Heat generation model in the milling process of the Tantalum mineral in the ball mill

Abstract

Tantalum is a rare metal with many application in the electronic industry. This metal is less abundant in the world than gold. Large quantities of energy are required for its extraction. OPTIMORE is a project funded by European Union, whose primary objective is to optimize the processes of the exploitation of Tantalum and Tungsten. The grinding may represents up to 50% of the direct operating cost in a mineral processing plant due to the fact that comminution devices operate inefficiently (4-8%) [2]. 80% of the energy supplied to milling is lost as heat, sound and vibrations. This work is part of the OPTIMORE project and it focuses on the characterization of the heat generation of Tantalum ore during fracture by direct impact.Moreover quantify the heat energy loss to the environment during the grinding process of the ball mill. Furthermore, the density (2313kg/m3) and specific heat (853 J/kgK) of ore from Penolta mine were experimentally found. In addition a temperature increase of 5.9ºC to 7.3ºC after the fracturing process was observed. Then a numerical model was implemented to calculate the temperature distribution through the mill wall. Three possible combinations of heat transfer coefficients (a, b, c) were analyzed. Finally, the models with coefficients a and c provided the best results in agreement with the experimental data.