摘要
利用微波消解法和GB/T 1574-2007两种不同的方法对大南湖二矿原煤制灰,并对灰样中的金属元素的含量进行对比分析。试验结果显示:在国标法制灰过程中,煤中的主要金属元素均有不同程度的逃逸,用金属氧化物逃逸率表征金属元素的逃逸特性,熔点比较高的K_2O和Al_2O_3的逃逸率高达47.92%和42.48%,熔点比较低的CaO的逃逸率达到36.50%,Fe_2O_3逃逸率最小,但也达到10.60%。导致国标灰灰熔融温度升高,与煤实际的结渣特性耦合性差。灰化温度从国标要求的815℃降低到500℃后制得灰的软化温度ST为1200℃,比国标法制得灰的软化温度低70℃。因此,与灰熔融温度相比,灰成分综合预测指数更能体现大南湖二矿煤实际燃用的结渣特性。
The ash melting temperature of Dananhu No.2 Mine coal can not be accurately predicted with its slagging characteristics. In this work, the raw coal samples were investigated to prepare its ash by using microwave digestion technology and the GB/T 1574-2007 standard. The results reveal that in the process of preparing ash by using GB/T 1574-2007 standard, all the main metallic elements in the coal escape to various degrees. The escape rate of K_2O and Al_2O_3 with high melting point were 47.92 % and 42.48 %. The escape rate of CaO with relatively low melting point was 36.50 %, and the escape rate of Fe_2O_3 was the smallest, but also reached to 10.60 %. The ash melting point was affected enormously by the escape of metallic elements, which offends against the actual of coal slagging characteristic. The softening temperature of the ash made under 500 ℃ was 1200 ℃. However, the softening temperature of the ash under GB/T 1574-2007 standard was 1270 ℃. Thus, the practical slag characteristics of Dananhu No.2 Mine coal can be more exactly described with ash composition comprehensive prediction index than with ash melting temperature.
引文
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