细粒级铜尾矿基新型人工合成防渗材料研究

Research on Ultra-Fine Copper Tailings Based New Artificial Anti-Seepage Material

摘要: 为拓展铜尾矿的综合利用途径，本研究采用膨润土和黄原胶掺入细粒级铜尾矿制备新型人工合成防渗材料，并探究该材料应用于一般工业固废贮存场或填埋场防渗的可行性。由铜尾矿物理性质分析可知，铜尾矿体积平均粒径d_p为0.022 mm，其中尾矿粒径−0.019 mm的颗粒质量占总质量的18.45%。且铜尾矿微观结构呈疏松多孔状，容易让水分子进入并流动。由不同膨润土和黄原胶掺比的单因素研究可知，当膨润土掺比量达10%时，混合样品渗透系数最低降至8.2E-7 cm/s。当黄原胶掺比量达1%时，混合样品渗透系数达7.4E-6 cm/s。随后为减少膨润土和黄原胶的掺比，使用BBD设计优化铜尾矿–膨润土的配方。由实验结果可知，当膨润土掺量为5.43%，黄原胶掺量为0.48%时，铜尾矿–膨润土材料的渗透系数可从5.5E-4降低至国标要求1E-05 cm/s，可满足一般工业固废I类场防渗要求。研究结果表明该材料具备应用作一般工业固废贮存场及填埋场防渗材料的可行性。

Abstract: In order to expand the comprehensive utilization of copper tailings, this study used bentonite and xanthan gum to prepare a new synthetic anti-seepage material with fine grade copper tailings, and explored the feasibility of applying this material to general industrial solid waste storage field or landfill site. According to the physical property analysis of copper tailings, the average particle size d_p of copper tailings is 0.022 mm, of which the particle mass of tailings with a particle size of −0.019 mm accounts for 18.45% of the total mass. The microstructure of copper tailings is loose and porous, which is easy for water molecules to enter and flow. According to the single factor study of different bentonite and xanthan mixing ratio, when the bentonite mixing ratio reaches 10%, the permeability coefficient of the mixed material decreases to the lowest 8.2E-7 cm/s. When the content of xanthan gum reaches 1%, the permeability coefficient of the mixed material is 7.4E-6 cm/s. In order to reduce the mixing ratio of bentonite and xanthan gum, BBD design was used to optimize the formula of copper tailings and bentonite. According to the experimental results, when the bentonite content is 5.43% and xanthan gum content is 0.48%, the permeability coefficient of copper tailings and bentonite material can be reduced from 5.5E-4 to 1E-05 cm/s required by the national standard, which can meet the seepage prevention requirements of general industrial solid waste Class I field. The results show that the material is feasible to be used as impermeable material in general industrial solid waste storage and landfill.