Avaliação da desidratação do gesso por análise termogravimétrica e difração de raios-x

Abstract

Gypsum is added to the cement clinker while still in factory production to achieve an adequate workability time, since pure clinker has a setting time of a few minutes. It acts as a retarder in the transition phase of the fluid material to its solid state and, for the oil industry, having this more adequate time control is essential as it defines the operating window well in order to carry out a successful cementation step. This work aims to evaluate the effect of temperature on gypsum dehydration using thermogravimetry and x-ray diffraction techniques. We observed that with increasing temperature the gypsum changes its composition, namely: gypsum (a dihydrate compound) → bassanite (also called hemihydrate compound) → anhydrite (no water molecule in its composition). Now would come the results obtained with TG's and DRX.