USRE8266E - Chaeles stetefeldt - Google Patents

Description

C. STETBPELDT. Assignor, by mesne assignments, to STETEFELDT FURNAeE Go.

Ore-Roasting Furnace.

Reissued MIay 28,1878.

IJV VENTUR- UNrrnn: STATES PATENT OFFICE.

CHARLES STETEFELDT, oF SAN FRANCISCO, ClAL'nronNiA,` ASSICNCR, BY

MESNE ASSIGNMENTS, To STETEFELDT FUBNACE CoMrAiW.

lMPR-OVMENT IIN ORE-ROASTING .FURNACEy-S.'

Speclcation'forming part of Letters Patent o. 72,931, dated December 31,1867; Reissue No. 3,807, dated January 25, 1870; Reissue No. 8,165,- dated April 9, 1878; Reissue No. 8,266, dated May 28, 1875 application iiled May 23, 187B.

To all whom it may Be it known that I, CHARLES STETEFELDT,

y of the city and county of San Francisco, State of California, have invented Improvements in Furnaces for Chloridizing Silver Ores; and I do hereby declare the following to be a full,

clear, and exact description thereof, reference being had to the accompanying drawings.

My inventionis interrdedto provide improvements in furnaces for chloridizin g silver ores preparatory to amalgamation.

This furnace is constructed with a shaft,

heated by a nre-place, the iiames 'of which enter near its bottom through which the pulverized ore, mixed with salt, drops, retarded chlorine, hydrochloric acid, and volatile chlo.

rides, which continue to emanate yfrom the roasted ore accumulated at the bottom ofthe shaft. A ilue near the top of the shaft allows the gases to pass into a series of dust-chambers connected with a chimney.

As the ore has to be pulverized very line preparatory to amalgamation or other 'processes of extraction, a part of it will be necessarily carried by the draft directly through the flue into the dust-chambers, and is consequently either entirely raw, or, at least, im; perfectly roasted, not having been exposed to a sufficient degree of heat.

g' To effect a perfect roasting and chlorination of this part of the ore, an auxiliary lire-place is connected with the flue through which the dust passes, and, as the ore is so very ne,

v and in an atmosphere of chloridizing-gases,

its chlorination is completed in a moment in passing the llame from the auxiliary lireplace. v i To more fully illustrate and describe my furnace, reference isl had to the accompanying drawings and` letters marked thereon, of whichl Y Figure 1 is a section taken through P P. Fig. 2 is a section taken through M M. Fig. 3 is a section taken Ythrough H H. Fig. 4 is a section taken through O O. l,

B represents the perpendicular shaft o f the furnace, covered at the top with an iron plate, E, having slitsl a a a, through which the pu1- verized ore is continuously fed by machinery. C is a fire-place, near the lower end of .the shaft, from which the llames and gases pass up the shaft B, and through the ue D and H' into the dust-chambers I I. M' is a discharge-door, through whichY the roasted oreyis drawn out which accumulates in the lower part L' of the shaft B.' J is the auxiliary lire-place, covered by the arch K, and opening into the flue H'L Here -the ore is roasted which is too fine to fall down the` shaft B. n

The operation of my furnace is as follows -to wit: Fire is made in the lire-places C an J, and as soon as the furnace is hot the feeding machinery is put in motion, and the ore is fed in a continuous stream.` The only attention which the furnace requires is the keeping up of a regular roasting heat. The roasted ore is allowed to accumulate at the bottom of the shaft nearly up to the fire-bridge4 of the lire-place G. This is very important, as a great amount of chlorine, hydrochloric acid, and volatile chlorides emanate from the charge and act upon the falling ore. The roasted ore is discharged through the floor M'. The ore which is roasted in the flue H' by the heat from the auxiliary fire-place J and deposited' in the dust-,chambers I I is taken out from them occasionally. y

What I claim as my invention, and desire to secure by Letters Patent of the United States, is-

1. The combination of a shaft, vertical, or nearly so, with a lire-place ator near the bottom, a flue leading from the upper part of the shaft, and an auxiliary lire-place for heating said u'e.

2. An auxiliary lire-place connected with a ilue or chamber, through which the dust passes, esff "ping-froid araSting-irnaeffoi roast;I and ehloridizejtlie ne. 'orewheh .issfear-` dust.. main furnace-chamber.

3.' A supplemental 01' auxiliary re-pla'ee, CHARLES STETEFELDT. J, combined with a furnace, B, fire-place 0,. Witnesses: dust-flue D and H', andf dust-chambers I I, MORRIS M. ESTER,-

salid auxiliary y.Ie-plaee-being arranged t0 WM.- D. HARRISON,

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