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By D. H. Stonehouse

Of the f ive Canadian cement producing regions- Atlantic, Quebec, Ontario, Prairie and Pacific-Ontario has the greatest capacity and normally produces the most cement. However, during the last 5 years the greatest activity within the industry in Canada has been in the Prairie and Pacific regions where major capacity increases have taken place. Most Canadian cement companies produce normal Portland, high-earlystrength Portland and sulphate resisting Portland cements. Some companies also manufacture moderate Portland cement, and low-heat-of-hydration Portland cement. Escalating energy costs highlight the need for technology research into more energy-efficient equipment for the energy-intensive cement industry. The industry is well integrated and plants are well situated to support construction in Canada. Expansion into the United States has become common during the past decade.

Jan 1, 1984

By Peter Clevenstine

Minnesota Iron Ore Trifecta 1. World Demand 2. Industry Consolidation 3. Competitive Advantages

May 1, 2011

By P. J. Sylvester, S. J. Piercey, S. Maloney, S. M. Brueckner, L. Pilgrim, D. Hyde, G. Ogilvie

The 1806 zone is part of a Au-rich volcanogenic massive sulfide deposit at the Rambler Camp on the Baie \/erte Peninsula, northwestern Newfoundland, and is characterized by high Au grades (3.97 g/t), relatively low Cu and Zn grades (0.60 wt% Cu, 1.17 wt% Zn), and moderate Ag grades (27.83 g/t) at ca. 0.37 Mt ore. Gold and Ag occur as electrum and different Ag varieties including Ag-Hg ± Au alloys, miargyrite, and pyrargyrite that occur often in close proximity to electrum. Additionally, Ag-, As-, Sb-, and Sn-bearing sulfosalts are frequently observed and usually close to electrum. These textural relations strongly favor a syngenetic/magmatic origin for the 1806 zone, despite having a metamorphic overprint.

Jan 1, 2011

By M. L. Jeremic, G. J. P Delaire

"The mechanical aspects of cable bolt failure are considered from the point of view of properties of grout and cable, as well as of the rock in which it is anchored. The results from recent investigations made in-situ as well as in the lab are combined and presented with reference to other work done in the area. An attempt is made to stimulate the thinking along these lines so as to initiate further research which may enhance the design of cable bolting as it applied to mining operations.IntroductionIn the past twelve year s systematic cable bolting has found application in many areas. In civil engineering rock anchors have been used to provide tension at the heel of a dam permitting the reduction of its cross section. They have been used in retaining walls to reduce construction time and costs by eliminating the need for struts and braces which complicate pouring the foundation walls. It is also possible to use rock anchors in providing reactions where tall buildings are subjected to uplift on one side due to wind forces. Cantilever bridges may be constructed by implementing rock anchors to provide anchorage requirements. Anchorage piles or dolphins or mooring ships have also been built using these. In the mining area rock anchors, commonly known as cable bolts because they are made of hoist cable may be implemented in the reinforcement of hanging walls or to retain rock slopes.In order to sustain de-pressurized ground where rock separation developed along the pressure arches, cable bolts were utilized at the Tsumeb Mine in South-West Africa and also at the Strathcona Mine in Sudbury, Ontario, In both places old degreased hoist ropes were installed in downholes from crosscuts above a given stope and then grouted without tensioning. Jeremic and Cassidy described the use of cable bolts to increase hanging wall stability and postpone fracturing, in addition to producing pre-support for improvement of stope back stability."

