Benefits of using Zeolite in Cement and Precasting Applications
- Zeolite has been found to be an excellent pozzolan (Portland cement substitute) in concrete.
- Lightweight aggregate, high strength
15-40% of the cement can be effectively replaced by zeolite
- ZeoStore™ zeolite is 50% lighter than sand, providing a significant increase in bulk materials per ton
- Its particle sizes are less coarse than sand, thereby zeolite spreads easier and provides a smoother concrete surface with no clumping.
- Improved resistance to chemical attacks by salts on concretes used in desert soils, greater resistance to corrosion by soils high in sulfate
- More energy efficient than producing Portland cement
- Ten tons of zeolite used as pozzolan saves about 1 ton of fuel
- Environmentally friendly
Uses of Zeolite with Cement:
Precast walls, Concrete Siding, Flatwork, Highways, Roof Tiles, Blocks, Mortar, Stucco, Mass footings, Sculptures, etc.
Research Study: Clinoptilolite as a Pozzolan
Chemical Spill & Hazardous Waste
The cation exchange capability of zeolite makes it a good candidate for the cleanup of soluble metals such as mercury, chromium, lead, zinc, arsenic, molybdenum, nickel, cobalt, antimony, calcium, silver, uranium, and many others.
Zeolite has a high surface area and large internal void space which provides for superior adsorption. It also has the highest cation exchange capacity available with particular affinity of many hazardous materials, particularly oil substances and heavy metals.
Typical applications would include acid mine drainage, smelter slag, storage batteries and waste, metal contaminated blast sand, oil refinery sludge, mine tailings, metal plating sludge, leach residues and contaminated soils.
Zeolites have uses in advanced reprocessing methods, where their micro-porous ability to capture some ions while allowing others to pass freely allow many fission products to be efficiently removed from nuclear waste and permanently trapped. Equally important are the mineral properties of zeolites.
Their aluminosilicate construction is extremely durable and resistant to radiation even in porous form. Additionally, once they are loaded with trapped fission products, the zeolite-waste combination can be hot pressed into an extremely durable ceramic form, closing the pores and trapping the waste in a solid stone block. This is a waste form factor that greatly reduces its hazard compared to conventional reprocessing systems.
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 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
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. Finely crushed zeolites are used in sorbent barrier layers. Exact specifications are dependent upon the engineered permeability of the system.
Beneficial qualities include:
- High cation exchange capacity
- Low cost
- Large Tonnage Reserve
Oil Spill & Organic Cleanup
Granular ZeoStore™ zeolite can be used to clean up oil spills and gasoline. It efficiently absorbs and deodorizes fluids including oil, gasoline, possibly methyl tertiary butyl ether (MTBE), polychlorinated biphenyls (PCB's), alcohol, water, and a wide variety of other organic and inorganic fluids.
ZeoStore™ zeolite is used in shops, service stations, airports, refineries, machine shops, and petroleum transfer stations.
Zeolite also may be used for cleaning driveways, chemical spills or any liquid contaminated areas. Material is spread on the floor and then swept up. It is not flammable after absorbing oil or gas.
Marine Oil Cleanup
ZeoStore™ zeolite particulate can be dispersed on water to encapsulate surface oil where it can be efficiently “skimmed” after it has been encapsulated. The surface oil or the coagulated mass can be allowed to settle to the bottom where it will not leach out into the water.
Reportedly, the zeolite is not flammable after absorbing the oil or gas. After certain preparation and activation a zeolite can be made to float on water and can be used for marine and inland waterway oil spills cleanup.