1results about How to "Adjust pH value" patented technology

This invention provides a method for preparing nano-calcium carbonate, comprising the following cyclical processes: (1) pretreatment of dry carbide slag raw materials; (2) leaching Ca from the dry carbide slag with ammonium chloride solution. 2+ And perform solid-liquid separation to obtain a high-purity calcium chloride solution and ammonia. (3) Use the ammonia in (2) to absorb low-concentration CO2 flue gas to obtain a mixed solution of ammonium carbonate and ammonium bicarbonate; (4) Mix the mixed solution of ammonium carbonate and ammonium bicarbonate obtained in (3) with the calcium chloride solution obtained in (2) to obtain calcium carbonate precipitate and ammonium chloride solution; (5) Use the ammonium chloride solution obtained in (4) to evaporate and concentrate, and return to step (2) to complete the entire cycle process. This method uses the escaped ammonia produced by the traditional ammonium chloride leaching CO2 to dry carbide slag to absorb flue gas to prepare ammonium carbonate and ammonium bicarbonate. It not only achieves efficient conversion of low-concentration flue gas CO2, significantly reduces conversion costs, and improves economic feasibility, but also uses the high-concentration ammonium carbonate of the conversion product to produce nano-CaCO3, which has significant environmental and economic benefits.