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By R. S. Douglas

Introduction The operations of The Granby Consolidated Mining, Smelting and Power Company, L1mited, have always been concerned with the mining of low-grade copper ores. In the fifty years of this Company's existence, nearly 60,000,000 tons of such material has been successfully mined and treated. During these years, many changes in mining practice took place. However, at Copper Mountain, due to the large tonnages of very low grade material, it was realized that something more than changing mining methods would have to take place if these low-grade orebodies were to be mined at a profit and the Company and. its employees enjoy many years of successful operation and employment. Production costs were mounting commensurately with rising taxes and the increasing cost of supplies, labour, freight, and smelting, while the value of the product on the market was not increasing in price to compensate for the higher costs of production. A survey of the mineable ore in 1944 indicated that, of the 12,000,000 tons in the reserves, only 3,500,000 tons was now profitable ore. This reduction in the commercial ore reserves was a serious matter, as it meant that the mine had only two years of life at the profitable shipp1ng rate of 4,800 tons per day. Further, the location in the mine of the orebodies making up the 3,500,000 tons was not suitable for such high production.

Jan 1, 1950

By J-P. Rossetti, A. Guerin, M. Jaboyedoff, L. Baillet, A. Mariscal, J. D'Amato, D. Hantz

"The processes leading to the fall of rock compartments from rock walls are poorly known as well as their velocity. It ensues that quantitative prediction of the failure time for a rock compartment which is presently stable, is not possible by a purely geomechanical approach. However a quantitative probabilistic prediction of rockfalls at the scale of a rock wall is possible if the spatial-temporal rockfall frequency can be determined or estimated (Hantz, 2011). For a better knowledge of failure processes and frequency, rockfalls have been detected in several rock walls, using annual terrestrial laser scanning, allowing comparison of the frequencies in different geological conditions. For one of these rock walls, the spatial detection have been completed by a precise dating of the events, using a quasi-continuous photographic survey (one photo every 10 mn), allowing the study of the influence of meteorological factors.The precise dating of rockfalls has been carried out for the Saint-Eynard cliff which towers above a residential area of the town of Grenoble (French Alps). The South-East facing cliff consists in bedded limestone gently dipping North-West and located at an elevation between 850 m and 1100 m. The surveyed zone is about 750 m large and 250 m high. Between 01/02/2013 and 26/11/2013, 65 rockfalls ranging between 0.01 m3 and 20 m3, have been detected by diachronic comparison of laser scanner data and dated by comparison of photographic images. The temperature at the elevation of the cliff has been calculated from the temperature measured (every 5 mn) at a meteorological station located at an elevation of 245 m and 2.5 km away from the cliff, using a temperature gradient of 0.003°C/m (D’Amato et al., 2014). The precipitation were measured 900 m away from the cliff at an elevation of 469 m. Different meteorological conditions have been defined: (a) “freeze” qualifies days with negative mean temperature (but with a thaw period, except for two days); (b) “thaw” qualifies days with positive mean temperature, but following a freeze day; (c) “rain” qualifies days with precipitation.Table 1 shows the rockfall temporal frequency for the different meteorological conditions. It appears that the frequency is about 6 times higher the freeze days, 2.5 higher the thaw days and 3 times higher the rain days than days without freeze, thaw or rain."

Jan 1, 2015

By D. C. Treilhard

After a brief history of the mining and smelting operations of Kilembe Mines Limited, this paper outlines the smelter layout and describes . the. daily operations at the Jinja plant. Particular attention 1s paid to the details of the furnace and converter operation. A subsequent section of the paper deals with the significant developments in plant metallurgical practice, covering both smelting and converting.

