Made available in DSpace on 2014-06-11T19:27:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-25Bitstream added on 2014-06-13T20:57:03Z : No. of bitstreams: 1 sales_mfg_me_rcla.pdf: 1966151 bytes, checksum: 5e10751ba25c6ea670c81c5f519f0ad7 (MD5) / A atividade mineradora é de grande relevância para a economia brasileira, visto que fornece insumos básicos para o processo de expansão industrial e urbana. Entretanto, a mineração é responsável por uma série de alterações no ambiente natural, principalmente nas proximidades do local onde a atividade é instalada. Levando em consideração que a área de estudo, localizada no Bairro Santo Antônio (Zona Sul de Teresina-PI), foi alvo de uma intensa mineração de materiais utilizados na construção civil, o que resultou na degradação ambiental da área, o presente trabalho visou diagnosticar os conflitos socioeconômicos e ambientais associados ao uso e ocupação da área de degradação urbana decorrente da atividade extrativista mineral. Este estudo partiu da pesquisa bibliográfica e documental, seguida da aplicação de questionários, do registro fotográfico da área, além do mapeamento com a utilização da tecnologia de GPS, mapas e imagens de satélite. Dentre os resultados obtidos, foram observadas grandes alterações físicas ocorridas no ambiente, ao se comparar a época relativa ao início da exploração mineral e os dias de hoje. Observou-se ainda um processo desordenado e acelerado de ocupação da área de estudo, com um acréscimo de 94,84% na população local com relação aos anos de 2000 a 2007. A partir desta pesquisa, concluiu-se que a população residente nessa área vive à margem das ações do poder público, pois não possui acesso à infraestrutura básica adequada, o que pode ser reflexo da condição degradada do local onde reside / Mining is of great importance for the Brazilian economy, since it provides basic inputs to the process of industrial expansion and urban, but mining is responsible for a series of changes in the natural environment, especially in the area where the activity is installed. Considering that the study area, located in the Barrio Santo Antonio (South Zone Teresina-PI) was the target of intense mining of materials used in construction, which resulted in environmental degradation of the area, this study aimed to diagnose socioeconomic and environmental conflicts associated with use and occupancy of the area of urban decay caused by mineral extraction activities. In this sense, the study came from research literature and documents, the use of questionnaires, the photographic record of the area, in addition to mapping with the use of GPS technology, maps and satellite images. Among the results, we observed significant changes occurred in the physical environment, when comparing the start of the season on mineral exploration to the present day. We also observed a rapid and disorderly process of occupation of the study area, with an increase of 94.84% compared to the years 2000 to 2007. From this research, we concluded that the resident population in this area live on the margins of the actions of government, it does not have adequate access to basic infrastructure which may reflect the degraded condition of the place where he lives

Em junho de 2013, o Governo Federal enviou ao Congresso Nacional uma proposta para o novo marco regulatória da mineração. No entanto, críticos dessa proposta alegam que, caso o aumento dos royalties da mineração pretendido pelo Governo não ocorra no bojo de uma reforma tributária mais ampla, a nova carga tributária pode inflar demasiadamente o custo de extração de alguns minérios no Brasil, prejudicando sua inserção no mercado internacional e, consequentemente, desestimulando investimentos produtivos no país. Neste sentido, o objetivo desta tese é realizar uma análise econômica sobre a compensação financeira pela exploração dos recursos minerais no âmbito do novo Código de Mineração. Através de um modelo de equilíbrio geral computável, foram simulados os potenciais impactos do aumento na carga tributária incidente sobre a indústria de mineração, considerando seus efeitos sobre a economia nacional e sobre os principais estados brasileiros produtores de minério. Os resultados encontrados apontam que, apesar da queda no investimento e na produção da indústria mineral, o aumento dos gastos públicos regionais deve aquecer as economias locais, gerando renda e elevação de preços. Entretanto, o modelo adotado na simulação não considera que mudanças na base de