US2266155A - Metallurgical process - Google Patents

Description

Dec. 16, 1941.

NG2CO3 +H2O 20 lbs. dispersant per lOQO gols H2O per ton of Ore J. J. BONESTEEL METALLURGICAL PROCESS Filed May 51, 1959 Ore Au +X Pulverizer Agitator- Brown to cherry, red liquor Toke up in Aquo Regicl. Chlorinoie or Treat with NoCN I Recover by Known Methods Agitclle l6-48 hrs.

. Redisperse gongue 2 Sheets-Sheet l Comminuie to 200 Mesh Coogulotor Heot until flocculation lncinerote filter paper 81 melt residue I (far/2&5

bullion OCCUI'S Dec. 16, 1941.

, .1. .1. B ONESTEEL 2,266,155 METALLURGICAL PROCESS Filed May 31, 1939 2 Sheets-Sheet. 2 Ore Au X Pulverizer Commmute to 200 Mesh Time interval continues until .all action ceases (IS-24 hrs) 6/ H202 gal. per lb. Ore

\ Fluid and slime Conc, HC Time interval continues Sufficient To until all action ceases {:omplete reaction Fluid,slime and scum Wash in H20 F Sufficient to free} from HCL V Residue O 1 dlGlyco' Loumte; Agitator Agitate l6 hrs. [gal-Sqjs. per lb. of

Concentrate Cherry re d liquor Wash residue in Residue H2 0 until free from color Treat filtrate with A ua Regia v q -%//@j7z vz cmas c/fiarzas/el Take up Au D313:- known methods Patented Dec.116, 1941 UNITED STATE 3' PATENT orrlcs This invention concerns itself with the extraction of gold found in finely divided form in sedimentary or argillaceous rocks or'like substances. Gold has hitherto been found in such formations in certain localities, certain types of limestone being an example, but fire assay results thereon are very variable, running from a trace to substantial values. a

One method of extracting gold from ore of this type is described in copending application of Henry Jeifs and E. J. Dunn', Serial'No. 238,646, filed November 3, 1938, to which reference is hereby had for the methods there disclosed. This invention concerns itself with an alternative method for extracting gold from such ores.

It is not known in what state, either physical or chemical, the gold is contained in theseores other than that, in whatever state it may be found, the size of the particles is sub-microscopic, hereinafter referred to for convenience as gold micelle or micellic gold. The actual size of the gold micelle may vary from a few-millimicrons for the smallest, up to one micron for the largest. Whether the gold is free or in the form of oxides or salts is not known. It has been found, however, that by the use of certain reagents the gold micelle in the ore can be put I into a colloid state in a hydrosol from which the values can readily be extracted by known methods.

The object of this invention, therefore, is to provide means to extract micellic gold from its ores throughdispersion into a hydrosol. Two methods of accomplishing this result present themselves, one comprising a direct method of putting the micellic gold from the ore into a hydrosol, and the other comprising an indirect method after concentrating th ore. The direct method is diagrammatically shown in the flow sheet marked Fig. 1 in the drawings; the indirect method is shown in the flow sheet marked Fig. 2.

Direct method The ore is first comminuted as finely as can conveniently be done.- Ordinary comminution agent, such as sodium carbonate, in water. In

practice half. a gallon of water has been used per 7 pound of ore. The

' within a short time interval, aboutone half hour.

dium hydroxide,

It is to be understood, however, that the quantity'and type of dispersing or peptizing agent will vary with the type of ore treated and the optimum can only be determined after some experiment.

As a dispersing or peptizing agent, sodium carbonate is preferred, although sodium oxalate, so

ammonium hydroxide and diglycol laurate have been found useful. Many other dispersing agents are known in the chemical arts, but the permutations of their numberand chemical properties make. it impossible to disclose their efiect in or pertinence to the use in the described process.

After the addition of the dispersing or peptlzing agent, the liquor is shaken or agitated, the time interval used'in practice being sixteen to forty-eight hours. During the agitation interval. the gold micelle in the or will be dispersed by the dispersing or peptizing agent into a'colloid state, in a liquor characterized by typical colloid colors. Sodiumcarbonate will produce a hydrosol characterized by a brown or cherry red color within a short time interval. As its action continues, the color of in'from' twenty-four to forty-eight hours, it becomes an intense brown or red. At this point,

" the agitation and dispersion step is completed.

It has been found that a very much longer time interval will produce a liquor having a black color to reflected light. If the liquor is per-. mitted to stand, even without agitation, for a period of from ninety to one hundred twenty days, dispersion of the micelle from the gangue will continue withthe black color.

After the agitation and dispersion step, the liquor is filtered through a paper filter, and the gangue is washed in water through the filter until the water coming through is free from color.

