Natural Zeolites are the least-known treasures for environmental pollution control, separation science and technology. Natural zeolites are volcanic minerals with unique characteristics. Their chemical structure classifies them as hydrated aluminum silicates, comprised of hydrogen, oxygen, aluminum, and silicon, arranged in an interconnecting lattice structure. The arrangement of these elements in a zeolite crystal gives rise to a honeycomb framework with consistent diameter connecting channels that vary in size depending on the type of

zeolite mineral. This unique structure makes zeolites different from "other" aluminum silicates (kaolin, bentonite, etc.) due to the following special properties:

Oil Absorbents

Zeolite granules can be used as oil absorbents.  Since the granules are white, they can be easily seen when used to make dikes, barriers, or floor coverage around machinery and on shop floors.  

Other applications :  

• Safety Products for Floor Dry

• Odor Control for Animal Waste

• Carrier Granules for Pesticides / Herbicides

• Gas adsorption: the ability to selectively adsorb molecules of gases and vapors;
• Oil absorption : The ability to selectively absorb Oils
• Water absorption/desorption: the ability to reversibly absorb/desorb water without any chemical or physical change in the zeolite matrix;
• Ion exchange: the ability to exchange inherent cations for other cations on a basis of ion selectivity.
• Oils, Acids, Hazardous Materials, Animal Fluids, Grease, Cooking Oils, Brake Fluid, Liquid Pesticides, Antifreeze, Power Steering Fluids, Transmission Fluid, Gasoline, Diesel Fuel, Battery Acids, Chemical Spills, Solvents, Paint Thinner, Petroleum Distillates, Hydraulic Fluid, Bio-Hazardous Waste, etc.

Zeo-Tech, in association with Jack Spratt Industries has pioneered numerous beneficial applications for natural zeolites. The applications are in the form of development, demonstration and development of engineered systems that result in huge savings in capitol and operating costs. A few examples of the beneficial applications are as follows:

WASTEWATER TREATMENT AND SEWAGE

Ammonia is a major issue for the treatment of municipal wastewater. Ammonia levels in municipal wastewaters can be reduced to 10-15 ppm through traditional primary and secondary treatment facilities. Final circulation in the tertiary treatment stage is accomplished with polishing filters containing Laumontite, a popular form of natural zeolite. The zeolites lower the level of ammonium to non-toxic, acceptable levels. The zeolite beds can be regenerated and recycled indefinitely.

Significant properties include:

• High cation exchange capacity

• Selectivity for ammonium cations

• Regeneration capability

The size of zeolite used in wastewater polishing filter columns varies according to the design. A size specification of -20 to +35 Tyler mesh is typical for this application.

METALS REMOVAL - MINE WASTEWATER TREATMENT

Zeolites are highly selective scavengers of a variety of metal cations that can be removed from liquid effluents through the process of ion-exchange. These cations include lead, silver, cadmium, cobalt, zinc, copper, mercury, magnesium, iron, aluminum, chromium and others. Laumontite water polishing treatment systems are applicable in industries such as mining, electroplating and electronics. Giant industrial houses, like IBM, have deployed this application for treatment of wastewater containing heavy metals.

Significant properties include:

• High cation exchange capacity

• Selectivity for many metals

• Low cost relative to resins or synthetic zeolites

• Capacity for regeneration

Specifications are highly variable according to the end use. Pilot-scale studies are recommended to determine the appropriate zeolite product for a site specific waste stream.

RADIOACTIVE WASTE TREATMENT

Process effluents bearing radioactive isotopes can be treated through columns packed with natural zeolites. The zeolites selectively remove cesium (Cs134, CS137) and Strontium (Sr90) isotopes through the process of ion-exchange. Effluent liquids are purified to acceptable limits for discharge as the radioactive isotopes are held within the zeolite cage structure. One outstanding example of the application is the British Nuclear Fuels, Ltd. Site Ion Exchange Efficient Plant (SIXEO) at Sellifield, England. The other large application is for the treatment of low level liquid effluents at the DOE West Valley, NY site, where Phillipsite was used to selectively remove CS137 and SR90 isotopes. The permanent storage or disposal of the waste is facilitated by the inorganic and stable structure of the zeolite which can be encapsulated in cement or glass.