Jan 1, 1983

By M. Turner-Jones, N. Steenekamp

"The Lonmin Base Metal Refinery treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode as well as a concentrate containing the platinum group (PGM) metals. The original process employed a Sherritt design and utilizes atmospheric and pressure leaches for the dissolution of base metals. This paper describes the original flow sheet and the improvements made to enhance PGM recoveries, product quality and to increase capacity. Changes include the introduction of flash recycle cooling on the autoclave, batch leaches to improve the quality of the PGM concentrate and the implementation of solid-liquid separation with centrifuges. INTRODUCTIONThe Lonmin Base Metal Refinery (BMR) is about 100 km north-west of Johannesburg and treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode and a concentrate containing the PGMs. The plant was commissioned in 1985 based on a Sherritt design to treat 12 tonnes converter matte per day. The original flow sheet consists of a milling circuit, an atmospheric leach and a pressure leach to produce a PGM concentrate which is despatched by helicopter to the Lonmin Platinum refinery in Brakpan, about 40 km east of Johannesburg. The liquor from the atmospheric leach is treated by crystallization to produce a nickel sulphate hexa-hydrate crystal. The leach liquor from the pressure leach is treated by a selenium removal step followed by electro-winning to produce copper cathode. The spent solution from the copper electro-winning is recycled to both the atmospheric and pressure leach steps to provide sulphuric acid for the leaching reactions.Modifications were made to the original circuit to increase the plant capacity, to improve the PGM recoveries and to improve the quality of the PGM concentrate. Capacity increases included all the unit operations, new mill, new first stage, additional autoclaves, additional nickel sulphate crystallizers, new copper electro-winning and new batch leach reactors for upgrading the PGM concentrate. The current circuit is described in this paper and not the detailed history of each plant change."

Jan 1, 2012

By Daniel Lachapelle, Nuri Hmidi, Turgut Yalcin

"Simulation can serve as a convenient tool in studying the behaviour and performance of grinding circuits by facilitating the evaluation of various scenarios and identification of optimum operating conditions. This technique was applied to the St Andrew Goldfields Ltd.’s Stock Mine Mill which is a 1300 tpd gold milling facility, offering custom milling services as well as processing the Company’s own ores. Lack of adequate instrumentation in the mill poses a challenge in attaining optimum performance especially with changing ore types and characteristics. The grinding process is monitored essentially by manual measurement and adjustment of pulp densities at various streams. A simulation program was designed to assist in the effective implementation of this mode of grinding control. Product sizes from both the primary and secondary grinding circuits were correlated empirically to relevant process variables using a database formed from the results of past sampling campaigns. The simulator was created in Microsoft Excel whose data analysis and optimization tools coupled with its Visual Basic Programming capabilities were found to provide an excellent environment for the development of a cost-effective, efficient and user-friendly simulation program.INTRODUCTIONGrinding is often a very costly unit process in milling operations, mainly due to the excessive energy consumption associated with it. For example, for a Canadian copper-zinc flotation mill, grinding was listed as being the most costly item taking up 30.4% of the total milling expenses, followed by the flotation cost at 2 1 .O% (Kidd Creek Mines Ltd., 1982). A survey on 45 copper flotation mills around the world showed the average grinding cost to be 34.5% of the total milling cost (Weiss, 1985).Overgrinding aggravates the cost issue, while insufficient grinding either causes loss of valuable minerals to tails or results in low-grade concentrates. Therefore, it is essential that grinding circuits be carefully controlled and monitored. To this end, a great deal of effort has been devoted over the years to the modelling and simulation of grinding systems in order to assist in the efficient running of these processes."

Jan 1, 2001

By A. M. Martinez, L. Melis, R. C. Peláez, L. G. Garcia

Orovalle Minerals S. L. operates a copper/gold mine in the Asturias region of northern Spain, with the operation dating back to December 1997. The feed to the El Valle mill, consisting of oxide/sulphide (skarn) mineralization, is highly variable, even on a shift by shift basis and presents challenges to the mill operating staff on a daily basis. The mineralogical characteristics of the ore are quite complex with copper present as native copper and sulphides as well as copper minerals with deleterious elements. Gold is present as native gold and electrum. The mill circuit includes SAG/ball mill grinding, gravity recovery of native copper and gold, flotation of copper concentrate, carbon-in-leach gold recovery and SO2/air cyanide destruction. The paper will provide a description of the different unit operations and present operating data of the mill operation.

Jan 1, 2019

By R. L. Every, A. G. Fonseca

"Sulphur deposition on the internal wall of a pipeline is caused by the temperature effect on the solubility of sulphur in the carrier fluid and is not due to particulate sulphur present. Deposition can be completely eliminated by proper insulation of the pipeline to prevent ""cold-spots"" and the resultant temperature gradient necessary for sulphur to precipitate from solution. Friction head losses for sulphur-condensate slurry systems are quite acceptable from a technical and economic standpoint and, in fact, are less than many present commercial slurry systems. Slurry transportation of sulphur in a hydrocarbon pipeline is a viable possibility and promises to have economic advantage over currently accepted transportation modes."

