Abstract

We investigate the mechanical characterisation of mortars incorporating ferronickel slags (FNS) as partial substitution for cement. The studied slags come from the ferronickel production in New Caledonia. The microstructural characterisation shows that these slags are polycrystalline heterogeneous material mainly composed of forsterite, quartz and enstatite in addition to silica glass. Cement is replaced by up to 20 wt.% of ferronickel slags in the mortars. This upper level of substitution is achieved without compromising mortar’s strengths. For all mixes, the maximum compressive and flexural strengths at all curing ages is obtained with a 5 wt.% replacement of cement by ferronickel slags. The larger effectiveness of FNS is attributed to its larger silica content, which increases the polymerisation degree of the silica chains in the calcium silicate hydrate (C-S-H) structure. Slag recycling reduces the storage time, waste management and environmental impact. It significantly lowers costs related to metallurgical processing. Slag substitution for cement, also lowers the carbon footprint.

摘要

我们研究了掺入镍铁矿渣 (FNS) 作为水泥的部分替代品的砂浆的机械特性。研究的炉渣来自新喀里多尼亚的镍铁生产。微观结构表征表明，这些炉渣是多晶异质材料，除石英玻璃外，主要由镁橄榄石、石英和顽火辉石组成。水泥被砂浆中高达 20 wt.% 的镍铁渣替代。在不影响砂浆强度的情况下实现了这种较高的替代水平。对于所有混合料，在所有养护龄期的最大抗压和抗弯强度是通过用 5 wt.% 的镍铁矿渣替代水泥获得的。FNS 的较大效力归因于其较大的二氧化硅含量，这增加了水合硅酸钙 (CSH) 结构中二氧化硅链的聚合度。炉渣回收减少了储存时间、废物管理和环境影响。它显着降低了与冶金加工相关的成本。矿渣替代水泥，也降低了碳足迹。