1. In order to appreciate the controversy involved in this writ petition few facts need mention. The petitioner is a Government company. Its 'Malajkhand Copper Mining & Ore Concentration Project' is situate in district Balaghat (M.P.), where the petitioner is engaged in extraction of copper ore by open cast mining process. It is averred in the writ petition that after drilling and blasting the ore in the open pit mine, the ore in the form of boulders is transported to the Primary Crusher (situated at a distance of 2.53 km from the mine), where it is crushed into pebbles/pieces. Such crushed ore is then carried on a conveyor to a Secondary Crusher (situated at about 5 km from the mine) for further crushing into smaller pebbles. The small pieces/pebbles are then carried by a conveyer to the Concentrator Plant (situated at 5.5 km from the mine). In the Concentrator Plant, the ore is milled into powder in the Ball Mills. Such powder mixed with water is carried in the form of slurry to floatation cells. In the floatation cells, the slurry is subjected to froth Floatation Process and the copper concentrate is removed and dried in vacuum dried and stored in Concentrate Storage Sheds. The waste paste known as 'tailing' is pumped into a Tailing Dam through tailing pumps. The tailing pumps are at a distance of 8 km from the mine. Large quantity of water is required for Concentrator Plant for being used in milling. Water is also required for the factory township. The required water is pumped from the mines through pumps located at an Intake Well (situated at a distance of 10 km from the mine).

2. The petitioner submits that as per the facts set forth in the petition, the manufacture of copper concentrate consists of two distinct parts/activities. First is mining, that is drilling, blasting and collecting of ore. This activity is carried on at mine pit. This activity is carried on in the mine area registered under the Mines Act. The second part/activity comprises processing of the ore so mined. This second part/activity is carried on at the Primary Crusher, Secondary Crusher and Concentrator Plant. The processing (manufacturing) part must be treated to be an activity separate and distinct from mining as such processing is carried out in the factory area. The Primary Crusher, the Secondary Crusher, the Ball Mill, the Concentrator Plant, the Tailing Pumps, the Intake Well and the Water Treatment Plant are situated away from the mine, at distances varying 2.5 KM to 10 KM and are registered separately as a 'Factory' under the provisions of Factories Act, 1948. Admittedly, the open pit mine (mining area) and the processing plants/machineries (Factory area) are all situated in a large tract of land taken on mining lease from the State Government.

3. Section 3 of the M.P. Electricity Duty Act, 1949 (hereinafter referred to as 'the Act') which provides for levy of electricity duty on sale or consumption of electrical energy, was amended by M.P. Act No.21 of 1986. Explanation (b) to Part B of Section 3 of the Act defines the term ‘mine’ to mean a mine to which the Mines Act 1952 applies and includes the premises or machinery situated in or ‘adjacent’ to a mine and used for crushing, processing, treating and transporting the mineral.

4. The petitioner being aggrieved by the extended definition of mine, the effect of which is to include the processing apart from mining and prescription of higher rate of duty for mine i.e. for composite activities of mine and processing, filed a writ petition, namely, M.P. 2821/1988. The challenge to the extended definition of mine in explanation (b) to Part B of Section 3 was made on the ground that it results in dissimilar treatment to similar (processing) activity by prescribing different rates for different factories and the definition has the effect of categorising the factories registered under the Factory Act, and carrying on the same activity of processing, treating and transport the minerals, into two