云母铁珠光颜料制备过程中FeCl3与尿素水解反应动力学

测定了均匀沉淀法制备云母铁珠光颜料过程中FeCl3与尿素水解反应浓度的变化规律，建立了各自的水解速率方程，得出FeCl3水解反应的级数α1为0．9级，其活化能Ea1为125．5kJ／mol；尿素水解反应的级数α2为0级，其活化能Ea2为252．8kJ／mol．通过对尿素与FeCl3的水解速率方程进行分析，得出一次加入尿素、连续加入铁盐的新加料方法，可使云母铁珠光颜料制备过程反应液的pH值恒定．

Hydrolysis Kinetics of Ferric Chloride and Urea during the Preparation of Iron Coated Mica Titania Pigments

The concentration changes of FeCl3 and urea were determined during preparing mica iron nacreous pigment by homogeneous precipitation with urea as precipitating agent, and the hydrolysis kinetic equations were deduced respectively. The hydrolysis reaction of FeCl3 is of 0.9 order with activation energy about 108.76 kJ/mol and preexponential factor about 1.841016 g0.1/(kg0.1min); the hydrolysis of urea is of 0 order with activation energy about 252.8 kJ/mol and preexponential factor about 1.331033 min-1. By analyzing hydrolysis kinetic equations of FeCl3 and urea, a new feeding method that urea is added at the starting and iron salt is fed continuously was presented for preparing mica iron nacreous pigment by homogeneous precipitation with urea as precipitating agent so as to keep pH constant during the preparation.