What is Wisdom?
When minerals are extracted from the mountain, they need to be broken into smaller pieces. Ore should be smaller for several reasons:
Easy to transport.
Easier to buy and sell in the market.
Valuable minerals can be extracted more easily.
As mentioned, the whole process of crushing is due to the convenience of continuing to use ores. For this purpose, external force is used to shrink the ore. In fact, to answer the question of what is shrinking, it should be said: introducing an external force to the object, in order to reduce the initial dimensions, is called shrinking.
The most important goal in crushing is to release valuable minerals from the ores. For this purpose, the crushing operation must be done in such a way that the minerals are freed from the waste materials. In mines, more than 70% of the cost of mining is related to the crushing process, and the use of today's technology and technologies combined with scientific study will yield better results.
Crushing in a mine is done in two stages. In the first stage, stone crushers are placed in the line, which is called crushing, and in the second stage, there is a stone mill, where the softening or grinding operation is performed.
💠 Types of Mineral Crushed Methods 💠
The crushing operation is carried out in two stages, crushing and grinding. Mineral crushing operations are carried out in dry form in cement factories, and grinding operations are carried out in wet and dry form. No matter which device is chosen, the crushing methods are the same in all operations, both dry and wet. In general, the grinding method in all industries and for all materials is divided into three main forms.
▪️ Wear ▪️ Cleavage Crushing These three methods generally include the process of converting large minerals into small components. "wear" The first step in the operation is cutting. This mechanism is called Abrasion or Attrition. In this mechanism, due to the contact of two objects at the same point, grinding action is formed. The result of this point pressure is two products. ▪️ Fine grain ▪️ Coarse-grained
The wear mechanism is used in the industry to produce micronized powder. In the wear mechanism, we decrease or increase the amount of wear by changing the speed or number of rotations of the axle. The type of Asia is effective in the amount of abrasion.
Abrasion is mostly used for crushing brittle materials such as limestone and coal. The amount of energy in the abrasion process is the lowest amount of energy in grinding methods.
" failed " The second mechanism is breaking or cutting, which is done in two forms: cleavage and chipping. In the case of cleavage, the surface of the body is not symmetrical and discontinuous. In this case, the force enters the asymmetric surface and causes the object to break. In the state of chipping, the surface of the stone has asymmetric edges. For a better visualization, consider a star that has triangular edges and the base surface of these triangles is connected to a pentagon. In the chipping mode, the force enters the edges and separates from the central part, this mode is also called lip filling. In the breakdown mechanism of the Asian product, most coarse-grained materials are formed and less fine-grained ones are formed. " hit or push " This mechanism is the last crushing mechanism and it is called impact or Shatter. In this case, the amount of force applied to the stone is greater than the resistance of the stone. Another reason that causes impact or pressure on the stone is the high speed of loading in the mill. In the impact or pressure mechanism, we will see a wide range of coarse and fine grain products. Pressing operations are carried out in rod and ball mills more than usual. "Knock" Whether pounding is part of the crushing method or not depends on people's definition of crushing. The group that considers crushing to be synonymous with freeing valuable minerals does not consider pounding as part of the crushing method. But the group who consider the act of crushing as a part of crushing will also consider pounding as part of the method of crushing. In fact, knocking is the method and the first part of the crushing operation. In this method, very little energy is spent on crushing and less fine materials will be obtained. This method is used to break brittle and brittle materials.