中文摘要：

针对现行铌钽矿HF酸处理工艺氟污染严重的问题，提出以KOH溶液替代高毒性HF介质的铌钽矿碱性水热体系浸m新方法，研究了铌钽矿在KOH碱性水热体系浸出规律．结果表明，在KOH质量分数50％范围内，KOH质量分数和反应温度的提高会促进铌钽矿分解生成可溶性六铌（钽）酸钾，但过高的KOH质量分数和反应温度会使可溶性六铌（钽）酸钾向不溶性偏铌（钽）酸钾转化，造成铌、钽浸出率的下降．在KOH质量分数35％、反应温度200℃、碱矿质量比4：1以及反应时间2h的最佳浸出条件下，铌和钽浸出率仅为18．73％和9．4％；通过机械活化对铌钽矿进行预处理后，铌和钽浸出率可大幅度提高至95％和60％，说明机械活化可显著强化铌钽矿碱性水热浸出过程．铌钽矿经机械活化后，矿物粒度减小，比表面积增加，晶格畸变增大，无定形化程度增加，内部缺陷程度增加，矿物的反应活性大大增加，铌钽矿的浸出率显著提高．

英文摘要：

Aiming at serious fluorine pollution problems in current hydrofluoric acid treatment processes of niobium-tantalum ore, a new leaching process of niobium-tantalum ore with an alkaline hydrothermal system was proposed that KOH solution was used as a reaction medium to substitute highly toxic HF solution. The reaction rules of niobium-tantalum ore in the alkaline hydrothermal system were investigated. It is found that decomposition of niobium-tantalum ore into soluble potassium hexa-niobate （tantalate） is promoted by increasing the KOH mass fraction and reaction temperature when the KOH mass fraction range is less than 50%, but soluble potassium hexa-niobate （tantalate） will change to insoluble potassium niobate （tantalate） when the KOH mass fraction and reaction temperature are too high, then the leaching rates of niobium and tantalum decrease. The leaching rates of niobium and tantalum are merely 18.73% and 9.4% respectively under optimum leaching conditions that the KOH mass fraction is 35%, the reaction temperature is 200 ℃, the KOH-to-ore mass ratio is 4：1 and the reaction time is 2 h, but they will increase to 95% and 60% respectively when the ore is mechanically activated. The results indicate that mechanical activation can effectively enhance the leaching process of niobium-tantalum ore in the alkali hydrothermal system. And after the ore is activated, the particle size decreases, the specific surface area enlarges, the degree of lattice distortion increases, the amorphous level and the internal defect degree increase. As a result, the reaction activity of niobium-tantalum ore greatly improves and the leaching rates significantly increase.