电石渣矿化CO2-可控制备碳酸钙的实验研究

本文提供了一种以电石渣为原料,循环利用氯化铵制备高纯碳酸钙的方法；通过实验系统讨论了碳酸钙制备的工艺条件以及不同工艺条件对所得碳酸钙晶型与形貌的影响. 结果表明：碳酸钙制备的优化工艺条件为CO2流速 80 mL/min, 反应温度30 °C, 反应时间60 min；所得产物为纳米的球形球霰石,产物中CaCO3的含量为99.95%, 白度为99.3%, 产物具有良好的自流动性和自粉化性；整个制备工艺中碳酸化反应滤液可循环利用8次, 此时的反应效能大于50%；通过工艺条件的调控成功制备出高纯纳米碳酸钙、球霰石型碳酸钙、文石型碳酸钙以及方解石型碳酸钙. 论文提出的研究方案有望应用于电石渣的资源化利用与碳酸钙的可控制备.

Controllable preparation of CaCO3 from carbide slag by CO2 sequestration

In this paper, a method was proposed to prepare high-purity CaCO3 to sequester CO2 by means of the cyclic utilization of ammonium chloride and with carbide slag as the raw material was proposed. There was a systematical discussion about the process conditions for carbonation reaction and the effect of different technological conditions on the property of reaction product. The results have shown that the optimum process conditions for the carbonation reaction were as follows: reaction time: 60 min, reaction temperature: 30 °C, and the flow velocity of CO2: 80 mL/min. The optimum carbonated conversion rate was 98.99%. The resulting product was nanoscale spherical vaterite with a CaCO3 content of 99.95%, a whiteness of 99.3% and good self-fluidity and self-pulverability. The carbonation reaction filtrate could be recycled 8 times throughout the preparation process, and the reaction efficiency at this time was greater than 50%. High-purity nanoscale CaCO3 and fibrous CaCO3 could be successfully prepared by the control of process conditions. The study scheme proposed herein is hopeful to be used to the extraction of CO2 from carbide slag and the controlled preparation of CaCO3.