【摘要】 以二钼酸铵为原料，采用水溶-蒸发浓缩脱氨-冷却结晶法制备了七钼酸铵。考察了浓缩程度对结晶产物的影响，研究了浓缩液密度、降温速率、养晶时间和搅拌速率对七钼酸铵粒度及形貌的影响。结果表明：二钼酸铵水溶后，通过蒸发浓缩-冷却结晶法可以制备得到物相单一的七钼酸铵晶体；冷却结晶过程控制浓缩液密度1.38 g/cm~3左右、降温速率30℃/h、养晶时间1 h、搅拌速率150 r/min、冷却终温22℃下可得到形貌完整、平均粒度为337.649μm的棱柱状七钼酸铵晶体。更多还原

【Abstract】 Ammonium heptamolybdate was prepared by water dissolving-evaporation concentration removal of ammonia-cooling crystallization method using ammonium dimolybdate as raw material.The effects of concentration degree on crystallization product were investigated, and the effects of concentrated liquid density, cooling rate, crystal growing time, and stirring rate on the particle size and morphology of ammonium heptamolybdate were also studied.The results show that ammonium heptamolybdate crystals with a single phase can be prepared by the evaporation concentration-cooling crystallization method after the water dissolution of ammonium dimolybdate.With a concentrated liquid density of about 1.38 g/cm~3,a cooling rate of 30 ℃/h, a crystal growing time of 1 h, a stirring rate of 150 r/min, and a final cooling temperature of 22 ℃,the crystals of ammonium heptamolybdate are complete in morphology and prismatic with an ave-rage particle size of 337.649 μm in a controlled cooling crystallization process.更多还原