高磷鲕状铁矿酸浸脱磷

研究了酸浸处理高磷铁矿脱磷及其影响因素.实验用鄂西鲕状高磷矿Fe的质量分数为51.7%,P的质量分数约0.5%,S的质量分数为0.34%.通过硫酸浸出,浸出矿中磷的质量分数降低至0.07%左右,而铁损只有0.18%,S的质量分数为0.35%,满足钢铁生产的要求.通过扫描电镜观察和能谱分析表征了高磷矿中磷的脱除,在实验酸度下能明显看出磷灰石溶解,而铁相基本不反应,并得到了热力学计算证明.实验确定了最佳的酸浸条件:浸出时间1 h,液固比100mL:8 g,酸度0.2 mol·L-1,振荡频率150 Hz.通过微波加热预处理,高磷铁矿中产生微裂纹,增加了矿石的比表面积,但是这并没有明显促进酸浸脱磷的进行.通过补酸的方式循环利用酸浸液处理高磷铁矿能得到较好的脱磷效果,脱磷率稳定在80%,能有效减少酸耗、保护环境. 

Phosphorus removal from high phosphorus oolitic iron ore by acid leaching

This paper reports the phosphorus removal of high phosphorus oolitic iron ore by acid leaching and its influence factors. The experimental ore is Exi high phosphorus oolitic iron ore with 0.5% phosphorus, 51.7% iron and 0.34% sulphur. After acid leaching, the P content decreases to about 0.07%, the iron loss during acid leaching is about 0.18%, and the S content is 0.35%, which can meet the requirements of steel production. Through analyzing the ore surface before and after acid leaching by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), it is found that apatite is almost completely dissolved, but iron oxide phase hardly reacts, which is also proved through thermodynamic calculations. The optimal experimental parameters are determined to be the leaching time of 1 h, the liquid-solid ratio of 100 mL:8 g, the acid concentration of 0.2 mol·L-1, and the oscillation frequency of 150 Hz. Micro cracks appear in the ore by microwave preheating, the specific area of the ore is increased, but little improvement in dephosphorization is induced during acid leaching. The recycling of the waste acid solution is feasible. Through adding fresh acid to the waste acid solution, the acid solution after treatment can leach phosphorus to the satisfied extent again. The dephosphorization rate is controlled at 80%. The recycling can reduce the cost obviously and protect the environment.