In an open-hearth furnace, 2.5 tons of steel scrap was melted, taken at a temperature of 25 degrees.

In an open-hearth furnace, 2.5 tons of steel scrap was melted, taken at a temperature of 25 degrees. How much heat was required for this?

Task data: m (weight of steel scrap taken) = 2.5 t (2500 kg); t0 (temperature of scrap before melting in open-hearth furnace) = 25 ºС.

Reference values: Сс (specific heat capacity of steel) = 500 J / (kg * K); tmelt (average temperature of the beginning of steel melting) = 1400 ºС; λ (specific heat of melting of steel) = 0.84 * 10 ^ 5 J / kg.

Heat for melting steel scrap in an open-hearth furnace: Q = Cc * m * (tmelt – t) + λ * m.

Calculation: Q = 500 * 2500 * (1400 – 25) + 0.84 * 10 ^ 5 * 2500 = 1 928 750 000 J ≈ 1.93 GJ.