Study On The Flotation Of Tin-bearing Multi-metal Sulfide Ore With High Sulfur By Two-step Pulp Potential Regulation

Cassiterite-sulfide-type primary ore is an important tin-bearing resources,whose high-efficiency separation and recovering will be beneficial to alleviate the domestic current shortage of tin resources.For this reason,a systematic study on the beneficiability of cassiterite-polymetallic sulfide ore with high sulfur has been conducted,and the two-step pulp potential regulation mechanism for selective flotation of sulfide ore is revealed.The conclusions in this thesis can be drawn as follows:(1)Based on the research on process mineralogy,it’s confirmed that selective flotation is an optimal approach to remove and selectively recover metal sulfide minerals from ore,and the closed-circuit results of Zn-S selective flotation show that under the action of two-step pulp potential regulation mechanism,the Zn grade of zinc concentrate is 44.81%with94.49%Zn recovery,and zinc concentrate contains 2.05%copper with81.15%recovery.The S grade of sulfur concentrate is 44.12%with 73.75%S recovery,and the final closed-circuit tailings of sulfide flotation contains16.09%sulfur and 4.92%tin with 10.08%S recovery and tin recovery.(2)The results of cassiterite gravity separation show that classification-gravity separation is suitable for the recovery of cassiterite from closed-circuit flotation tailings of sulfide minerals,and the cassiterite concentrate grading 25.60%Sn,55.22%Sn and 71.86%Sn can be obtained from+74μm,-74+37μm and-37μm particles with 89.50%,96.08%and46.41%operation recovery of tin,respectively.(3)Research shows that it can guarantee a good separation of marmatite from pyrite and pyrrhotite when air agitation is carried out by opening and adjusting the charge valve of self-aerated flotation to control the pulp potential in the stage of sulfur depression by lime and subsequent copper-activation.The in-situ analysis on pulp by Raman spectra indicate that under the action of lime,the resultants like calcium polysulfide CaS_n(n=2-8)will be generated in the flotation pulp,and polysulfide can react with added copper sulfate quickly,forming brown precipitates,which will make copper sulfate lose ability to activate the zinc flotation.Two-step pulp potential regulation will creat a favourable pulp environment for copper activation of zinc.