cálculo da CFEM podem mudar o comportamento dos mineradores e que os novos recursos da compensação podem alterar a política fiscal dos governos contemplados. Para avaliar a primeira possibilidade, foram analisados modelos teóricos que indicam que o novo arcabouço regulatório está caminhando no sentido contrário da neutralidade do arranjo tributário, o que, a princípio, não é desejável. No entanto, tendo em vista que a assimetria de informação entre investidor privado e regulador também gera perdas ao poder público, sugere-se um arranjo alternativo para a CFEM, onde ela é composta por um componente fixo e um componente ad valorem, sendo que os valores pagos em cada modalidade pelo minerador devem ser definidos no leilão que atribuirá às jazidas minerais aos investidores interessados. Por fim, foram avaliados os impactos da CFEM na política fiscal dos municípios contemplados vis-à-vis o comportamento dos municípios não contemplados. Para isso, foram estimados diversos modelos econométricos elaboradas com base em um propensity score weighting espacial. São testados os efeitos da CFEM sobre o esforço fiscal dos municípios, sobre a contratação de empregados no setor público e sobre os gastos públicos correntes das prefeituras. Os resultados encontrados apontam que, em geral, as rendas da CFEM: (i) diminuem o esforço de arrecadação próprio dos municípios; (ii) aumentam a contratação de pessoal no setor público; e (iii) provocam uma expansão dos gastos públicos correntes significativamente maior do que aquela resultante de aumentos da renda per capita dos contribuintes, o chamado efeito flypaper. Com base nestes resultados, é sugerida a adoção de um Fundo de Recursos Soberanos para a administração federal dos recursos da CFEM, sendo que os estados e municípios beneficiados seriam cotistas do fundo, mas resgatariam os recursos sob algumas regras pré-definidas / In June 2013, the Brazilian Government sent to the Congress a proposal for the new regulatory framework of the mining sector, which includes an increase in royalties paid by mining companies. Critics of this proposal argue that this increase does not occur under a broader tax reform. Therefore, the new tax can rise the extraction cost of some minerals in Brazil, hampering the integration of companies into the international market and hence discouraging productive investment in the country. The aim of this thesis is to conduct an economic analysis of the financial compensation for the exploitation of mineral resources (CFEM) under the new Mining Code. Through a general equilibrium model, it simulated the potential impact of the increased royalties on the mining industry, considering their effects on the national economy as well as on the main Brazilian mining states. Results show that despite the falling investment and production on the mining industry, the rise of regional public spending should boost local economies, generating income and higher prices. However, the model adopted in the simulation does not take into account that changes in the CFEM\'s calculation basis can affect the behavior of miners and that the new revenues can change the fiscal policy of benefiting governments. In order to assess the first possibility, theoretical models were analyzed, whose results indicate that the new Mining Code is moving away from a neutral taxation arrangement, which is not desirable. However, since the information asymmetry between investor and regulator also generates losses to the government, it is suggested a new alternative, which consists in a two-component CFEM: a fixed one and a variable one. The proportions of each component should be set by auctions in order to allocate mineral rights to interested investors. With the purpose of considering the second hypothesis, the impacts of CFEM on the fiscal policy of the municipalities were analyzed. In order to do so, several econometric models based on a spatial propensity score weighting are estimated. The effects of CFEM on the tax effort of the municipalities, on the hiring of employees by the public sector and on the current public spending of municipalities are tested. Results show that, in general, CFEM rents: (i) decrease the effort of municipalities; (ii) increase the hiring in the public sector; and (iii) cause an expansion of current public spending significantly higher than that resulting from increases in income per capita (flypaper effect). Based on these results, it is suggested the adoption of a Sovereign Resources Fund for federal administration of CFEM. States and municipalities should be shareholders of the fund, but some predefined rules to rescue resources should be observed

