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By N. Kuyucak

"Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. It occurs as a result of natural oxidation of sulphide minerals contained in mining wastes at operating and closed/decommissioned mine sites. AMD may adversely impact the surface water and groundwater quality and land use due to its typical low pH, high acidity and elevated concentrations of metals and sulphate content. Once it develops at a mine, its control can be difficult and expensive. If generation of AMD cannot be prevented, it must be collected and treated. Treatment of AMD usually costs more than control of AMD and may be required for many years after mining activities have ceased. Therefore, application of appropriate control methods to the site at the early stage of the mining would be beneficial.Although prevention of AMD is the most desirable option, a cost-effective prevention method is not yet available. The most effective method of control is to minimize penetration of air and water through the waste pile using a cover, either wet (water) or dry (soil), which is placed over the waste pile. Despite their high cost, these covers cannot always completely stop the oxidation process and generation of AMD. Application of more than one option might be required.Early diagnosis of the problem, identification of appropriate prevention/control measures and implementation of these methods to the site would reduce the potential risk of AMD generation. AMD prevention/control measures broadly include use of covers, control of the source, migration of AMD, and treatment. This paper provides an overview of AMD prevention and control options applicable for developing, operating and decommissioned mines."

Jan 1, 2002

By Cz. Mora, A. Pawelczyk, D. Hreniak, P. Nowak, A. Dyonizy, S. Strek, W. Strek, K. Grabas, A. Ostrowski

Globalization and a growing demand for limited raw material resources have forced changes in the approach to the supply chain. This is particularly true in the case of rare earths, which are regarded as one of the most important development indicators of modern technologies. To ensure a secure supply of commodities, the European economies have been prompted to investigate REE recovery from sources which until recently, for technical or economic reasons, were considered not sufficiently attractive. An interesting example is apatite phosphogypsum waste dumps. The REE content in these waste dumps averages around 0.5-1 %. One of the most important phosphogypsum locations in Poland is the Lower Silesia region where a phosphoric acid Chemical Plant "Wizów" operated for several dozen years. In this work, rare earths are leached from the phosphogypsum crystalline structure by a chemical treatment and can then be separated into individual chemical compounds. The technology used in these recovery tests, matches up to a coherent European raw materials policy supporting effective management of resources and promoting waste materials recycling.

Jan 1, 2014

Located in Timmins, Ontario the Porcupine Joint Venture, a pooling of assets between two existing operations (the Dome Operation of Placer Dome (CLA) and the Hoyle Pond Operation of Kinross Gold Corporation) came about on July 1st, 2002; Placer being the manager of the Joint Venture with 51% ownership and Kinross with 49%. The formation of the Joint Venture was the realization of the dream of many who could envision the benefits of the whole area being operated as one entity ? the combination of the majority of assets in the Porcupine Camp into one venture containing tremendous synergistic potential of manpower, infrastructure, land tenure and exploration development. The name Porcupine in the gold mining industry brings with it the legacy of world class gold mines; the Hollinger, McIntyre and Dome with a proud tradition of excellence. The name Porcupine brings with it the legacy of over twenty individual mining companies in operation at any one time, producing over 65 million ounces of gold.

May 1, 2003

"The link between ore texture and mineral liberation has previously been established at a microscopic scale. To construct ore texture models that can be used in mining applications requires this relationship to be retained at a significantly larger scale. This is initially dealt with by finding a basic set of microtextures that form the elements of the ore textures at the next larger mesoscopic scale, simulating these mesotextures at a fine scale, then changing the support of the mesotexture simulations to generate the expected mining block/stope mesotexture distributions. Thus, a mutually exclusive and exhaustive set of spatially locatable mesotextures can be used to fully characterize the metallurgical properties of in situ material.A method that generates expected distributions of mesotextures for any mining block size or shape is proposed, and includes: (1) characterizing the spatial correlation of the set of mesotextures with a single covariance function; (2) generating multiple simulations of mesotextures at a fine scale; and (3) using the simulations at a fine scale to generate the expected mining block/stope mesotexture distributions. A case study, using the George Fisher sediment-hosted base metal deposit in Queensland Queensland, Australia, is developed to demonstrate the proposed methodology as well as show the inadequacy of off-the-shelf approaches.Mining-scale texture models can be used to improve the in situ discrimination of ore from waste by exploiting the joint spatial variability of grades and textures to quantify the expected metal recovery of in situ material, then calculate local marginal cut-off grades. An artificial case study is presented to demonstrate the changes in ore/waste selection when considering ore texture models compared to constant metal recoveries."

