瓜尔胶改性沉降剂对湿法磷酸下游料浆沉降性能的影响

Influence of guar gum modified settling agent on slurry downstream performance of wet-process phosphoric acid

湿法磷酸广泛应用于下游食品磷酸和磷铵的生产,在这两种产品生产过程中产生的萃余酸和氨化料浆需要通过沉降手段进行净化除杂。采用瓜尔胶改性沉降剂对湿法磷酸下游料浆萃余酸和氨化料浆进行沉降。探究了沉降剂用量、分散时间和沉降温度等条件对沉降剂使用效果的影响,对比了瓜尔胶改性沉降剂与常规聚丙烯酰胺的沉降效果。结果表明,需联合使用氧化硅吸附聚合瓜尔胶复合物和阴离子型瓜尔胶改性沉降剂实现萃余酸的沉降,最佳用量分别为400 g/t和10 g/t,最佳分散时间分别为70 s和150 s;单一阳离子型瓜尔胶改性沉降剂即可实现氨化料浆的沉降,最佳用量为8 g/t,最佳沉降温度为70℃、最佳分散时间为60 s。

Wet-process phosphoric acid has been widely used in the production of food phosphoric acid and ammonium phosphate.The raffinate acid and ammoniated slurry generated during production of these two products need to be purified and removed by sedimentation.In this paper,the sedimentation characteristics of guar gum modified settling agent on raffinate acid and ammoniated slurry were studied.The influence of the amount of settling agent,dispersion time and sedimentation temperature on the settling effects was investigated,and the settling effect of guar gum modified settling agent and conventional polyacrylamide were compared.The results show that it is necessary to use silica adsorption-polymerized guar gum complex and anionic guar gum modified settling agent to realize residual acid sedimentation.The optimal dosage is 400 g/t and 10 g/t,and the optimal dispersion time is 70 s and 150 s,respectively.A single cationic guar gum modified settling agent can achieve the sedimentation of the ammoniated slurry.The optimal dosage is 8 g/t,the best sedimentation temperature is 70℃,and the best dispersion time is 60 s.