Scholarly record
BENEFICIATION OF NICKELIFERROUS LATERITE BY PHYSICAL AND CHEMICAL PROCESSES
Abstract
Nickeliferrous laterite is a source of ferronickel alloy extracted by a pyro-metallurgical process. Laterite deposits found in Greece are mainly secondary depositions and their nickel content is about 1\%. Beneficiation of the run of mine ore is limited to the +1 mm fraction by magnetic or gravitational processes and its effect is rather unsatisfactory due to the insufficient liberation of the nickel bearing minerals. The mineralogical structure of the ore consists mainly of hematite nodules (pissoids) and quartz grains cemented together with a softer material made also of hematite and quartz as well as nickel bearing magnesium silicate minerals of very fine grain size. The hematite nodules themselves are not pure hematite but they contain inclusions of quartz, nickel bearing magnesium silicate minerals and some chromite that are also found in the cement material. This mineralogical structure makes the beneficiation of laterites a low efficiency process that results to a low grade feed for the pyro-metallurgical plant that produces ferronickel alloy. The production cost depends mainly on the feed grade and there is always an interest for a higher grade feed material. Initially the present work examines the selective grinding between the hematite nodules and the softer cement material the result of which is the enrichment of nickel in the slimes. Consequently it examines the liberation of the material at fine sizes below the size of the nodules by mineralogical analysis. Physical methods like magnetic separation, centrifugal separation and froth flotation are used for the beneficiation of the deslimed fine material with limited results. Finally acid leaching is used for the recovery of nickel from the deslimed fine material with much better results than the ones obtained by physical separation processes. There is an obvious selectivity in leaching between nickel bearing magnesium silicate minerals like chlorite or serpentine and the iron bearing minerals like hematite. Selective grinding can produce a high-grade solid concentrate of slimes that after pelletizing can be used as feed material to the existing pyro-metallurgical plant for the production of ferronickel alloy. Hydro-metallurgical treatment of the low-grade sand material can be considered as a new development in the existing system. The combination of physical and chemical processes gives a better overall recovery than chemical treatment of the whole material and ensures a higher grade feed material to the existing high cost pyro-metallurgical plant.
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References9
Agatzini S. (1998) “A new approach to the metallurgical treatment of nickeliferrous laterites” E.U. project No 8188 (years 1994-1998)
Agatzini S., Dimaki D. (1998) “Heap leac hing of poor nickel laterites by surphuric acid” Int. Symp. Of Hydrometallurgy, IMM and SCI Cambridge, England, p. 193- 208
Boskos E., Orphanoudaki A., Perraki Th., (2000) “The Ni distribution in the mineral phases of Greek Fe-Ni laterite deposits”, Proceedings of the 3 rd Mineral Wealth Conference , Technical Chamber of Greece, Athens, vol. A, p.107-115
Drakakis D. (2000), “ Beneficiation of residual laterite from Kastoria area”, dissertation, Technical Univ ersity of Crete, Mineral Resources Engineering dept, Chania
Maratos G., (1972) “Geology of Greece”, Ge.Mel.Er. Athens
Martini S., (2004) “Study for the liberation and beneficiation of nickeliferrous laterite” dissertation, Technical University of Crete, Mineral Resources Engineering Department, Chania, Greece.
Stamboliadis E., Tzachrista V. (1996) “ Study for the beneficiation of the ferro- nickel lateritic ore from Kopais deposit, Technika Chronika, Scientific Journal of the Technical Chamber of Greece, section C, vol 16,1-2 p.17-27
Stamboliadis E., (2003) “Impact crushing approach to the relationship of energy and particle size in comminution”, European J.of Min. Proc. & Env. Prot. vol 3,2 p.160-166
Stamboliadis E., Alevizos G., Zafiratos J. (2003) “Leaching residue of laterites as a source of iron ore concentrate” Minerals Engineering, vol 17,2 p.245-252
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