Improving the quality of cathode copper at the Copper Plant by partially replacing thiourea with Poly Mud FL1 hydrolyzed polyacrylonitrile (HPAN)

To improve the quality of cathode deposits and the technical and economic performance of the copper electrolytic refining process, surfactants are used in the Copper Electrolysis Shop of the Copper Plant of the Polar Division of PJSC MMC Norilsk Nickel (hereinafter referred to as the CES CP PB). The colloidal mode in the CES CP involves introducing a complex of surfactants into the copper electrolyte: hide glue and thiourea (hereinafter referred to as TU). At the same time, under conditions of intensive electrolysis, the decomposition products of TU are included in the cathode metal, which leads to an increase in the sulfur content in copper cathodes. According to GOST 859–2014, the sulfur content in M00k cathode copper should not exceed 15 g/t. Moreover, consumers are tightening requirements for cathode copper, and in order to meet the requirements of the target market, the sulfur content in this product should not exceed 8 g/t. One of the ways to achieve this goal is to replace TU with a colloidal additive of similar action that does not contain sulfur. The conducted review of technologies at modern copper refining plants showed that some of them use hydrolyzed polyacrylonitrile (hereinafter referred to as HPAN) as an alternative to TU. To determine the feasibility of partial or complete replacement of TU with the specified reagent, laboratory and pilot tests of Polly Mud FL 1 HPAN were consistently carried out. The article presents the results of laboratory and pilot tests on partial replacement of TU with HPAN in the process of copper anodes electrorefining at the CES CP PB.