Study On Beneficiation Process Of Pyrite In South Of Sichuan And Comprehensive Utilization Of Residue

Pyrite is an important industrial chemicals. China’s pyrite reserve is at the forefrontof the world. But in recent years, with the rapid development of our economy, and theincreasing demand of the market of pyrite, the mineral resources shows a poor, thin,miscellaneous trend. The situation of improving pyrite’s grade, comprehensive recoveryand utilization of the tailings is becoming increasingly serious. Now, due to thebehindhand economy, mining technology and technical and other reasons, manymineral processing plants are using single gravity method, or simple flotation, the pyriteconcentrate’s grade and recovery are low. And the tailings are discarded or dischargedinto the rivers, not only caused the waste of resources and also seriously polluted theenvironment. So studying new flotation reagents and developing new beneficiationprocesses,improving the pyrite’s gradeand recovery, carrying out the key technologieson resources and full quantization use of kaolin residue, are not only protect ourenvironment but also creat enormous economic benefits. That is an effective way ofsustainable development.The pyrite mine studied in this paper is from Sichuan. Firstly, The basic propertiesof pyrite were studied by various analytic methods. And the flotation reagents, flotationprocesses conditions were explored and discussed minutely and seperately. On thisbasis, the Kaolin’s composition and basic properties were analsised, the conditions andprocesses of desulfurization and removal of iron were studied, also resources utilizationwas researched. Conclusions are as follows:This pyrite is yellow-brown,with green-black or brown streaks, has a strongmetallic luster, its density is5.50g/cm3, hardness, low grade. It is mainly composed withpolycrystalline agglomerate structure and tuberculosis-like structure, and a littlemildew structure, basically showed grainy structure. The primary crystal are ferrousSulfide （FeS₂） and kaolin, their crystal morphology are good. The main gangue mineralis kaolinite, has a percentage of95%, a small amount of pearl clay, calcite, siderite,and the rest are dickite, organic matter and so on. The Kaolin in tailing is easy to behydrate, it is composed with Al₂O₃and SiO₂crystals. its main coloring impurity areFeS₂and TiO₂. The proportion of pyrite and kaolinite is great than1.5, so this ores areeasy to be chosed. With the floatation process of pyrite concentrate, the new flotation reagentformulations, beneficiation process and conditions were explored. Experiments showed:under neutral conditions, the ethyl xanthate and butyl xanthate as mixed collectors（mass ratio was1:1）, the consumption was266.7g/t; CuSO₄as activator, the amountof300g/t; tannic acid as kaolin’s inhibitor, the amount of166.7g/t; terpineol was1000g/t, pulp density was33%, flotated15min, the pyrite concentrate’s grade was51.2%, the recovery rate was86.1%. The pyrite and kaolin were successfully efficientseperated, and the costs was brought down, also the environmental pollution wasreduced.Compared the anti-flotation method and the electric field with the process ofdesulfurization and removal of iron of Kaolin. It was proved that: using anti-flotation,and this flotation reagent formula: Na₂CO₃0.09g/L+Na₂SiO₃0.11g/L+butylxanthate0.08g/L+terpineol0.10mL/L, and pulp density was15%, flotated10min, theiron content in the Kaolin could be decreased from6.05%to1.04%, sulfur contentcould be decreased from5.64%to0.69%, kaolin recovery rate was up to71.4%,achieved the impurity index. An fast, simple and efficient beneficiation process wasdeveloped.The basic properties of kaolin residue were studied by various analytic methodswithin the resource utilization process Kaolin. It found that this residue was mainlycomposed of SiO₂, Al₂O₃, and the content of Si, Al, Ti was higher, both of them wereuseful component to the denitrification catalyst, and effectively improved the activityof the catalyst. The content of P, K which was toxic to catalyst was very low. Thefeasibility of this residue as the vanadium denitration catalyst carrier was studied, alsothe effect of active components and different additives on its catalytic activity wasresearched. The results showed that the kaolin slag carrier had the same performance asthe commercial catalyst carrier TiO₂. The catalyst ‘s bonding properties and moldingwere in good condition. Experiments proved the activity of catalyst of2%V₂O₅-8%*WO₃-KS could up to88.7%, the activity of the rare earth oxide catalyst of2%V₂O₅-8%CeO₂-KS was80.0%. Not only a new areas on the utilization of kaolin wasopened up, but also the cost of commercial catalyst was reduced, and the environmentalproblems were effectively solved.