Dust type:
1, free silica content (%)
2, respirable dust concentration (dose /m3)
3. Coal dust: ≤55.0
4. Rock dust: 5 ~102.5/10 ~ 301.0/30 ~ 500.5/≥ 500.2.
5. Cement dust: < 10 1.5. Effective dust control measures for coal dust (free silica content) are as follows:
1. Reforming technological process and manufacturing electronic equipment are the fundamental ways to avoid dust hazards. We should start with the design of production process, the free choice of electronic equipment, and the dust-producing machinery should have electronic equipment that meets the dust-proof requirements before leaving the factory. For example, closed air duct is used for transportation, negative pressure sand suction is used to avoid dust flying, silicon-free substances are used instead of timely sand blasting, and iron shot blasting is used instead of timely sand blasting.
Secondly, wet operation is an economical and effective measure to avoid dust flying. Any operation that can be manufactured by wet method can also be used. For example, mine wet drilling, road erosion, air purification, etc. , timely and wet crushing or spraying of ore, wet mixing of materials in glass and ceramics industry, wet sand modeling in foundry industry, wet sand cleaning out of the box, chemical sand cleaning, etc.
Three, airtight, suction, dust removal, for dust production jobs that can't use wet operation, the method of airtight suction and dust removal should be adopted. All the main equipment that can produce dust should be sealed as much as possible, and air should be absorbed by local machinery to keep a certain negative pressure in the closed electronic equipment to avoid dust escaping. The extracted dusty air can only be discharged after dust removal and purification to prevent air pollution.
Fourth, health care measures. To prevent and control the harm of dust to human health, we must first eliminate or reduce it from the source, which is the most obvious measure. The second is to reduce the dust concentration in the air. Finally, reduce the chance of dust being introduced into human body and reduce the harm of dust. Health care measures belong to the last link of prevention and control. Although it is an auxiliary measure, it still occupies the most important position. It also includes the following measures:
1: personal protection and personal hygiene. For the operation where the dust concentration cannot reach the allowable concentration standard for a period of time, it is the most important measure for the operator to wear a suitable dust mask. The dust mask should have high dust filtration rate and permeability, be light, and not affect workers' vision and operation. Carrying out physical exercise and paying attention to nutrition are of certain significance to enhancing physical fitness and resistance. In addition, we should also pay attention to personal hygiene habits, abide by dust-proof operation procedures, and strictly implement the system of not wearing dust masks at work.
2. Pre-employment and regular physical examination. It is necessary to carry out health examination for new workers engaged in dust operations, the main purpose of which is to find employment contraindications of dust operations as health information. The purpose of regular physical examination is to find out the harm of dust to health in the later stage and recall it as soon as possible when diseases unsuitable for dust operation are found.
3. Install an online dust concentration detector in various dust working environments. The main function of early warning is to prevent the dust concentration from exploding easily when it meets an open flame, and give a warning before the dust explosion and deal with it in time. The other is to prevent the dust concentration from being too high, and the human body inhales too much for a long time, leading to lung diseases.
legal ground
Regulation on classification and supervision of dust hazards
Article 4 All enterprises and institutions must conduct grading inspection and filing of productive dust operations every year according to the national standard GB58 17-86-86 "Classification of Hazard Degree of Productive Dust", and submit the grading results to the local labor administrative department.
Enterprises and institutions that do not have the ability of grading self-inspection shall ask the testing institutions of the local labor administrative department or the testing institutions recognized by the labor administrative department to carry out grading testing.