Jan 1, 1972

By W. E. Roscoe

The probability of making an exploration discovery in Canada can be calculated from Derry's (1970) data on exploration expenditures and number of discoveries over the last nineteen years. Considering an average exploration "try" to be $30,000, the probability of a discovery with one try has decreased tenfold from about 0.01 in 1951 to 0.001 in 1969. A plot of these probabilities can be extrapolated to the future, giving a 1969-71 three-year average probability of 0.00096 with 90 per cent confidence limits of 0.00042 and 0.00153. Using this probability, various calculations can be made, such as (1) the probability of making at least one discovery for any given exploration expenditure, (2) the probability of ultimate ruin or survival of the exploration investment process and (3) the expected value of an exploration investment. There is a critical minimum amount per discovery that must be re-invested in exploration, no matter how large the original investment is, for exploration to survive at all in the long run. Currently, this critical minimum is $31,200,000 with 90 per cent confidence limits of $19,600,000 and $71,400,000.

Jan 1, 1971

The current mining operations at Newmont Boddington Gold Mine (NBG) commenced in 2008, and commissioning of the processing plant started in the latter half of 2009. Metso Process Technology and Innovation were engaged to assist NBG with commissioning and project ramp-up through the implementation of a comprehensive ?Mine-to-Mill? Process Integration and Optimisation project. This methodology entailed extensive data collection which included drill and blast audits, ore characterisation, comprehensive comminution circuit surveys and review of operational data to assess the limitations within the current mining and processing operations. The results of these investigations have been used to define the operating base line of both the mining and processing areas and identify improvement opportunities. The use of modelling and simulations, utilising actual production data, has allowed for multiple scenarios to be evaluated, minimising the requirement for actual trials and thereby minimising impact on the operation. Improvements implemented to date include: the introduction of routine rock strength measurement for inclusion in block models, modifications to blast design improving ROM fragmentation and downstream comminution process performance, and changes to improve performance of secondary crushing and grinding circuits. Close cooperation between the mine and plant personnel is playing a significant role in overcoming the challenges presented to this operation and further improvements are targeted for the second full year of process plant operation.

Jan 1, 2012

By Owsiacki. Leo

Both the 8 and A-C ore zones of the Heath Steele Mine contain extensive areas of brecciated ore. This texturally distinct ore type has been tentatively defined as a fragmental or conglomerate massive sulphide. It consists of subangular and round fragments of pyrite up to 30 em in diameter, smaller quartz clasts and chloritized, mineralized, lithic fragments in a faintly banded matrix of pyrrhotite and chalcopyrite. The chalcopyrite is concentrated in the pressure shadows of the fragments and appears to reflect remobilization and recrystallization during a deformation which postdates the formation of the clasts. A generally conformable relationship with the underlying banded pyrite-sphalerite ore, discordancy with the host banded argillites, spatial distribution and similarity to Kuroko ores suggest that the fragmental ore is of primary origin and that breccia formation is probably due to soft-sediment slumping or sliding initiated by volcanic explosions, as hypothesized for similar massive sulphides in various Japanese mines. It is nevertheless recognized that certain structural features in some clasts may result from deformation preceding the formation of the breccia, and at this stage a tectonic origin cannot be completely eliminated.

Jan 1, 1979

By T. Banerjee, Y. Dumais, R. Lemire

"Agnico Eagle LaRonde produces over 300,000 ounces of gold annually, along with silver, zinc and copper by-products. The LaRonde plant consists of a conventional SAG and Ball mill circuit, followed by flotation. Load management is imperative for maintaining stability in grind size and ensuring consistency of the flotation feed. In flotation, the mass pull profiles of the cells and reagent dosage rates need to be managed to maximize recovery, while maintaining product quality. This is achieved by controlling the air, level and reagent addition set-points across the circuit. However, disturbances such as feed size distribution, ore hardness and mineralogy make it challenging to maintain efficient control using traditional control techniques. LaRonde therefore worked to develop a progressive control strategy, targeting stability and optimization. This started with a year-long instrumentation upgrade campaign, focusing on optimizing the performance and reliability of plant-wide instrumentation. The process was then optimized, leveraging AwaRE advanced controllers running in closed loop with PARC modules embedded within the PLC. The installation of 8 PFC cameras in flotation changed the flotation operation from a level and air control based strategy, to one that controls mass pull. This new control philosophy has allowed the plant to effectively manage mill load, improving grind size and providing increased throughput with better flotation performance.INTRODUCTION Background Since 2015, Agnico Eagle LaRonde has been conducting an optimization campaign to maximise the performance of plant assets leveraging instrumentation and control. The grinding and copper flotation circuits were identified as the areas having the greatest opportunities and value proposition for advanced control. A disciplined approach was followed to design and implement a progressive control solution to achieve operational excellence."

