US247972A - Process of preparing - Google Patents

Description

(No Model.) v

R. R. WAITZ.

PROCESS 0E PREPARING REFRAGIORY ORES FOR AMALGAMATION. No. 247,972. Patented ct. 4,1881.

X4320 Til/6,00.

. [PROM/r6 nJma/cz. U r I- UNITED STATES.

PATENT OFFICE. 1

ROBERT R. WAITZ, OF ROSITA, COLORADO.

PROCESS OF PREPARING REFRACTORY ORES FOR AMALGAMATION.

SPECIFICATION forming part of Letters Patent No. 247,972, dated October 4, 1881. Application filed September 9, 1881. (No model.)

declare the following to be a full, clear, and

.' exact description of theinvention,such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawing, and to letters or figures of reference marked thereon, which form a part ofthis specification.

The object of my invention is to furnish a process for treating refractory anriferous and argentiferous ores, by means of which the base metals contained in said ores are thoroughly and quickly converted into insoluble oxides, and all volatile matters decomposed and expelled from the furnace. I attain the results stated by heating the pulverized ore in a scientific manner in a furnaee or chamber from which atmospheric air is excluded, as will hereinafter he more fully set forth, and then indicated in the claim.

In carrying out my process I pnlveri'ze or comminute the ore containing the precious metals, and add thereto, before or after its introduction into a furnace or heating-chamber, any well-known oxygenated agent or .substance-such as dioxide of manganese, chlorate of potassium, or ferric oxide. These substances may be used singly, or two of the same or all three may be combined. The proportions in which they are used depends altogether upon circumstances or the character of the ores, because the latter frequently contain the aforesaid substances. It is an essential requisite that no sulphates shall be presentin the ore when the same is undergoing the process of amalgamation, and for this reason I also add to the ore, before or after its introduction into thefurnace, an agent or substance which will serve to decompose the sulphates formedparticularly sulphate of copper. In certain instances the carbonic-acid gas evolved by the combustion of fuel in the fire-chamber of the furnace will serve to accomplish the result stated. When. copper pyrites are being treated I preferably add thereto a sufficient quantity of the well-known reagent-carbonate of ammonium-for decomposiu g sulphates. In this instance the latter are converted into volatile sulphate of ammonia, which passes 01f.

It has already been stated that the invention consists chiefly in a scientific manner of heating the ores, and I will now proceed to fully describe the same, reference being bad to the accompanying drawing, which illus- 6o trates a furnace preferably employed for carrying out my process.

The pulverized ore is fed into a closed flue or chamber, andis conducted or passed through the same in the form of a thin stratum or 6 body, whichis in constant motion from the inlet to the outlet openings. In the form of furnace illustrated in the drawing the ore moves by its own gravity through aninclined flue or chamber, and is discharged upon a hori- 7o zontal hearth or sole located in juxtaposition to the grate or fire chamber. It will be manifest, however, that the ore can be moved by mechanical means through a horizontal flue or chamber. The flames and heated gases issuing 7 5 from the fire or grate chamber pass through the flue or ore-treating chamber and obviously cause an excess of oxygen to'evolve from the oxygenated substances contained in the ore. The thin stratum or body of ore will enable this result to take place in an expeditious and perfect manner, because the sheet of flame is brought into intimate contact with the ore.

It is necessary to the proper heating orroasting of ores that the same be heated gradually, 8 5 so as to obviate the fusion of sulphides at the outset and prevent the formation of a matte troublesome to roast. In my process the ac- 1 tion of the heat is, as just stated, because the ore is constantly moving from the feed-hopper o farthest from the fire-chamber to the disch argepassage in proximity to the latter.

The liberation of oxygenby heat in the manner above indicated will not only serve to effeet the perfect oxidation of the base metals 5 without. the aid of an air-blast or current of atmospheric air, but will also tend to supply the necessary amount of oxygen to the firechamber for supporting the combustion of fuel therein. 10:)

It will be obvious that the descending or moving body of ore will effect a back action of the oxygen existing near the fire-chamber, and force the same into the latter; hence it is possible to support combustion with closed furnace-doors, there being no admission whatever of atmospheric air.

h'ly process is specially designed for treating refractory ores of precious metals, because I am able to perform the heating operation with a small consumption of fuel and in a comparatively brief period of timeone to two hours. The roasted ore passing from the furnace contains the precious metals in a pure metallic state, and as all base metals have been converted into insoluble oxides and the sulphates decomposed, the process of amalgamation with mercury can be performed in a thorough and expeditious manner.

I am aware that it is not new to add oxygenated substances to ores while undergoing the roasting operation in a furnace having means for admitting atmospheric air, and devoid of devices for propelling the ore. It has also been proposed to roast ores, mixed with oxidizing agents, in a retort or closed cylinder revolvingjn afirechamber, and having a steam-jet pipe leading into said retort.

I am also aware that ore has has been passed through a flue or roasting-chamber in the form of a thin stream or stratum moving constantly from inlet to outlet, and subjected to the oxidizing action of a current of atmospheric air and heated gases.

I disclaim the various steps of ny process separately considered, and confine myself to the combination ofsteps herein set forth, which promise a success much surer and a roasting far better and expeditious than by any other process heretofore proposed.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent,is

The process of desulphurizing and oxidizing refractory auriferousand argentiferous ores, consisting in subjecting a thin body or stratum of ore, moving constantly through a closed chamber from which air is excluded, to the direct contact of a caloric current or sheet of flame, and of oxygen, evolved by the decomposition of oxygenated agents contained in the ore, through the medium of heat, the oxygen so obtained, in addition to its oxidizing action, serving to support combustion in the ore-chamber, and in a firechamber communicating directly with the latter, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

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