广东某高岭土尾砂工艺矿物学研究及其高纯石英砂提纯潜力评估OA

High-purity quartz sand is an indispensable key raw material for semiconductor,photovoltaic and high-end optical industries.In order to realize the resource utilization of solid waste,a sedimentary rock weathering residual kaolin tailings in Guangdong was used as raw material,and its process mineralogy characteristics were systematically characterized by analysis means of X-ray diffraction,X-ray fluorescence spectroscopy,stereomicroscope and transmis-sion polarizing microscope.The purification potential was evaluated by the combined process of'scrubbing-magnetic separation-flotation-acid leaching-calcination-secondary acid leaching'.The results show that the+0.25 mm fraction sample in the raw ore has the characteristics of high silica content and low gangue mineral content,which can be used as the preferred raw material for the preparation of high purity quartz.After the combined process,the purity of silica in the obtained quartz concentrate is 99.98％(3N8),and the total impurity mass fraction is reduced to 187.03 μg/g.The mass fractions of aluminum and iron are 94.79 μg/g and 8.50 μg/g,respectively,which meet the requirements of JC/T 2314-2015"Silicon raw materials for photovoltaic glass".However,the micron-sized solid inclusions remaining inside the quartz particles are the main factors restricting the further improvement of its purity to 4N5 level.The kaolin tailings have good potential for preparing high-purity quartz sand,but to obtain higher purity products,it is still necessary to further develop a targeted deep removal process for solid inclusions.