same, i.e. to separate the minerals into two or more products with the values in the concentrates, the gangue in the tailings, and the “locked” particles in the middlings.
无论采用什么方法,矿物加工的目的都是一样的,就是把矿物分离为两种或两种以上的产品,使有用矿物进入精矿、脉石矿物进入尾矿、连生颗粒进入中矿。
2 Limitation of Mineral Processing 矿物加工的局限性
Such separations are, of course, never perfect, so that much of the middlings produced are, in fact, misplaced(混杂的) particles. This is often particularly serious when treating ultra-fine particles, where the efficiency of separation is usually low.
矿物分选不是完美的，大部分中矿实际上是混杂颗粒。尤其是处理超细颗粒时，这种情况更为严重，分选效率也比较低。 3 Recovery回收率
The recovery, in the case of the concentration of a metallic ore, is the percentage of the total metal contained in the ore that is recovered in the concentrate. 对于金属矿选矿来讲，回收率是指进入精矿中金属占矿石中金属总量的百分比。
4 The ratio of concentration 选矿比
The ratio of concentration is the ratio of the weight of the feed to the weight of the concentrates.
选矿比是指给矿（原矿）重量与精矿重量之比。（表示生产1吨精矿所需要处理的原矿数量） 5 Grade 品位
The grade, or assay, usually refers to the content of the marketable end product
in the material.
品位通常指物料中所含适销最终产品的含量（如金属含量，铁矿石中TFe的含量）。
6 Enrichment ratio
The enrichment ratio （富集比）is the ratio of the grade of the concentrate to the grade of the heads, and again is related to the efficiency of the process.
Review of the last lesson
The object of mineral processing
The object of mineral processing, regardless of the method used, is always the same, i.e. to separate the minerals into two or more products with the values in the concentrates, the gangue in the tailings, and the “locked” particles in the middlings. Recovery
The recovery, in the case of the concentration of a metallic ore, is the percentage of the total metal contained in the ore that is recovered in the concentrate. 4 The ratio of concentration
The ratio of concentration is the ratio of the weight of the feed to the weight of the concentrates. Grade
The grade, or assay, usually refers to the content of the marketable end product in the material. Enrichment ratio
The enrichment ratio is the ratio of the grade of the concentrate to the grade of the heads, and again is related to the efficiency of the process.
Unit2 Lesson1
Introduction 简介
The liberation of valuable minerals from the gangue minerals is achieved by comminution, in which the particle size of the ore is progressively reduced until the clean particles of mineral can be separated by some concentrating methods.
有用矿物与脉石矿物的解离是通过粉碎完成的,通过粉碎使矿石颗粒逐步减小至能够分离的纯净颗粒。
Crushing and Grinding 破碎与磨矿
Crushing is accomplished by compression of the ore against rigid surface, or by impact the surfaces in a rigidly constrained motion path.
破碎是靠刚性表面对矿石的压力或是在严格限定的运动轨道内，表面对矿石的冲击而实现的。
Grinding is accomplished by abrasion and impact of the ore by the free motion of unconnected media such as rods, balls, or pebbles.
磨矿是矿石被钢棒、钢球或砾石等离散介质的研磨和冲击作用而完成的。 Strain of a crystal lattice 晶格的变形
In the crystalline lattice of minerals, the inter-atomic bonds are effective only over small distances, and can be broken if extended by a tensile stress. 在矿物晶格中，原子间的键力仅在一个很小的距离内有效，能够被拉应力拉伸而断裂。
Stress concentration 应力集中
The distribution of stress depends upon the mechanical properties of the individual minerals, but more importantly, upon the presence of cracks or flaws
in the matrix, which act as sites for stress concentration. 应力分布取决于各种不同矿物的力学性质，但更重要地取决于矿石内部中裂隙和裂纹的存在，因为这些地方能够成为应力集中的部位。 Crack propagation 裂纹扩展
Materials fail by crack propagation when the energy released by relaxing the strain energy is greater than the energy of the new surface produced.
当释放的形变能大于新生表面能时，材料就能够通过裂纹扩展而破裂。 Modes of fracture 破裂模式
Breakage is achieved mainly by crushing, impact, and attrition. Therfore, there are three modes of fracture such as compressive, tensile, and shear fracture.
（矿石）破裂主要通过压碎、冲击和研磨作用而实现。因此，主要有压力破裂、拉力破裂和剪切破裂三种破裂模式。
Review of the last lesson
Function of comminution
The liberation of valuable minerals from the gangue minerals is achieved by comminution, in which the particle size of the ore is progressively reduced until the clean particles of mineral can be separated by some concentrating methods.
Crushing and Grinding
Crushing is accomplished by compression of the ore against rigid surface, or by impact the surfaces in a rigidly constrained motion path.
Grinding is accomplished by abrasion and impact of the ore by the free motion of unconnected media such as rods, balls, or pebbles. Strain of a crystal lattice