Jan 1, 2018

The methods employed for the addition of uranium to steels and cast iron in the Physical Metallurgy Division are outlined. It has been found that the segregation of? uranium is a major problem in aluminum and/or silicon killed steels and that the cooling rate is important in al-lowing the segregate to settle to one area, which can subsequently be discarded. The unsegregated areas were found to be extremely low in total oxygen, acid insoluble aluminum (AizOg) and, in some cases, slightly lower in nitrogen. Uranium recoveries, based on analyses of the unsegregated areas, were quite constant, at about 45 per cent, regardless of the type of uranium master alloy used for the addition. No segregation of carbon, manganese, silicon, sulphur, phosphorous, chromium or copper was observed in these steels. In commercial heats, the recoveries ranged from 7 to? 29 per cent for ladle additions to oxygen converted steel. When the steel was fully deoxidized prior to the uranium addition, recoveries ranged from 49 to 66 per cent, regardless of the steelmaking process.

Jan 1, 1964

By Egon Berger

"In recent years the trend in underground metal mining has been toward ever increasing blasts (often in excess of 100 000 tonnes per blast). The Canadian mining industry has been in the forefront of these developments (VRM, LBHand cable bolting to stabilize the surrounding rock /avoid dilution).In order to move these large tonnages, efficient loading systems have to be developed. This paper shows the technical and economic implications of various loading scenarios based on a predefined (however typical) stoping layout by:1 . discontinuous loading using scoop trams;2. discontinuous loading using scoop trams in combination with low profile dump trucks;3. continuous loading (based on loading performance/operating costs of the AL-60) in combination with low profile dumptrucks.The cost advantages of production concentration (loading large tonnages from one drawpoint}, made possible by continuous loading as opposed to sea tiered mining (small tonnages), using discontinuous loading in tunnelling will be presented, based on actual results obtained in a decline development project using the A L-60 continuous loader. At as pacing oj150m between turning bays, it was found that continuous loading was out performing discontinuous loading in approximately80% of the overall decline development.Fuel consumption and total cycle times are compared, and a cost assessment is presented.INTRODUCTIONThe subject of this paper deals with the introduction of continuous loading in underground metal mining and single heading tunnelingContinous mining has been widely introduced both in underground and surface coal mining. Mechanized longwall mining, utilizing moveable shield supports in combination with double drum- shearers, has resulted in a tremendous increase of coal production per working face.This has led to very concentrated mining operations. In a typical German coal mine two mechanized longwalls nowadays would produce the same amount of coal as 12 to 15 longwalls in the 1950s. One longwall in a South African coal mine has recently set a world record with 120 000 tonnes of coal in a single month.In underground metal mines-often due to the irregular nature of the ore body and the mining methods used-mining is far less concent rated. Ore is often produced from a large number of stopes and production sections. Sometimes, a substantial amount of ore may be obtained from development in the orebody (40070 at a German base metal mine)."

