Study Of The Synthesis Of4A Zeolite Using Pyrite Tailings In Southern Sichuan

Throughout southern of Sichuan, bears very rich pyrite resources. In the longprocess of pyrite mining and beneficiation, there has accumulated a large number oftailings, and the accumulations of the tailings has reached more than10million tonsin these decades. Since no effective utilization method, such a huge quantity oftailings has not been a good development and utilization. The accumulation of tailingshas caused serious harms of Ecological environment, industry and agricultureproduction and people’s health. It has caused serious environmental pollution andaroused great attention of local government departments. Therefore, how to improvethe comprehensive development and utilization of pyrite tailings is closely relatedbetween the economical and sustainable development in the region.Kaolin as the the main mineral composition in the tailings is one of the rawmineral materials to obtain4A zeolite. Iron and titanium mineral impurities in thetailings has affected the performance of kaolin, and make it particularly complex touse the pyrite tailings to obtain4A zeolite. Although the preparation of4A zeolite hasbeen relatively mature, there is no try to obtain4A zeolite using tailings especiallyusing Pyrite tailing. The innovation of this paper is taking pyrite tailings as rawmaterial to the preparation of4A zeolite to get a suitable synthetic process. It hasprovided a cheap natural mineral to obtain4A zeolite, at the same time as the basis ofpyrite tailings using provides a feasible way. In this paper we have studied theproducts of different processes and get the optimize parameters to synthesize4Azeolite by pyrite tailings using X-ray fluorescence(XRF), X-ray diffraction (XRD),whiteness meter, laser particle size analyzer, scanning electron microscope(SEM) andcalcium ion adsorption experiment.(1) The molar ratio of SiO2and Al2O3in the pyrite tailings is extremely satisfiedthe preparation conditions of4A zeolite. The major mineral composition of the pyritetailings is flake crystal kaolinite, which contain amounts of pyrite, hematite, anabases and other impurities, with an uneven distribution of the particles particle size of1~5μm.(2) Since the high content of impurities in pyrite tailing, the ingredients of pyritetailings need to be adjusted for the synthesis of4A zeolite. Firstly, the pyrite tailingsare dealt with floating, and then floating tailings are washed by mixed acid withdifferent concentrations of HCl+H2SO4. By these, the whiteness and calcium ionadsorption performance of4A zeolite could be improved, and the optimum processconditions were determined: the concentration of mixed acid is30%HCl+30%H2SO4.(3) By adopting single-factor experiment during the hydrothermal synthesisprocess, the optimum process conditions were determined: sintering temperature is630°C, sintering time is3h, alkalization temperature is50°C, alkalization time is3h,crystallization temperature is92°C and crystallization time is3h.(4)The analyses of XRD patterns revealed that both the phases of4A zeolite ispure, with other mineral impurities almost no exist. The analyses of SEM photosconfirmed that the4A zeolite is in cube crystal shape with intact growth and thedistribution of crystal grains is1~2μm.(5)The synthesis of4A zeolite was analyzed by using the white tester and the laserparticle size analyzer and the calcium ion adsorption experiments. The results showthat whiteness, the average particle size and the particle size(less than4μm) of4Azeolite synthesis by pyrite tailings were86.45%,2.11μm and84.51%~89.84%,respectively.