Abstract

The results of studying the hydrochloric acid decomposition of the niobium–rare-earth slag produced by reducing roasting of the high-iron rare-earth ore from the Chuktukon deposit are discussed. The slag is presented by four main phases: a glassy phase, a phase with a perovskite structure, a phase with a loparite structure, and a MnAl₂O₄-based spinel phase. Niobium and rare-earth metals in the slag are distributed between the first three phases. The hydrochloric acid leaching of the slag is carried out in two stages: leaching under atmospheric pressure and the solid residue is then leached in an autoclave at high temperatures. The slag starts to decompose at very low acid concentrations (pH 4–2.5), but the maximum development of slag (70%) is reached for leaching with 20% HCl at ~100°C. Under these conditions, only the glassy phase of the slag decomposes. The phases with loparite and perovskite structures decompose at high temperatures in an autoclave. The completeness of their decomposition is achieved at 20% HCl and 200°C for 2 h. According to X-ray diffraction analysis data, the spinel phase weakly decomposes by pressure leaching and remains in the solid phase. The yield of the solid phase is ~12% of the slag weight. Niobium, titanium, and zirconium are nearly completely concentrated in the form of oxides in the solid phase along with the spinel phase. The spinel phase can be removed from the solid residue using magnetic separation. The collective niobium–titanium–zirconium concentrate isolated to a nonmagnetic fraction can further be processed using the chloric method to produce the corresponding metals. The hydrochloric solution formed upon pressure leaching is proposed to be directed to the first leaching stage of the slag at ~100°C. This procedure makes it possible to decrease the hydrochloric acid consumption during leaching to the maximum extent and to substantially facilitate the further recovery of rare-earth metals and manganese by precipitation from weakly acidic solutions.

中文翻译：

---

Chuktukon矿床稀土矿还原焙烧制得的铌稀土矿渣的盐酸分解

摘要

讨论了对来自 Chuktukon 矿床的高铁稀土矿还原焙烧产生的铌稀土矿渣的盐酸分解的研究结果。炉渣由四个主要相呈现：玻璃相、具有钙钛矿结构的相、具有洛帕石结构的相和MnAl ₂ O ₄基尖晶石相。炉渣中的铌和稀土金属分布在前三相之间。矿渣的盐酸浸出分两个阶段进行：在常压下浸出，然后在高压釜中在高温下浸出固体残渣。炉渣在极低的酸浓度（pH 4–2.5）下开始分解，但在 ~100°C 下用 20% HCl 浸出时达到了最大炉渣发展 (70%)。在这些条件下，只有炉渣的玻璃相分解。具有loparite 和钙钛矿结构的相在高压釜中在高温下分解。它们的分解完全是在 20% HCl 和 200°C 下 2 小时实现的。根据X射线衍射分析数据，尖晶石相通过压力浸出微弱分解并保留在固相中。固相的产率约为炉渣重量的 12%。铌、钛和锆几乎完全以氧化物形式与尖晶石相一起在固相中浓缩。可以使用磁分离从固体残留物中去除尖晶石相。分离出非磁性部分的铌-钛-锆集体精矿可以使用氯法进一步加工以生产相应的金属。建议将加压浸出后形成的盐酸溶液直接用于约 100°C 的炉渣第一浸出阶段。该程序可以最大限度地减少浸出过程中的盐酸消耗，并通过从弱酸性溶液中沉淀来显着促进稀土金属和锰的进一步回收。