Recycling of aluminum: development of technological innovations

• Grant number: 99/06282-9
• Support Opportunities: Research Grants - Research Partnership for Technological Innovation - PITE
• Duration: July 01, 2000 - May 31, 2005
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: Antonio Carlos da Cruz
• Grantee: Antonio Carlos da Cruz
• Host Institution: Instituto de Pesquisas Tecnológicas S/A (IPT). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil
• Host Company: Associação Brasileira de Alumínio (ABAL)
• City: São Paulo

Abstract

The conventional process for the recovery of aluminum is based on the heating of the recovery furnaces by means of air/oil combustion. To increase the metallurgical yield of this process, there is an addition of salts (NACI and KCI) to the load, in a proportion of between 10 and 40 kg for each 100 kg of residue processed. These salts are easily lixiviated by water, and, for this reason, they call for the disposal of the residue from the process (black sludge) in industrial landfills. Due to its high cost, this practice is not always observed, above all by small businesses from the sector. In addition, the conventional process is highly pollutant, due to the presence of salt vapors in the exhaust gases. As they are corrosive, these vapors cause the premature wear of the gas cleaning equipment and a consequent increase in processing costs. The project’s main objective was to research and develop a clean (without the use of salts) process of its own for recycling aluminum. The project made use of the previous experience of its proponents, in the development of similar equipment, applied to the remelting of aluminum refuse (IPT), and in the study for optimization of recycling processes (Epusp) and included the comparative study of two techniques for the heating of the recovery furnace: heating with an electric arc (plasma) and by oxy-gas. Besides the recycling of aluminum, the project pursued the prospective study of the reuse of the solid residue generated by the process, as raw material for refractory products, abrasives and/or white ceramics. The project involved the assembly of a recovery furnace with a nominal capacity of 100 kg/h, the operation of this equipment in the processing of waste from different origins with two alternative sources of energy; the analytic monitoring of the process, with a view to studying the variables in the process and the assessment of the performance of each alternative. The project also provided for a technical/economic study to be carried out, aiming to scale the equipment for the capacity needed to meet the industrial demand for the treatment of these residues. (AU)

Filed patent(s) as a result of this research project