In the processing of mechanical sand and gravel, it is very important to master the properties of the source rock, such as the physical and mechanical properties of the rock, mineral composition, chemical composition and the processing performance index of the rock. It is mainly understood that the crushing work index and the abrasion index are used as important reference indicators for the selection of preliminary equipment, subsequent production and processing, and the maintenance of sand and gravel equipment.In simple terms, it is the shatterability and abrasive properties in the processing properties of rocks.
1. The shatterability of rocks
The fragmentation work index WI is usually used to characterize the shatterability of rocks. It is closely related to the chemical composition of rocks, the development of joints (which can also be understood as cracks in rocks), and the crystallization state.For example, hard quartzite is difficult to break, and limestone is much easier.The shatterability of the rock affects the particle size of the discharge of the crushing equipment, which in turn affects the selection of the equipment.Generally, according to the range of crushing work index, the rock's shatterability is graded as: 1422, which is very difficult to break.There are more medium-shatterable limestone used in daily civil buildings. The common hard rocks in hydropower projects are deep-formed igneous rocks (such as granite, syenite, diorite) and ejected igneous rocks (such as basalt and diabase).A typical hard rock index common in sand and gravel processing.
2. The abrasive nature of the rock
The abrasive index AI and SiO2 content are usually used to measure the abrasive properties of rocks. It is related to the hard mineral content of rocks (SiO2, orthoclase, etc.), crystal structure, raw material size, rock compressive strength and other factors.The abrasive properties of rocks mainly affect the life and wear costs of wear-resistant parts during the operation of the equipment, so the abrasive properties of rocks are an important parameter for determining the selection of equipment.According to the rock abrasion index, the rock abrasion is graded as: 0.40.8, which is more abrasive.
