US133927A - Improvement in smelting gold, silver, and other ores - Google Patents

Description

. K2Sheets--SheetL jw. o. nAv|s.

Smelting Gold. Silver, and other Oras.

No. 133,927.5 Patented Dec.17,1872.

l lofi 2 Sheets--Sheet 2. w. uY nAvls.

Smelting Gold. Silver, and other Oras.

No.133,927. Patented Dec.17,1872.

' Toall aber yitl may cncern.-

1 it known that I, WILLIAM O. DAVIS, of Pittsburgin the county of Allegheny and State of Pennsylvania, have invented a new and usefullmprovement in the Smelting of Gold, SilvYer, and other Orcs; and I do hereby declare n the following to bea full, clear, and exact de- 'l "scription thereof, reference being had to the accompanying drawing, in which- Figure 1 is lafront elevation of a single smelting-chamber j Fig. 2 is a sectional elevation through the axis vof the smeltin g chamber; Fig. '3 is a horizontal section through ai w of 15j and Fig. 4 is a vertical section through the' center of a smelting -furnace or nest 'of smeltingchambers. n In the drawing like letters of reference are used to denote similar parts. y

l In the process of smeltin g the precious met- `als as ordinarily practiced there is a great loss caused by thel'oxidatien of those metals, and great` difficulty,l experienced in the desulphurizin g ofthose ores which contain sulphur, and even in those improved furnaces heretofore .nsedwhich are best adapted to overcome these evils the process is rendered extremelycostly by the rapid destruction of the smelting-chambers, owingto the high heat requisite to the conduct of the process, together with the introduction of the blast into the sm elting-chamber. It is the purpose of my invention greatly lto reduce the loss by oxidation, to provide an effectual and ready mode of desulphurization, and to provide la furnace lin which any of the smelt-v ing-pots can be easily renewed from timeto time without arresting the process in the other yparts of the furnace.

First, as to the waste by oxidation: Ipropose n `in a great measure to obviate this diiiiculty by smelting the precious metals in a furnace so vllnosph'eric air vand gases from the furnace to the melted metals in such degree as to cause any lserious loss from` that cause; and to this end I so construct ,my smelting-chamber as to .dispense with the use of tuyeres and blasts `of air which are ordinarily employed; second, in @hier `readily to desulphurize the ores, where this is necessary, I'employ, as a part of the charge, iron sponge, which is metallic iron nearly from oxygen and carbon and in a constructedas top r'event the access of the at-j..

PATENT OFFICE.

KWILLIAM o. DAVIS, or PirrsBUnc, PENNSYLVANIA.

' mPR'cvEMENT IN sMEL-rmc com, SILVER, AND oTHER oREs.

A Spcincati'on forming part of Letters Patent No. 133,927, dated December 17,1872.

light porous condition, which, when heated awayfrom the presence of oxygen, has a stron gl affinity for sulphur, and will free the eres of gold, silver, and leadfrom that substance; and

-such iron sponge may, in some cases, be adl moved and replaced without materially letting down the heat or stopping the process in the v,other pots of the set.

A. To enable others skilled in the art to make and use my invention, I will proceed to de scribe more in detail the apparatus and process which I have invented.

In the drawing, Figure 1,*A is the 'smeltin gchamber, built of fire-brick or other refractory material. It inay be convenientlylmade of cylindrical shape. In the center `is the smelting! pot B, made of like suitable material. It is preferably an upright cylinder having a rounded bottom and a contracted' inverted funnel-V shaped top, furnished at top with a damper, C, which is ordinarily closed, butis raised whenever necessary to allow the escape of the sulphurous vapors, gases, &c. The chamber A is so constructed, as shown in the drawing, as to have a space, D, all around the sides of the central smelting-pot B, excepting at the charginglholeE near the top and at the opening for removing the slag and tapping oif-the base bullion, which is at the bottom of the smeltf ing-pot. The smelting-chamber A is heated by a furnace placed back of the smelting-chamber A, and which may be of any desired con-` struction adapted to furnishing the requisite degree of heat. A Siemens furnace would answer an excellent purpose. The heated air and gases from the furnace enter the smeltingf; chamber at the opening G, at the back and just below the bottoni of the smelting-pot B, and, passing around and enveloping the pot, pass away, at the ue H at the bottom of the smelting-chamber, tothe chimneys I I on each side. Below the kopening F is the tap-holeJc, which opens into the smelting-pot at its lowest point so aste drain off all the melted bullion. The

off. These openings are to be kept closed during the process of smelting by firebrickdoors and stopper, which are removed when necessary. l

The mode of using this smeltin g apparatus is to insert the charge, consisting ofthe ore to be smelted, with the proper flux or fluxes, and iron sponge, if desired, at the charge-hole E, which may then be closed and luted with clay. The slag-hole F is closed by a brick of suitable shape, and the tap-hole K by a plug, while the process of smelting is carried on. The furnace which supplies the heat may be furnished v. ith a blast, if necessary, and dampers to regulate and control the heat; but no air from outside nor gases from the furnace have any access to the interior of the smelting-pot, and, the heat being uniformly distributed all around the smelting-pot, it is not liable to the rapid destruction caused bythe blowing in of blasts of air through tuyeres into the smelting-chamber, as is ordinarily practiced.

