comprise anthracite fines (as to approximately 50 to 75% of the total weight), petroleum coke (as to approximately 20 to 45% of the total weight), bituminous coal (as to approximately 5 to 17% of the total weight) and an organic binder (as to the remaining weight);

were manufactured from those constituents by a process involving roll-pressing;

are pillow-shaped briquettes with two parallel indented lines running latitudinally around the briquette;

have an average weight of 130 grams per briquette; and

have a sulphur content not exceeding 2% of the total weight.