普鲁士蓝类钠电池正极生产废水预处理工艺研究

Study on Pretreatment of Wastewater from Positive Electrode Production of Prussian Blue Sodium Batteries

钠离子电池作为新兴产业,有关其生产工艺的研究较多,但是鲜少见到关于钠电池生产废水处理工艺的研究。因此,本文对普鲁士蓝类钠电池正极废水的预处理工艺进行实验研究,探究最佳处理工艺。最终确定了母液废水采用直接氧化法预处理工艺,即先加入H_(2)O_(2)(1.18倍理论投入量),然后用质量分数为30%的NaOH溶液调pH至9左右,静置30 min,再经过管式超滤膜过滤,母液中铁锰元素的去除率分别约为99.93%和99.99%。洗水废水采用两段式沉淀法预处理工艺,即第一阶段采用固氰除铁法,先用质量分数为30%的NaOH溶液调pH至7左右然后加入硫酸亚铁(硫酸亚铁投入量与废水中铁元素质量比为5.2),反应静置30 min。主要去除废水中绝大部分的铁元素和少部分锰元素。在一段处理的基础上再采用氧化沉淀法,先加入H_(2)O_(2)(0.83倍理论投入量),然后用质量分数为30%的NaOH溶液调pH至9,反应静置30 min,再经过管式超滤膜过滤,最终铁和锰元素的去除率分别约为99.87%和99.99%。为实际工程中钠电池废水预处理提供了重要技术参考。

The production technology of sodium ion battery as a new industry has many researches,but there are few researches on the wastewater treatment technology of sodium battery production.Therefore,the pretreatment process of positive electrode wastewater of Prussian blue sodium battery was studied in this paper,and the best treatment process was explored.Finally,the pretreatment process of mother liquor wastewater by direct oxidation method was determined,which included first adding H2 O2(1.18 times the theoretical input)and then adjusting pH to 9 with 30wt%NaOH solution.The removal rate of iron and manganese elements in mother liquor was about 99.93%and 99.99%,respectively.The washing water wastewater was pretreated with a two-stage precipitation method,including the solid cyanide removal method used in the first stage.The pH was adjusted to about 7 with 30wt%NaOH solution,and then ferrous sulfate was added(the input of ferrous sulfate and the mass ratio of iron in the wastewater was 5.2)with the static reaction of 30 min.They mainly remove the most iron element and a small part of the manganese element in the wastewater.Based on one stage of treatment,the oxidation precipitation method was adopted,H2 O2(0.83 times the theoretical input)was added first,and then the pH was adjusted to 9 with 30%NaOH solution,and the reaction was left for 30 min,and then filtered through tubular ultrafiltration membrane.The final removal rates of iron and manganese were about 99.87%and 99.99%,respectively.It provides an important technical reference for the pretreatment of sodium battery wastewater in practical engineering.