Direct solvent extraction (DSX) was applied to produce purified concentrated Ni and Co solutions from a synthetic sulfuric liquor containing Ca, Cu, Mg, Mn, and Zn as impurities, which simulates the solution obtained by the sulfation-roasting-leaching process after precipitation of Fe, Al, and Cr. The commercial extractants Versatic 10, Cyanex 272, D2EHPA, TBP were used in 3 solvent extraction circuits. In the first circuit, operated at 40 °C, Versatic 10 (0.5 M) fully extracted Cu, Zn, Ni, and Co in 3 stages at O/A = 2:1, and pH 6.5, leaving remaining Mn (54% was extracted) and most of the Ca and Mg in the raffinate. The co-extracted Ca and Mg were fully scrubbed off the loaded Versatic 10 in 2 stages at O/A = 5:1, and pH 6.5. The other metals were stripped out of the Versatic 10 extract using a synthetic Ni spent electrolyte (60 g/L Ni, 2 M HSO) in 2 stages at O/A = 9:1. This loaded strip liquor was subjected to a second circuit with Cyanex 272 (0.64 M) operated at 50 °C. Three stages were required to fully extract Co, Cu, Mn, and Zn (O/A = 2:1, pH 4), whereas the raffinate containing 82 g/L Ni was deemed suitable for electrowinning. The co-extracted Ni(II) was fully scrubbed off the loaded Cyanex 272 in only 1 stage at O/A = 5:1, and pH 4. All Co, Cu, Mn, and Zn were stripped out from the scrubbed loaded Cyanex 272 in 2 stages at O/A = 10:1 using a synthetic Co spent electrolyte (45 g/L Co, 1 M HSO). The raffinate containing 58.4 g/L Co was submitted to a third circuit using a D2EHPA (0.6 M) + TBP (0.73 M) synergistic system operated at 50 °C. Zinc(II) was fully extracted by the D2EHPA + TBP system in 2 stages at pH 2 and O/A = 1:3, while Mn(II) and Cu(II) were fully extracted from the Zn-depleted raffinate in 2 stages at pH 3.5 and O/A = 2:1. The raffinate containing 58.3 g/L Co was deemed suitable for electrowinning. Copper(II), Mn(II), and Zn(II) were stripped out from the loaded D2EHPA + TBP in 3 stages at O/A = 2.5:1 using 1 M HSO. The real number of moles of extractants involved in the extractions and apparent equilibrium constants were estimated for all circuits. A flowsheet of the purification conceptual route is presented.

中文翻译：

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开发概念性直接溶剂萃取 (DSX) 路线和流程图，以生产代表红土硫酸浸出液的纯化浓缩钴和镍溶液


采用直接溶剂萃取 (DSX) 从含有 Ca、Cu、Mg、Mn 和 Zn 杂质的合成硫酸液中生产纯化的浓缩 Ni 和 Co 溶液，模拟沉淀后经过硫酸化 - 焙烧 - 浸出过程获得的溶液Fe、Al 和 Cr。商业萃取剂 Versatic 10、Cyanex 272、D2EHPA、TBP 用于 3 个溶剂萃取回路。在第一个回路中，在 40 °C 下运行，Versatic 10 (0.5 M) 在 O/A = 2:1 和 pH 6.5 下分 3 个阶段完全萃取 Cu、Zn、Ni 和 Co，留下剩余的 Mn（54%萃取）和萃余液中的大部分 Ca 和 Mg。在 O/A = 5:1、pH 6.5 的条件下，共提取的 Ca 和 Mg 分 2 个阶段从负载的 Versatic 10 中完全洗掉。使用合成 Ni 废电解液（60 g/L Ni，2 M HSO）分 2 个阶段（O/A = 9:1）从 Versatic 10 提取物中去除其他金属。该负载的反萃液在 50 °C 下使用 Cyanex 272 (0.64 M) 进行第二个循环。需要三个阶段才能完全提取 Co、Cu、Mn 和 Zn（O/A = 2:1，pH 4），而含有 82 g/L Ni 的萃余液被认为适合电积。在 O/A = 5:1 和 pH 4 条件下，共萃取的 Ni(II) 仅用 1 个阶段就从负载的 Cyanex 272 中完全洗掉。所有 Co、Cu、Mn 和 Zn 均从洗气的负载 Cyanex 中萃取出来272 分 2 个阶段，O/A = 10:1，使用合成 Co 废电解质（45 g/L Co，1 M HSO）。将含有 58.4 g/L Co 的萃余液送至使用 D2EHPA (0.6 M) + TBP (0.73 M) 协同系统的第三回路，在 50 °C 下运行。在 pH 2 和 O/A = 1:3 的条件下，D2EHPA + TBP 系统分 2 阶段充分萃取锌 (II)，而 Mn(II) 和 Cu(II) 则分 2 阶段从贫锌萃余液中完全萃取pH 值 3.5，O/A = 2:1。 含有 58.3 g/L Co 的萃余液被认为适合电解沉积。使用 1 M HSO，在 O/A = 2.5:1 下分 3 个阶段从负载的 D2EHPA + TBP 中萃取出铜 (II)、Mn(II) 和 Zn(II)。估计所有回路中涉及萃取的萃取剂的实际摩尔数和表观平衡常数。提出了纯化概念路线的流程图。