Objetivando-se estudar o efeito da suplementação mineral no desenvolvimento reprodutivo de bubalinos do desmame aos 24 meses de idade, utilizaram-se 110 búfalos, distribuídos em três experimentos (A, B e C), que foram criados em três propriedades (GA, GB e GC) no Estado do Pará. Os experimentos A e B foram realizados em áreas de terra firme com pastagens cultivadas (Brachiaria brizantha cv. Marandu) em manejos rotacionado e extensivo, respectivamente, com capacidade de suporte e perfil nutricional da forragem, semelhantes. O experimento C foi desenvolvido em áreas de várzea na Ilha de Marajó, com pastagens nativas constituídas, principalmente, por Panicum sp, Axonopus sp e Paspalum sp. Em todas as propriedades dividiram-se os animais em dois grupos (experimento A: GA1 e GA2, experimento B: GB1 e GB2, e experimento C: GC1 e GC2) que foram mantidos a pasto com diferentes suplementações minerais. Os animais foram pesados a cada 28 dias e receberam distintos suplementos minerais: grupos GA2 e GB2 mistura mineral, a ser testada, indicada para búfalos; grupos GA1 e GB1 - misturas minerais utilizadas rotineiramente na fazenda e recomendadas para bovinos; GC1 animais não suplementados e GC2 mistura mineral indicada para búfalos criados em áreas de várzea com águas salobras. As sobras da mistura mineral foram recolhidas semanalmente para se calcular o consumo real da mesma. A cada 56 dias as circunferências escrotais, comprimentos, larguras e espessuras dos testículos foram mensurados, como também foi avaliada a disponibilidade quali-quantitativa da forragem. Aos 22 meses de idade, 77 búfalos foram submetidos a colheitas de sêmen semanais, nos meses de maio e junho de 2005 (n = 616 amostras de sêmen), através de eletroejaculação para se analisar as características físico-morfológicas do sêmen. No plasma seminal foram, determinadas as concentrações de Ca, P, Mg, Cu, Co, Fe, Zn e Mn. Após 14 meses de estudos constatou-se que tanto os animais do grupo GA2 como os do GB2 obtiveram um maior ganho de peso médio diário (p<0,0001). O grupo GA1 consumiu uma maior (p<0,0001) quantidade de mistura mineral, enquanto que para os grupos GB1 e GB2 não houve diferença significativa. As medidas testiculares do grupo GA2 foram significativamente maiores, ao final do estudo, do que as do grupo GA1, demonstrando com isso um efeito da suplementação mineral sobre estas variáveis. Para o grupo GB2 a espessura, a largura e o volume testicular foram significativamente maiores. As demais medidas não sofreram variações significativas. No experimento C não houve variação entre o peso e o ganho de peso para ambos os grupos. Isso provavelmente esta relacionado ao baixo consumo de mistura mineral pelo grupo GC2. Essa pequena diferença do peso entre os grupos GC1 e GC2 foi acompanhada por uma diferença não significativa nas medidas testiculares dos grupos. Deduz-se que devido as altas correlações positivas entre a circunferência escrotal (CE), o peso corporal e demais medidas dos testículos, a CE possa ser utilizada para predizer o tamanho testicular. Conclui-se ainda que a suplementação mineral testada exerceu efeito positivo sobre o peso e o ganho de peso médio diário dos animais dos experimentos A e B. Evidenciou-se médias significativamente maiores para as características físicas do sêmen dos animais que receberam a suplementação mineral testada (GA2) com exceção da concentração espermática. Para as características morfológicas do ejaculado, observou-se que os animais do grupo GA1 apresentaram médias significativamente maiores para o número total de espermatozóides anormais. Não foram verificadas diferenças significativas nas características físicas e morfológicas do sêmen dos grupos GB1 e GB2, com exceção do volume do ejaculado e da motilidade progressiva que foram significativamente maiores para os animais do grupo GB2. Observaram-se correlações significativas, porém baixas, entre a CE a algumas características do ejaculado. Conclui-se, portanto que houve influência da suplementação mineral nas características físicas e morfológicas do sêmen dos animais do experimento A, com melhores resultados para o grupo GA2, que consumiram a suplementação mineral testada; constatou-se, ainda, uma tendência de uma melhor qualidade no sêmen dos animais do grupo GB2. Foi possível averiguar que não houve diferença