Every mining operation is followed by a beneficiation process aimed at delivering quality materials to the transformation industry. Mainly, in order to separate valuable minerals from gangue in mineral processing, the crushing and grinding of extracted ore are crucial operations for the following separation steps. Comminution is the most energy-consuming operation in mining, and the quality of the results is strictly related to the characteristic of the material under treatment, the type of equipment used in comminution, and the circuit design adopted. A preliminary study was performed in order to understand the crushing behavior under different comminution forces of a high-grade mixed Zn-Pb sulfide ore sample, collected in a Mississippi-Valley Type (MVT) deposit, and the distribution of the target minerals among the products of the process. Ore samples were examined and characterized through thin section observation and SEM analyses for the determination of grain size and texture features, while X-ray powder diffraction (XRPD) quantitative analyses were performed for the definition of target mineral concentrations of comminuted product samples. The selected crushing and grinding circuit comprised lab-scale equipment. For each stage of the process, products below the estimated free-grain size threshold were collected, and particle size analyses were carried out. Comminution products were divided into size distribution classes suitable for further separation operations, and XRPD analyses showed a mineral-grade distribution varying with the dimensions of the products. Characterization of the ore material after crushing and grinding force applications in terms of the distribution of target minerals among different-sized classes was achieved. The important trends highlighted should be considered for further investigation related to an efficient separation.

中文翻译：

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粉碎对矿物品位分布的影响：MVT铅锌矿床的案例

每次采矿作业后都会进行选矿过程，目的是向转型行业提供优质的材料。主要地，为了在矿物加工中从脉石中分离出有价值的矿物，提取矿石的粉碎和磨碎对于以下分离步骤是至关重​​要的操作。粉碎是采矿中最耗能的操作，结果的质量与所处理材料的特性，粉碎所用设备的类型以及采用的电路设计严格相关。为了了解密西西比河谷型（MVT）矿床中收集的高品位混合Zn-Pb硫化矿石样品在不同粉碎力下的破碎行为以及目标矿物在各矿物中的分布，进行了初步研究。产品的过程。通过薄片观察和SEM分析对矿石样品进行了检查和表征，以确定晶粒尺寸和织构特征，同时对X射线粉末衍射（XRPD）定量分析进行了分析，以确定了粉碎产品样品的目标矿物质浓度。选定的破碎和研磨回路包括实验室规模的设备。对于该过程的每个阶段，均收集低于估计的自由粒度阈值的产品，并进行粒度分析。粉碎产品分为适合进一步分离操作的粒度分布类别，XRPD分析表明，矿物级分布随产品尺寸而变化。根据目标矿物在不同尺寸类别中的分布，对粉碎和磨削力作用后的矿石材料进行了表征。应将突出显示的重要趋势与有效分离相关的进一步研究考虑在内。