Desenvolvimento de processo para a obtenção de Cloreto de Berílio a partir do Berilo Mineral

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Process development to recoverf beryllium chloride from beryl Metal beryllium has special properties and it is considered to be a strategic material due to its applications in military and aerospace field. This metal can be extracted from the minerals beryl and bertrandite. In Brazil, the beryl is the unique beryllium source and contains about 11% of the element oxide (BeO). Brazil is the major beryl mineral exporter and does not have enough technology for processing it. In Minas Gerais, beryl is considered as a by-product of northeast and east of the state feldspar mines. The metal has been over valorized in relation to the raw ore, whose sell price is about R$1,00/kg of beryl. A partnership between Rima Industrial and Fundação Centro Tecnológico de Minas Gerais (CETEC) was done to develop a production project of beryllium derivatives from the mineral beryl. This project was named Projeto Berílio. A laboratory for the project development was built in order to fulfill the safety requirements concerning beryllium, due to the high toxicity of its derivates. In principle a field work was carried through and mineral samples of four different places in Minas Gerais and Bahia were retrieved. As long as there is not a standard method for the mineral beryl characterization, different analytical methods cited in the bibliography had been tested. A characterization method was developed in the laboratory and presented better results than the bibliographical methods. A beryllium extraction method was developed as an alternative to the existing commercial methods of extraction (sulphate and fluoride) with sodium carbonate (Na2CO3) as the mineral attacking agent, proven to the most efficient among the tested. The mineral beryl attack conditions have been optimized with the use of Na2CO3 considering the parameters: reagents ratio, applied load and reaction time, which yielded about 92% w/w. A method of beryllium hydroxide (Be(OH)2) obtaining and purification has been developed, with the extraction of about 98% of the impurities and with a great beryllium yield during the process (82%). The purified beryllium hydroxide was dissolved in hydrochloric acid (HCl) and led to dry. The reaction product after dry was beryllium oxide, and not beryllium chloride as expected. This result was confirmed by X-ray diffraction analysis. The process mass yield was calculated in beryllium oxide mass terms (BeO) from the mineral beryl that the obtained resulted was 70%w/w of BeO. Desenvolvimento de Processo para Obtenção de Cloreto de Berílio a partir do Berilo Mineral It is concluded that the developed method is efficient, simple and low cost for high purity beryllium hydroxide and oxide obtaining from the mineral beryl.

ASSUNTO(S)

berilo - tecnologia hidrometalurgia berilo - determinação mineralógica engenharia de materiais e metalurgica

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