A presença de elevada carga nitrogenada em corpos hídricos pode causar sérios impactos ambientais como a eutrofização e a toxicidade do meio. Um dos processos que possibilitam a remoção de nitrogênio de efluentes é a adsorção, na qual o uso de adsorventes alternativos tem sido aplicado para o aproveitamento de resíduos e redução dos custos no processo. Dentro deste contexto, o processo de extração e beneficiamento do carvão fóssil na Região Sul do Brasil produz um rejeito (RB) com características que possibilitam sua aplicação na síntese de zeólitas, as quais podem ser utilizadas como adsorventes. Assim, o objetivo da presente tese foi avaliar a remoção do íon amônio de soluções aquosas por adsorção utilizando-se zeólitas naturais e sintetizadas a partir do rejeito RB. Em um primeiro momento, experimentos de adsorção foram conduzidos utilizando-se zeólita Na-clinoptilolita para conhecimento dos parâmetros termodinâmicos e da capacidade de regeneração do material. Posteriormente, a síntese de zeólitas utilizando rejeito RB foi realizada variando-se a fonte de alumínio, o emprego da agitação do meio durante a síntese e temperatura de calcinação do rejeito. A caracterização dos materiais foi feita através das técnicas de Difração de Raios X (DRX), Microscopia Eletrônica de Varredura acoplada a Espectroscopia por Dispersão em Energia (MEV-EDS), Potencial Zeta (PZ), Fluorescência de Raios X (FRX), Porosimetria de Nitrogênio (BET), Espectroscopia no Infravermelho por Transformada de Fourier (FTIR) e Capacidade de Troca Catiônica (CTC). Por fim, experimentos de adsorção de amônio foram feitos para o material que apresentou o maior conteúdo de íons sódio em sua composição. Quanto aos estudos com a Na-clinoptilolita, o estudo termodinâmico demostrou que a constante de equilíbrio (K0) da adsorção da zeólita estimada por diferentes métodos pode apresentar variação de até 105 de um método para outro. O estudo em questão também revelou que o método de Gaines e Thomas é o mais adequado para a estimativa dos parâmetros termodinâmicos. Nos testes de regeneração da zeólita utilizando-se solução NaCl de 0,5 a 3,0 M foram obtidos valores acima de 76% de regeneração para toda faixa de concentração avaliada, sem o reuso da solução de NaCl. Os testes feitos com o reuso da solução salina na etapa da dessorção permitiram concluir que é possível tratar até 160 mL de efluente utilizando-se somente 20 mL de solução NaCl 1,0 M, mantendo-se uma capacidade de adsorção equivalente a 80% da capacidade original da zeólita. Através da aplicação de diferentes condições de síntese utilizando o rejeito RB, foram obtidos sete diferentes materiais. O material que apresentou maior conteúdo de Na+ em sua composição foi obtido utilizando-se: pré-tratamento do rejeito com calcinação a 800 °C, síntese sem agitação do meio reacional e sem adição de fonte de alumínio. As análises do material indicaram formação de zeólitas dos tipos SOD e LTA. Quanto à adsorção de íons amônio, o mesmo apresentou capacidade de adsorção (qe) equivalente a 6,8 mg·g-1 (a 25ºC), que corresponde a 34 % do valor obtido para a Na-clinoptilolita, indicando que a síntese ainda necessita de melhoramentos para tornar o material mais competitivo frente à zeólita natural comercializada. / The presence of high nitrogen loading in water bodies can cause serious environmental impacts, such as eutrophication and toxicity of the medium. One of the process that enables nitrogen removal from effluents is adsorption, in which the use of alternative adsorbents have been applied in order to reuse wastes from other production processes and for lowering costs. Within this context, the coal mining and beneficiation in southern Brazil generates a waste with features that allow its application in zeolite synthesis. Thus, the objective of this thesis was to evaluate the removal of ammonium from aqueous solutions by adsorption using a natural zeolite and a zeolite synthesized from coal beneficiation tailings. Firstly, adsorption experiments were conducted using the natural zeolite Na-clinoptilolite in order to understand the thermodynamics and regeneration of process. Then, zeolite synthesis experiments using coal beneficiation tailings (RB) were conducted by varying the source of