In this work, the precipitation of high-quality calcium carbonate (PCC) from synthetic Ca-rich solutions was investigated. A mixture of Ca and Mg salts were considered to reproduce the chemical composition of leachates obtained from leaching BOF slags with diluted HCl. The effect of adding NaOH and different amine-based organic solvents (PEI, MEA and AEEA) was investigated by considering an integrated process: CO₂-absorption and mineral carbonation. Ca conversion was below 15 wt.% in the absence of alkaline reagents as alkalinity is reduced when H₂CO₃ is formed under permanent introduction of CO₂. The addition of a substantial amount of NaOH (20 g/L, Ca/Na ratio of 1:1) allowed to significantly increase the Ca-conversion yield, and the morphology of calcite particles was modified from scalenohedral-rhombohedral-type to rhombohedral shape by increasing the CO₂-gas flow rate from 0.008 to 0.5 L/min. During carbonation with the addition of amine-based organic solvents, MEA and AEEA showed the highest Ca-conversion, i.e. > 80 wt.%. A combination of vaterite and aragonite particles were produced at 30 °C, while the formation of pure aragonite prevailed when the temperature was increased up to 70 °C. The effect of Mg on the formation of aragonite particles was considered negligible due to the low initial concentration, although some traces of Mg were detected in the corresponding final PCC particles.

在这项工作中，研究了从富含钙的合成溶液中沉淀出高质量的碳酸钙（PCC）。Ca和Mg盐的混合物被认为可重现通过用稀HCl浸出BOF炉渣获得的渗滤液的化学组成。通过考虑以下综合过程，研究了添加NaOH和不同胺基有机溶剂（PEI，MEA和AEEA）的效果：CO ₂吸收和矿物碳酸化。在没有碱性试剂的情况下，Ca转化率低于15 wt。％，因为在永久引入CO _2的情况下形成H ₂ CO ₃时，碱度降低。添加大量的NaOH（20 g / L，Ca / Na比为1：1）可以显着提高Ca转化率，方解石颗粒的形态从斜面-菱面体类型变为菱面体形状通过将CO ₂气体流速从0.008提高到0.5 L / min。在添加胺基有机溶剂的碳酸化过程中，MEA和AEEA的Ca转化率最高，即> 80 wt。％。球°石和文石颗粒的混合物在30°C时产生，而温度升至70°C时，纯文石的形成占主导地位。由于初始浓度低，镁对文石颗粒形成的影响被认为可以忽略不计，尽管在相应的最终PCC颗粒中检测到了一些痕量的镁。