32. Homefire briquettes, manufactured by Coal Products Limited at Immingham Briquetting Works, Immingham, North East Lincolnshire, which—E+W+S
(a)comprise anthracite fines (as to approximately 40 to 70% of the total weight), petroleum coke (as to approximately 20 to 45% of the total weight), char (as to approximately 0 to 10% of the total weight), bituminous coal (as to approximately 5 to 30% of the total weight) and an organic binder or a molasses and phosphoric acid binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing;
(c)have a volatile matter content in the finished briquette of neither less than 9 nor more than 15% of the total weight on a dry basis;
(d)are unmarked hexagonal briquettes;
(e)have an average weight of 140 grams per briquette; and
(f)have a sulphur content not exceeding 2% of the total weight.