US1447140A - Process of extracting precious metals - Google Patents

Description

Feb. 27, 1923.

WITNESSES;

c. c. MCBRIDE PROCESS OF EXTRACTING PRECIOUS METALS Filed Apr.

III/II III/III! II/I INVENTOR ATTO RN EY Patented Feb. 27, 1923.

CHARLES C. MGBRIDE, OF SANGER, CALIFORNIA.

PROCESS OF EXTRACTING PRECIOUS METALS.

Application filed April 23, 1921. Serial No. 463,995.

T 0 all whom it may concern:

Be it known that I, CHARLES C. MCBRIDE, a citizen of the United States, residing at Sanger, in the county of Fresno and State of California, have invented certain new and useful Improvements in Processes of Extracting Precious Metals, of which the following is a specification.

The present invention relates to the recovery of precious metals, such as gold, platinum and silver, from ores containing the same, and the process has been shown to give excellent results in the treatment of sea sands containing such precious metals, such sea sands being found native in a number of places. a i

The process consists essentially in agitating the said sands, or other ores carrying the said metals, preferably after crushing to about the size of ordinary sea: sand, while the said ore sands are suspended in a solution of sodium chloride, preferably of about one to three per cent) strength, while passing a current of electricity from an insoluble anode in said liquor to an amalgamated lead plate in said liquor. For ordinary purposes plain sea water is an excellent material to use as an electrolyte and the agitation can easily be efi'ected by passing the ore or sand from one end to the other of a rotary cylinder having an amalgamated lead lining, suitably projecting ribs being provided for advancing the ore or sand from one end of said. cylinder to the other.

The accompanying drawing represents the vertical section of an approved form of apparatus for carrying out the process. In said drawing 10 represents a tank made out of any suitable material not readily acted upon by the materials used in the process. Extending lengthwise of this tank is a drum 11, made of lead, the interior of which is coated with mercury. Instead of making the cylinder of lead it may be made of wood or like material having a lead lining. '12 represents a helical ridge or vein, which causes the ore to progress through the cylinder when this cylinder is rotated for example by the pulley 13. At 14 is shown a hopper through which the sand or crushed ore is dropped into the receptacle. The cylinder being rotated in the direction of the arrow 15, the ore will be picked up by the projecting end of the cylinder and fed in the direction of the arrow.

Located at any suitable point in the receptacle l0 belowthe normal liquor level therein (for example 16) is an insoluble anode 17. The current lead 18 is connected to the negative end of the electric circuit this in turn being connected at 19 to .the lead cylinder.

Located at the outlet end of the cylinder is a sump 20 into which the tailings are dumped from which they are removed by an inclined screw conveyor 21, or otherwise.

. It isl-adviswble to feed the ore through 14 at such a rate as to maintain a quantity of ore as shown at 22 in the inlet end of the electrolytic vat.

As the cylinder revolves a portion of the pulp or sand is picked up and carried through the cylinder and deposited in the sump 20 from which it is removed to waste. In this manner the ore material is brought into contact with the amalgamated lead lining of the cylinder; The cylinder is so partitioned that a narrow path is made conforming to the circumference of the cylinder and travelling spirally from the intake end to the discharge end. During the passage of the pulp or sand through the cylinder it comes into repeated contact with the amalgamated lead lining of the cyl-v inder and the current of electricity passing from the insoluble anode tothe lead lining causes the gold, silver or platinum (or mixtures of these) to be carried to and deposited upon the amalgamated lead plate. The electrolytic action is assisted by both gravity and centrifugal force, whereby the removal of the precious metals from the ore is extremely rapid and complete. In addition to the above mentioned physical advantages, more or less metallic sodium is deposited upon the mercury, forming a sodium amalgam which assists in the removal of the precious metal from the ores. Also the low conductivity of the metallic lead increasesthe capillarity of the "mercury by contact.

In regard to the amalgamated lead plate, lead is selected particularly because lead is slightly less resistant electrically and is more positive in the electromotive series than is mercury, this increasing the clarity of the mercury by contact.

For supporting the cylinder suitable brackets as shown at 25 may be provided, these being carried by shafts 26 passing through stufiing boxes 27 and through suit ablejom'nal beaes 28.

ramneo In addition to the helical flange 12, the cylinder may have a spiral construction as indicated at the left hand end of the figure, the portion of the cylinder 29 being lapped inside of theuportion 30. This gives muchmore of a tumbling action to the ore in pass ing through the cylinder or conveyor.

I claim: A process of extracting precious metal from ore, which comprises continuously agitating a non-progressing solution containing essentially an alkali metal chloride while.

agitating and tumbling an ore of a sand-like consistency in said solution, and While causing said ore to progress from one end of the solution to the other, While passing an electrolytic current through said mixture,

J from an insoluble anode to an amalgamated lead cathode.

In testimony whereof I afix my signature. 20

CHARLES C. MCBRIDE.

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