Molybdenum electrodes in electric glass melting applications are as following:
1. Platinum Drawing Furnace
Glass fiber is an important building materials and electrical materials. Traditional production method for glass is using Pt-7Rh alloy as crucible with fibers a large current to make crucible has high temperature so the glass can melt. Besides, each crucible needs 3kg Pt-7Rh alloy. Currently, estimate the cost according to 3000 on-line crucible there will be need 9t platinum and rhodium alloy estimates, rather than about 10 billion RMB. In the production, the annual platinum consume up to 1500kg. Thus, using whole platinum drawing crucible is not suit for China’s national conditions. According to the characteristics of glass electric melting, if using molybdenum electrode and natural fireproofing as material to make platinum drawing furnace, so it only need 6009kg R-7Rh. Therefore, 3000 Crucible, it may use less platinum and rhodium alloy 7000kg, net save alloy about 1400kg, worth more than 10 billion RMB. At present, using molybdenum electrode to replace platinum drawing furnace is the only way for produce glass fiber, and its effectiveness same to the full platinum crucible.
2. GRC Fiber
Glass fiber reinforced cement (GRC) composites are new building materials. It requires glass fiber reinforced has good compatibility and corrosion stability with cement. The glass fibers contain 10%~20% ZrO, its melting temperature up to 1500 ℃, so it must be produced by electric melting method. To produce such fibers electric melting electrodes of molybdenum has developed a special ingredient and special structure giant electrodes, which has effective conducting area 2800~5000cm can enter 170~300kV•A. Besides, its life more than two years can meet the GRC fiber production. Its cost is only 15% of similar imported products.
3. Molybdenum Electrodes Using in Aluminium Silicate Fiber Electric Furnace
Aluminum silicate fiber felt is high temperature insulation material, the fiber's melting temperature up to 1700~1800℃, can only be produced by electric melting method. Production technology was originally introduced but now it is domestically. The development electrodes have been completely replaced by imported products, service life long than similar imported products and the cost only 60% to imported products cost.
4. Molybdenum Electrodes Using in Ophthalmic Lens Production
In glass products, the lens has highest strict requirements for transparency and uniformity control of lens are extreme strict which there must be no pollution coloration and melting temperature only allowing fluctuations ±2℃. Therefore using conventional flame furnace only produce low profile lens, only use electric melting method to produce high-grade lenses. Full electric melting method in China is still blank and the key technology of it is the electrode design and production. In 1988, some researcher had to develop large plate electrodes, after special treatment using in electric melting furnace (power about 150kw) which is for the lenses production, working life more than one year. All investment rather only 15% to introduce of hardware and software cost. Fully rely on domestic technology to produce high-quality lenses.