Arsenic removal from blister copper by soda injection into melts

Abstract

Soda injection into a blister is one of the most important operations in the copper refining processing. The aim of this work is to determine optimal parameters of a technology for arsenic removal from anode copper by use of soda (Na2CO3) injected into a molten copper bath by submerged tuyeres. Results of the work reveal that the rate of reaction between soda and arsenic is very high and sodium arsenate Na3AsO4 is formed. These findings have been used to work out a table, which gives the amount of soda to be used in the process as a function of refined copper quantity and arsenic content. The second part of this work is to demonstrate the use of nitrogen as a carrier gas for soda injected into the blister for arsenic removal. An application of neutral gases in this process is beneficial, and results in energy conservation.