aluminum, stirring during crystallization step, and the calcination temperature applied to RB. The characterization of materials was made through the techniques of X-Ray Diffraction (XRD), Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM-EDS), Zeta Potential (ZP), X-rays Fluorescence (XRF), Porosimetry of Nitrogen (BET), Infrared Spectroscopy Fourier Transform (FTIR) and Cation Exchange Capacity (CEC). Finally, a test of ammonium adsorption was made with the material that had the highest content of Na+ in its composition. Regarding the studies with Na-clinoptilolite, the thermodynamic study showed that the equilibrium constant (K0) to adsorption process estimated through different approaches can present variation of up to 105 from one method to another. This study also revealed that the Gaines and Thomas method was the most adequate to the estimative of thermodynamic parameters. In the Na-clinoptilolite regeneration tests using NaCl solution from 0.5 to 3.0 M were obtained values above 76% regeneration to whole concentration range evaluated, without the reuse of NaCl solution. Tests made with the reuse of saline solution in the desorption step showed that it is possible to treat up to 160 mL of effluent using only 20 mL of NaCl solution, maintaining an adsorption capacity of 80 % of zeolite original capacity. By applying different synthesis conditions using the by-product of coal processing, seven different materials were obtained. The material with the highest content of Na+ was obtained using: calcination at 800°C as a thermal pretreatment applied to the waste, no stirring of the reaction during crystallization step and no additional aluminum source. The analysis of this material indicated formation of zeolites SOD and LTA. This same material was tested for the adsorption of ammonium, resulting in adsorption capacity (qe) of 6.8 m2·g-1, under the same conditions as the test with Na-clinoptilolite (at 25 ºC), which corresponds to 34 % of Na-clinoptilolite capacity, indicating that the synthesis still need some improvement in order to make the synthetic material competitive faced with the natural one.

A presença de elevada carga nitrogenada em corpos hídricos pode causar sérios impactos ambientais como a eutrofização e a toxicidade do meio. Um dos processos que possibilitam a remoção de nitrogênio de efluentes é a adsorção, na qual o uso de adsorventes alternativos tem sido aplicado para o aproveitamento de resíduos e redução dos custos no processo. Dentro deste contexto, o processo de extração e beneficiamento do carvão fóssil na Região Sul do Brasil produz um rejeito (RB) com características que possibilitam sua aplicação na síntese de zeólitas, as quais podem ser utilizadas como adsorventes. Assim, o objetivo da presente tese foi avaliar a remoção do íon amônio de soluções aquosas por adsorção utilizando-se zeólitas naturais e sintetizadas a partir do rejeito RB. Em um primeiro momento, experimentos de adsorção foram conduzidos utilizando-se zeólita Na-clinoptilolita para conhecimento dos parâmetros termodinâmicos e da capacidade de regeneração do material. Posteriormente, a síntese de zeólitas utilizando rejeito RB foi realizada variando-se a fonte de alumínio, o emprego da agitação do meio durante a síntese e temperatura de calcinação do rejeito. A caracterização dos materiais foi feita através das técnicas de Difração de Raios X (DRX), Microscopia Eletrônica de Varredura acoplada a Espectroscopia por Dispersão em Energia (MEV-EDS), Potencial Zeta (PZ), Fluorescência de Raios X (FRX), Porosimetria de Nitrogênio (BET), Espectroscopia no Infravermelho por Transformada de Fourier (FTIR) e Capacidade de Troca Catiônica (CTC). Por fim, experimentos de adsorção de amônio foram feitos para o material que apresentou o maior conteúdo de íons sódio em sua composição. Quanto aos estudos com a Na-clinoptilolita, o estudo termodinâmico demostrou que a constante de equilíbrio (K0) da adsorção da zeólita estimada por diferentes métodos pode apresentar variação de até 105 de um método para outro. O estudo em questão também revelou que o método de Gaines e Thomas é o mais adequado para a estimativa dos parâmetros termodinâmicos. Nos testes de regeneração da zeólita utilizando-se solução NaCl de 0,5 a 3,0 M