A systematic investigation on the interaction between Bayer red mud particles generated from Chinese diaspore bauxite and commercial sodium polyacrylate(SPA) or polyacrylamide(PAM) was performed by red mud settling te...A systematic investigation on the interaction between Bayer red mud particles generated from Chinese diaspore bauxite and commercial sodium polyacrylate(SPA) or polyacrylamide(PAM) was performed by red mud settling tests,conductivity-pH titration and Ubbelodhe viscosimetric measurement.The results indicate that the treatment with red mud by SPA gives a lower red mud settling rate and lower supernatant turbidity than the treatment with red mud by PAM.There is an optimum polymer dosage of 300 g/t(based on the weight of dry red mud) when red mud slurry is treated by SPA or PAM,so 'bridging' adsorption is one of the main interactions between red mud and SPA or PAM.With the increase of NaOH concentration,the hydrolysis degree of PAM dissolved in NaOH solution increases and its molecular weight almost does not change,but the settling rate of red mud treated by it drops rapidly.The settling rate of red mud treated by PAM dissolved in 10 g/L NaOH solution is 0.61 m/h while by PAM dissolved in distilled water it is 1.31 m/h,because the adsorption ability of the hydrolyzed PAM onto red mud surface declines primarily due to the formation of-CONH2～-COO-～-CONH2 intramolecular hydrogen bond。展开更多
采用均相水溶液聚合法,以新型水溶性低温偶氮化合物VA-044作为引发剂合成用于赤泥沉降的聚丙烯酸钠絮凝剂。通过正交优化实验确定聚丙烯酸钠合成的最佳条件为:反应温度40℃;引发剂用量0.06%;单体浓度40%;链转移剂0.0002%。该条件下制得...采用均相水溶液聚合法,以新型水溶性低温偶氮化合物VA-044作为引发剂合成用于赤泥沉降的聚丙烯酸钠絮凝剂。通过正交优化实验确定聚丙烯酸钠合成的最佳条件为:反应温度40℃;引发剂用量0.06%;单体浓度40%;链转移剂0.0002%。该条件下制得的聚合产物特性粘数可达到1050 m L·g-1。采用红外光谱对合成产物进行检测,红外图谱显示聚合产物为聚丙烯酸钠。通过赤泥沉降实验测试其絮凝性能,结果表明自制絮凝剂SP1最佳沉降速度可达到44.18 m·h-1,总体絮凝效果优于Alclar 665絮凝剂。展开更多
基金Supported by National Basic Research Project (973) of China (No.2005CB623702)
文摘A systematic investigation on the interaction between Bayer red mud particles generated from Chinese diaspore bauxite and commercial sodium polyacrylate(SPA) or polyacrylamide(PAM) was performed by red mud settling tests,conductivity-pH titration and Ubbelodhe viscosimetric measurement.The results indicate that the treatment with red mud by SPA gives a lower red mud settling rate and lower supernatant turbidity than the treatment with red mud by PAM.There is an optimum polymer dosage of 300 g/t(based on the weight of dry red mud) when red mud slurry is treated by SPA or PAM,so 'bridging' adsorption is one of the main interactions between red mud and SPA or PAM.With the increase of NaOH concentration,the hydrolysis degree of PAM dissolved in NaOH solution increases and its molecular weight almost does not change,but the settling rate of red mud treated by it drops rapidly.The settling rate of red mud treated by PAM dissolved in 10 g/L NaOH solution is 0.61 m/h while by PAM dissolved in distilled water it is 1.31 m/h,because the adsorption ability of the hydrolyzed PAM onto red mud surface declines primarily due to the formation of-CONH2～-COO-～-CONH2 intramolecular hydrogen bond。
文摘采用新型Gemini乳化剂与OP-10复配,Isopar M为油相合成聚丙烯酸铵乳液,研究了HLB值、引发剂用量、单体浓度、EDTA添加量、聚合温度与时间等因素对单体转化率及聚合物特性黏度的影响。结果表明:控制单体的质量分数为45%,在HLB值为8、引发剂(V50)浓度占单体浓度的0.15%、EDTA浓度为0.3%、聚合温度50℃、时间6 h条件下,合成效果最佳。在最佳条件下,乳液的油水比达到1∶3,单体转化率达到97.44%,特性粘度为885.45 m L/g,且赤泥沉降效果良好。
文摘采用均相水溶液聚合法,以新型水溶性低温偶氮化合物VA-044作为引发剂合成用于赤泥沉降的聚丙烯酸钠絮凝剂。通过正交优化实验确定聚丙烯酸钠合成的最佳条件为:反应温度40℃;引发剂用量0.06%;单体浓度40%;链转移剂0.0002%。该条件下制得的聚合产物特性粘数可达到1050 m L·g-1。采用红外光谱对合成产物进行检测,红外图谱显示聚合产物为聚丙烯酸钠。通过赤泥沉降实验测试其絮凝性能,结果表明自制絮凝剂SP1最佳沉降速度可达到44.18 m·h-1,总体絮凝效果优于Alclar 665絮凝剂。
