Carbon spheres in metallurgical coke

Carbon spheres (CSs) of 1–15 μm in size were found in metallurgical coke for the first time as by-products of large-scale industrial process. CSs form a dense cover on the surface of pores and occur as separate aggregates varying in size and shape. Their formation may be associated with the circulation of coke oven gas in the contact area between the coke and the refractory silica bricks of the oven. If the amount of CSs in metallurgical coke proves substantial, the evaluation of its properties (reactivity, strength) should be re-considered.