深地破碎浸矿环境下溶液渗透机制及调控

In situ crushing leaching technology can effectively solve the "three highs" problems that the deep mineral resources exploitation faces, well the mechanism of solution infiltration in complex deep-leaching environment is not yet clear, restricting the increase of leaching efficiency and rate. In order to achieve uniform distribution of the solution penetration under deep-leaching conditions, the law of solution penetration in stope is studied in this project. Firstly, an environment experimental device is development to simulate the deep-leaching environment, and the stope scale solution distribution model is constructed based on spatial distribution characteristics of leaching blind zone and infiltration zone detected by nondestructive detection means. Secondly, carry out quantification of flow field between ores in deep-leaching environment to analyze flow velocity, vorticity, boundary distribution, then the law of rapid flow between ores is revealed. Thirdly, study the evolution characteristics of permeation rates in a single ore, clarify the law of slow infiltration inside the ore, thus, the solution flow model, coupled flow model for free-flow and slow-penetrating, in deep ground was constructed using dual medium theory. Finally, based on the flow model and the structural model, the occurrence and development of the dominant flow and the sidewall flow are studied using numerical simulation methods, then the distribution mechanism of the seepage field is clarified. By investigating the influence of temperature, spray intensity and concentration on the distribution of solution, a control prototype for uniform distribution of seepage field is established, which provides a theoretical basis for improving the seepage effect of the crushed leaching in the deep earth.

原地破碎浸出能够有效解决深地矿产资源开采面临的“三高”问题，但深地复杂环境下的溶液渗透机制尚未明确，制约矿石浸出率和浸出速率的提高。本项目以实现深地破碎浸出溶液均匀渗透为目标，开展采场内溶液渗透规律的研究。首先，研制一套模拟深地采场浸出环境的实验装置，基于无损探测手段探究浸出盲区和渗透区空间分布特征，构建采场尺度溶液分布模型；其次，进行矿石间流场的的量化表征，分析流速、涡量、边界分布特征，揭示深地环境下矿石间溶液快速流动规律；再次，研究溶液浸润单矿石的渗透速率演化特征，阐明矿石内部溶液缓慢渗透规律，并基于双重介质理论构建深地环境下耦合自由流和缓慢渗透的流动模型。最后，以流动模型和结构模型为基础，基于数值模拟研究优势流与边壁流的发生发展规律，阐明渗流场分布机制，通过探讨温度、喷淋强度、浓度等因素对溶液均匀分布的影响，建立渗流场均匀分布的调控原型，为改善深地浸出渗透效果奠定理论基础。

采场浸出能够有效解决深地金属矿产资源开采所面临的“三高一扰动”的突出问题，然而深地环境下采场浸出过程中溶液渗透差，渗透机制尚未明确，限制了采场浸出的应用。本项目以实现深地破碎浸出溶液多尺度渗透机制为目标，开展采场内溶液多尺度渗透规律的研究。首先，研制了一套模拟深地采场浸出环境的实验装置，探究溶液宏观渗透扩展特征，溶液扩展路径以竖向为主水平为辅，温度和喷淋强度升高促进溶液的渗透扩展，60°倾角采场下盘优势流更显著。其次，基于PIV技术进行矿石间流场的无损伤探测，并进行可视化与量化表征，界面微渗透作用下矿石流速和涡量分布被彻底改变，温度和喷淋强度的升高促进了矿石间溶液的流动。再次，基于MRI技术研究矿石内溶液微渗透特征，液体的扩展高度与时间为速率逐渐降低的幂函数增长关系，孔隙率增大对微渗透的影响远大于温度的升高。然后，基于工业CT开展了溶浸采场模型内孔隙特征探测，分析孔隙量化特征与采场渗透关系，孔隙率和喉道尺寸是影响采场渗透率的关键因素。最后，构建了温度场-矿石间流场-矿石内流场耦合流动模型，借助数值模拟采场内溶液分布及优势流的发生规律，探讨温度、喷淋强度、采场倾角等因素对采场内部溶液分布的影响规律。本项目的研究成果为改善深地浸出渗透效果奠定理论基础。