IE33648L - Zinc-lead blast furnace - Google Patents

Abstract

1,234,451. Extracting metals. IMPERIAL SMELTING CORP (N. S. C. ) Ltd. May 28, 1969 [June 12, 1968], No.27888/68. Heading C7D. In a method of operating a zinc-lead blast furnace into which are charged carbonaceous fuel and a sinter containing zinc oxide and lead oxide, pre-heated oxygen-containing gas being blown in through tuyeres near the bottom of the furnace, while below these tuyeres molten lead and slag are run off, the zinc oxide in the charge being reduced to zinc vapour which is taken off and condensed, the ratio of zinc to carbon in the charge and the pre-heat temperature of the blast are adjusted in accordance with the continually monitored values of (1) the said zinc/carbon ratio (2) the said pre-heat temperature (3) the ratio of slag-forming materials to carbon in the charge (4) the composition of the product gases from the furnace (5) the zinc content of the slag (6) the temperature of the molten slag leaving the furnace, so as to maximize the zinc elimination according to the relationship: - in which R z = zinc elimination V = a constant S z = weight of slag-forming material in charge/ weight of zinc in charge F = 1/D = 1/zinc-carbon ratio in charge K<SP>1</SP> = a constant p+1 = moles of carbon burnt per atom of oxygen in the blast T p = pre-heat temperature of blast b 0 to b 5 # = polynomial co-efficients a 0 to a 5 # [GB1234451A]