engleski

Zeolite - Cement composite for waste immobilization

Waste solidification in cement materials is an attractive route to immobilize various harmful or toxic industrial byproducts. In order to develop durable cement composite, in this work a number of inorganic additives had been investigated as potential cement matrix modifiers. The waste mud under study is obtained during deep underground water purification in eastern Croatia. It consists mainly of amorphus iron and manganese oxy-hydroxides containing arsenic that is also removed from the water. Materials used for cement composite preparation are: ordinary Portland cement CEM II 42.5N, hydrated lime, natural zeolite consisting mainly of clinoptilolite mineral, waste mud and potable water. A total of 39 samples were prepared and tested after 56 days for its compressive and flexural strength, density, longitudinal and transversal ultrasonic wave velocity. Samples were additionally characterized by X-ray powder diffraction, simultaneous differential thermal and thermogravimetric analysis and also by Fourier transformed infrared spectrometry. Chemical stability tests measured quantity of arsenic leached from the prepared composite. It is shown that volume fraction of starting materials is meaningful parameter to organize and interpret the data measured.

zeolite; cement; waste immobilisation

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