Sintering and crystallisation of a borosilicate glass and the effect of alumina addition. Preparation of glass powders by melting, crushing, milling and sieving. Preparation of compacts powders and sintered samples by mixture, pressing, and heating treatments. Characterisations of powders and sintered samples (size distribution, surface area, density, infra red, differential thermal analysis, thermogravimetry, differential scanning calorimetry ,viscosimetry, thermomechanical analysis, thermodilatometry, scanning electron microscopy, Xray diffraction and energy dispersive by Xray. Determination of the activation energies for viscous flow, nucleation and sintering. Application of some models (Frenkel and Scherer) to describe the densification rate of the glass powder compacts during the sintering stage. Ecomaterials. Recycling of Stones Powders by Ceramic Processing. Recycling of Coal Fly Ash by Ceramic Processing. Recycling of Scrap of the Electrical and electronic Industries.