The Impact of the Imperial Smelting Furnace on Non-ferrous Metallurgy

Abstract

IN 1936 at the Avonmouth Works of the National Smelting Company in England, zinc was produced by both the Hori-zontal Process and by the Vertical Retort Process, then recently installed under licence from the New Jersey Zinc Company. In the Research Department we were not satisfied with either process. The Horizontal Process was inter-mittent in operation, and was a heavy consumer of fuel. In addition, the vast number of small retorts which were used, required a considerable amount of labour, and the work was hot and arduous. The Vertical Retort Process represented a considerable improvement, in that it was continuous in operation, and the consi-derably fewer retorts required much less labour and the thermal efficiency was higher. It was still essen-tially a small unit operation however, maintenance costs were high, and to make good briquettes, a coal of special quality was required, which was in limited supply.