Jan 1, 1966

By Pingchao Ke, Zhihong Liu

"To overcome the problem that scoroditeis not stable in neutral and alkaline solutions, we proposed and investigated a synthesis method of scorodite coated in-situ with hydrated ferric oxide in the Fe(II)-As(V)-H2O system at the initial Fe(III)/As(V) molar ratios larger than 1.0.The synthesis was carried out at 90?,pH 1.5 under atmospheric pressure. During the synthesis, oxygen gas was conducted and bubbled into the system to oxidize Fe(II) ions into Fe(III)ions, and Na2CO3aqueous solution as neutralizing agent was added controllably into the system for keeping the pH constant at 1.5. In this study, three samples of scorodite were synthesized at the controlled initial Fe(II)/As(V) molar ratios of 1.0, 2.0 and 3.0, respectively. The characterizations of the samples by HRTEM, TEM/EDX, and chemical composition indicated that the particle surfaces of scorodite synthesized at the initial Fe(II)/As(V) molar ratio of 2.0 and 3.0 were coated in situ by a film of hydrated ferric oxide with the thickness of several nanometers, while the sample synthesized at the initial Fe(II)/As(V) molar ratio of 1.0 was uncoated scorodite. The TCLP and long-term leaching for the toxicity characteristic of the samples showed that scorodite coated in situ with hydrated ferric oxide was stable in a wide pH range from 3.0 to 10.0, with the arsenic concentrations in the leaching solutions less than 1.0mg/L. Nevertheless, uncoated scorodite was unstable under the conditions from weak acidity to alkalinity, with the arsenic concentrations in the leaching solutions larger than 5.0 mg/L.INTRODUCTIONArsenic pollution is a challenge for environment and health and has been an important issue for scientists (Hopkin, 1989).Arsenicis commonly associated with ores or concentrates of nonferrous metals, mainly as independent arsenic bearing minerals such as arsenopyrite (FeAsS), tennantite(Cu12As4S13), enargite (Cu3AsS4), cobaltite (CoAsS), and gersdorffite (NiAsS), realgar (As2S2), orpiment(As2S3), etc.(Matschullat, 2000; Mandal & Suzuki, 2002; Long & Peng, 2012). In the nonferrous metallurgical processes, arsenic is enriched mainly in such arsenic bearing materials as various flue dusts, residues, and anode slimes, which results in the accumulation of arsenic in the system owing to the circulation of those arsenic-bearing materials back to the system and the pollution to the environment (Harris, et al, 2003).In addition, the utilization of arsenic is limited and has been decreasing owing to its toxicity and carcinogenicity. Therefore, arsenic has to be removed from those arsenic-bearing materials and discarded safely (Dutrizac & Jambor, 1988; Monhemius & Swash, 1999; Drahota & Fillippi, 2009).In this case, how to immobilize arsenic has become a difficult problem which must be solved. Among the methods of immobilizing arsenic which have been proposed and investigated, immobilizing arsenic into a stable mineral to fix it, has been realized as a promising method and becomes a research focus(Dutrizac et al, 1987; Dutrizac & Jambor, 1988; Demopoulos et al, 1995; Fujita et al, 2008a; 2008b).Scorodite has been known as one of the best minerals for immobilizing arsenic, owing to its high stability under weak acidic condition, the arsenic content as high as 32wt%,and good crystallinity benefiting the separation of solid to liquid(Daivid et al, 1999; Zhu & Merkel, 2001). Scorodite can be synthesized from arsenic containing solutions under both hydrothermal and atmospheric conditions, and a lot of work has been done on the synthesis of scorodite and its leaching stability characterization (Filippou & Demopoulos, 1999; Gomez et al, 2011).Two plants for the immobilization of arsenic as scorodite have been putin to operation in Chile and Japan, respectively (Filippou & Demopoulos, 1999; Amir et al, 2016)."

Jan 1, 2017

By M. Yavuz

As a branch of Operations Research, decision making is a widely used application in both science and social sciences. There are many different methods developed to solve decision making problems in the literature. In this study, Fuzzy Analytic Hierarchy Process (AHP) method is performed for the selection of reclamation project selection in an open pit mine and the optimal solution of the problem is investigated. Different reclamation project alternatives are prepared for an open pit mine, which continues to its production activities in magnesite sector in Turkey. The data obtained from Magnesite Cooperation is used in the application of the method. A decision-making process is prepared as considering the project alternatives for the purpose of selecting the most suitable reclamation project. The entire criteria that affect the decision-making process are identified and transformed into a hierarchical structure. The problem is solved by using Fuzzy AHP method developed according to this structure. It is found that Fuzzy AHP is a method that may help decision-makers in solving different decision-making problems in mining.

