Study On Coal Resource Characteristics And Coal Preparation Technology Of Hetaoyu Coal Mine

Hetaoyu coal mine was located in the southeastern edge of Ordos Coal-accumulating Basin in Longdong area,including 2~#,5~#and 8~#mineable coal seams.2~#and 5~#coal seams are weakly caking coal with unstable distribution.8~#coal seam is non-caking coal with stable distribution which is main mineable coal seam.This paper is mainly focused on 2~#,5~#,8~#coal seams in Hetaoyu coal mine as the research object(with emphasis on 8~#coal seams).Based on clearly understanding the characteristics of coal resources in this area,it systematically studies the process of this coal mine and decides the best coal preparation process in order to realize clean,efficient utilization and reasonable development.According to coal quality variation of different coal seam,reasonable arrangement of coal preparation process contributes to improve separation accuracy,realize high efficient separation and significantly increase raw coal washing percentage.It also has important value in making large-scale coal preparation plant,high-efficient operation,process flow simpli-fication,operation automation,design standardization,layout modularization and profit maximization.After the study on coal quality characteristics of 2~#,5~#and 8~#coal seams,it finds out that the overall characteristics are low ash,medium and high volatile,low sulphur,medium phosphorus,high calorific value,non-caking or weakly caking,hard-to-separate and being in the Ⅱ metamorphic stage of bituminous coal.It can be used as power coals and chemical industry-used coal.Based on the study of sink-float characteristics and washability of 2~#,5~#and 8~#coal seams,it shows the dominant density is 1.30～1.40 kg/l.Ash content is less than 9.0%.Yield is high.So all of these facilitate to get low ash clean coal with ash less than 9.0%.The less dominant density is +2.0 kg/l with high ash.Lump coal contains more pure reject.Little middlings is in 1.6-2.0 kg/1 density which facilitates washing.The theoretical separation density of Hetaoyu coal mine is 1.8 kg/1,which is middle difficult-to-wash.But products with different ash have different composition.When theoretical separation density for middle ash coal is 1.8 kg/1,theoretical clean coal ash is 11.76%and theoretical clean coal yield is 75.57%.When theoretical separation density for high ash coal is 1.8 kg/1,theoretical clean coal ash is 12.96%and theoretical clean coal yield is 68.5%.After comprehensive analysis of coal preparation process,product structure and technology and economy conditions,it concludes that the reasonable coal preparation method and process is:-13 mm small coal with low ash and high calorific value is not necessary to be washed.The process for +13 mm coal is that 200～13 mm coal is washed by HM bath.13～3 mm small clean coal is recovered by centrifuge.3～0.5 mm coarse slime is recovered by slime centrifuge.-0.15 mm slime is treated by filter press.For high ash coal,TDS intelligent dry selection system is used.Meanwhile,raw coal quality variation is considered,it reserves feed channels and site for-13 mm small coal.