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

• 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

Ph.D. Natalia Petrovskaya, February 3, 2016

References

1. http://mine-engineer.com/mining/minproc/elstat1.htm

2. http://www.mineraltechnologies.com/process-solutions/equipment-design-selection/electrostatic-separation

3. http://www.minsocam.org/ammin/AM21/AM21_115.pdf

4. http://digital.library.unt.edu/ark:/67531/metadc12827/m2/1/high_res_d/Bulletin0685.pdf

5. http://www.essenscia.be/Upload/Docs/Plastic%20separation%20by%20triboelectricity.pdf

6. http://waset.org/publications/6082/triboelectric-separation-of-binary-plastic-mixture

7. http://www.nanopowder-technology.com/en/?page=668

8. http://iopscience.iop.org/article/10.1088/1742-6596/418/1/012073/meta

9. http://www.galleries.com/minerals/property/electric.htm

10. http://www.hindawi.com/archive/1993/038783/abs/

11. http://www.electrostatics.org/images/d3.pdf

12. http://crack.seismo.unr.edu/ftp/pub/louie/class/492/data/2011/GPH492_ALL_FILES_2011/AppliedGeophysics_Telford/AppliedGPH_ElectricalPropertiesOfRocksAndMinerals.pdf

13. http://coalguide.ru/elektricheskoe-obogashchenie/267-obshchie-svedeniya-i-klassifikatsiya-protsessov-elektricheskogo-obogashcheniya/

14. http://vikidalka.ru/1-133787.html

15. https://books.google.cl/

16. http://incompliancemag.com/article/useful-static-electricity/

17. http://www.google.com/patents/US20030192813

18. https://pure.ltu.se/portal/files/1705494/Novel_Fluidised-bed_Tribo-electrostatic_Separator.pdf

19. http://www.nanopowder-technology.com/en/?page=668