Vitrification: an alternative to minimize environmental impact caused by leather industry wastes.

ABSTRACT

The main purpose of this work was the investigation of the immobilization of chromium ion present in the ash from the incineration of chromium-tanned leather shavings (ACS) by means of vitrified ceramic bodies. To achieve the immobilization samples were initially produced adding soda-lime glass to ACS. After that, new formulations were produced with the addition of pure oxides, TiO(2) and MgO, to the soda-lime glass and ACS sample. These samples were conformed by pressing and fired in an eletrical furnace, at temperatures of 750, 800, 950 and 1000 degrees C. The ceramic bodies were evaluated with respect to their physical properties and mineralogical composition by X-ray diffraction and energy dispersive spectroscopy (EDS) mapping. The chromium immobilization was characterized by leaching tests according to Brazilian Regulations (NBR 10005). The results confirmed the immobilization of the chromium ion within the allowed limits of Brazilian Regulations, NBR 10004 (5mg/L), with the use of glass and vitrification/densification agents such as titanium and magnesium oxides.