39. Newburn briquettes, manufactured by ECL Mineral Processing Limited of Newfield Works, Newfield, Bishop Auckland which—
(a)comprise petroleum coke (as to approximately 56 to 57% of the total weight), anthracite (as to approximately 37 to 38% of the total weight), and a dry powder binder (as to the remaining weight);
(b)were manufactured from those constituents by a cold cure process using roller press;
(c)are unmarked pillow shape briquettes 70mm x 62mm x 42mm;
(d)have an average weight of 110 g per briquette; and
(e)have a sulphur content not exceeding 2% of the total weight.