Acid activation and bleaching capacity of some Cameroonian smectite soil clays

International audienceThree Cameroonian clay materials with high smectite content were used for decolouration of palm oil with a clay / oil ratio of 2%. Particle size distribution, mineralogical and chemical analyses were done. The activation parameters (temperature, acid concentration and activation time) permitting the optimisation of their bleaching capacities have been determined. Their performances were compared to those of a commercial bleaching earth before and after acid activation

Clays from the Bafang region (West Cameroon): Properties and potential application as decolorizing agent of river water

Woumfo, E. Djoufac Djomgoue, P. Tamfuh, P. Azinwi Bitom, D. Figueras, F. Njopwouo, D.International audienceA clay sample from the Bafang region (Cameroon) was analysed by a number of techniques which Include grain size distribution major and trace element s determination thermogravimetry X-ray diffraction and scanning electron microscopy The clay had an average magnetite content of 20% The fine clay fraction with 25% of the raw material consisted of kaolinite/halloysite and goethite and magnetite as associated minerals The study of decolouration of river waters showed that the clay can be used as adsorbent Amounts of 8-9% discoloured the Nyong River waters from 267 to 33 PtCo colour units When the pH of the water was lowered to 47 with sulfuric acid only 4% clay was required and the colour obtained was 27 PtCo The adsorption of humic substances on the clay was indicated by the IR adsorption bands of the hydroxyl groups Aluminum sulfate used as the reference material was not able to eliminate all humic substances from the Nyong waters When the clay was used as an adsorbent after coagulation by aluminum sulfate 1 5% clay permitted to attain a colouration of 6 PtCo units The settling velocity of the clay particles in the water at 1 5% content was higher than 1 m/h (C) 2010 Elsevier B V All rights reserve