Vermiculite Definition Minerals with micaceous morphology commonly formed

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, Fe 2+)3 (Si, AL, Fe 3+)4 O 10(OH)2 O 4 H 2 O, Hydrated Magnesium Iron Aluminum Silicate Hydroxide http: //mineral. galleries. com/minerals/silicate/vermicul. htm

Vermiculite - Class • Class: Silicates (Si. O 4) • 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/

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/vermiculite/specs. htm

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 k. J/kg. K. p. H value: 8. 0 -9. 5 Thermal Conductivity: 0. 062 -0. 0656 W/m. K

Vermiculite- Associated Minerals • Corundum • Apatite • Serpentine • Talc • Stellerite • Biotite • Other clay minerals http: //mineral. galleries. com/minerals/

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)

Vermiculite- Typical Chemical Analysis (Hindman. , 2006)

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/

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)

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)

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)

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)

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

Vermiculite- U. S. Occurrences (Hindman, 2006)

Vermiculite- World Occurrences (Hindman, 2006)

Vermiculite- Production http: //minerals. usgs. gov/minerals/pubs/commodity/vermiculite/vermimcs 06. pdf

Vermiculite- U. S. Production and Trade (Hindman, 2006)

Vermiculite- Processing (Hindman, 2006)

Vermiculite- Production Mining Concentrate Drying Concentrate Crushing Ore Transport Concentrate Classifying Ore Storage Concentrate Storage Ore Screening Exfoliating Ore Storage Ore Blending Product Grinding Product Classifying Product Storage Wet Processing http: //www. epa. gov/ttn/chief/ap 42/ch 11/final/c 11 s 28. pdf (Kogel et al. , 2006) Most unexfoliated ore (640 - 1, 120 kg/m 3) 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)

Vermiculite- Exfoliation Vertical furnace: used in United States (Picured below) Rotary drum furnace: (Hindman, 2006) used outside North America 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/exfoliator. html#Anlagenund. Ofenbau

Vermiculite- Crude/untreated http: //www. chinavermiculite. com/verm. htm

Vermiculite- Expanded/exfoliated http: //www. chinavermiculite. com/verm 2. htm

TABLE 2 ACTIVE VERMICULITE EXFOLIATION PLANTS IN THE UNITED STATES IN 2005 Company County State Isolatek International, Inc. Sussex J. P. Austin Associates, Inc. Beaver Palmetto Vermiculite Co. , Inc. Spartanburg P. V. P. Industries, Inc. Trumbull Schundler Co. , The Middlesex Southwest Vermiculite Co. , Inc. Bernalillo Sun Gro Horticulture, Inc. Jefferson Do. La Salle Thermal Ceramics Inc. Macoupin Thermo-O-Rock East, Inc. Washington Thermo-O-Rock West, Inc. Maricopa Verlite Co. Hillsborough Vermiculite Industrial Corp. Allegheny Whittemore Co. , Inc. Essex W. R. Grace & Co. Maricopa Do. Broward Do. Greenville New Jersey. Pennsylvania. South Carolina. Ohio. New Jersey. New Mexico. Arkansas. Illinois. Do. Pennsylvania. Arizona. Florida. Pennsylvania. Massachusetts. Arizona. Florida. South Carolina. http: //minerals. usgs. gov/minerals/pubs/commodity/vermiculite/vermimyb 05. pdf

TABLE 3 ESTIMATED EXFOLIATED VERMICULITE SOLD OR USED IN THE UNITED STATES, BY END USE 1 (Metric tons) 2004 2005 Aggregates 2 24, 300 22, 300 Insulation 3 W W Agricultural: Horticultural 22, 200 24, 600 Soil conditioning 22, 800 W Fertilizer carrier W W Total W W Other 4 9, 830 12, 500 Grand total 5 90, 000 85, 000 W Withheld to avoid disclosing company proprietary data; included in "Grand total. " 1 Data rounded to no more than three significant digits; may not add to totals shown. 2 Includes concrete, plaster, and premixes (acoustic insulation, fireproofing, and texturizing uses). 3 Includes loose-fill, block, and other (high-temperature and packing insulation and sealants). 4 Includes various industrial and other uses not specified. 5 Rounded to two significant digits because of estimated data. http: //minerals. usgs. gov/minerals/pubs/commodity/vermiculite/vermimyb 05. pdf

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 (225 million years ago) – Libby, Montana deposit (Kogel et al. , 2006)

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

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)

Vermiculite- Exploration Bush (1976): Three Classes Borovikov (1962): Four Groups Type 1 deposits: in large ultramafic intrusions such as pyroxenite. These are often zoned. (Libby, Montana and Phalaborwa, Group 1: deposits in ultrabasic and alkaline rock complexes. (Major deposits 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. ) 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.

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)

http: //www. fafard. com//

References: • Bush. 1976. Vermiculite in the United States. Pages 146 -155 in 11 th 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/vermiculite/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. • K’s Chimney. http: //www. kschimney. com/store/product. php? pid =333#pdetail (accessed February 28, 2007 http: //www. kschimney. com/store/product. php? pid=333#pdetail • 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/commodity/vermiculite/vermimyb 05. pdf (accessed February 13, 2007) • Roy, R. , and L. A. Romo. 1957. Weathering studies. 1. New data on vermiculite. Journal of Geology 65: 603 -610. • Vermiculite Home Page for Information about Vermiculite---A Mineral with Many Uses: Naturally Occuring, Safe, and Plentiful. http: //www. vermiculite. net// (accessed February 13, 2007) • The Vermiculite Association. http: //www. vermiculite. org// (accessed February 13, 2007) • Vermiculite (Hydrated Magnesium Iron Aluminum Silicate Hydroxide). http: //mineral. galleries. com/minerals/silicate/vermicul. htm (accessed February 26, 2007) • Yanxi Minerals Co. Ltd. http: //www. chinavermiculite. com// (accessed March 2, 2007) • 77 Hydro. http: //77 hydro-stores. yahoo. net/med 038. html (accessed February 28, 2007)