在酸性条件下,用硫化钠作还原剂和沉淀剂,还原-沉淀脱除普通工业品羟基亚乙基二膦酸(HEDPA)中的杂质砷。系统考察了硫化钠加入量、溶液pH、反应温度、反应时间、搅拌速度等因素对脱砷效果的影响,其适宜反应工艺条件为:n(硫化钠)∶n(砷)=4∶1,pH=0.5,反应温度50℃,反应时间2h,搅拌速度90r/min。在该工艺条件下脱砷率达99.3%,可制得高品质低含量砷羟基亚乙基二膦酸(HEDPA),其砷的质量浓度为0.28mg/L,可广泛用作日用化学品添加剂和药物合成的原料。 Under acidic conditions, sodium sulfide is used as a reducing agent and a precipitating agent to reduce and precipitate the impurity arsenic in the conventional industrial hydroxyethylidene diphosphonic acid (HEDPA). The effects of sodium sulfide dosage, pH value, reaction temperature, reaction time and stirring speed on the arsenic removal efficiency were systematically investigated. The suitable reaction conditions were n (sodium sulfide): n (arsenic) = 4:1, pH = 0.5, reaction temperature 50 ℃, reaction time 2h, stirring speed 90r / min. Arsenic hydroxyethylidene diphosphonic acid (HEDPA) with high quality and low content can be obtained with arsenic removal rate of 99.3% under this process condition. The arsenic concentration is 0.28mg / L, which can be widely used as daily chemicals Additives and pharmaceutical raw materials.