95% fine grain size violet tungsten oxide may be reduced in hydrogen atmosphere to obtain tungsten powder (W powder). And W powder is carbonized to obtain submicron tungsten carbide powder (WC powder). There are some methods for studying the morphology of VTO, W powder and WC powder: 1. Directly observe the morphology of these types of powder in scanning electron microscope (SEM) to know the overall condition. 2. These kinds of powder are made into samples after being dispersed under…

95% violet tungsten oxide nanopowder may be produced by calcining WOx (2≤x≤3) in a closed environment. WOx to Prepare 95% Violet Tungsten Oxide Nanopowder Step one: Feed WOx (2≤x≤3) from the feed end into the heated furnace tube with a feeding device, and gradually move it from low temperature zone to high temperature zone by rotating the inclining furnace tube; Step two: The material continues to move to high temperature zone under the rotation of the inclining furnace tube. When…

Grade 1 violet tungsten oxide nanopowder adopts tungstic acid (mWO3•nH2O, m≥1, n≥1) as raw material. And the VTO may be produced by calcinating and reducing mWO3•nH2O in a hydrogen reducing atmosphere. Hydrogen Reduction Method to Prepare Nano Needle-shaped Violet Tungsten Oxide Step one: By using feeding device, feed tungstic acid from the feed end into the heated furnace tube, and gradually move it from low temperature zone to high temperature zone under the rotation of inclining furnace tube; Step two:…

Super grade violet tungsten oxide nanopowder may be prepared by calcining ammonium paratungstate with formula of 5(NH4)2O•12WO3•5H2O, APT for short. The steps for calcining APT to prepare super grade violet tungsten oxide nanopowder are as follows: Step one: Feed 5(NH4)2O•12WO3•5H2O from the feed inlet into the heated furnace tube with a feeding device, gradually moving from the low temperature zone to high temperature zone under the rotation of inclined furnace tube. Step two: Calcine 5(NH4)2O•12WO3•5H2O to generate WO3, NH3 and…

High-purity violet tungsten oxide nanopowder may be prepared by using tungsten oxide WOx (2≤x≤3) as raw material. Adopt WOx, or WOx generated during preparation as raw material; NH3 and/or H2 are introduced through the air inlet, and water vapor is introduced depending on WOx. If NH3 is introduced, NH3 will react under the catalytic effect of WOx in formula (1) at high temperature: 2NH3=N2+3H2 (1) 1. WOx contains WO3. When the reaction temperature rises above 500°C, WO3 reacts with the…

Crystalline violet tungsten oxide has some difference with crystalline yellow tungsten oxide and crystalline blue tungsten oxide. That is because the oxygen content of these tungsten oxides varies from each other. And it is mainly reflected in appearance, molecular formula, boiling point and other properties. The difference between violet tungsten oxide and yellow tungsten oxide and blue tungsten oxide is shown as below: 1. Violet Tungsten Oxide (1) Also known as γ-tungsten oxide, abbreviated for VTO; (2) Appears violet or…

Submicron grain size violet tungsten oxide’s morphology is the most special one among tungsten oxides including yellow tungsten oxide, violet tungsten oxide, blue tungsten oxide and brown tungsten oxide. The morphology of VTO is a needle-shaped crystal like APT crystal form. The quality of submicron violet tungsten oxide directly affects the production and quality of tungsten powder and tungsten carbide powder. Therefore, how to judge the quality of violet tungsten oxide is becoming the emphasis of studying. Determining the quality…

Violet tungsten oxide nano powder may be produced by adopting tungstic acid mWO3•nH2O (m≥1, n≥1) as raw material. 1. Tungstic acid heated above 100°C: mWO3•nH2O=mWO3+nH2O (1) Introduce NH3, the introduced NH3 reacts in the formula (2) under the catalytic action of tungsten oxide WOx (2≤x≤3): 2NH3=N2+3H2 (2) 2. When the reaction temperature rises above 500°C, the reaction product WO3 in formula (1) and the reaction product H2 in formula (2) undergo the reduction reaction in formula (3): WO3+0.1H2=WO2.9+0.1H2O (3) If…

95% violet tungsten oxide refers to a violet tungsten oxide powder with W18O49 purity of 95% and WO3 content of 5%. Chinatungsten Online provides this kind of violet tungsten oxide with grain size of 10~18μm and density of 1.75g/cm3. Chinatungsten Online provides 95% violet tungsten oxide, that is, grade A1 of violet tungsten oxide. The impurity content (%) is as follows: Sn≤0.00005; S≤0.0005; Cu≤0.0010; Mo≤0.00005; Bi≤0.0005; As≤0.0005; P≤0.0005; Si≤0.0005; Ca≤0.0001; Mn≤0.00005; Ti≤0.0002; Mg≤0.0002; Na≤0.0004; K≤0.0006; Cr≤0.0002; Sb≤0.0001; V≤0.0002; Co≤0.0002; Ni≤0.0002;…

Nano violet tungsten oxide may be prepared by using ammonium paratungstate 5(NH4)2O•12WO3•5H2O as raw material. 1. Ammonium paratungstate heated above 400°C, the reaction in formula (1) occurs: 5(NH4)2O•12WO3•5H2O=12WO3+10NH3+10H2O (1) The reaction product NH3 in the formula (1) or NH3 introduced in other ways reacts in the formula (2) under the catalytic action of tungsten oxide WOx (2≤x≤3) to generate reducing gas hydrogen H2. 2NH3=N2+3H2 (2) 2. When the reaction temperature rises above 500°C, the reaction product WO3 in formula (1)…