Gold is a non-ferrous metal ores, which are mostly metal ore dust mixed dust , free silica 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 10% 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 actors to human hazards of dust . According to the Health specification , production dust containing more than 10% free silica dust in the workshop maximum allowable working zone concentration of 2 mg/m 3 , with 10% = 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 ealth 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 %) . 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 onfined to a certain negative pressure inside the sealed cover , they can not achieve good results. Branch of the Ministry of sealed airtight , sealed and large overall volume closed (or closed -chamber ) .
Sealed cover should be set smart , tight, and ease of operation in order to maintain its vitality. Have sufficient volume of the hood to cushion the airflow disturbance formed positive . Dust sealed cover wind section should cover the mouth too large, otherwise will bring a lot of dust removal system and increase the burden of cleaning equipment . (3)the use of high-tech Gold Separation Equipment, the device comes ith a bag filter has a high collection efficiency , generally in the 95 to 99 percent , Shanghai Zenith Mining and Construction Machinery Co. Ltd. designed the low-pressure pulse bag filter this air pressure is reduced to solve the dust problems can be at 1. 96105 ??” 2. 94105 pulse cleaning when Pa . With the development of science and technology, computer technology is gradually applied to gold mineral processing , computer room air conditioning and their corresponding precision instruments should be designed according to process requirements. Ventilation drying plant re direct fire and smoke kiln indirectly heated drying .
Due to the large amount of dust in the flue gas extraction(about 1 5 g/m 3 or more) , and therefore , two-stage dust collection are : a first stage a dry cyclone(shall be insulated) , the second stage in general wet dust collector(if the bag can withstand high temperatures , can also be used baghouse). Wet scrubber should be anti-corrosion treatment , due to the flue gas temperature is relatively high, the current use of sugar of lead water film dust . Some of sulfur concentrate itself , which easily handled .