我国高灰熔融温度煤储量巨大,灰中硅铝含量高,而部分污泥中碱性氧化物含量高,将其与高灰熔融温度煤共气化为高灰熔融温度煤灰熔融特性的调控提供了可能。研究了城市污泥(CS)和制药污泥(ZY)对高灰熔融温度焦作煤(JZ)灰熔融特性的影响。结果表明:向JZ灰中添加CS灰和ZY灰均可降低其灰熔融温度,添加ZY灰对JZ灰熔融温度降低效果更明显;CS灰和ZY灰的添加比例分别为15%和10%时,2种混合灰的流动温度降至1380℃以下,满足气流床气化液态排渣要求。CS灰CaO含量高,ZY灰Fe2O3含量高,随污泥灰添加,CS灰中CaO与Al2O3和SiO2反应生成的钙长石增多,其与石英发生共熔导致液相含量增加降低了灰熔融温度;弱还原气氛下JZ-ZY灰中Fe3+被还原为Fe2+,并使生成的铁尖晶石等铁系矿物质增多,低熔点铁尖晶石在低温下熔融及铁系矿物质与其他物质发生的低温共熔降低了JZ灰熔融温度。污泥灰添加比例相同时,与JZ-CS灰相比,JZ-ZY灰中理论固相含量更低;晶相衍射峰强度和数量更低;1500℃时,ZY灰占比25%的混合灰达到全液相状态,而CS灰占比25%的混合灰中仍有部分莫来石。摩尔离子势α与2种混合灰的特征温度均呈线性正相关。JZ-ZY灰的α降幅更大,因此JZ-ZY灰熔融温度降低更明显。

The reserve of high ash fusion temperature coal in China is huge, and the content of silicon and aluminum in the ash is high,while the content of basic oxide in some sludge is high. The co-gasification of sludge and high ash fusion temperature coal provides thepossibility of regulating the ash melting characteristics of high ash fusion temperature coal. In this study, the effects of municipal sludge(CS) and pharmaceutical sludge (ZY) on the ash melting characteristics of Jiaozuo coal (JZ) with high ash fusion temperature wereinvestigated. The results show that adding CS ash and ZY ash to JZ ash can reduce ash fusion temperature of JZ and adding ZY ash hasa more significant effect on reducing the ash fusion temperature of JZ. When the CS and ZY ash ratio is 15% and 10%, respectively,the flow temperature of JZ-CS and JZ-ZY mixtures are reduced to below 1 380 ℃ to meet the slag discharge requirements of entrainedflow gasifier CS ash has a high CaO content, and ZY ash has a high Fe2O3 content. With the addition of CS ash, the amount of anorthiteformed by reaction of CaO in CS ash with Al2O3 and SiO2 increases,and its co-melting with quartz results in the increase of liquidphase content and the decrease of ash melting temperature. Under a weak reducing atmosphere, the Fe3+ in JZ-ZY ash is reduced intoFe2+, and iron-bearing minerals such as hercynite increases. Hercynite with low melting point can melt at low temperature, and ironbearing minerals easily form low melting point eutectic with other minerals, which decreases the ash fusion temperature (AFT) of JZ.When the proportion of sludge ash added is the same, compared with JZ-CS ash, JZ-ZY ash has a lower theoretical solid content, low⁃er intensity and quantity of crystal phase diffraction peaks. When the temperature is 1 500 ℃ , the mixed ash with 25% ZY ash reachesthe full liquid state, while the mixed ash with 25% CS ash still contains some mullite. Mole ionic potential α is positive linearly correla⁃ted with the characteristic temperatures of both types of mixed ash. The decrease in α value of JZ-ZY ash is greater, so the melting tem⁃perature of JZ-ZY ash decreases more significantly.

0 引言

1 试验

   1.1 试验原料

   1.2 混合灰的制备

   1.3 灰熔融特征温度的测定

   1.4 高温渣样的制备

   1.5 灰化学组成分析

   1.6 矿物质组成分析

   1.7 热力学平衡计算

   1.8 红外光谱（FT-IR）分析

2 结果与讨论

   2.1 样品灰熔融特性分析

   2.2 污泥对煤灰熔融特性的影响

   2.3 混合灰的理论矿物质组成模拟

   2.4 混合灰的SiO2-Al2O3-CaO三元相图分析

   2.5 混合灰矿物质组成的演变

   2.6 污泥对煤渣结构的影响

   2.7 摩尔离子势α与熔融温度的关系

3 结论