石灰铝法的除氯效果及反应机制对比分析  

Comparative Analysis of Chloride Removal Effect and Reaction Mechanism of Lime-aluminum Method

作　　者：陈承启 程明权 赵晓丹 周振 Chen Chengqi;Cheng Mingquan;Zhao Xiaodan;Zhou Zhen(Sinopec Shanghai Gaoqiao Petrochemical Co.,Ltd.,Shanghai 200129,China;Shanghai University of Electric Power,Shanghai 201306,China)

机构地区：[1]中国石化上海高桥石油化工有限公司,上海200129 [2]上海电力大学,上海201306

出　　处：《广东化工》2024年第13期17-20,共4页Guangdong Chemical Industry

基　　金：中国石化上海高桥石油化工有限公司科技项目(S0-23-49-1001)。

摘　　要：采用石灰铝法处理脱硫废水中的氯离子,以大孔拟薄水铝石和偏铝酸钠作为铝盐,对比分析了反应时间、药剂投加量、反应温度等条件对除氯效果的影响及两种铝盐的作用机制。结果表明:反应温度在除氯反应中起决定性作用,当反应温度约为55℃时,在氧化钙溶解产生的碱性环境与反应温度的双重作用下,大孔拟薄水铝石水解产生羟基(-OH)形成Al(OH)_(4)^(-),并与Ca^(2+)结合去除Cl^(-),反应沉淀物主要为Ca_(4)Al_(2)O_(6)Cl_(2)·10H_(2)O和Ca(OH)_(2),Cl^(-)去除率约为55.9%。偏铝酸钠除氯反应的适宜温度区间为30℃~40℃,Cl^(-)去除率最高可达57.9%,且除氯反应速度快于大孔拟薄水铝石。偏铝酸钠进入除氯体系中迅速水解产生Al(OH)_(4)^(-),同时氧化钙发生溶解再沉淀,二者迅速捕捉反应体系中的Cl^(-),反应沉淀物主要为Ca_(4)Al_(2)H_(0.36)O_(6.34)C_(l1.67)、Ca_(4)Al_(2)O_(6)Cl_(2)·10H_(2)O、Ca_(2)Al(OH)_(7)·3H_(2)O和Ca(OH)_(2)。In this study,the lime-aluminum method was used to treat chloride ions in desulphurization wastewater,and macroporous pseudo-boehmite and sodium meta-aluminate were used as aluminum salts,and the effects of the conditions such as reaction time,dosage of chemicals,and reaction temperature on the efficiency of chloride removal,as well as the mechanisms of the two aluminum salts were comparatively analyzed.The results show that the reaction temperature plays a decisive role in the reaction.When the reaction temperature is about 55℃,under the dual effects of the alkaline environment generated by the dissolution of calcium oxide and the reaction temperature,the hydrolysis of macroporous pseudo-boehmite produces hydroxyl(-OH)to form Al(OH)_(4)^(-),and combines with Ca^(2+)to remove Cl^(-),and the reaction precipitates mainly consist of Ca_(4)Al_(2)O_(6)Cl_(2)^(-)·10H_(2)O and Ca(OH)_(2),and the Cl^(-)removal rate is about 55.9%.The suitable temperature range for sodium meta-aluminate is 30℃~40℃,and the maximum Cl^(-)removal rate can reach 57.9%,and the reaction speed is faster than that of macroporous pseudo-boehmite.Sodium meta-aluminate is rapidly hydrolyzed to produce Al(OH)_(4)^(-)in the system of chloride removal,while calcium oxide is dissolved and reprecipitated,and both of them rapidly capture the Cl^(-)in the reaction system,and the reaction precipitates are mainly Ca_(4)Al_(2)H_(0.36)O_(6.34)Cl_(1.67),Ca_(4)Al_(2)O_(6)Cl_(2)·10H_(2)O,Ca_(2)Al(OH)_(7)·3H_(2)O and Ca(OH)_(2).

关 键 词：石灰铝法 大孔拟薄水铝石 氯离子 Al利用率 反应机制 

分 类 号：TQ[化学工程]