foram obtidos valores acima de 76% de regeneração para toda faixa de concentração avaliada, sem o reuso da solução de NaCl. Os testes feitos com o reuso da solução salina na etapa da dessorção permitiram concluir que é possível tratar até 160 mL de efluente utilizando-se somente 20 mL de solução NaCl 1,0 M, mantendo-se uma capacidade de adsorção equivalente a 80% da capacidade original da zeólita. Através da aplicação de diferentes condições de síntese utilizando o rejeito RB, foram obtidos sete diferentes materiais. O material que apresentou maior conteúdo de Na+ em sua composição foi obtido utilizando-se: pré-tratamento do rejeito com calcinação a 800 °C, síntese sem agitação do meio reacional e sem adição de fonte de alumínio. As análises do material indicaram formação de zeólitas dos tipos SOD e LTA. Quanto à adsorção de íons amônio, o mesmo apresentou capacidade de adsorção (qe) equivalente a 6,8 mg·g-1 (a 25ºC), que corresponde a 34 % do valor obtido para a Na-clinoptilolita, indicando que a síntese ainda necessita de melhoramentos para tornar o material mais competitivo frente à zeólita natural comercializada. / The presence of high nitrogen loading in water bodies can cause serious environmental impacts, such as eutrophication and toxicity of the medium. One of the process that enables nitrogen removal from effluents is adsorption, in which the use of alternative adsorbents have been applied in order to reuse wastes from other production processes and for lowering costs. Within this context, the coal mining and beneficiation in southern Brazil generates a waste with features that allow its application in zeolite synthesis. Thus, the objective of this thesis was to evaluate the removal of ammonium from aqueous solutions by adsorption using a natural zeolite and a zeolite synthesized from coal beneficiation tailings. Firstly, adsorption experiments were conducted using the natural zeolite Na-clinoptilolite in order to understand the thermodynamics and regeneration of process. Then, zeolite synthesis experiments using coal beneficiation tailings (RB) were conducted by varying the source of aluminum, stirring during crystallization step, and the calcination temperature applied to RB. The characterization of materials was made through the techniques of X-Ray Diffraction (XRD), Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM-EDS), Zeta Potential (ZP), X-rays Fluorescence (XRF), Porosimetry of Nitrogen (BET), Infrared Spectroscopy Fourier Transform (FTIR) and Cation Exchange Capacity (CEC). Finally, a test of ammonium adsorption was made with the material that had the highest content of Na+ in its composition. Regarding the studies with Na-clinoptilolite, the thermodynamic study showed that the equilibrium constant (K0) to adsorption process estimated through different approaches can present variation of up to 105 from one method to another. This study also revealed that the Gaines and Thomas method was the most adequate to the estimative of thermodynamic parameters. In the Na-clinoptilolite regeneration tests using NaCl solution from 0.5 to 3.0 M were obtained values above 76% regeneration to whole concentration range evaluated, without the reuse of NaCl solution. Tests made with the reuse of saline solution in the desorption step showed that it is possible to treat up to 160 mL of effluent using only 20 mL of NaCl solution, maintaining an adsorption capacity of 80 % of zeolite original capacity. By applying different synthesis conditions using the by-product of coal processing, seven different materials were obtained. The material with the highest content of Na+ was obtained using: calcination at 800°C as a thermal pretreatment applied to the waste, no stirring of the reaction during crystallization step and no additional aluminum source. The analysis of this material indicated formation of zeolites SOD and LTA. This same material was tested for the adsorption of ammonium, resulting in adsorption capacity (qe) of 6.8 m2·g-1, under the same conditions as the test with Na-clinoptilolite (at 25 ºC), which corresponds to 34 % of Na-clinoptilolite capacity, indicating that the synthesis still need some improvement in order to make the synthetic material competitive faced with the natural one.

