Experimental Study Of 5N High-purity Quartz Processing By Vein Quartz

High purity quartz is the main raw material of quartz glass and quartz crucible.It's high-grade products are widely used in large scale integrated circuit,solar cells,optical fiber,aerospace,military and other industries.It is closely associated with the high-tech and the long-term development of the whole country.For a long time the preparation technology of high purity quartz high-end products has been monopolized by the United States,Germany and so on,and restricted exports of the technologies and product.So,how to explore a practical preparation technology of high purity quartz high-end products is a significant work.Large amounts of data show that occurrence state of the impurity in vein quartz can be divided into three categories:mineral in pore,gas liquid inclusions and isomorphism.This experiment according to the occurrence state of the impurities in vein quartz and related principles,such as sichuan region of quartz ore samples as the research object,through the acid immersion,ultrasonic assisted acid leaching,alkaline leaching,high temperature roasting,heating with microwave,Cl₂ gas chlorination roasting test,study the purification effect.Then according to the purification effect to combine different purification process,samples with different origin of quartz mine as the research object,studies the preparation of 5N feasible technology of high purity quartz.In quartz sample SY01 acid leaching,ultrasound-assisted acid leaching,alkali leaching experiment,the 5#recipe acid purification works best and purification effect of ultrasound-assisted acid leaching acid leaching alone after purification effect is roughly equal,in two bases liquid?NH₃·H₂O and NaOH?samples were alkali leaching,although the purification effect NH3·H2O than 5#acid formulation somewhat less,but when used NaOH alkaline leaching will introduce a large number of elements Na,but the two sample some lye magazine removed elements have a certain effect.The purified alkaline leaching and acid leaching effect combination of two processes separately after purification effect than the two processes,but the range is limited,with the purification effect after two processes in different orders superimposed basically the same.After the quartz samples SY01 high temperature roasting,microwave heating treatment experiments and found that under certain conditions of high temperature calcination SY01 purified sample is feasible,calcination temperature 1100?is better,the lowest total impurity content under this condition for 31.71 ug/g.Calcined at1400?,the total amount of impurity elements 34.975 ug/g,and 1100?when little difference,but the alkali metal element and an alkaline earth metal element removal effect when compared with 1100?good;after using Galanz microwave oven for home heating treatment purification the effect is not obvious,it is not feasible.Experiment with NJL2-2 microwave SY01 purified sample is feasible when the microwave power is 2KW,when the heating time of 90min total content of impurities lowest 28.34 ug/g.Chlorination roasting experiment group chlorination roasting original equipment on the basis of the experimental device has been improved,and the improved use of concentrated HCl MnO₂ reaction homemade Cl₂ chlorination roasting,making the experiment has been greatly guarantee the safety of the experiment the results showed that before the improvement and improved chlorination roasting apparatus number SY01 quartz sample purification effect equivalent;and found that the purification effect chlorination roasting 1h after the best,then the total amount of impurities is17.125 ug/g,corresponding to w?SiO₂?up to 99.99829%,the effect is not purified with the growth of roasting time and get better.According removal results for a single impurity element,a combination of a set of comprehensive optimization process for five quartz samples:SY01,SM01,YAS01,LHC01,LHC02.The comprehensive process optimization experiment found that:microwave+pickling+Cl₂+purification process acid leaching is the best process,it can be recognized as a suitable purification process for vein quartz.After these above process the w?SiO₂?of five samples is purified over reached 4N8,which the sample LHC02 is reached to 5N.