Aug 1, 2013

By M. W. Bates, A. L. Mular

This paper, based on work carried out at Queen's University, describes the development and use of mathematical models of the parallel cyclone classifiers being used in the Strathcona mill of Falconbridge Nickel Min.es Ltd.

Jan 1, 1971

By Ben Burger

This paper describes the design, the first three years of operation and optimization of a large, single stage SAG mill at Minera Yanacocha?s Gold Mill facility located in northern Peru. The Gold Mill was commissioned in March 2008 with a 32? x 32? EGL, 16.5MW single stage SAG mill, to process 5 million tonnes per annum high grade oxide Au/Ag ore. Operational control, feed size distribution, grinding media, mill liner, grate and pulp lifter optimisation have allowed the mill to operate 15-30% above design throughput rates, but with a product P80 coarser than design. As part of the optimization, full grinding circuit surveys were conducted. Historical operating data and survey data were analyzed and used to evaluate possible circuit changes and determine alternative operating strategies. A number of changes were implemented which allowed the SAG mill to operate similarly to a large ball mill and achieve finer mill product that was closer to design. This paper summarizes life to date data analysis and improvements made by Minera Yanacocha as well as the grinding circuit optimisation study conducted by Metso Process Technology and Innovation.

Jan 1, 2012

By K. U. Kainer

Magnesium and its alloys as the lightest available construction metal offer a wide range of opportunities for the usage in transportation industries, especially Magnesium wrought alloys with their improved mechanical properties show a high potential for structural applications, While magnesium cast components have found their application the interest is now spreading to wrought alloys due to the possibility to get even more homogeneous and better properties compared to cast parts, Therefore alloy and process development especially for extruded and sheet material is a main concern to enhance the application of Magnesium wrought alloys, Castings are still form the majority of applications of magnesium alloys, although efforts to develop adequate wrought alloys have increased, In the presentation, the alloy requirements for processing of cast and wrought alloys will be discussed, The various processing routes and alloy compositions result in specific microstructures and properties which determine the potential use of these alloys, Today, the spectrum of available alloys covers standard alloys as well as alloys for use at elevated temperatures, The trend will be to further diversify the alloy compositions and to improve the alloy properties, Areas of concern still remain the wrought processing and the high temperature (creep) and corrosion properties of magnesium alloys, Examples of recent developments in these sectors will be given, The presentation will also provide an overview of the historical and current use of magnesium and an outlook on future applications.

Jan 1, 2006

By P. O. Parfitt

At the McIntyre mine, there are two distinct operations: a gold mine with narrow veins, mined by cut-and-fill methods, and a copper mine with large, open, long-hole stopes. The application of the Critical Path Method to scheduling work in the copper mine, where it has been used successfully for several years, is de-scribed briefly. This application is relatively simple. Use of C.P.M. has now been extended to the gold mine. To replace the former method of scheduling from bar-charts, a procedure was developed for scheduling automatically. To handle an operation of this size and complexity, a computer was essential. Improved schedules are now being produced, with a saving in time.

Jan 1, 1967

By H. J. Oterdoom

SMS Group (SMSG) has always been concerned about safety aspects of electric smelter plants for the ferro-alloy and non-ferrous industry. The awareness for safety increased significantly over the past decades and also SMSG contributed with its design features to a safer operation. Today, safety aspects are not only part of the smelter design but also of the overall plant layout. Explosions in electric smelters are rare, but have a huge impact on peoples’ lives, on equipment and on production. For this reason, SMSG wanted to have a better overview of explosions within the smelting industry in order to see if useful statistics could be extracted. Generally, there is a lack of statistics regarding explosions in the electric smelting industry, and not enough information is collected or published. A significant portion of the explosions seems to be water related. Many companies, both operating and engineering, are trying to handle the risks of water, and apply methods to detect water leakages. Installing such a system is a management decision and management has then to make sure the system is properly implemented. The disadvantages and limitations of these systems should be carefully considered and communicated to operators and authorities.