Considerando a crescente demanda por energia e tendo em vista uma matriz diversificada, faz-se necessário o estudo das jazidas carboníferas não exploradas, como é o caso da Jazida de Morungava, em cujas últimas pesquisas datam da década de 1980. A jazida situa-se no nordeste do estado do Rio Grande do Sul, com uma área de abrangência de cerca de 250km2. Realizou-se um poço exploratório para estudar o carvão e avaliar a economicidade da jazida, por meio de caracterização petrográfica, química e tecnológica das camadas obtidas no poço CBM 001-MO-RS, que atingiu a profundidade de 387,70m, uma espessura cumulativa de carvão de 9,22m. Identificou-se 6 camadas de carvão, das quais obteve-se 27 amostras. Para caracterizar as amostras, realizou-se: descrições de litotipos do carvão, refletância da vitrinita, contagem de macerais, análises imediatas, poder calorífico superior, enxofre total, difração de raios-X e teste de beneficiamento. O litotipo carvão fosco é predominante nas amostras, com um rank variando de carvão betuminoso alto volátil A à antracito.As amostras, estão afetadas progressivamente por intrusão vulcânica sotoposta. O grupo maceral vitrinita predomina nos carvões na porção inferior, enquanto inertinita predomina na superior. Matéria mineral apresenta uma tendência de aumento da base para o topo. Os carvões apresentaram altos teores de cinza (>50%m.b.s.), matéria volátil (6,04-30,69%m.b.s), enxofre (0,20-2,88%m) e poder calorífico superior (777-4.732Kcal/Kg). Ocorre um predomínio mineralógico de quartzo, caulinita, e illita. A maioria das camadas são classificadas como rocha carbonosa (>50% cinza/b.s.). Em ensaios de beneficiamento foi observado um baixo rendimento (<7%vol.), na obtenção de produtos nobres. / Considering the growing demand for energy and with a view to a diverse energy matrix, it is necessary to study the coal deposits not or little exploited, such as the Morungava coalfield, where the latest research is dating back to the 1980s. The Coalfield is located in the northeast of Rio Grande do Sul State, Brazil. The present study characterizes coal seams obtained from borehole CBM 001-MO-RS, which reached a depth of 387,70 m. 6 coal seams were identified, with a cumulative coal thickness of 9,22 m, from which 27 coal samples were taken for analyses. The following methods were applied: lithotype description, vitrinite reflectance measurement, maceral analyses, proximate analysis, calorific value analysis, sulphur determination, x-ray diffraction and beneficiation tests. The lithotype dull coal is prevalent in the samples. Coal rank ranges from high volatile bituminous A coal to anthracite, with samples progressively affected by an overlying volcanic intrusion. The vitrinite maceral group dominates the coals in the lower portion, whereas inertinite prevails at the top. The coals show high ash content (> 40 wt.% d.f.). Volatile matter ranges from 6.04 to 30.69 wt.% d.f,,sulfur ranges from 0.20 to 2.88 wt.%, and gross calorific values range from 777 - 4732 Kcal/kg). There is a predominance of quartz, kaolinite and illite in the mineral fraction. Beneficiation tests indicate a very low yield in better quality, low ash coal. Most of the coal seams are classified as carbonaceous rock (> 50% Ash/d.f.).

