We provide an overview of the current status of research on reprocessing of nickel waste tailings, describe the current condition of the tailings, and set forth an important economic goal — freeing up land occupied by tailings and reducing impacts of human activity on the environment. We study the structure, chemical composition, and phase composition of slag tailings at the Southern Urals Nickel Plant (SUNP). This information was used to design an integrated process for reprocessing of nickel-slag tailings. The first step is to hold the slag/metal melt in a crucible for 15 min at 1300–1400°C, resulting in formation of a nickel-rich (15–18%) matte melt at the bottom. After this melt cools and hardens, it is removed from the crucible, separated from the slag, and inspected in an electron microscope. The resulting matte is suitable for processing into ferronickel via the classical process.

During the second step, the slag from the preceding step was reduced for 30–40 min at 1500–1600°C using crushed electrode, since the low density and porosity of coke mean it is not suitable for this purpose. The slag was vigorously agitated by the release of internal gas. The reduced iron collects to form large inclusions, and settles to the bottom, collecting non-ferrous impurity-metal solutes as it descends. As in the preceding step, the metal was allowed to cool, and the bottom ingot was removed for analysis. We studied the resulting metal, which was used (after preliminary desulfurization) to produce structural steel alloy, and the gangue slag (with Ni and Fe content less than 0.1%) which can be used with blast-furnace slag to produce slag Portland cement. We used these research results to develop a scheme for commercial-scale recycling of SUNP slag waste, with the matte being separated from the slag in an ore smelting furnace, and the iron being separated from the slag in a ladle furnace; in the latter case, the resulting metal can be refined to GOST specifications.

我们概述了镍废尾矿的后处理研究现状，描述了尾矿的现状，并提出了重要的经济目标-释放尾矿占据的土地并减少人类活动对环境的影响。我们研究了南部乌拉尔镍厂（SUNP）的矿渣尾矿的结构，化学组成和相组成。该信息用于设计镍渣尾矿再处理的集成过程。第一步是将炉渣/金属熔体在1300–1400°C下的坩埚中保持15分钟，从而在底部形成富镍（15–18％）的无光泽熔体。熔体冷却并硬化后，将其从坩埚中移出，与炉渣分离，并在电子显微镜下进行检查。

在第二步中，使用破碎电极在1500-1600°C下将前一步骤的炉渣还原30-40分钟，因为低密度和低孔隙率的焦炭意味着它不适用于此目的。通过释放内部气体剧烈搅动炉渣。还原的铁聚集形成大的夹杂物，并沉降到底部，当其下降时收集有色金属杂质金属溶质。与前面的步骤一样，将金属冷却，并取出底部的硅锭进行分析。我们研究了所得到的金属（用于初步脱硫后）以生产结构钢合金，以及可与高炉渣一起用于生产硅酸盐硅酸盐水泥的石渣（Ni和Fe含量小于0.1％）。我们利用这些研究结果制定了一种SUNP炉渣废料的商业规模回收方案，其中在矿石熔炼炉中将磨砂与炉渣分离，而在钢包炉中将铁与炉渣分离。在后一种情况下，可以将所得金属精炼至GOST规格。