非离子型表面活性剂对风化壳淋积型稀土矿浸出过程的影响

Effect of Nonionic Surfactants on Leaching of Weathered Crust Drenched Rare Earth Minerals

为了缓解风化壳淋积型稀土矿浸取过程存在的浸取周期长、浸出剂用量大和稀土拖尾等问题,以非离子型表面活性剂为助浸剂,氯化镁为浸出剂,对稀土浸出过程进行研究,研究复配浸出剂溶液性质,分析浸矿前后矿物粒径分布,探讨表面活性剂的促渗机理。研究结果显示,加入表面活性剂后,稀土浸出率提高,渗透速度加快,溶液的表面张力和接触角均减小,黏度增大,矿物颗粒的中值粒径明显减小,矿物表面Zeta电位增大,其中加入吐温40后稀土浸出率提高至86.38%,表面张力减小19.00%,接触角减小53.19%,溶液黏度减小4.29%,溶液性质变化最大。加入表面活性剂后可使溶液更容易润湿矿物,进入孔隙的阻力变小,扩散层厚度减小,黏土矿物的膨胀受到抑制,使得溶液浸出稀土的效果更好,其中吐温40对溶液浸出稀土的渗流效果影响最大,助渗效果最好。

Address to long leaching cycle,high leaching agent dosage,and rare earth tailing in the leaching process of weathered crust drenching rare earth ore,the leaching process of rare earth was investigated by using non-ionic surfactant as leaching aid and magnesium chloride as leaching agent.The properties of compound leaching agent solution was studied,the particle size distribution of minerals before and after leaching was analyzed,and the mechanism of surfactant to promote percolation was explored.The results show that the addition of surfactant increases the leaching rate of rare earths,accelerates the permeation rate,reduces the surface tension and contact angle of the solution,increases the viscosity,significantly reduces the median particle size of the mineral particles,and increases the Zeta potential of the mineral surface.The addition of Tween 40 improves the leaching rate of rare earths to 86.38%,reduces the surface tension by 19.00%,reduces the contact angle by 53.19%,and reduces the solution viscosity by 4.29%,which the solution properties changes the most.The results show that the addition of surfactant can make the solution wet the minerals more easily,the resistance to enter the pore space becomes smaller,the thickness of the diffusion layer is reduced,and the swelling of clay minerals is inhibited,which makes the solution leaching rare earths better,among which Tween 40 has the greatest effect on the solution leaching rare earths percolation effect and the best percolation aid.