Tungsten scrap materials

For example, for technical purposes, the dissolution of tungsten scrap material mixtures of NaOH with sodium nitrate or sodiiun nitrite have been widely used. The dissolution occurs due to die following reactions ... 

I. Raw Materials [5.1,5.2,5.6]. There exist three different types of tungstenbearing materials which are currently in use as raw materials for APT production scheelite ore concentrates and wolframite ore concentrates are the primary sources, and various tungsten-containing scrap materials act as secondary sources. 

The oxidation of tungsten in scrap material to the hexavalent state by heating in air or oxygen-eruiched air, because only hexavalent tungsten dissolves in an alkaline leach process. 

Tungsten in most cases is added to the steel melt as master alloy. The two usual types are ferrotungsten and melting base. Due to their lower melting point, master alloys dissolve and distribute more readily in the steel melt as pure tungsten. Moreover, they are cheaper because they are produced either directly fix)m ore concentrates in case of ferrotungsten or from scrap materials in case of melting base alloys. 

It is the high intrinsic value in anything containing tungsten, even in smaller concentrations, which makes tungsten scrap an interesting and worthy material for... 

Typical scrap materials for hydrometallurgical treatment are grinding sludges, floor sweepings, contaminated powder qualities, tungsten-copper, and solid pieces, which can be dissolved by electrolysis. 

Ferro tungsten Tungsten metal powder Tungsten carbide powder Tungsten e scrap Other tungsten materials Total... 

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