Comparison of NKK and CANMET analyses from CCRA-NKK coal and coke exchange

This report compares results obtained by Nippon Kokan Keihin K. (NKK) and CANMET on round robin coal and coke samples exchanged between NKK and the Canadian Carbonization Research Association. The two coal samples were carbonized in CANMET and NKK test ovens. Analyses were made by NKK and CANMET on the coal blends, industrial cokes and two of the test-oven cokes. Results from coal analyses showed that CANMET'S proximate, Gieseler fluidity and inert content varied from those given by NKK. Coke analyses showed that size distribution and chemical measurements were similar for the two laboratories. The JIS drum indices were similar for both laboratories but UNMET results were consistently larger by about 0.25%-0.7%. Results from NKK and CANMET laboratories for ASTM stability and hardness factors were related but CANMET results were 1 to 3 units higher than those of NKK. Both laboratories generally obtained similar CSR and CRI values but micro-strength indices were considerably different. Comparison of cokes from NKK and CANMET test ovens indicated JIS drum indices were comparable but slightly lower than industrial values. ASTM coke stability and hardness, ASG, and CSR results from the NKK oven were lower than results from CANMET test ovens.