Experimental Study On Recovery Of Ultra-fine Pyrite In Fankou Lead-zinc Mine

Recovery of the ultra-fine pyrite from the tailing with an average particle size of10μm in Fankou Lead-Zinc Mine was studied in this dissertation. Plant survey showsthat the overflow of1#thickener, which was directly sent to the section for preparationof backfilling tailing after concentrating by Ф53m thickener, accounted for13%~20%of the lead-zinc tailing. Batch floatation tests for recovering the ultra-fine pyrite fromthe underflow of Ф53m thickener were carried out. It is demonstrated that the bestrecovery process of ultra-fine pyrite is that after desliming to the underflow of Ф53mthickener by hydrocyclone, the hydrocyclone underflow is mixed with the feed of pyriterecovery circuit and experiences the original pyrite circuit. The new process can notonly increase the maximum of pyrite recovery, but also reduce the amount of oredelivered to the tailings dam.Processing mineralogy showes that the main elements which can be beneficiatedby mineral processing are iron and sulfur. The grades are23.21%and25.04%respectively. Metallic minerals are mainly pyrite, occasionally sphalerite and galena.Gangue minerals are mainly quartz, calcite and sericite. The completely liberated pyriteaccounts for94.93%.Flotation tests show that the sulfur grade and recovery of concentrate were47.05%and84.36%respectively, when the underflow of Ф53m thickener directly go throughthe closed floatation circuit. However, after desliming by hydrocyclone, the sulfur gradeand recovery of rougher flotation concentrate to the hydrocyclone underflow were44.45%and57.67%respectively. Mixed the hydrocyclone underflow with the feed of pyritecircuit at the dry weight ratio of2:8, the grade and recovery of rougher concentrate was43.25%and58.15%respectively, which were similar to the index of rougherconcentrate in pyrite circuit. From all above, mixed flotation process was feasible inindustrial production.The industrial test results show that compared with the index of sulfur concentrateof the original pyrite circuit, the sulfur recovery of mixed flotation technology increases 5.22%at the sulfur grade of above47%. Take no account of the processing cost, newtechnology produce more67300tons of high qualified concentrate and sale revenueincrease9.237million yuan every year. The new process has the characteristics of lessinvestment and fast effect.