Physical, chemical and mineralogical characterization of a Brucutu iron ore sample.

A caracteriza??o de um min?rio permite a previsibilidade do seu comportamento frente aos processos de concentra??o. Apenas dados granuloqu?micos nem sempre s?o suficientes, sendo o reconhecimento das esp?cies minerais, suas propor??es, forma de gr?os e liberabilidade tamb?m fundamentais. Neste trabalho ? apresentada a caracteriza??o f?sica, qu?mica e mineral?gica de um min?rio de ferro da mina de Brucutu/Quadril?tero Ferr?fero-MG. Foram realizadas an?lises granulom?tricas por peneiramento e granul?metro a laser, qu?micas por fluoresc?ncia de raios X e mineral?gica por microscopia ?ptica e difra??o de raios X. Baseado nos resultados obtidos, o min?rio foi classificado como fri?vel, com teor global de Fe igual a 42,9% e SiO2 de 36,1%. Os minerais de ferro identificados foram hematita e goethita e, o principal mineral de ganga o quartzo. Na fra??o +1,0 mm o quartzo ocorre majoritariamente em part?culas mistas com os gr?os de hematita e goethita. Abaixo desta granulometria, o mesmo ocorre como part?culas livres. Acima de 0,15 mm a hematita ? predominantemente porosa, e abaixo de 0,15 mm granular. A goethita encontra-se associada ? hematita granular em todas as fra??es granulom?tricas.The characterization of an ore allows the predictability of its behavior in relation to the concentration methods. Only size and chemical analyses are not always sufficient, and the recognition of mineral species, their proportions, grain form, and liberability are also fundamental. In this work the physical, chemical and mineralogical characteristics of an iron ore from Brucutu mine in Quadril?tero Ferr?fero is presented. Particle size analyses were carried out by sieve and laser granulometer, chemistry by X-ray fluorescence and mineralogical by optical microscopy and X-ray diffraction. Based on the results obtained, the ore was classified as friable, with an overall Fe content of 42.9% and SiO2 of 36.1%. The iron minerals identified were hematite and goethite, and the main gangue mineral was quartz. In the fraction +1.0 mm the quartz occurs mainly in mixed particles with the hematite and goethite grains. Below this size, the same occurs as free particles. Above 0.15 mm the hematite is predominantly porous, and below 0.15 mm granular. Goethite is associated with granular hematite in all size distribution

Principal components analysis applied to flotation of iron ore.

A flota??o ? um processo de concentra??o, usualmente, empregado no beneficiamento do min?rio de ferro. O presente trabalho teve como objetivo avaliar a influ?ncia de vari?veis no processo de flota??o em bancada utilizando a t?cnica de an?lise de componentes principais. Para isso, realizou-se uma an?lise estat?stica com o aux?lio do software R, onde foram estudados os teores de s?lica e ferro na alimenta??o, no concentrado e no rejeito, teores dos contaminantes na alimenta??o (lama, ?xido de c?lcio e ?xido de magn?sio), perda por calcina??o e dosagem de amina. Por meio da an?lise foi poss?vel concluir que as duas primeiras componentes explicaram juntas aproximadamente 45% da variabilidade total da matriz de dados. A primeira componente explicou em torno de 25% da vari?ncia, sendo relacionada com a perda de seletividade do processo de flota??o. J? a segunda componente explicou cerca de 20% da vari?ncia e descreveu a inefici?ncia do processo. Atrav?s dos estudos realizados, foi poss?vel observar que a t?cnica de an?lise de componentes principais pode ser utilizada para melhor entendimento das vari?veis dos processos de flota??o em bancada.Flotation is a process of concentration, usually, employed in iron ore processing. The present work aimed to evaluate the influence of variables in the flotation process in the bench-scale using the principal components analysis technique. For this purpose, a statistical analysis by using the software R was carried out, studying the silica and the iron contents in the feed, in the concentrate and in the tailings as well as the contaminants (mud, calcium oxide and magnesium oxide) in the feed and also the loss on ignition and amine dosing. The analysis has allowed to conclude that the first two components together account for approximately 45% of the total variability of the data matrix. The first component explained about 25% of the variance, related to the loss of selectivity of the flotation process. The second component explained about 20% of the variance and described the inefficiency of the process. The conducted studies have shown that the principal components analysis technique can be used to a better understanding of the variables of the bench-scale flotation processes

Incorpora??o de res?duos da fabrica??o de ferro-ligas de mangan?s e de finos de esteatito na produ??o de cer?mica vermelha.

