搅拌釜内氯化钾降温结晶的实验研究

Experimental Research on Cooling Crystallization of Potassium Chloride in Stirred Tank

在50 L结晶罐中,通过降温结晶的方法,提纯KCl固体。采用间歇动态法,考察了搅拌转速、降温速率、搅拌器位置、晶种加入量对KCl晶体过程的粒度分布影响。实验结果表明,以上因素均会对晶体的成核、生长产生影响。操作条件控制在270 r/min、晶种量390 g、冷却水流量0.43 m3/h、搅拌器位置C/H=0.22(C,搅拌器离底高度;H,液位高度),可以得到晶体粒径分布集中、粒径较大的KCl晶体颗粒。

Pure potassium chloride was obtained from saturated solution of potassium chloride, in crystallizer of fifty litres, by means of cooling crystallization. The influences of speed of agitator, rate of cooling, impeller location and amount of crystal seed on crystal size distribution were studied. The experiment results showed that those factors had effect on nucleation and growth of crystals. Crystals of potassium chloride with concentrated distribution and larger particle size were got under the optimum conditions of stirring speed 270 r/min, seed amount 390 g, cooling water flow rate 0.43 m3/h and agitator location C/H=0.22(C, impeller off-bottom clearance;H, liquid level height).