To comprehensively utilize the iron in sulfuric acid slag,the flotation-roasting process is studied by experiment to purify the raw materials of sulfuric acid slag,sulfur concentrates,and remove the impurities,and investigates the influence of the grinding fineness,the inhibitor and the collector on the test index.The results show that when the grinding fineness -0.074 mm accounts for 70 %,the sulfur concentrate grade is improved by adding an efficient inhibitor to inhibit gangue minerals to flotation and using butyl xanthate as the collector;the concentrate obtained in the closed-circuit flotation test is further roasted,which,under the proper control of roasting conditions,obtains the sulfuric acid slag with an iron grade over 65 % and sulfur content below 0.4 %,and can be sold directly as iron concentrate.The process can comprehensively recover iron,fully utilizing the resources of sulfuric acid slag and creating significant profits for enterprises.