The use of inhibitors to prevent scale formation in sulfur floatation process equipment at Nadezhda Metallurgical Plant

Abstract

The paper describes possible reasons and solutions to reduce the rate of salt deposits in process equipment of the elemental sulphur production shop at Nadezhda Metallurgical Plant named after B. I. Kolesnikov of the Polar Division of PJSC MMC Norilsk Nickel. Key scale components are elemental sulphur, calcium, ferrum, presence of gypsum, hematite, chalcopyrite and pyrrhotite. The reason for a higher scale formation in winter is a temperature difference of sludge along the floatation line, resulting in reduced solubility of calcium compounds in a liquid phase and their settlement as deposits on equipment walls. When seeking for a solution to reduce the stated process, laboratory studies were carried out to simulate the sulfur flotation process under conditions of an artificial decrease in sludge temperature with the addition of a scale inhibitor and magnetic treatment of sludge. It was found that a sharp drop in sludge temperature during aeration contributed to a more intensive transition of calcium ions from the liquid phase to the solid one compared to the control experiment, evidencing a higher probability of gypsum precipitation on equipment walls. Adding scale inhibitor MK-1 with a specific flow rate of 50 g/t resulted in a reduced transition of calcium ions from the liquid phase to the solid one by 18.3%. The degree of deposit weight reduction on the test samples compared to the basic experience was 91.5%. When applying magnetic treatment of sludge, the degree of deposit weight reduction on the test samples was 75.6%.The following specialists of the Polar Division of PJSC MMC Norilsk Nickel have contributed to the research: V. S. Grebennikov, I. A. Dolganev, D. V. Sergienko, Yu. A. Nikolaeva and others.