Anthropogenic and geogenic sources of arsenic (As) have been identified in mining-impacted soils from the Giant mine (1948-1999), NT and the North Brookfield mine (1886-1906), NS. Both used roasting to extract gold from the arsenopyrite ore, decomposing it to As-bearing iron oxides (roaster oxides or RO) containing As, and releasing As3+-bearing arsenic trioxide (As2O3). Arsenic trioxide is considered highly soluble with the dissolved As3+ species being more mobile and toxic than other oxidation states. Soil profiles from the Giant mine show elevated As and antimony (Sb) at the surface (As=140-3300ppm) and decreasing concentrations with depth (As=22-600ppm). Surface soils contain anthropogenically-derived As2O3 identified using synchrotron methods (µXRD, µXANES) and environmental SEM. The persistence of As2O3 is attributed to Sb in As2O3 grains, dry climate and high organics in the soils. Anthropogenically-derived RO of maghemite (containing both As3+ and As5+) and natural arsenopyrite were observed. Sequential selective extractions (SSE) from surface soils show between 20% and 75% of As extracted in the crystalline iron-oxide phase is attributed to As2O3 and RO, while at depth As is bound by organics in the weaker leaches. North Brookfield mine soils show lower total As (2ppm to 45ppm) except near the roaster (4300ppm). No As2O3 was identified, probably due to the smaller scale and age of the mine, lower organic content and the lack of Sb. As-bearing phases include RO of hematite (As5+), As-rich rims on titanium-oxides, and As associated with clays and goethite. Adjacent to the roaster, SSE show As was also in the amorphous iron-oxide phase, also shown by As in arsenopyrite weathering rims. There are many differences between the North Brookfield and Giant mine soils including roasting techniques which produced different RO mineralogy, the scale of mining, climate, soil type, and the presence of As2O3. Currently, the Giant property is not publically accessible but may become so in the future while the North Brookfield property is accessible. Understanding the form and distribution of As phases is critical because of the potential risk to human and ecosystem health associated with ingestion of soil particles and their control on the total dissolved As in surface and groundwater. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2008-09-29 17:21:50.73

Potential new ore deposits containing significant levels of enargite, a copper arsenic sulphide mineral, are being considered for development. The processing of high arsenic copper concentrates directly in copper smelters is difficult due to environmental concerns. This thesis investigates a process using sulphation roasting as an alternative method for processing enargite concentrates; copper is recovered from the calcine by acid leaching, gold is extracted from the leach residue by conventional cyanidation and arsenic is either fixed in the calcine or precipitated from process emissions. In this research, sulphation roasting between the temperatures of 300-800oC, with varying oxygen and sulphur dioxide partial pressures, was investigated. Experiments indicated that high levels of copper extraction, as well as arsenic fixation, could be achieved from the produced calcines through hydrometallurgical processes. At operating temperatures between 400-550oC copper sulphate, copper arsenate, iron sulphate, hematite and iron arsenate form in the calcine, as well as some arsenic being volatilized as arsenic trioxide. At processing temperatures between 475-575oC, greater than 80% of the arsenic was retained in the calcine as copper and iron arsenates. Copper arsenate would be weak-acid soluble and fixed in an effluent treatment plant along with arsenic captured in the wet-gas scrubber bleed solution. As operating temperatures increase above 650oC copper sulphates were converted into oxysulphates, oxides and ferrites, hematite production was favoured, and arsenic was primarily volatilized. Increasing the sulphur dioxide addition in the reaction atmosphere resulted in additional sulphate formation and increased sulphate stability at higher temperatures. Sulphation roaster heat balances were developed for calcines produced at two temperatures, 500 and 750oC. They indicated that while high copper extraction and arsenic fixation rates could be achieved, the sulphation roasting reactions are highly exothermic and significant cooling water would need to be added. Due to these issues, it is likely that partial roasting operations would be economically favourable in greenfield operations. However, niche applications of this process in operations with existing copper SX/EW facilities in good acid markets, have the potential to be economically favourable. / Thesis (Master, Mining Engineering) -- Queen's University, 2012-08-17 20:14:36.292

One of the objectives of my thesis is to argue that regulatory capitalism and international law are problematic forms of power implicated both directly and ideologically in the standardizing practices and regulation of certified fair trade. My work begins by explaining variations in the way fair trade coffee is conceptualized and offered in the market, then moves on to explain how fair trade certification standards link up with other international standards and certification bodies, and finally, describes how standards and certification are used to textually construct social facts. I examine first those places where regulatory capitalism and international law remain embedded and active in fair trade certification practices, then the way standardizing practices work to organize (or disorganize) the relationships of people who work with fair trade coffee. The ethnography consists of interviews with three informally regulated fair trade roasters in the Victoria region. My aim is to identify precisely the points where the standardizing practices of certified fair trade reduce concrete relations of exchange to conceptual notions of fair trade. Identifying these points allows me to examine areas where dominant forms of power remain embedded and active in the concept and realization of certified fair trade coffee, and also how standardizing practices limit the potential of fair trade to transform unjust relations of trade. The question this thesis raises is not whether or how we can make fair trade coffee but rather, how can we focus solutions to unjust trade relations to be politically effective for all involved?

