After two centuries of the discovery, we now know that there are several types of bauxites, in which mineralogy points to the most appropriate application. In the non-metallurgical industry, bauxites with refractory grades have been applied as raw materials in the production of high-alumina refractories for both shaped and unshaped. The increase in the cost of other sources of high-alumina raw materials has encouraged the refractory producers to find a more cost-effective substitute, such as refractory-grade calcined bauxites (RGB). Nowadays, concerns rise regarding the availability of RGB due to the continuous restrictions taking place in China, which has a 95% market share. This work presents a new RGB of high-alumina content (~85%) from a Brazilian source in which process enabled a technology with high refractoriness.

Refractories have been very important for humankind development enabling the manufacturing of a wide range of materials. Primary industries demanding refractories include the manufacturing of steel, non-ferrous metals, glass, lime, cement, ceramics, petrochemicals and incineration. Refractory grade bauxites (RGBs) are high-alumina materials used as aggregates in shaped and unshaped refractory linings suitable to with stand high temperature heating and a corrosive environment. Despite the wide availability of bauxite ores in the world, few countries can supply a bauxite with refractory grades. Guyana, China and Brazil have emerged as suppliers for the refractory industry and the peculiarities of each bauxite from these countries impact directly on the refractory performance.

Resumo Materiais a base de caulim, feldspato e quartzo encontram variadas aplicações na indústria cerâmica, principalmente em formulações de porcelanas e materiais ligados à construção civil, mercados em que o Brasil é destaque internacional. As grandes reservas de rocha potássica e fonolito na região de Poços de Caldas-MG, apresentam-se como potenciais substitutos ao tradicional feldspato devido ao alto caráter fundente. Em adição, argilas desta mesma região também são alternativas frente ao consumo de caulim, substituindo-o parcialmente ou totalmente em formulações cerâmicas. Este estudo apresenta a validade destas alternativas, apresentando formulações cerâmicas e matérias-primas com potencialidades tecnológicas.