Why Use Tungsten Accelerator in Carbon & Sulfur Analyzer
Tungsten accelerator as a normal additives in Carbon&Sulfur Analyzer, its features are:
1. Tungsten is the most difficult metal to melt, its melting point is 3380℃. The temperature of electronic arc can melt tungsten, tungsten wire commonly used in light bulbs.
2. The oxidation of tungsten is when the temperature of tungsten particles is higher than 650℃,oxygen will begin to oxidize and emit a lot of heat.
W3/2O2 =WO3, ∆H=-840KJ*mol-1
3. Tungsten trioxide is an acidic oxide, its production is conducive to the release of CO2 and SO2 , with a melting point of 1473℃, and boiling point is greater than 1750℃.
WO3 has an important feature, the temperature is above 900℃, there is significant sublimation, and some WO3 volatilizes. Due to the escape of WO3, the diffusion rate of carbon and sulfur is increased, so that carbon and sulfur in the sample are fully oxidized. Volatile WO3 is transformed into solid phase again at 700~800℃, covering the Fe2 remaining in the pipeline, preventing the catalytic conversion of SO2 to SO3. It prevents the pipeline from adsorbing sulfur, thereby ensuring the reliability of carbon and sulfur analysis results. In addition, tungsten has a low blank value, which can be used for the determination of low carbon and low sulfur. Therefore, tungsten particles accelerator is widely used in high-frequency furnace combustion.
4. The particle size of the additive tungsten is best controlled between 0.84~0.42mm, and the porosity is about 15%. It needs a dense and smooth surface, which can prevent the oxygen flow from blowing, and can quickly oxidize and burn, and can also reduce surface adsorption.