 1,250C.
Weights and compositions of the charged and discharged materials are shown in Table 5.
Table 5 Material Weight kg Composition weight %
Ni Cu Fe S
copper matte 3006.2 48.0 16.6 21.5 silica sand 20 slag 90 0.62.8 50.7 crude copper 130 0.6 98.1 tr tr scum 50 29.721.3 6.3 Example 6 A nickel matte was melted in an electric furnace equipped with tuyeres and was bessemerized with addition in two stages of one fifth each time of a high carbon ferrous alloy with a composition similar to that was produced in Example 3 and silica sand, and the resulting slag No. 1 was discharged. Blowina was resumed with addition of one fifth each time of the alloy and silica sand three times, and the resulting slag No. 2 and finished matte were dis-charged after most of the iron charged was oxidized. The 1~60Z~ 1~

operating temperature was about 1,250C.
Weights and compositions of the charged and dis-charged materials are shown in Table 6 Table 6 Material Weight kg Composition weight %
Ni CuFe S C
nickel matte 200 21.7 1.6 46.8 21.5 alloy 200 27.7 5.362.2 0.8 2.5 silica sand80 slag No. 1190 2.8 0.249.8 slag No. 2180 3.5 0.748.3 finished matte 140 60.6 8.5 1.4 2.16 Most of the nickel in thè high carbon ferrous alloy was extracted as finished matte; and the copper content in the finished matte is small enough to be easily eliminated, for example, in electrorefining of nickel.
Example 7 An alloy and a matte containing nickel, cobalt, copper and iron were treated in a manner similar to Example 3;
and a result was obtained as shown in Table 7.
Table 7 Material Weight kg Composition weight ~
Ni CoCu Fe S C
alloy 40 17.6 9.2 10.2 61.1 tr 0.4 matte 5 31.6 1.3 18.2 23.3 20.8 top 5 5.9 1.8 51.7 14.9 20.8 bottom 39 19.8 8.2 5.7 60.2 0.7 2.6 Nickel and cobalt in the charge were mostly extracted as a high carbon ferrous alloy while copper, mostly as matte. This is an example where emphasis was laid on limiting copper content of alloy with some nickel and cobalt remaining in the matte.
Example 8 A high carbon ferrous alloy similar in composition to the bottom produced in Example 7 was treated similarly .
to Example 6, and a result was obtained as shown in Table 8.
Table 8 M2terial Weight kg Composition weight %
Ni Co Cu Fe S C
nickel matte 200 21.70.51.646.8 21.5 alloy 20020.2 8.65.359.1 0.3 2.5 finished matte 110 60.11.6 .10.40.8 21.8 slag No. l 200 3.1 2.90.350.6 slag No. 2 180 3.8 5.50.648.6 This is an example where a high carbon ferrous alloy containing nickel and cobalt was treated jointly with nickel matte; and the nickel content was extracted as finished matte while cobalt content, mostly as converter slag.
Example 9 A copper matte similar in composition to the top produced in Example 7 was treated similarly ~o Example 5;
and a result was obtained as shown in Table 9. Besides, a sample of white metal was taken when converter slag was discharged after oxidation of iron is almost finished; and cobalt slag was discharged and a sample of unfinished crude metallic copper was taken with interruption of blowing when matte almost disappeared on the punching rod towards the ~:~
end of copper blow.

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~060Z~.7 Table 9 Material Weight kg Composition weight Ni CoCu Fe S
copper matte 300 5.52.0 :.50.8 15.4 20.5 converter slag 85 0.44.5 3.1 46.8 white metal 6.5 0.863.6 2.5 21.6 cobalt slag18 1.3 7.216.5 9.6 unfinished copper 10.4 0.4 85.8 0.3 1.8 finished copper 130 0.5tr 98.5 tr tr scum 45 29.2 1.522.7 7.7 The result shows that the nickel and cobalt which were included partly in matte in Example 7 can be extr~cted with a good recovery as scum and converter slag respectively.
Cobalt slag may preferably be reverted to the next batch of treating similar copper matte, for its copper grade is high.
Example 10 A copper matte was melted in the electric furnace used in Example 6, and slag No. 1 and slag No. 2 from , Example 8 were smelted on the bath of matte with blowing for about two minutes. Weights and compositions of the charged and discharged materials are shown in Table lO. -Table lO :;
Material Weight kg Composition weight ~
Ni Co Cu Fe S
copper matte150 tr tr 35.9 32.0 21.1 slag No. 1lO0 3.1 2.9 0.3 50.6 slag No. 2 80 3.8 5.5 0.6 48.6 discharged slag 230 0.8 2.8 2.6 50.3 discharged matte 90 4.6 0.8 52.8 l1~8 20.8 30This is an example of extracting nickel from a molten slag into copper matte by washing, leaving most '. ~;
, . ' , ~

