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钨矿石中亚铁的测定,可以用硫、磷混合酸溶矿,五价钒容量法.但该法在加热分解试样过程中,五价钒的还原与加热时间的长短及温度的高低都有关系.虽然加入四价钒后稳定性有所改善,但仍不能完全克服这个弊病.我们通过试验证明,选择高锰酸钾于浓磷酸中加热制成三价锰磷酸溶液比较满意.三价锰在浓磷酸中形成很稳定的紫红色络合物,经室温保存十天或置于近300℃的电炉上加热煮沸至波面趋于平静(不能冒磷酸烟超过1分钟),其浓度均未变化.据此,
Tungsten ore ferrous determination, you can use sulfur, phosphorus mixed acid dissolution, pentavalent vanadium volume method, but the law in the process of heating and decomposition of the sample, the pentavalent vanadium reduction and heating time length and temperature are Although the stability after adding vanadium tetravalent has been improved, but it still can not completely overcome this malady.We have proved through experiments that the choice of potassium permanganate in concentrated phosphoric acid is heated to make the manganic phosphoric acid solution more satisfactory. Manganese in concentrated phosphoric acid to form a very stable fuchsine complex, stored at room temperature for ten days or placed in an electric furnace near 300 ℃ boil until the wave surface tends to calm (can not take phosphoric acid smoke more than 1 minute), the concentration was not Change.Accordingly,