significativa para os constituintes macro e microminerais do plasma seminal de búfalos jovens, criados em pastejo rotacionado, exceto para os níveis de manganês que foram significativamente maiores para os animais do grupo GA2. Obtiveram-se os seguintes valores para Ca (14,32 ± 6,40 mg/dl), P (3,86 ± 3,30 mg/dl), Mg (11,64 ± 7,02 mg/dl), Zn (4,23 ± 1,35 &mu;g/ml), Fe (8,23 ± 2,38 &mu;g/ml), Cu (0,17 ± 0,07 &mu;g/ml), Co (0,06 ± 0,04 &mu;g/ml) e Mn (0,08 ± &mu;0,06 g/ml) contidos no plasma seminal de búfalos criados em pastejo rotacionado. Os animais do grupo GB2 apresentaram maiores níveis de fósforo e cobalto do que os do grupo GB1, que por sua vez obtiveram maiores teores de manganês. Encontraram-se os seguintes valores Ca (12,16 ± 2,97 mg/dl), P (4,01 ± 4,46 mg/dl), Mg (11,37 ± 6,48 mg/dl), Zn (4,02 ± 1,39 &mu;g/ml), Fe (6,73 ± 1,80 &mu;g/ml), Cu (0,07 ± 0,03 &mu;g/ml), Co (0,14 ± 0,06 &mu;g/ml) e Mn (0,17 ± 0,11 &mu;g/ml) contidos no plasma seminal de búfalos criados em sistema extensivo. Muito embora alguns minerais tenham apresentado correlações significativas com algumas características do ejaculado, essas foram baixas. Portanto não se observou uma variação quali-quantitativa nas concentrações físicas e morfológicas do ejaculado de búfalos jovens criados em pastejo rotacionado e sistema extensivo, em função da concentração de minerais no plasma seminal. / To objectify the study of the effect of mineral supplementation in the reproductive development of buffaloes of wean in the 24 months of age, were used 110 buffaloes, distributed in three experiments (A, B e C) created in three farms (GA, GB e GC) in the Para State. The experiments A e B were realized in areas of firm soil with cultivated pasture (Brachiaria brizantha cv. Marandu) in rotational and extensive management, respectively, with similar capacity of support and nutritional profile of the forage. The experiment C was developed in tilled plain areas in Marajo Island, with native pasture basically formed by Panicum sp, Axonopus sp e Paspalum sp. In all farms the animals were divided in two groups (A: GA1 e GA2 experiment, B: GB1 e GB2 experiment, and C: GC1 e GC2 experiment) which were maintained in the pasture with different mineral supplements. The animals were pondered in each 28 days and received different mineral supplements: GA2 and GB2 groups mineral blend, to be tested, indicated to buffaloes; GA1 and GB1 groups mineral blend used in a regular procedure in the farm and recommended to bovines; GC1 group not supplemented animals and GC2 group mineral blend indicated to buffaloes created in tilled plain areas with salutary waters. The remaining mineral blends were collected weekly to calculate the real use of the blends. In each 56 days the scrotal circumferences, lengths and widths of the testis were measured, and was evaluated the availablebility of the quality and the quantity of the forage, as well. In the 22 month of age, 77 buffaloes were submitted to weekly semen collects, in May and June of 2005 (n = 616 semen samples), trough electroejaculation to analyze the semen physic and morphologic characteristics. In the seminal plasma were determined the Ca, P, Mg, Cu, Co, Fe, Zn e Mn concentration. After 14 months of research both animal groups (GA2 and GB2 groups) got larger diary medium weight gain (p<0,0001). The GA1 group has consumed a larger (p<0,0001) quantity of mineral blend, although to the GB1 and GB2 groups there wasnt any significative difference. The testicular measurements of GA2 group were significatively larger, at the end of the research, as the GA1 group, proving that the effects of mineral supplement on these variants. To the GB2 group the thickness, the width and the testicular volume were significatively larger. The others measurements havent significant variations. In the C experiment there wasnt any variation between the weight and gain of weight to both groups. This is probably connected to low use of mineral blend by GC2 group. This insignificant difference of the weight between GC1 and GC2 group was followed by an insignificant difference in the testicular measurements of the groups. Due to high positive correlations between the scrotal circumference (SC), the weight of the body e others measurements, deduce that the SC can be used to predict the testicular size. It can be concluded, as well, that the tested mineral supplement carried out a positive effect on the weight and the gain of diary medium weight of the animals in the experiments