The demand for minerals and metals is increasing. However, it is well established that the impact of mining and subsequent processing operations must be reduced to meet future sustainability requirements. One way in which mining operations may reduce their impact is through the use of emerging science and technology. One such area which has shown particular promise over a period of several years is the use of microwave heating technologies to improve the efficiency of various mineral processing unit operations including: leaching, refractory gold ore treatment, grindability and liberation and coal grinding. Each of the above areas is reviewed and the main reasons that have either ensured or hindered development to a pilot or industrial scale are discussed. Opportunities for the future development of microwave technologies for the minerals industry are discussed and the review concludes by identifying a series of research challenges that must be met before scale up to an industrial level can be considered.
Get full access to this article
View all access options for this article.
References
1.
Anon., (1999) ‘Technology foresight — natural resources and environment’,Office of Science and Technology, London, UK.
2.
AppletonT. J.ColderR. I.KingmanS. W.LowndesI. S.ReadA. G., (2005) ‘Microwave technology for energy efficient processing of waste’, Appl Energ., 81, 85–113.
3.
Al-HarahshehM.KingmanS. W., (2004) ‘Microwave assisted leaching — a review’, Hydrometallurgy, 73, 189–203.
4.
Yu.BykovRybakovV.,Semenov, V. E.K. I. (2001) ‘Topical review. High-temperature microwave processing of materials’,J. Phys. D: Appt Phys., 34, 55-75.
5.
BradshawS. M.KingmanS. W., (2003) ‘Modelling microwave heating of ores’, Ampere, International Microwave Heating Symposium, Loughborough, UK.
6.
ChenT. T.DutrizacJ. E.HagueK. E.WyslouzilW.KashyapS., (1984) ‘The relative transparency of minerals to microwave radiation’, Can. Metall. Q., 23, 349–351.
7.
ClarkD. E.FolzD. C.WestJ. K., (2000) ‘Processing materials with microwave energy’, Mater. Set Eng. A, 287, 153–158.
8.
ConroyA. P., (1994) ‘Grinding behaviour of hard coals’, Combust. News, 5, 1–4.
9.
ConroyA. P.SligarN. J., (1991) ‘The effect of coal moisture content and internal recirculation on vertical spindle mill through-put and wear’, NERDDC project, Australian Combustion Technology Centre, 87pp.
10.
GalemaS. A., (1997) ‘Microwave chemistry’, Chem. Soc. Rev., 26, 233–238.
11.
HarrisonP. C.RowsonN., (1997) ‘The effect of heat treatment on coal grindability’, IChEME Research Event, Nottingham, UK.
12.
HagueK. E., (1987) ‘Gold leaching from refractory ores — literature survey’, Miner. Process. Extract. Metall. Rev., 2, 235–253.
13.
HagueK. E., (1987) ‘Microwave irradiation treatment of a refractory gold concentrate’. In: Salter,R. S.Wyslouzil,D. M.McDonald,G. W.Proc. Int. Symp. on ‘Gold metallurgy’,327-339, Winnipeg, Canada.
14.
HagueK. E., (1999) ‘Microwave energy for mineral treatment processes — a brief review’, Int. J. Miner. Process., 57, 1–24.
15.
HuangJ. H., (2000) ‘The application of microwave energy to improve grindability and extraction of gold ores’, thesis, University of Birmingham, Birmingham, UK.
16.
HuangJ. H.RowsonN. A., (2002) ‘Hydrometallurgical decomposition of pyrite and marcasite in a microwave field’, Hydrometallurgy, 64, 169–179.
KingmanS. W.RowsonN. A., (1998) ‘Microwave treatment of minerals – a review’, Miner. Eng., 11, 1081–1087.
20.
KingmanS. W., (1999) 'Microwave treatment of ores and mineral', PhD thesis,University of Birmingham,Birmingham, UK.
21.
KingmanS. W.CorfieldG. M.RowsonN. A., (1999)
22.
KingmanS. W.RowsonN. A., (2000) ‘The effect of microwave radiation on the magnetic properties of minerals’, J. Microwave Power Electromagn. Energ., 35, 141–150.
23.
KingmanS. W.VorsterW.RowsonN. A., (2000) ‘The effect of microwave radiation on the processing of Palabora copper ore’, J. S. Afr. Inst. Min. Metall., 197–204.
24.
KingmanS. W.VorsterW.RowsonN. A., (2000) ‘The influence of mineralogy on microwave assisted grinding’, Miner. Eng., 13, 313–327.
25.
