Tungsten Oxide

Ammonium metatungstate (AMT) is one of the most important raw materials and precursors for the preparation of WC. The structure and properties of WC are affected by the physical and chemical properties of precursor. The particle size and structure of precursor will greatly influence the process of reduction and carbonization in the late stage, and then affect the catalytic activity of WC catalyst. In order to obtain precursor with good particle size and good structure, spray drying is usually used. Spray drying has many advantages, such as simple process, no pollution, homogeneous composition, and suitable for mass production. The basic principle of spray drying method is ammonium metatungstate solution by spray drying, in a few seconds, water quickly evaporated into powder, physical and chemical properties of homogeneous granular, hollow spherical or spherical solid products. Many scholars have found that in the spray drying process, the concentration of ammonium tungstate solution h...

  Rubidium, as a rare and weak alkali metal element, has been widely used in organic catalysts, photomultiplier tubes, special glass and anticancer drugs. Rubidium does not have independent minerals, often and other alkali metals coexist in lithium mica, cesium garnet, lithium cesium garnet, natural carnallite, salt lake brine and underground brine. Because of the coexistence of rubidium and sodium and cesium, which are closely related to the physical and chemical properties, the extraction technology of rubidium is very difficult, which results in a large amount of brine rubidium resources not being rationally utilized. The common methods for separation of rubidium and cesium are fractional crystallization, precipitation, solvent extraction and ion exchange. In industrial production, precipitation method is used to separate rubidium and cesium, which is mainly used to separate rubidium and cesium from high content solution. Solvent extraction is easy to realize continuous operatio...

Ammonium paratungstate (APT) is the main raw material for the production of tungsten powder, tungsten carbide powder, tungsten wire and tungsten products. As everyone knows, the tungsten particle size, crystal morphology of its APT has a great "inherited" relationship, so, if want to produce nanometer tungsten powder and tungsten carbide powder, we first need to prepare ultrafine ammonium paratungstate (APT). It is an innovative method to prepare superfine ammonium paratungstate (APT) by microwave ultrasonic combined crystallization. Many scholars have shown that compared with traditional heating crystallization, microwave ultrasonic combined crystallization has obvious advantages in speeding up the crystallization rate, refining the particle size and improving the purity of products. So what's the difference between microwave - ultrasonic combined crystallization and traditional evaporation crystallization? Some scholars have used microwave-ultrasonic combined crystalli...

  In recent years, because bismuth tungstate (Bi 2 WO 6 ) has narrower band gap and wider visible range than titanium dioxide (TiO 2 ), it has a great tendency to replace TiO 2 . However, in practical applications, it was found that bismuth tungate is good, but there are some shortcomings, mainly in its photogenerated electrons and holes easy to complex, quantum efficiency is not high. Therefore, scholars believe that bismuth tungstate should be added with some elements to excite the photocatalytic potential of bismuth tungstate. Some scholars have made Au (Ag) / Bi 2 WO 6  nanocomposites with bismuth tungstate doped with gold or silver. The results show that the degradation efficiency of RhB solution is 40% using Au (Ag) / Bi 2 WO 6  nano photocatalyst, and the efficiency is 99.2%, higher than that of pure Bi 2 WO 6 . Some scholars have suggested that the Pt/Bi 2 WO 6  composite can be used for photocatalytic degradation of Mo methyl orange by doping bismuth with p...