1060Z~7 of the cobalt in slag. Combining Example 8 and Example 10, it is clear that practically all of the nickel in a high carbon ferrous alloy can be extracted as finished matte;
and it is also shown that cobalt ln the high carbon ferrous alloy is extracted as a cobaltiferous slag of low nickel content, for nickel and cobalt contained in copper matte can be extracted separately as is shown in Example 9.
Example 11 ~Sanganese nodule was crushed into sand and was smelted with addition of silica sand and coke breeze; and a result as shown in Table llA was obtained. An alloy of a similar composition to the resultant alloy was treated similarly to ~xample 2, and a result was obtained as shown in Table llB.
- Table llA
Material Weight kg Composition weight %
Ni Co Cu Fe C- ~Sn Manganese nodule 2 1.2 0.50.9 19.0 31.6 silica sand 0.1 coke breeze 0.1 alloy 0.17 11.7 3.6 8.569.7 0.8 0.9 slag 1.3 tr 0.10.2 18.6 43.3 Table llB
Material Weight kg Composition weight %
Ni Co Cu Fe S C Mn alloy 20 11.1 3.89.0 68.1 1.1 1.2 1.0 matte 2 31.6 1.318.2 23.3 20.8 top 2 4.8 0.943.7 17.3 21.0 2.3 bottom 19 13.2 4.04.3 68.4 0.8 2.6 0.7 The resulting bottom alloy can be treated similarly to Examples 7 to 10 to recover copper, nickel and cobalt.

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:1060217 Example 12 A white metal containing cobalt and nickel was melted in the furnace used in Example 5 and was bessermerized.
B]owing was interrupted several times towards the endi and samples of crude copper, matte and slag were taken.
Bessemerization was finished after blowing upto the ordinary point of copper smelting, and the resultant crude copper and scum were discharged. ~eights of the charged and discharged materials and compositions of the samples and charged and discharged materials are shown in Table 12.
K in the table was calculated accordlng to the following :equation; and A, B, C in the table are for crude copper, matte and slag respectively; while 1, 2 and 3 are samples in the order of taking, and 4 is for discharged materials.
K=(Co weight ~ in slag)~Ni weight % in crude copper or matte) (Co weight % in crude copper or matte)(Ni weight % in slag) Table 12 - Material Weight kg Composition weight %
CoCu Fe S Ni K
white metal 720.9 69.6 2.6 20.1 1.0 20` lA 0.892.4 0.5 1.8 2.5 47 lB 1.078.5 1.4 17.5 1.1 16 lC 7.57.2 32.4 0.5 2A 0.494.4 0.2 1.6 2.1 133 2C 7.66.8 35.3 0.3 3A 0.296.2 0.1 1.2 1.7 63 3C 6.714.8 30.1 0.9 4A 46 0.0598.0 0.03 0.04 0.5 18 4C 13 4.622.9 24.2 2.9 As indicated by the values of K in the table, separation of nickel and cobalt is the best in the case of 2A and 2C; while it is poor in case of ordinary finishing ~25-. .
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10602~7 in eopper smelting whieh is shown by 4A and 4C~ Sulfur eontent of the erude eopper 2A is much higher than the finished eopper, showing 1.6~ S. Iron in the products is more in amount than in the eharge because of the accretion to the furnaee being melted.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED
AS FOLLOWS:

1. A process for separating nickel, cobalt and copper comprising the steps of mixture in molten state containing copper and at least one member selected from a group consisting of nickel and cobalt in the presence of matte, metallic iron and carbon so as to form a high carbon ferrous alloy containing more than 0.5 percent by weight of carbon and a matte in two separate phases and extracting the major part of said member as thus formed high carbon ferrous alloy and the major part of copper as thus formed matte.

2. A process according to claim 1 wherein said mixture consists of an alloy.

3. A process according to claim 1 wherein said mixture consists of a matte.

4. A process according to claim 1 wherein said mixture consists of an alloy and a matte.

5. A process according to claim 4 wherein said alloy contains at least one member selected from a group consisting of copper, iron, nickel, cobalt, carbon, and sulfur, and said matte contains at least one member selected from a group consisting of copper sulfide, iron sulfide, nickel sulfide, cobalt sulfide, and metallic iron.

6. A process according to claim 1 wherein said mixing step is made in the presence of a sufficient amount of matte for converting a major part of the copper into matte.

7. A process according to claim 1 wherein said mixing step is made in the presence of an amount of metallic iron that is greater than the total amount of nickel and cobalt.

