Experimental Study on Solid-Phase Reduction Reaction of Calcium Tungstate by Silicon

In order to study the solid-phase reduction process of CaWO₄ and Si at low temperature during steelmaking process by direct alloying,the thermo-analysis experiments on CaWO₄ and Si powder mixture have been carried out by using differential thermal analyzer with constant heating rate 10℃/min,the reaction products and reaction ratio of CaWO₄ and Si pellets at 1 400℃for 30 min are analyzed by high temperature furnace constant temperature test and combined with melting point measure test the behavior of physical change of pellets in heating process is analyzed.Experimental results show that the reduction reactions of CaWO₄ and Si occurred at less than 1 400℃are all solid-phase reaction,the products of reaction are W, WSi₂, W₅Si₃, Ca3(Si₃O₉) and SiO₂,the reduction ratio of CaWO₄ pellets at 1400℃for 30 min is up to 93.41%,and during solid-phase reaction process the CaO could not increase the reaction rate;with condition of constant heating rate at less than 1 400℃,the apparent reaction of CaWO₄ and Si conforms to Avarami-Erofeev equation,the mechanism of reaction is random nucleation and subsequent growth,and the apparent reaction dynamical equation is da/dt = 11.68e～(-51.75×10～3/RT)·4(1-α)[-ln(1-α)]～(3/4).

 

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

• < Prev
• Next >