准东煤矿物分布及其熔融特性变化规律分析

Variation law of mineral distribution in Zhundong coal and the corresponding melting characteristics

对准东煤进行浮沉试验,通过煤灰化学组成和煤灰熔融性分析探讨了矿物在不同密度级中的分布及熔融特性变化。结果表明,不同矿物因成分、密度等差异向不同密度级富集,煤灰化学成分分析显示高密度级比重液富集样品灰化后的Al2O3、Si O2与Fe2O3含量较高,低密度级富集样品灰化后Ca O、SO3与Mg O含量较高,而Ti O2与K2O＋Na2O在各密度级样品灰分中的含量较为稳定。Al2O3、Si O2高温下生成莫来石（3Al2O3·2Si O2）使准东煤灰熔融性温度随密度级呈现升高的趋势。1.5～1.8kg/L密度级富集样品因较低的Si O2和较高的Fe2O3,还原气氛中生成硬绿泥石、铁斜晖石、铁橄榄石等低熔点化合物,煤灰熔融性温度较低。碱酸比、硅比、氧化钠含量、硫分结渣指数等指标表明,准东煤中矿物质经浮沉试验分级偏析后,沾污与结渣特性减弱。

Float- sink test of Zhundong coal is carried out,based on the analysis of ash chemical compositions and the melting characteristics,the variation of mineral distribution and melting characteristics are studied in coal samples with different density. The research results show that, the minerals concentrates to different density levels because of the difference in mineral composition and density. Contents of Si O2,Al2O3 and Fe2O3are higher in the ash of high density level samples,while that of Ca O,Mg O and SO3 are higher in low density levels,and Ti O2 and K2O ＋ Na2 O distribute evenly. The mullite（ 3Al2O3·2Si O2） generated from Al2O3 and Si O2 under high temperature is the main reason for the rising trend of ash fusion temperature along with the increase of density. The coal ash melting temperature of enriched samples from 1. 5 ～ 1. 8kg / L heavy- fluid is low, due to the low Si O2 and high Fe2O3 content, which generates low melting point compounds in reducing atmosphere, such as Al2O3· Si O2· Fe2O3,Fe O · Si O2 and 2Fe O · Si O2.According to the slagging indices,such as acid to alkali,silicon ratio,sodium oxide content and sulfur content, the Zhundong coal shows lower fouling and slagging characteristics after flotation segregation of minerals.