Technological theory of nanometer-ZnO production in industry.

Abstract

In terms of chemical engineering theory, the operating domain of nanometer ZnO production has been analyzed in detail by means of uniform precipitated method. The reacting system of ZnO production is a complicated system with series, parallel, reversible, and multiphase reactions. The author finds that the independent reaction number is 6. The free degree of the reactions is 7. The proportional ratio of reactants is C(CO(NH2)2):C(Zn(NO3)2) 3.5 : 1. The operating domain is illustrated by the proportional concentrations CO(NH2)2: Zn2+ = 1 : 2.5; Zn2+:H2O=1:11; CO(NH2)2:H2O=1:3. The value of pH is key factor of the reaction system and a better pH value is 6.5. Other key factors are temperature and time of the reactions.