Converting of copper-lead matte: loss of gold and silver with slag

Abstract

Based on comprehensive studies, including methods of elemental, X-ray phase analysis and mineralogical studies of solid slag and dust samples, quantitative ratios of the forms of finding copper, lead and precious metals are determined, a mechanism for the distribution of gold and silver between converting products is established. It is shown that the loss of gold and silver under the conditions of converting of copper-lead matte is associated with their redistribution between converter slag and dust. It was established that the loss of gold with converter slag and dust is determined by the content of mechanical losses of copper in them. Loss of silver in the slag is determined by the content of lead in them. As a result of mathematical processing of the compositions of the converting products, the regression equation of pair correlation is constructed, which describes the dependence of the gold loss in slag on the mechanical loss of copper in it with a high correlation coefficient (r = 0.92). An increase in mechanical losses of copper in slag from 0.5 to 0.95% leads to an increase in the gold content in slag by more than 1.5 times. An increase in the copper content in the form of sulfide in dust from 1.5 to 3% increases the gold content in dust from 2 to 7%. Unlike gold, silver is highly correlated with lead. An increase in the content of lead in slag from 17 to 25% increases the silver content in it from 100 to 150 g / t. It is shown that in the process of converting copper-lead matte, it is necessary to provide measures to minimize losses of copper and lead in slag, which will reduce the gold and silver contents in them and significantly increase their extraction into blister copper. To reduce the loss of gold, a solution is necessary on the one hand, the task of reducing the mechanical loss of copper with slag, and on the other, minimizing dust removal under conditions of converting copper-lead mattes.