燃煤灰渣水化反应动力学测定方法研究

Method for Determining the Hydration Reaction Kinetics of Coal Ashes

煤粉炉粉煤灰、沸腾炉渣和循环流化床固硫灰渣是3种具有代表性的燃煤灰渣.采用氢氧化钙变化量和化学结合水量表征方法,对燃煤灰渣的水化反应动力学进行研究.研究发现,由于燃煤灰渣中游离CaO的存在,用Ca(OH)2反应变化量研究其水化反应动力学时存在较大的干扰和误差;而用化学结合水量法则不受燃煤灰渣中游离CaO和SO3含量的影响,且与28d抗压强度比方法所得结果相一致.结果表明,随着龄期增长,固硫灰渣或沸腾炉渣-水泥胶凝系统中,水化产物生成量明显高于粉煤灰-水泥胶凝系统;燃煤灰渣的火山灰活性与其CaO或SO3含量不存在必然联系.

Ashes from pulverized coal combustion（PCC） boiler,bubbling fluidized bed combustion（BFBC） boiler and circulating fluidized bed combustion（CFBC） boiler,namely,PC ashes,BFBC ashes and CFBC ashes respectively,are representative coal ashes.The hydration reaction kinetics of coal ashes was investigated by the change of Ca（OH）2 and chemically combined water content.It is found that there are some disturbances and errors for the study of the hydration reaction kinetics of coal ashes by means of the change of Ca（OH）2 content,while the method of chemically combined water content is independent of the content of free lime or SO3,in accordance with the results of 28 d compressive strength ratio.The results confirm that the content of the hydration products of BFBC ashes or CFBC ashes-cement pastes is greater than that of PC ashes-cement pastes,and the pozzolanic activity of coal ashes is not closely related to the content of CaO or SO3.