Electrical separation
Classification of minerals on the electrical properties:
Conductors are minerals with high conductivity.
Semiconductors are minerals that have an average (low) conductivity.
Non-conductors (dielectrics) are minerals that don't conduct electricity.
Conductores: Anthracite, argentite, arsenopyrite, bornite, braunite, cassiterite (ferriferous), chalcocite, chalcopyrite, cobaltite, columbite, copper, covellite, chromite, enargite, galena, gold, graphite, hematite, ilmenite, magnetite, manganite, marcasite, molibdenite, pyrite, pyrolusite, pyrrhotite, rutile, silver, smaltite, titanomagnetite, wolframite.
Semiconductors: bauxite, cassiterite, cuprite, limonite, magnesite, siderite, sphalerite, vermiculite
Non-conductors: Actinolite, albite, almandite, andesite, anglesite, anhydrite, apatite, azurite, barite, beryl, biotite, calcite, celestite, cerussite, chrome, chrisocolla, chlorite, corundum, crocidolite, crocoite, chromite, cryolite, diamond, diaspore, diopside, dolomite, enstatite, epidote, feldspar, fluorite, franklinite, gibbsite, quartz, halite, monazite,muscovite, phlogopite, scheelite, spinel, spodumene, staurolite, stibnite, stibnite, sylvite, talc, titanite, topaz, tourmaline, wollastonite, wulfenite, xenotime, zircon.
It is easy to separate conductors out of non-conductors. It is more complicated to separate semiconductors out of conductors or non-conductors.
The electrical separation is very useful for separate next minerals:
Gold and platinum
Diamond and rock minerals
Ilmenite and apatite, garnet, tourmaline, zircon
Cassiterite and monazite, zircon, scheelite, spodumene
Rutil and monazite, zircon
Monazite and cassiterite, columbite, rutil
The electrical separation is used for:
Separation of placer deposits of rare earth minerals
Separation of tin and tungsten ores
Separation of ferrous metals ores
Separation of non-metallic minerals: quartz, feldspar, coal, mica
Secondary metals: non-ferrous and ferrous metals, solid waste
Dedusting and dust collection
Separation of materials by size: building materials, ores
TYPES OF ELECTRICAL SEPARATION
There are 6 types of electrical separation of minerals:
Electrical separation
Electrostatic separation
Dielectric separation
Tribo-electrostatic separation
Tribo adhesive separation
Separation in the corona–discharge field
Rare types of electrical separation of minerals:
Electrical classification by size and shape
Pyroelectric separation
Tribo-aero-electrostatic separation
Pneumoelectric separation
Fluidising-electrostatic separation
Crown-magnetic separation
Opto-electrical separation
Electrical separation is used frequently with magnetic separation and gravity separation. Flotation can be used for eliminate silycates out of the iron concentrate.
Next effects exist in nature:
Thermoelectric effect
Pyroelectric effect
Photoconductivity
Photo-electromotive-force effect (EMF)
Photoluminescence
Triboelectric effect
Triboluminescence
TYPES OF ELECTROSTATIC SEPARATORS
Electrostatic separators
Corona-electrostatic separators
Tribo-electrostatic separators
Tribo adhesive separators (TAS)
Dielectric separators
Electrostatic classifiers
Ph.D. Natalia Petrovskaya, February 3, 2016
References
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