Jan 1, 2005

By Joel T. Werner

Tire costs represent one of the highest controllable costs in open-pit mining, accounting for approximately 10% of mining costs. Tire monitoring technology has evolved rapidly in recent years and is emerging as a viable tool for extending tire life and reducing costs. The majority of the major tire manufacturers and several independent companies are in various stages of developing monitoring systems that capture and store vital tire data. Previously this information had only been accessible when the vehicle passed a fixed point in the mine, or when mine personnel manually downloaded the data. Integrating this technology with a mine management system enables remote collection and management of trend and alarm data. Mine personnel can now monitor a tire?s health parameters at any time, anywhere on site, regardless of the vehicle?s location. Anomalous tire conditions can be detected early and corrective actions taken. This information can then be integrated with other major onboard systems, operating conditions, and geographical information. Tire monitoring no longer exists as a stand-alone technology, but has evolved into an important integrated tool for mine operators. This paper will review the current status and benefits of integrating this emerging technology with a real-time mine management system.

May 1, 2002

Many mines in Canada, the US and S. Africa are reaching the hoisting limit. Very little payload will be possible without compromising safety due the excessive weight. It has been suggested (DeLorme, 2000), that one of the most attractive concepts to enable deeper hoisting is to reduce the allowable factor of safety in the wire rope. Researchers at the Spokane Research Lab are developing new technology to improve hoisting safety and productivity by providing new monitoring and analytical tools. A Shaft Conveyance Monitoring System (SCMS) has been developed which determines hoist rope end load, true conveyance position and acceleration, and rope safety factor, as well as other hoist operating parameters. This information is transmitted to the hoist operator display 20 times per second. Recent field measurements on 45 mm(1 ¾ in.) diameter hoist rope indicate that dynamic forces during loading of a 9000 kg(10 ton) skip may exceed the safety factor of the rope. To improve on the current understanding of the mechanical behavior of hoist ropes, and to help interpret the results from field-testing of the SCMS, a new approach to computer modeling of stranded wire rope is also being developed. Particle Flow Code, PFC3D (Itasca 1995b) is used to simulate the structural behavior of wire rope and the interaction between individual strands when the rope is subjected to static and dynamic end loading. Details of the SCMS, field results from the measured rope loads, and the results of numerical modeling on the wire rope will be discussed.

May 1, 2002

By Frederick W. Breaks, Andrew G. Tindle, Julie B. Selway

"Abstract - Rare-element pegmatites may host several economic commodities, such as tantalum (Taoxide minerals), tin (cassiterite), lithium (ceramic-grade spodumene and petalite), and cesium (pollucite). Key geological features that are common to pegmatites in the Superior province of Ontario and Manitoba, Canada, and in other large tantalum deposits worldwide, can be used in exploration.An exploration project for rare-element pegmatites should begin with an examination of a regional geology map. Rare-element pegmatites occur along large regional-scale faults in greenschist and amphibolite facies metamorphic terranes. They are typically hosted by mafic metavolcanic or metasedimentary rocks, and are located near peraluminous granite plutons (A/CNK > 1.0). Once a peraluminous granite pluton has been identified, then the next step is to determine if the pluton is barren or fertile. Fertile granites have elevated rare element contents, Mg/Li ratio < 10, and Nb/Ta ratio < 8. They commonly contain blocky K-feldspar and green muscovite. Key fractionation indicators can be plotted on a map of the fertile granite pluton to determine the fractionation direction: presence of tourmaline, beryl, and ferrocolumbite; Mn content in garnet; Rb content in bulk K-feldspar; and Mg/Li and Nb/Ta ratios in bulk granite samples. Pegmatite dikes with the most economic potential for Li-Cs-Ta deposits occur the greatest distance (up to 10 km) from the parent granite.Metasomatized host rocks are an indication of a nearby rare-element pegmatite. Metasomatic aureoles can be identified by their geochemistry: elevated Li, Rb, Cs, B, and F contents; and by their mineralogy: presence of tourmaline, (Rb, Cs)-enriched biotite, holmquistite, muscovite, and rarely garnet.Once a pegmatite dike has been located, the next step is to assess its potential to contain Ta mineralization. Pegmatites with the highest degree of fractionation (and thus the most economic potential for Li-Cs-Ta) contain blocky K-feldspar with >3,000 ppm Rb, K/Rb < 30, and >100 ppm Cs; and coarsegrained green muscovite with >2,000 ppm Li, >10,000 ppm Rb, >500 ppm Cs, and >65 ppm Ta. Pegmatites with Ta mineralization usually contain Li-rich minerals (e.g., spodumene, petalite, lepidolite, elbaite, amblygonite, and lithiophilite) and may contain Cs-rich minerals (e.g., pollucite, Cs-rich beryl). The ore minerals of Ta are commonly manganotantalite, manganocolumbite, wodginite, and microlite; Ta-rich cassiterite is also commonly present. Tantalum mineralization tends to occur in albitic aplite, mica-rich (lepidolite, cleavelandite ± lepidolite), and spodumene/petalite pegmatite zones."

