富硅镁镍渣粉磨细度和掺量对硅酸盐水泥水化特性的影响

通过机械粉磨,将富硅镁镍渣(简称"镍渣")粉磨至微米级,制得的镍渣用作水泥混合材部分替代硅酸盐水泥熟料。测试并分析了镍渣的化学组成、细度、筛余量、体积安定性及孔结构。结果表明:4种镍渣的细度均大于硅酸盐水泥熟料,使得水泥颗粒密度随着镍渣掺量增加而减小;镍渣的胶凝活性低于硅酸盐水泥熟料,使得掺有镍渣的水泥粉末水化反应放热量降低,并伴随有缓凝现象,但随镍渣细度提高,有助于改善其反应活性;掺入镍渣不利于硬化水泥砂浆的抗压强度、抗折强度发挥,提高镍渣细度,则由于紧密堆积效应可改善力学性能;镍渣中的MgO不以f-MgO形式存在,使得硬化水泥浆体的体积安定性合格。

Influence of Grinding Fineness and Content of High Silicon-Magnesium Nickel Slag on Hydration Characteristics of Portland Cement

High silicon-magnesium nickel slag(HSMNS)slag was mechanically ground to micro scale powder.The powder was then used to partially replace Portland cement clinker by mixing.The composition of the HSM NS slag,the fineness,the sieving residue,the still stacking property and the pore structure of the HSMNS powder were investigated by the conventional methods.The results obtained in the above experiments show that the fineness of four HSM NS pow der is greater than that of Portland cement clinker,so that the stacking density of the mixture powder mixture decreases with increasing HSMNS conten.The cementitious reactivity of HSMNS is lower than portland cement clinker,so that hydration heat of the cement powders with HSMNS incorporated reduces apparently and retardation phenomenon also appears.However,an increase of HSMNS fineness can improve the reactivity.The compressive strength and flexural strength of the mortars incorporated with HSMNS do not increase with HSMNS content.The mechanical properties can be improved by increasing fineness of HSMNS due to tight packing effect.The MgO phase in HSMNS is not in the form of f-MgO,making the autoclave expansion of the hardened cement pastes is eligible.