KingmanS. W.BradshawS.JacksonK.CumbaneA.RowsonN.GreenwoodR., (2004) ‘Development of micro-wave assisted comminution’, Int. J. Miner. Process., 74, 71–83.
26.
KingmanS. W.JacksonK.BradshawS.RowsonN. A.GreenwoodR., (2004) ‘An investigation into the influence of microwave treatment on mineral ore comminution’, Powder Technol, 146, 176–184.
27.
LesterE.KingmanS., (2004) ‘Effect of microwave heating on the physical and petrographic characteristics of a UK coal’, Energ. Fuel., 18, 140–147.
28.
LesterE.KingmanS., (2004) ‘The effect of microwave preheating on five different coals’, Fuel, 83, 1941–1947.
29.
LovasM.MurovaI.MockovciakovaA.RowsonN.
30.
MarlandS.HanB.MerchantA.RowsonN., (2000) 'The effect of microwave radiation on coal grindability', Fuel,79, 1283-1288.
31.
MarlandS.MerchantA.RowsonN., (2001) ‘Dielectric properties of coal’, Fuel, 80, 1839–1849.
32.
MeredithR. J., (1998) ‘Engineers’handbook of industrial microwave heating', Institution of Electrical Engineers, London.
33.
MetaxasA. C.MeredithR. J., (1983) ‘Industrial microwave heating’, Peter Peringrinus, London.
34.
MingosD. M. P.BaghurstD. R., (1991) ‘Application of microwave dielectric heating effects to synthetic problems in chemistry’, Chem. Soc. Rev., 20, 1–47.
35.
Napier-MunnT. J. (1996) ‘Mineral comminution circuits. Their operation and optimisation’. JKMRC Monograph Series in Mining and Mineral Processing2.
36.
PetrukW., (2000) ‘Applied mineralogy in the mining industry’, 1st edn., Elsevier Science, Amsterdam.
37.
PicklesC.XiaD. K., (1997) ‘Applications of microwave energy in extractive metallurgy, a review’, CIM Bull., 90, 96–107.
38.
SahyounC.KingmanS. W.RowsonN. A., (2003) ‘The effect of heat treatment on chalcopyrite’, Phys. Sep. Sci. Eng., 12, 23–30.
39.
ThostensonE. T.ChouT.-W., (1999) ‘Microwave processing: fundamental and applications’, Composites: Part A, 30, 1055–1071.
40.
TranquillaJ. M., (1997) ‘Mineral extraction and the use of microwaves’. Presented at CIM conference, Vancouver, BC, Canada.
41.
US Department of Energy (2000) ‘Mining industry of the future; mineral processing roadmap’.http://www.eere.energy.gov/industry/ mining/pdfs/mptroadmap.pdf(date last accessed, February 2005). Uslu, T. and Atalay, U., (2003) ‘Microwave heating of coal for enhanced magnetic removal of pyrite’, Fuel Process. Technol, 85, 21-29.
42.
UsluT.AtalayU.ArolA. I., (2003) ‘Effect of microwave heating on magnetic separation of pyrite’, Colloids Surf A: Physicochem. Eng. Aspects, 225, 161–167.
43.
UsluT.AtalayU.ArolA. I., (2003) ‘Effect of microwave heating on magnetic separation of pyrite’, Colloids Surf. A: Physicochem. Eng. Aspects, 225, 161–167.
44.
VorsterW.RowsonN. A.KingmanS. W., (2001) ‘The effect of microwave radiation upon the processing of Neves Corvo copper ore’, Int. J. Miner. Process., 63, 29–44.
45.
WalkiwiczJ. W.KazonichG.McGillS. L., (1988) ‘Microwave heating characteristics of selected minerals and compounds’, Miner. Metall Process., 5, 39–42.
46.
WhittlesD. N.KingmanS. W.ReddishD. J., (2003) ‘Application of numerical modelling for prediction of the influence of power density on microwave-assisted breakage’, Int. J. Miner. Process., 68, 71–91.
47.
WhittlesD.KingmanS. W.LowndesI. S., (2005) ‘An investigation into the parameters affecting mass flow rate of ore material through a microwave continuous feed system’, Adv. Powder Technol, to be published.
48.
ZavitsanosP. D., (1979) ‘Coal desulphurisation using microwave energy’, US Patent No. DOE.PC30142–71.
49.
ZnamenackovaI.LovasM.MockovciakovaA.JababskyS.BriancinJ., (2005) ‘Modification of magnetic properties of siderite ore by microwave heating’, Sep. Purif. Technol., 43, 169–174.
