煤样破碎、缩分和干燥问题分析 ,

分析了煤样破碎、缩分和干燥的相关问题,并给出了具体的处理方法。对于破碎后的煤样粒度要求,建议某一粒级破碎后的煤样以全部小于该粒度为宜;针对目前2种破碎煤样水分偏倚试验方法存在的问题,提出了新的水分偏倚试验方法。指出缩分后总样质量取决于煤样粒度、煤样品质不均匀性及所要求的制样精密度,分析了总样质量与各影响因素之间的变化关系;阐述了二分器缩分法、九点取样法、堆锥四分法、棋盘法、机械缩分应用中需要注意的问题。最后分析了干燥过程中,采用两步法测定全水分时第一步干燥温度不能高于40℃的原因,并归纳了空气干燥应用原则。 Provide specific methods for resolving the problems related to coal samples reduction,division and drying.For the size fraction of crushed coal,all coal samples should be less than the spiculated size.In view of the existing problems of the current two test methods for moisture bias caused by coal sample reduction,provide a new moisture bias test method and test procedure.The coal sample size,variability of quality and required preparation precision are determinants of the gross sample mass.Analyse the relationship between the gross sample mass and its influencing factors.Elaborate issues,to which need to be paid attention during the application of riffle,nine-dot,quarter-cone,flattened-heap methods and mechanical division.When adopting two-step method to test the total moisture,explain the reasons why the temperature of the first drying step need to be below 40 ℃.Introduce the application principles of air drying method