乙醇溶析结晶法从白炭黑废母液中回收硫酸钠

Recovery of Sodium Sulfate from Waste Mother Liquor in Silica Production by Solventing-out Crystallization with Ethanol

以乙醇为溶析剂,通过过滤—中和—蒸馏浓缩—溶析结晶等工序,从白炭黑废母液中回收硫酸钠。考察了硫酸钠回收效果的影响因素,并进行了热能消耗和处理成本的分析。实验结果表明:乙醇的加入量对硫酸钠溶解度和蒸馏浓缩过程有着显著影响;在蒸馏醇水比(乙醇与中性废母液的体积比)为0.27,浓缩废母液中硫酸钠质量浓度为69.27 g/L,溶析醇水比(乙醇与浓缩废母液的体积比)为1的最佳工艺条件下,白炭黑废母液中硫酸钠的一次回收率可达69.94%,硫酸钠产品的纯度达到97.3%。

Using ethanol as solventing-out agent,Na2SO4 was recovered from waste mother liquor in silica production by the process of filtration-neutralization-distillation concentration-solventing-out crystallization.The factors affecting the recovery effect were studied,and the thermal energy consumption and treatment cost were evaluated.The experimental results show that：The dosage of ethanol has significant influence on Na2SO4 solubility and distillation concentration process; Under the optimum process conditions of ethanol-water ratio in distillation process （the volume ratio of ethanol to the neutral waste mother liquor） 0.27,Na2SO4 mass concentration in concentrated waste mother liquor 69.27 g/L and ethanol-water ratio in solventing-out process （the volume ratio of ethanol to concentrated waste mother liquor） 1,the primary recovery rate of Na2SO4 from the waste mother liquor in silica production can reach 69.94％ with 97.3％ of product purity.