以高镁磷尾矿为原料,采用碳化法对高镁磷尾矿中的磷、镁、钙进行分离,经过煅烧、消化、碳化、热解处理等工序得到碱式碳酸镁和磷精矿。实验结果表明：将高镁磷尾矿煅烧后的消化料浆先进行常压碳化然后进行加压碳化,加压碳化条件为料浆氧化镁质量浓度为12.0~13.5 g/L、二氧化碳分压为0.18 MPa、碳化终点温度为25 ℃,在此条件下镁的回收率达到87%~90%,得到的磷精矿五氧化二磷质量分数达到28%~30%,磷的回收率为60%~65%;将两步碳化后得到的重镁水进行热解,热解条件为重镁水氧化镁质量浓度为10~12 g/L、真空度为0.085 MPa、热解温度为60 ℃、热解时间为50 min,在此条件下所得滤液氧化镁质量浓度为0.7 g/L,镁的回收率为93%。以高镁磷尾矿为原料,采用碳化法制得碱式碳酸镁,经分析产品质量符合HG/T 2959—2010《工业水合碱式碳酸镁》的要求。采用碳化法处理高镁磷尾矿,磷、镁回收率高。此方法为中国高镁磷尾矿的回收利用提供了一条行之有效的技术途径。

Using high-magnesium phosphate tailings as raw materials,the carbonization method was used to separate phospho-rus,magnesium,and calcium in the phosphate tailings,and basic magnesium carbonate and phosphate concentrates were ob-tained through processes such as calcination,digestion,carbonization,and pyrolysis treatment.The experimental results sho-wed that the digested slurry after calcining the high-magnesium phosphate tailings was firstly carbonized at atmospheric pre-ssure and then carbonized under pressure.The conditions of the pressure carbonization were that the mass concentration of the slurry was 12.0~13.5 g/L and the partial pressure of carbon dioxide was 0.18 MPa,carbonization end temperature was 25 ℃, under these conditions the recovery rate of magnesium reached 87%~90%,the mass fraction of phosphorus pentoxide obta-ined from the phosphate concentrate reached 28%~30%,and the recovery rate of phosphorus was 60%~65%;The heavy magnesium water obtained after two-step carbonization was pyrolyzed.The pyrolysis conditions were that the mass concentra-tion of heavy magnesium water was 10~12 g/L,the vacuum degree was 0.085 MPa,the pyrolysis temperature was 60 ℃,and the pyrolysis time was 50 minutes,the mass concentration of magnesium oxide in the filtrate obtained under these conditions was 0.7 g/L,and the recovery rate of magnesium was 93%.Using high-magnesium phosphate tailings as raw materials,basic magnesium carbonate was prepared by carbonization method.The quality of the product was analyzed to meet the requirements of HG/T 2959—2010 “Industrial Hydrated Basic Magnesium Carbonate”.The carbonization method was used to treat high-magnesium phosphorus tailings,and the recovery rate of phosphorus and magnesium was high.This method provided an effec-tive technical approach for the recovery and utilization of high-magnesium phosphate tailings in China.