US849097A - Apparatus for extracting metals from their ores. - Google Patents

Description

PATENTED APR. 2,1907.

' 0; R. ARNOLD. APPARATUS FOR BXTRAOTING METALS FROM THEIR ems.

APPLICATION FILED JUNE 4, 1904.

2 RM A A; MB A .m wm

WITNESSES:

A TTORIVEVS rm: unkms PETERS co, WASHINGTON, D. c.

UNITED STATES PATENT OFFICE.

CRAIG RITCHIE ARNOLD, OF PHILADELPHIA, PENNSYLVANIA.

APPARATUS FOR EXTRACTING METALS FROM THEIR ORES.

Specification of Letters Patent.

Patented April 2, 1907.

To all whom, it may concern:

Beit known that I, CRAIG RITCHIE ARNOLD, a citizen of the United Sates, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, with post-office address as above, have invented certain new and useful Improvements in Apparatus for Extracting Metals from Their Ores, of which the following is a specification.

My invention relates to apparatus employed in processes of recovering metals from ores, tailings, concentrates, slimes, or other metal-bearing substances by agitating a pulp consisting of the metal-bearing substance and a suitable chemical solution in the presence of air employed as an oxidizing agent in the process.

The main object of the invention is to provide a simple and effective apparatus suitable for use in the cyanid process of recovering gold, silver, and other precious metals and which in addition to a thorough and complete agitation of the pulp in the presence of the oxidizing medium shall be entirely free from the objections attendant upon the use of the apparatus heretofore employed.

To this end the invention consists in the combination of apparatus hereinafter described and then specified in the claims.

The accompanying drawings illustrate in side elevation and section an apparatus embodying my invention.

5 indicates the treating tank or vat, which may be of any desired form and is provided with a hopper through which the tank may be charged.

7 indicates the discharge-opening, through which the treated pulp is emptied into a settling-tank 15 or otherwise removed for recovery of the solution and separation of the metallic constituents thereof.

The tank is preferably made of conical form at its bottom to assist in the discharge of the pulp and, further, to facilitate the movement of the mass of pulp under the action of the stream of gas introduced into the mass of the pulp at the lower end of the tank through pipe 25, having a suitable opening or openings within the tank or vat. Said pipe opens into the body of pulp at or near the center of the bottom of the tank, so as to be in proper position to agitate the pulp thoroughly by the action of the stream of gas drawn through the pipe 25 by the vacuum maintained above the body of pulp.

26 is a suitable pipe opening into the gasspace at the top of the tank and through which the gas or gases therein are removed by suction produced by the action of a suitable pump, the function of which is to maintain a partial vacuum in the tank 5.

The pipe 25 communicates with the atmosphere, so that by the operation of the vacuumpump connected to the pipe 26 a flow of gas will be produced by suction through pipe 25 and up through the pulp in the tank 5 to agitate the same. Interposed between pipe 25 and the atmosphere is a suitable generator 4 of a halogen or other reducing gas. Said generator is here typified by an ordinary Woulfe bottle.

As a means for maintaining a partial vacuum in the treating tank and pipe 26 or other passages by which the excess or waste gases are conducted away I prefer to employ a vacuum-pump 9, which may be of the wellknown Sprengel type and preferably operated bywater conducted thereto under pressure by a pipe provided with a stop-cock 10, said water being delivered through pipe 11 into the pot or tank 12, containing water in which the outlet of the pipe 11 is submerged. The head of water and the volume of flow thereof will obviously determine the degree of vacuum which can be maintained, and hence the rate of flow of air introduced into the body of pulp through the pipe 25, which rate of flow in order to satisfy the requirements of my invention must be sufiicient to thoroughly agitate the body of pulp, and so bring all the metal-bearing constituents thereof into effective contact with the oxidizing medium, which in the case supposed is air.

