Study On Quartzite Purification To Prepare Quartz Sand For Photovoltaic Glass

Quartz is an important raw material for the development of many industries in the country,especially for glass manufacturing.The raw material required for quartz sand accounts for more than 70%of all materials,and the demand is very large.In recent years,after China goverment put forward the concept of"carbon peak carbon neutralization",the country has paid more and more attention to clean energy.Photovoltaic power generation has also been greatly sought after as one of the most important clean energy sources.Due to the limited output of high-quality photovoltaic quartz sand,the photovoltaic glass market is currently in a state of short supply.Therefore,it is of great significance to use quartzite ore with large deposits and large ore reserves as the raw material for preparing quartz sand for photovoltaic glass.The mineral composition of ore is complex,with different particle sizes and varying degrees of variation.It is necessary to explore the beneficiation process and process according to the properties of different ores.This paper took a quartzite mine（GS）in Gansu as the main research object,and compared two quartzite mines（YC-1,YC-2）in Yichang,on the process mineralogy of the ore,the effects of grinding media,and the effects of grinding particle size.Magnetic separation process,scrubbing process,flotation process,acid leaching process,acid leaching kinetics,etc.were studied,and the industrial beneficiation process route with strong versatility,green environmental protection,high efficiency and convenience was selected,which can purify the beneficiation of the entire quartzite ore.The main conclusions of the paper are as follows:1.Both GS raw ore samples and YC raw ore samples were abundant in Si O₂content,and the main impurity elements were Al,Fe,Mg,Ca,Ti,K,Na,and Mn.The main gangue minerals that occur between the particles of quartz were sericite（muscovite）,rutile,hematite,tourmaline,epidote,zircon,amphibole,etc.It was fine and had a certain amount of fine-grained quartz aggregates.2.High-alumina ball milling caused less pollution to the ore sample than steel ball milling,but the grinding efficiency was poor.In the magnetic separation-acid leaching process,most of the mechanical iron contamination caused by the steel ball milling to the ore samples could be treated,so the steel ball milling had little effect on the iron content in the final concentrate.Controlling the grinding particle size was beneficial to reduce the Fe₂O₃ content in the final concentrate,but the same process can also achieved the standard of quartz sand for photovoltaic glass without reducing the maximum particle size.From the perspective of reducing beneficiation costs,-0.6mm+0.1mm particle size was more suitable for processing and purification.3.Increasing the number of magnetic separation stages and increasing the strength of the magnetic field was beneficial to iron removal from quartzite ore,but this may increased the cost of beneficiation.Therefore,the three-stage magnetic separation was a more suitable choice,and the magnetic field strength of 1.4T was also a more suitable choice.The Fe₂O₃ content of the final concentrate product of the GS sample magnetic separation was 422.23μg/g.The scrubbing experiment showed that the scrubbing effects was best under acidic conditions,but it was mainly due to the chemical reaction between the acid and the iron film,and had nothing to do with the scrubbing experiment.The flotation test showed that the best condition was to use SD-2#petroleum sulfonate sodium reverse flotation quartz under acidic conditions,and the Fe₂O₃ content of the final concentrate product of GS sample flotation was 184.91μg/g.4.The Fe₂O₃ content in the concentrate sample of the GS sample was 118.95μg/g after a magnetic separation-acid leaching purification process.By comparing the magnetic separation-acid leaching process and the magnetic separation-flotation-acid leaching process,it can be seen that the flotation effects was poor,and the magnetic separation-acid leaching process was more suitable.According to the study of acid leaching kinetics,the acid leaching of GS sample conformed to the chemical reaction mixed control model（1-α）^-1/3-1+1/3 ln（1-α）=k t.The apparent activation energy E of the chemical reaction was 10.4k J/mol,and the kinetic equation of leaching was（1-α）^-1/3-1+1/3ln（1-α）=4.82×10^-2e^{-2.44×10-3/RT}t.The research on the acid leaching process showed that the optimal acid leaching temperature was 85℃,and the optimal acid leaching mixed acid ratio was 1%HF+10%oxalic acid.5.According to the study of process mineralogy,the particle size and impurity content of the three kinds of quartzite ores were obviously different.The process of iron ball grinding-magnetic separation（1.4T,3 stages）-acid leaching（85℃,1%HF+10%oxalic acid）could make the three kinds of quartzite ores meet the standard of quartz sand for photovoltaic glass.The Fe₂O₃ content in the final concentrate products were:GS sample was 58.62μg/g;YC-1 sample was 79.46μg/g;YC-2 sample was 74.79μg/g.