Programa de P?s-Gradua??o em Engenharia Mineral. Departamento de Engenharia de Minas, Escola de Minas, Universidade Federal de Ouro Preto.A produ??o de rejeitos provenientes do setor m?nero-metal?rgico ? um dos fatores de contamina??o ambiental e tem despertado a aten??o no sentido de seu reaproveitamento. Durante o processo de fabrica??o de ferro-ligas de mangan?s ? gerada grande quantidade de rejeitos inerentes ao processo, dentre estes, o lodo dos tanques de decanta??o que recebem os efluentes l?quidos. O processo de fabrica??o das pe?as artesanais de pedra-sab?o tamb?m gera uma grande quantidade de res?duos, como os finos, dispostos muitas vezes pr?ximo ?s oficinas sem nenhuma forma de controle. Este trabalho teve como objetivo caracterizar o lodo proveniente de tanques de decanta??o de uma usina de fabrica??o de ferro-ligas de mangan?s da regi?o de Ouro Preto - MG. Posteriormente, foram confeccionados e caracterizados corpos de prova cer?micos com substitui??o de parte da massa argilosa por lodo e avaliada a efici?ncia da incorpora??o na fabrica??o de cer?mica. Com a utiliza??o de t?cnicas de planejamento estat?stico de experimentos foram avaliadas se as vari?veis press?o de compacta??o (14 e 28MPa), substitui??o do solo por res?duo (5 e 10%) e temperatura de queima (850 e 1000oC) t?m influ?ncia nas propriedades de retra??o linear de secagem e queima, absor??o de ?gua, massa espec?fica aparente e resist?ncia ? compress?o dos corpos queimados. Como trabalhos anteriores com substitui??o somente por finos de pedra-sab?o demonstraram resultados satisfat?rios, realizou-se substitui??o do solo por lodo e esteatito em um mesmo corpo de prova, na melhor condi??o analisada, a fim de se obter uma resposta otimizada do processo. Baseado nas investiga??es foi poss?vel concluir que o lodo ? composto por quartzo, calcita, muscovita e caulinita, com presen?a de liga de mangan?s e esc?ria. Analisando os resultados com substitui??o do solo por lodo do tanque de decanta??o, observou-se que a melhor condi??o para fabrica??o de cer?mica seria com temperatura de queima de 1000oC, press?o de compacta??o de 28MPa e substitui??o de 5%. Em rela??o aos corpos de prova com substitui??o do solo por lodo e esteatito, percebeu-se que com a adi??o de esteatito ocorreu uma melhora nas propriedades de retra??o linear de secagem e queima e absor??o de ?gua. Os melhores resultados foram obtidos para os corpos de prova com substitui??o de solo por lodo e esteatito, com forma??o das novas fases cristalinas, espin?lio e enstatita, sendo que os par?metros analisados se apresentaram dentro do estabelecido para aplica??es tecnol?gicas. O res?duo do corpo de prova foi classificado como n?o perigoso e n?o inerte.The production of waste from the mining-metallurgical sector is one of the factors of environmental contamination and has aroused the attention of its reuse. In the production units of ferromanganese alloys are generated a large amount of waste, for example, the sludge formed in the settling tanks that receive the liquids effluents. The process of manufacturing the soapstone handmade pieces also generates a great amount of waste generated during the process, such as soapstone powder, that are normally discarded in inadequate places, without any form of control. The aim of this work was to characterize the sludge from settling tanks of a ferromanganese alloy manufacturing plant in Ouro Preto region. Subsequently, ceramic bricks were prepared and characterized with replacement of part of the clay mass by sludge and the efficiency of the incorporation in the ceramic production was evaluated. It was designed a factorial experimental design for the ceramics bricks prepared with composition of clay plus sludge to investigate whether the variables: replacement of soil for sludge (5 and 10%), compaction pressure (14 and 28MPa) and firing temperature (850 and 1000oC) had an influence on the responses (linear shrinkage, water absorption, firing specific weight and compressive strength). As previous work with replacement by soapstone powder showed satisfactory results, tests were carried out with replacement of part of the clay mass by sludge and steatite in the same brick, in the best condition analyzed, in order to obtain an optimized response of the process. Based on the investigations, it was possible to conclude that the sludge is composed of quartz, calcite, muscovite and kaolinite, with the presence of manganese alloy and slag. It can be seen that the best condition for ceramic production would be with a firing temperature of 1000oC, compaction pressure of 28MPa and 5% of replacement. In relation to the bricks with soil replacement by sludge and steatite, it was observed that with the addition of steatite an improvement in the linear shrinkage of drying and firing and water absorption properties. The best results were obtained for the bricks with soil replaced by sludge and steatite, with formation of the new crystalline phases, spinel and enstatite. The parameters analyzed were within the established for technological applications. The residue was classified as non-hazardous and not inert

