中厚倾斜矿体无底柱分段崩落法导流放矿机理研究

Serious problems such as high ore loss rate and high dilution rate arise during the production process of sublevel caving method for dipping middle thickness ore body as caved ore directly contacts with caved rock and flow mechanism of loose ore and rock is complicated. And it causes resource waste and environmental pollution. Therefore, research of ore drawing theory has important meaning to improve the economic benefit of mine and to realize greeen mining. This study aims to reduce ore loss and dilution in the process of sublevel caving mining.To achieve diversion drawing, the traditional form of direct contact between ore and rock is reformed and diversion structure is set in the contact interface of caved ore and waste rock. The movement law of loose ore and rock of diversion drawing was established by using stochastic medium theory. Moreover, to reduce ore loss and dilution, relationship between structure form of diversion drawing and the velocity field of loose body was analysed and methods such as controlling flow speed and flow direction of caved ore and rock were projected. On the basis of diversion drawing experiments, prediction and controlling methods of ore loss and dilution was proposed and its technical parameter design method was built. The research will help to reveal the mechanism of ore loss and ore dilution of diversion drawing and provide a scientific basis for reducing ore loss and ore dilution.

中厚倾斜矿体采用无底柱分段崩落法开采过程中存在严重的矿石损失与贫化问题，造成资源浪费和环境污染。导致损失贫化大的主因是矿岩直接接触以及矿岩流动机理复杂。因此，研究覆岩下放矿理论，对提高矿山经济效益和实现绿色开采具有重要的意义。本课题旨在降低无底柱分段崩落法开采过程中的矿石损失贫化。采用导流结构将覆岩和崩落矿石隔离开来，改革传统的矿岩界面直接接触形式，实现导流放矿。利用随机介质理论，建立导流放矿松散矿岩移动规律基本方程；分析导流结构形式与松散矿岩速度场之间的联系，通过控制松散矿岩的流动速度和方向，达到降低矿石损失贫化的目的。在导流放矿实验基础上，提出矿石损失贫化的预测与控制方法以及导流放矿技术参数设计方法。本项目的研究将揭示导流放矿过程中的矿石损失贫化机理，为降低采矿损失和贫化提供科学依据。

无底柱分段崩落法开采中厚倾斜矿体时，由于矿岩直接接触、矿岩流动机理复杂以及矿岩接触界面难以控制等原因，导致矿石损失贫化较严重。本项目以导流放矿技术为核心，采用物理模拟实验、理论分析及数值模拟相结合的方法，对松散矿岩流动规律、导流放矿损失贫化机理以及导流放矿结构稳定性等进行研究，取得了以下创新性成果：.(1) 弄清了斜壁放矿时散体流轴的主要特征。上部流轴与上盘边壁近似平行，下部流轴与放矿口中轴线重合，两者流轴长度均随矿体倾角和矿体厚度的改变而变化。提出根据流轴分界点将斜壁放矿散体流动区域简化的新方法。.(2) 弄清了斜壁放矿时放出体的主要特征。无影响区内，放出体形态不受上盘倾斜边壁的影响，其形态为一截头的近似椭圆。受斜壁控制区域内，放出体形态发生变异，放出体形态随放矿高度、矿体倾角和矿体厚度的变化而改变。.(3) 以随机介质理论为基础，建立了中厚倾斜矿体散体移动规律基本方程，主要包括颗粒移动速度方程、移动迹线方程和放出体方程。并对理论方程的合理性进行了验证。.(4) 提出了新型导流放矿技术，导流放矿结构改变了矿岩的接触形式和散体的移动路径，有效降低了开采中的矿石损失贫化。与常规放矿实验相比，新型导流放矿技术矿石回收率提高了4.37~19.26%，贫化率降低了3.12~25.52%。.(5) 阐明了导流放矿损失贫化机理。分析了新型导流放矿过程中贫化率与回收率的变化规律。分析了分段高度、矿体厚度和矿体倾角对矿石回收率、贫化率、回贫差等的影响。建立了矿石回收率的数学模型。.(6) 分析了不同导流放矿结构形式、矿岩力学特性、矿体产状等条件下导流放矿结构的稳固性。提出了综合考虑导流结构稳定性和矿石回收效果的导流放矿技术参数设计方法。本项目提出的新型导流放矿技术可为无底柱分段崩落法矿山降低损失贫化提供理论依据与实际指导。