US1352832A - Process for extracting precious metals - Google Patents

Description

A c. P. PRIEST.' PPOCESS FOR- EXTRACTING PRECIOUS METALS.

APPLICMHQN FILED AuG.2|. |919. l 1,352,832. l A Pafentedsept.14,1920.-v

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PATENT oFFicE.

CHARLES P. PRIEST, OF PHILADELPHIA, PENNSYLVANIA.

PROCESS FOR EXTRACTING rILIREIJIGUS METALS.

To all whom t may concern:

Be it known that I, CHARLES. P. PRIEST, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, lhave invented certain new and useful Improvements 1n AProcesses for Extracting Precious Metals, of

mator or sluice partly by the electrolytic decomposition of water passing therethrough and partly by the action of the water on the metallic sodium formed by the electrolytic decomposition ofthe sodium chlorid introduced with the slime The function of the hydrogen which is .of course in a nascent state, is to remove objectionable oxids and sulfurous coatings from the particles of precious metals to facilitate their amalgamay tion with the mercury.

An important object is the provision of a process which involves continually passing the slime and solutions over an amalga-` mated copper plate forming one element of' an electrolyiing bath whereby the process will be continuous and rapid. i

It is possible t6 carry out the process with different varieties of apparatus, though for purposes of illustration I have shown a satisfactory apparatus for the purpose in the accompanying drawing which shows a somewhat diagrammatic elevation.y i

Inlcarrying out my process, the sand or ore is mixed with sodiumlchlorid solution and ground to the proper ineness, in some instances to as line as 200 mesh. Solutions of hydrogen and mercury salt, such as mercury bichlorid, are then added to the slime and the whole is thoroughly `I'nixed and then 'l flowed through an electrolyzing sluice in which is provided a copper plate amalgamated with mercury upon which the particles of precious metal will be deposited.

In the drawing, the numeral lO designates Specification of Letters Patent. Patented Sept, 14, 1920, Application filed August 21, 1919. Serial No. 318,947. i

an ore grinder of conventional type driven by suitable means andhaving an inlet end' ll into which the ore or sand is fed and'into which is suppliedkthe sodium chlorid or common salt solution. Disposed in position to receive the ground material discharged from the grinder l0 is a mixing device l2 of any ordinary construction and of either the horizontal or vertical type. whrereby the slime or pulp from the grinder enters the mixer there is introduced by any At the point 13 suitable means, a solution of mercury bichlorid and a water solution of hydrogen. The purpose of introducing the hydrogen, which is in the molecular state, is to saturate the slime or pulp with hydrogen for a purpose to be described. The slime or pulp, after being thoroughly mixed with the solution in the mixer 12, is'discharged into the sluice 14 ywithin which is disposed a plurality of lswinging anode plates l5 connected in an electric circuit with a suitable cathode plate 16.

In carrying out the process the sodiumv chlorid in solution is broken up int-o its con*` stituents, metallic sodium and chlorin, which being in the nascent state, are highlyactive. The chlorin acts as a cleansing agent and assists in removing objectionable coatings from thev particles ofprecious metal. The mercury bichlorid is broken up into metallic mercury and chlorin and the metallic mercury is of course deposited upon the plates. The nascent metallic sodium formed by the breaking up of the salt solution unites with the metallic mercury to form mercury and sodium amalgam which has a great affinity for the precious metals.v Themet'allic sodium furthermore is acted upon bythe water of the solution and forms sodium hydroxid and hydrogen gas. Sodium hydroxid is a cleansing agent and will therefore act ad-.

vantageously upon the particles of precious metals. The hydrogen liberated isin a nascent state and consequently highly active and will go to the mercury and sodium amalgam and greatly increase the activity thereof so that as the particles of precious metal passing through the sluice come in contact with the plates they will be deposited thercon/ and amalgamate therewith. It might .also be stated that some of the hydrogen will assist in removing oXids from the precious metals and make them clean and bright to facilitate their amalgamation.

L The preliminary saturation of the solution with hydrogen prevents the hydrogen liberated from being absorbed.

The combined use of the three powerful amalgamating agents, mercury, sodium and*` hydrogen forms a perfect amalgam which is soft,..smooth, elastic, tenacious, yet plastic and which willnot crumble. The hydrogensodium-mercury amalgam is chemicallypure and has such an affinity for precious metals that the particles of the latter will be attracted even under the most adverse conditions, such as'the presence of silicious, arsenical, greasy, sulfurous or rusty coatings.

I claim 1. A process of extracting precious metals from ores or sands consisting in grinding the ores or sands in a solution of a sodium compound, then mixing with a hydrogen solution and a mercury compound solution, and then electrolyzing the slime whereby to effeet amalgamation.

2. A process for the extraction and recovery of precious metals from ores `or sands consisting in grinding the ores or sands in a solutlon of sodium chlorid, then adding .hydrogen and a solution of mercury bichlorid, and subsequently effecting amalgamation by electrolysis.

In testimony whereof I hereto affix my signature.

CHARLES P. PRIEST. l

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