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Ceramic pigments have been used in the ceramic industry to decorate plates, tiles, floors, and walls, for this reason they are very important in the construction industry. Ceramic pigments are inorganic chemical compounds, which provide color and are insoluble in a medium with which they do not interact physically or chemically [1] .

Ceramic pigments have different crystal structures, such as the spinel structure. Spinel type structures feature high strength, high thermal stability, low sintering temperature and easy incorporation of chromophore ions in the lattice, obtaining different colored pigments [2] - [8] .

Traditionally, the synthesis of ceramic pigments has been led by the conventional ceramic way, but in recent years there has been a rise in the implementation of non-conventional methods. One reason for this is the importance of decreasing the temperature and time of the heat treatment with the corresponding reduction in gas emissions. Most synthesis methods employed are mainly solid-state reaction [9] , sol gel [10] , microemulsion [5] , co-precipitation [11] [12] , hydrothermal [12] [13] , and polymeric precursor method [14] - [17] .

In this work, the methods employed were ultrasound-assisted co-precipitation and high-energy milling.

Co-precipitation is important to avoid many environmental problems related to water resources, concentrations of metals in aqueous systems and technology for wastewater treatment. Co-precipitation varies in each case and the partition in the solid phase can be accomplished by surface adsorption, ion exchange, precipitation of the surface, and formation of occlusion solid solution [18] . A modification of this method is the sonochemical way, which is the use of irradiation with ultrasonic waves [19] .

Mechanochemical synthesis involves high energy milling of the reactants powders; in this case they are oxides. Its effect is to induce or directly activate the chemical reaction in a subsequent heat treatment at a relatively low temperature. Types of high-energy grinding are distinguished by the nature of the reagents and chemicals and the structural changes during the process [20] [21] .