The rice husk becomes " Green " the treasure mixes the cement and helps emission reduction
http://www.enorth.com.cn 2009-07-14 10:35
As early as several years ago, the scientists found the rice shell as the potential value of the construction material. The rice shell is rich in oxidizing the silicon (SiO2) two times ,And this composition is the important composition of concrete. People attempted to utilize rice husk dust left after burning the rice husk in the past, substituted materials as the cement, but the rice husk that this kind of method produces is too high in gray carbon content, it is unsuitable to serve as the cement composition.
The researchers found a new rice husk preparation method recently, can be while the rice husk dust is serving as the concrete composition, promote the prosperity of the green construction undertaking.
U.S.A. Texas general promise city of fields lying fallow in rotation (Plano) Service company Chk group of the project (ChKGroup, Inc) President Rajan Patti Wen (RajanVempati) ,Have already cooperated with a research group at present, almost find and make the method without carbon rice husk dust. The new method puts rice husks into the smelting pot, utilize and burn at 800 ¡æ, two that has high purity left finally oxidizes the silicon particle. Recently, Patti Wen and research group are in Park branch school of the university of Maryland (CollegePark) At green chemistry and project meeting held, have shown their result of study.
Patti Wen says: "Though will produce the carbon dioxide while this burn, the whole course is come to see ' carbon is neutralized '. The carbon dioxide discharged will be absorbed and goes back but offsets by the new corn of kind of every year. "(carbon neutralize,carbonneutral, mean let's calculate people oneself carbon dioxide emission which activities produce directly or indirectly daily, and calculate and offset the economic cost that the carbon dioxide needs, then offset the corresponding carbon dioxide amount in the atmosphere through planting trees or implementing other environmental protection projects, in order to achieve the in environment protecting mode goal. )
In fact, the use and consume and inhibit climatic change from bringing the difficult problem of the concrete. Produce a ton of cement used for making the concrete each time, will discharge a ton of carbon dioxide to the atmosphere soon. And in the whole world, cement produce account for all 5% that carbon dioxide discharged that human activity cause.
In recent years, the cement has become the storage storehouse of waste material products of all kinds. From the slag, flying dust of colliery of the steel plant, to silicon dust of the metal industry remainder of silicon, all these are regarded as substituent of portland cement of high carbon content but " lived again ".
American Purdue University (PurdueUniversity) Simple Rec (JanOlek) Say: "The reason why rice husk dust has not become principal ingredients of concrete, usually because its carbon content is too high. If can solve this problem, the rice husk dust will become the good material of concrete, thus reduce the carbon dioxide to discharge exerting oneself for the concrete trade. "
Will resist corrosivity to mix the rice husk dust more firmly and even more in the concrete. Group of this research predicts, while building the skyscraper, bridge, any coastal waters or aquatic building, if can substitute 20% of the cement with the rice husk dust, the concrete advantage made will be embodied greatly.
If the rice husk dust is made the large scale, spend all rice husks which U.S.A. produces can make 2,100,000 tons of rice husk dusts every yearing. In fact, consume very old developing country for China, India rice and concrete but speech, the development potentiality of the rice husk dust is greater.