Principles of improvement the energy efficiency in pyrometallurgy of copper: utilization the secondary heat energy of intermediate products

Abstract

Having in mind that the energy is more and more expensive and that the natural energy resources are smaller and smaller, this research presents a contribution to the use of renewable thermoenergetic resources in terms of improving the economy and ecology in the pyrometallurgical copper production. Pyrometallurgical copper production is a big consumer of energy resources of all kinds. A large part of invested energy is used in the metallurgical process. The process products are holders of large energy amount that is lost uncontrollably in the environment, thereby affecting adversely the economic and environmental effects. The available heat energy of gas products and flying dust of fluosolid reactor, technically usable in the Power Plant, taking into account the "excess" of the process heat, has value 874.971 kJ/kg dry concentrate. Technically usable the heat flux for the reactor No. 1, is 9.79 MWh, and minimum heat flux is 5.319 MWh. In the sulphuric acid production, that uses the gaseous products of roasting and converting processes in Smelter, the low temperature secondary heating energy is realized in quantity of 1.348 MWth/t monohydrate ( or 336.8 kWth/(1000 m(3) n) gaseous products). For designed capacity of Sulphuric Acid Plant No. 2, that is in exploitation ( in farther text K-2) in Bor, the existing quantity of secondary ( waste) heating energy is 24.830 MWt. This paper presents the results of research the renewable thermoenergetic resources from metallurgical products. Using the comparative method, the consumption of energy resources is determined in the modem technological processes and standard pyrometallurgical process of copper production in Bor ( Serbia) and, based on the heat balance, the amount of the secondary energy is defined and the method of its evaluation is proposed.