In this paper, we suggest a novel recycling process for hard metal sludge that does not use ammonium paratungstate. Ammonia, which in the conventional is essential removing sodium and crystallized tungstate, was used process. Instead of ammonia, acid to remove tungstate resulting formation tungstic (H2WO4). Tungsten powders were successfully synthesized by hydrogen reduction through H2O decompo...

The existing processes for obtaining black wear-resistant coatings include chemical methods, anodic oxidation followed by painting in aniline dyes, electrochemical deposition, vacuum plasma treatment, microarc (MAO). Of great interest the formation of light-absorbing is MAO method, which characterized as a reliable and environmentally friendly process, provides hard ceramic-like oxide layer wit...

Heavy metal tungsten alloys have replaced lead and depleted uranium in many munitions applications, due to public perception of these elements as environmentally unsafe. Tungsten materials left in the environment may become bioaccessible as tungstate, which might lead to population exposure through water and soil contamination. Although tungsten had been considered a relatively inert and toxico...

Tungstate-catalyzed hydrogenolysis of sugars in untreated woody biomass to ethylene glycol (EG) has so far been unsuccessful. This work shows that production EG is predominantly hampered by the presence inorganic impurities biomass, which can be selectively removed an acid leaching step at room temperature. Catalytic and acid-leached samples was run 245 °C using sodium polytungstate Raney Ni ca...

Sorption of tungstate on boehmite (γ-AlOOH) is increased by co-sorption with Co2+ over the near-neutral pH range. Batch uptake experiments show up to a 3-fold increase in tungstate uptake over the range WO42-=50-1000μmol/L compared to boehmite not treated with Co2+. Desorption experiments reveal a corresponding decrease in sorption reversibility for tungstate co-sorbed with Co2+. Reaction of bo...

Time-of-flight neutron powder diffraction data have been collected from Na2MoO4 and Na2WO4 to a resolution of sin (θ)/λ = 1.25 Å(-1), which is substanti-ally better than the previous analyses using Mo Kα X-rays, providing roughly triple the number of measured reflections with respect to the previous studies [Okada et al. (1974 ▶). Acta Cryst. B30, 1872-1873; Bramnik & Ehrenberg (2004 ▶). Z. Ano...