Jan 1, 2015

By Julie Hunt

Rimfire Minerals Corporation: early stage precious metal exploration specialists with discovery opportunities in partnership with major and mid-tier gold producers or prominent junior exploration firms. Mike Roberts, Senior Geologist

May 1, 2006

By H. A. Oaks

FROM 1921 to 1939, the aeroplane played an increasingly important role in Canadian prospecting and mine development. This service has been interrupted by the war, but undoubtedly it will be accelerated in the postwar years, if suitable aircraft are available. The purpose of this paper will be to review the uses to which the aeroplane has been put in prospecting and development in the past, and its future possibilities as an aid in prospecting. If by review, and deduction, we get a clear picture of what we expect the prospecting plane to do, we may be able to arrive at a very close approximation of its required characteristics and, from this, an idea of costs. 'Function' is defined as the mode of action by which it (the aeroplane) fulfills its purpose. We will endeavour, therefore, first to find what this purpose is, or should be, so that our expectations will not be too limited nor too great-and then find, by analysis, what performance we require in an aeroplane to meet our reasonable expectations at an economic price.

Jan 1, 1945

By B. Konda, R. Lauer, D. Camilucci, D. Gladwin

"Income based taxes are significant cost elements to be considered in evaluating investment in new mine development. This paper presents the results of comparative analysis of effective income-based tax rates for mining in the Northwest Territories (NWT), selected Canadian provinces and international jurisdictions. The study was done as background to a review of royalty regulations for the NWT. ObjectiveThis paper presents results of comparative analysis of effective mining royalty1 rates, and combined effective mining royalty and income tax rates on selected mine models for the Northwest Territories (NWT), with those for several other jurisdictions in Canada and abroad which compete with the NWT for mining investment.BackgroundThe February 27, 1995 federal budget directed the Department of Indian Affairs and Northern Development (DIAND) to proceed with a comprehensive review and amendments to northern natural resource management legislation in order “to increase revenues and ensure a fair return to the Crown.” DIAND is responsible for the administration of the Territorial Lands Act, and its regulations.The Territorial Lands Act gives the Governor-in-Council the authority to “… make regulations for the leasing of mining rights in, under or on territorial lands and the payment of royalties therefor,…”. In the NWT, the Canada Mining Regulations (CMR) provide for the disposition of mineral rights for most minerals, other than coal, petroleum and related hydrocarbons, in return for the payment of a royalty to the Crown.As part of this review of the NWT mining royalty regime, several computer mine models were developed and tax regimes in a number of jurisdictions were analyzed. Effective mining royalty rates, and the combined effective mining royalty and income tax rates were compared across the jurisdictions. The results presented in this paper are a part of the background work done in preparing a discussion paper on proposed changes to the NWT mining royalty that is expected to be released for public consultation in the very near future."

Jan 1, 1997

By Jean-Marc Lulin

"Depuis 1906, pres de 130 gisements ont ere decouverts dans la inture archeenne polymetallique (Cu, Zn, Au, Ag) du nord-ouest becois. Une etude regionale du developpement du potentiel inier est presentee puis detaillee pour quatre secteurs: RouynDranda, Val d'Or-Malartic, Bousquet-Cadillac et Matagami.L' analyse est conduite a l' aide des parametres suivants: temps, ethodes de decouverte, profondeur des gisements et poids metal. ~~ courbes cumulatives illustrant le nombre de gisements decouverts fonction du temps montrent une forme generale en ""S"" dont les i'iations de pentes correspondent aux variations dans les taux de ~ouverte. Initiation, realisation et stabilisation des cycles de decourte sont ainsi mis en evidence. Deux ""bourns miniers"", de 1922 a ~5 et de 1955 a 1965, rassemblent 72 % des mines identijiees squ' a present.La plupart des mines sont trouvees en subsurface: 90% ont leur fmet entre 0 et 100 metres de profondeur dont 70 % entre 0 et 10 etres. Dans le temps, il y ad' abord recolte par prospection puis par fphysique et enjin, developpement progressif du potentiel en proeur avec des methodes composites. Environ 80% du poids metal extrait de 4 camps miniers, couvrant 8% de Ia surface regionale quelques gros gisements dominent /a production.Ces donnees permettent de proposer une nouvelle approche pour lysed' une region miniere:La distribution de Ia profondeur des gisements en fonction du temps est indicatricede /amaturite d' uncampminieret peut servir a evaluer son potentiel residue/.L' analyse des courbes en ""S"" permet d' extrapoler les taux de succes relies aux differentes methodes et met en relief le role crucial de I' innovation dans I' exploration.ABSTRACTSince 1906, some 130 deposits have been discovered in the Archean polymetallic belt of northwestern Quebec. In this paper, the development of the mining potential is analyzed at the regional scale and for the following mining camps: Rouyn-Noranda, Val d'OrMalartic, Bousquet-Cadillac and Matagami.The analysis is based on the following parameters: time, discovery method, depth and weight of metal extracted. Curves showing the cumulative number of deposits discovered as a function of time are ""S"" shaped with slope variations corresponding to changing discovery rates. Initiation, realization and stabilization of discovery cycles are thus well represented. Two ""mining booms"", 1922 to 1945 and 1955 to 1965, account for 72% of the mines identified to date.Most exploitable orebodies have been found near the surface: 90 %have their top between 0 and 100 meters, including 70% between 0 and 10 meters. Early discoveries were made by prospecting, followed by geophysics while the progressive development of the depth potential is being realized by a combination of methods. Approximately 80 %of the metal extracted comes from four mining camps which cover 8% of the area, but most of the production can be allributed to only a few large deposits. Based on these data, a new approach to the analysis of a mining region is proposed:1) The distribution showing deposit depth versus time is indicative of the maturity of a mining camp and can serve to evaluate its remaining potential.2) The ""S"" curve analysis can be used to extrapolate the success rate of a specific exploration method and also stresses the crucial role of innovation in exploration."

