低砷羟基亚乙基二膦酸的制备研究

Preparation of 1-Hydroxyethylidenediphosphonic acid (HEDPA)with low low concentration of arsenic

摘要:

在酸性条件下，采用硫化钠做还原剂和沉淀剂，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值、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：硫化钠与砷的物质的量之比为4:1，溶液的pH值为0.5，反应温度为50℃,反应时间为2h，搅拌速度为90rpm。在此工艺条件下脱砷率达99.3%，可制得高品质低砷羟基亚乙基二膦酸（HEDPA），其砷含量为0.28mg/L，可广泛用做日用化学品添加剂和药物合成的原料。

Abstract:

With sodium sulfide as a reducing reagent and a precipitant in acidic condition, the removal of arsenic (As (III) and As (V)) from industrial 1-Hydroxyethylidenediphosphonic acid (HEDPA) is carried out by a reduction-precipitation method. The purpose is to obtain the effect the quantity of the sodium sulfide, pH value of the solution factors, temperature, time, and mixing speed on de-arsenic. The result shows that the optimal temperature, pH, mole ratio of sodium sulfide to arsenic species and agitation rate are 50℃, 0.5, 4:1 and 90rpm, respectively. After 2h under the selected conditions, the corresponding concentration of arsenic species in HEDPA and efficiency of arsenic removal are 0.28 mg•L-1 and 99.3%, respectively. HEDPA treated by the procedure can serve as detergent & cosmetics additives and raw materials for synthesis of drugs.