KR脱硫渣中鳞片石墨的回收

铁水脱硫过程中溶于铁水中的过饱和碳会以石墨的形式析出，本文针对铁水脱硫渣中含有石墨的特点，以煤油为捕收剂，2^#油为起泡剂，采用浮选法进行回收，同时采用球磨、磁选对回收的石墨进行物理除杂，然后用盐酸、氢氟酸混酸进行化学提纯，制备得高纯鳞片石墨。研究表明：石墨回收率随着浮选剂投加量的增加先增加后减小，在煤油和2^#油总投加量为1200 g/t、煤油∶2^#油= 4∶1时，回收率超过97%；球磨使杂质从石墨表面剥离，磁选则降低石墨中的含铁物质，“球磨+磁选”处理可以使显著降低石墨中杂质含量，通过三次“球磨+磁选”后，石墨中的固定碳含量由58%提高到88%以上。混酸处理在较佳条件下可以将石墨的灰分降至0.03%，达到高纯石墨标准。扫描电镜分析表明回收的鳞片石墨与天然鳞片石墨在外形和结构上均无明显差异。

Recovery of Flake Graphite from KR Desulfurization Slag

In the desulfurization process of molten iron, the supersaturated carbon dissolved in molten iron precipitates in the form of graphite. In this paper, according to the characteristics of graphite contained in molten iron desulfurization slag, the flotation method was firstly used to recover the graphite with kerosene used as collector and No.2 oil used as foaming agent, and then the ball milling and magnetic separation process was used to physically remove the impurities of the recovered graphite, and finally the hydrochloric acid and hydrofluoric acid were used for chemically purification. With the result, high purity flake graphite was prepared. The results show that the graphite recovery firstly increases and then decreases with the increase of flotation agent dosage. When the total dosage of kerosene and No.2 oil is 1200 g/t and w (kerosene: No.2 oil) = 4:1, the recovery is more than 97%. The ball milling treatment separated the impurities from the graphite surface, while the magnetic separation reduced iron content in graphite. After three times of the ball milling and magnetic separation treatment, the fixed carbon content in graphite increases from 58% to more than 88%. Under the optimum conditions, the ash content of graphite can be reduced to 0.03% by mixed acid treatment, reaching the standard of high purity graphite. SEM analysis also showed no significant difference in shape between the recovered flake graphite and the natural flake graphite.