Department of Mining and Materials Engineering, McGill University, Montreal, QC, Canada.
J Hazard Mater. 2010 Sep 15;181(1-3):526-34. doi: 10.1016/j.jhazmat.2010.05.046. Epub 2010 May 16.
A new stabilization process for scorodite (FeAsO(4).2H(2)O) solids based on the concept of encapsulation by controlled deposition of mineral coatings immune to pH or redox potential variations is described. The stability of the encapsulated scorodite with aluminum phosphates under simulated anoxic and oxic environments is demonstrated. Encapsulation experiments were carried out at 95 degrees C using 50 g/L scorodite in acidic sulphate solution containing 0.16 mol/L of P(V) with Al(III) to P(V) molar ratio of 1 and precipitation pH of 1.7. The encapsulated particles were characterised by XRD, SEM, TOF-SIMS and TOF-LIMS. The coating was crystalline AlPO(4).1.5H(2)O ranging in thickness from 2.5 to 3.5 microm. Encapsulation of scorodite particles with hydrated aluminum phosphate appears to be effective in controlling/suppressing the release of arsenic under both oxic and anoxic conditions by more than one order of magnitude.
一种基于通过控制矿物涂层的沉积来实现包裹以抵抗 pH 值或氧化还原电位变化的概念的辉锑矿（FeAsO4.2H2O）固体的新稳定化方法被描述。在模拟缺氧和有氧环境下，用铝磷酸盐对包裹的辉锑矿的稳定性进行了证明。在 95°C 下，使用含有 0.16 mol/L P(V)的酸性硫酸盐溶液中的 50 g/L 辉锑矿进行包裹实验，Al(III)与 P(V)的摩尔比为 1，沉淀 pH 值为 1.7。用 XRD、SEM、TOF-SIMS 和 TOF-LIMS 对包裹颗粒进行了表征。涂层为结晶态的 AlPO4.1.5H2O，厚度在 2.5 到 3.5 微米之间。用水合铝磷酸盐对辉锑矿颗粒进行包裹，似乎可以有效地在有氧和缺氧条件下将砷的释放控制/抑制一个数量级以上。
