Hydro - pyrometallurgical treatment of copper converter flue dust
No Thumbnail Available
Date
2017-01-01
External link to pdf file
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85014130064&origin=inward
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The aim of this study is to investigate the possibility of pyrometallurgical recovery of lead and bismuth from preliminary desulfated copper converter flue dust into a metal phase, by carbothermal reduction in a soda ash smelt. Hydrometallurgical treatment of flue dust is actually caustic leaching and it aims to remove the sulfate sulfur. The desulfation degree of the converter flue dust, using 35 g NaOH per 100 g dust, is 80 % and the total impurities concentration in the Na2SO4 solution is below 50 mg l-1. The solid product from the hydrometallurgical step was subjected to pyrometallurgical treatment in a soda ash smelt. The effect of temperature, reducing agent type and amount, soda type and amount, on metal yield as well as the distribution of Pb, Bi, Cd, Ag and Cu among the process products, have been determined. It was found that with the increase of temperature, reducer and soda amounts the metal yield increased, but the copper and silver concentrations in the metal phase also increased. The laboratory experiments showed that it is possible to recover Pb and Bi a in separate product at a temperature of 900oC. The optimum established parameters for carbothermal reduction of desulfated copper converter flue dust are: temperature 900°C, soda amount 50 % of the dust mass, reducer amount 10 % of the dust mass and process duration 30 min. The recovery rates of lead and bismuth at these conditions are 80 % and 65 %, respectively. The obtained alloy consists of 74.87 % Pb, 12.96 % Bi, 0,22 % Cd and 11.63 % Cu. Semi industrial experiments should be carried out to clarify the optimal process parameters, since the furnace type and the method of charge heating will also influence the distribution of the metals among the products of smelting.