Vermiculite

1
Vermiculite
2
Vermiculite

• Definition
• Minerals with micaceous morphology commonly
  formed by the alteration of biotite and
  Iron-bearing phlogopite.
• Supergene alteration product formed by the
  combined effects of weathering and circulating
  groundwater.
• (Mg,Ca,K,Fe2)3 (Si,AL,Fe3)4O10(OH)2O4H2O,
  Hydrated Magnesium Iron Aluminum Silicate
  Hydroxide

http//mineral.galleries.com/minerals/silicate/ver
micul/vermicul.htm
3
Vermiculite - Class

• Class Silicates
  
• (SiO4)
• Subclass Phylosilicates
  (The Sheet Structures)
• Groups The Clays and the Monmorillonite /
  Smectite Group
• (It is sometimes put in the Mica group but recent
  analysis has excluded it from that group)

http//mineral.galleries.com/minerals/
4
Vermiculite- Physical Characteristics

• Color Brown to golden brown, can also be white,
  colorless, or yellow
• Luster Pearly to greasy
• Transparency Translucent crystals
• Cleavage Perfect in one direction
• Fracture Uneven to lamellar
• Hardness About 1.5, which can sometimes leave
  marks on paper
• Specific Gravity 2.3-2.5
• Streak white
• Crystal System monoclinic, 2/m

(Hindman, 2006) http//www.hoben.co.uk/vermiculit
e/specs.htm
5
Vermiculite- Physical Characteristics

• Crystal Habit Pseudohexagonal tabular crystals
  (books), also compact or lamellar masses or
  microscopic crystals
• Other Characteristics When heated, crystals
  expand to many times their original volume.
• Sintering temperature 1260 Degrees C
• Melting Point 1330 Degrees C
• Specific Heat 1.8 kJ/kg.K.
• pH value 8.0-9.5
• Thermal Conductivity 0.062-0.0656W/mK

6
Vermiculite- Associated Minerals

• Corundum
• Apatite
• Serpentine
• Talc
• Stellerite
• Biotite
• Other clay minerals

http//mineral.galleries.com/minerals/
7
Vermiculite- Physical Characteristics

• There are water molecules within the internal
  structure of vermiculite, that when it is heated
  to high temperatures, the water transforms to
  steam, causing the particles to increase in
  volume.
• The thermal exfoliation increases the volume
  usually 10 to 20 times

(Hindman., 2006)
8
Vermiculite- Typical Chemical Analysis
(Hindman., 2006)
9
Vermiculite- Uses

• It is used in three primary forms
• Untreated Concentrate
• Thermally Exfoliated
• The ground products of chemical or thermal
  exfoliation

Vermiculite Unexpanded, Expanded and a Single
Particle
http//www.vermiculite.net/
10
Vermiculite- Uses (continued)

• CONSTRUCTION
• Acoustic finishes
• Air setting binder
• Board
• Fire protection (internal/external)
• Floor roof screeds (lightweight
• Insulating concrete)
• Gypsum plaster
• Loft insulation
• Sound deadening compounds

http//www.vermiculite.org/uses.htm (Kogel et al,
2006)
11
Vermiculite- Uses (continued)

• HORTICULTURAL
• Blocking mixes
• Hydroponics
• Micro-propagation
• Potting mixes
• Rooting cuttings
• Seed germination
• Seedling wedge mix
• Sowing composts
• Twin scaling bulbs

http//www.vermiculite.org/uses.htm (Kogel et al,
2006)
12
Vermiculite- Uses (continued)

• AGRICULTURAL
• Animal feed
• Anti-caking material
• Bulking agent
• Fertilizer
• Pesticide
• Seed encapsulant
• Soil conditioner

http//www.vermiculite.org/uses.htm (Kogel et al,
2006)
13
Vermiculite- Uses (continued)

