METALLURGICAL REQUIREMENTS FOR REFRACTORIES IN THE ELECTROTHERMIC METALLURGY OF ZINC1

Refractory brick for lining electrothermic dry distillation furnaces must have a melting point of not less than 1600°C, must retain their strength at temperatures of 1400–1500°C, must be non-porous, and of uniform size. For lining electrothermic smelting furnaces, in which a liquid slag is produced, they must in addition to having these qualities be resistant to the corrosive action of highly heated slags which may be either strongly acid or strongly basic. The condensers are similar for both types of furnace. The brick for lining them need not have a high melting point but must be dense and of uniform size and must be very low in free iron oxide to withstand the disintegrating effect of carbon monoxide in the cooler portion of the condenser.