Paleoecological analyses of an alkaline fen in the southern Interior Plateau of British Columbia, Canada were undertaken in association with ancient earth ovens. Local and regional vegetation and natural disturbance regimes were reconstructed using pollen, plant macrofossils and macroscopic charcoal. At White Rock Springs, Artemisia-Poaceae steppe occurred in the early Holocene and the inferred climate from this period was warmer and drier than present. Increasing moisture at 6000 14C yr BP fostered development of open Pinus ponderosa forests surrounding the fen, with Pinus contorta var. latifolia expanding at higher elevations. A slope-wash event likely resulting from root processing activities occurred in the late Holocene that resulted in 13% Asteraceae Tubuliflorae pollen at 2200 ± 80 14C yr BP. Macroscopic charcoal concentrations increased following this disturbance. Shortly after this time a modern open mixed conifer forest with Pseudotsuga menziesii was likely established. A second major ecological disturbance perhaps occurred within the last 200 years as indicated by fluctuating pollen values of P. ponderosa, Poaceae, Asteraceae Liguliflorae and wetland species. The fen’s vegetation history is consistent with regional records, but rapid changes during the late Holocene apparently occurred in response to disturbances. These disturbances are most likely linked to human root food harvesting and earth oven use, and later to ranching. Differentiation of P. ponderosa and P. contorta pollen types reveals intervals of local forest change that were not detected in previous studies. This study is part of a larger research project at Upper Hat Creek Valley including lithics, phytoliths, and patterns of earth oven structure. / Graduate

ABSTRACT PILOT SCALE WHEAT GERM STABILIZATION IN A SPOUTED BED OYMAK, Mert Mehmet M.S., Department of Chemical Engineering Supervisor: Prof. Dr. N. Suzan KINCAL Co-Supervisor: Dr. Cevdet &Ouml / ZTiN April 2006, 97 pages Wheat germ, a nutritionally rich by product of wheat milling, has poor storage stability due to its content of essential fatty acids along with oxidative enzymes. A pilot scale conventional spouted bed was designed and constructed as a high temperature &amp / #8211 / short time treatment unit to bring about drying and roasting effects. By facilitating the use of high temperature inlet air, yet maintaining the bed solids at a temperature below the degradation temperature, spouted bed dryers achieve thermal efficiencies unachievable by other dryers. The inlet diameter, diameter of the column and the angle of the cone were 6.2 cm, 16 cm and 65&deg / respectively. Thermocouples were placed on the inlet, exit and discharge gate of the column. Temperature profiles were recorded during drying, roasting and cooling of wheat germ. The drying temperatures ranged between 201 and 243&deg / C, operation times between 6.5 and 12 minutes, and air flow rate between 55 and 65 m3/h. It was seen that the degree of roasting was closely related to the exit temperature of the air. The exit air temperature range was determined as 155-160&deg / C. Sensory evaluation tests were carried out. Wheat germ processed at 60 m3/h &amp / #8211 / 209&deg / C for 12 min and 55 m3/h &amp / #8211 / 216&deg / C for 7 min were selected as the samples for storage studies, on the basis of the results of sensory evaluation tests. Reproducibility runs were carried out for the selected conditions. The bed height increase study was carried out at 60 m3/h &amp / #8211 / 240 to 243&deg / C. The processed and raw wheat germ was stored in paper pouches at 40&deg / C, to estimate the shelf life on the basis of earlier studies. Peroxide values of both raw and processed samples were followed during the storage period. The initial peroxide values of raw germ, processed samples, and reproducibility samples were 1.1 meq peroxide / kg oil. The peroxide value formation data were found to follow zero order rate kinetics. Comparison of the peroxide value changes in the processed and raw samples indicated that in the studied range of 55-60 m3/h &amp / #8211 / 209-216&deg / C &amp / #8211 / 7-12 min, about 8&amp / #8211 / 10 fold increase in the shelf life due to stabilization was achieved. The color parameters of each run were determined using the CIELAB (L*, a*, b*) system. Total color difference (&amp / #8710 / E*) values due to processing were calculated using L*, a* and b* values, to be between 2.3 and 58.6.

