Year: 2015
Type: dissertation
Abstract: The main purpose of the base metal refinery (BMR) as operated by Lonmin at their Western Platinum Ltd BMR, is to remove base metals -such as copper and nickel -from a platinum group metal (PGM) containing matte.The leaching processes in which this is done pose several challenges to the control of the process.The most significant of these is the slow dynamics of the process, due to large process units, as well as the continuously changing composition of the first stage leach residue, which is not measured on-line.This is aggravated by the fact that the exact leaching kinetics (and therefore the effect of the disturbances) are not understood well fundamentally.The slow process dynamics mean that controllers cannot be tuned aggressively, resulting in slow control action.The large residence times and off-line composition analyses of major controlled variables also mean that the effects of operator set point changes are visible only the following day, often by a different shift of operators.Dorfling (2012) recently developed a fundamental dynamic model of the pressure leach process at Lonmin"s BMR.This dynamic model incorporates 21 chemical reactions, as well as mass and energy balances, into a system of 217 differential equations.The model provides a simulation framework within which improved control strategies can be investigated.
Author: Pieter Daniel Knoblauch
Language: English
Subfield: Control and Systems Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2152132613