Abstract

The diminution of sulfide ore deposit as the main source of nickel extraction initiates the development of alternative methods to maximize the processing of low-grade nickel ore including limonitic laterites. Aiming to produce ferronickel with high nickel content and recovery, the study used sodium thiosulfate and natural sulfur as novel additives to be employed in selective reduction techniques. The reduction process was conducted at 1400 °C for 6 h in a coal–limestone bed. Ores and the as-reduced products were characterized by Emission Dispersive X-Ray (EDX) and X-Ray Diffraction (XRD) to determine the elemental composition in the product and examine the phase transformation of ores. Results showed that utilization of 10%wt Na₂S₂O₃ resulted in a product with 14.31% Ni content and 93.22% recovery, while the employment of 10%wt natural sulfur yielded a product with 13.62% Ni content and its recovery reaching 97.91%. Phase identification of slag product using XRD pointed out that both Na₂S₂O₃ and natural sulfur additives assisted the transformation of ore mineralogy in which the kamacite and taenite phases of metal products confirm the successful formation of ferronickel (Fe, Ni). Furthermore, slag products showed a large amount of iron compound, confirming the fact of low iron recovery.

Graphical Abstract

中文翻译：

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硫代硫酸钠和天然硫：褐铁红土矿石选择性还原的新型潜在添加剂

摘要

硫化物矿床的减少是镍提取的主要来源，这引发了替代方法的发展，以最大限度地处理包括高铁红土的低品位镍矿。为了生产高镍含量和高回收率的镍铁，该研究使用硫代硫酸钠和天然硫作为新型添加剂，用于选择性还原技术。还原过程在煤-石灰石床中于1400°C进行6 h。通过发射色散X射线（EDX）和X射线衍射（XRD）表征矿石和还原后的产品，以确定产品中的元素组成并检查矿石的相变。结果表明，Na ₂ S ₂ O _3的利用率为10％wt得到的产品中镍含量为14.31％，回收率为93.22％，而使用10％（重量）的天然硫则得到的产品中镍含量为13.62％，回收率达到97.91％。利用XRD对炉渣产品进行相鉴定指出，Na ₂ S ₂ O ₃和天然硫添加剂都有助于矿石矿物学的转变，其中金属产品的黄铁矿和石相证实了镍铁（Fe，Ni）的成功形成。此外，炉渣产物显示出大量的铁化合物，证实了铁回收率低的事实。

图形概要