The selective cementation of cadmium, cobalt, and nickel from synthetic and an industrial zinc sulfate (150–160 g.L⁻¹) electrolyte was investigated. The desired cadmium removal (from 640 to 740 mg.L⁻¹ to <1 mg.L⁻¹) was achieved at ambient temperature, with staged addition of zinc dust, using a Zinc/Metals molar ratio in excess of 300%, which is about 50% lower than typical ratios used in industries. An enriched Cd cement (29% wt. vs. app. 7% wt. in industrial samples) with low nickel (0.05% wt.) content was produced in one purification stage. The zinc content in the Cd cement was 20% lower relative to that in the industrial cement. In a second stage, fast and high cobalt and nickel removals were obtained after the pre-activation of zinc dust with copper and antimony. The presence of 150–160 g.L⁻¹ Zn did not affect cobalt removal but made it difficult for nickel cementation. The industrial specification for the purified solution that feed the zinc electrowinning process was achieved for cobalt (< 0.2 mg.L⁻¹) and nickel (< 0.5 mg.L⁻¹), after 60 min of reaction time. The nature, morphology, and chemical composition of the cementation products were evaluated by X-ray diffraction analyses and electron microscopy techniques. Finally, an alternative two-stage purification flowsheet was proposed to produce a rich cadmium cement with low nickel content (0.05% wt.), and a cobalt‑nickel cement. The process allows for a reduction in the consumption of zinc dust and energy, as well as the reaction time.

研究了从合成和工业硫酸锌（150–160 gL ^-1）电解质中选择性地胶结镉，钴和镍。所需的镉去除量（从640至740 mg.L ^-1至<1 mg.L ^-1）是通过在环境温度下分阶段添加锌粉来实现的，锌/金属摩尔比超过300％，比工业上使用的典型比率低约50％。在一个纯化阶段中生产出了镍含量低（0.05％重量）的富镉水泥（29％重量，工业样品中约为7％重量）。Cd水泥中的锌含量比工业水泥中的锌含量低20％。在第二阶段中，用铜和锑对锌粉进行预活化后，可以快速，高效地去除钴和镍。150–160 gL ^-1 Zn的存在不会影响钴的去除，但很难进行镍的胶结。钴（<0.2 mg.L ^-1）达到了供入锌电解沉积工艺的纯净溶液的工业规格在60分钟的反应时间后）和镍（<0.5 mg.L ^-1）。通过X射线衍射分析和电子显微镜技术评价了胶结产物的性质，形态和化学组成。最后，提出了另一种两步纯化流程，以生产低镍含量（0.05％wt。）的富镉水泥和钴镍水泥。该方法可以减少锌粉和能量的消耗以及反应时间。