1) Preparation of doped tungsten powder: put the original tungsten (WO2.9) powder and the mixed solution of H2SiO3 and KOH containing SIO2: 0.2~0.6wt% and K2O: 0.2~0.6wt% and AI (NO3) 3 containing AI2O3: 0.02~0.1wt% into the mixer, mix them at 50~60 ° C for 3~5 hours, dry them at 100~200 ° C for 3~6 hours, and obtain doped blue tungsten powder;
2) Reduction treatment: put the doped tungsten powder in a boat at 500~950 ° C and hydrogen atmosphere for reduction treatment for 8~12 hours, and pass through 100~200 mesh sieve after cooling to obtain doped tungsten powder;
3) Pickling: First, dilute hydrochloric acid with a concentration of 3-6wt% is used to pickle the doped tungsten powder for 30-60 minutes, then the supernatant is removed, and hydrofluoric acid with a concentration of 3-6wt% is added to wash the powder until the Si content is s250ppm and the AI content is ≤ 30ppm. Then, the powder is vacuum dried at a temperature of 70-150 ° C for no less than 10 hours. After drying, it is dispersed and impurity removed through a 160~200 mesh sieve;
4) Compaction: press the powder obtained from 3 treatments into doped tungsten billets under the pressure of 150~250MPa;
5) Pre sintering: the pressed blank is placed in a boat vessel and sintered for 30~60 minutes under hydrogen atmosphere and 1100~1400 ° C temperature
6) Vertical melting sintering: place the pre sintered billets in a vertical furnace, sinter them in a hydrogen atmosphere and 70~92% of the current intensity of the fusing current for 10~25 minutes, and then cool them in the furnace to obtain non compact potassium tungsten bars;
7) Indirect sintering: place the tungsten bars obtained in the 6 processes in the medium frequency furnace or tungsten rod furnace, and sinter them for 2~6 hours in hydrogen atmosphere and at the temperature of 2000~2300 ° C. After cooling in the furnace, the target metal tungsten bars containing potassium can be obtained.
Amanda
Company: Baoji Dynamic Trading Co., Ltd
Country:China
Add:Baoti road,Jintai,Baoji city,Shaanxi,China
Cel/Whatsapp :+86 18309262795
Email:annie@jmyunti.com
Website:www.jm-titanium.com
