长焰煤的载体浮选试验研究

Study on carrier flotation of long flame coal

为了改善长焰煤浮选效果,提高低阶煤利用率,探究载体浮选对长焰煤浮选效果的提升机理。以陕西榆家梁选煤厂的长焰煤作为浮选入料,内蒙古上海庙选煤厂的-1.3 g/cm3无烟煤作为载体,进行了载体浮选试验研究。对长焰煤进行粒度分析和XRD分析,结果表明:其细粒级含量多且灰分较高,脉石矿物主要为石英和高岭土。细粒度煤泥及黏土矿物的存在,易产生细泥罩盖和机械夹带现象,导致浮选效果较差。首先探究了加入载体的粒级及比例对长焰煤浮选效果的影响。结果发现,随着载体粒径的逐渐减小,其精煤产率逐渐降低,0.5~0.25 mm无烟煤作为载体时,与常规浮选相比,其精煤产率增加了3.89%,精煤灰分降低了0.17%。当载体添加质量比为10∶1时,精煤产率可达到71.93%,精煤灰分为11.48%。通过筛分可将0.5~0.25 mm进行筛分回收,浮选精煤中的载体回收率达到可98.48%,载体得到有效回收。其次探究了长焰煤煤泥粒级对载体浮选的影响,结果发现,0.5~0.25 mm的载体可以有效提高-0.045 mm长焰煤的浮选效果,与单独浮选-0.045 mm煤泥相比,精煤产率提高了9.31%。综上可知,载体浮选主要提高细煤泥的浮选效果。最后通过SEM、絮体图像分析及EDLVO理论计算可知,-0.045 mm长焰煤通过疏水作用力粘附在载体表面,并形成了大量的絮体,从而提高了长焰煤的浮选效果。

In order to improve the flotation effect of long flame coal and the utilization rate of low rank coal,the mechanism of long flame coal by carrier flotation was revealed.In this study,carrier flotation tests were conducted using long flame coal obtained from Shaanxi Yujialiang Coal Preparation Plant as flotation feed and−1.3 g/cm3 anthracite from Shanghai Miao Coal Preparation Plant in Inner Mongo-lia as the carrier.The XRD and particle size analysis of long-flame coal revealed high fine content and ash content,with gangue minerals mainly composed of quartz and kaolin.The existence of fine coal slime and clay minerals led to the production of fine slime cap and mech-anical entraining,resulting in a poor flotation effect.The effect of carrier size and proportion on the flotation effect of long flame coal was investigated.The results indicated that the cleaned coal yield decreased with the decreasing carrier particle size,and that the cleaned coal yield increased by 3.89%while the cleaned coal ash content decreased by 0.17%when 0.5~0.25 mm anthracite was used as the carrier.Furthermore,the carrier recovery rate of flotation cleaned coal reached 98.48%,with the carrier effectively recovered when the carrier pro-portion was 10∶1.Additionally,the influence of long flame coal slime size on carrier flotation was explored.The results revealed that 0.5~0.25 mm carrier could effectively improve the flotation effect of−0.045 mm long flame coal,with the cleaned coal yield increasing by 9.31%compared to the single flotation of−0.045 mm slime.In conclusion,carrier flotation mainly improves the flotation effect of fine slime.SEM,floc image analysis,and EDLVO theoretical calculation demonstrated that the−0.045 mm long-flame coal adhered to the car-rier surface through the hydrophobic force and formed a large number of flocs,thus improving the flotation effect of long-flame coal.