Jan 1, 2005

By K. Najim, D. Hodouin

"The raw ores which are processed in mineral processing plants exhibit very strong variations of their physical and chemical properties. As a consequence, the performances of the comminution and separation processes vary greatly from time to time. Model-based control strategies improve the performance of the plant; however, they require some form of adaptation to cope with the variations of the are properties.This paper deals with the use of adaptive techniques for the control of mineral processes. It begins with a survey on adaptive control algorithms including parameters estimation aspects. Then several examples dealing with crushing, rod, ball, autogenous and semi-autogenous grinding, flotation , drying and calcination processes are reviewed.IntroductionThe operation of the various processes of mineral processing plants (crushing, grinding, flotation, dewatering, etc.) is generally controlled using empirically tuned regulators of constant structure, such as PID controllers. To improve the operation performance, mineral processors try to implement specifically designed controllers, i.e. controllers based on plant dynamic models. Most of the time, these techniques improve the control of the mineral processing installations. However, modelling is a complex procedure because of the problems of measurement and data management, specific to this industry, and because of the variations of the model parameters. In this context model-based control strategies do not always bring the expected improvements or are sometimes discarded and replaced by more conventional techniques .The sources of variation of the dynamic behaviour of mineral processing systems can be classified into three categories: (I) the inherent changes of the raw ore properties (composition, grindability, mineralogical texture, etc.); (2) the process tuning modifications (grinding media loads, number of hydrocyclones, slurry level in flotation cells, agitation speeds, etc.); (3) the feedrate variation of the ore, water, chemical reagents, etc. All these factors change the fundamental properties of the process dynamics such as the grinding or flotation rates and the residence time in the equipment. The simplified linear models which are used to describe the process dynamics are not able to track the complex behaviour of the mineral processing systems when the amplitude of the sources of variation are too large. The mismatch between the model and the plant behaviour is then frequently a cause of model-based controller failures."

Jan 1, 1992

By Chuck Edwards

"The development of two large, high-grade uranium projects has been proposed for northern Saskatchewan. The projects are now under review by a joint federal/provincial panel. The McArthur River project is owned by the McArthur River joint venture (Cameco Corporation 53.991 %, Uranerz Exploration and Mining Limited 29.775%, Cogema Resources Inc. 16.234%) and operated by Cameco. Cameco proposes to mill the McArthur River ore at the existing Key Lake mill. The Cigar Lake project is owned by the Cigar Lake joint venture (Cameco Corporation 48.75%, Cogema Resources Inc. 36.375%, Idemitsu Uranium Exploration Canada Ltd. 12.875%, Korea Electric Power Corporation 2.000%). The Cigar Lake joint venture proposes that Cameco operate the Cigar Lake mine for the owners, and that Cogema mill the ore at their McClean Lake mill, now under construction. Proposed systems provide safe mining and ore handling, and allow the milling of McArthur River ore at Key Lake and Cigar Lake ore at McClean Lake. This avoids the disturbance of new sites for milling and tailings disposal.The McArthur River and Cigar Lake deposits are the largest known high-grade uranium deposits in the world. The ore grades at McArthur River and Cigar Lake are at least 100 times those that are mined elsewhere. It is proposed to mine these deposits using remote underground mining methods, to crush and grind the ore underground, to pump a thickened ore slurry to surface, and to transport it in special containers by truck to the mills.During all mining and processing stages the ore is fully contained. Radon emission is controlled by positive ventilation of all process vessels, with the process ventilation backed up by the primary mine ventilation system. Radiation is controlled by heavy steel pipe and vessel walls, concrete walls and sometimes lead sheeting."