Mémoire (M.Eng.)-- Universite du Québec à Chicoutimi, 1992. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Eng.)--Université du Québec à Chicoutimi, 1996. / Document électronique également accessible en format PDF. CaQCU

O objetivo deste trabalho é a extração de Au, Ag, Cu e Zn a partir de dois tipos de lodos galvânicos utilizando um processo híbrido de sulfatação seletiva e lixiviação com tiossulfato de sódio e amônio. Nos experimentos realizados, o lodo galvânico foi misturado com um agente promotor de sulfato (enxofre, sulfato de ferro ou pirita) e foi tratado por processos pirometalúrgicos a temperaturas até 750◦C. Nesta fase, este agente sulfatante é oxidado térmicamente, transformando a atmosfera do forno e os óxidos metálicos em sulfatos solúveis em água. Depois disso, os sulfatos foram tratados por lixiviação com água para a recuperação de Ag, Cu, Ni e Zn. Como o ouro não forma sulfatos nesta reação, foi realizada uma segunda fase de lixiviação utilizando tiossulfato de sódio e de amônio, reagentes eficazes e menos prejudiciais ao ambiente do que o cianeto. Diferentes parâmetros foram analisados como qual agente promotor de sulfatação apresentou a maior recuperação de metais em solução, a proporção ótima lodo galvânico/ agente sulfatação, a temperatura de forno, o tempo de aquecimento no forno e o tempo de lixiviação. Além disso, uma comparação da recuperação de ouro com cianeto e tiossulfato de sódio e de amônio foi realizada. A configuração que demonstrou a melhor recuperação de metal em solução tinha uma proporção de 1: 0,4 de lodo galvânico/enxofre, uma temperatura de forno de 550◦C, um tempo de aquecimento de 90 minutos e um tempo de lixiviação em água de 15 minutos. Usando estes parâmetros, as taxas de recuperação de 75% de prata, 68% de cobre, 52% de Ni e 67% de Zn foram obtidas. A lixiviação de tiossulfato de sódio resultou em uma recuperação de 78% do Au, próximos aos valores obtidos utilizando cianeto. / The purpose of this work is the selective extraction of Au, Ag, Cu and Zn from two types of galvanic sludge using a mixed process of sulfate roasting and sodium thiosulfate and ammonium thiosulfate leaching. In the experiments, the sludge was mixed with a sulfate promoter (sulfur, iron sulfate or pyrite) and treated by pyrometallurgical processes at temperatures up to 750◦C. At this stage, this agent is thermally oxidized, turning the furnace atmosphere and the metallic oxides into water-soluble sulfates. Afterward, the sulfates can be treated by leaching with water for recovery of Ag, Cu, Ni and Zn. The gold does not form sulfates in this reaction and was recovered through a second leaching stage using sodium and ammonium thiosulfate, an effective reagent and less harmful to the environment than cyanide. Different parameters as the sulfate promoter that achieves the highest recovery of metals, the proportion of galvanic sludge to sulfating agent, the temperature, the heating time in the oven and the leaching time were evaluated. Additionally, a comparison of gold recovery using cyanide versus sodium and ammonium thiosulfate was performed. The configuration that showed the best metal recovery included a 1:0.4 ratio of sludge to sulfur, an oven temperature of 550◦C, a roasting time of 90 minutes and a water leaching time of 15 minutes. Using these parameters, recovery rates of 75 % of the silver, 68% of the copper, 52% of Ni and 67% of the Zn were obtained. The sodium thiosulfate leaching resulted in a recovery of 78% of the Au, close to the values obtained using cyanide.

