Method for determination of molybdenum trioxide and/or tungsten trioxide content of high-molybdenum tungsten ore

Abstract

The invention discloses a method for determination of molybdenum trioxide and / or tungsten trioxide content of high-molybdenum tungsten ore. The method comprises the following steps of 1, dissolving a sample by hydrochloric acid, nitric acid and perchloric acid in the presence of a small amount of ammonium fluoride so that tungsten is separated out in a form of tungstic acid and a part of molybdenum is separated out in a form of molybdic acid, 2, carrying out filtration so that tungsten and molybdenum are separated from a large proportion of coexistence elements, dissolving the tungstic acid and the molybdic acid by ammonia water, carrying out drying and calcination of the filtrate, removing silicon by hydrofluoric acid, carrying out calcination, and weighing the total amount of tungsten trioxide and molybdenum trioxide, 3, dissolving tungsten trioxide and molybdenum trioxide by sodium hydroxide, determining the amount of molybdenum trioxide by a thiocyanate absorption photometry method, and 4, determining mass fractions of tungsten trioxide in the residues and the filtrate by the thiocyanate absorption photometry method, and carrying out result correction. The method solves the problem that because of molybdenum influence, the conventional tungsten trioxide analysis method produces content determination values higher or lower an actual value and is unstable. The method is simple and feasible and realizes accurate and stable analysis and detection of molybdenum trioxide and / or tungsten trioxide content of high-molybdenum tungsten ore.

Description

technical field [0001] The invention relates to a method for analyzing and detecting molybdenum and / or tungsten elements, in particular to a method for determining the content of molybdenum trioxide and / or tungsten trioxide in high-molybdenum-tungsten ores. Background technique [0002] In the prior art, the determination of tungsten trioxide content in tungsten ore mainly includes ammonium tungstate ignition gravimetric method, 8-hydroxyquinoline gravimetric method, and thiocyanate absorptiometry. Among them, the thiocyanate absorptiometry is suitable for the determination of low tungsten trioxide content in ores, and the ammonium tungstate ignition gravimetric method is mainly used for the determination of high content of tungsten trioxide in tungsten ores without niobium, tantalum and molybdenum. The 8-hydroxyquinoline gravimetric method is suitable for the determination of high content tungsten trioxide in tungsten ores containing niobium, tantalum and molybdenum. [00...

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Problems solved by technology

[0003] Because tungsten and molybdenum often co-exist together, tungsten ore often contains a relatively high content of molybdenum, and more than 0.5% molybdenum in tungsten ore will interfere with the determination of tungsten. If the influence of molybdenum is not removed, it cannot be determined. The exact content of tungsten trioxide

[0004] However, due to the similar properties of tungsten and molybdenum, it is difficult to separate them. The classic ammonium tungstate ignited gravimetric method often results in significantly higher and unstable determination results due to the influence of molybdenum, while the 8-hydroxyquinoline gravimetric method requires After two times of filtration, the pH of the solution is adjusted twice, the process is long, and the precipitation in the platinum dish needs to be strictly controlled when the temperature is ashed on the electric furnace, and the measurement results are often unstable due to the operating conditions such as temperature and pH. low

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