Practical trainings, student assistants and theses

Competitive bubble-particle attachment from a particle mixture in a model stirred cell (Id 405)

Master theses / Diploma theses / Compulsory internship

Foto: Particles on bubble in cell ©Copyright: Dr. Milad Eftekhari Flotation is a widely used technique worldwide to extract valuable minerals from less valuable ones. To make the process more efficient, several methods have been developed to investigate how various factors affect particle floatability (recovery). Traditionally, this is done by measuring the hydrophobicity of the particles. However, floatability is a much broader concept that encompasses not only hydrophobicity but also other factors such as hydrodynamic conditions. In our research, we introduce a novel approach to quantify particle floatability from a mixture through dynamic bubble surface coverage experiments, considering hydrodynamic effects. Our focus is to understand how the different particles attach to a single bubble from a system containing two (or three) different particle types (chalcopyrite and/or pyrite + quartz). In particular, how one type of particle affects the recovery of another type.

Our objective is:

  • To study the effect of pH and collector concentration on particle floatability.
  • To establish a correlation between floatability and flotation recovery.
Experimental methods/techniques:
  • Image acquisition and analysis
  • Particle size analysis techniques such as laser diffraction and dynamic light scattering

Department: Transport processes at interfaces

Contact: Dr. Eftekhari, Milad, Öktem, Gülce

Requirements

  • duration min. 6 month, workplace: HZDR

Online application

Please apply online: english / german

Druckversion


Dynamics of bubble-particle attachment in a model stirred cell (Id 404)

Master theses / Diploma theses / Compulsory internship

Foto: Dynamics of bubble-particle attachment in a model stirred cell ©Copyright: Dr. Milad EftekhariA process called flotation is widely used throughout the world to separate valuable minerals from non-valuable ones. Successful flotation relies on several sub-processes, such as promoting the attachment of certain sizes of particles to bubbles while preventing the attachment of others. Therefore, it is important to advance our knowledge about the particle attachment process, particularly, when different particle sizes are considered. Here we use our in-house setup to study:

  • The effect of ultrafine particles on the attachment rate of fine particles.
  • The effect of various parameters e.g., particles hydrophobicity on the packing density of the particles.
Experimental methods/techniques:
  • Image analysis
  • Particle size analysis techniques such as laser diffraction and dynamic light scattering

These experimental methods and the topic of particles at interfaces can prepare you for a variety of jobs after graduation, as these concepts are widely applicable in various fields such as mineral processing, recycling, pharmaceuticals, cosmetics, painting, and so on.

Department: Transport processes at interfaces

Contact: Dr. Eftekhari, Milad, Dr. Schwarzenberger, Karin

Requirements

  • Study in process engineering, chemical engineering (or comparative field of study)
  • Motivation, interest in this field of research, experimental experience
  • Optimally: basic knowledge of particle measurement techniques

Conditions

duration min. 6 month, start: from now, workplace: HZDR

Online application

Please apply online: english / german

Druckversion