A and B. The research proved significant bigger mean rates to the physical characteristics of the animals semen that received the tested mineral supplement (GA2) with exception of spermatic concentration. To the morphological characteristics of semen, it observed that the GA1 animal group showed significant mean rates larger to the total number of abnormal sperm. Significant differences werent noted in the physical and morphological characteristics of the semen of GB1 and GB2 groups, with exception of the volume of the semen and of the motility progressive which were significatively larger to the animals of GB2 group. Significant, but low correlations between the SC and some characteristics of the semen were observed. Consequently, it can be concluded, there were influence of the mineral supplement in the physical and morphological characteristics of the animals semen of A experiment, with better results to GA2 group , that consumed the tested mineral supplement; a tendency of a better quality of the animals semen of the GB2 group animals. Was possible to verify there werent important difference to the macro and micro mineral constituents of the seminal plasma of young buffaloes, created in rotational pasture system, except to the levels of manganese which were significatively larger to the GA2 group animals. The next values were obtained: to Ca (14,32 ± 6,40 mg/dl), P (3,86 ± 3,30 mg/dl), Mg (11,64 ± 7,02 mg/dl), Zn (4,23 ± 1,35 &mu;g/ml), Fe (8,23 ± 2,38 &mu;g/ml), Cu (0,17 ± 0,07 &mu;g/ml), Co (0,06 ± 0,04 &mu;g/ml) e Mn (0,08 ± 0,06 &mu;g/ml) contained in the seminal plasma of the buffaloes created in rotational pasture system. The GB2 group animals introduced larger levels phosphorus and cobalt than the GB1 group, which obtained larger values of manganese. The following values were also discovered: Ca (12,16 ± 2,97 mg/dl), P (4,01 ± 4,46 mg/dl), Mg (11,37 ± 6,48 mg/dl), Zn (4,02 ± 1,39 &mu;g/ml), Fe (6,73 ± 1,80 &mu;g/ml), Cu (0,07 ± 0,03 &mu;g/ml), Co (0,14 ± 0,06 &mu;g/ml) e Mn (0,17 ± 0,11 &mu;g/ml) contained in the seminal plasma of the buffaloes created in extensive system. In spite of some minerals have presented significant correlations with some characteristics of the semen, these ones were lows. Then a variation of the quality and the quantity of physical and morphological concentrations of the semen of young buffaloes created in rotational pasture system and extensive system werent observed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os minerais estão presentes no cotidiano humano sob as mais variadas formas, seja no campo da metalurgia, da indústria química, da construção civil ou do cultivo da terra. De uma maneira geral, constata-se que o caminho trilhado pelo desenvolvimento da humanidade foi e é alcançado mediante a busca e utilização de bens minerais. Dada a extensão territorial e a diversidade geológica encontrada no solo e subsolo, o Brasil apresenta como detentor de importante potencial minerário no cenário mundial. Nesse contexto, Roraima constitui-se numa região que foi tradicionalmente voltada à exploração de bens minerais, sobretudo ouro e diamante. Principal porto fluvial do estado de Roraima, muito importante em passado recente, o município de Caracaraí RR perdeu sua função axial com a construção da rodovia BR-174. O desenvolvimento de sua zona rural está baseado na pecuária, o núcleo urbano no comércio e serviços e o setor minerário ainda incipiente. Este estudo enfoca um levantamento dos recursos minerais de importância econômica, inclusive os que estão em fase de exploração no município, utilizando como meios auxiliares produtos de sensoriamento remoto e dados de campo. Foram pesquisados 19 pontos amostrais, sendo oito nas proximidades da BR-174 e 11 em bibliografias consultadas. Foram confeccionadas cartas imagens de ocorrências minerais, substâncias minerais e de mineração em atividade. Caracaraí possui áreas de potencial mineral, tais como areia, seixo, argila, granito e laterita, com ocorrências de ouro. Outros minerais têm sido descobertos na forma de pequenos depósitos ainda pouco investigados, porém as áreas destinadas às terras indígenas e conservação ambiental, conduzem à redução da exploração dos mesmos, além de criar barreiras impedindo os avanços no conhecimento geológico e nas descobertas de novas ocorrências minerais no município. / The minerals are present in everyday human under the most varied forms, whether in the field of metallurgy, chemical industry, construction or