The exploitation of deposits and more particularly the silica sands has become an important activity for the industrial development (manufacture of glass, pigments and silica gels) considering the increased consumption of these substances in the industry. While their uses are subject to specific criteria according to well-defined standards.
World production of silica sand for the needs of the industry is about 140 Mt / year: United States (24%), the Netherlands (20%) and France (5%). The price of silica sand varies according to its characteristics (such as particle size and purity). The silica sands cost 35 dollars/tones, while the price of extra-silica sands can reach 40 dollars/kg.
Global reserves of silica sands are important and represent more than a century of consumption at the current rate of production. In Tunisia, there are large deposits of silica sands. These materials have an economic significant interest. Indeed, the consumption of silica sands in Tunisia has not ceased to increase given the large quantity of silica sands imported from various countries such as: Belgium, France, Germany, Italy, Spain, USA, Mexico ...
In 2015, imports of silica sand were estimated about 11.5 Million USD, (INS, 2016). These imports weigh for the country's trade balance and the deadlines for completion of the various projects. In order to make up for this deficiency in silica sands, several prospecting works have been carried out previously to search for potential resources in these materials [1–5].
Silica gel is an amorphous material with a high adsorption capacity [6]. This material is used as a moisture adsorbent or in the purification of effluents [7–9]. This material has several advantages:
- Easy to regenerate (Silica gel when it becomes saturated can be regenerated by heating at 100 - 120 °C until it returns to its original state);
- Non-toxic, environmentally benign and chemically inert with a high melting point (it is very similar to silica sand and quartz and can therefore be transferred safely by any means of transport).
Recent studies have investigated the versatility of this amorphous material in applications including fillers [10], coatings [11], electronics [12] optics [13], and pharmaceuticals [14]
This work is aimed to promote local georesources (silica sands) for the preparation of silica gel.