【摘要】 采用间歇结晶法研究了pH值、降温速度、搅拌速度对磷酸二氢铵(MAP)结晶过程的影响。实验结果表明,MAP的溶解度随pH值变化明显,当pH值为3.2时溶解度最小。在pH值为3.2时,结晶速度、晶体析出温度、单晶长径比和平均粒径均为最大,且随着pH值增大,均显著减小;降温速率对于晶形及长径比没有影响,随着降温速度增大,晶体平均粒径减小,介稳区宽度增大,MAP的成核级数约为1.1;搅拌速度加快,结晶诱导时间显著缩短,介稳区宽度变窄。更多还原

【Abstract】 The effects of pH value,cooling rate,agitation rate on the monoammonium phosphate(MAP) crystallization process were studied by means of batch crystallization process.The experiment shows that the solubility changes rapidly with the pH value change,which is the minimum when pH=3.2.The crystallization rate,crystallization temperature,the ratio of length to diameter(l/d) and average size of crystal reach the maximum when pH=3.2,which all decreases gradually with the increase of pH value.With the increase of cooling rate,the average size of MAP crystal decreases and the metastable zone width widens,and the crystal nucleation rate is about 1.1.With the increase of agitation rate,the crystal induction period decreases markedly,and the metastable zone width reduces.更多还原