The main aim of rationalizing the energy management of a blast-furnace plant is to save coke. In general practice coke is replaced by injecting cheaper auxiliary fuels (among others hydrocarbon plastic wastes). The paper gives a short account about such attempts carried out so far in some countries. The energy effects of injecting plastic wastes into the blast furnace have been analyzed and compared with the injection of pulverized coal, natural gas and coke-oven gas.