为确定水洗脱除准东煤中水溶性钠的最佳工艺条件,选择五彩湾煤、天池能源煤、乌东煤3种准东煤,通过逐级萃取分离法对其中钠的赋存形态和质量分数进行研究,并以五彩湾煤为例采用正交实验和极差分析方法,研究水洗温度、脱除时间、煤粉粒径、搅拌转速等对水溶性钠脱除的影响。结果表明:3种煤总钠质量分数分别为2.329 5,2.235 9,0.598 0mg/g,煤种钠主要以水溶性钠形式存在;各因素对水溶性钠脱除影响的强弱顺序为水洗温度〉脱除时间〉搅拌转速〉煤粉粒径;在适当的水洗温度下延长脱除时间、加快搅拌转速、减小煤粉粒径,水溶性钠脱除效果明显提高;实验确定的最佳脱除水溶性钠工况条件为水洗温度70℃,脱除时间24h,搅拌转速200r/min,煤粉粒径在38.5~54.0μm之间。
To ascertain the optimal process condition for removing water solubility sodium in Zhundong coal,three kinds of Zhundong coals,WCW,TCNY and WD,were selected as the samples to investigate the occurrence mode and mass ratio of sodium,by extraction separation step by step.Moreover,taking WCW coal as the research object,the orthogonal experiment and extreme difference analysis were carried out to investigate the effects of such parameters as temperature,time,coal particle size and agitator speed on the water soluble sodium's removal.The results indicate that,the total mass ratio of sodium in WCW,TCNY and WD coal was 2.329 5 mg/g,2.235 9 mg/g and 0.598 0 mg/g,respectively.The sodium mainly exist in water soluble form.The order of the factors influencing water-soluble sodium's removal is:temperature, time,coal particle size,agitator speed (from strong to weak).At proper temperature,prolonging the reac-tion time,speeding up the agitator and reducing the coal particle size would enhance the removal rate of wa-ter soluble sodium significantely.The best working conditions of removing water-soluble sodium in the ex-periment is,at 70 ℃,with reaction time of 24 h,agitator speed of 200 r/min and coal particle size of 38.5μm to 54 μm.