Red mud from zeolite synthesis

Zeolites are a class of crystalline aluminosilicate materials suitable for a variety ofindustrial processes, such as catalytic reactions separations, adsorption and ionexchange, due to their porous and open network structure resulting in a largeeffective surface area zeolite NaA or zeolite A is the synthetic form of sodiumaluminosilicate. Nowadays zeolite A, which is a widely used synthetic zeolite, isused in detergent industry instead of phosphate salts to decrease phosphate pollutionthat has harmful effects on plant and animals.In this study zeolite A has been synthesized by fusion method from red mud which isthe waste of the leaching of bauxide. In the zeolite synthesis method the red mudprecipitates were fused with sodium hydroxide (NaOH) in a 1:1 ratio to obtain ahomogeneous mixture; it was then heated in a nickel crucible in air at 550 ºC for 1 h.Secondly the fusion product was ground and dissolved in distiled water, then 4 mLsodium silicate solution added. The mixture was then crystallised under staticconditions at different temperatures (60, 80 and 90 ºC) and different times (12, 16,20, 24).The mineralogical analysis of the zeolite material produced was performed using X-Ray Diffaction (XRD). Scanning electron microscopy (SEM) was used to determinethe morphology of zeolites, Fourier Transformed Infrared Spectrometry (FTIR) andCation Exchange Capacity (CEC) techniques were used for chemicalcharacterisation. Experimental results have demonstrated that parameters such astime and temperature have a significant effect on degree of zeolitisation achieved.The fusion method yields the best result for 90 ºC and 16 hours.Keywords: Zeolite A, red mud, synthesis, fusion.