farming. In general, it appears that the path followed by the development of humanity was and is achieved by seeking and use of mineral commodities. Given the territorial extension and geological diversity found in soil and subsoil, Brazil has great potential as a holder of mining on the world stage. In this context, Roraima is in a region that has traditionally focused on the exploitation of minerals, especially gold and diamonds. Main river port in the state of Roraima, very important in the recent past, the city of Caracaraí - RR lost its axial with the construction of highway BR-174. The development of their rural area is based on farming, the urban core in trade and services and the mining industry still in its infancy. This study focuses on a survey of economically important mineral resources, including those in the exploration stage in the city, using as auxiliary products of remote sensing and field data. We surveyed 19 sampling points, eight near the BR-174 and 11 in bibliography. Images were prepared letters of mineral occurrences, mineral and mining activity. Caracaraí has areas of mineral potential, such as sand, gravel, clay, granite and laterite, with gold occurrences. Other minerals have been discovered in the form of small deposits still poorly investigated, but the areas allocated to indigenous lands and conservation, leading to reduce the exploitation of them and create barriers impeding progress in geological knowledge and discoveries of new mineral occurrences in the city.

Zinkgruvan is a Pb-Zn-Ag deposit located in south-central Sweden, owned and operated by Lundin Mining. The ore is beneficiated by a collective-selective flotation circuit, recovering both galena and sphalerite in a bulk rougher-scavenger flotation stage and later on separating them into two final products. Opportunities for increase in zinc recovery in the bulk rougher scavenger flotation stage have been identified as the plant is relying on natural Pb-activation to process the ore. Process mineralogical tools were used to characterize four different orebodies from Zinkgruvan (Burkland, Borta Bakom, Nygruvan and Sävsjön) and evaluate the metallurgical performance for flotation and magnetic separation, following a geometallurgical approach to better understand and predict the behavior of such ore types in processing plant. The first hypothesis in this thesis is that by addition of copper sulfate and increased collector dosage, Zn recovery will be improved without being detrimental to galena flotation. Results demonstrated that there is a significant increase in Zn recovery by further increasing collector dosage and copper-activating the flotation pulp in the scavenger stage. For instance, an increase in zinc recovery up to 16% has been achieved after addition of copper sulfate. Galena is readily floatable while sphalerite takes longer to be recovered. In addition, iron sulfides take longer to be recovered and, after addition of copper sulfate, there was an increase in iron sulfide recovery. The amount of iron sulfides reporting to the concentrate should still not be a problem to the plant. Most of the Fe in the concentrate is still coming from the sphalerite lattice. However, it might be that some orebodies coming into production in the near future have higher amounts of pyrrhotite, which might be a problem. Therefore, magnetic separation methods have been tested to remove pyrrhotite from the bulk ore. The second hypothesis is that the high Fe content in the concentrate might be due to the presence of iron sulfides, in which case they could be selectively removed by magnetic separation. XRD analyses demonstrated that Sävsjön is a highly variable orebody, and that its high Fe content varies with the location inside the orebody, being caused by either iron sulfide or iron oxide minerals. Both monoclinic and hexagonal pyrrhotite have been observed. Davis Tube could remove monoclinic pyrrhotite but it was very inefficient when dealing with hexagonal pyrrhotite. WHIMS, on the other hand, performed well for both types of pyrrhotite. When applying Davis Tube on Sävsjön OLD feed, a concentrate with up to 52.3% pyrrhotite is achieved, at a recovery of 35.32%. However, sphalerite is also reporting to the magnetic concentrate, which would generate Zn losses for the overall process. Zinc losses were up to 15.3% when the highest field strength was applied. Therefore, the applicability of magnetic separation for Zinkgruvan ore must be further evaluated.

