A major development in British extraction metallurgy—a process for smelting lead-zinc concentrates in a blast furnace to yield both zinc and lead as metals directly—has been brought to commercial success by the Imperial Smelting Corporation Ltd. Two furnaces are now in operation at Avonmouth, producing between them 70 tons of zinc per day and varying quantities of lead, depending on the nature of the charge.

Instrumentation and automatic control are features of the process, and a battery of platinum : rhodium-platinum thermocouples is installed for the measurement of temperatures in the higher ranges.