Arsenic content in the lead flotation concentrate in dependence on NaCN dosage

Abstract

Flotation properties of arsenopyrite are similar to the flotation properties of pyrite. Specifically, in the alkaline conditions (pH value of pulp 7-11) and in the presence of xanthates as collectors, arsenopyrite can easily pass into concentrate. Therefore, if the ore contains arsenopyrite as supporting component, its flotation characteristics can affect the certain difficulties in the flotation of other minerals (Pb, Zn, Sb, W, etc.), because arsenic is considered as harmful element in almost all concentrates of metallic minerals. To the aim of obtaining high quality flotation concentrate, it is often necessary to depress arsenopyrite, which can be successfully achieved by applying of cyanides. This paper presents the results of laboratory tests, performed in order to determine the possibility of obtaining a lead concentrate with low content of arsenic. Ore sample, which was used in this flotation testing, contained a large amount of arsenopyrite (over 40% by mass). The results showed that arsenic content in the rough lead concentrate can be decreased up to ten times compared to its content in the ore, using NaCN as depressant.

Keywords

• arsenic
• sodium cyanide
• flotation concentrate