A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
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THE METALLURGY OF ANTIMONY. 83<br />
a reverberatory furnace), as used iu New Brunswick, are as<br />
follows:—<br />
Length 42' 6"<br />
Width . . . . . . . . 7' 6"<br />
Working doors on each skie . . . . , 10<br />
Height from bed to roof 2' 1"<br />
Width of fire-grate 2'1"<br />
Height of fire-bridge 5'2"<br />
Breadth of fire-bridge 1"<br />
The method of working is as follows :—<br />
Capacity of furnace . . . . . . 30 cwta.<br />
Charges . . . . . f» to o ewts. at one time.<br />
S charges (18 cwts.) during 24 hours, so that<br />
each charge remains in the furnace for 40<br />
! hours.<br />
Consumption of) m. A . -,.«,,<br />
wood j" Three-quarters of a cord m 24 hours.<br />
Loss of Sb 7*5 percent.<br />
The ore must be strongly heated, and thoroughly rabbled every five<br />
minutes during the last two hours before being drawn. Properly<br />
roasted ore must have a dull grayish-yellow colour.<br />
The furnaces, as used at Banya, have the following dimensions:—<br />
Length . . . . * 26' 3"<br />
Width 6' 6"<br />
Working doors on each side 5<br />
Ores roasted in 24 hours 24 cwts.<br />
Charges of 4 cwts. each are introduced at the colder end of the<br />
furnace, and are then finally drawn after twenty hours at the opposite<br />
end. Stepped grate is used, and the fuel is lignite.<br />
The following operation for roasting the ore is carried out in<br />
Tus % cany, Italy:—200 kilos, are charged into a reverberatory<br />
furnace, heated up a little previously. The temperature is then<br />
raised to not more than 350°. Rabbling is carried on for from three<br />
to twelve hours. Rich ores require a longer time. Each operation<br />
requires 35 kilos, of lignite, and the loss due to volatilisation is not<br />
more than from 5 to 8*5 per cent.<br />
Another type of the same kind of furnace is shown in figs. 19, 20,<br />
21, 22.<br />
Furnaces with a trough-shaped bed sloping towards one of the<br />
longer sides of the furnace have been proposed for the performance<br />
of both reduction and roasting at the same time. The use of having<br />
the slope is for the tapping off of any portion of the sulphide tliat is<br />
unavoidably liquated during the roasting.