Cement makers eye recycled gypsum.A representative from the Portland Cement portland cement Binding agent of present-day concrete. It is a finely ground powder made by burning and grinding a limestone mixed with clay or shale. Its inventor, Joseph Aspdin (1799–1855), patented the process in 1824, naming the material for its resemblance to the Association (PCA (tool, programming) PCA - A dynamic analyser from DEC giving information on run-time performance and code use. ), Skokie, III., says the industry is still looking at the use of recycled gypsum gypsum (jĭp`səm), mineral composed of calcium sulfate (calcium, sulfur, and oxygen) with two molecules of water, CaSO4·2H2O. It is the most common sulfate mineral, occurring in many places in a variety of forms. in cement production. "We have to make sure the formulations will work and that the quality of our product will be maintained," says Lionel LeMay of the PCA. LeMay spoke at a press conference held by the PCA at the U.S. Green Building Council's annual exposition, held in Pittsburgh in mid-November. Cement formulations were the main subject of the event, as PCA announced that the cement industry was working to change its ASTM-controlled formulation to allow as much as 5 percent ground limestone in its final product. This will allow the industry to reduce the amount of material it sends through its kilns by an equal percentage, saving energy and reducing greenhouse gas greenhouse gas n. Any of the atmospheric gases that contribute to the greenhouse effect. greenhouse gas emissions. |
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