Jan 1, 1989

"Conveyed coal flows have been diverted on the basis of real time ash analysis since the 1980s. Many coarse particle separation methods are available through screens, jigs, heavy media separation, particle sorters, to name a few, however bulk diversion requires a representative, continuous analysis to ensure diversion decisions can be made with confidence. Sensors also need to be able to provide measurements at useful time increments so that small tonnages can be diverted for maximum selectivity. Particle separation typically requires high capital costs and there are limitations either in throughput tonnage or particle size or both. Few techniques are able to provide robust and representative analysis of conveyed flows in a useful time basis. Prompt Gamma Neutron Activation Analysis provides multi-elemental analysis of conveyed bulk materials and has been proven in the minerals industry since 2003. This paper outlines the success of this technology in minerals applications in iron ore, phosphate rock and most recently in copper-gold ores, including its use in bulk diversion.INTRODUCTION Naturally occurring quality variability, or heterogeneity, in mineral deposits enables separation and recovery of the valuable components through mining and processing operations. There are distinct advantages in processing the minimum quantity of material to achieve the highest possible yield. Unfortunately, declining ore grades has resulted in larger scale operations and a subsequent loss in selectivity for mining operations. As limits are approached on the practical size of equipment, there is more motivation to investigate alternative solutions. Mining companies are subject to increasing social resistance to growing waste disposal requirements in addition to higher energy and transport costs. Major savings are available by reducing the quantities of material processed where pre-concentration can be effectively applied at early stages in the process. One of the simplest ways to pre-concentrate is to measure the bulk material and reject waste soon after mining so that minimal expense is incurred and that only higher quality material is sent to processing operations. This bulk sorting can occur within the mining operations and has major benefits through energy and other consumables savings. This paper discusses the application of real time analysis technologies suitable for bulk sorting within the minerals industry. Technology that has proven representative for conveyed material bulk analysis and its successful applications to date is explained. Analysis using a sensing technique is only one component of a successful bulk sorting process; the importance of effective diversion systems and a bulk sorting strategy are also discussed. The bulk sorting stage may be one component of a system that could include additional downstream technologies such as particle based sorting systems on a diverted stream."

Jan 1, 2018

By G. C. Mackenzie

At the last Annual Meeting of the Institute, Dr. C. V. Corless sketched the potential mineral wealth of Canada so clearly, graphically and with-all so entertainingly that one's imagination was fired with the promise held out to future generations for the tremendous expansion of the mining industry in the Dominion. Posterity will undoubtedly witness the fruit of much of the geographical search and survey that is now carried on by our government mining departments. Year after year the work advances, slowly but surely, new areas are . explored, older areas are surveyed in detail, the information being compiled in maps and reports of incalculable value to the prospector, the engineer and the general public. The immensity of the task of exploring, geologically, the outlying portions of the country, with the ultimate view of making valuable mineral discoveries, may be visualized from a study of Dr. Corless' paper and the subsequent discussion which took place and one becomes impressed with the fact that three-quarters or more of the problem can be included under the word "transportation". For instance Dr. Corless said, "The few geological explorers who have penetrated to these remoter regions . . . . . . have as a rule been compelled to stick closely to canoe routes,"; Dr. Goodwin remarked, "This barren Laurentian granite, which is put down on the maps as covering the greater part of this area, is the best guess the geologist could make from travelling along watercourses Within the next few years . . . . . . the Timiskaming and Northern Ontario railway will undoubtedly be extended to James Bay . . . . . . In order that we may be prepared for the probable influx of prospectors when transportation facilities to tidewater are provided, I think all available information on this district should be gathered together in handy form." All three-Corless, Goodwin and Cole-emphasize the well-known fact that explorers, geologists and prospectors working in new country must stick to the watercourses and that transportation by rail, road or water has always been the all-important deciding factor in facilitating the exploration and development of remote districts. Dr. Corless did, however, suggest other means of transportation in stating, "The aeroplane will be of assistance in future study of some parts of these remote areas."

Jan 1, 1924

By J. Peterson, D. D. Tannant, J. Todd

"A review of blast designs and improved blasting practices at the EkatiTM diamond mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine’s well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. EkatiTM uses 270 mm holes for production blasting, and 165 mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion/ANFO blends. The mine plan involves using 30 m double benches. A 30 m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15 m benches. This paper summarizes the monitoring equipment and data gathered to date. IntroductionThe EkatiTM diamond mine is located about 300 km northeast of Yellowknife, Northwest Territories, Canada. The mine is a joint venture of BHP Diamonds Inc. (80%) and geologists Charles Fipke and Stewart Blusson (10% each). The EkatiTM mine is Canada’s first diamond mine and BHP is the operator. The mine is accessed by air and by a winter ice road.The first kimberlite pipe mined at EkatiTM is known as the Panda pipe. The Panda open pit mine will have a total depth of 315 m (Fig. 1), a width of about 600 m, and a 50° overall slope. Initial ore production is 9000 tonnes per day.This paper summarizes the pre-strip blasting and the evolution of the production and wall control blast designs from 1997 to 2000. The initial blast designs and the rationale behind subsequent changes that took place are presented along with the techniques currently in use.The paper also briefly presents an experiment done to measure the rock mass response to blasting. Three blasts were instrumented with geophones, gas pressure sensors and time domain reflectometry cables. A brief summary of the instrumentation and data gathered is included."

