长焰煤浮选精煤表面特性研究

A study on surface property of long-flame coal's flotation concentrate

为了研究低阶煤中的长焰煤浮选前后的表面性质变化,首先对其密度和粒度组成进行分析,得知长焰煤煤样的主导密度级为1. 3～1. 4 g/cm^3,主导粒级为0. 25～0. 5 mm;然后对煤样进行浮选速度试验,判断煤泥可浮性为中等可浮。通过傅立叶红外光谱分析、XPS分析、电位仪检测、比表面积自动测定仪检测煤样浮选前后的表面性质,结果得出:与原煤相比,浮选后得到的精煤碳含量增加,氧含量降低,Zeta电位绝对值和比表面积降低。浮选初始得到的精煤J1和浮选后期得到的精煤J4含氧官能团较少,精煤J3碳含量最高,为81. 51%,且精煤J3氧含量最低,为17. 34%。最后提出了从分析低阶煤的表面性质出发,着重浮选药剂研制的建议。

In order to make known the change of surface property of long-flame coal, a low-rank coal, before and after flotation, a density and size analysis of the coal is first made. It is observed through analysis that the density and size consists of the coal are predominately in a range of 1.3-1.4 g/cm3 and 0.25-0.5 mm respectively. Then flotation rate test made with coal sample reveals that the coal belongs to a moderately floatable coal. Result of analysis of the variation of surface property of long-flame coal using Fourier transform infrared spectrometer （FTIR）. X-ray photoelectron spectrometer （XPS）, zeta-potential meter and automatic specific surface area meter indicates that： in comparison with the raw coal, the concentrate yielded through flotation has a higher content of carbon and a reduced content of oxygen; the absolute value of zeta-potential and specific surface area both drop down; the concentrate J1 obtained at initial flotation stage and the concentrate J4 yielded at the final stage all show a decrease in the amount of oxygen functional groups; and the concentrate J3 has a highest content of carbon of up to 81.51% and a lowest content of oxygen which is only 17.34%. It is proposed at the end of the paper that stress needs to be placed on the R ＆ D of the flotation reagent which is highly adaptable to change of surface property of low-rank coal.