• INDUSTRIAL
• Absorbent packing
• Brake pads brake shoes
• Castables
• Dispersions
• Drilling muds
• Filtration
• Fireproof safes
• Fixation of hazardous material
• Furnaces
• Insulation blocks shapes
• Insulation - high low temperature
• Molten metal insulation
• Molded products
• Nuclear waste disposal
• Paints
• Perfume absorbent
• Sealants

http//www.vermiculite.org/uses.htm (Kogel et al,
2006)
14
Exfoliated Vermiculite is great for thermal
insulation and can withstand temperatures over
1000 degrees Celsius. Vermiculite is easy and
clean to handle, odorless, sound absorbent,
non-abrasive, and will not decay.
Vermiculite is used as a packing material because
it is lightweight , it can form around objects,
it takes shock well, it can absorb leaks, and it
is not a fire hazard.
Vermiculite of medium grade will improve drainage
when added to heavy soils. Fine grade mixed with
peat is a great compost for growing seeds.
Vermiculite also helps fertilizers release more
nutrients which is more economical and efficient.
Vermiculite is also used in the friction
industry.
http//www.hoben.com/vermiculite/index.htm
15
Vermiculite- U.S. Occurrences
(Hindman, 2006)
16
Vermiculite- World Occurrences
(Hindman, 2006)
17
Vermiculite- Production
http//minerals.usgs.gov/minerals/pubs/commodity/v
ermiculite/vermimcs06.pdf
18
Vermiculite- U.S. Production and Trade
(Hindman, 2006)
19
Vermiculite- Processing
(Hindman, 2006)
20
Vermiculite- Production
Mining
Concentrate Crushing
Concentrate Drying
Ore Transport
Concentrate Classifying
Ore Storage
Concentrate Storage
Ore Screening
Product Grinding
Exfoliating
Ore Storage
Product Classifying
Ore Blending
Product Storage
Wet Processing
Most unexfoliated ore (640- 1,120 kg/m3) is
shipped in 100-ton hopper railcars in the U.S.
and Canada from the mills to the exfoliation
plants. Shipping in 10 to 20 ton trucks is
becoming more frequent. (Hindman, 2006)
http//www.epa.gov/ttn/chief/ap42/ch11/final/c11s2
8.pdf (Kogel et al., 2006)
21
Vermiculite- Exfoliation
Vertical furnace used in United States (Picured
below)
Rotary drum furnace used outside North America
(Hindman, 2006)
Principle of the Pipe-Exfoliation 1 unit of
dosage 2 heating pipe 3 deflection plates 4
radiation elements 5 cooling system 
http//www.vermiculite-furnaces.com/Exfoliator/exf
oliator.htmlAnlagenundOfenbau
22
Vermiculite- Crude/untreated
http//www.chinavermiculite.com/verm.htm
23
Vermiculite- Expanded/exfoliated
http//www.chinavermiculite.com/verm2.htm
24
TABLE 2 ACTIVE VERMICULITE EXFOLIATION PLANTS
IN THE UNITED STATES IN 2005 Company   Count
y   State Isolatek International,
Inc.  Sussex   New Jersey. J.P. Austin
Associates, Inc.  Beaver   Pennsylvania. Palmetto
Vermiculite Co., Inc. Spartanburg South
Carolina. P.V.P. Industries, Inc.   Trumbull Ohio.
Schundler Co., The   Middlesex New
Jersey. Southwest Vermiculite Co.,
Inc. Bernalillo New Mexico. Sun Gro Horticulture,
Inc.  Jefferson Arkansas. Do.   La
Salle   Illinois. Thermal Ceramics
Inc.   Macoupin Do. Thermo-O-Rock East,
Inc.  Washington Pennsylvania. Thermo-O-Rock
West, Inc.  Maricopa Arizona. Verlite
Co.   Hillsborough Florida. Vermiculite
Industrial Corp. Allegheny Pennsylvania. Whittemor
e Co., Inc.   Essex   Massachusetts. W.R. Grace
Co.   Maricopa Arizona. Do.   Broward Florida. D
o.   Greenville South Carolina.
http//minerals.usgs.gov/minerals/pubs/commodity/v
ermiculite/vermimyb05.pdf
25
TABLE 3 ESTIMATED EXFOLIATED VERMICULITE
SOLD OR USED IN THE UNITED STATES, BY END
USE 1 (Metric tons)     200
4   2005   Aggregates2 24,300 22,300 Insulation
3 W   W   Agricultural Horticultural 22,20
0 24,600 Soil conditioning 22,800 W Fertilize
r carrier W   W   Total W W Other4 9,830
  12,500   Grand total5   90,000   85,000   W
Withheld to avoid disclosing company proprietary
data included in "Grand total." 1Data
rounded to no more than three significant digits
may not add to totals shown. 2Includes
concrete, plaster, and premixes (acoustic
insulation, fireproofing, and texturizing
uses). 3Includes loose-fill, block, and
other (high-temperature and packing
insulation and sealants). 4Includes various
industrial and other uses not specified. 5Rou
nded to two significant digits because of
estimated data.
http//minerals.usgs.gov/minerals/pubs/commodity/v
ermiculite/vermimyb05.pdf
26
Vermiculite- Geologic description

