【Chinatungsten】tungsten trioxide and calcium hydroxide reaction

Tungsten oxide is yellow powder with stable chemical property and anti acid ability. But it can be dissolved in alkali solution such as NaOH, KOH, Ca(OH)2 which will become tungstate.

Calcium hydroxide chemical formula is Ca(OH)2, it is white powder. Also called as slaked lime, hydrated lime. Tungsten trioxide and calcium hydroxide reaction is as following：

WO3+Ca(OH)2=CaWO4+H2O

Ca2WO4 is calcium tungstate which is also called artificial scheelite. It is important chemical raw material and mainly be used to produce APT, WO3, ferro tungsten, steel alloy, tungsten carbide, tungsten products, tungsten wire, tungsten alloy and other tungsten products. Besides that, other emerging industry such as fluorescent paint, screen pipe for shoot, X-ray and day light.

【Chinatungsten】tungsten-copper-sol-gel-method

Introduction

Tungsten copper sol gel method with hydrolysis and polymerization basic reaction, which are in preparation of high purity at a low temperature, evenly distributed, high chemical activity of single and multi-component mixtures. It is a metal alkoxide and its compounds as raw materials, under certain conditions hydrolysis medium and catalyst - the polycondensation reaction solution into a gel, and then by drying and heat treatment method of obtaining synthetic materials.

Processing

Compared with conventional sintering method, sol gel method products with high uniformity and high purity, the temperature is 400℃~500℃ lower than conventional sintering method, the reaction process is easy to control, can greatly reduce the side effects of the new phase formed. At the same time, this kind of method solve the mechanical mixing powder prepared tungsten copper composite powder particle size is too large, mechanical impurities, tungsten copper mixing uneven and other issues.

【Chinatungsten】tungsten-copper-spray-drying-method

Introduction
Tungsten copper spray drying method also called thermo-chemical synthesis method involves the preparation of the original solution and mixing, spray drying and fluid bed conversion in three stages. It is the solution to obtain chemical and physical atomized ultrafine particles by the method of combining physical means.

Process
Tungsten copper precursors prepared by spray drying a powder is generally spherical hollow shell, spray dried powders must be converted to a fluidized bed to give the corresponding metal composite powder. First, a variety of mixed metal salt solution to obtain a mixed solution, such as ammonium paratungstate or ammonium metatungstate and other metals Cu, Ni, Fe is mixed into the aqueous metal salt solution after the atomizer.

The spray from the nozzle into the drying chamber to obtain high speed metal salt particles, collected after firing, to obtain ultrafine particles nanocrystalline oxide composite powder precursors, shaped like a spherical shell-like powder. Then the precursor powder under certain conditions through the reduction or charring, to obtain the desired component monopropellant, multi-component alloy composite powder or carbide.

【Chinatungsten】tungsten trioxide target

Tungsten trioxide target is often used as the evaporation material of WO3 thin film. Producing process of tungsten trioxide target adopting electric ceramic, process is ball milling, compression moulding and calcination.

During the producing process, quality of raw material has determined effect on property of ceramic. Differences between functional ceramic and traditional ceramic are embodied in the control of raw material, grain size and distribution, reacting activity, crystalline and cost. The common tungsten trioxide target producing methods are solid phase method, vapor phase method and liquid phase method.

【Chinatungsten】Tungsten Carbide Rings Pros and Cons