Systematic comparison of the effectiveness of water treatment processes
This project is based on the hypothesis that existing processes for treatment of wastewater streams are not necessarily the most effective, partly because both the range of contaminants and treatment methods is very broad. This project is focussed on testing this hypothesis by modelling (on a single simulation platform) a wide range of proven water treatment technologies, combining these into both existing and new processes, and performing multi-criteria evaluations and comparisons of these processes (also using the available tools on the simulation platform).
Antisolvent Crystallization of Rare Earth Sulphates Using a Fluidised Bed Reactor
The global supply vulnerability of rare earth elements (REE) is driving the need for innovative technologies to recover these vital resources. These metals are used for advanced improvements in products such as batteries, magnets and catalysts. Currently, hydrometallurgical processes lack selective and efficient REE recovery. This work focuses on the development of an antisolvent crystallization process for the recovery of REE sulphates from sulphuric acid leach liquors.
Investigating Multiple Steady States in Eutectic Freeze Crystallization
Eutectic Freeze Crystallization (EFC) is used as a wastewater treatment process for industrial brines to recover water and salts. The interaction of these two transport processes depends on the operating conditions of the crystallizer and is so complex that multiple stay states could occur if the initial operating conditions are different. The aim of this study is to understand how the initial ice seed loading affects the steady state conditions of a Na2SO4-water EFC system.
Gypsum Seeding to Prevent Scale Formation and Improve Separation Efficiency
Eutectic Freeze Crystallization (EFC) is a novel technology in which a brine solution is cooled to a temperature below its eutectic point resulting in the co‑crystallization of ice and salt. Calcium sulphate dihydrate (gypsum) scaling on the surfaces of crystallizers has been identified as a problem in the treatment of calcium sulphate-rich brines using EFC. This study seeks to utilise seeding as a method to enhance gypsum crystallization in the bulk solution and thus reduce scaling on the crystalliser walls.
Eutectic Freeze Crystallization Operational Variables effects on Products Yield and Purity
Eutectic Freeze Crystallization (EFC) is a novel and cost-effective separation technique for industrial brines. This process operates by simultaneous crystallization of ice and salt under sub-eutectic conditions. Scale-up of this process has not been successfully achieved due to challenges that still exist in the process. This study is aimed at understanding the effect operational conditions to elucidate their contribution to the products yield and purity.
Effect of seeding on product quality in batch antisolvent crystallization of Rare Earth Elements
Antisolvent crystallization is a novel technology for REE recovery from waste materials such as spent NiMH batteries and mine dumps. High supersaturation generated in antisolvent crystallization results in fine product crystals due to uncontrolled nucleation. The project aims to explore how seeding can be utilised in batch antisolvent crystallization to attain larger particle sizes with narrow PSD for easier handling.
Investigating the effect of mixing on crystal growth during antisolvent crystallization of REE from NiMH battery leach liquors
In this study, it was proposed to design an antisolvent crystallization process to recover REEs from NiMH batteries synthetic leach liquors using a confined impinging jet crystallizer. The study will primarily focus on the effect of mixing/hydrodynamics on the crystal size and crystal size distribution with neodymium sulphate as a model system.
Crystallization and Precipitation Research Unit
Department of Chemical Engineering
University of Cape Town
New Chemical Engineering Building
Private Bag X3
Rondebosch 7701 E-mail: firstname.lastname@example.org Tel: 021 650 4583