Evaluation of Compressive Strength of Manganese Oxidized Ore Briquettes: Effects of Compaction Pressure, Curing Time, and Percentage of Binder

Agglomeration is a common process to safely recycle wastes from the mining and metallurgical sectors. In this process, the mineralogical and chemical characteristics of manganese ores exert a significant influence on the reduction reactions within the electric furnace. Therefore, a systematic work has been done to evaluate the compressive strength of briquettes composed of manganese oxidized ore fines, ferromanganese dust, charcoal fines, and three different binders, bentonite, pregelatinized starch, and slaked lime + molasses. A response surface methodology was used to evaluate the effects of compaction pressure, curing time, and % binder, whose response was measured in terms of compressive strength. The results were assessed by Analysis of Variance and a regression model was generated. The study showed that briquettes with bentonite demonstrated an optimized compressive strength of 2.54 MPa with a compaction pressure of 52.5 MPa, 11 days of curing time, and 11.5% bentonite content. Briquettes with slaked lime + molasses achieved a compressive strength of 3.70 MPa with a compaction pressure of 62.12 MPa, a curing time of 24 days, and an addition of 16.2% slaked lime + molasses. For briquettes produced with pre-gelatinized starch, the design of the proposed variables resulted in a lack of fit to the model. Optimization studies revealed that briquettes made with bentonite and slaked lime + molasses are viable alternatives to replace oxidized lump ore in electric furnaces.</p

Incorporation of waste from ferromanganese alloy manufacture and soapstone powder in red ceramic production.

The production of waste from the mining-metallurgical sector is one of the factors of environmental contamination and exploring ways to reuse this waste have attracted considerable research attention. This study proposes the use of residues generated from the manufacturing processes of ferromanganese alloy and soapstone powder for the production of red ceramic. Ceramic bricks were prepared with clay and sludge to investigate the effect of a number of variables, including the replacement of clay with sludge (5% and 10%), compaction pressure (14 and 28 MPa), and firing temperature (850 ?C and 1000 ?C) on the linear shrinkage, water absorption, firing specific weight, and compressive strength of the bricks. Also tests were carried out with replacement of part of the clay mass by sludge and steatite in the same brick. The best condition for ceramic production was found to be a firing temperature of 1000 ?C and compaction pressure of 28 MPa with 5% of clay replaced by sludge. The best results were obtained for bricks with clay replaced by both sludge and steatite, which prompted the formation of the new crystalline phases, spinel and enstatite. After analysis, the brick residue was classified as Non Hazardous and Not Inert. The analyzed parameters were within the established limits for technological applications