Jan 1, 1990

By Jean-Marc Lulin

"Depuis 1906, près de 130 gisements ont été découverts dans la inture archéenne polymétallique (Cu, Zn, Au, Ag) du nord-ouest québécois. Une étude régionale du développement du potentiel inier est présentée puis détaillée pour quatre secteurs: Rouyn-Dranda, Val d'Or-Malartic, Bousquet-Cadillac et Matagami.L' analyse est conduite a l' aide des paramètres suivants: temps, méthodes de découverte, profondeur des gisements et poids métal. Les courbes cumulatives illustrant le nombre de gisements découverts fonction du temps montrent une forme générale en ""S"" dont les i'iations de pentes correspondent aux variations dans les taux de couverte. Initiation, réalisation et stabilisation des cycles de décourté sont ainsi mis en évidence. Deux ""bourns miniers"", de 1922 à 1945 et de 1955 à 1965, rassemblent 72 % des mines identifiées sqú à présent.La plupart des mines sont trouvées en subsurface: 90% ont leur mmet entre 0 et 100 mètres de profondeur dont 70 % entre 0 et 10 êtres. Dans le temps, il y a d' abord récolte par prospection puis par ophysique et enfin, développement progressif du potentiel en proeur avec des méthodes composites. Environ 80% du poids métal extrait de 4 camps miniers, couvrant 8% de Ia surface régionale quelques gros gisements dominent /a production.Ces données permettent de proposer une nouvelle approche pour analyse d' une région minière:La distribution de Ia profondeur des gisements en fonction du temps est indicatrice de la maturité d' un camp minier et peut servir a évaluer son potentiel résiduel.L’analyse des courbes en ""S"" permet d’extrapoler les taux de succès relies aux différentes méthodes et met en relief le rôle crucial de I' innovation dans I' exploration.ABSTRACTSince 1906, some 130 deposits have been discovered in the Archean polymetallic belt of northwestern Quebec. In this paper, the development of the mining potential is analyzed at the regional scale and for the following mining camps: Rouyn-Noranda, Val d'OrMalartic, Bousquet-Cadillac and Matagami.The analysis is based on the following parameters: time, discovery method, depth and weight of metal extracted. Curves showing the cumulative number of deposits discovered as a function of time are ""S"" shaped with slope variations corresponding to changing discovery rates. Initiation, realization and stabilization of discovery cycles are thus well represented. Two ""mining booms"", 1922 to 1945 and 1955 to 1965, account for 72% of the mines identified to date.Most exploitable orebodies have been found near the surface: 90 %have their top between 0 and 100 meters, including 70% between 0 and 10 meters. Early discoveries were made by prospecting, followed by geophysics while the progressive development of the depth potential is being realized by a combination of methods. Approximately 80 %of the metal extracted comes from four mining camps which cover 8% of the area, but most of the production can be allributed to only a few large deposits. Based on these data, a new approach to the analysis of a mining region is proposed:1) The distribution showing deposit depth versus time is indicative of the maturity of a mining camp and can serve to evaluate its remaining potential.2) The ""S"" curve analysis can be used to extrapolate the success rate of a specific exploration method and also stresses the crucial role of innovation in exploration."