Jan 1, 1997

By E. M. Watkin

"Although Canada has achieved one of the highest living standards in the world, people and organizations have, over the past decade, begun to question the cost and means of this achievement. Concern has been expressed about the degree of environmental disturbance arising from industrial activities which have greatly contributed to our increased living standards. These industries include hardrock mining, pit and quarry operations, hydro-electric schemes, various agricultural enterprises and urban land developments.In the construction and operation of the above industries many environmental problems arise because the natural vegetative land cover is destroyed or drastically disturbed. Disturbance may occur to such a degree that revegetation is di ffi cult, often it appears impossible. Portions of the environment around such industries remain aesthetically unacceptable and appear to offer little or no potential for future resource use in wildlife, recreation or agriculture.The general public cannot dissociate itself from the activities of the aforementioned industries. It has, over many years, accepted the benefits and conveniences arising from those activities. Despite this, the increasing level of public concern imposes upon industry a need to alleviate or repair past, present and future environmental disturbance. Therefore it is incumbent upon industry to modify present technology or develop new techniques which would allow the disturbed environment to be easily and rapidly repaired."

Jan 1, 1975

By B. Y. Park

This paper develops a series of three-dimensional simulations for the Bayou Choctaw Strategic Petroleum Reserve. The U.S. Department of Energy plans to leach two new caverns and convert of one of the existing caverns within the Bayou Choctaw salt dome to expand its petroleum reserve storage capacity. An existing finite element mesh from previous analyses is modified by adding two caverns and increasing the size of existing Cavern 102. The structural integrity of the three expansion caverns and the interaction between all the caverns in the dome are investigated. The impacts of the expansion on underground creep closure, surface subsidence, infrastructure stability, and well integrity are quantified. The results show that from a structural viewpoint, the locations of the two newly proposed expansion caverns are acceptable, and all three expansion caverns can be safely constructed and operated.

May 1, 2009

By R. Sharon, P. M. Hawley, X. Ochoa

"Development of Barrick Gold’s Pierina gold mine in north-central Peru requires construction of a waste dump for disposal of nonore grade materials stripped from the open pit to expose the ore. The waste dump site is located near the open pit in a U-shaped valley that is underlain by thin colluvial and morainal soils with locally thick peats and glaciolacustrine deposits. Bedrock underlying the site consists of variably weathered volcanics. The site is subject to moderately high seasonal rainfall and significant seismicity. The geotechnical quality of the waste rock is highly variable, ranging from low-quality, degradable, soil-like materials containing appreciable quantities of silt and clay, to high-quality, hard, durable, blocky waste rock.A hybrid dump design concept was developed that requires in-pit segregation of highand low-quality waste, and selective placement of materials in the dump to maximize stability and enhance internal and subsurface drainage. The design includes a rock drain beneath the dump along the axis of the valley and a series of connected finger drains. Extensive peripheral diversions and stormwater control measures to inhibit infiltration of precipitation are also included.This paper discusses the unique challenges presented by the site and waste materials, the design methodology and stability analyses, and planned monitoring systems."

Jan 1, 2003

"This paper reviews the chemistry involved in the recovery of gold from cyanide solution with anion-exchange resins, and also discusses the most critical aspects of the engineering of an effective resin-in-pulp (RIP) process. As far as the chemistry is concerned, the conclusions reached by a great many researchers, as well as the performance of the only operating RIP plant in the Western World, at the Golden Jubilee Mine in South Africa, support the view that the process is technically viable and, in many cases, could prove to be more attractive economically than alternative processes such as zinc cementation and carbon-in-pulp (CIP). On the engineering side, there is still a need for further development before larger scale ( > 50,000 tpm) RIP plants can be designed, built and operated with confidence. However, the experiences gained during nearly 3 years of operation of the Golden Jublee RIP plant indicate that the process can be engineered with confidence for smaller operations ( < 50,000 tpm), and this will probably be the scope of application of the first-generation RIP plants. INTRODUCTIONThe use of anion-exchange resins in gold processing has, for a number of years, been proposed as an alternative to more conventional processes such as zinc cementation and carbon adsorption, and detailed research programs that have been carried out at a number of laboratories have demonstrated the technical viability of the process. (Burstall et al, 1953, Davison et al., 1960, Tataru, 1973, Laskorin et al. 1978, Hosking, 1984, Riveros and Cooper, 1987 and Palmer et al., 1988)The main incentive for this work was the fact that resins have several characteristics that are quite different from carbon, which make them potentially more attractive substrates for the recovery of gold. The following are examples: -"