A gradual depletion of high-grade ores, coupled with the growing demand for mineral commodities across the world has culminated in the increased exploitation of lean-grade ores with complex mineralogy. The mineral processing industry commonly uses an extensive range of inorganic, naturally derived or synthetic organic reagents in the separation of valuable minerals from the ore. Froth flotation is a commonly used separation technique to float or depress different sulfide minerals from the ore, based on their surface properties. In recent times, biological processes have been attracting attention in mineral processing and metal recovery operations due to a number of factors, especially lower operating costs, lesser energy consumption and their environment friendly nature. The use of microorganisms and their direct derivatives in mineral processing, hydrometallurgy and in the bioremediation of mineral industry discharges has led to the emerging area of “Mineral Bioprocessing”. In this study, a family of four microorganisms belonging to the Bacillus species, viz., Paenibacillus polymyxa, Bacillus circulans, Bacillus megaterium and Bacillus subtilis was used to ascertain the selective floatability of sphalerite from a sphalerite-galena mineral mixture. These bacteria are Gram positive, mesophilic, neutrophilic, aerobic and spore forming. The major objectives of the investigation include: a) Identification and characterization of bioreagents derived from Bacillus species for the flotation of sphalerite from a sphalerite-galena mixture b) Optimization of the flotation process for the enhanced recovery of sphalerite using specific bioreagent combinations c) Modes and mechanisms of bacterial adaptation to minerals and their consequent effects on the flotation of sphalerite and galena d) Elucidation of the mechanisms of microbe-mineral interactions and the role of extracellular secretions in sphalerite flotation column and their N-terminal residues were identified using Edmann N-terminal sequencing. Additionally, sequences of several internal peptides from both the proteins were determined using Tandem Mass Spectrometric techniques. A database search revealed that the sequences of these peptides are unique and have not been reported earlier. It was established that the bacterial cells give high flotation recovery of sphalerite under buffered conditions and that it took place only in the presence of anionic buffers. Additionally, the viability of the bacterial cells was not required for the flotation of minerals. A major finding of this study was that other than extracellular DNA (eDNA), none of the other bacterial surface components like teichoic acids, surface proteins, polysaccharides played a positive role in the flotation process. Nucleic acids, more particularly single stranded DNA (ssDNA), facilitated sphalerite flotation relative to double stranded DNA (dsDNA). A probable mechanism of ssDNA -mediated selective flotation of sphalerite has been presented. A negative role for non-DNA surface components was also observed. This led to the realization of the need for an optimum ratio of DNA to non-DNA components in the selective flotation of sphalerite from a sphalerite-galena mixture. It was found that the surface physiochemical properties of the mineral adapted bacteria differed significantly from that of the unadapted bacteria. Adaptation enhanced the flotation recoveries of the corresponding mineral vis-à-vis the unadapted bacteria. Sphalerite adapted bacteria secreted more extracellular proteins while the galena adapted bacteria secreted more polysaccharides compared to the unadapted bacteria. Sphalerite adapted bacteria selectively floats more sphalerite from the mineral mixture than the galena adapted as well as the unadapted bacteria. It was evident from the electrokinetic studies that the surface charge of the chosen sulfide mineral adapted bacteria was less negative relative to the unadapted bacteria. This phenomenon was observed with all the four bacterial species used in this study. A noteworthy finding was that the bacteria especially B.circulans induce a change in morphology from rod to sphere as a strategy during adaptation to a toxic mineral such as galena. This phenomenon has been shown to involve changes in crucial cell wall components as well as changes in the levels of expression of bacterial cytoskeleton elements involved in the maintenance of the rod shape. This aspect of the study involved the partial sequencing of the B.circulans homolog of the key cytoskeleton gene, mreB (B gene in murien cluster e), using the Polymerase Chain Reaction (PCR) followed by DNA sequencing. A Genbank search indicated that this is the first report of the sequence of B.circulans mreB gene. This was followed by measuring the hypothesized downward changes in the levels of expression of the mreB gene by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). The possible mechanisms of the adaptive morphological changes and of the interaction of the chosen sulfide minerals with the family of microorganisms studied have been discussed with respect to their bioflotation efficiency.