Jan 1, 1989

By H. J. McQueen

Mineral and energy resource consumption were continuously reduced by process improvements as chemical understanding was developed and applied. During the past two centuries, technological improvements increased human productivity that was accompanied by social advances and labour saving products; however, these sometimes proliferated to endanger sustainability, e.g., automobiles. In the steel industry, precisely controlled rolling of HSLA steels required little extra mineral consumption but reduced weight and heat-treating energy. Continuous casting of slabs reduced scrap compared to ingots and energy for the homogenizing soaking pit. Al alloy extrusions were improved by retaining the strengthening in the near-surface substructure, of high strength textures and of press quenching that is suitable for direct age hardening. Continuous bar casting of Al-0.65Fe, coupled with rod rolling and followed by wire drawing with only a final recovery anneal, yielded electrical wiring for households to replace less plentiful Cu and later for light-weighting use in autos and aircraft Looking backwards, the 1970 decade saw the first oil crisis and inspired Ottawa to undertake a campaign to develop an energy strategy that would decrease dependence on imported fuels. One significant undertaking under Energy Mines and Resources was the organization of industrial energy conservation, managed by each industry association,that collected detailed current statistics and set the goals for a 2-year campaign. The metal producing industries, as compared by E.C.N. Perryman to about 7.2 exajoules (EJ) for the nation, consumed about 0.8 EJ, being about one third of all heavy industries. While manufacturing consumed 30.2% of total energy, it created 87.3% of total national dollar value. Within the industrial envelope, smelting and refining utilized 28% (0.67 EJ, mining beneficiation 6.7%, 0.16 EJ); there was a significant contribution to exports: 80% of iron ore and 70% of aluminium in 1973. A general concern was that decreases in ore grade would lead to a rise in energy expenditures countering benefits from processing efficiency.

Jan 1, 2012

By E. J. Debicki

"At the 1992 PDAC Convention, Norman Keevil announced the formation of the Exploration Technology Division (ETD) of the Mining Industry Technology Council of Canada (MITEC). It was evident that base metal reserves in Canada were declining and that the cost of discovering a deposit in Canada was increasing. Coordinated research to develop new exploration technologies was required to discover the next generation of ore-bodies. The ETD was formed in response.The mission of the ETD is to contribute to the survival, profit, and growth of the Canadian mining industry by improving the efficiency and effectiveness of mineral exploration through development of innovative technology by man-aging and coordinating applied cooperative research. In addition, it is the intent of the ETD to become the principal agency by which cooperative research funds are transferred to researchers from the mining industry. The division is industry driven, industry funded and industry managed.The ETD’s Three-Year Plan has focussed80% of its research funds toward two objectives, improving the efficiency of exploration for VMS deposits and establishing the parameters necessary to discover the next Hemlo deposit. The remaining 20% is allocated to other projects, with the current emphasis on geophysics.In 1995, corporate members total twenty-three major mining companies accounting for90% of the exploration expenditures in Canada. The ETD is currently managing ten cooperative research projects totalling $4.6million. Other projects, estimated at $1.6 mil-lion, are currently under development."

