In order to study the solid-phase reduction process of CaW0

4

and Si at low temperature during steelmaking process by direct alloying

the thermo-analysis experiments on CaWO

4

and Si powder mixture have been carried out by using differential thermal analyzer with constant heating rate 10 T/min

the reaction products and reaction ratio of CaWO

2

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 CaW04 and Si occurred at less than 1 400℃ are all solid-phase reaction

the products of reaction are W

WSi

2

W

5

Si

3

Ca

3

( Si

3

0

9

) and SiO

2

the reduction ratio of CaW0

4

pellets at 1 400 °C 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 CaW0

4

and Si conforms to Avarami -Erofeev equation

the mech-anism of reaction is random nucleation and subsequent growth

and the apparent reaction dynamical equation is da/dt = 11.68e

-51.75x103/RT.

4( 1 - a) [ - ln( 1 - a)

]

3/4