风化壳淋积型稀土矿原地浸出传质过程强化

Weathered crust elution-deposited rare earth ore as the main mineral resource rich in middle and heavy rare earth is usually recovered by the in-situ leaching in the world. However, the economic benefit of rare earth mine is always damaged by a series of challenges such as the contaminated water source by leachate seepage, the low leaching rate of rare earth and the landslides due to a lack of basic researches on the rare earth leaching process. Therefore, the mineral species in the ore body, the rare earth distribution characteristics and the migration and enrichment of rare earth are investigated to reveal the migration forms of rare earth in clay minerals, build a migration and enrichment model of middle and heavy rare earth in crust system, and further innovatively establish the col enrichment theory of middle and heavy rare earths. The in-situ seepage mechanic, leaching kinetics, mass transfer process intensification, seepage and exchange rare earth of leaching agent in ore body, expansive mechanism of clay minerals in leaching process are also discussed to find the distribution and evolvement rules of pore water pressure, permeability coefficient, shearing strength and concentration gradient of the leaching agent. A seepage- mass transfer-reaction model will be deduced to monitor and control the in-situ leaching process effectively. All the above researches will built a complete set of technical theories for the in-situ leaching process of weathered crust elution-deposited rare earth ore to improve the rare earth recovery and eliminate the geological disasters such as landslide.

风化壳淋积型稀土矿是全球中重稀土的主要来源，其开采主要采用原地浸出工艺，由于缺乏稀土矿浸出过程的基础研究，导致浸出液渗流污染水源、稀土浸出率低和山体滑坡等难题，严重影响稀土矿山的经济效益。为此，从风化壳淋积型稀土矿工艺矿物学入手，开展矿体中矿物种类、稀土分布特征、稀土的迁移富集，揭示稀土在黏土矿物中的赋存状态，建立中重稀土在风化体系矿体中迁移富集模型，创新性地构建中重稀土的山坳富集理论。开展原地浸出渗流力学、浸出动力学、传质过程强化、浸取剂溶液在矿体中渗流及交换稀土的机制、浸取过程黏土矿物膨胀机理等研究，探索原地浸出过程中孔隙水压力、渗透系数、抗剪强度和浸取剂浓度梯度等分布特征及演变规律，构建原地浸出体系渗流-传质-反应耦合模型，有效地对矿体原地浸出过程进行监测和控制，形成一整套原地浸出风化壳淋积型稀土矿的技术原型，为提高稀土回收率和消除山体滑坡的地质灾害提供理论依据和技术支撑。

风化壳淋积型稀土矿是全球中重稀土的主要来源，其开采主要采用原地浸出工艺，由于缺.乏稀土矿浸出过程的基础研究，导致浸出液渗流污染水源、稀土浸出率低和山体滑坡等难题，.严重影响稀土矿山的经济效益。本项目围绕风化壳淋积型稀土矿原地浸出传质过程强化展开了一系列的研究，主要研究内容如下：（1）从微观角度对稀土浸取过程中的溶剂化行为进行了理论研究，进一步验证了风化壳淋积型稀土矿稀土配分的分馏理论；（2）研究了风化壳淋积型稀土矿孔隙结构特征，建立了矿样孔隙结构三维数值模型，分析了稀土矿孔隙结构演化规律；（3）研究了孔隙比对风化壳淋积型稀土矿抗剪强度的影响特征，分析了浸矿作用下稀土矿力学弱化因素，探讨了浸矿时间对稀土矿力学弱化影响规律；（4）揭示了孔隙比、细颗粒含量等对稀土矿渗透特性的影响规律，建立了风化壳淋积型稀土矿抗剪强度指标与渗透性的数学模型；（5）筛选风化壳淋积型稀土矿高效抑膨浸取剂，探索原地浸出浸取过程动力学和传质机理；（6）研究风化壳淋积型稀土矿中黏土矿物中稀土离子与浸矿剂溶液中交换阳离子及配位阴离子的竞争吸附与脱附机制；（7）完成了Zn-Al类水滑石吸附回收模拟稀土矿山尾水中低浓度稀土研究。上述研究内容形成一整套原地浸出风化壳淋积型稀土矿的技术原型，为提高稀土回收率和消除山体滑坡的地质灾害提供理论依据和技术支撑。