Le calebassier (Crescentia alata) ou jicaro, est un arbre très important dans les systèmes agropastoraux des régions tropicales sèches d'Amérique. Ses fruits contiennent de nombreuses graines consommées traditionnellement, mais malgré son importance, peu d’informations existent sur ses propriétés nutritionnelles et son potentiel industriel.Dans un premier temps les caractéristiques physico-chimiques des graines, des cotylédons ainsi que des coques ont été analysées. Le cotylédon résulte contenir en moyenne 43% de protéines et 38 % de lipide (b.s.), ce qui est comparable à la plupart des graines d’oléagineux. La graine ne contient pas d’inhibiteur de trypsine, peu de phytates et pratiquement aucun sucre non digestible. Une analyse protéomique a révélé que les protéines sont principalement de faible poids moléculaire (~10 kDa), plutôt de type albumine 2S contenant comme le soja jusqu’à 16 % d’acides aminées essentiels. Parmi les lipides, 77.6 % sont des acides gras insaturés, en particulier l'acide oléique.S’agissant d’une graine consommée traditionnellement après torréfaction, cette opération unitaire a été étudié. Pour la première fois a été identifié par chromatographie en phase gazeuse olfactométrie (GC-O) un composé d’arôme caractéristique de la graine, l’éthyl-2-méthyl-butyrate dont la teneur augmente au cours de la torréfaction. Néanmoins, d’autres composés d’arôme tels que les pyrazines et certains aldéhydes contribuent aussi aux notes aromatiques spécifiques et agréables qui se révèlent après torréfaction. Cette opération thermique induit des changements physiques et micro-structurales dont la coalescence des globules gras observés par microscopie à balayage et le gonflement (puffing) qui est à l´origine de l’ouverture de la coque. Ce dernier changement a été exploité pour le décorticage de la graine afin de libérer le cotylédon blanc. Cette opération a été optimisée en fonction de la couleur et le nombre de graines ouvertes avec un modelage cinétique, obtenant un taux d’ouverture de plus de 90% avec une perte de luminance de moins de 10%. Après la torréfaction, un traitement de ré-humidification a été effectué pour durcir le cotylédon et obtenir une meilleure efficacité de décorticage.Les cotylédons ainsi libérés peuvent utilisés pour la fabrication d’un lait végétal qui présente des caractéristiques physico-chimiques, sensorielles et nutritionnelles supérieures à de nombreux laits végétaux présents sur le marché. Une analyse préliminaire a montré que le lait contient plus de 6% de lipides et 4% de protéines et maintient le couleur blanc des cotylédons et l’arôme caractéristique du jicaro. Des études cliniques ont aussi révélé que le lait obtenu a un indice glycémique bas (11). Cela vient confirmer son potentiel comme alternative bon pour la santé, s’agissant d’un lait sans lactose, sans facteurs anti-nutritionnels et avec un indice glycémique bas. / The calabash tree (Crescentia alata) or jicaro is a very important tree in the agro-pastoral systems of the dry tropical regions of America. Its fruits contain many seeds that have traditionally been consumed. However, despite its importance, little information exists on its nutritional properties and its industrial potential.In the first part of this work, the physicochemical characteristics of seeds, cotyledons and coats were analyzed. The cotyledon contains in average 43% protein and 38% lipid (d.b.), which is comparable to most oleaginous seeds. The seed contains no trypsin inhibitors, few phytates and almost no indigestible sugar. A proteomic analysis revealed that proteins are predominantly of low molecular weight (~ 10 kDa) mainly of albumin type 2S, comprising as soybeans up to 16% of essential amino acids. Among lipids, 77.6% are unsaturated fatty acids, mainly oleic acid.As it is a seed traditionally consumed after roasting, this unit operation was studied. For the first time, a volatile compound characteristic of its aroma, and whose content increases as a result of roasting, the ethyl-2-methylbutyrate, has been identified by gas chromatography-olfactometry (GC-O). Yet, other aroma compounds such as pyrazines and certain aldehydes also contribute to the specific and pleasant aromatic notes which are found after roasting. This thermal operation induces physical and microstructural changes, including the coalescence of fat globules, which was observed by scanning microscopy, and puffing which is at the origin of the opening of the seed coat.This last change has been exploited for the dehulling of the seed in order to isolate the white cotyledon. This operation was optimized regarding the color and the number of opened seeds with a kinetic modeling, obtaining an opening rate of more than 90% with a loss of luminance of less than 10%. After roasting, a tempering treatment was carried out to harden the cotyledon and obtain better dehulling efficiency.The isolated cotyledons can be used for the manufacture of a vegetable milk which has physicochemical, sensory and nutritional characteristics superior to many vegetable milks present on the market. A preliminary analysis showed that the milk contains more than 6% lipids and 4% protein and maintains the white color of the cotyledons and the characteristic aroma of jicaro. Clinical studies have also revealed that the obtained milk has a low glycemic index (11). This confirms its potential as a healthy alternative for a lactose-free milk with no anti-nutritional factors and a low glycemic index.

