以工业固废磷石膏、CO₂为原料,采用"相转移-沉淀法"制备纳米CaCO₃并考察其碳化工艺条件。结果表明,适宜的复合晶形控制剂及其配比为2.5% STPP+0.5% PDS;适宜的碳化沉淀反应工艺条件为:复合晶形控制剂添加质量分数为3%、碳化终点pH为12.40、碳化反应温度为15℃、陈化时间为0 min。该条件下所制备的纳米CaCO₃样品为纯相方解石型CaCO₃,样品的平均粒径约30 nm,分散性好且粒度较为均匀。晶形控制剂在纳米CaCO₃形成的作用机制为PDS的模板诱导作用,以及Ca²⁺与晶型控制剂水解产生的磷酸根间鳌合、电离所形成的P₃O^5-₁₀离子在CaCO₃晶核上的选择性吸附等的协同作用,有效抑制了CaCO₃晶粒的生长及其颗粒间团聚,促进了粒径小、粒度均匀、分散性好的纳米CaCO₃的形成。

A "phase transfer-precipitation method" is employed to prepare nano-CaCO₃ from phosphogypsum,an industrial solid waste,and CO₂,and study the carbonization process conditions.It is found through screening experiments that the formula of suitable compound crystal shape control agent is 2.5% STPP+0.5% PDS.Through the single factor experiment,the optimum carbonation precipitation reaction conditions are determined as follows:the adding amount of compound crystal shape control agent is 3%,the final pH value of carbonation is 12.40,the carbonization reaction temperature is 15℃,and the aging time is 0 mi.The nano CaCO₃ sample prepared under these conditions is pure phase calcite CaCO₃,and has an average particle size of about 30 nm,showing a good dispersion and uniform particle size.It is concluded that the mechanism of the crystal control agent in the formation of nano-CaCO₃ may be the synergistic effects formed by the template induction of PDS,the chelation between Ca²⁺ and phosphate radical generated in the hydrolysis of crystal control agent,and the selective adsorption of P₃O^5-₁₀ ions formed by ionization on the nucleus of CaCO₃,which can effectively inhibit the growth of CaCO₃ grains and the agglomeration between grains,and promote the formation of nano-CaCO₃ with small particle size,uniform particle size and good dispersion.

涂新悦(1999-),女,硕士生,研究方向为无机材料的制备,2900207568@qq.com