The gross energy requirement, to reduce a very large feed of coal to such a size that 80% of the product passes through a 100 µm screen, is 13 kWh per ton of feed. In a process, 250 tons h⁻¹ of coal is crushed. 80% of the feed passes through an opening of 100 mm, and 80% of the product is to pass through an opening of 25 mm. According to Bond's law, which one of the following is the power consumption (in kW)?

Question

Accepted Answer

The correct answer is D, 102.7. GATE 2026 official key: (D). Bond's work index from the given data is Wi = 13. Applying Bond's law to F80=100 mm, P80=25 mm gives E ≈ 0.411 kWh/ton; Power = 0.411 × 250 ≈ 102.7 kW.