The gangue remaining may be considered as y tailings, although it is ordinarily good practice" to redisperse or peptize the gangue and pass it through the agitation and filter stages, as previously described, until no further hydrosols-cen be established through the dispersion and agitation. The filtrate, as pointed out, may vary from a the liquor will deepen until eventual result of such a.

described; a

ta'l'la' lm to a black color in reflected light. The gold can be extracted from the filtrate through dissolution by known methods, as chlorination,

aqua regia or sodium cyanide, for example.

Alternately, the gold may be extracted from the filtrate through coagulation, comprising the :addition of a coagulate such as. for example,

acetic or a mineral acid in an amount 'suiiicient tomelte the solution distinctly acidto litmus.

After addition of the coagulant, the liquor should be heated until flocculation occurs. coagulated liquor is then filtered through I. treated 1 its ores, that process which comprises comminu- .paper filter or an extremely fine porcelain filter,

the values being recovered known methods.

Indirect The indirect method, diagrammatically shown in Fig. 2 of the drawings. comprises first con-' centrating the ore after it has been comminuted as previously described. v

After comminution. the ore is first treated with asix per cent. solution of hydrogen peroxide in the amount" of one half gallon of solution per pound :of ore, th'e timeinterval for the reactioncontinuing until allaction ceases, probtion of the ore, dispersion of the gold or its compounds by physico-ch'emical means from the ore into a colloid state, filtration from the gangue' oi the liquor resulting from dispersion, and recovery oi the gold from the filtrate.

2. In the art of extracting gold micelle from its ores, that process which comprises comminuting the ore, dispersing the gold or its compounds thereinuby P Wco-chemicalImean's into a. hydrosol, having a characteristic gold colloid color, filtration of the hydrosol from the gangue, and recovery of the gold from the hydrosol.

' 3; In the art of recovering gold micelle from the natural state, those steps in the process comprising attacking'treated ore containing the micelle with a gold-selective dispersing or peptising agentand agitating the liquor until a gold hy- 'd'rosol is formed. 4. In the art of extracting gold micelle from V i its ores, that process which comprises comminuably sixteeri'to'twenty-folmhohrs, the result be- 8 a fluid'a n'd slime.

' The product is then treated with concent ated Y hydrochloric "acid in amount suiilcient' to complete the reaction, leaving the solution still slightly i-acid, after which the product comprises a mixture of fiuid slime-and scum, the mass of slime-being approximately one-tenth of the originalsggregate. The :product is then filtered without dilution is then shaken or agitated for a interval,

sixteen hours having been found "adequate in.

practice, during the course of which it will acquire a deep cherry red color.

The liquor is then filtered through-a filter paper and the residue washed in water until -no more color comes through,at ter which the gold'may be captured from the liquorthrough dissolution by chlorination or aqua regia. or y coagulation and further filtration as previously "Nicene" is herein microns up to It is to be understood that the foregoing deone micron, lacking appreciable scription is illustrative only and may be departed from, in so far as the resort to equivalents is concerned. without a departure from the spirit of the invention.

Having fully described the invention, 1 claim:

defined to cover minute, particles having a diameter from a few milligold hydrosol. having a "tion of the ore, concentration of the ore through the reaction of solvents therefor, treatment of the concentrate with a gold-selective dispersing or peptizing agent, the formation of a gold hydrosol, having a characteristic gold colloid color, and the recoveryof the gold from the hydrosol.

5. In the hrt of extracting gold micelle from I its ores after the same havebeen concentrated through the reaction of solvents, that-step which comprises attacking the concentrate with a gold- .selective dispersing or agent.

8. In the art of reo0vering "gold micelle from the natural state. those steps in the process comprising attacking concentrated ore containing the micelle- -with a gold-selective dispersing or poptizing agent and agitatingthe liquor until a characteristic gold colloid color, is formed.

r. In th'e art of recovering gold micelle from the natln-al state, those stepsin the process comprising attacking comminuted ore containing the micelle with a gold selective dipsersing or peptizing agent and agitating the liquor until a gold hydrosol, having a characteristic gold colloid color, isformed. v

8. In the art of recovering gold micelle from the natural state, those steps in the process comprising attacking treated ore containing the micelle with a gold-selective dispersing or peptizing agent and permitting the liquor to stand until the natural state, those steps in th'e process coma gold hydrosol, having a characteristic gold colloid color, is formed.

9. In the art of recovering gold micelle from .prising attacking concentrated ore containing the micelle with a gold-selective dispersing or peptizing, agent and permitting the liquor tostand until a gold hydrosol, having-a characw .teristie gold colloid color, is formed.-:

- 1. In the art of extracting gold mice le from 10. In the art of recovering gold micelle from the natural state, those steps in the process comprising attacking comminuted ore containing the micelle with a gold-selective dispersing or peptizing agent and permitting the liquor to stand until a gold hydrosol, having a characteristic gold colloid color, is formed.

' JAMES J.

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