M.Comm. (International Taxation) / Lyn Bourne (n.d.) once wrote "The concept of royalties evolved from a time when the government owned all of the land, including mines, to the situation where free miners won the right to claim minerals, but paid a portion of their production to the royal treasury. Today, a mineral royalty is a payment to the owner of the mineral rights for the privilege of producing the mineral commodity"...

No description available.

Call number: LD2668 .T4 1948 R4 / Master of Science

When mining companies extract minerals from the earth, they leave huge deposits of soil and ore next to the mining site. These deposits are commonly known as tailings. In most instances, tailings contain a considerable amount of valuable mineral resources which cannot be exploited because of a lack of appropriate equipment, or as a result of economic non-viability. However, many mining companies choose to keep and maintain these tailings, in the hope that such minerals can later be exploited when time or technology allows for this. Under common-law the owner of a property is considered to also own any minerals contained on the property, in terms of the principle of cuius est solum. In South African law, however, a practice evolved whereby owners of minerals separated rights to minerals from the surface rights on the property. This created a mining right which was independent from the land and could be transferred to third parties, often in return for compensation. Under the Minerals Act of 1991 the owner of a mining right over a property (be that the owner of the property or a third-party mining right holder) also held the mining right to tailings which were created as a result of mining activities under the right. Thus, if a mining company performed mining activities on a property, the company was also free to exploit the tailings which were left next to its mine, regardless of whether the dump had remained there for a long period of time. Owing to South Africa's long history of mining, some tailings are over a century old and resemble small mountains rather than mining deposits. The Mineral and Petroleum Resources Development Act of 2002 changed the entire mineral legislative regime in South Africa. Whereas owners of land were previously free to separate and sell their rights to minerals to anyone they wished, the MPRDA placed the country‟s mineral and petroleum resources under the state's "custodianship." Where the law talks about custodianship, however, it supposedly refers only to minerals that have not yet been extracted from the earth. It is well established in South African law that, once a mineral is extracted, it becomes the movable property of the person who extracted it – in other words, that of the mining company. Does this mean that minerals in tailings also fall under the state's custodianship? The Free State High Court did not think so. In the case of De Beers v Ataqua it held that, in terms of the common law principles of acquisition by way of attachment, tailings are clearly movable property and therefore belong to the mining company who created them. For the MPRDA to hold otherwise would amount to expropriation. The state did not wish for some mining activities to be regulated by a different set of legislation, so it amended the MPRDA to try and define "residue deposits" (the name by which the MPRDA calls tailings) more clearly. However, due to the legislature's unfortunate choice of wording, tailings created before the enactment of the MPRDA are still, strictly speaking, not regulated by that Act. So the legislature proposed another amendment to the Act, this time making sure that any historical mine dump created at any point in South Africa's history are placed under the Act's regime. The subject matter of this study is whether the above amendments to the MPRDA could be considered to be expropriation. For background purposes, a brief overview of the Ataqua decision as well as the subsequent amendments to the MPRDA will be given. Then the history of mining legislation and the development of a separate mining right will be summarised. The reason for this summary is to establish whether, in terms of constitutional litigation, a clear right has been established for purposes of protection under section 25 of the Constitution. The last phase of the study will look at the particular characteristics of expropriation and ask the question whether acquisition of a right by the state is always a fundamental requirement for expropriation to take place. It is submitted that the destruction of an entire class of property by way of legislation, amounts to so-called "institutional expropriation," which is subject to compensation in terms of section 25. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2015