Dust is one of the main reasons that seriously restrict the efficient, safe and clean production of mine concentrator. Ore from the transport, transport, crushing, screening and into the production workshop and other processes can produce dust, so strengthen the production process improvement is the main method to control dust diffusion, fundamentally eliminate the harm of dust, and then achieve environmentally friendly production goals.
The cause analysis of dust can be divided into two types according to the way of dust generation and inducing factors:
First, in the process of processing bulk materials, the air fluidity is significantly increased, and then the fine granular materials are brought out to form dust (a dust);
Second, due to the operation of equipment in the production workshop, the indoor air mobility increases significantly, which causes the indoor dust to be raised again (secondary dust).
The primary dust is mainly distributed in the crushing workshop, and the causes of dust generation include:
① Dusting caused by shearing: the ore falls into the mine bin from a high height, and the fine powder appears shear under the action of air head-on resistance, and then floats in suspension. The greater the height of the material falling, the greater the speed of the fine powder, and the more obvious the dust is.
(2) Induced air dusting: When the material enters the mine bin along the entrance, the material has a certain speed during the falling process, which can drive the surrounding air to move with the material, and the sudden acceleration of the flow of air can drive some fine materials to suspend and then form dust.
(3) Dusting caused by equipment movement: in the material screening process, the screening equipment is in a high-frequency motion, which can cause the mineral powder in the ore to mix with the air and form dust. In addition, other equipment such as fans, motors, etc., can cause dust.
(4) Dusting caused by loading materials: the dust caused by squeezing out the material in the process of loading the mine bin is diffused outward from the charging port.
Dust control method of crushing and screening Dust control method of crushing and screening in mining processing plant mainly includes:
The first is to reduce the dust content in the selection plant as much as possible, so that the indoor dust content meets the basic requirements of the relevant national standards;
The second is to ensure that the exhaust dust concentration meets the national standard exhaust concentration requirements.
01 Sealed air extraction dust proof method
The dust in the mine sorting plant mainly comes from the workshop dealing with bulk ore materials, and its crushing, screening and transportation equipment are the sources of dust. Therefore, the closed air extraction method can be used to control and eliminate dust in the workshop, the reasons include: first, it can effectively control the outward diffusion of dust, and the second is to provide basic conditions for air extraction and dust removal.
(1) The sealing of the equipment that generates dust during the implementation of closed air extraction and dust prevention is crucial, and it is the basis for cutting off the rapid diffusion of a single dust.
(2) The smaller the humidity of the material, the greater the amount of dust generated in the crushing process. In order to improve the effect of air extraction and dust prevention, it is necessary to seal the holes of the inlet and outlet of the crusher, and set the exhaust hood in the inlet chute or the feeder to effectively improve the dust removal effect. (3) The material moves along the screen surface during the screening process, which can make the fine material and sinking air mix together to form dust, so the equipment can be made into an integral closed equipment, that is, the vibrating screen is closed, and the air exhaust cover is set at the discharge port of the screen surface, which can effectively eliminate the dust in the vibrating screen.
The core technology of closed dust removal is to lay a closed dust cover in the main dust production location, effectively control the dust source, and then through the power of the fan in the air extraction equipment, the dust is sucked into the dust cover, and after the dust collector treatment, it is discharged from the corresponding pipeline. Therefore, the dust collector is the main component of the process, and the selection should consider the following points:
(1) The nature of the gas to be removed must be comprehensively considered, including the humidity, temperature, dust concentration, corrosion, etc.;
(2) The properties of dust should be considered comprehensively, such as dust composition, particle size, corrosion, viscosity, explosive, specific gravity, hydrophilic, heavy metal content, etc.
③ It is necessary to consider the indicators of air quality requirements after evolution, such as dust content in gases.
02 Wet dust prevention method
Wet dust control is the most commonly used dust removal method, which increases the humidity of ore materials by spraying water in the process of ore material transportation, crushing and screening, indirectly increasing the humidity, specific gravity and viscosity of fine materials, so that fine materials are not easy to mix with air to generate dust; Or spray the generated dust at the location of the dust point, so that the dust particles in the air will sink due to the increase in humidity, so as to achieve the purpose of dust removal.
Compared with spray dust removal, spray dust removal (ultrasonic atomization dust removal) is a more simple and economic way, and the effect is good, mainly composed of two parts: one is the spray system (atomizer, electric ball valve, water supply device and pipeline composition), the other is the electronic control system.
In order to improve the quality and effect of spray dust removal, the spray system should pay attention to the following points:
① The water mist used for dust removal must meet the basic needs of dust removal to the greatest extent, and keep the surface of the transport belt and other surfaces moist as far as possible, that is, to ensure that the water mist will seal the dust at the blanking port as much as possible.
② Should pay attention to the amount of spray water, this is because the water content in the ore increases more, which has a greater impact on the screening effect, therefore, the water in the water mist should be controlled within the range of the ore water content increased by 4%, which can effectively prevent the blanking pipe plugging problem.
③ The spray system should be based on automatic equipment, without manual control operation.
There are many sources of dust in mine, so the organic combination of closed air extraction and spray dust removal can be adopted. In addition, dust removal treatment needs to save water resources, power resources and so on, that is, under the same dust removal effect, as far as possible to save the cost of dust removal.
Post time: Oct-25-2024