球磨活化滑石处理含镍废水

    Ball-milling of Talc for Disposing Ni2+ Contaminated Sewage

    • 摘要: 为实现对水中重金属镍离子的有效固定与去除,同时回收镍金属二次资源,本研究以天然滑石矿物为原料,通过简单的机械力球磨手段对其进行活化,实现了水中镍离子的高效固定。本文系统研究了球磨强度、滑石投加量和重金属初始浓度等因素对镍离子固定效果的影响,同时通过对反应前后固体试样进行XRD、FTIR、SEM-EDS等表征,明确了滑石固定镍离子的反应机制。结果表明,球磨活化对滑石沉淀重金属能力具有显著提升效果。主要的反应机制在于,球磨活化导致滑石晶体结构缺陷,OH-和Mg2+自其结构中大量溶出,且相互促进,OH-与溶液中的Ni2+反应生成非晶态的Ni(OH)2沉淀负载于滑石矿物表面,相比于简单吸附过程具备更效率,在球磨转速500 r/min、初始镍(Ni2+)浓度1 000 mg/L条件下,镍离子固定量达到198 mg/g,是未处理的滑石矿物原料的10倍。本研究为重金属污染防治和二次资源回收以及滑石矿产资源的综合利用提供了新的思路,对我国资源高效利用和环境净化具有一定的借鉴意义。

       

      Abstract: In order to achieve the efficient removal of heavy metal nickel ions in water and simultaneously recover nickel secondary resources, the natural talc mineral was modified by simple ball-milling process and directly applied for the purification of nickel-containing wastewater. The influence of activation intensity, talc dosage and initial concentration of nickel solution on the precipitation efficiency of nickel ions was systematically studied. The samples before and after reaction were tested by XRD, FTIR and SEM-EDS to clarify the mechanism of interaction between talc and nickel ions. The results demonstrated that the precipitation capacity of talc on heavy metals was significantly enhanced after ball-milling. Ball-milling of talc induced the collapse of crystal structure, with the dissolution of OH-/Mg2+ from the talc structure, facilitating the interaction between OH- and Ni2+ in solution to form amorphous Ni(OH)2 precipitation on talc surface, which worked as the main mechanism for nickel fixation by ball-milled talc. This achieved a maximum precipitation capacity of nickel ions up to 198 mg/g at the conditions of milling speed at 500 r/min and the initial Ni2+ concentration of 1 000 mg/L, which was 10 times that of the pristine talc. This study provided a novel concept for the heavy metal pollution prevention and recovery of secondary metal resource, as well as the comprehensive utilization of talc minerals, which can possibly be a reference for the efficient utilization of resources and environmental purification.

       

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