Title: Chromium (III) Pigments: Use of Leather Wastes as Alternative Starting Material
Abstract: Chromium containing leather wastes poses potentially significant challenges to the ecosystem when disposed of in landfills or when incinerated in the open. An attempt to recover chromium from such leather wastes so as to reduce the chromium that ends up in the landfill was studied. A method of recovery of the chromium in chromium tanned leathers by controlled closed furnace incineration and by employing the protein matrix as an energy source as well as a template for chromium(III) oxide synthesis is detailed. This method provides the advantage of reducing the chromium residues from the leather industry while producing chromite ore ultimately useful in the preparation of pigmented coatings. The dry pigment obtained was green colored and could be further processing and formulating as a pigmented coating (paint). When the chrome shavings were mixed with iron sulfate and then incinerated, a brown colored paint coating was achieved. The best conditions for zero generation/discharge of hazardous chromium(VI) were determined. The pigments developed were characterized in detail by XRD and SEM-EDAX. Photon correlation spectroscopy measurements indicate that the calcined pigments prior to further size reduction were in the range of 300-400 nm.RESUMENResiduos de cuero que contengan cromo presentan significantes potenciales retos al ecosistema cuando sean dispuestos en rellenos sanitarios o incinerados al aire libre. Un intento de recuperacion del cromo de tales desperdicios de cuero se estudio para asi lograr reducir el cromo que termina en tales rellenos. Un metodo de recuperacion de cromo del cuero al cromo por medio de una incineracion controlada en un horno cerrado y empleando la misma matriz proteinica como la fuente energetica, asi como un molde de sintesis del oxido de cromo (III) es detallado. Este metodo provee la ventaja de reducir los residuos de la industria del cuero mientras produce el mineral de cromita, util al fin y al cabo, en la preparacion de pinturas pigmentadas. El pigmento seco obtenido era verde y podria ser adicionalmente procesado y formulado como un acabado pigmentado (pintura). Cuando las rebajaduras se mezclaron con sulfato de hierro y luego incineradas, se obtuvo una pintura color pardo. Las optimas condiciones para obtener cero produccion/descarga del peligroso cromo (VI) se determinaron. Los pigmentos desarrollados se caracterizaron detalladamente por medio de XRD y SEM-EDAX. Espectroscopia por correlacion de fotones determino que los pigmentos calcinados, antes de moler, tenian un rango [de dimension] de 300-400 nm.
Publication Year: 2011
Publication Date: 2011-07-01
Language: en
Type: article
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Cited By Count: 4
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