Navegando por Assunto "Hidrometalurgia"

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Acesso aberto (Open Access)
Estudo da extração de compostos de ferro da lama vermelha visando a extração e/ou recuperação de compostos de titânio
(Universidade Federal do Pará, 2012-04) MAGALHÃES, Edilson Marques; MACÊDO, Emanuel Negrão; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/8718370108324505; http://lattes.cnpq.br/6157348947425968
The main concerns about waste generation are focused on the effects that these materials can have on human health and the environment, since the hazardous waste generated by industries need particular attention and care, because when improperly managed, become a serious threat to the environment. In this context, this work shows the studies for recycling of red mud as raw material to obtain titaniumcompounds. The study covers three hydrometallurgical routes: red mud calcined at 900°C (LV900), red mud without thermal treatment (LV-STT) and red mud sintered in a reducing atmosphere (LV1300). The leaching experiments were performed with temperature values of 60, 80 e 90°C and sulfuric acid concentration of 20 and 30%. Together with the analysis mathematical modeling was carried out leaching process. Such analysis shown that the red mud can be applied as a source of alternative raw material for the concentration and subsequent recovery of titanium compounds. The kinetic modeling of the curves of data extraction as a function of time and the mathematical model developed in this work, shown that, the chemical reaction step describes the leaching tests. The developed model also allowed obtaining kinetic parameters such as activation energy and velocity of chemical reactions of the leaching process.
Acesso aberto (Open Access)
Estudo hidrometalúrgico de compostos de titânio proveniente do resíduo do processo Bayer
(Universidade Federal do Pará, 2012-03-28) QUARESMA, Danielly da Silva; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
Studies performed in the Bayer process residue, red mud, for recycling this material has been intensified by their physicochemical characteristics. The residue has several oxides, these stands out the iron oxide content above 30% by weight and titanium oxide at concentrations above 5% by weight. This work studies the possibility of extracting iron oxide, aiming at concentration of titanium compounds. The extraction was carried through process of calcination of red mud at 900°C followed by acid leaching with concentration of H2SO4 at 20% and 30% by volume at 60°C, 80°C and 90°C, with removal of an aliquot every 30 minutes. During the leaching process, there was intense extraction of iron compounds, resulting in an increased concentration of titanium at the red mud. This was found in all experiments, especially those which were performed at 90°C and H2SO4 at 30% v/v, where was a extraction of 95% iron and concentration of up to 14% titanium considering the global mass balance. From the data obtained, the red mud becomes an interesting material to be used as an alternative source of minerals titanium, which are found in nature with a percentage of around 8%.