Ca-P-H2O系电位-pH图的研究

黄磷炉渣是采用磷矿、硅石、焦炭通过电炉法经1400-1600℃高温还原生产黄磷时得到的固体废弃物,具有很高的反应活性,其主要成分为硅、钙元素的化合物,采用磷酸浸取时可反应生成水合二氧化硅和可溶性钙盐,以实现硅钙分离,制取有价产品.文中通过热力学计算,绘制了298.15 K下Ca-P-H2O系的电位-pH图,并通过分析发...

Study on potential-pH diagram of Ca-P-H_2O system

Yellow phosphorus slag is a solid waste produced in yellow phosphorus production by electrical furnace reduction from phosphate ore,silex and coke at high temperature of 1 400-1 600 ℃.It has high reactivity,contains a lot of silicon and calcium compounds,and can be applied to the production of valuable products.When yellow phosphorus slag is leached by phosphoric acid,hydrated silica and soluble calcium salt are produced,thus calcium and silicon are separated.The potential-pH diagram of the Ca-P-H2O system at 298.15 K was obtained on the basis of thermodynamic calculation.The results show that the terminal controlled pH of lixivium should be less than 1.39 to make calcium element into the leaching solution,when yellow phosphorus slag is leached with phosphoric acid and the concentration of both calcium ion and phosphoric acid in leaching solution is 1.00 mol/L.The lixivium has lots of calcium element and phosphoric acid or dihydrogen phosphate root,and can be used to produce calcium dihydrogen phosphate,calcium hydrophosphate or tricalcium phosphate by the further neutralization in right pH conditions of the system.