7/24/2019 AmiraProject_p879

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The mineral industry research association

P879 Microwave Assisted Comminution and Liberation of Minerals

August 2003

Executive Summary

The mining industry needs to enhance liberation andseparation of minerals and reduce energy consumption inorder to increase efficiency and treat the lower grade orebodies. The industry aims to achieve higher throughput,whilst increasing the limit of grind, increasing recovery ofmetal. Research work by the proposers of this project hasshown that microwave treatment of ores prior tocomminution can induce fracture around individual mineralgrains leading to enhanced processing and potentiallyimproved process economics.

Previous work on microwaves in the minerals industry

utilised low power systems that necessitated longresidence times. In addition, small sample masses wereused which led to poor energy balances (microwave energyinput > 40 kWh/t). The proposers of this project haveadopted a different strategy, combining sound fundamentalunderstanding and interdisciplinary skills, to achievesignificant process benefits at a microwave energyconsumption of less than 0.5kWh/t. In addition, furtherunderstanding will be developed by carrying out, for thefirst time, a full evaluation of pulsed technology. Ifsuccessful, this will lead to even lower microwave energyconsumptions, significantly higher throughputs andpotentially the liberation of minerals at their natural grainsize.

Two options are offered for the first year of this four year

project, whose ultimate aim will be to a design and build alarge scale demonstration plant

A basic opti on for sponsors who wish to performpreliminary evaluation of the technology for their ores andwho wish to assess the effects of treatment themselves.

An extensive option for sponsors who wish for moreextensive and optimised evaluation, which will includetesting at a range of higher power densities, detaileddielectric property measurements development of designconcepts for continuous operation and full techno-economic evaluation for the design concepts.

The potential benefits to sponsors are:The gated nature of the programme means that sponsors

will be able to assess the technology as appropriate to theirneeds during the first year of the programme. The first yearwill provide sponsors with a preliminary evaluationopportunity prior to committing to the major 2 year phasethat will follow. The first phase will also identify the specificprocess benefits that can be achieved for each of thesponsors, which could be in terms of selective breakage,enhanced liberation and reduced comminution energy etc.In years 2-3, sponsors will be able to evaluate their ownmaterials at pilot scale and receive the basic enablingknowledge to decide on likely process benefits withother materials without significant further testwork. It willthen be possible to readily quantify benefits at scaleandallow scope estimate economic analyses to be carried out.

The project will allow sponsors to evaluate their ores in acustom designed pulsed microwave test system notavailable elsewhere. The output from year 4 will allowsponsors to test their ores on site with an engineered,robust 20-100 tph microwave treatment system. In addition,the project will provide the scientific and engineering basisto allow individual sponsors to develop microwavetechnology for their own specific applications and ore typesoutside the remit of this project e.g. hydrometallurgy andpyrometallurgy.

Project Leaders Dr Sam Kingman (Nottingham)andProf Steven Bradshaw (Stellenbosch)

Research

Institutions

Universities of Nottingham (UK) and

Stellenbosch (RSA). e2v Technologies

Project Duration Four (4) Years, gates after years 1and 3

Project Status Under circulation

Project Type Mineral Processing

Sponsorship Year 1 Basic option A$66 700,Extended option A$123 750

ConfidentialityA standard AMIRA project confidentiality agreement will beexecuted. Sponsors retain a royalty free, perpetual, non-exclusive license to use research project technology in their

own operations.

Further Information

Richard BeckAMIRA International Africa OfficeResearch Co-ordinatorBuilding 88, Studio Office Park, 5 ConcourseCrescent, LonehillJohannesburg, South AfricaPhone: + 27 11 745 1522Cell pone 08 654 6818Email: richard.beck@amira.com.au

Chalcopyrite grain surrounded by calcite showing phaseboundary fracture as a result of pulsed microwave