Development of a geometallurgical testing framework for ore grinding and liberation properties
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Efficient measurement methods for comminution properties are an important prerequisite for testing the variability of an ore deposit within the geometallurgical context. This involves the investigation of effects of mineralogy and mineral texture on the breakage of mineral particles. Breakage properties of mineral particles are crucial for the liberations of minerals and the energy required for that.
For process optimization and control purposes, comminution indices are often used to map the variation of processing properties of an entire ore body (e.g. Bond work index). Within the geometallurgical approach this information is then taken up when modelling the process with varying feed properties.
The main focus of this thesis work has been to develop a comprehensive geometallurgical testing framework, the Geometallurgical Comminution Test (GCT), which allows the time and cost efficient measurement of grinding indices and their linkage to mineralogical parameters (e.g. modal mineralogy or mineral texture, mineral liberation).
In this context a small-scale grindability test has been developed that allows estimating the Bond work index from single pass grinding tests using small amounts of sample material. Verification of the evaluation method and validation was done with different mineral systems.
For selected samples the mineral liberation distribution was investigated using automated mineralogy. By transferring the energy-size reduction relation to energy – liberation relation new term liberability has been established.
As part of the experimental investigations, mineralogical parameters and mineral texture information were used for predicting breakage and liberation properties. Patterns for describing the breakage phenomena were established for a set of iron oxide ore samples. The determined breakage patterns indicated that the specific rate of mineral breakage slows down when reaching the grain size of mineral particles, thus allowing maximizing mineral liberation significantly without wasting mechanical energy.
Place, publisher, year, edition, pages
Luleå University of Technology: Luleå University of Technology, 2016.
Grindability test, mineral texture, breakage properties, mineral liberation, process modeling, geometallurgy
Metallurgy and Metallic Materials
Research subject Mineral Processing
IdentifiersURN: urn:nbn:se:ltu:diva-59904ISBN: 978-91-7583-737-6 (print)ISBN: 978-91-7583-738-3 (electronic)OAI: oai:DiVA.org:ltu-59904DiVA: diva2:1039474
2016-12-15, D770, LTU, Luleå, 10:00 (English)
Benzer, Hakan, Profesor
Rosenkranz, Jan, Chair Profesor