黄磷炉渣制备微晶玻璃过程中有害组分的迁移转化预测

Transformation behavior of harmful component in yellow phosphorus slag for preparation of glass-ceramics

为研究利用自然冷却态黄磷炉渣制备微晶玻璃过程中所产生的污染过程,利用Factsage6.4热力学软件并结合自然冷却态黄磷炉渣的化学成分分析结果,计算自然冷却黄磷炉渣制备CaO-Al_2O_3-SiO_2系微晶玻璃时有害组分As、F、P、S 4种元素随温度变化以不同形态存在的规律。结果表明,在自然冷却黄磷炉渣加热至熔融状态过程中,炉渣中As和S元素逐渐达到热力学平衡状态,而F和P则需要更高温度。在高温状态下,体系中S主要以气相SO_2和SO_3存在,P从固态氟磷灰石(Ca_(10)(PO_4)_6F_2)转变为熔融态磷酸钙(Ca_3(PO_4)_2),As存在形态由固态砷酸钙(Ca_3(AsO_4)_2)向气相AsF_3(87.72%)和液态As_2O_3渣相转变,F则以熔融态CaF_2(64.88%)、MgF_2(11.34%)和气相SiF_4存在。并对As元素的迁移转化进行了试验验证,试验测得的结果和理论计算结果有较好的相关性。

In order to study the pollution behavior in the preparation of glass-ceramics by melting method using natural cooling yellow phosphorus furnace slag as main raw material, the thermodynamic equilibrium states of arsenic, fluorine, phosphorus and sulfur elements in the CaO-A1203-SiO2 system were calculated by FactSage6.4 software package combined with the chemical composition analyses of the natural cooling yellow phosphorus furnace slag. The transport and transformation of arsenic, fluorine, phosphorus and sulfur elements were explored at different temperatures. The results show that the arsenic and sulfur elements in the slag gradually reach up to thermodynamic equilibrium state while in the cases of fluorine, phosphorus a higher temperature is required in the process of the slag being heated to molten state. Under high-temperature conditions, sulfur mainly exists as SO2 and SO3 gases; Phosphorus is transformed from fluorine apatite（ Caj0 （ PO4 ） 6F2 ） into molten calcium phosphate （ Ca3 （ PO4 ）2 ） ; the arsenic in the solid Ca3 （ AsO4 ） 2 ） is changed into gaseous AsF3 （87.72%） , and the rest is transformed to As203 in liquid slag phase. The fluoride remains in CaF2 （64. 88% ） , MgF2 （11.34%） both as molten state with a small amount in SiF4 gas. In addition, the experiments are conducted to verify the prediction on arsenic transformation, the results from which are well in agreement with the theorectical calculations.