Analysis of the causes and countermeasures of dust pollution in mine production

Dust pollution control measures

From the perspective of the causes of dust sources in the mining area, each process will produce dust pollution, but the intensity of the production is different. To distinguish the primary and secondary, grasp the key points, and carry out comprehensive treatment of these dust-producing parts, dust pollution can be effectively controlled.

1. Closure of dust source

Take sealing measures to strictly close the dust producing parts and dust producing equipment, so that the dust is enclosed in a certain space. For example, the rock drilling platform of the cone drill is provided with a dust collecting cover at the hole, so that all the dust producing parts are sealed and dust is controlled locally.

2 Wet operation

Increase the humidity of mineral rock and working face, road, prevent dust flying, reduce the amount of dust in the air. This is the main way to prevent dust in the dry season.

3 Dust proof during perforation

Cone drill perforation. Water and gas form a feng shui mixture along the center of the drill pipe to the bottom of the hole. During the drilling process and the slag discharge process, the dust is wetted to form wet powder or mud, and then discharged to the sealing cover.

4. Dust proof in blasting operation

Water can be sprayed into the pre-explosion area before blasting. Water can not only wet the surface of ore and dust, but also penetrate into the ore body through cracks, which plays a good dust-proof effect.

5 Shovel loading operation dust

✪ pre-wet the detonation reactor. Loaded with hard rock and washed with water gun; When excavating soft and dusty soil, sprinklers are used to spray it.

✪ Spray water during loading. Water tank and fan are set on the shovel to form feng shui mixed spray, and make it move with the shovel loading and unloading operation, and spray directly to the dust source to achieve good dust removal effect.

7 Transport road dust

✪ sprinkler. Road traffic dust is the biggest source of dust pollution in mining area, and doing a good job of road dust prevention is the most important means of dust pollution control. In the dry season, the road material of appropriate specifications is laid on the main transportation lines, and the water is sprayed on the road surface regularly with sprinklers, and the intermittent water spraying or mist spraying is implemented, so that the dust qualification rate of the trunk line can meet the safety technical requirements.

✪ Pressurized pipe spraying. With the increasing length of fixed pit lines in depressed mining areas, dust suppression work in mining areas becomes more and more difficult. Especially in summer, it is difficult to meet the needs of safe dust suppression work by spraying dust suppression with electric powered wheel sprinkler. Facing this situation, water spraying with pipelines is adopted in some conditional fixed pit lines in mining areas to relieve the pressure of electric wheel sprinkling water and improve the dust suppression effect.

8 Crushing and screening dust treatment

Set up spray dust removal device. In the crushing operation, the moisture content of the material surface is an important factor to reduce the dust escape. The spray dust removal device set in each feed port of the crusher can play a powerful role in dust suppression. If water spraying is used for dust removal alone, the water volume is too large, and the inlet is blocked. The water amount is too small, and the dust suppression effect is not achieved, and the use of chemical wetting agents can maintain a certain moisture content on the surface of the material and reduce the water consumption (the water consumption ratio before and after is 4:1). The chemical wetting agent is mixed with water at a ratio of 1:20,000, and the mixed liquid is fully atomized through the spray nozzle with high pressure gas, and evenly sprayed on the material, so that the material is moistened and the surface humidity is increased.

9 Belt transport dust control

Reasonable setting of spray dust removal device at each transfer point and using transfer point sealing spray to suppress dust can achieve effective effect of reducing the dust concentration at the post. The head and tail of each transfer point are sealed for 3 ~ 5m, and the spray nozzle is uniformly arranged in the cover. High-pressure gas is used to atomize water through the spray nozzle into 30 ~ 60um fog drops, and the dust in the air in the cover is collected by condensation and collision. In order to avoid slipping between the belt and pulley, chemical wetting agents are added to the water to reduce water consumption. The use of wet operation and wet dust removal in the crushing system can reduce the dust concentration of the post by 70% to 80%, and the exhaust dust concentration can be reduced to less than 100mg/m³.

10 Second dust treatment

Spray water or sodium chloride solution to dust secondary flying points (such as working faces, refurbished slopes, waste dumps, etc.), or spray covering agent on the surface of dusty materials. There is a bonding force between the covering agent and the waste rock, and they permeate and diffuse each other. Under the action of chemical action and physical adsorption, a thin layer of hard shell is formed on the surface of waste rock to prevent dust from wind and sun.