PDF Publication Title:
Text from PDF Page: 003
5,494,513 12 ZEOLITE-BASED LIGHTWEIGHT CONCRETE PRODUCTS BACKGROUND OFTHEINVENTION 1. Field of Invention The present invention relates to lightweight concrete products, and more particularly, to such products where zeolite is a major component; and in one aspect, to a zeolite-based binding material for use in hazardous waste stabilization. 2. Description of Prior Art Conventional lightweight concrete products are made of Portlandcementand/orlime,togetherwithslag,pulverized fuel-ash, and other siliceous ?ne aggregates. Air or other gas (usuallyhydrogenfromthereactionofaluminumpowderin lime water) is introduced into a slurry composed of these materials to produce aerated or cellular concrete products. A uniform cellular structure is formed when the mixture sets. Autoclave curing is generally necessary if lightweight con crete products are to be produced with an acceptable level of strengthandproductionyield. at 70° C. for 5 hours. A relatively larger amount of zeolite, upto50% byweightoftotalcementingmaterialwasused in production of lightweight concrete (JP5-294749 and JP5-294750).Thedisclosedmaterialcomprisesabout47wt. % zeolite,43wt.% Portlandcement,10wt.% quicklime and 0.07 wt. % aluminum powder. Aluminum powder, a conventional foaming agent in the production of aerated concrete, was stil used in these two patent applications to providecellularstructureinthelightweightconcrete.Zeolite functioned therein only as a siliceous material in the con crete composition instead of silica powder or ?y ash gen erally used in conventional aerated concrete production. Utilization of natural zeolite in the production of aerated concrete was reported in “Properties of zeolite as an air entrainingagentincellularconcrete”,Cement,Concreteand Aggregates, CCAGDP, Vol. 14, No. 1, pp. 41-49, Naiqian Feng, 1992. The natural zeolite was calcined at about 500° C. for 2 hours. The particle size of the zeolite used was less than 1.2mm. The suggested mix proportions were 31-48 wt. % ordinaryPortlandcement,19-38wt.% zeoliteand30-38 wt.% water.Thecompressivestrengthofaeratedconcrete after moist-curing at 20° C. for 28 days was in the range of 4.1to5.3MPa anditsdrydensitywasintherangeof750 to850kg/m3. Zeolite has been used as an industrial adsorbent in haz ardous waste treatment. The trapped ions in some natural zeolite products include NH4, Cu, Pb, Zn, Cd, Sr and Cs. Naturalzeolitehasbeenutilizedinlarge-scaleionexchange processes to concentrate and isolate radioactive strontium andcesiumfromwastestreamsofnuclearfacilities(see, “Zeolitic extraction of cesium from aqueous solution” Unclassi?ed Report HW-62607, US Atomic Energy Com mission, 23 pp., L. L. Ames, 1960). Studies involving natural zeolites as collectors of radioactive wastes have been andarebeingcarriedoutinFrance,Italy,GreatBritain, Hungary, Bulgaria, Mexico, Canada and Japan (see “In?u ences of clinoptilolite on Sr-90 and Cs-137 uptakes by plants” Soil Science, Vol 114, p.149, H. Nishita and R. M. Haug, 1972).Itwas alsoreportedthatnaturalzeolitecanbe usedinamobileexchangeunittosuccessfullyremove97% of ammonium from sewage streams and agricultural e?lu ents (see, “Ammonia removal from secondary e?luents by selectiveionexchange”,WaterPollutionControlFederation Journal, Vol. 42, p. R95, B. W. Mercer, 1970). An alkali activated-slagbasedbindingmaterialcontaining10-30% zeolite by weight of slag has been reported for the stabili zationofstrontiumandcesiumions(see,“Immobilizationof simulatedhighlevelwasteintoAASC wasteform”Cement andConcreteResearch,Vol24,p.133,X.Shenetal.,1994). Low leach rates of about 10-5 and 10-6 gIcmZOday for Cs and Sr ions respectively were obtained when the equivalent CszO or SrO content was about 25% by weight of the bindingmaterial. It has been reported that ettringite, hydrated calcium sulphoalurninate which has a structure Ca6[Al(OH)6] 2(SO4)326H2O, can form from A1203’~ of the pozzolans when sulphate and calcium exist in the hydration system. The rate of ettringite formation from pozzolans is notably superior to the rate of ettringite formation from C3A of the Portlandcement(see“EttringitefromPortlandcementori ginandetringitefrompozzolanicorigin:analogies,di?’er ences and semiquantitative relations with their respective origins: interrogations”, 9th international congress on the chemistry of cement, p.343, R. Talero, 1993). Ettringite is wellknownbothasamanuallyoccurringmineralandinthe technology of cements as a product of the reaction of calcium sulphate with the calcium alurninates in aqueous Zeolite powder can be made by grinding either synthetic zeolite or natural zeolite minerals. Zeolite powder can be 25 pre-treated depending on the application. A hydraulic cement is a dry powder which, upon mixing with water, sets and becomes a hardened solid mass forming a water-resis tant product. Lime contains mainly calcium oxide or cal cium hydroxide. Zeolite is a porous silicoaluminate mineral. It has a very large surface area generally greater than 20 rnzlg. Its solid surface can be activated to have high surface energy after calcinationattemperaturesgreaterthan400°C.When35 subsequently immersed in water, the surface generates a large amount of air and heat due to adsorption. This heat increases the temperature of the air in pores or adsorbed on the surface of zeolite particles. The expansion of the air volumeresultsinfoamingandvolumeexpansionoffresh40 concrete during the mixing and pre-storage periods. In addition to its foaming function, zeolite can also react with calcareous materials to form calcium silicoaluminate hydrates which contribute to the strength of the concrete. Thereforezeolitehasthepotentialforuseasabasicraw 45 material to produce aerated concrete. The use of zeolite minerals in Portland cement to increase strength and decrease porosity has been described in PCT Int.Appl.W0 9217,413,toR.S.Chase.TheChasepatent application indicates that zeolite, as do other SiO2-contain~ ing materials, has the pozzolanic activity required to con tributestrengthofPortlandcement-basedcementitiousbind ers. No claims for other uses of zeolite (e.g., its air generatingcapabilities)differentfromthoseofconventional pozzolanicmaterialssuchas?yash,slagandsilicafume 55 weremade.A similarpatentwasissuedinU.S.S.R(seeSU 1,738,774, to G. I. Ovcharenko et al., 1992). The Ovcharenko patent describes a composition of blended cementcontaining15-30wt.% zeolite,40-60wt.% gypsum and 18-40 wt. % Portland cement. Kureha et al, 1991. According to that disclosure, zeolite was utilizedinrelativelysmallamounts,e.g.,20wt.% zeolite, 80wt.%cementandwater/solidratio0.7.Zeolitewas65 calcined at 500° C. and cooled at —20° C. The aerated concrete had a bulk density of 420 kg/m3 after steam-curing 60 The use of zeolite in production of lightweight aerated building materials has been reported in JP 03 93,661 to S. 30PDF Image | ZEOLITE-BASED LIGHTWEIGHT CONCRETE PRODUCTS
PDF Search Title:
ZEOLITE-BASED LIGHTWEIGHT CONCRETE PRODUCTSOriginal File Name Searched:
US5494513.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |