Ever since spinel MgA1(2)O(4) was proposed as a substitute material for chromium based refractories, manufacturers have been encouraged to seek alternative forms of production. Addition of mineralizers has been widely employed as a method for reducing processing temperatures, which are above 1800degreesC without additives. Mixtures of MgO and A1(2)O(3) (molar ratio 1:1) have been prepared in this work, together with different additions of CaCO3 (up to 30 mol%) in a resistance furnace at 1400degreesC. All formed phases are identified by X-ray diffractometry and microstructures are characterized by scanning electron microscopy. Results show that samples contain mainly the spinel phase with a small amount of calcium aluminates (CaA1(2)O(4) and Ca(12)A1(14)O(33)). The X-ray patterns suggest that calcium compounds as well as spinel are present as mixtures because both, angle peak location and relative intensities are maintained like in the mixtures of powders randomly orientated. This assumption is confirmed by EDX analysis that shows zones in the samples with spinel grains over calcium aluminates. The synthesized spinel has a density of 3.19 g/cm(3) after 5 hours at 1400degreesC.