Abstract For decades, methods for leaching scheelite based on the generation of soluble phosphotungstic heteropoly acids have been continuously studied. These methods can be performed under normal pressure and can achieve a high leaching ratio when treating scheelite, but their most obvious disadvantage is that the leaching speed is very slow when treating wolframite, which has limited their application in the leaching of wolframite-containing ores. Considering the difference between the crystal forms of these two minerals, the relationship between the crystal structure of MeWO4-type tungstate and the leaching rate in acid solution containing phosphoric acid was systematically studied. The results showed that the leaching rates of all tetragonal tungstates were significantly higher than those of monoclinic and triclinic tungstates. Even in H3PO4-H2SO4 solution, sulfate precipitates were produced when leaching tetragonal tungstates, but their leaching rates were still significantly higher than those of other crystalline tungstates. In addition, the tungsten leaching rate was roughly proportional to the volume occupied by the MeWO4 unit, and NiWO4, with the closest-packed atomic arrangement, had the lowest leaching rate. It was found that the evolution of the tungstate crystal structure parameters was gradual and regular with the gradual change in the CX (cилoвыe xapaктepиcтики, obtained by the ratio of a cation's n-th ionization potential to its orbital radius), although these divalent cations are in different regions of the periodic table. Furthermore, leaching in the acid solution containing phosphoric acid yielded a better relationship between the change in the tungsten leaching rate and the change in the cation's CX in the same group or period of the periodic table.

中文翻译：

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钨酸盐在含磷酸酸溶液中的浸出行为研究

摘要 几十年来，人们不断研究基于产生可溶性磷钨杂多酸的白钨矿浸出方法。这些方法可以在常压下进行，处理白钨矿时可以达到较高的浸出率，但最明显的缺点是处理黑钨矿时浸出速度很慢，限制了它们在含黑钨矿浸出中的应用。考虑到这两种矿物晶型的差异，系统研究了MeWO4型钨酸盐的晶体结构与在含磷酸的酸溶液中浸出率的关系。结果表明，所有四方晶系钨酸盐的浸出率均显着高于单斜晶系和三斜晶系钨酸盐。即使在H3PO4-H2SO4溶液中，浸出四方钨酸盐时也会产生硫酸盐沉淀，但其浸出率仍显着高于其他晶态钨酸盐。此外，钨浸出率与 MeWO4 单元所占的体积大致成正比，而 NiWO4 原子排列最密，浸出率最低。发现钨酸盐晶体结构参数的演变是逐渐且有规律的，随着 CX 的逐渐变化（cилoвыe xapaктиcтики，通过阳离子的 n 次电离势与其轨道半径的比值获得），尽管这些二价阳离子是在元素周期表的不同区域。此外，