Abstract:

The fusibility and flow properties of Shell gasifier slag were study in this paper.The physical properties of slag were analyzed with X-ray fluorescence, X-ray diffraction, and scanning electron microscopy.The fusion temperature, viscosity and lowestm tapping temperature for slag with the addition of fluxing CaO were measured by using high temperature fusion furnace and high temperature rotational viscometer.The thermodynamic computer package FactSage was used to predict the proportion of solid, the liquidus temperature as well as the mineral phase formed as a function of composition and temperature.The results showed that the fusion temperature, lowest tapping temperature and viscosity of slag in the temperature range of 1400—1500℃ decreased with increasing CaO content, whereas those values increase rapidly with CaO content higher than 35%.The effect of CaO on the liquidus temperature and the solid content at the same temperature calculated by FactSage was similar.The sub-liquidus phase predicted by FactSage transformed from the anorthite phase to the mullite phase with increasing CaO content.Also, the microstructure of quenched slag changed from a loose and porous state to rod-like crystallization.

Key words:

灰渣, 熔融性, 黏度, 全液相温度, FactSage

摘要：

分析了Shell气化炉中灰渣的物理性质，同时利用灰熔点测定仪、高温黏度计测定了添加适量助熔剂CaO的灰渣熔融温度和黏度，并利用热力学软件FactSage计算了灰渣在不同温度下对应的固液相的相对含量及全液相温度。研究结果表明：由于灰渣中主要结晶矿物中熔点较高矿物质如莫来石的含量在不断减少而熔点较低矿物质如钙长石的含量在不断增加，使得灰渣的熔融温度随着CaO含量的增加先降低而后升高。同时从灰渣的微观结构中可知，随着CaO含量的增加，灰渣的液相区面积先增大而后减少，这使得气化炉的最低排渣温度和高温下的灰渣黏度也随着CaO含量的增加呈先降低而后升高的变化趋势。同时由热力学软件FactSage计算出的灰渣全液相温度和相对固含量随CaO含量的变化趋势与灰渣的熔融温度、黏度的变化趋势一致。

关键词:

灰渣, 熔融性, 黏度, 全液相温度, FactSage