Improving of Mixing Efficiency in a Stirred Reactor for Lead Recycling Using Computer Simulation

Abstract

Recycling is helping to reduce environmental risks and damages. Liquid lead is recovered from batteries in stirred batch reactors. Nevertheless it is necessary to establish parameters to evaluate mixing performance in order to make more efficient the industrial practices. Then this work is dedicated to simulate fluid hydrodynamics in a lead stirred reactor by monitoring the distribution of an injected tracer to find the best injection point. Different injected points have been evaluated monitoring the tracer concentration on a group of points inside the batch to verify mixing. The tracer is assumed as ideal (with the same physical properties than lead). The reactor is a batch with two geometrical sections one cylindrical body and a semispherical on the bottom. The impeller used to promote lead stirring is a shaft with four flat blades. The tracer concentration on the monitoring points is averaged to evaluate the efficiency all around the reactor. Finally invariability of tracer concentration on the monitoring points is adopted as the criterion to evaluate mixing.