Considerando a crescente demanda por energia e tendo em vista uma matriz diversificada, faz-se necessário o estudo das jazidas carboníferas não exploradas, como é o caso da Jazida de Morungava, em cujas últimas pesquisas datam da década de 1980. A jazida situa-se no nordeste do estado do Rio Grande do Sul, com uma área de abrangência de cerca de 250km2. Realizou-se um poço exploratório para estudar o carvão e avaliar a economicidade da jazida, por meio de caracterização petrográfica, química e tecnológica das camadas obtidas no poço CBM 001-MO-RS, que atingiu a profundidade de 387,70m, uma espessura cumulativa de carvão de 9,22m. Identificou-se 6 camadas de carvão, das quais obteve-se 27 amostras. Para caracterizar as amostras, realizou-se: descrições de litotipos do carvão, refletância da vitrinita, contagem de macerais, análises imediatas, poder calorífico superior, enxofre total, difração de raios-X e teste de beneficiamento. O litotipo carvão fosco é predominante nas amostras, com um rank variando de carvão betuminoso alto volátil A à antracito.As amostras, estão afetadas progressivamente por intrusão vulcânica sotoposta. O grupo maceral vitrinita predomina nos carvões na porção inferior, enquanto inertinita predomina na superior. Matéria mineral apresenta uma tendência de aumento da base para o topo. Os carvões apresentaram altos teores de cinza (>50%m.b.s.), matéria volátil (6,04-30,69%m.b.s), enxofre (0,20-2,88%m) e poder calorífico superior (777-4.732Kcal/Kg). Ocorre um predomínio mineralógico de quartzo, caulinita, e illita. A maioria das camadas são classificadas como rocha carbonosa (>50% cinza/b.s.). Em ensaios de beneficiamento foi observado um baixo rendimento (<7%vol.), na obtenção de produtos nobres. / Considering the growing demand for energy and with a view to a diverse energy matrix, it is necessary to study the coal deposits not or little exploited, such as the Morungava coalfield, where the latest research is dating back to the 1980s. The Coalfield is located in the northeast of Rio Grande do Sul State, Brazil. The present study characterizes coal seams obtained from borehole CBM 001-MO-RS, which reached a depth of 387,70 m. 6 coal seams were identified, with a cumulative coal thickness of 9,22 m, from which 27 coal samples were taken for analyses. The following methods were applied: lithotype description, vitrinite reflectance measurement, maceral analyses, proximate analysis, calorific value analysis, sulphur determination, x-ray diffraction and beneficiation tests. The lithotype dull coal is prevalent in the samples. Coal rank ranges from high volatile bituminous A coal to anthracite, with samples progressively affected by an overlying volcanic intrusion. The vitrinite maceral group dominates the coals in the lower portion, whereas inertinite prevails at the top. The coals show high ash content (> 40 wt.% d.f.). Volatile matter ranges from 6.04 to 30.69 wt.% d.f,,sulfur ranges from 0.20 to 2.88 wt.%, and gross calorific values range from 777 - 4732 Kcal/kg). There is a predominance of quartz, kaolinite and illite in the mineral fraction. Beneficiation tests indicate a very low yield in better quality, low ash coal. Most of the coal seams are classified as carbonaceous rock (> 50% Ash/d.f.).

