ADVANCED PROCESS CONTROL IN COBALT STRIPPING

摘要

The current work presents an advanced process control application, based on Fuzzy technology, in a cobalt stripping process in order to control the cobalt and zinc concentrations. The main purpose of the process is the cobalt stripping from the organic solution and there is an optimum pH which gives the best cobalt transference to the aqueous solution. If the pH is high, the cobalt won’t be transferred within the solutions and if the pH is low, the zinc concentration passes the maximum limit in aqueous solution. Since there are three critical points to be controlled, it is difficult to stabilize the operation. The software used does not require phenomenological knowledge to control the pHs. By anticipating production variances, the process variability was reduced by up to 40% and the cobalt concentration was reduced in 35ppm, which represented an income increase of about R$1.000.000/year or U$ 250.000/year.