种分过程添加剂对氢氧化铝粒度强度的影响

Effect of Additives on Particle Size and Strength of Aluminum Hydroxide Decomposed with Seed Crystal Used

在铝酸钠溶液的种分过程中,添加剂的应用可以提高产品氢氧化铝的粒度、强度·选出了增大氢氧化铝粒度的添加剂H1,I,F,G,提高氢氧化铝强度的添加剂L,I,F,G,H2,H3,H5;研究了氢氧化铝粒度与强度的关系·结果表明,氢氧化铝颗粒在45～105μm的个数百分数越大,氢氧化铝颗粒分布越均匀,强度就越好;探讨了添加剂的作用机理,即表面活性剂分子的亲油基在氢氧化铝粒子表面形成油层,将氢氧化铝细粒子紧密粘结在一起,使氢氧化铝的粒度与强度增大·

In the decomposition process of sodium aluminate solutions with seed crystal added into it, first relevant additives can play an important role in improving the particle size and strength of product, i.e., aluminate hydroxide. The additives used were divided into two kinds: one was used to increase the products particle size, including the additives H_1,F,I and G, the other was to improve the strength, including L,I,F,G,H_2,H_3 and H_5. The relationship between the particle size and strength of the product was investigated. The results show that the higher the percentage of number of particles with size from 45 to 105?μm is, the higher the strength will be, as well as more even particle distribution. The mechanism of additives as discussed revealed that on the surface of Al(OH)_3 particles the oleophilic group of surface active agent will form oil films to bind together fine Al(OH)_3 particles closely so as to increase both the particle size and strength.