A strategy for beneficiation of wastewater streams from fissure and process water developed for a gold mine operation in the west of Johannesburg was tested for viability in a pilot study. The investigation was aimed at evaluating the compliance of the finally discharged effluent streams with the current Water Use Licence (WUL). The core of the water recovery process consisted of softening to remove divalent cationic species, followed by ion exchange processes employing Strong Acid Cationic (SAC) resins and Weak Acid Cationic (WAC) resins. An operational design limitation was that the crystalactor used in the softening stage had a minimum capacity of 20 000 L/h, whereas the rest of the system could be operated at flow rates of as low as 2 000 L/h. For this reason, the softening step was done in semi-batch mode. Calcium hardness was decreased from 70 mg/L to values lower than 40 mg/L (as Ca2+). During the ion exchange (water recovery) process, columns using SAC resin produced better quality water than the WAC resins. The SAC columns produced water compatible with South African Water Quality Standards. Additionally, the use of SAC proved to be a more financially favourable option, since the regenerant stream contained high concentrations of calcium nitrate, magnesium nitrate and sodium nitrate fertilizer. The latter could be sold as a liquid fertilizer to farmers. In addition to the above findings, the pilot system reduced the concentration of toxic and radiotoxic metals such as uranium. The final concentration of the uranium in the effluent (0.01 mg/L) was below the regulation limit 0.07 mg/L. The selective removal of uranium is crucial in order to produce high-quality fertilizer from the ion exchange regeneration streams. Copyright / Dissertation (MEng)--University of Pretoria, 2013. / Chemical Engineering / unrestricted

Commodity projection studies anticipate an exponential increase in copper demand and decreasein mill grade of deposits currently exploited globally. Most of this demand is driven by theindispensable use of copper in electrification and currently, the growing demand in the contextof the green transition. To meet this challenge while supplying society with copper, producerssuch as Boliden AB have plans for exploration and expansion projects to increase their reservesand in turn increase production through efficient measures. As grinding is a bottleneck to mineralprocessing and the most energy intensive, more efficient comminution systems are beingconsidered for environmental sustainability. These are required to have lower energyconsumption while achieving the required liberation or better for subsequent processing byflotation. Consequently, the literature review shows there is a research query on whether more can beexpected from comminution to optimise for downstream processing. With most publishedresearch being on particles with a P80 less than 100 μm, there exists a gap in investigating theeffect of grinding on flotation for coarser size fractions which this degree project focuses on.Importantly, it includes evaluating chalcopyrite liberation and flotation performance when usinga Novel Comminution Device. Three grinding mills were considered, a vertical roller mill (VRM),a Novel Comminution Device (NCD), with a rod mill as the reference mill. The scope of this studywas an analysis of the mill products’ particle size distribution, chalcopyrite liberation andinvestigation of the flotation performance of the products from the three mills. This was done ona Cu-Au-Ag ore from the Boliden Aitik mine in northern Sweden. Particle size distribution (PSD) analysis revealed that at comparable P80 values, the VRMproduced particles had broader PSD curves than the rod mill, while the NCD provided a steeperproduct size distribution than its reference rod mill products. The chalcopyrite liberation analysisusing QEMSCAN automated mineralogy showed that for samples split into three size fractions, -45 μm, +45/-90 μm and +90 μm, the VRM and rod mill products had their highest proportion offree to liberated particles within the intermediate size fraction while for the NCD sample this waswithin the fine fraction. Overall, the NCD product had the highest free to liberated particles acrossall fractions. From shape analysis based on scanning electron microscopy (SEM) images, it wasobserved that the NCD produced particles with the higher elongation than the VRM and rod mill. The flotation performance was assessed with respect to the mass pull, kinetics, grade andrecovery in the concentrate and separation efficiency. The rougher batch flotation tests indicatedthat flotation of the VRM ground samples had higher mass pull, Cu recovery, faster kinetics andlower Cu grade than the samples from the reference rod mill. This was also a similar outcome forthe NCD with the exception of higher mass pull at an increased collector dosage in the rod millcase. For all the mills, the general trend showed that an increase in P80 was associated withreduced mass pull. Overall, at similar flotation conditions, despite having one of the coarsest P80s,the NCD product showed the fastest Cu recovery kinetics, highest total recovery and selectivityindex. The rod mill reference test samples gave the highest grade but the lowest recovery. The findings illustrate that there is a significant difference in PSD broadness between productsfrom different mills at comparable P80. The differences in flotation performance between thethree mill products were mainly attributed to differences in liberation, potential differences insurface activation between wet and dry grinding methods and to some extent, steepness of thePSD curve. Based on the high recovery yet low grade of the NCD ground product, this is best suitedfor the rougher flotation stage. Future studies should therefore include cleaner stage flotation andoptimisation tests for the NCD with respect to reagent dosages and hydrodynamic conditions.

