| Truck transport pavement is one of the key dust sources of open-pit coal mine.At present,most of the transport roads of open pit coal mines use water spraying to reduce dust,while water spraying to reduce dust in the northern cold regions of China will lead to serious potential safety hazards.How to solve the contradiction between dust suppression by watering and ice formation by watering on the truck transport road surface of the open pit coal mine in the cold area is a practical problem to be directly solved in this paper.In this paper,a chlorine free antifreeze and dust suppression agent has been developed and applied through road dust mechanism analysis,dust characteristic test,monomer material screening test,orthogonal test of chlorine free antifreeze and dust suppression agent formula,property performance test and on-site dust suppression effect verification test.The main research contents and conclusions are as follows:(1)Through the analysis of the force under the instantaneous lifting state of the dust on the surface of truck tires,combined with the influence of the induced airflow and shear airflow formed during truck transportation on the movement process of dust particles,and the influence of the concave and convex road surface on the dust production,the critical conditions for lifting the dust on the road surface of open pit coal mine transportation and the dust raising mechanism are clarified;According to the measurement and analysis of pavement dust,the pavement soil layer is weakly alkaline,and the main elements are Si,Fe,Al,and most of them are hydrophobic small particle dust.It is determined that the chlorine free antifreeze dust suppressant should have the functions of wetting,moisturizing,bonding and antifreeze.(2)The results of monomer material screening experiment show that the best monomer materials of dust suppressants are respectively sodium dodecylbenzene sulfonate,glycerol,polyacrylamide,and the mixture of ethylene glycol,potassium acetate and potassium formate in terms of wetting,moisturizing,bonding and antifreeze functions after the determination of such monomer material screening experiment indicators as penetration rate,surface tension,contact angle,evaporation resistance,viscosity and freezing point.(3)The optimum ratio of chlorine free antifreeze and dust suppression agent was determined as follows:sodium dodecyl benzene sulfonate 0.25%,glycerol 3%polyacrylamide 0.07%,ethylene glycol 29%,potassium acetate 4%and potassium formate 11%,and freezing point was-35.3℃by using the selected optimal monomer materials and designing four factor and three level orthogonal tests;The property and performance of the optimal dust suppressant showed that the p H of the dust suppressant was 8.53,which was weakly alkaline.The viscosity and permeability would be affected by temperature.The wettability of the dust was better than that of water,and the corrosivity was poor.The dust suppressant had good wind erosion resistance,evaporation resistance and harmless to plant growth.(4)In the field test,the best dilution ratio of dust suppressant at-25℃is 1:1,the spraying amount is 2L/m~2,the effective dust suppression duration of spraying dust suppressant is 7 days,and the effective dust suppression duration of spraying water is 35min;After comprehensive analysis of the detailed cost of spraying water and dust suppressant,it can be seen that spraying dust suppressant on the transport road surface of open pit coal mine every winter saves nearly2,102,600 yuan compared with spraying water for dust suppression,and the cost is reduced by39.5%.It is determined that the chlorine free antifreeze dust suppressant on the transport road surface of open pit coal mine in cold regions has good dust suppression effect and application value.There are 32 figures,28 tables and 85 references in this paper.This paper has 28 figures,24 tables and 89 references. |
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