基于Box-Behnken设计优化铝土矿选矿回水处理工艺参数

摘要

Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation, and discharge of backwater brings environmental risk. In this study, methods such as Fenton-oxidation, adsorption and coagulation were used in the treatment of backwater, the flotation indexes were checked after backwater treatments, and Box-Behnken design (BBD) was used in the optimization of the main operating parameters. The results reveal that flotation indexes are effectively improved after coagulation treatment by polyaluminum ferric chloride (PAFC). The optimum parameters predicted by BBD are pH 7.55, 1.09 g/L PAFC dosage and temperature of 25 ℃. Under these optimum conditions, a maximum recovery of Al2O3 of 82.83％and a minimum A/S of 1.30 of tailings are gained, while the deviations are less than 3％from the predicted values. These findings encourage the application of BBD for the optimization of critical parameters in backwater treatment.%随着铝土矿浮选回水循环时间的增加,铝土矿浮选指标逐渐降低,而浮选回水的外排会带来一定的环境风险.采用Fenton氧化、吸附、混凝等方法处理浮选回水,测定处理后浮选回水的浮选指标,并采用Box-Behnken设计(BBD)对主要试验参数进行优化.结果表明,聚合氯化铝铁对混凝处理后的浮选指标有明显的改善作用.BBD预测的最佳参数值为pH 7.55、聚合氯化铝铁用量1.09 g/L、温度25℃.在预测的最佳工艺参数下,精矿氧化铝回收率82.83％、尾矿铝硅比为1.30,结果与预测值的偏差均小于3％,这表明BBD适用于选矿回水处理中关键参数的优化预测.