CPC Testing and Relationship Between Coke and Anode Physical Properties

Rain Carbon completed its 20th global CPC round robin (RR) in 2016 with five CPC samples covering a wide range of chemical and physical properties as well as both rotary kiln and shaft calcining technologies. Twenty-three labs participated in the RR and the paper summarizes repeatability and reproducibility data for the different test methods. Particular emphasis was given to bulk density testing. Pilot anodes were prepared with each coke to examine the relationship between coke bulk density, anode density and other anode physical properties. The study generated some interesting findings with respect to bulk densities measured on naturally occurring coke particles. As coke particle size increases, particle shape has a greater influence on the bulk density result. An alternative envelope density test gives a more reliable indicator of anode density. The paper also provides an update on a new ASTM bulk density test being developed.