This work describes a leaching process for the conversion of high-magnesium peridotite rock, which is a chromite ore overburden, into two valuable products: magnesium salts and micro silica. Under normal leaching conditions, residue remaining after leaching is of a gelatinous nature and thus hinders the filtration process. To address this issue, oxidative leaching with the addition of H 2 O 2 was employed, and it significantly improved the filtration kinetics. Four different approaches for H 2 O 2 addition were tried, and they all proved effective in controlling gelation. The optimum oxidative leaching condition was 70 °C, 2 h time, 2 M H 2 SO 4 , 0.5 M H 2 O 2 and 400 RPM; under these conditions, 92% magnesium leaching efficiency was achieved. After leaching, the leach liquor obtained was purified and dried into Mg(OH) 2 and MgSO 4 salts. The leach residue contained mainly silica particles, with size in the 10–30 μm range. This material thus represents an attractive candidate for the production of high-performance concrete for the construction industry. The oxidative leaching process described here enabled the complete conversion of peridotite into valuable products, magnesium salts and micro silica.

中文翻译：

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铬铁矿覆岩橄榄岩加工成镁盐和微硅粉

这项工作描述了将高镁橄榄岩（铬铁矿覆盖层）转化为两种有价值的产品：镁盐和微硅石的浸出过程。在正常浸出条件下，浸出后残留的残留物具有凝胶状性质，从而阻碍过滤过程。为了解决这个问题，采用了添加 H 2 O 2 的氧化浸出，它显着改善了过滤动力学。尝试了四种不同的 H 2 O 2 添加方法，它们都证明在控制凝胶化方面是有效的。最佳氧化浸出条件为70℃、2h时间、2MH 2 SO 4 、0.5 MH 2 O 2 和400 RPM；在这些条件下，达到了 92% 的镁浸出效率。浸出后，将所得浸出液纯化并干燥成Mg(OH) 2 和MgSO 4 盐。浸出残留物主要包含二氧化硅颗粒，尺寸在 10-30 微米范围内。因此，这种材料是用于建筑行业生产高性能混凝土的有吸引力的候选材料。此处描述的氧化浸出过程使橄榄岩能够完全转化为有价值的产品、镁盐和微硅石。