Tungsten (W) is listed among the European Union (EU) critical raw materials (CRMs) for its supply risk and economic importance. Primarily, tungsten is produced from scheelite and wolframite mineral ores with 0.08-1.5% tungsten trioxide (WO3) grade. However, as primary deposits for these resources are becoming less or lower in grade, alternative sources need to be explored. These alternative tungsten sources include scrap from end-of-life products, mine waste and rejects from the ore beneficiation processes (tailings). The latter alternative source is the focus within this thesis. Historical tailings repositories often pose environmental risks but may also become secondary sources of CRMs. This is because of relatively high minerals and metals content due to less efficient extraction methods and/or relatively low metal prices at the time of active mining. Therefore, reprocessing of such tailings is not only a supply risk-reducing measure but also an approach to remediation that contributes to the mining industry’s aim of moving towards a circular economy. The aim of this thesis has been to develop efficient methods for separating valuable minerals from the tailings in order to leave behind a stable and environmentally safe residue. Geometallurgical studies were conducted by collecting drill core samples from the Smaltjärnen tailings repository in Yxsjöberg, Sweden, for evaluating the potential of this repository for further processing. The tailings were originally produced from the ore that was mined by Yxsjö Mines while it was in operation from 1935 to 1963, with average ore grades of 0.3-0.4 wt.% WO3, 0.2 wt.% Cu and 5-6 wt.% fluorspar. The exploited minerals were scheelite for W, chalcopyrite for Cu and fluorspar. The tailings repository is estimated to have about 2.2 million tons of tailings covering an area of 26 hectares, with elemental concentrations of 1-2 wt.% S, 0.02-0.2 wt.% Cu, 0.02-0.3 wt.% W, 0.02-0.04 wt.% Sn and 0.02-0.03 wt.% Be. Sampling and characterization of the historical tailings were conducted based on geometallurgical units (i.e. a distinction between different layers and locations in the repository), followed by metallurgical test work. The tailings were characterized with regard to color and granulometry, particle size distribution, chemical composition, scheelite mineral occurrence, texture and mineral liberation, as well as mineralogical composition. Based on a comprehensive literature survey, tailings characteristics, and assessment of the earlier processes from which the Yxsjöberg tailings were produced, feasible separation methods were pre-selected involving dry low-intensity magnetic separation (LIMS) and high intensity magnetic separation (HIMS), enhanced gravity separation (EGS) using a Knelson concentrator, and batch froth flotation. The average WO3 and Cu concentration in these tailings based on the sampled locations was 0.15 % and 0.11 % respectively. Applying them to the estimated 2.2 million tons of tailings in this repository gives approximately 3300 tons of WO3 and 2512 tons of Cu. From the metallurgical test work, several feasible processing routes have been identified that need to be further assessed based on the economic and environmental criteria. / REMinE (Improve Resource Efficiency and Minimize Environmental Footprint)

Este estudo apresenta ao Departamento de Engenharia de Minas e Petróleo (PMI) da Escola Politécnica da USP, e também a toda a sociedade, a importância que os oceanos têm com relação às suas riquezas minerais. Pretende ainda mostrar a grande responsabilidade que um empreendimento mineiro no fundo do mar precisa ter, com relação aos impactos ambientais, sendo possível minerar em regiões profundas no oceano promovendo a sustentabilidade. A ideia da mineração oceânica/submarina está ainda sendo amadurecida, este é o momento adequado para se propor metodologias de trabalho submarino sustentáveis; mitigar seus impactos. Este trabalho abrange o tema de maneira ampla, abordando o aspecto histórico, legal, ambiental, bem como questões técnicas de engenharia de minas, como sondagem submarina, caracterização tecnológica, lavra submarina, beneficiamento de minério oceânico e descarte de rejeitos. O trabalho apresenta os passos e resultados de um caso real de exploração oceânica. Trata-se de um estudo para viabilizar economicamente a extração e o beneficiamento de areia marinha, para fins industriais, proveniente