FIG. 1 demonstrates the effect of temperature on the oxidation rate of ferrotungsten. In FIG. 1, the percent weight gain of the ferrotungsten (FeW) at different temperatures is plotted against time. The data in FIG. 1 reveal that there is a significant increase in the oxidation rate of ferrotungsten above about 900° C. Unfortunately, the increase rate of oxidation at higher temperatures becomes limited by the ability of the calciner to effectively operate at the higher temperatures while handling production quantities of ferrotungsten. For a typical commercial calciner, the calciner is normally limited to operating at temperatures less than about 1000° C. because the calciner tube must be made out of alloys which have sufficient strength to handle the heavy and abrasive ferrotungsten. This excludes higher temperature tube materials such as alumina and silicon carbide which do not possess the needed strength. Therefore, to increase the rate of oxidation further, it is necessary to either decrease the particle size of the ferrotungsten being calcined or increase the oxygen content of the calciner atmosphere. The effects of these parameters on the oxidation rate of ferrotungsten are described below.
FIG. 1 is a graphical representation of the effect of temperature on the oxidation of ferrotungsten.
Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn