机械力化学活化滑石处理含铜废水研究

Mechanochemical Activation of Talc for Disposing Cu;Contaminated Sewage

为提升天然黏土矿物在环境修复领域的实际应用水平,特别是针对重金属污水的治理,对天然滑石矿物进行机械力化学活化,并考察其对含铜废水的净化性能。系统探讨了行星式球磨机的磨机转速、滑石用量、处理时间、溶液中铜离子浓度和铜盐种类等因素对滑石沉淀铜离子效果的影响,同时采用XRD、FTIR等测试手段对滑石及活化样品处理铜溶液前后残渣进行表征,来明晰滑石与铜离子之间的相互作用机理。结果表明,当球磨机转速为500r/min、滑石用量为2.5 g/L、溶液中铜离子浓度为1 000 mg/L时,滑石对铜离子的处理量可达到271.2 mg/g,证实了机械力化学活化可以提高滑石净化含铜废水的处理能力。XRD和FTIR分析结果表明,机械力化学活化后,滑石矿物的完整结晶被破坏,呈现非晶状态,镁离子和羟基从矿物中脱出至溶液中,提高了溶液p H值,在硫酸根离子存在的情况下使铜转化为碱式硫酸铜沉淀从而被去除。该沉淀经简单的酸浸,即可使铜溶出,可作为铜金属资源进行回收。研究表明,机械力化学活化可以切实提高天然滑石矿物的理化反应活性,实现重金属污水净化和金属二次资源回收的双重目的,促进了资源与环境的协同发展。

In this study,mechanochemical activation on talc was conducted as an example of boosting the practical application of natural clay minerals for environmental remediation,especially for the treatment of heavy metal-contaminated sewage. Removal of Cu^(2+) from the aqueous solution by the activated talc was performed wherein,the effects of the rotational speed of the planetary mill,the dose of talc,initial concentration of Cu^(2+),contact time and different anions species were systematically investigated. In the meanwhile,analytical techniques including XRD and FTIR were employed to characterize the talc and the activated samples before and after treating Cu^(2+),thus to provide more insights into the interaction mechanism between talc and Cu^(2+). It was found that,on the conditions of rotational speed of 500 r/min,talc dosage of 2. 5 g/L,initial concentration of Cu^(2+)of 1 000 mg/L,the removal capacity of Cu^(2+) could reach up to 271. 2 mg/g,demonstrating the enhanced processing capacity for heavy metals of mechanochemically activated talc. More importantly,characterizations of XRD and FTIR confirmed that the crystal structure of talc was distorted during mechanochemical activation process,resulting in the amorphization of talc and the subsequent releasing of magnesium cations and hydroxyl group from the talc surface,thereby to react with Cu^(2+) ions in the presence of SO42-anions and then form basic copper sulfate precipitate. By simply acidic leaching,copper may be resolved from the precipitate and then recycled. These findings demonstrate the significantly boosted reactivity of talc by mechanochemical means,which may be utilized to simultaneously decontaminate the heavy metals in sewage and serve as the raw materials for metal resources,as well as to promote the synergic development of resources and environment.