Study On The Process Conditions Of Activated Zinc Oxide By Ammonia Complex Leaching Technique

Activated zinc oxide is a significant inorganic chemical material ,which is mainly applied in the industrial fields of rubber, pigment, chemical, china, medicine, glass, fertilizer, electricity and so on.With the development of national industry in China,more and more activated zinc oxide is needed.thus,many people pay great attention to the preparation of itPresently the study of zinc oxide attended to activated and nano zinc oxide in and out abroad.There are two main basical preparation methods of activated zinc oxide.one is acid leaching method;the other is ammonia complex method. To the former,it's process is complex,it's cost is expensive, whatmore it's waste is difficult to deal with.while the latter,it's process is simple,and it's cost is rather low.In term of resource which is zinc oxide fume dust with zinc sulphide from some zinc oxide factory,the fundamental research was carried out to find a way of resource utilization of the waste from zinc oxide factories.In the paper some factors influencing the effect of leaching ratio including reaction time,temperature,amounts of ammonia, amounts of ammonium acid carbonate hydrogen peroxide , have been investigated and screened out. Through orthogonal tests ,the factors influencing the leaching ratio of zinc oxide fume dust have been investigated including: reaction time, temperature, amounts of ammonia, amounts of ammonium acid carbonate hydrogen peroxide to decide the major influencing factors.Based on the studies,the best process conditions have been gained after single factor optimizing tests of some important factors,that is : reaction time was 1.5-2 hours, temperature was 328-333K, amounts of ammonia were 130-140ml, amounts of ammonia and ammonium acid carbonate hydrogen peroxide ratio was 5.In addition,the experimental data of 20 data points were correlated,taking reaction time, reaction rotation, amounts of ammonia, amounts of ammonia and ammonium acid carbonate hydrogen peroxide ratio as input vector ,and leaching ratio as output vector to set up the whole BP artificial neural networks of leaching ratio,which uses arithmetic,the total mean relative deviation between the 20 train and 5 test aggregate samples compared with the experimental data is 7.8 % and 5.2% respectively.BP artificial neutral network whose structure was 5*16*8*1,the expecting values of the model are in better agreement with the experimental values.Under the above conditions, the zinc oxide by calcination the zinc basic oxide was getted,the purety of zinc oxide product is 97.1%, the specific surface area of zinc oxide product is above 50m2 g-1, and the average particle diameter of zinc oxide product is0.05-0.2 um ,which agreed with the activated zinc oxide national standard.At last,the research of the influence of the temperature on the basic zinc carbonate decomposition ratio has been carried on and the result showed that the reaction rate will increase with temperature increment,and the proper temperature is 540K,also showed that the activated energy of basic zinc carbonate decomposition of different methods were 129. 8KJ mol-1 116. 5 KJ mol-1 136. 68 KJ mol-1,respectively.