五元杂环类添加剂对铝酸钠溶液种分过程的影响

Effect of five-membered heterocycles additive on seeded precipitation of sodium aluminate solution

选用五元杂环类化合物作为探针分子，在αK=1．40，t=-75℃，c（Na2O）=140g／L，搅拌速度140r／min，晶种添加量为80g／L实验条件下，研究添加剂用量和种类对铝酸钠溶液种分过程分解率和产品氢氧化铝粒度分布的影响，并结合Materials Studio软件中的Dmol3程序对探针分子核糖、四氢糠醇和四氢呋喃进行几何优化计算，计算优化几何构型、总能量、原子净电荷数等。结果表明，随着探针分子杂环上羟基个数的增加，添加剂对铝酸钠溶液种分过程的作用由明显的促进作用转变成明显的抑制作用，探针分子中氧原子净电荷数的绝对值越大，则对溶液分解的抑制作用越强。

Five-membered heterocycles additives were adopted as probe molecule in seeded precipitation process. The effect of the dosage and type of addtives on the decomposition ratio of sodium aluminate solution and particle size distribution （PSD） of gibbsite was investigated, on the condition of initial αK 1.40, temperature 75 ℃, sodium hydroxide concentration 160 g/L, agitation speed 140 r/min and the quantity of crystal seed 80 g/L. The molecular geometries, total energy, net atomic charges etc. of Ribose, THFA and THF were obtained using Dmol3 procedure of software Materials Studio. The results indicate that the effect of the additives changes from promoting effect to inhibitory effect when the number of hydroxyl increases. The inhibitory effect is obviously when the absolute value of oxygen atomic charge increases.