Jan 1, 1996

By G. S. Hume

"THERE HAS BEEN a marked growth in the petroleum industry in Canada since the end of the war. The rate of growth in the demand for oil products has exceeded that in United States, although the per capita consumption is still less. Estimates of the consumption of petroleum and petroleum products in Canada in 1951 are approximately 154,000,000 barrels, which is slightly more than 11 •barrels per capita, whereas the estimated consumption in United States for the same period, according to World Petroleum, is placed at 2,619,- 970,000 barrels. This, on the basis of a population of 154,000,000, would be equivalent to 17 barrels per capita. The increase in consumption of the petroleum and products is world wide. World production in 1951 has been estimated (Oil and Gas Journal) at 11,700,000 barrels a day or more than 41;4, billion barrels for the year. United States production increased 13.7 per cent to 6,143,000 •barrels a day and Canada'.s ,, total production increased about 65 per cent from a total of 29,091,235 •barrels in 1950 to an estimated (Dominion Bureau of Statistics) 48,096,800 barrels in 1951.The trend to use increased amounts of petroleum and petroleum products, particularly in the United States and Canada, has also been supplemented by increased use of natural gas. The rate of expansion of the consumption of natural gas in United States in the past few years has been very rapid, increasing from 2,600 billion cubic feet in 1940 to 5,975 billion in 1950, with the proven reserves in the same period increasing from 85,000 billion to 186,000 billion cubic feet."

Jan 1, 1952

By A. Danaei, A. McLean, M. Barati, C. Ravindran

"The aluminum industry generates about 90 million tonnes of red mud each year. Previous research shows it could be utilized as a refining flux with a high capacity to absorb phosphorus and sulphur from hot metal in the steel industry. The present study was undertaken to evaluate the melting properties of such fluxes, as it affects the effectiveness of the flux. The results show that the melting behavior of red mud is strongly affected by lime addition and the characteristic melting/softening temperatures reach minimum VALUES (at 32.7 wt% CaO. From these findings, a correlation was established between melting behavior and optical basicity. This allows one to adjust the composition of the flux based on the process requirements. INTRODUCTIONThe aluminum industry generates about 90 million tonnes of bauxite residues each year. This residue is usually red in color because it contains a substantial amount of iron oxide. The red mud, as it is called, is a solid waste with a high concentration of sodium oxide, high pH (10 to 13), and high alkalinity, and thus is harmful to many forms of life. Traditionally, the material is stored in large tailings ponds within the plant’s vicinity (Power, Grafe, & Klauber, 2009). Development of solutions for safe disposal or preferably using this residue for other industrial processes or applications could help restore polluted locations and eliminate a negative impact on the environment (Haake, 1988; Power et al., 2009; Yan & Xuegong, 2010).The mineralogy and chemical composition of red mud depends on the quality of the bauxite and refining process parameters. In general, it consists of iron oxide (Fe2O3), aluminum oxide (Al2O3), titanium oxide (TiO2), sodium oxide (Na2O), silicon oxide (SiO2), and calcium oxide (CaO) (Power et al., 2009). Like most ores and soils, bauxite can contain trace quantities of metals such as arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and naturally-occurring radioactive materials, such as thorium and uranium. Most of these trace elements stay in the residue (Power et al., 2009)."

Jan 1, 2012

By William G. Pariseau

"This contribution describes linkage of stress concentration at the face of tabular excavations, for example, longwall coal mine panels, at a meter scale to surface subsidence at a kilometer scale. Joints are considered according to orientation and spacing at an intermediate scale. A new dual-node, dual-mesh technique based on first principles uses a multi-scale technique that allows for computing whole mine surface subsidence while also allowing for computational details of stress, strain and displacement about main entries and pillars, panel entries, and bleeder entries. The technique is implemented in a conventional continuous Galerkin finite element program that has been in use for many years.The advantage of the dual-node, dual-mesh technique is the capability to do a whole mine analysis that takes into account interaction between all sections of a mine where stress transfer over long distances is often the rule rather than the exception while at the same time allowing for details of stress concentration at working faces where caving is initiated and subsidence begins. The technique, outlined recently during ARMA 2014 (Pariseau, 2014), is applied to an underground coal mine in central Utah where mines are developed from outcrops in steep canyon walls. Meshes contain over 10 million, three-dimensional nodes; runtimes are typically overnight, as a practical matter. Results compare favorably with mine subsidence measurements made over a period of several years and show the capability of this new technique to provide useful design guidance for tabular deposits such as underground coal mines. The role of variability or uncertainty in strata properties is illustrated in element safety factor distributions about development, bleeder and main entries and pillars. Such details are new in this contribution. Energy tracking for mine-induced seismicity is also new. Results show a high correlation between number of events and failed elements and suggest a simple index to mine induced seismicity."

Jan 1, 2015