Two furnaces are always placed
side by side, and the pair have from 1,100 to 1,150 aludels.
The operation is as follows: A layer of poor quartz is spread over the
brick grate; this is followed by a layer of smalls, and then by a
layer of still finer stuff, all of it being low grade ore. On top of
this are piled two-thirds of the _china_ of the charge on which the
_metal_ is put. Then follows a layer of _requiebro_, another lot of
_china_, and finally the _vaciscos_, shaped into balls, the whole
charge amounting to about 111/2 tons, which is put in from an hour and a
half to two hours by three men. The charging orifice is then closed,
the aludels are luted, and everything made tight. The fires under the
brick grate are lighted and kept going for twelve hours, during which
time furnaces, charge, and condensing apparatus are heated up. During
this period, the temperature in the condensing-chamber at the end of
the line of aludels runs up 40 or 50 degrees Celsius, and some
mercury, evidently part of the native quicksilver, is noticed in it.
The temperature of the aludels in the immediate vicinity of the
furnaces is about 140 degrees C. During this period, the consumption
of fuel is four parts to every part of quicksilver produced. At its
close, the fire is drawn, and the second period begins.
Pages:
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128