Jan 1, 1991

By Harry Siewert

"The commissioning of the 4th concentrator (C4) at Freeport Indonesia in early 1998 increased total mill throughput from 130k to 230k tonnes per day. The C4 flowsheet consists of a single 38 ft diameter SAG mill, four 24 ft diameter ball mills followed by four banks of 4,500 ft3 WEMCO flotation cells.The design of the C4 rougher flotation circuit was based on the expectation that the copper and gold recoveries achieved with the 4500 ft3 flotation cells would be equivalent to or better than that achieved with the 3,000 ft3 flotation cells in the 3rd concentrator (C3) rougher circuit. This assumption was due to the fact that the C4 flotation feed size would be less than 15% +212 microns compared to the C3 rougher flotation feed size of less than 23% +212 microns. By mid 1998 it had become apparent that the C4 rougher flotation copper and gold recoveries were below those predicted.In order to determine the cause of the lower recoveries, stage by stage rougher flotation surveys were performed in all four concentrators. The results of the surveys showed that the C4 rougher flotation circuit had a lower recovery of +200 micron material than that achieved in the C 1, C2 and C3 concentrators. Through mineralogical analysis, it was determined that a majority of the copper contained in the +200 micron fractions was liberated and recoverable. This paper describes the steps taken to increase coarse particle recovery, overall plant recovery and the results achieved."

Jan 1, 2001

By Bradford C. Wesstrom, Ricardo Parra

The Freeport McMoRan El Paso Refinery uses co-generation to produce some of its electricity and all of its steam. This paper will cover the operation of the co-generation plant natural gas turbine at a fixed RPM for blade longevity and energy output. The by-product heat from the turbine passes through boilers with additional heat from a duct burner to produce steam for the Tank House and auxiliary operations. The steam demand varies dramatically throughout the day based on unloading activities in the Tank House. The use of an automated steam control system within the El Paso Refinery will help stabilize line pressure by incrementally controlling steam consumption based on electrolyte temperature. This will minimize steam line pressure fluctuations. INTRODUCTION In the mid 1920’s the Nichols Copper Company of Laurel Hill, New York recognized the need for a modern copper refining facility in the southwest. Due to the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the logical location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Energy costs (electrical and thermal) are critically important in the viability of modern copper electrorefineries. The El Paso Refinery produces electricity and steam through its cogeneration system. The El Paso cogeneration facility is a natural gas, 15-megawatt facility containing five turbine generators and associated waste heat recovery boilers. The facility is divided into two phases. Phase I consists of two Allison 2.2-megawatt turbine generators. Phase II consists of three Solar Taurus 3.5-megawatt turbine generators. Presently three units in Phase II are operated. The Phase I units were purchased and installed in 1986 and the Phase II units in 1992 (Solar 1991). The facility operated at full capacity until 2003 when steam demand was significantly reduced due to decrease in cathode production and closure of the copper sulfate and precious metal operations. Phase I units were taken out of service and put on care and maintenance status.

Jan 1, 2019

By A. H. Marquis

Since the start-up of its first Direct Reduction Module in April 1973, S1DBEC has produced over 2 million tons of prereduced iron. During this period, SIDBEC has acquired comprehensive experience in the operation of the direct reduction process and at the same time has learned to recognize the characteristics that the oxide should have to constitute an adequate feed for the process. A comparison is made as to the design and operation of the two direct reduction units now operating at Contrecoeur, Que. A description is given of a method of evaluation of a direct reduction unit, which takes into account the main process variable sand which permits comparison ofthe results on a daily basis. The paper defines the characteristics that the iron oxide and the prereduced iron pellets must have to meet the specific requirements of the direct reduction and the electric arc furnace processes. A simple model makes possible a rapid evaluation of the technical and economic effect related to the use of a given raw material. Finally, the paper outlines the advantages of prereduced iron in the steelmaking process and on the quality of the steel products.

