Parametrização do moinho autógeno para a produção do óxido de chumbo

Abstract

Despite its wide application in the manufacture of lead-acid batteries, the operation of autogenous mills for the production of lead oxide is generally conducted empirically, which hinders the technical and predictive control of the process due to the complexity of reactive milling. In light of this issue, the present work presents a study on the parameters of an industrial autogenous mill used in the production of lead oxide for battery manufacturing. The objective is to conduct an empirical survey to verify whether the operational ranges practiced are within the expectations of the sector's literature and to determine process variables that are not routinely collected in the factory. The methodology was based on the integration of chemical kinetics with comminution theory, which, coupled with the mass balance, allowed the reactor to be modeled from empirical data. Based on the statistical regression of the data collected in the plant, an apparent activation energy of 20.19 kJ/mol was determined for the oxidation reaction. Furthermore, the study attested that the mill operates with a feed flow rate of 228 kg/h, which corresponds to 84% of its nominal design capacity. It was also verified that the rotation imposed on the mill drum corresponds to 79% of its critical speed of 35.25 rpm, ensuring the ideal elevation of the lead cylinders. The model's equations determined a temperature of 199.2°C as the optimal thermal setpoint for the reactor. Finally, the study concludes that the operational ranges practiced by the reactor align with the literature, and that the surveying of these parameters consolidates the understanding of the process, ensuring efficiency and stability in the production of active masses.