The leading reverberatory furnace for roasting lead-bearing sulphide ores has a level hearth 14-16 ft.
Carmen carried the basket of eggs to the counter beside the sink and watched as Alex took the lid off the roasting pan.
It is obtained commercially by roasting arsenical pyrites in either a Brunton's or Oxland's rotatory calciner, the crude product being collected in suitable condensing chambers, and afterwards refined by resublimation, usually in reverberatory furnaces, the foreign matter being deposited in a long flue leading to the condensing chambers.
An impure form of the salt is prepared by roasting blende at a low temperature.
Stall and heap roasting require considerable time, and can only be economically employed when the loss of the sulphur is of no consequence; they also occupy much space, but they have the advantage of requiring little fuel and handling.
This operation is both more costly and more delicate than the roasting of pyrites, but it is now perfectly well understood, and gas is obtained from blende furnaces hardly inferior in quality to that yielded by pyrites kilns.
After the twenty-eighth of October when the frosts began, the flight of the French assumed a still more tragic character, with men freezing, or roasting themselves to death at the campfires, while carriages with people dressed in furs continued to drive past, carrying away the property that had been stolen by the Emperor, kings, and dukes; but the process of the flight and disintegration of the French army went on essentially as before.
In the roasting process, sulphuric acid is formed and acts on the clay to form aluminium sulphate, a similar condition of affairs being produced during weathering.
The dried dung of the llama (taquia) is generally used as fuel, as in pre-Spanish times, for roasting ores, as also a species of grass called ichu (Stipa incana), and a singular woody fungus, called yareta (Azorella umbellifera), found growing on the rocks at elevations exceeding 12,000 ft.
Two oxides of germanium are known, the dioxide, GeO2, being obtained by roasting the sulphide and treatment with nitric acid.