Jan 1, 1979

By Steve Custer, Tim Kahl, Sue Parker

"The primary objective of the Barrick Goldstrike expert system is to achieve the desired liberation size for the autoclave circuit while maximizing throughput. In addition, when downstream limitations (autoclave circuit or others) restrict the milling circuit tonnage the expert system further improves grinding product size. Since its implementation, the expert system has provided expected throughput improvements while improving or maintaining circuit performance.Barrick Goldstrike and MinnovEX Technologies Inc. teamed up to install an expert system to control Line I and I1 of the autoclave grinding circuits. The dissimilar equipments of the two grinding circuits coupled to different production objectives, skepticism among operators, and the variability of the ore types processed in each line challenged the implementation.To ensure implementation success, Barrick Goldstrike dedicated four administrators full time to the project. The system administrators included two metallurgists, a process control engineer and a mill trainer. As usual, the control room operators were the experts who provided the operational logic for the foundation of the control system. The administrators and all eleven of the control room operators signed off on acceptance of the system. Current online utilization is 95%.INTRODUCTIONThe grinding circuit for Barrick Goldstrike’s autoclave process consists of two SAG Mill Ball Mill lines. Line 1 grinding circuit is comprised of a 22 by 8 foot, 2500 horsepower Allis Chalmers (AC) variable speed SAG mill, followed by a 12.5 by 14 foot, 1250 horsepower AC ball mill, and a 13.5 by 18 foot, 1800 horsepower Dominion ball mill in parallel. SAG mill recycle from the primary discharge screen (+5/16 inch) is processed through a 1352 Nordberg Omnicone crusher (4.5 foot). A secondary SAG discharge screen (+1/8 inch) closes the SAG circuit. The ball mill circuit is closed with 6 Krebs super D20 cyclones. Line 2 grinding circuit is comprised of a 24 by 12 foot 4000 horsepower Fuller variable speed SAG mill followed by a 16.5 by 30.5 foot 5000 horsepower Fuller ball mill. SAG mill recycle from the primary discharge screen (+5/16 inch) is processed through a 1560 Nordberg Omnicone crusher (5 foot). A secondary SAG discharge screen (+1/8 inch) closes the SAG circuit. The line 2 ball mill circuit is closed with 12 Krebs super D20 cyclones. The underground Meikle ore is typically fed through Line 1. Achieving the desired product size is critical for successful processing of Meikle ore. Open pit Betze ore is fed to Line 1 when Meikle ore is unavailable. Line 2 processes Betze ore exclusively. Throughput is maximized when processing Betze ore as the product size is less critical. The products of these two circuits are combined as feed to the autoclave circuit. The ore types and the autoclave circuit demands determine the required grinding circuit product size and maximum combined mill feed tonnage."

Jan 1, 2001

By D. L. Cluff

Ventilation Air Methane (VAM) is a high volume low concentration methane source. The capture or use of methane from VAM is challenging, which results in the routine discharge of methane into the atmosphere. Mitigating VAM has the benefits of providing an energy source and reducing the atmospheric Greenhouse Gas (GHG) burden. The GHG radiative forcing effect of methane is 17?23 times as potent as carbon dioxide on a 100-year time horizon. Thus, any reduction in atmospheric methane would be beneficial. The calorific value of methane is 55.5 MJ/Kg; therefore, a 100 m3/s flow with VAM concentrations from 0.1?1% can provide 3.8?38 MW of exploitable power. Strategies to mitigate VAM such as: Thermal Flow Reverse Reactors (TFRR), Catalytic Flow Reverse Reactors (CFRR), Lean Burn and Catalytic Gas Turbines, Biothermica Vamox®, Megtec VOCSIDIZER©, and Vamcat? are briefly reviewed. The review of VAM mitigation technologies reveals disadvantages such as the need to maintain a minimum internal heat capable of oxidizing the methane. This requirement uses all of the available methane up to the point of reaction sustainability and up to half at the highest methane concentration in VAM. Some systems may introduce a pressure drop to the ventilation system, which would impinge on the existing ventilation system design. These impediments necessitate the development of a more amenable technology. In the proposed system, gas turbines (GT), coupled to a combustion chamber with an external fuel supply, assist the combustion of the VAM. The combustion-chamber coupled system provides electricity, while the heat contained in the GT exhaust gases increases the temperature of the VAM, encouraging the development of a flame inside a combustion chamber. The flow from the combustion chamber streams through a primary air/fluid heat exchanger capable of producing steam of a high enough quality to generate electricity using conventional steam turbines. The residual heat after primary extraction, directed through other equipment, provides additional heat based products such as industrial scale dry air, chilling by an absorption chiller or hot water. The overall design of the system is scalable for low to high VAM flows or variations in concentrations and is capable of providing the company or community with heating, chilling, hot water, electricity or motive force as needed by the particular site or community. The Multi-generation system uses heat from three sources to provide clean efficient energy while mitigating the atmospheric emissions of methane. These sources are heat from the GT, often considered waste heat, heat from fuel injected into the igniters and heat from the VAM. The opportunity to collect carbon credits may improve the economics. In order to design a system with this capacity, a detailed analysis of the combustion characteristics of three separate flows is required. VAM is the main airflow, having the highest volumetric effect, while the GT exhaust and the additional fuel added to the hot exhaust flow of the gas turbine are lower flows, but have a higher velocity and temperature. The aim of the modeling undertaken in this work is to establish the combustion dynamics, degree of pre-heating required and the geometry essential to the design of combustion based VAM mitigation multi-generation systems.

