CLASSIFICATION OF MINERALS ON THE ELECTRICAL PROPERTIES

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
• Piezoelectric effect
• Triboelectric effect
• Triboluminescence

TYPES OF ELECTROSTATIC SEPARATORS

• Electrostatic separators
• Corona-electrostatic separators
• Tribo-electrostatic separators
• Tribo adhesive separators (TAS)
• Dielectric separators
• Electrostatic classifiers

HOW TO CHOOSE A METHOD FOR THE SEPARATION OF MINERALS

Ph.D. Natalia Petrovskaya, February 3, 2016