US664060A - Process of extracting precious metals from their ores. - Google Patents

Description

No. 664,060. 4 Patented Dec. l 8, I900.

' J P. SCHUCH", 1R.

PROCESS, OF EXTBACTING .PREGIOUSJVIETALS FROM THEIR URES. (Application fl 1ed Decv27, 1898.)

(No Model.)

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UNITED STATES PATENT FFICE.

JOHN PHILIP SOHUOH, JR., OF ORIPPLE GREEK, COLORADO.

PROCESS OF EXTRACTING PRECIOUS METALS FROM THElR ORES.

SPECIFICATION forming part of Letters Patent No. 664,060, dated December 18, 1900.

Application filed December 27, 1898. Serial No. 700,405. (No specimens.)

To all whom it may concern.-

Be it known that 1, JOHN PHILIP SoHUcH, Jr., a citizen of the United States, residing at Cripple Creek, in the county of El Paso and State of Colorado, have invented a new and useful Process of Extracting Precious Metals from Their Ores, of which the following is a specification.

This invention relates to an improved process of extracting precious metals from their ores; and it has for one object to provide for treating metal-bearing ores by the use of oyanogen containing solvents in a novel and efficient manner, whereby a much larger percentage of the value of the ores may be saved than has been heretofore possible by the ordinary cyanid process.

Heretofore in treating gold-bearing ores by the common cyanid process the ore is first crushed, dried, and rolled to a proper degree of fineness, and that which requires roasting is then conveyed to the roasters, while the oxidized ore, which does not require roasting, is delivered to the bin or receptacle therefor. After the portion of the ore to be roasted has passed through this step of the process the same is conveyed to the cooling-room before being deposited in the bin or receptacle referred to, which contains the ore requiring no roasting. All of the ore is then removed by manual labor into the ordinary stationary cyahid-tanks, and after these tanks are filled with the ore the cyanid solution is introduced therein. In this process the filled cyanid-tanks,with the solution and ore therein, are permitted to remain filledand unmolested for a suflicient length of time for the solution to act on the ore, after which the gold-bearing solution is drawn off and allowed to flow to the precipitation-room, while the tailings in the tank are then washed with water and shoveled out, or sluiced out when this is possible. In carrying out this old cyanid process the percentage extracted rarely exceeds ninety per cent. of the ore value, whereas the present invention provides a process for saving a larger per cent. of the ore value, while at the same time permitting of the mixing together of various grades of ore with a cyanid solution, so as to make one even grade out of ores of various values.

A further object of the invention is to provide a process which involves the thorough aeration of the ore and solution during mixing, whereby the oxygen of the air may be utilized to assist in dissolving the gold in the ore.

The process contemplated by the present invention may be carried out by any practical means which would involve the mixing of the cyanid solution with the ore prior to its introduction into the lixiviation-tanks, as this is one of the leading objects of the invention namely, to overcome the objection to first mixing the ore with the cyanid solution directly in such tanks. However, the preferred manner of carrying out the process is in connection with the improved mixing-machine disclosed in my contemporaneously-pending application, Serial No. 697,780.

The preferred form of mixing machine or apparatus with which the process is carried out is shown in the accompanying drawing, in which the figure is a sectional view thereof.

The mixing-machine illustrated in the drawing essentially consists of an upright tank 1 of the required capacity, which is entirely open at the upper end thereof and has connected with the bottom a solution drainagepipe 9, which leads to the usual precipitationboxes in the precipitation-room, whereby the gold-bearing solution which percolates to the main bottom of the tank may be conveyed to the precipitation-room to provide for precipitating the precious metal from the solution.

The said tank 1 has fitted within the bottom thereof a strainer 10, through which the goldbearing solution must pass before reaching the drainage-pipe 9, and serves to collect and retain sand, slime, and other impurities contained in the ore-or evolved by the chemical action of the cyanid solution thereon. The said strainer 10 therefore effects a separation between the gold-bearing solution and the ore pulp or slush which is mixed with more or less of the solution, as the result of the mixing operation within the mixing-tank, and to provide for carrying off said ore pulp or slush which does not penetrate the strainer the tank 1 has fitted thereto above the plane of the strainer an ore-discharge spout 16, through which the ore pulp or slush, which is necessarily saturated with more or less of the cyanid solution, passes and is delivered into the lixiviation-tanks.

To provide for an intimate mixing of the ore and cyanid solution within the mixingtank, the latter has arranged therein a revoluble agitator 18, and a solution-supply pipe 40 is fitted in one side of the tank near the top thereof to provide fordelivering into the same a constant stream of the cyanid solution.

Other details of the mixing-machine which are not essential to the present invention are fully described in the other application herein referred to.

