Magnesium sulfate is characterized as a possible co-product of some Hydrometallurgical Processes involving mineral concentrates that has this metal when subjected to leaching involving sulfuric acid. In the context of the processes flowchart, a fairly common step is the neutralization of the solution that usually takes effect through the solubility of calcium oxide. This, in turn, can be substituted for magnesium oxide as long as these properties, such as contact surface and reactivity, are suitable for the requirements of this step. Thus, the thermal decomposition process of magnesium sulfate, apparently, it is not configured as a possible processing route because it occurs at a temperature of approximately 1100 Celsius degrees, significantly elevated for the formation of a magnesium oxide which satisfies the conditions necessary for a neutralization efficient. The thermodynamic study suggests that in the presence of reducing agents such as carbon, a decrease in the temperature occurs to approximately 400 Celsius degrees, where the conversion of sulfate to magnesium oxide is theoretically viable. Thus, the objectives of the research work are associated with an evaluation of the behavior of the reactive system constituted by MgSO4 when in the presence of carbon provided from the charcoal. The study also contemplates the characterization of the materials obtained in order to verify the attainment of MgO and to evaluate how the properties of the material are suitable for their use as a pH regulating agent such as CaO. Thus, in addition to the techniques of scanning electron microscopy and X-ray diffraction, it is also expected the quantification of the reactivity of the product in acidic solutions. The analyzes performed with the variables, excess of reducing agent, temperature, drag flow and homogeneity of the sample, showed that temperature is the variable that most influences the decomposition of MgSO4. Among all the analyzed tests, the experiments at 900 Celsius degrees and with 25 and 30 minute were that indicated the best experimental results of conversion, reaching a conversion close to 100 percent. The characterization analyzes, in DR-X and MEV/EDS, indicated that MgO was formed at the end of the reaction. The reactivity test indicated that the obtained MgO can be used as pH regulator, attending the work proposal.