蛭石对高钠高钙准东煤结渣特性影响研究

采用一维沉降炉,辅以灰熔点仪的实验方法,将蛭石与高钠高钙准东煤掺混燃烧,研究其对高钠高钙准东煤结渣特性的影响。结果表明,随着蛭石掺烧量的提高,灰熔点温度呈现先降低后升高的趋势,当掺烧量为6%时灰熔点温度最低;蛭石掺烧量越高,高钠高钙准东煤结渣情况改善越明显,当掺烧量达到4%时,渣样变得疏松多孔,质地变脆,渣样与沉积探针之间的黏附性较弱,极易通过吹灰除去,建议蛭石掺烧量为4%;煤灰中原始矿物质以石英、钙铝黄长石或钙黄长石以及辉石类的低熔点矿物质为主,掺烧蛭石后,含钠的绿辉石矿物质被转化为韭闪石,含铁的斜辉石、赤铁矿等矿物质被转化为铁橄榄石,渣样中的矿物质均以高熔点的镁橄榄石为主;蛭石具有固钠的作用,取样温度越低,蛭石掺混量越高,其固钠效果越明显。

Effect of vermiculite on the slagging characteristics of high sodium and high calcium Zhundong coal

The effect of vermiculite on the slagging characteristics of high-sodium and high-calcium Zhundong coal was studied by a drop-tube furnace and with ash fusion tester. The results show that with the increase of the amount of vermiculite blended, the ash melting point temperature first decreases and then increases. When the ratio of blending is 6%, the ash fusion point temperature is the lowest. The higher the blending ratio is, the more obvious the improvement of the slagging condition of Zhundong coal is. When the ratio of blending is 4%, the slag sample becomes loose and porous, the texture turns to be brittle, and the adhesion between the slag sample and the deposition probe is weak, being easy to be removed by soot blowing. It is recommended that the amount of vermiculite blended should be 4%. The original mineral in coal ash is mainly composed of quartz, gehlenite and low fusion point minerals of pyroxene. After blending vermiculite, the omphacite, sodium-containing minerals, is converted into pargasite, and the iron-bearing minerals such as augite and hematite are converted into forsterite ferroan, and the minerals in the slag sample are mainly forsterite, which has a high fusion point. Sodium can be captured by vermiculite. With the sampling temperature decreasing and the vermiculite blending ratio increasing, the effect of sodium capture becomes more and more obvious.