Zeolite

Natural & Synthetic Zeolites

• Zeolite Key Words: 

Zeolites, natural zeolites, synthetic zeolites, zeolite minerals, zeolite ore, clinoptilolite, mordenite, blue river white calcite, stilbite, phillipsite, heulandite

• Zeolite Description:

Zeolite is a group of natural or synthetic hydrated aluminosilicate minerals which contain alkali and alkaline metals. It is characterized by a framework structure that encloses interconnected cavities occupied by ion-exchangeable large metal cations and water molecules permitting reversible dehydration. Zeolite is recommended in detergent manufacturing for the applications of the removal of hardness and heavy metal ions and neutralization of acid waters, high cation exchange, gas absorption and water retention capabilities. Their large effective surface area gives them superior adsorptive qualities.

• Zeolite Options Available Available:
  
          a) Natural zeolite
          b) Synthetic zeolite
   
• Zeolite Nominal Chemical Properties Available:

Si0₂= 61 to 67%, Al₂0₃ = 11 to 12.4%, Fe₂0₃ = 4.30 to 6.98%, Ca0= 2.52 to 3.24%, Na₂0= 1.66 to 1.79%, K₂0= 1.85 to 2.07%, Mg0= 1.54 to 1.64%, LOI= 8.41 to 9.30%

• Zeolite Standard Granulations Available:

a) Minus 6 plus 40 mesh
b) Minus 40 plus 80 mesh
c) 80 mesh and finer
d) 100 mesh and finer
e) 200 mesh and finer

• Zeolite Physical Constants:

Specific Gravity (g/cc)	2.10 to 2.47
Apparent Density (g/cm3)
Loose Bulk Density (g/cm3)	0.80 to 0.90
Packed Bulk Density (g/cm3)	1.0 to 1.12
Boiling Point (°C)
EINECS NO.	215-283-8
Thermal Conductivity (cal/s-cm-°C)
Moisture Content	<3.09%
Water Absorption (ml/100g)	45 to 75
Color	Light brown
pH Units (25% slurry)	4.85 to 5.45

 

• Zeolite Typical Applications:

Odor control, industrial absorbents, industrial fillers, gas absorption, soil remediation, wastewater filtration, flocculating agent, animal feeds, hydroponics, molecular sieves, catalysts, desiccants, lightweight concrete, acoustics, ceramics, 

Uses of Zeolites

The uses of zeolites derive from their special properties: They can interact with water to absorb or release ions (ion exchange); they can selectively absorb ions that fit the cavities in their structures (molecular sieves); they can hold large molecules and help them break into smaller pieces ( catalytic cracking). Zeolites are used as water softeners, to remove calcium ions, which react with soap to form scum. The water is filtered through a sodium-bearing zeolite, which absorbs the calcium and releases sodium ions into the water. When the zeolite can absorb no more calcium, it may be recharged by flushing it with brine (a saturated sodium chloride solution), which forces out the calcium ions and replaces them with sodium. At the Hanford Nuclear Facility in Richland, Washington, radioactive strontium-90 (Sr ⁹⁰ ) and cesium-137 (Cs ¹³⁷ ) have been removed from radioactive waste solutions by passing them through tanks packed with the natural zeolite clinoptilolite. Zeolites have also been used to clean radioactive wastes from the Three Mile Island nuclear power plant site and elsewhere. In addition, clinoptilolite is used to clean ammonium ions (NH ₄ ⁺ ) from sewage and agricultural wastewater.

Sulfur dioxide (SO ₂ ) is a pollutant produced by burning high-sulfur coal. It is a major cause of acid rain . Natural zeolites are the most effective filters yet found for absorbing sulfur dioxide from waste gases. As efforts to improve air quality continue, zeolites can be used to help purify the gases from power plants that burn high-sulfur coal from the Ohio River Valley and other regions.

Industrial applications make use of synthetic zeolites of high purity, which have larger cavities than the natural zeolites. These larger cavities enable synthetic zeolites to absorb or hold molecules that the natural zeolites do not. Some zeolites are used as molecular sieves to remove water and ni trogen impurities from natural gas. Because of their ability to interact with organic molecules, zeolites are important in refining and purifying natural gas and petroleum chemicals. The zeolites are not affected by these processes, so they are acting as catalysts. Zeolites are used to help break down large organic molecules found in petroleum into the smaller molecules that make up gasoline, a process called catalytic cracking. Zeolites are also used in hydrogenating vegetable oils and in many other industrial processes involving organic compounds.

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