Formation of silica-rich passivation layers formed on the periphery of reacting feed particles is one of the primary obstacles in obtaining high magnesite yields during direct aqueous mineral carbonation of peridotites and serpentinites. The disruption of the silica-rich layer around partially reacted grains as a result of concurrent grinding on the degree of carbonation (magnesite yield) was investigated in this work. Three types of naturally-occurring magnesium silicate feedstocks, dunite, olivine and lizardite, as well as three types of grinding media, were examined.

Discrete size fractions of feed samples, with and without grinding media, were carbonated. SEM readily disclosed the formation of a silica-rich shell around a magnesium rich core during carbonation. EDS analysis was employed to study the elemental composition of reacted particles’ shell and core. The method confirmed that during concurrent grinding these silica-rich layers were removed and continuously produced a fresh surface available for further reaction. The removal of the silica-rich layer was shown to significantly improve magnesite yields up to a 600 % increase in yield. Among the three different grinding media used in this work, zirconia and stainless steel media resulted in similar and highest magnesite yields, which is believed to be due to a combination of their high densities and hardness. The findings of this research showed that enhanced magnesite yields could be achieved for all feedstock without the need for energy intensive pre-treatment steps (e.g. ultrafine grinding and heat-activation). Moreover, concurrent grinding resulted in a magnesite yield when raw lizardite was carbonated.

在橄榄石和蛇纹石的直接矿物水碳酸盐化过程中，在反应进料颗粒外围形成的富硅钝化层的形成是获得高菱镁矿产量的主要障碍之一。在这项工作中，研究了同时研磨对碳酸化程度（菱镁矿产量）造成的部分反应晶粒周围富含二氧化硅的层的破坏。考察了三种天然存在的硅酸镁原料，菱镁矿，橄榄石和蜥蜴石，以及三种类型的研磨介质。

在有或没有研磨介质的情况下，将进料样品的离散尺寸馏分进行碳酸化处理。SEM轻松地揭示了在碳化过程中，围绕富镁核的富二氧化硅壳的形成。用EDS分析法研究了反应颗粒壳和核的元素组成。该方法证实了在同时研磨期间，这些富含二氧化硅的层被去除并连续产生可用于进一步反应的新鲜表面。去除富含二氧化硅的层显示出可显着提高菱镁矿的产率，最高可提高600％的产率。在这项工作中使用的三种不同的研磨介质中，氧化锆和不锈钢介质产生了相似且最高的菱镁矿产量，这被认为是由于它们的高密度和硬度的结合。例如超细研磨和热活化）。此外，当原始蜥蜴石被碳酸化时，同时研磨导致菱镁矿产率。