The conversion of Bolivian clays and feldspars to the valuable zeolites LTA, FAU thus represents a potential major income for the Altiplano and el Chapare regions of Bolivia. Recently, the preparation of zeolite/clay composite membranes has been described in the literature. These quite technologically sophisticated materials can be used for separation of alcohol water mixtures by pervaporation. The following research tasks will be carried out: The first part of this subproject is a detailed chemical, physical and structural characterization of the raw materials in the form of clays and feldspars from the Altiplano and Chapare. This is a minor part of the work. The following methods will be used:
Determination of chemical composition of the materials down to trace levels by ICP-MS and micro analysis by EDS. Thermo gravimetric analysis (TGA) with differential scanning calorimetry (DSC) will be used as a complement.
The crystalline structure of the materials will be determined by XRD.
The morphology of the materials will be determined by SEM.
The porosity and surface area of the materials will be determined by nitrogen adsorption.
Particle size (Cilas).
After completed characterisation of the raw materials, synthesis methods to convert the Bolivian kaolin and feldspars to LTA and FAU zeolite will be developed. To the best of our knowledge, there are no publications describing this in the scientific literature. The synthesis of zeolites from feldspars is unproven, and may be difficult. Furthermore, a demonstration of the feasibility to synthesize these zeolites from Bolivian kaolin is a first important step before future industrial production of zeolites in Bolivia. After synthesis of the materials, they will be evaluated in some (lab-scale) applications. The use of the prepared zeolites in some of the applications mentioned above such as catalysis and ion-exchange will be demonstrated.