content is generally more than 10%, even up to 90 %. Some gold mines , most of the production
in quartz veins , free silica content is generally above 60 %. Under this situation ,
according to the national emission standards , Crushing And Screening PlantVentilation and dust removal system effluent concentration should not exceed 100 mg/m 3 (free silica content of less than lO% of the mineral dust emissions allowable concentration of 150 mg/m 3 ) .
The concentration of dust in the air and dust is a measure of the dispersion of the important
factors to human hazards of dust . According to the Health specification , production dust
containing more than lO% free silica dust in the workshop maximum allowable working zone
concentration of 2 mg/m 3 , with lO% = less free silica dust , the maximum allowable
concentration of 10 mg/m 3. According to the information, the majority of alveolar deposition
of dust particles in the 0.2 to 2 microns in diameter . Thus , generally considered less than
5 microns of dust most harmful to humans .
So take certain removal equipment is very necessary work , it is not only related to the
health of staff, but also seriously affect the long-term development of enterprises.
(1)Material humidification humidification material is a very important measure dust , if the
production permits, as the ore humidification. Amount of water (W) can be calculated as : raw
material moisture content ,% ; final water content of the material ,% ( about 4-6 %) .
Methods commonly used materials humidification nozzle humidification.
(2)Equipment closed and ventilation ( mechanical removal ) is sealed dust production point
spread of a dust suppression measures necessary . Sometimes though a mechanical design system
for dust , but confined strictly to achieve desired results, of course, and not just confined