Reduced puffing needle coke from coal tar distillate
View Patent ↗A reduced puffing needle coke is formed, which includes a reduced nitrogen content within the coke so that the coke particles do not experience as much puffing during the formation of graphitized carbon articles produced from such coke upon heating to graphitization temperatures.
1. A calcined reduced puffing needle coke derived from coal tar distillate comprising needle coke with a nitrogen content of less than about 0.2% nitrogen and a coefficient of thermal expansion below about 0.20 cm/cm° *10 −6 .
2. The needle coke of claim 1 , which has a coefficient of thermal expansion below about 0.125 cm/cm° C*10 −6 .
3. The needle coke of claim 2 , which has a coefficient of thermal expansion below about 0.10 cm/cm° C*10−6.
4. The needle coke of claim 1 , which has a nitrogen content of less than about 0.03% by weight and a sulfur content of less than about 1.0% by weight.
5. A graphite electrode formed using a calcined reduced puffing needle coke derived from coal tar comprising needle coke with a nitrogen content of less than about 0.4% nitrogen and a coefficient of thermal expansion below about 0.20 cm/cm° C*10 −6 .
6. The graphite electrode of claim 5 , formed using a calcined reduced puffing needle coke derived from coal tar comprising needle coke with a nitrogen content of less than about 0.4% nitrogen and needle cokes not derived from coal tar comprising needle coke with a nitrogen content of less than about 0.4% nitrogen.