一种废弃镁铬耐火砖浮选尾渣的处理工艺

A Treatment Process for the Flotation Tailings of Discarded Magnesia Chrome Refractory Bricks

采用氯化挥发法对废弃镁铬砖浮选尾渣进行处理。在尾渣成分分析和氯化挥发过程中相关化学反应热力学计算的基础上,研究了焙烧过程中焙烧温度、氯化剂用量、焙烧时间等因素对杂质金属脱除的影响,利用XRD、SEM对焙烧渣的物相和微观形貌进行了表征,并与原尾渣进行了对比。结果表明,确定的最佳工艺条件为:焙烧温度1 000℃、MgCl_2用量12%、焙烧时间0.8 h,在此条件下可将尾渣中Ag、Pb、Bi含量降至0.01%,0.06%和0.10%,挥发率分别达到94.22%,99.09%和96.48%;经处理后焙烧渣的成分与原材料一致,可作为镁铬耐火砖生产原料,实现了二次资源的再利用。

A chloridizing volatilization process was applied into the treatment of flotation tailings of discarded magnesia chrome refractory bricks. Based on the analysis of chemical components of tailings and the relevant thermodynamic calculation of chloridizing volatilization process,effects of roasting temperature,dosage of chloridizing agent and roasting time on removal of metallic impurities were studied. Moreover,the phase and microscopic morphology of the roasting slag were characterized by means of XRD,SEM,which was then compared to the tailings before chloridizing roasting.Results showed that under the following optimal process conditions,including a roasting temperature of 1 000 ℃,dosage of MgCl_2 at 12%,roasting time of 0. 8 h,the contents of Ag,Pb,and Bi in tailings decreased to 0. 01%,0. 06%,and0. 10%,respectively,with the volatilization rate of each at 94. 22%,99. 09% and 96. 48%,respectively. It is found that roasted residues after treatment have the same compositions with raw materials,and can be used as materials for the production of magnesia chrome refractory bricks,thus achieving the recycling the secondary resources.