426
P. R. Taylor
TEMPERATURE
CONTROLLER
TEMPERATURE
RECORDER
MASS FLOW-METER
THERMOCOUPLE
STAINLESS STEEL
REACTOR TUBE
CRUCIBLE
FURNACE
FIRECLAY
CRUCIBLE
THERMOCOUPLE
N 2
O 2
OR
AIR
ICE
CONDENSER
SO 2 ABSORPTION
TO EXHAUST
Fig. 10 Tube furnace schematic
0
10
20
30
40
50
60
70
80
90
100
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
Lead Recovery, %
Na 2 CO 3 /PbS Ratio
860 o C, 25% NaCl, 2 Hrs.
Fig. 11 Effect of soda ash to lead sulfide ratio on lead recovery