Study On The Reconstruction And Comprehensive Utilization Process Of Pyrite Concentrates

The iron content of pyrite concentrate reaches 40%and the sulfur content reaches 47%.It is an important iron and sulfur resource.At present,pyrite concentrate is mainly used for acid production.However,due to the high content of elements such as lead and zinc,higher requirements are placed on the acid production process.Moreover,the current domestic sulfuric acid market is oversupplied,making it difficult to use pyrite concentrate,which not only results in waste of resources,It will also occupy a large amount of land.Therefore,it is of great significance to carry out research on high-value comprehensive utilization of pyrite concentrates.In this paper,sulfur products and pyrrhotite pyrolysis slag are obtained by pyrolyzing the desulfurization ore phase reconstruction of pyrite in the pyrite concentrate under high temperature inert atmosphere,and the pyrolysis slag is leached by wet method or magnetic-flotation.way to make use of the valuable elements in it.The theoretical feasibility of pyrolysis of pyrite to obtain pyrrhotite and elemental sulfur was analyzed thermodynamically.Conditional test results show that the pyrrhotite pyrolysis slag and elemental sulfur products obtained under the conditions of 650℃,10 mm thickness,and heat preservation for 3 hours are better.The test results of oxygen pressure leaching conditions show that when the initial acidity is 0.8 mol/L,the leaching time is 5 h,the temperature is150℃,the oxygen pressure is 0.8 MPa,and the liquid-solid ratio is 9:1,the yield of elemental sulfur reaches 88.37%,and the content of lumps is88.37%.It is 9.71g,accounting for 99%,and the leaching rate of Fe is only 19.8%.Then,calcining the pressure-cooked slag at high temperature to obtain hematite powder conforming to the first grade of pyrite slag,the iron grade is 61.46%,and the recovery of iron element is realized.At the same time,through the"pyrolysis-oxygen pressure leaching"process,the yield of sulfur can reach 90%,and the high-value recovery of sulfur resources is realized.Process mineralogy studies show that iron,lead and zinc in the pyrolysis slag mainly exist in the form of pyrrhotite,lead sulfide and zinc sulfide inlaid with each other in fine particles.Conditional experimental results show that when the"grinding-magnetic-floating"process is used,when the fineness-0.040 mm content is 80.1%,the iron content in the iron concentrate is 57.32%,and the lead and zinc content are 0.14%and 0.10%respectively;The products of Pb and Zn are returned to the beneficiation plant for blending with the raw ore and sent to the roughing section.The SO₂ gas produced by the pyrrhotite concentrate through oxidation roasting can be used to produce high-quality sulfuric acid,and the hematite slag iron obtained at the same time.The grade is 66.26%,which is in line with the first grade of pyrite slag.The"pyrolysis-oxygen pressure leaching/magnetic-flotation"process of pyrite concentrate realizes comprehensive recovery and high-value utilization of valuable elements in it.The research content of this paper provides theoretical support for enterprises to realize industrial application.At the same time,it has certain reference significance for the efficient and high-value utilization of pyrite concentrate obtained from sulfide mines.In the dissertation,there are 54 figures,17 tables and 94 references.