O objetivo deste trabalho é a extração de Au, Ag, Cu e Zn a partir de dois tipos de lodos galvânicos utilizando um processo híbrido de sulfatação seletiva e lixiviação com tiossulfato de sódio e amônio. Nos experimentos realizados, o lodo galvânico foi misturado com um agente promotor de sulfato (enxofre, sulfato de ferro ou pirita) e foi tratado por processos pirometalúrgicos a temperaturas até 750◦C. Nesta fase, este agente sulfatante é oxidado térmicamente, transformando a atmosfera do forno e os óxidos metálicos em sulfatos solúveis em água. Depois disso, os sulfatos foram tratados por lixiviação com água para a recuperação de Ag, Cu, Ni e Zn. Como o ouro não forma sulfatos nesta reação, foi realizada uma segunda fase de lixiviação utilizando tiossulfato de sódio e de amônio, reagentes eficazes e menos prejudiciais ao ambiente do que o cianeto. Diferentes parâmetros foram analisados como qual agente promotor de sulfatação apresentou a maior recuperação de metais em solução, a proporção ótima lodo galvânico/ agente sulfatação, a temperatura de forno, o tempo de aquecimento no forno e o tempo de lixiviação. Além disso, uma comparação da recuperação de ouro com cianeto e tiossulfato de sódio e de amônio foi realizada. A configuração que demonstrou a melhor recuperação de metal em solução tinha uma proporção de 1: 0,4 de lodo galvânico/enxofre, uma temperatura de forno de 550◦C, um tempo de aquecimento de 90 minutos e um tempo de lixiviação em água de 15 minutos. Usando estes parâmetros, as taxas de recuperação de 75% de prata, 68% de cobre, 52% de Ni e 67% de Zn foram obtidas. A lixiviação de tiossulfato de sódio resultou em uma recuperação de 78% do Au, próximos aos valores obtidos utilizando cianeto. / The purpose of this work is the selective extraction of Au, Ag, Cu and Zn from two types of galvanic sludge using a mixed process of sulfate roasting and sodium thiosulfate and ammonium thiosulfate leaching. In the experiments, the sludge was mixed with a sulfate promoter (sulfur, iron sulfate or pyrite) and treated by pyrometallurgical processes at temperatures up to 750◦C. At this stage, this agent is thermally oxidized, turning the furnace atmosphere and the metallic oxides into water-soluble sulfates. Afterward, the sulfates can be treated by leaching with water for recovery of Ag, Cu, Ni and Zn. The gold does not form sulfates in this reaction and was recovered through a second leaching stage using sodium and ammonium thiosulfate, an effective reagent and less harmful to the environment than cyanide. Different parameters as the sulfate promoter that achieves the highest recovery of metals, the proportion of galvanic sludge to sulfating agent, the temperature, the heating time in the oven and the leaching time were evaluated. Additionally, a comparison of gold recovery using cyanide versus sodium and ammonium thiosulfate was performed. The configuration that showed the best metal recovery included a 1:0.4 ratio of sludge to sulfur, an oven temperature of 550◦C, a roasting time of 90 minutes and a water leaching time of 15 minutes. Using these parameters, recovery rates of 75 % of the silver, 68% of the copper, 52% of Ni and 67% of the Zn were obtained. The sodium thiosulfate leaching resulted in a recovery of 78% of the Au, close to the values obtained using cyanide.