40 УДК 017.536:669.017.11 Обогащение полезных ископаемых Fathi Habashi, Fathi.Habashi@gmn.ulaval.ca Department of Mining, Metallurgical and Materials Engineering, Laval University (Quebec City, Canada) ENERGY ECONOMY IN EXTRACTIVE Осыған орай, энергия көздерін барынша тиімді пайдаланған дұрыс. <...> Fuel, heat, and electricity are costly items in metallurgical processes and should be used with great efficiency to decrease production costs. <...> To this end, the recent trend in metallurgical plants is focussed towards the following goals: increased use of heat recovery systems; increased use of oxygen instead of air; increased use of direct heating systems; improved equipment design; improved process design; improved methods of operation; attempts to economize energy in the aluminum industry. <...> It is important in metallurgical plants to conduct operations involving heat generation and transfer with maximum economy. <...> A metallurgical operation without a waste heat recovery system is intolerable. <...> Recovery of as much as possible of the heat generated during the reaction that would otherwise be wasted improves the heat economy of a reactor. <...> An extensive heat recovery system is also undesirable because it becomes costly, involves extensive piping, and plant space. <...> Direct heat recovery system To improve energy economy, heat from an exhaust fluid is used for preheating the entering fluid. <...> For example, exhaust hot gases from a furnace can be used to preheat the air and/or the fuel (gas or liquid) used in the furnace (pic. 1). <...> The exhaust gas can also be used to preheat the solid charge entering the furnace, e. g., scrap iron before being introduced into the electric furnace. <...> This system is known as direct heat recovery because the quantity of heat leaving the reactor is directly returned in the same reactor in form of preheated material. <...> Equipment used are tube heat exchanger or regenerators. <...> Heat exchangers (pic. 2) can be metallic Горный журнал Казахстана №6’ 2014 Pic. 1. <...> The metallic exchangers are characterized by a high heat transfer coefficient and low gas leakage, but the metal temperature should not be allowed to exceed 1000°C even <...>