As the metal (gold or silver, or silver mixed with lead, as the case may be) is smelted it vruns down into the bottom of the smeltingpot B, and the melted slag floats on the top. The atmosphere and gases from the furnace being excluded, there is little or no oxidation, and therefore very little if any dross is formed.

At the proper time the brick is withdrawn from the slag-hole F and the molten slag run off.' This brick is speedily replaced so as to allow as little air as possible to enter, and then the tap-hole K is opened and the base bullion drawn oft'.

When sulphur is present in the ores there is added to the charge a suiiicient quantity (depending on the amount of sulphur in the ore) of iron sponge-an article which is obtain ed in great purity by the process patented by Thomas S. Blair on May 21,1872. This presence of the iron sponge has the effect of removing the sulphur from its combination with the ores of gold or silver; and, owing to the highly-sensitive quality of the sponge when heated, it also absorbs any oxygen which may be present in the ore or in the charge, or which may accidentally enter the smelting-chamber, and thus elfects a great saving in the process of smelting the precious metals, producing a much larger percentage of yield in base bullion.

Fig. 4 represents afurnace for smelting ores in which any convenient number of smeltingpots for carrying on my process may be used at the same time, and by a single re. The furnace is a chamber, circular or of other suitable form, of brick-work L, covered by a domeshaped roof, and furnished with a suitable fire-chamber below or at one side, as may be preferred. As thev construction and arrangement of the fire-bed may be varied at pleasure, it is not shown in the drawing. Around this circular chamber L is a series of openings at regular intervals, into which are inserted the smelting-pots M M, &c. These pots are placed within the chamber L sufficiently far from its inner wall to have a space all around the pot, excepting at the projecting parts N and O of the pot, the former of which forms the charging-aperture and the latter the slag-hole. The space in the circular chamber L left for the insertion of the pots between the pillars which support the dome-shaped roof is bricked up Y when the pot is set so as to inclose the furnace and retain the heat. This part of the brickwork is torn down whenever a pot has to be removed, to be replaced by another. At the top of each pot is a cylindrical tunnel-head, l?, which projects out through the roof of the chamber, the space for inserting the pots and the removable brick-work extending to that point or the tuimel-heads may be made separate and inserted through the top of the dome. The top of the tunnel-head P is covered by a damper, like the smeltng-pot shown in Figs. 1 and 2.

The mode of using these pots is precisely similar to that already described. The lire in the furnace is kept up at all times, and the charging of the several pots is done in rotation, so that the hands may be kept continually employed, and one set of hands can attend to several pots.

Whenever one of these pots becomes so far Worn out as to require renewal, the brick-work filling the space between the pillars of the furnace-chamber L is removed, and the old pot is rapidly withdrawn, and a new pot, previously heated in a small detached oven used for that purpose, is run into place on an iron carriage, and the hole is rapidly bricked up again. This operation is readily performed, the whole change being effected, in ordinary cases, in the space of an hour, more or less.

The apparatus and process hereinbefore described may be applied to the smelting of copper and lead ores.

On account of the rapidity with which this process can be carried on, and the small percentage of loss, I am enabled to smelt many ores with a remunerative yield which have heretofore been thrown away as waste material.

Having ths described my improvement in the smelting of precious metals, what 1 claim as my invention, and desire to secure by Letters Patent, is-- 1. The process of smelting the ores of gold, silver, &c., in furnaces, constructed substantially as hereinbefore described, so as to exclude the atmospheric air and products of combustion of the furnace from the interior of the smelting-chamber, substantially as and for the purposes hereinbefore described. v

2. The combination of iron-sponge in a close smelting-pot with the ore and suitable fluxes as a charge for smelting gold, silver, lead, and other ores, substantially as and for the purposes hereinbefore described.

3. A smelting-chamber consisting of a pot,

eul'strueted 'substantially as hereinbefore deenveloping the pots, as and for the purposes bed, 'so sarto exclude the atmospheric air hereinbefore set forth.

thekproducts of combustion of the fur- In testimony whereof I, the said WILLIAM from its interior, and surrounded by a O. DAVIS, have hereunto set my hand.

uiting-chamber, substantially as and for the WILLIAM O. DAVIS. el hereinbefore described. p

l The arrangement of two ormore smeiting- Witnesses: :tgeonstructed substantially as described W. N. PAX'ION, fthe preceding claim, in a. furnaeechamber, Gr. H. CHRISTY.

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