摘要:
The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner.
摘要:
The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner.
摘要:
The invention is directed to ammonium paratungstate decahydrate containing at least 75% of crystals having a length of at least 200 μm and having a ratio of length to width of less than 4.5:1.
摘要:
A method for preparing ammonium heptamolybdate with the steps of: i) adding a molybdenum-containing organic phase to a liquid-liquid reextraction apparatus or to a desorption apparatus, and ii) directly cold-crystallization ammonium heptamolybdate by cooling the resulting reextraction or desorption solution.
摘要:
The invention relates to a process for recovering valuable metals from a superalloy which has the steps of digesting the superalloy in a salt melt. The salt melt contains 60-95% by weight of NaOH and 5-40% by weight of Na2SO4.
摘要翻译:本发明涉及一种从超级合金中回收有价值金属的方法,该方法具有在盐熔体中消化超合金的步骤。 盐熔体含有60-95重量%的NaOH和5-40重量%的Na 2 SO 4。
摘要:
The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH3:W molar ratio of from 0.83 to 1.30, and a volume feed ratio of the tungsten-laden organic phase to the ammonia-containing aqueous solution of from 5 to 25. The above crystalline is in high purity and in high yield. The production method can be carried out in a simple and energy-efficient manner.
摘要:
The invention is directed to a method for the production of ammonium paratungstate tetrahydrate by thermal treatment of ammonium paratungstate decahydrate in an aqueous suspension. The ammonium paratungstate tetrahydrate can be produced with high purity and high yield. The production method may furthermore be carried out in a simple and energy-efficient manner.
摘要:
The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH3:W molar ratio of from 0.83 to 1.30, and a volume feed ratio of the tungsten-laden organic phase to the ammonia-containing aqueous solution of from 5 to 25. The above crystalline is in high purity and in high yield. The production method can be carried out in a simple and energy-efficient manner.
摘要:
A method for preparing ammonium heptamolybdate with the steps of: i) adding a molybdenum-containing organic phase to a liquid-liquid reextraction apparatus or to a desorption apparatus and adding an ammonia-containing aqueous solution to this reextraction or desorption apparatus, and ii) directly cold-crystallizing ammonium heptamolybdate by cooling the resulting reextraction or desorption solution.
摘要:
A process for reducing the content of alkali metal impurities (e.g., potassium) in ammonium metallate solutions is described. The process involves subjecting a feed solution containing ammonium metallate and alkali metal impurities to membrane filtration. The membrane filtration results in the formation of a retentate having a reduced level alkali metal relative to the feed solution, and a permeate containing substantially the balance of alkali metal. The permeate may also be further treated, to remove alkali metal there from, by passage through a cation exchange column, thereby forming a cation exchange treated permeate that may be combined with the retentate of the membrane filtration step.