Aug 1, 2013

By Karl J. C. Harries

"7.1. INTRODUCTIONThis chapter addresses the joint venture and examines a number of general concepts of the joint venture relationship. Chapter 8 looks at some specific concepts related to the provisions of a joint venture agreement, which are equally applicable to a shareholders’ agreement or other contractual relationship. The term “joint venture” is used because the author is a common law solicitor (a matter of convenience for which apologies are offered to civil law readers), but it should be noted that, in many aspects, the legal structure of an entity is irrelevant. It is the relationship of the parties, be they venturers or shareholders, that is important, and the areas of concern are surprisingly similar (except for terminology).The details of the joint venture relationship and agreement could fill several books. Accordingly, this chapter and the next focus on selected topics that appear to have caused problems or confusion or to be the basis for disputes. And remember that, although the following discussion is in the context of a joint venture, many of the comments apply, either directly or indirectly, to virtually any common undertaking and the agreement defining it.For interest’s sake, this chapter starts with a summary of some of the earlier types of agreements and arrangements that have evolved into the joint venture agreement of today in Canada, the philosophy of their format, and the reasons for their demise.7.2. EVOLUTION OF THE CANADIAN JOINT VENTUREThe Early DaysMuch of the opening up of Canada’s north is due to exploration for and development of mines. The early discoverers were relatively free to roam and explore at will and, if they were fortunate enough to find something, they dealt with the appropriate government to acquire exploitation rights. The early interests lay in gold or silver. Workings were small, usually worked by the owner alone or with only a couple of helpers to extract the native gold or silver. If the owner wanted to move on, he could sell his property outright and use his stake to look elsewhere.As logging and mining camps were opened, the development of better roads and railways made access easier. Entrepreneurs saw the opportunity to make money by assembling large parcels of land and working them as a single operation. In order to do this, some owners who were not ready to sell out had to be convinced to do so through more attractive offers"

Jan 1, 2003

By N. W. Kirshenbaum

"The Marconaflo slurry system was originally developed to reduce costs and solve technical problems in the marine transport of mineral cargoes. In the short time since its inception, it has been found to offer economies and advantages for land-based and in-plant materials handling. This efficient method of reclaiming and slurrying particulate materials at very high pulp densities can be directly utilized in a wide variety of mineral process systems. These include: storage-reclaim applications, where even cohesive, compacted materials can be reclaimed from settled storage ""on demand""; the growing number of hydrometallurgical operations wherein slurried materials are processed to extract or yield metals; certain applications associated with pyrometallurgical treatment; and as a means of augmenting the performance of conventional mineral dressing equipment, such as thickeners.INTRODUCTIONIn the continuing effort to lower costs of producing minerals and extracting metals, the field of handling and transportation often receives too little attention from those engaged in the mining and winning of ores and metals. This comment, which pertains to ferrous and non-ferrous as well as to non-metallic producers, is especially pertinent to products having relatively low value, where transport costs can be a major portion of the delivered selling price to the minerals receiver.One method which was developed recently for the purpose of reducing costs and solving technical problems in marine transport and handling of mineral cargoes is the MARCONAFLO slurry system. A notable feature of this system is its versatility; in addition to its use in marine transport1*, some of its diverse applications have included the mining and reclaiming of tailings2 and in-plant materials handling3. As the concept and fundamentals of this system have been well explained previously4,5, the mechanics of the system will not be elaborated upon here. Rather some specific ways in which MARCONAFLO can be applied to processing and extraction will be explored."

Jan 1, 1973