【作者】 王黎迟； 蒋文明； 刘富初； 樊自田；

【Author】 WANG Li-chi;JIANG Wen-ming;LIU Fu-chu;FAN Zi-tian;State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology;

【机构】 华中科技大学材料成形与模具技术国家重点实验室；

【摘要】 湿法再生水玻璃旧砂可以得到高质量的再生砂,但会产生大量碱性污水,造成二次污染。目前湿法再生污水的处理方法为加酸中和后絮凝过滤,但该方法处理后的出水中含盐量过高,直接排放仍然会造成环境问题。本文介绍了一种回收碱性物质的水玻璃旧砂湿法再生方法。该方法将水玻璃旧砂和清水(或过滤后的污水)混合,超声处理一定时间后进行气压脱水,得到湿砂和再生污水;然后用占旧砂质量7.5%的清水(或过滤后的污水)淋洗湿砂3次,每次淋洗后都进行气压脱水,得到湿再生砂和淋洗污水;将湿再生砂干燥即得到再生砂,污水经过滤后可直接用于下一批旧砂的再生。采用该方法,湿法再生的脱膜率在80%以上,平均用水量不超过旧砂质量的15%,同时排出的污水可进行碱回收,实现污水零排放。更多还原

【Abstract】 Wet reclamation of waste sodium silicate sands produces reclaimed sands of high quality, and a large amount of alkaline sewage, which leads to secondary pollution. At present, the sewage is subject to the following processing stages: neutralizing, flocculating and filtrating. However, the salinity of the effluent is high and the direct discharge of the effluent will still cause environmental problems. In this paper, a method of wet reclamation of waste sodium silicate sands for alkali recovery was studied. Firstly, the waste sodium silicate sands and fresh water or filtered sewage were mixed. Then after ultrasonic treatment for a certain period of time, air pressure dehydration was carried out to obtain dewatered sands and reclamation sewage. Then the dewatered sands were washed 3 times with water or filtered sewage(7.5% of the waste sands by weight), and after each washing air pressure dehydration was carried out to get dewatered sands and washing sewage. At last the dewatered sands were dried to obtain reclaimed sands. And the sewage could be directly used for the wet reclamation of the next batch of waste sodium silicate sands after being filtered. With this method, the de-skinning rate of wet reclamation was above 80%, and the average water consumption did not exceed 15% of the waste sands by weight. At the same time, the sewage could be used for alkali recovery to achieve zero discharge of sewage.更多还原