EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
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A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Item Kaolinite removal from bauxite by flotation.(2016) Rodrigues, Otávia Martins Silva; Peres, Antônio Eduardo Clark; Henriques, Andréia Bicalho; Amorim, Bárbara GonçalvesThis paper presents a potential condition to separate kaolinite through flotation when it is present in bauxite ore. This research anticipates a Brazilian industry requirement, considering the tendency towards the need for aluminosilicates removal from bauxite ores, as has already occurred in China. Kaolinite is the most abundant aluminosilicate, and gibbsite is the main aluminum bearing mineral in Brazilian bauxite ores. The first step was a fundamental study involving microflotation experiments with pure samples of kaolinite and gibbsite. Ammonium quaternary salts and amines were used as the collector and corn starch as the depressant. In a fundamental study, the best conditions determined in the first step were evaluated for the flotation of kaolinite from bauxite ore using laboratory scale experiments. Tests with AQ142/starch (pH 10) and CTAB (pH 7) led to satisfactory results. In general, the highest values of alumina/silica mass ratio were obtained with AQ142/starch and the highest values of mass recovery and metallurgical recovery were achieved with CTAB.Item Carbonate content reduction in zinc ore concentrate.(2012) Martins, Lemyr; Peres, Antônio Eduardo Clark; Galery, Roberto; Pereira, Carlos AlbertoThe hydrometallurgical zinc extraction from the willemite concentrate is impaired by the presence of high carbonate content. A stiff froth is produced causing zinc losses and acid consumption. A standard procedure was developed to de ne the acceptable froth layer height in a laboratory test. Froth layers shorter than 2 cm resulted from carbonate content in the concentrate below 10.8%. The feasibility of adding a carbonate otation stage to the circuit was tested in laboratory and pilot scales. Among the collectors investigated, only those presenting a saponi cation degree above 189 mg KOH/mg were effective in the laboratory experiments. Oleine and rice bran oil soaps were selected for the pilot scale experiments. The nal stage was a one month long industrial trial performed in a circuit consisting of three pneumatic cells G18. A comparison between the average results of the industrial trial including the carbonate otation stage and data of the raw industrial concentrate indicated that the MgO content in the concentrate dropped from 3.7%–3%. Concurrently, the carbonate content in the concentrate dropped from 11%–10.6%, the zinc grade in the concentrate increased from 41.4%–42% and the zinc recovery increased from 86.6%–89.8%. The concentrate was processed in the hydrometallurgical plant with no frothing problems.Item Kaolinite and hematite flotation separation using etheramine and ammonium quaternary salts.(2013) Rodrigues, Otávia Martins Silva; Peres, Antônio Eduardo Clark; Martins, Afonso Henriques; Pereira, Carlos AlbertoClay minerals are widespread in various types of mineral deposits. When present, they contribute to the high content of certain parameters such as silica, aluminium, and magnesium. This study aimed to find selectivity windows to separate hematite from a clay mineral (kaolinite) to allow reduction of the levels of silica and alumina in iron ore. The collectors used were: etheramine Flotigam EDA (EDA) and the ammonium quaternary salts: dodecyltrimethylammonium bromide (DTAB) and Tomamine Q-14-2 PG (AQ142). The depressant used was corn starch. The separation selectivity was achieved using DTAB in the pH range between 4 and 10. Using the collectors EDA and AQ142, the selectivity was obtained only in the presence of starch, at pH 10. Laboratory scale tests showed that as far as the particles size is concerned, better selectivity was achieved with finer particles. Circuit configurations including cleaner and scavenger stages, and pilot scale tests, will be required prior to a possible industrial implementation of the separation.Item Pilot scale direct flotation of a phosphate ore with silicate-carbonate gangue.(2012) Albuquerque, Rodrigo Oscar de; Peres, Antônio Eduardo Clark; Aquino, José Aury de; Praes, Plínio Eduardo; Pereira, Carlos AlbertoThe present pilot scale study addresses the direct flotation route for the concentration of a phosphate ore bearing a silicate-carbonate gangue. The target was to selectively separate apatite from a phosphate ore bearing silicate/carbonate gangue using flotation columns. Based on the results of a previous laboratory scale investigation, a reagents scheme was selected and tested, using, under alkaline conditions, corn starch and a natural collector extracted from the distillation of coconut oil. An open rougher-cleaner circuit yielded a final concentrate reaching 30.5% P2O5 grade, at 80.8% recovery level.Item Flotation concentration of a xenotime pre-concentrate.(1997) Pereira, Carlos Alberto; Peres, Antônio Eduardo ClarkThe worm market for rare-earths elements is increasing due to the development of new products and applications, resulting in the need for technology to treat deposits having highly complex mineralogy, such as that of Pitinga, AM, Brazil, with estimated reserves of 146,960 t of rare-earths oxides (REO), including Y203. Mineralogically the mine of Pitinga is very rich. The initial and major target of the company Paranapanema was the production of tin concentrates from placer deposits and later from primary ore. However, geological studies identified several other minerals of potential economical importance, such as: columbite-tantalite, zircon, cryolite and xenotime, the objective of the present investigation. The response of a pre-concentrate sample of the non-conducting fraction from Pitinga " s electrostatic separator to laboratory scale physical concentration methods was very poor. Another possibility for the selective separation of xenotime and zircon (the major associated mineral) is flotation. Microflotation experiments were performed in a modified HaUimond tube with pure samples of xenotime and zircon, in the presence of hydroxamate as collector and five different reagents as depressants.Item Reagents in calamine zinc ores flotation.(2004) Pereira, Carlos Alberto; Peres, Antônio Eduardo ClarkOxidised zinc ores are traditionallyfloated with fattyamines as collector. The effectiveness of this reagent requires a pre-sulph-idisation stage with sodium sulphide in conjunction with soda ash. Especiallyin the case of calamine ores, a dispersing agent becomes necessary. The collector must be emulsified with a fuel oil and the frother. This flotation system is characterised by the use of verylarge amounts of reagents. The proportion of each reagent in the reagents system must be carefullyoptimised