By the use of a vacuum-pump of the water type having its outlet submerged as described I secure the advantage that the waste or excess gases passing from pipe 26 to and through the pump will commingle with the waste water and produce ,a harmless compound. Ordinarily, however, I prefer to interpose between the pump and the tank one or more absorption vats or tanks 8 of the ordinary type, in which the gas is caused to pass through a solution of material suitable for chemically uniting with the gas or gases taken from the tank and so operating either to render the same harmless or to recover the same in suitable form to permit the recovered elements to be again employed in the treating-tank. Thus, for instance, in the cyanid process said absorption-tanks 8 might contain a material suitable for uniting IIO with the hydrocyanic-acid gas generated in thetreating-tank, in which case they would be preferably chargedwith some caustic solut1onsuch as a solution of caustic soda, caustic lime, caustic potash, or any other caustic alkali or alkaline earth adapted to unite with or absorb hydrocyanic acid-thus producing a simple cyanid adapted to act as a solvent for gold, silver, or other metalbearing ore or pulp undergoing treatment in the tank or vat 5. By thus combining absorption tanks or bottles and a hydraulic exhaust-pump in the passage between the outlet of the tank and the atmosphere I am able to insure the complete absorption of any of the deleterious products of the process being conducted in the tank 5 and at the same time am enabled to thoroughly recover the valuable released gases or elements for use in connection with fresh bodies of ore or other metal-bearing substances. This result is due to the fact that when proper attention is paid to the character or strength of the absorbing solution in the absorption vats or tanks 8 such solution will thoroughly absorb the hydrocyanic gas generated or released in the pulp-containing tank; but if any such gas should possibly pass the absorption tanks or vats it, together with any of the other deleterious gases which the solution fails to take up, will commingle with the Waste water of the pump and be rendered harmless.

The generating material may be introduced into the bottle 4 through the funnel 13. Said bottle is preferably of glass, so that the quantity of such material can be observed. Preferably the air introduced into said bottle throu h pipe 1 is carried through the heater-coil 2 in a heater 3, and the pipe 1 may be provided with an inlet-funnel 14 for the introduction of any oxidizing or reducing agent. It will be understood, also, that the contents of the bottle 4 may be such as to produce other oxidizing or reducing agents besides bromin. Also, as will be obvious, when bromin is employed the absorption tanks 8 may be charged with a solution of alkali, which will combine with the bromin or other gas of the halogen group that may be passed through the pulp and escape by the pipe 26.

In the operation of the apparatus described the pulp in the tank 5 is mixed with a suflicient amount of solution to render it capable of being agitated or stirred by the action of the gases drawn up through the same from the pipe 25 to the space with which the pipe 26 communicates, and in which space the partial vacuum is maintained, as already described.

It will be seen that in my process the agitating is produced not under pressure of gas, but under a partial vacuum in practically all the pipes or spaces in which the gas exists, and the escape of gas is thus avoided even though there should be a defect or opening through which leakage would otherwise occur. This advantage applies obviously to the inlet as well as to the exit pipe or space, wherein the excess or waste gases resulting from the treatment exist. Moreover, it will be seen that the chemical actions in thetank take place under reduced pressure, which condition I find in practice adds very greatly to the rapidity of the operation and is an important factor in the practical operation of recovering the metal from the ore.

I/Vhat I claim as my invention is 1. The combination substantially as described in an apparatus for recovering gold and silver by the cyanid process, of a pulpcontaining vat or tank, an inlet at the bottom of the tank-opening in position to cause gas when introduced in'sufiicient quantity and under sufficient head to thoroughly agitate any pulp contained therein, connections leading from the outside atmosphere to said inlet, a I/Voulfe bottle interposed in such connections and adapted to supply the entering air with a gas of the halogen group, an outlet from said pulp-containing tank connected to the upper part thereof, a hydraulic exhaustpump connected to said outlet and an absorption tank or vat interposed in the connection between the tank and the exhaustpump said pump being adapted to produce by exhaustion a flow of air through the Woulfe bottle and into the tank in suflicient amount to thoroughly agitate the pulp, as and for the purpose described.

2. In an apparatus for recovering gold and silver from ores, the combination substantially as described, of a closed tank adapted to hold a metal-bearing pulp and having an inlet at the bottom thereof, pipes or connections leading from the outside atmosphere to said inlet, a VVoulfe bottle and a heater interposed in said connections, an outlet from the top of said tank and a hydraulic exhaustpump and an algWtank connected to said outlet, the -sorption-tank being interposed between the outlet and the pump, as and for the purpose described.

Signed at Philadelphia, in the county of Philadelphia and State of Pennsylvania, this 30th day of April, A. D. 1904:.

CRAIG RITCHIE ARNOLD.

Witnesses:

J. W. H. UNDERWOOD, M. G. GARLAND.

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