20. Extracite briquettes, manufactured by Sophia-Jacoba Handelsgesellschaft mbH at Hückelhoven, Germany, which—
(a)comprise anthracite duff (as to approximately 95.5% of the total weight) and ammonium lignosulphonate lye as binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 260°C;
(c)are cushion-shaped briquettes with a silvery appearance and are marked with the letters “S” and “J”;
(d)have an average weight of 40 grams per briquette; and
(e)have a sulphur content of approximately 1.2% of the total weight.