Bharucha, J. - (1.) The appellants (original writ petitioners) import asbestos fibre and pay Customs duty thereon under entry 25.01.32, which reads :"Mineral substances not elsewhere specified . . . . . . . . . . . . . . . . . . (1 ) XX XX XX (2) Asbestos raw including fibre 40% XX XX XX" There is no dispute in regard to the levy of Customs duty. The dispute is in regard to the levy on the imported asbestos fibre of additional duty under Section 3(1) of the Customs Tariff Act. 1975, which is quoted hereinafter. The appellant in Civil Appeal No. 1354 of 1980 also mines asbestos in India and is made liable to pay excise duty thereon under Tariff item 22F, which reads thus : "Item Description of goods Rate of duty No. 22F Mineral Fibres and Yarn, and manufactures therefrom in or in Fifteen per cent ad relation to the manufacture of which any process is ordinarily valorem carried on with the aid of power. Explanation : "Mineral fibres and yarn, and manufactures therefrom" shall be deemed to include : (i) glass fibre and yarn including glass tissues and glasswool; (ii) asbestos fibre and yarn; (iii) any other mineral fibre or yarn, whether continuous or otherwise such as slagwool and rock wool; and (iv) manufactures containing other than asbestos cement products." This levy is also disputed. By the common judgment under appeal, the Delhi High Court dismissed the writ petitions.
(2.) The constitutionality of the imposition of excise duty on asbestos fibre is not now disputed.
(3.) What asbestos is and how it is recovered is set out in the judgment under appeal, and it is not faulted on this account. This is what it says : Major producers of asbestos are Canda and U.S.S.R. Asbestos is defined as general name for the useful fibrous varieties of a number of rock forming minerals. The value of asbestos ensues from the incombustible nature of the products fabricated from the various grades of mineral fibres. (Vide Me. Graw Hill Encyclopaedia of Science and Technology. Vol. 1 (1977) page 618). Most absestos fibres occur in small cracks in massive rocks and are difficult to recover e.g. a large cubic open pit mine handles approximately 16 tons of ore. 8 tons of waste ore and 23 tons of over-burden to produce a single ton of asbestos. To mine chrysotile, the ore is first blasted loose. The larger asbestos seams i.e. those that are at least 9.5 mm wide are picked from the ore after blasting and adhering rock is removed with a pick. The resulting chuncks of ore called crudes. Which may contain as much as 80% water, ore then dried in preparation for the next stage separation into fibres. Fibre separation is accomplished mainly by a series of shaking screens, special separators called cyclones, and additional crushers or fibrizers. At each shaking screen the liberated fibres are sucked off by an airstream and collected for grading and packaging. The larger pieces of ore which are retained by the screen are recycled for further crushing. Smaller pieces, which pass through the screen and are called throughs are sent to the next crushing or fiberizing sequence. The extremely small pieces that fall through the screens following the final fiberizer are discarded. (Vide Encyclopaedia Americans Vol. II (1970) Page 427, 428). Similarly the Encyclopaedia of Natural Chemical analysis, Vol. II gives the processing of asbestos fibre as follows :- "Asbestos fibre is recovered by open pit or underground mining operations. In the open pit operation the ore is taken from the top of the deposit and in underground method, the ore is removed from the bottom of the deposit. One imported method used in underground mining is known as block carving. In this method, a large block of ore is loosened in such a way that it breaks down from its own weight. The ore is extracted through a network of tunnels and carried to primary crushers which break up the large rock chunks into fragments. The crushed ore falls into bins and then undergoes further crushing and drying prior to processing at the mill. The milling operations are complicated but consist of separating the fibres from the rock, in the mill the rock is crushed more finely and passes ores through vibrating screens which roughly separate the loose fibre from the rock. Powerful hoods, which operate much like vaccum cleaners, lift the loose fibre leaving the heavier rock. This operation is repeated until the separation is complete and only waste rock remains. The separated fibres are then cleared and carefully graded according to length. Grading is done according to rigid industrial specifications. BRUSSELS NOMENCLATURE defines asbestos as follows : "25.23 - ASBESTOS : Asbestos is a natural mineral substance produced by the decomposition of certain rocks. It has a very characteristic fibrous texture: It is sometimes, silky in appearance and the colour varies greatly, being usually white, but sometimes grey, greenish, blue or dark brown. Its main property is its resistance to fire and acids. The heading applies to crude asbestos in rock form, to raw, beaten or washed fibres. Whether graded to length or not, to asbestos in flakes or powder and also to asbestos waste. The heading excludes fibre which has been further processed graded, dyed etc.) and finished articles of asbestos (heading 68.13)" The process by which the asbestos fibre is obtained is more or less as follows :- The petitioners extract asbestos rock from the mine which is in the shape of large boulders. This asbestos rock is put into jaw crushers and is made into small size of about 20-40 mm. These further rocks of 20-40 mm size are still subject to further reduction in a hammer mill, the purpose of which is to reduce the rock to a stage so that the fibre could be taken away from rock in which it is embedded. The asbestos fibre is found on the rocks which contain thin layer of the fibre of about an inch in length of a piece of rock about the size of a cricket ball. The petitioners have obtained permission from the Collector of Central Excise. Patna as communicated by Assistant Collector dated December 14, 1977 to remove in bond semi finished goods under Rule 56 (b) from the mining place at Roro to the factory at Hyderbad for further processing after the pieces of rock are brought to Hyderabad they are crushed to smaller size with the aid of power and the resultant is subject to series of screening surfaces so that the asbestos fibre which is very much lighter is removed and seperated from the dust and the grit. The fibre, however, still contains rock particles and spicules. The fibre is then pressed through a Hwrricane Hill where rapidly rotating rotors pulverise the stones and spiicules without damaging the fibre. It is in this process that ultimately the asbestos fibre free of all dust and stone particles is produced." ;