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AND OTHER METALS FROM PYRITES. 107 
or in a cases the ore may be subjected to a pre- 
liminary smelting. The method of getting rid of the quartz must 
depend i on the price of labour, fuel, &c., and the compo- 
sition of the ore. I have found, on the one ‘hand, t that re all 
req ac t the p 
absence a copper ; 2nd, the proportion ope pei and 3rd, the 
presence or absence of: lea d. 
To begin with the simplest case, viz., with pyrites free fro 
copper. The apparatus required consists of—1l, a roaster, ms 
ar pyri 
2, a reverbatory fu ,F; 3, senic flue,B (if the tes 
nical) ; 4, a leaden combination ,c; 5, a 
condensing tower, D; 6, a series of lixiviating tanks rs 
t is best to constru e f oaster, arsenic flue, convert- 
ing chamber, and tower in one line, so that the waste heat from 
the reverberatory furnace heats the sole of the Se tesees§ and con- 
verting ¢ er. The reverberatory furnace is constructed in 
the usual manner, but the sole is made simply of brick, and fiat, 
with an opening in the centre or side, f, through which the charge 
may be raked out into an iron hopper waggon, G. ie roaster, 
A,is built as a muffle, with a sole of brick, or cast-iron plies laid 
at a slight incline, to facilitate the transference of the charges. 
At the lower end there is a depression of about six inches, forming 
a , E, which extends half-way er the rever ory furnace 
and has ‘an opening, which can be ¢ with a slide, through 
which the contents of the recess may he at once Saas tee to 
the furnace. At the end of the roaster is an arsenic flue if 
required. Farther on is the combination chamber, built of sheet 
pebbles. ported on iron bars a 
space for cis entry of the gases evolved in the roaster. Sur- 
