水泥生料的燃烧固硫特性及其微观反应机理研究
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摘要: 采用SC-132定硫仪对水泥生料的燃烧固硫特性进行了评价，利用XRD、SEM对煅烧样品进行矿相组成分析及矿物形态分析，讨论了水泥生料高温固硫的微观反应机理。结果表明，高温段固硫物相的热稳定性是影响水泥生料固硫效率的决定因素。水泥生料在较宽温度范围内具有85%以上的固硫效率。850 ℃时已有CaSO4形成， 1 050 ℃时CaSO4开始分解。1050℃～1250℃生成耐高温的硫硅酸钙、硫铝酸钙等复合矿物。1300℃时铁铝酸盐固熔体等将硫酸盐的表面包裹，抑制其高温分解，使水泥生料在1300℃时仍有较高的固硫效率。Abstract: In view of cement calciner technology, the sulfur-fixation properties of cement raw material during its combustion were evaluated by SC-132 sulfur analyzer. The mineral composition and microstructure of calcined sample were analyzed by XRD and SEM. The micro-mechanism of sulfur-fixation reaction at high temperature was discussed. The results show that thermal stability of sulfur retention mineral is a crucial factor in affecting the sulfur-fixation efficiency at high temperature. Cement raw materials have good sulfur-fixation ability within the temperature range tested. The sulfur-fixation efficiency is above 85% at 850 ℃～1 300 ℃. CaSO4 is formed at 850 ℃ and begins to decompose at 1 050 ℃. The thermal-proof complexes of 3CaO·3Al2O3·CaSO4 and Ca5(SiO4)2SO4 are formed at 1 050 ℃～1 250 ℃. The eutectic phase of ferroaluminate and silicate formed at 1 300 ℃ envelop the surface of CaSO4 and suppress its further decomposition, which results in the high efficiency for sulfur-fixation of cement raw materials at 1 300 ℃.
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Key words:
- coal combustion /
- sulfur-fixation /
- cement raw material /
- micro-mechanism of reaction
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