Resume

• 2003

  Doctor of Philosophy (PhD)

  The effect of thermal treatment on the physicochemical properties of minerals

  Chemical Engineering

  The University of Birmingham

• 2002

  Master of Science (MSc)

  Instrumentation and Analytical Science

  University of Manchester - Institute of Science and Technology

• 1998

  Chemical Engineering with German

  University of Manchester - Institute of Science and Technology

• Scanning Electron Microscopy

  Science

  Cell

  Microsoft Office

  Flotation

  Nanotechnology

  Characterization

  Materials Science

  Metallurgy

  Powder X-ray Diffraction

  Geology

  Mineral Processing

  Process Engineering

  Chemical Engineering

  Simulations

  Nanomaterials

  Physics

  Minerals

  Experimentation

  Chemistry

  Developing critical coalescence concentration curves for industrial process waters using dilution

  James A. Finch

  Developing critical coalescence concentration curves for industrial process waters using dilution

  Richard Sheridan

  Rare earth (RE) mineral deposits are typically processed using several different unit operations including flotation

  gravity

  magnetic and electrostatic separation techniques. Two of the most important beneficiation techniques for RE minerals are gravity and magnetic separation. Many RE minerals are found alongside low specific gravity gangue minerals thereby permitting the use of gravity separations to concentrate the heavy value RE minerals. Magnetic separation is used primarily to remove ferromagnetic gangue minerals as well as to separate individual paramagnetic rare earth minerals. \nThis work investigated the use of a wet high intensity magnetic separation (WHIMS) in conjunction with gravity pre-concentration steps (Knelson and Falcon centrifugal concentrators) to beneficiate a rare earth ore. The results of these separation steps are related to the magnetic properties of RE minerals

  based on literature and measurements conducted using a vibrating sample magnetometer (VSM). \n

  Processing a rare earth mineral deposit using gravity and magnetic separation

  Surface Characterisation of Fergusonite

  R. Gauvin

  P. Chu

  Mitra Mirnezami

  A. Jordens

  There is currently very little information on the physico–chemical properties of rare earth element bearing minerals

  or on their processing. With the increasing demand for rare earths

  this is something that needs to be addressed. This paper introduces some surface chemistry analysis of fergusonite (YNbO4)

  and the bubble particle attachment. Zeta potential measurements indicate adsorption of sodium oleate and

  to a lesser degree

  potassium amyl xanthate onto the surface

  and an increase in attachment to an air bubble is observed at pH 4?5 and 6?5. At a pH of 10?5

  no attachment is observed

  whether in the presence of the reagents or not. This analysis

  although initial

  will be used to initiate flotation tests

  in order to facilitate the selective recovery of fergusonite. Two extensively characterised minerals

  one hydrophilic (quartz) and one hydrophobic (galena) were also investigated as a comparison.

  Surface Characterisation of Fergusonite

  Olga Kuzmina

  Bastnäsite is the chief valuable mineral in two of the world’s largest rare earth (RE) mineral deposits and is also found in a number of new RE deposits currently under development. This work used electrophoretic and electroacoustic zeta potential measurements to identify the interaction between bastnäsite and several different collectors. The results of these measurements were then compared with microflotation of bastnäsite and quartz

  a common RE gangue mineral. Zeta potential measurements of bastnäsite determined the isoelectric point of bastnäsite to occur at approximately pH 6.3 (via electrophoretic measurement) and pH 8.1 (via electroacoustic measurement). Sodium oleate and Flotinor SM15 (a commercial phosphoric acid ester) are both shown to chemically adsorb onto the bastnäsite surface. Zeta potential measurements of bastnäsite with benzohydroxamic acid indicate significant adsorption

  especially from pH 5 to pH 10. The microflotation results show that all three collectors were able to successfully recover bastnäsite. SM15 is the least selective collector as it floats both quartz and bastnäsite whereas benzohydroxamic acid is able to selectively float bastnäsite at pH 9. The recovery of bastnäsite using benzohydroxamic acid is also shown to be highly dependent on frother selection. The optimum pH of flotation for all three collectors occurs at pH 9.

  Surface chemistry considerations in the flotation of bastnasite

  Determining frother-like properties of process water in bitumen flotation

  James A.Finch

  Determining frother-like properties of process water in bitumen flotation

  A review of the beneficiation of rare earth element bearing minerals

  Y.P. Cheng

  Rare earth elements (REEs) comprise the fifteen elements of the lanthanide series as well as yttrium

  and may be found in over 250 different minerals. These elements are required for many different applications such as high-strength permanent magnets

  catalysts for petroleum refining

  metal and glass additives and phosphors used in electronic displays. The only REE bearing minerals that have been extracted on a commercial scale are bastnäsite

  monazite

  and xenotime. These minerals may be beneficiated using gravity

  magnetic

  electrostatic and flotation separation techniques. Increased demand for the different products manufactured from REE has resulted in a constriction of supply from China

  which currently produces 97% of the world’s rare earths

  via export quotas. Many new rare earth deposits are currently being developed to help meet the demand void created by the Chinese export quotas

  however most of these developing deposits include rare earth minerals for which there is limited processing knowledge. This paper examines the separation techniques that are currently employed for rare earth mineral beneficiation and identifies areas in need of further research.

