The authors have proposed an upgrading process for ultramafic nickel concentrates which is comprised of agglomeration of iron powders and concentrates followed by a two-stage thermal treatment at temperatures lower than the typical smelting conditions. This allowed the nickel to migrate from the sulfide phase to metallic ferro-nickel particles, making solid-to-solid contact important. Agglomeration by pelletizing and briquetting has been studied. Moisture added to the pellets caused oxidization of the metallic iron reducing the nickel extraction to ferronickel in the thermal upgrading process. Drying green pellets under vacuum slowed oxidation and resulted in nickel extractions greater than 90 % during thermal upgrading when an H-Ar atmosphere was employed. The presence of H caused about 18 % of sulfur in the concentrate to be released to the off gas when treating pellets, around 2.5 times larger than that released from briquettes treated similarly.

中文翻译：

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团聚对超镁铁质硫化镍精矿中镍提取和硫释放的影响

作者提出了一种超镁铁镍精矿的提质工艺，该工艺包括铁粉和精矿的团聚，然后在低于典型熔炼条件的温度下进行两阶段热处理。这使得镍从硫化物相迁移到金属镍铁颗粒，使得固体与固体的接触变得重要。已经研究了通过造粒和压块进行团聚。添加到球团中的水分导致金属铁氧化，从而减少热升级过程中镍提取到镍铁的量。当采用 H-Ar 气氛时，在真空下干燥生球团可减缓氧化，并在热升级过程中使镍提取率大于 90%。在处理球团矿时，H 的存在导致精矿中约 18% 的硫释放到废气中，大约是经过类似处理的煤球释放的硫的 2.5 倍。