US1335001A - Metallurgical process - Google Patents

Description

l and Gnonsn B; FRANKroRrER, citizens of the .United States,

Y UNITED STATES PATENT orriou.

HENRY B. HOVLAND, OF DULUTH, AND

To all whomtt may concern:

Be it known that we, HENRY B. HOVLAND residing at Duluth, St. Louis county, and Minneapolis, Hennepin county, Minnesota, respectively, have invented certain new and useful Im rove'ments in Metallurgical Processes; an we do hereby declarej the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to metallurgical processes, and it comprises more particularly a process wherein metal sulfid concentrates or analogous materials, comprising more or less gangue are 'first roasted to oxidize substantially all the metal of the metal sulfid and to loosen and separate gangue from the metalliferous particlesof the concentrates, the roasted concentrates are then resulfidized for the purpose of dislodging any-remaining gangue, the resulting metal sulfid is then subjected to treatment by'a suitable flotation process whereby substantially pure metal sulfid concentrates are obtained.

Sulfid concentrates of metals such as copper, lead, silver, zinc, nickel, cobalt, manganese, iron,- etc., as heretofore obtained greater or less proortions of gangue materials which it has een customary to remove by smelting processes involving the use of purifying fluxes and expensive high temperature treatment.

We regard the present process as of particular importance in connection with the treatment of copper sulfid concentrates obtained by any method. The application of all the process will therefore be described as applied to copper sulfid concentrates for purposes of illustration, it being understood, however, that the invention is not limited to copper concentrates, but extends to metal sulfid concentrates and analogous nietalliferous materials in general, including Briefly described, the present process,

' when applied to copper sulfid concentrates,

consists in subjecting such concentrates obtained by any suitable concentrating method to a roasting operation. This roasting operation may be carried on at temperatures METALLURGICAL PROCESSQ snoaen B; raanxroarn t, or. MINNEAPOLIS, unmnso'ra; sun rmxronrmr. assrenon :0 sun HOVLAND. f

Patented Mar. 30, 1920.

Serial a. 794,940. Renewed Octoberi), 1916. Serial 110. 127,307." I a in the neighborhood of 350 -to" 'l0()" (l, or even higher in some instances,ibut at no time should the temperature be sufliciently high to bring about fusion of. the materials bemg roasted. After the roasting operation is sufliciently completefthe resulting roast-- ing materials containing the .copper largely in oxidized condition may, if-necessary, be ground to a suitable degreeof fineness'in preparation for the next step in the process. By oxidized condition isjmeant the usual chemical forms resulting from the roasting operation, such as oxids, sulfates and the like of the metals treated.

The finely divided roasted material is now mixed or pulped with a rather dilute solution of an acid, suchas sulfuric or sulfurous acid, and the mixture or pulp is subjected to the action of a sulfidizing agent, such as hydrogen sulfid, which may be introduced into the pulp either as a gas or in aqueous solution. The strength of the acid solution employed may vary considerably but a content of from one to five per cent. of sulfuric acid is found in practice to be a convenient and effective strength. The quantity of acid solution used naturally varies with the copper content of the material treated.

In this sulfidizing operation, the oxidized copper is converted either entirely or merely superficially into copper sulfid; and this con version is accompanied by a mechanical loosening or dislodgment of any gangue materials still adhering to. the metalliferous particles.

The acidified sulfidized mixture is then threated by any suitable flotation process in order to obtain substantially pure sulfid concentrates; for example, the sulfidized pulp may be agitated with a suitable quantity of an oil, such as kerosene, or other equivalent material, the pulped ore being.) thoroughly aerated during the agitation with the oil, whereupon the metalliferous sulfid particles float and collect at the surface of the flotation liquor where they may .be skimmed oil in any suitable way. The

manner just described are substantially pure copper sulfid being practically free from gangue materials of any kind.

While our .new process is articularly adapted to the treatment of s fid concentrates, the process can nevertheless be apwell adapted to treatment by the present- "process; as is also copper matte. Ores carrying values partly as sulfids and partly in oxidized condition may also be treated with advantage in the manner described. It is to be understood that the materials treated may contain more than one of the metals speclfidized without In applying our process to the recovery of metals like zinc, manganese, etc., whose sulfids are soluble in sulfuric or other strong acids, the sulfidizing operation is carried out in neutral or alkaline solution. urally also, other specific details of the process as described for copper must be modified as a rule to some extent according to the particular metal sought.

In some instances it is advantageous to modify the sulfidizing step. somewhatby first bringing the metal to be recovered into solution after the first 'roast, then separatingthe solution from the 'gangue more or less completely as by decantation, and then sulfidizing and floating. This procedure gives a separation of the metal values from the bulk of the gangue prior to sulfidizing. If desired, the dissolved copper may be suldecanting the solution from the gangue.

Various sulfidizing agents may be em-.

'- ployed in the forego' g process, and they may be variously app ed. a

The copper or other metal may .be recovered from the flotationconcentrates by any suitable method; and-the flotation tailings, particularly where a preliminary concentration of the ore has been effected, may be treated for the recovery of precious or other metals still contained therein, as by the cyanid process.