Now in the ordinary process of treating gold-bearing ores, as explained in the statement of invention, the oxidized ore which has been crushed and reduced to a propel-degree of fineness does not need roasting, while other portions of the ore must be subjected to the roasting step. In the present invention, however, instead of allowing the roasted ore to become entirely cold in the cooling-room the same is conveyed or delivered by a conveyer or any suitable means through a feed-chute 38 directly into the open upper end of the mixing-tank 1 while the ore is still in a warm condition. At the same time a stream of the oxidized ore is delivered from this receptacle by any suitable means, preferably through a feed-chute 39, into the open upper end of the mixing-tank. While the separate portions of the ore are thus being delivered into the mixing-tank a constant stream of the cyanid solution is also being delivered into the tank by the solution-supply pipe 40, previously referred to, and as the agitator 18 is constantly revolved in the tank the entire mass of ore is intimately mixed with the solution, thereby insuring an even and uniform extraction of the precious metals from their ores. As previously explained, the gold-bearing cyanid solution passes through the strainer in the bottom of the tank and into the solution-drainage pipe 9, through which it is carried to the precipitation-room, while the ore slush or pulp, mixed with the solution, discharges through the spout 16 and is delivered to the lixiviation-tanks. the ore is thoroughly mixed with the cyanid solution prior to its introduction into the lixiviation-tanks.

In carrying out the invention it is necessary that the ore and cyanid solution while being mixed together must be thoroughly aerated or charged with air, so that the oxygen from the air will assist in dissolving the gold in the ore. By using the cyanid solution instead of water on the ore at the stampmills it is unnecessary to charge the mixture within the mixing-tank with air. In fact, the free-gold ores or oxidized ores can be treated through the stamp-mill by using the cyanid solution instead of water, and the solution, carrying the fine ore with it, may be either run over amalgainating-plates directly to the cyanid-tanks or to the mixing-tank, herein described; but in either event it will be seen that by mixing the cyanid solution with the ore directly at the stamp-mill the mixture So it will be observed that will be necessarily exposed to the air, so that the oxygen in the air will be free to assist in dissolving the gold in solution. However, in the preferred way of carrying out the invention it is necessary to charge the mixture within the mixing-tank with air, and to accomplish this the tank is provided, preferably near the top thereof, with an exterior annular air-blast pipe 41, having a plurality of dependent jet-pipes 42, opening into the tank near the bottom thereof, so as to inject air into the mixture of ore and solution during the mixing thereof by the agitator.

In connection with the aeration of the ore and cyanid solution the best results are accomplished by using hot air. The use of hot air is specially practical in connection with the jet-pipes of the mixing-tank, and heated air should always be forced into the ore within the mixing-tank when the ore is cold or not roasted.

Another feature of importance in carrying out the process is to use the cyanid solution quite warm, and a number of expedients may be resorted to for the purpose of maintaining the solution at a proper temperature. As the ore which is introduced into the tank 1 of the mixing-machine is used while in a Warm condition, the same will necessarily serve to keep the cyanid solution warm, so that ordinarily in connection with the mixing-machine it will not require supplemental means for heating up the cyanid solution; but as it maybe necessary at times to resort to supplemental means for heating the solution before introducing it into the mixing-tank one way to accomplish this result is illustrated in the draw ing, where the solution -supply pipe 40 is shown leading from a storage tank or reservoir 46 for the cyanid solution. This storage tank or reservoir 46 may have arranged therein a heating-coil 47 of piping, the terminals of which coil are connected with any suitable supply for steam or hot air, whereby a circulation of steam or hot air may be maintained in the coil, thus insuring the thorough heating up of the cyanid solution before it is delivered through the supply pipe or pipes to the point of use. While the interior heatingcoil within the storage tank or reservoir for the cyanid solution will accomplish the desired result, it will be understood that an exterior coil or any extraneous means for heating up the solution may be utilized for the same purpose.

In the practical operation of the process it has been found that the best results are accomplished by heating the air when the same is introduced through the jet-pipes 42 into the mixture, inasmuch as air in a heated condition has been proven to be very elfect-ive to insure the activeattacking and dissolving of the gold by the cyanid solution.

It has already been explained that ordinarily a separate heating of the solution which is used in the mixing-tank is not necessary; but this is always necessary when the cyanid IIO solution is used at the stamp-mill or in any wet crushing-machine instead of water, which operation dispenses with the necessity of introducin g air into the mixture within the mixing-tank, as previously explained.

It will of course be understood that when the cyanid solution is used in a warm condition directly at the stamp-mill or'in any wet crushing-machine said cyanid solution may be heated up in' the storage tank or reservoir in the same manner illustrated in the figure of the drawing, the essential feature of this particular processresiding in having the. solution in a thoroughly-heated condition, yet below the pointof boiling or evaporation.

,While the essential features of the process have already been indicated, it will be understood that in carrying out the same quicksilver; can be used at any point where free gold is present -such, for instance, as on plates in the stamp-mil] or on any wet crushing-machine, or alsoon specially-constructed pans or prepared plates within the mixingmachine herein referred toso as to insure the collecting of all coarse free gold.

Incarrying out the herein-described process in the precipitation of the goldfrom the cyanid solution any method may be used, such as the zinc-shavings method, electrolysis, or the charcoal method, 85c.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is-= A method of extracting precious metals from their ores, which consists in combining the crushed ore with a cyanid solution while both are in a warm condition, mechanically mixing the ore and solution by agitation simultaneously with the commingling thereof, charging the mixture during the agitation with hot air, and finally separating the ore and slush or pulp from the metal in solution, substantially as set forth.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses. t

' JOHN PHILIP SOHUCH, JR.

Witnesses:

F. H. NoLTE, A. B. OLSON.

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