da Baía de Guanabara (RJ). O trabalho apresenta desde o planejamento da amostragem no fundo do mar, execução destes trabalhos, caracterização tecnológica, simulação de processo e estudos específicos do uso industrial da areia após beneficiamento. Apresenta ainda uma proposta de rota de processo para a areia marinha e questões ligadas à lavra e ao descarte de rejeitos. / This study aims to show the importance of the oceans and its mineral wealth. It intends also to show the big responsibility that an undersea enterprise must bear concerning the environmental impact. It shows the availability to minein a sustainable way in the bottom of the sea. The undersea mining is still raising, now is the auspicious time to suggest sustainably submarine work methodologies; to mitigate its impact. This study covers the historic, legal and environmental aspects, as well as technical issues of mining engineering such as undersea survey, process mineralogy, undersea mining, mineral beneficiation for marine ores and tailings disposal. This study presents the steps and results of a real subsea exploration case. The studied ore is a marine sand from Baía de Guanabara (Rio de Janeiro), aiming to supply industrial market. This is a feasibility and technical study to show how to exploit and process this kind of ore. The study shows the undersea survey planning and its execution, the process mineralogy planning and its results, process simulation and some specific studies to industrial uses for this sand, after its beneficiation. Besides these subjects, the study proposes an industrial process route for process and tailings disposal.

Este estudo apresenta ao Departamento de Engenharia de Minas e Petróleo (PMI) da Escola Politécnica da USP, e também a toda a sociedade, a importância que os oceanos têm com relação às suas riquezas minerais. Pretende ainda mostrar a grande responsabilidade que um empreendimento mineiro no fundo do mar precisa ter, com relação aos impactos ambientais, sendo possível minerar em regiões profundas no oceano promovendo a sustentabilidade. A ideia da mineração oceânica/submarina está ainda sendo amadurecida, este é o momento adequado para se propor metodologias de trabalho submarino sustentáveis; mitigar seus impactos. Este trabalho abrange o tema de maneira ampla, abordando o aspecto histórico, legal, ambiental, bem como questões técnicas de engenharia de minas, como sondagem submarina, caracterização tecnológica, lavra submarina, beneficiamento de minério oceânico e descarte de rejeitos. O trabalho apresenta os passos e resultados de um caso real de exploração oceânica. Trata-se de um estudo para viabilizar economicamente a extração e o beneficiamento de areia marinha, para fins industriais, proveniente da Baía de Guanabara (RJ). O trabalho apresenta desde o planejamento da amostragem no fundo do mar, execução destes trabalhos, caracterização tecnológica, simulação de processo e estudos específicos do uso industrial da areia após beneficiamento. Apresenta ainda uma proposta de rota de processo para a areia marinha e questões ligadas à lavra e ao descarte de rejeitos. / This study aims to show the importance of the oceans and its mineral wealth. It intends also to show the big responsibility that an undersea enterprise must bear concerning the environmental impact. It shows the availability to minein a sustainable way in the bottom of the sea. The undersea mining is still raising, now is the auspicious time to suggest sustainably submarine work methodologies; to mitigate its impact. This study covers the historic, legal and environmental aspects, as well as technical issues of mining engineering such as undersea survey, process mineralogy, undersea mining, mineral beneficiation for marine ores and tailings disposal. This study presents the steps and results of a real subsea exploration case. The studied ore is a marine sand from Baía de Guanabara (Rio de Janeiro), aiming to supply industrial market. This is a feasibility and technical study to show how to exploit and process this kind of ore. The study shows the undersea survey planning and its execution, the process mineralogy planning and its results, process simulation and some specific studies to industrial uses for this sand, after its beneficiation. Besides these subjects, the study proposes an industrial process route for process and tailings disposal.

Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)