Study On Highly Efficient Flotation Recovery Of Element Sulfur From Zinc Smelting High-Sulfur Slag

In view of the characteristics of the high-sulfur slag from the second-stage oxygen pressure acid leaching of zinc,the particle size is small,the mineral phase is wrapped and embedded,and it is difficult to effectively recover.This paper focuses on the key scientific issues of efficient separation of elemental sulfur from other mineral phases in high-sulfur slag,DTF simulation calculation of the adsorption performance of ethyl sulfide and nitrogen,the influence mechanism of ethyl sulfide and nitrogen in single mineral flotation process,and the research on high-efficiency flotation process of high-sulfur slag are carried out.It provides a theoretical basis for the efficient recovery of elemental sulfur.The main findings of this paper are as follows:（1）The DTF simulation calculation of the adsorption performance of ethyl sulfide nitrogen shows that:the sulfur atom and nitrogen atom in the ethyl sulfide nitrogen molecule are the active potential for surface adsorption.The effect of ethyl sulfide on the surface of sulfur is dominated by dispersion force,and the adsorption energy is-4.18 kJ/mol;The role of ethyl sulfide nitrogen on the surfaces of sphalerite,pyrite and lead sulfate is dominated by metal bonds and ionic bonds.TheS atoms in the ethyl sulfide molecule interact with the metal atoms on the mineral surface to form metal bonds or ionic bonds,and the adsorption energies are-42.568 kJ/mol,-195.64 kJ/mol,and-81.05 kJ/mol,respectively.（2）Study on the influence mechanism of ethyl sulfide and nitrogen in single mineral flotation process shows that:sulfur itself has good floatability and is less affected by the concentration of ethyl sulfide nitrogen.The recoveries of pyrite,sphalerite and lead sulfate all increased first and then remained unchanged with the increase of the concentration of ethyl sulfide nitrogen.Through infrared spectrum analysis,the chemisorption of ethyl sulfide nitrogen occurred on the surface of pyrite,lead sulfate and sphalerite,but no chemisorption occurred on the surface of sulfur.（3）High-sulfur slag high-efficiency flotation experiments show that the optimal flotation process conditions are:flotation time 15 min,pulp temperature 25℃,pulp concentration 15%,air flow 300 L/h,pulp pH value 8,ethyl sulfide nitrogen dosage 300 g/t,50 g/t terpineol oil,500 g/t Na₂SiO₃,ZnSO₄ and CuSO₄ concentration 500 g/t.Under these conditions,the recovery rate of elemental sulfur reaches 98.37%,the grade of sulfur concentrate reaches 72.26%,and the sulfur content of tailings is 4.58%.Most of theS in the high-sulfur slag and a small part of Fe and Zn are enriched in the concentrate in the form of S₈,FeS₂,ZnS,and most of the Fe,Zn,S,Pb,Ag,Ca,Si are in the form of FeS_2,ZnS.PbSO₄,SiO₂,CaSO₄ in the form of enrichment in the tailings.High-efficiency separation of elemental sulfur and other mineral phases is achieved.50 figures,12 tables,and 73 references.