• Most mines today are deposits that were formed in
  the pre-Cambrian and Archean (1.5-3.0 billion
  years ago).
• Palabora region, South Africa
• Northwestern corners of China
• Eastern Appalachian range in U.S. (Virginia and
  South Carolina)
• Younger deposits are Triassic in age (225million
  years ago)
• Libby, Montana deposit

(Kogel et al., 2006)
27
Vermiculite- Geologic description

• The formation of vermiculite is basically the
  supergene alteration of biotite at near surface
  conditions. (Hindman, 2006)
• When biotite turns into vermiculite, there is a
  10 to 40 volume increase of particle size.
  (Hindman, 2006)
• It will not form as a primary mineral, and it is
  not stable under hydrothermal conditions. (Roy
  and Romo, 1957)

28
Vermiculite- Exploration

• Near surface
• Large grain size for commercial criteria-look at
  structures that contain large biotite crystals
• Ultramafic intrusives Coarse-grained
  pyroxenites metamorphic bodies with biotite
  schists and gneisses.

(Hindman, 2006)
29
Vermiculite- Exploration
Bush (1976) Three Classes Type 1 deposits in
large ultramafic intrusions such as pyroxenite.
These are often zoned. (Libby, Montana and
Phalaborwa, Republic of South Africa) Type 2
deposits formed in smaller ultramafic intrusions
(dunite, peridotite, and unzoned
pyroxenite). (North Carolina) Type 3 deposits
formed from metamorphic rocks (biotite schists
and amphibole schists). (Enoree, South Carolina
Elk Gulch, Montana most deposits in Colorado,
Nevada, Texas, and Wyoming.)
Borovikov (1962) Four Groups Group 1 deposits
in ultrabasic and alkaline rock complexes. (Major
deposits at Kovdor and Buldym in Russia.) Group
2 deposits in altered carbonate rock. Group 3
occurrences in reaction zones of pegmatites,
talc, corundum, asbestos, and other deposits, and
also in metasomatic veins in serpentines. Group
4 deposits and occurrences in micaceous gneisses
and other metamorphic rocks.
(Hindman, 2006)
30
Vermiculite- Health Risks?

• There are no health risks known for general
  handling and exposure to vermiculite.
• Vermiculite was found with the asbestiform
  amphibole minerals of the Rainy Creek vermiculite
  ore body near Libby, Montana. Health issues
  associated with the asbestos and former mine
  workers resulted in shutting the Libby mine down
  (1921-1990).

(Hindman, 2006)
31
http//www.fafard.com/
32
References

• Bush. 1976. Vermiculite in the United States.
  Pages 146-155 in 11th Industrial Minerals Forum.
  Special Publication 74. Montana Bureau of Mines.
• Borovikov, P.P. 1962. Genetic types, conditions
  of formation and economic evaluation of
  vermiculite deposits. Pages 139-176 in Perlite
  and Vermiculite (Geology, Exploration and
  Production Technology.) Edited by V.Kh. Daragan.
  Translated from Russian. New Delhi Indian
  National scientific Documentation Centre.
• Conrad Fafard, Inc. http//www.fafard.com/
  (accessed March 26, 2007)
• Hoben International. http//www.hoben.com/vermicul
  ite/index.htm (accessed March 2, 2007)
• Hindman, James R. 2006. Vermiculite Industrial
  Minerals and Rocks Commodities, Markets, and
  Uses. Society for Mining, Metallurgy, and
  Exploration, Inc.
• Ks Chimney. http//www.kschimney.com/store/produc
  t.php?pid333pdetail (accessed February 28,
  2007
• Kogel, Jessica E., Trividi, Nikhil C., Barker,
  James M., and Krukowski, Stanley T. 2006.
  Industrial Minerals and Rocks Commodities,
  Markets, and Uses. Society for Mining,
  Metallurgy, and Exploration, Inc.
• Potter, M. J., 2007. U. S. Geological Survey
  Minerals Yearbook-2005 U. S. Department of the
  Interior. http//minerals.usgs.gov/minerals/pubs/c
  ommodity/vermiculite/vermimyb05.pdf (accessed
  February 13, 2007)
• Roy, R., and L.A. Romo. 1957. Weathering studies.
  1. New data on vermiculite. Journal of Geology
  65603-610.