稀土生产废水除杂及酸碱制备试验研究

Experimental Study on Impurity Removal and Preparation of Acid-base from Rare Earth Extraction Wastewater

鉴于萃取废水和碳沉废水目前处理技术的不足导致资源浪费现象,以某稀土公司的萃取废水为试验料液,提出“预处理除杂+双极膜制酸碱”的处理工艺。工艺1:原水→过滤除悬浮物→ORZ树脂吸附→膜过滤→化学软化→过滤→汽提精馏脱氨→树脂软化→螯合树脂→双极膜电渗析制酸碱,双极膜制盐酸、氢氧化钠摩尔浓度分别达到2.25mol/L和2.4mol/L,纯度较高可回用于生产;工艺2:原水→过滤→ORZ树脂吸附→膜过滤→树脂软化除钙镁→螯合树脂除高价离子→双极膜电渗析制酸碱,制备的氨水和盐酸摩尔浓度均可达到2mol/L以上,但制备的氨水中含有钠,无法回用到无钠体系。

In view of the waste of resources caused by the lack of current treatment technology for extraction wastewater and carbon deposition wastewater,this paper took the extraction wastewater of a rare earth company as the test feed liquid,and proposed a treatment process of“pretreatment and impurity removal+bipolar membrane acid-base production”.Process 1:Raw water→filtration to remove suspended solids→ORZ resin adsorption→membrane filtration→chemical softening→filtration→stripping rectification and deamination→resin softening→chelating resin→bipolar membrane electrodialysis to produce acid and alkali.The concentration of hydrochloric acid and sodium hydroxide produced by bipolar membrane reaches 2.25mol/L and 2.4mol/L respectively,and the purity is high and can be reused for production,and the purity was high and could be reused for production;process 2:raw water→filtration→ORZ resin adsorption→membrane filtration→resin softening to remove calcium and magnesium→chelate resin to remove high-valent ions→Bipolar membrane electrodialysis for acid-base production can produce ammonia water and hydrochloric acid with concentrations above 2 mol/L,but the produced ammonia water contains sodium and cannot be reused in a sodium-free system.