comprise bituminous coal (as to approximately 10 to 15% of the total weight), petroleum coke (as to approximately 70 to 80% of the total weight), and anthracite duff and starch binder (as to the remaining weight);

were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 260 °C;

are unmarked pillow-shaped briquettes that are approximately 84 millimetres in length, 38 millimetres in width and 62 millimetres in height;

have an average weight of 118 grams per briquette; and

have a sulphur content not exceeding 1.9% of the total weight.