Jan 1, 2001

By Tom Shumka

INTRODUCTION ?The Electro-Magnetic Crack Detection (EMCD) technique is an electromagnetic inspection method used for detecting and sizing surface breaking flaws. ?It works well on structural material or welds, ferrous or non-ferrous metals. ?EMCD?s rapid scanning is achieved using a hand-held probe. ?EMCD provides reliable crack detection and sizing (length and depth). Cracks can be sized accurately. ?EMCD dramatically reduces most cleaning requirements as there is no need to clean to bare metal. ?EMCD is capable of inspection through thin metallic coatings, or through non-conducting coatings up to 10mm thick. ?EMCD allows full data storage for back-up, off-line view and audit purposes.

Oct 1, 2010

By D. G. F. Hedley, F. Grant

"In 1958, the Ontario Department of Mines appointed a committee to study the accident situation and mining methods used in the uranium mines in the E1liot Lake district. This committee reviewed the existing knowledge on mine design, pillar support and roof spans and came to the conclusion that scientific knowledge had not yet reached the stage of producing rational design procedures which would reduce the dependence on trial-and-error methods. Since that time, the Mining Research Centre has made numerous stress measurements in two mines to define the pre-mining and pillar stresses. A comprehensive series of tests has been done in the laboratory to measure the compressive strength of the rock; a geological survey of the region has been made to evaluate tectonic stresses; and a survey was done on mining conditions with regard to stable and unstable pillar configurations. This information has been used to evaluate pillar design as effected by pillar width and height, depth below surface, extraction and pre-mining stress fields. The resultant design of pillar widths and corresponding extraction as the depth increased is in line with past and present experience in these mines. The information available on roof stability is still insufficient to design stable stope spans with the same degree of confidence; experience and trial-and-error methods are still required."

Jan 1, 1972

By M. Al-Khawaja, F. Hassani, F. Mucciardi, N. Razavinia

"In today’s economy many industries are becoming aware of the need to recover some of the waste heat they create. Industrial processes release, on a global scale, over 100 tera-Joules (i.e. 1014 J) of waste heat annually. The recovery of waste heat can lead to a reduction of greenhouse gas emissions and it can also provide a financial benefit which can be obtained by converting some of this excess heat to electricity. At McGill, a research program has been initiated so that low grade waste heat (temperature between 100ºC and 300oC) from process off-gases found in pyro-metallurgical industries is captured and concentrated by using heat pipes and then converted to electricity by a mechanical engine. This paper illustrates the 3 C’s process (capture, concentrate and convert waste heat to electricity). It also provides some preliminary experimental data. INTRODUCTIONThe problematic climate change caused by the use of fossil fuels, the rapid depletion of global reserves and the catastrophic consequences of nuclear power generation call for renewable and safe, resources of energy, for both man and the environment. Extensive researches in the production of energy from renewable sources and improvements in efficiency of current technologies can help us to reverse this trend.The greatest advantages of using renewable energies are that they don’t deplete and they also contribute to a green environment. On the other hand the disadvantage of using these resources is that the energy available from renewable sources is much less concentrated than that provided by fossil fuels and nuclear energy. This makes renewable energy less attractive for large scale industrial uses in most cases. A key target for society for the 21st century is the production of energy from renewable sources at a cost that is competitive with fossil fuels. Fossil fuels represent a concentrated form of energy; usually it is referred to as high grade energy. Nonetheless, there is a vast supply of alternative energy. The sun, wind, water and biomass were the first to be explored. While these are all valid options that warrant concerted efforts and large investments, there is another source of energy that typically is produced by manufacturing industries. This energy is often referred to as low grade waste heat. Most of this energy is simply vented to the environment through the stream of off-gases. In the future it will be necessary to capture and convert some of the low grade heat to a valuable form such as electricity if we are to improve on the efficiency of energy usage."

Jan 1, 2012