An investigation of the literature showed that as the diameter of a hydrocyclone was decreased, smaller particles could be effectively separated on the basis of specific gravity. Consequently, a laboratory scale study was conducted to determine the possibility of removing pyritic sulfur from fine coal using a 1.0" diameter hydrocyclone. A 1.0" diameter hydrocyclone was constructed from stainless steel. The hydrocyclone was fabricated with easily interchangable parts that permitted rapid variations in the inlet diameter, apex discharge diameter, vortex finder diameter, vortex finder position, and cone angle. The feed pressure to the hydrocyclone could also be varied. A recirculating system was used. Synthetic material was used in place of actual coal during this investigation. The synthetic material, made from casting resin and barium sulfate, duplicated the coal with respect to particle size, shape, and specific gravity distribution. The synthetic coal had the advantage of not degrading during the course of the experiment. Three coals were simulated for the purposes of this experiment. Pocahontas 113 coal served as the "light" coal, the Hagy seam was selected as the "medium" coal, and coal from the Cortes area of New Mexico was chosen as the "heavy" coal. By optimizing the 1.0" diameter hydrocyc1one for these three coals, it would be possible to extend the results of the investigation to any coal. The results of the investigation showed that the 1.0" diameter hydrocyclone was an effective device for removing pyritic sulfur from 65 x 200 mesh coal. The results for the minus 200 mesh size fraction were not good. A smaller diameter hydrocyclone would be necessary in order to effectively process the minus 200 mesh size fraction. / Ph. D.

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Made available in DSpace on 2016-12-08T15:50:02Z (GMT). No. of bitstreams: 1 PGMS13DA013.pdf: 4154181 bytes, checksum: a22d139b7488a1e1217d480134dbbc47 (MD5) Previous issue date: 2013-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work was developed in three distinct phases, the first phase evaluated the soil fauna in reclaimed areas after coal mining open pit, in the second evaluated the ecological risk of the waste pyritic (coal more pyrite) generated from coal mining, and the third phase was conducted ecological risk assessment (ERA) of São Domingos copper and iron mine (SDM; Portugal). The first phase aims to evaluate the richness and abundance in constructed soils after coal mining open pit in the region of Lauro Müller/SC. Soil fauna was collected using a cylinder of 17 cm diameter, 5 cm depth, and evaluated by the Berlese method, followed by the identification of organisms. The results obtained in this study indicate that soil fauna suffered influences of treatments and therefore can be used as a bioindicator of changes caused by land reclamation. The second phase aims to evaluate the ecotoxicological effects of depositions of waste pyritic. For this, used soils collected in Lauro Müller (LM) and Capão Alto (CA), this waste tested five doses (0.0, 2.5, 5.0, 10.0, 20.0%) and conducted avoidance tests with Folsomia candida and Eisenia andrei, survival and reproduction with F. candida, E. andrei and Enchytraeus crypticus and germination with Avena sativa and Lotus corniculatus. The organisms studied showed different sensitivities and the results indicate that the pyritic waste has the potential to negatively affect soil organisms, both in short period of time (avoidance test) and long-term (survival and reproduction). In the third phase, the ERA of MSD aims to get information of the spatial distribution of metal and arsenic contamination, integrating information from the chemical line of evidence (metal analysis and calculation of toxic pressures) and the ecotoxicological line of evidence (Vibrio fischeri solid-phase test, Folsomia candida avoidance test and Avena sativa seed germination test). As predicted, integrated risk values decreased with increasing distance from the CA. However, the risk uncertainty still persisting at some points and therefor suggest a more detailed evaluation, which will constitute the next stage of the risk assessment / O presente trabalho foi desenvolvido em três fases distintas, sendo que na primeira fase avaliou-se a mesofauna do solo em áreas recuperadas após mineração de carvão a céu aberto, na segunda avaliou-se o risco ecológico do resíduo piritoso (carvão mais a pirita) gerado da mineração de carvão, e na terceira fase foi realizada análise de risco ecológico (ARE) da Mina de cobre e ferro de São Domingos (MSD; Portugal). A primeira fase objetivou avaliar a presença da mesofauna edáfica em solos construídos após a mineração de carvão a céu aberto na região de Lauro Müller/SC. A fauna do solo foi coletada utilizando-se um cilindro de 17 cm de diâmetro, na profundidade de 5 cm, e avaliada pelo o método de Berlese, seguido da identificação dos organismos. Os resultados obtidos evidenciam que a fauna do solo teve influencia dos tratamentos e por isso pode ser utilizada como bioindicador das alterações ocasionadas pela recuperação do solo. A segunda fase objetivou avaliar os efeitos ecotoxicológicos das deposições de resíduo piritoso. Utilizaram-se solos coletados em Lauro Müller (LM) e Capão Alto (CA), testadas cinco doses desse resíduo (0; 2,5; 5; 10; 20%). Realizou-se testes de fuga com Folsomia candida e Eisenia andrei, de sobrevivência e reprodução com F. candida, E. andrei e Enchytraeus crypticus e de germinação com Avena sativa e Lotus corniculatus. Os organismos e as plantas estudados apresentaram diferentes sensibilidades e os resultados indicam que o resíduo piritoso apresentou potencial de influenciar negativamente os organismos do solo, tanto em curto período de tempo (teste de fuga) quanto em longo prazo (sobrevivência e reprodução). Na terceira fase, a ARE da Mina de São Domingos objetivou obter informações da distribuição espacial da contaminação por metais e arsênio, integrando informações a partir das linhas de evidência química (análise de metais e arsênio e cálculo de pressões tóxicas) e ecotoxicológica (teste em fase sólida com Vibrio fischeri, teste de fuga com F. candida e teste de germinação de sementes com A. sativa). Como previsto, o valor de risco integrado diminuiu com o aumento da distância dos pontos coletados. No entanto, incertezas em relação ao risco ainda persistem em alguns pontos e, portanto, sugere-se uma avaliação mais detalhada, que constituirá a próxima fase da avaliação de risco

Oxidation of pyrite can significantly affect properties and the behavior of soil and rock in civil construction. Problems with pyritic rock and soil extend globally and across many disciplines. Consequences of pyrite oxidation include heave, concrete degradation, steel corrosion, environmental damage, acid mine drainage, and accelerated weathering of rock with concomitant effects on strength and stability. Affected disciplines include soil science, mining, engineering geology, geochemistry, environmental engineering, and geotechnical engineering. While pyrite problems may be well known in their respective disciplines, there has been to date relatively little cross-disciplinary communication regarding problems with pyritic geomaterials. Thus, there is a need to establish an inter-disciplinary and inter-regional awareness regarding the effects of pyrite oxidation and their prevention or mitigation. This engineering research is a compilation of information about geotechnical problems and engineering behavior of pyritic rock and soil, the underlying physicochemical processes, site investigation strategies, and known problematic formations. Several case histories documenting consequences of pyrite oxidation are provided. The results of chemical analyses performed on pyritic shale samples from a formation with acknowledged heave problems are presented. Digital data and ESRI's ArcGIS digital mapping program were used to create maps showing results of sampling and testing performed during this study. Appendices include mitigation options, results of a practitioner survey, chemical test procedures, a glossary, a visual identification key for sulfidic geomaterials, and a summary table of the literature review for this research. / Master of Science