亚磷酸钙工业废渣制取亚磷酸

Preparation of Phosphorous Acid from Calcium Phosphite Industrial Residue

研究了以亚磷酸钙工业废渣为原料制取亚磷酸的工艺条件。实验确定最佳工艺条件为:在1 500mL去离子水中加入亚磷酸钙工业废渣500.0g和碳酸钠350.0g,80℃反应8h,得亚磷酸钠溶液;向亚磷酸钠溶液中加入163.3g硫酸得到亚磷酸粗产品;加入300mL无水乙酸萃取亚磷酸粗产品后,在蒸馏温度100℃、蒸馏真空度0.08M Pa下蒸馏2h,得到115.6g亚磷酸产品,产率为84.6%,产品纯度达到HG/T2520—93《工业亚磷酸标准》中工业级标准。

The process conditions for preparation of phosphorous acid from calcium phosphite industrial residue were studied. The optimum conditions obtained by the experiments are as follows： Adding 500.0 g calcium phosphite industrial residue and 350.0 g sodium phosphate into 1 500 mL deionized water, reacting at 80 ℃ for 8 h to form the sodium phosphite solution; Adding 163.3 g H2SO4 into the sodium phosphite solution to obtain the crude phosphorous acid; Extracting the crude phosphorous acid with 300 mL acetic acid, then vacuum distilling at 100 ℃ and 0.08 MPa for 2 h, 115.6 g phosphorous acid product is obtained with 84.6% of yield. The purity of the product can meet the industrial grade standards of HG/T2520 -93.