  A review of the beneficiation of rare earth element bearing minerals

  Conor Maloney

  The need for fine grinding to liberate valuable minerals from low-grade ores has become a major concern due to the high energy requirements and\nlow energy efficiencies of comminution processes. One method being studied to improve efficiencies is microwave pre-treatment. Microwaves can\nselectively heat certain minerals (absorbers) within an ore

  causing internal stresses and forming fractures along grain boundaries. Microwave pretreatment\nof an ore containing microwave-absorbing minerals and microwave-transparent gangue can significantly reduce grinding energy.\nHowever

  these improvements must not be detrimental to downstream processing. This work investigated the effects of microwave radiation on the\ngrindability and flotability of a copper/nickel sulphide ore. A reduction in the Bond Work Index of 22%was observed after microwave pre-treatment\nin a 3.0kW multimodal microwave (2.45 GHz) for 60 s. Although a significant reduction in the required grinding energy was observed

  the amount\nof energy required to treat the sample is significantly higher than the corresponding Bond Work Index reduction

  indicating that the process remains\nsome distance from being economically viable. Microwave pre-treatment also showed beneficial effects on the flotation of the ore. Copper recovery\nremained constant while nickel recovery increased by 33.6% after 120 s of microwave exposure at 0.8 kW

  and by 34.4% after a 30 s exposure at\n3.0 kW. Higher microwave exposure also showed an increase in concentrate grade and flotation kinetics of both copper and nickel.

  Effect of microwave radiation on the processing of a Cu-Ni sulphide ore

  Inverse gas chromatography has great potential in allowing an enhanced understanding of mineral surfaces

  and the interactions between particles and air and water in mineral processing separations

  such as flotation.\n\nTwo minerals of different degrees of natural hydrophobicity were investigated

  namely galena and quartz. The surface energy was determined as a function of surface area

  with the quartz sample displaying a higher work of adhesion

  implying a higher degree of hydrophilicity. This was then compared to microflotation experiments. The higher work of adhesion to water for the quartz than galena (114.54 mJ m− 2 compared to 101.71 mJ m− 2 @ 5% coverage; 86.78 mJ m− 2 compared to 71.69 mJ m− 2 @ 38% coverage) was related to a lower recovery of quartz (6.94%) than galena (27.63%) through collectorless flotation.

  Introducing inverse gas chromatography as a method of determining the surface heterogeneity of minerals for flotation

  Olga Kuzmina

  This paper investigated the physicochemical properties of allanite

  a RE-silicate

  by measuring zeta potential in the absence and presence of three different flotation collectors (benzohydroxamic acid

  sodium oleate and dodecylamine). This data was then verified by microflotation experiments and with bubble-particle attachment pictures. The investigated properties of allanite were compared to those of quartz

  a common gangue mineral in many RE deposits. The results of this work indicated that only dodecylamine was able to achieve a selective separation of allanite and quartz. This was accomplished by lowering the dodecylamine dosage so that only quartz was recovered by microflotation.

  Physicochemical aspects of allanite flotation

  Neil Rowson

  James Finch

  Raymond Langlois

  Thomas Leadbeater

  For the past 120 years

  hydrocyclones have been used a wide variety of industrial applications

  with their main use in mineral processing being as a classifier. Hydrocyclone characterization relies heavily on empirical and phenomenological models. There is a need to develop a method by which the flow patterns can be quantified under industrial conditions. Positron emission particle tracking (PEPT)

  developed by the University of Birmingham in the late 1980s

  has proven to be a powerful in situ visualization tool for engineering applications. This paper presents data on the motion of quartz particles in a two-inch hydrocyclone using the PEPT technique. Quartz tracer particles were labeled using the direct activation technique. The particle size range was between −2000 and +150 μm which illustrates the flow pattern of particles reporting to the underflow.

  Particle flow visualization in quartz slurry inside a hydrocyclone using the positron emission particle tracking technique

  Waters

  Imperial College London

  McGill University

  Research work involved the separation of fine mineral particles through flotation using colloidal gas aphrons\n\nParticle tracking in a froth flotation cell using the positron emission particle tracking (PEPT) technique

  Post Doctoral Research Associate

  London

  United Kingdom

  Imperial College London

  Associate Professor

  Montreal

  Canada Area

  McGill University

  My research involves mineral processing

  specifically separation techniques. These include froth flotation

  magnetic separation and gravity concentration.\n\nCurrent research work includes:\nProcessing rare earth bearing minerals\nDry processing of minerals\nRemoval of heavy metals from water\nModelling spiral concentrators

  Assistant Professor

  Montreal

  Canada Area

  McGill University