Significant properties of zeolite in this application include the following:

• High cation exchange capacity

• Selectivity for cesium and strontium

• Radiation Stability

• Resistance to mechanical attrition

• Cost Effective relative to other methods

These zeolites are produced with the high quality assurance.  The most common Minerals zeolites in service today include (laumontite, clinolite betonite etc.), The decontamination factors achieved by these products often exceed expectations.

SORBENT BARRIERS FOR RADIOACTIVE WASTE

Permeable barriers incorporate sorbent materials, including zeolite, to selectively contain contaminants that are percolating from shallow land burial sites of low-level radioactive waste. The zeolites are combined with clays and other materials that retard the migration of leachate for a period long enough to allow exchange and/or decay of radioactive ions.

Beneficial qualities include:

• High cation exchange capacity

• Low cost

• Large tonnage reserves

Finely crushed zeolites are used in sorbent barrier layers. Exact specifications are dependent upon the engineered permeability of the system.

FILLERS

Zeolites are used extensively in Japan as fillers in the manufacture of paper These filler grades of zeolite have a large potential for utilization in the paint and plastics industries. Many deposits of natural zeolites contain high-brightness reserves and the potential for benefaction is increasing with improved technology for magnetic separation and bleaching of zeolite.

POLLUTION CONTROL

Natural zeolites are an adsorbent of choice for many cost effective air pollution control technologies treating the hazardous air pollutants (HAP) and listed volatile organic compounds (VOC). The need for technologically improved air purification systems has been indicated by keen client interest in the use of zeolites in controlling indoor air pollutants or "sick building syndrome". Existing filtration systems typically contain activated carbon as the adsorbent media. Because most grades of activated carbon contain large internal pores, they tend to trap a wide variety of larger molecules. Zeolites, on the other hand, contain a very small internal pores, in all cases from 3 to 5 angstroms. For this reason zeolite is a highly selective adsorbent of specific gas-phase molecules and elements. Many of the identified indoor air pollutants, including formaldehyde, chloroform, ammonia and carbon monoxide, are in a size range that is most effectively sieved by zeolite. Many promising zeolite and zeolite/carbon air purification and odor controlling systems are being developed to meet the need.

Beneficial qualities include:

• Selectivity for pollutant gases of concern

• Inexpensive relative to other molecular sieves

GAS PURIFICATION AND SEPARATION

Because zeolites possess the ability to act as molecular sieves, they are used to purify or sweeten natural gases through the removal of impurities such as carbon dioxide, sulfur dioxide and water. In addition to upgrading natural gas, zeolites are used to separate oxygen and nitrogen in pressure swing adsorption columns. These utilizations of natural zeolites are most common in Japan, as most domestic gas purification and separation is done with high-cost synthetic zeolite molecular sieves.

HEAT STORAGE AND SOLAR REFRIGERATION

The high heat of adsorption and ability to hydrate and dehydrate while maintaining structural stability have been found to be useful in various heat storage and solar refrigeration systems. A hydroscopic nature coupled with an inherent exothermic reaction when taken from a dehydrated to a hydrated form (heat of adsorption), make natural zeolites effective in the storage of solar and waste heat energy.

MODIFIED NATURAL ZEOLITES

A variety of products have been formulated wherein zeolites are pelletized and/or activated for utilization in specific applications. Some of these products include:

• Manganese coated zeolites used in home water softening and purification units

• Air dryers for compressed air brake systems

• Insulated window desiccants

• General packaging and food desiccants

• Moisture absorbents in automotive mufflers

• Moisture absorbents in refrigeration systems

FOR MORE INFORMATION . . .

The previous description of natural zeolites begins to outline the tremendous potential of this unique mineral. There are other uses not listed here which further utilize the benefits of this material's unusual mix of properties. The cost effectiveness of natural zeolites in retrofit designs and newly developed systems will push them to the forefront of state of the art technologies. Our zeolite product can be applied in a variety of uses ranging from single low tech systems to intricate high tech designs.

Home | Agricultural | Aqua-cultural | Landscape | Industrial | Testimonials | F.A.Q. | Shipping | e-mail