8. A process according to claim 1 wherein said mixing step is made in the presence of an amount of carbon in the form of red hot lump coke that is greater than is required to make the carbon content of the high carbon ferrous alloy 0.5 % C.

9. A process according to claim 1 wherein said mixing step is made in the presence of a matte containing predominantly at least one member selected from a group consisting of copper sulfide, iron sulfide, nickel sulfide, and cobalt sulfide.

10. A process according to claim 2 wherein said mixing step is made in the presence of a matte obtained by a reaction of a part of the alloy with sulfur.

11. A process according to claim 1 wherein said mixing step is effected by agitating said mixture in a furnace in molten state.

12. A process according to claim 1 wherein said mixing step is effected simultaneously with carburization by passing said mixture through a column formed of lump carbon.

13. A process according to claim 2 wherein the matte is separated from the alloy containing dissolved sulfide through carburization of the alloy.

14. A process according to claim 3 wherein said high carbon ferrous alloy is separated from the melt of matte containing dissolved metallic iron through carburization of the melt.

15. A process according to claim 11 wherein said mixture is made up by bringing a molten alloy and a molten matte together.

16. A process according to claim 4 wherein said mixture is produced by smelting an ore containing copper and at least one member selected from a group consisting of nickel and cobalt to extract the copper and at least one member as an alloy and a matte.

17. A process according to claim 2 wherein said mixture is produced by smelting, under reducing conditions, an ore containing copper, iron and at least one member selected from a group consisting of nickel and cobalt in oxidized state to extract the copper and at least one member as an alloy.

18. A process according to claim 2 wherein an alloy containing nickel, cobalt, copper and iron produced by reducing and smelting manganese nodule is treated.

19. A process according to claim 4 wherein said alloy is produced by smelting manganese nodule and said matte is produced by smelting nickel-copper sulfide ore.

20. A process according to claim 16 said mixing step is effected by said smelting with addition of a sufficient amount of solid carbon to effect a carburization of the alloy.

21. A process according to claim 3 wherein said mixture is produced by smelting a molten slag containing at least one member of nickel and cobalt on a bath of molten matte containing at least copper and metallic iron.

22. A process according to claim 21 wherein said bath of molten matte containing metallic iron is obtained by dissolving a material containing metallic iron into matte in molten state.

23. A process according to claim 21 wherein metallic iron is produced by an exothermic reaction between oxidized iron in the slag and reducing agent and is dissolved into said bath of molten matte.

24. A process according to claim 1 wherein the formed high carbon ferrous alloy and matte are bessemerized separately.

25. A process according to claim 1 wherein the formed matte is bessemerized to extract nickel contained therein as scum.

26. A process according to claim 1 wherein the formed high carbon ferrous alloy is bessemerized with addition of a sulfur-bearing material to extract nickel in the alloy as a finished matte.

27. A process according to claim 26 wherein cobalt in the formed high carbon ferrous alloy is extracted as a converter slag.

28. A process according to claim 1 wherein the formed high carbon ferrous alloy is bessemerized together with matte containing copper and cobalt in said alloy is extracted as a converter slag.

29. A process according to claim 21 wherein a material containing nickel and cobalt is smelted together with a cupriferous material to extract nickel and cobalt in the resulting copper matte, the resulting copper matte containing nickel and cobalt is bessemerized to extract cobalt as a converter slag, and the resulting molten converter slag is treated on said bath of copper matte containing metallic iron, whereby cobalt is finally extracted as the high carbon ferrous alloy and nickel is extracted as white metal containing nickel and separation of nickel and cobalt is effected.

30. A process according to claim 29 wherein bessemerization of said resulting copper matte containing nickel and cobalt is suspended during copper blow near the point where white metal almost disappears and cobalt remaining in white metal is extracted as an oxidized cobaltiferous material of low nickel grade.

31. A process according to claim 21 wherein a molten slag containing nickel and cobalt is washed with a molten copper matte free from metallic iron to extract nickel into the copper matte and the resulting molten cobalt-iferous slag is treated on said bath of copper matte containing metallic iron so that the cobalt is extracted into the latter matte whereby cobalt is finally extracted as the high carbon ferrous alloy and nickel as the nickeliferous copper matte and separation of nickel and cobalt is effected.

32. A process according to claim 21 wherein a high carbon ferrous alloy containing nickel and cobalt is bessemerized with addition of a sulfur-bearing material and the resulting molten converter slag is treated on said bath of molten copper matte containing metallic iron whereby nickel is finally recovered as finished matte and cobalt as the secondary high carbon ferrous alloy and separation of nickel and cobalt is effected.