What we claim is:

1. The process of-extractingmetal values from metalliferous material which comprises roasting such material in order to oxidize the metal sought, convertin such oxidized metal at leastpartl into sull d, and subjecting the resulting su fidized material to treatment by flotation.

2. The process of extracting metal values Natfrom material carrying a metal sulfid which comprises roastingsuch material in order to oxidize the metal, sulfidizing the roasted material in the presence ofan acid, and concentrating the sulfidized material by flotation.

3. The process of extracting metal values -which comprises roasting a material carrying copper sulfid in order to oxidize the co per, sulfidizing the oxidized copper in the presence of an acid, and concentrating copper sulfid by flotation.

4. The process of extracting metal values from metalliferous material which comprises roasting such material to convert the metal valuesv therein to oxidized condition, dissolving the metal values of'the roast, precipitating the dissolved metal values as sulfid, and concentrating the sulfidized material h flotation. a

-5. he process of extracting 00 per from material containing the same, w 1011 comprises roasting such material to convert the copper into oxidized condition, dissolving the oxidized copper of the roast, precipitating the copper as sulfid, and concentrating the copper sulfid by flotation.

6. The process of treating material for the extraction of values, which comprises subjecting the materials to be treated to the-action of sulfurous acid, adding a sulfidizing agent, and recovering values by flotation.

7 The process of extracting metal values from material containing the same, which comprises roasting such material to oxidize the metal sought, subjecting such roasted material to the action of a solvent for the metal to be'extracted, recipitating the dissolved metal as sulfi in the gangue, and separatingsaid sul sociated gangue by flotation.

tpresence of d from as- 8. The process of treating material, which comprises subjecting the material to a roasting operation, to the action ofsulfurous acid, to the action of a sulfidizing agent, and to a flotation o eration.

9. The process 0 treating metalliferous material, which comprises subjecting said material to the action of sulfurous acid, in-

' troducing a sulfidizing agent, and separating the values.

10. The process of extracting metal values which comprises roasting the material carrying copper sulfid in order to oxidize the copper, sulfidizing the oxidized co per, and concentrating copper sulfid by flotation. t

11. The process of treatin metalliferous material for the extraction 0 values, which comprises subjecting the material to be treated to the action of sulfurous acid, addin a sulfidizing a ant, and se arating va ues from associatet l 12. The process of treating cupriferous gangue by I otation.

and separating the values.

comprises subjecting the material to be treatedto the action of sulfurous acid, adding a precipitating agent, and separating the precipitated values from associate gangue by flotation.

14. The process of treating metalliferous material which comprises subjecting said material to the action of sulfurous acid, introducing a sulfidizing agent to precipitate the metal values in the presence of gangue,

15. The method of treating materials for the recovery of metals which comprises subjecting pulp to the effect of products of reaction between a soluble sulfid and a metal sulfite.

16. The method of treating materials for the recovery of metals which comprises sub-- jecting pulp to the effect of products of reactions between sulfurous acid and a sulfid.

17. The method of recovering metal values from material containing the same which comprises subjectin said material to the action of sulfurous acid, separating solution from gangue more or less completely,

then sulfidizing in presence of the bulk of the gangue, and separating values from gangue by flotation.

18. The method of recovering copper from ores carrying copper in oxidized condition comprising subjecting such ore to the action of sulfurous acid, precipitating copper values in the presence of gangue, and separatin precipitated copper values from associate gangue by flotation.

19. The. process of treating ores carrying values partly as sulfid and partly in oxidized condition comprising subjecting such ores to the action of sulfurous acid, to the action of a sulfidizing agent, and to a flotation operation.

20. he process of treating ores carrying values partly as sulfid and partly in oxi- IIGSSGS.

dized condition comprising subjecting such ore to the action of sulfurou's acid, to the action of a sulfidizing agent, and floating artificial sulfids so produced in the presence of native sulfids of the original ore.

21. The process of treating ores carrying values partly as sulfid and partly in oxidized condition comprising subjecting such ore to the action of sulfurous' acid, separat ing solution from gangue more or less completely, sulfidizing' in presenceof the bulk of the gangue and floating artificial sulfids so produced in the presence of native sulfids of the original ore.

22. The process of treating ores carrying values partly as sulfid and partly in oxidized condition comprising subjecting such ore to the action of sulfurous acid, separating solution'from gangue more or less completely, precipitating values in the presence of the bulk of the gangue and floating precipitates so produced in the presence of native sulfids of the ori inal ore.

23. The process 0 treating ores which comprises subjecting the same to a preliminary treatment to loosen and separate the gangue from the metalliferous particles, and then subjecting the thus treated ore to the action of solvent, precipitating the metal values by a sulfidizing agent and then concentrating the sulfidized material by flotation.

24.. The process of treating ores which comprises subjecting the same after concentration to a preliminary treatment to loosen and separate the gangue from the metalliferous particles, and then subjecting the thus treated ore to the actionof solvent, precipitating the metal values by a sulfidizing agent and then concentrating the sulfidized material byflotation.

In testimony whereof we hereunto afiix our signatures in the presence of two wit- HENRY B. HOVLAND. GEORGE B. FRANKFORTER.

Witnesses:

'R. F. STEWARD, E. O. HI'LDEBRAN