The study is based on technical results conducted from October 2015 to January 2016 . Plant physical performance was measured and Metallurgical data was collected. Phase disengagement time in the E1 Mixer was measured S1 were also wi th the mixer operating in organic operating in organic continuous mode. continuous mode; E2 a nd Visual organic in aqueous entrainment appeared to be high in the E1 and E2 aqueous launders. Organic bed depths are at lower levels in the settlers. Crud levels in extractions settlers were high and a d ispersion band was observed in settlers . this led to the reconfiguration of the solvent extraction circuit to minimize the loss of the organic phase. As a result, Boss Mining would like to achieve an annual output of 100,000 tons of cathodes, so a mathemat ical model based on a multi objective approach is proposed Keywords: Optimization; Multiobjective; Integer pro gramming; Goal.
Table of Contents
1. General information on silicate minerals
1.1 Dissolution of silicates
1.1.1 Action of acids on silica
1.2 Kinetics of dissolution of silicate minerals
1.3 Thermodynamic aspect
1.3.1 Potential - pH diagram of the Cu - H2O system and Si-O-H2O at 25 ° C.
1.4 Leaching techniques
1.4.1 Heap leaching
1.5 Contaminants from aqueous phase to copper solvent extraction
1.6 Effects of colloidal silica on solvent extraction
1.6.1 Behaviour and mode of locomotion of colloidal silica in the SX-EW circuit
1.6.2 Brief overview of colloidal silica in the Heap Leaching -SX-EW circuit of Boss Mining
1.6.3 Modes of removal of colloidal silica
2. Presentation and analysis of the results
2.1. Evaluation of the loss of the organic phase in the Boss Mining SX Plant circuit
2.2. Metallurgical performance comparison between 2E, 1S and 1W, 2E, 1S
3. Multi objective approaches in the optimisation of Boss Mining Plant
Objectives and Research Themes
The primary objective of this project is to optimize the solvent extraction process at the Boss Mining plant to achieve an annual production target of 100,000 tons of copper cathodes by implementing a multi-objective mathematical model.
- Evaluation of organic phase losses and impurity impacts.
- Comparative analysis of different solvent extraction circuit configurations.
- Formulation of a multi-objective integer programming model.
- Optimization of electrolysis parameters and copper transfer efficiency.
- Mitigation strategies for colloidal silica and crud formation.
Excerpt from the Book
1.6.3 Modes of removal of colloidal silica
A number of articles talking about cruds also talk on the effects of colloidal silica, but provide little information on how to propose a solution to this problem.
Fletcher and Cage, (1985) cited by Miller G. (1994), demonstrated: that for a medium of chloride, the presence of 500 ppm of fluoride is preventive for the precipitation / polymerization of silica even at concentrations of 500 ppm; that it was possible to minimize the effect of the silica, from PLS in the agitated tank leaching circuit, by the addition of the polyglycols or the polyethylene oxide (example of the polyox); this is not yet well revealed for the solutions of dump and heap leaching operations.
According to Cognis 2005, the addition of the coagulating agent in the CCD circuit allows the evacuation of the coagulated silica with the residue;
Neutralization of the colloidal silica charges can be done with CaCO3 between pH 3.5 and 5.0 (Lwandu, 2008);
Cognis 2005, also stated without much specification after laboratory diagnostics that washing PLS with diluent and activated carbon treatment could solve the problems posed by contaminants from the aqueous phase to solvent extraction;
Tshinangi K, (2016) was able to demonstrate that the recommendations proposed by Cognis to the laboratory could eliminate a certain number of contaminants and the pilot plant tests allowed him to propose a reconfiguration of the Luita Boss Mining circuit by inserting a stage washing of PLS solutions with shellsol2325 diluent.
Summary of Chapters
1. General information on silicate minerals: This chapter covers the fundamental chemical behavior of silicates, including dissolution kinetics, thermodynamic stability through Pourbaix diagrams, and various leaching techniques.
2. Presentation and analysis of the results: This section evaluates the current performance of the Boss Mining plant, identifying key issues like organic phase loss and crud formation caused by contaminants, and compares different circuit configurations.
3. Multi objective approaches in the optimisation of Boss Mining Plant: This chapter details the mathematical modeling effort using multi-objective integer programming to maximize copper recovery and production efficiency.
Keywords
Optimization, Multiobjective, Integer programming, Goal, Solvent extraction, Copper, Silicate minerals, Leaching, Colloidal silica, Crud formation, Electrowinning, Metallurgical performance, Boss Mining, Cathodes, Faraday's law.
Frequently Asked Questions
What is the core focus of this study?
The study focuses on optimizing the hydrometallurgical operations at the Boss Mining solvent extraction plant to reach an annual production target of 100,000 tons of copper cathodes.
What are the primary challenges addressed in the research?
The research addresses operational inefficiencies caused by physical and chemical contaminants, specifically colloidal silica, which leads to crud formation, organic phase loss, and slow phase separation.
What is the ultimate goal of the proposed mathematical model?
The goal is to maximize the copper transfer from extraction to stripping and ensure that the total production output meets the 100,000-ton annual requirement by optimizing operational parameters.
Which scientific method is utilized in this work?
The study employs a combination of empirical laboratory and pilot plant testing for performance evaluation, followed by the formulation of a multi-objective integer programming model to optimize system variables.
What does the main body of the work cover?
The main body covers the analysis of silicate dissolution kinetics, empirical evaluations of the existing plant configuration, comparative performance testing of new circuits, and the derivation of optimization constraints.
How would you summarize the work using keywords?
Key terms include Optimization, Multiobjective, Integer programming, Solvent extraction, Copper, Colloidal silica, and Crud formation.
How does the configuration 1W2E2S differ from the old one?
The new configuration (1W2E2S) includes a washing stage that removes contaminants like silica before the first extraction stage, which helps limit the proliferation of cruds throughout the entire circuit.
What role does Faraday's law play in this model?
Faraday's law is used to govern and calculate the theoretical weight of the copper deposited during the electrowinning process, accounting for the coefficient of utilization of the cells.
- Quote paper
- Kapya Tshinangi (Author), 2019, Descriptive modelling and multi approach in the objective optimization of SX-EW. Case study, Munich, GRIN Verlag, https://www.grin.com/document/511871
