What mass of coke will need to be burned to heat 10 tons of cast iron 10 * С (Specific heat of cast iron 540J / kg ** С)

mh = 10 t = 10000 kg.

Δt = 10 ° C.

Cch = 540 J / kg * ° C.

qk = 29.3 * 10 ^ 6 J / kg.

mk -?

When coke is burned, the amount of heat Qk is released, which we express by the formula: Qk = qk * mk, where qk is the specific heat of combustion of coke, mk is the mass of coke that has burned.

To heat cast iron with a mass of mh by Δt, the required amount of heat Qh is expressed by the formula: Qh = Cch * mh * Δt, where Cch is the specific heat capacity of cast iron.

Since there are no heat losses when heating cast iron, then Qc = Qh.

qк * mк = Сч * мч * Δt – heat balance equation.

mk = Mp * mh * Δt / qk.

mk = 540 J / kg * ° C * 10000 kg * 10 ° C / 29.3 * 10 ^ 6 J / kg = 1.84 kg.

Answer: to heat a cast iron, it is necessary to burn coke mk = 1.84 kg.