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By Jacques Deraisme

The technology of percussion drilling is well mastered. The lower cost of percussion drilling allows more holes to be drilled for the same budget. However significant differences are often observed between percussion and diamond drill assay data. This is due to the increased level of contamination associated with the percussion drilling process. Statistical studies on twinned drillholes show that diamond and percussion assays cannot simply be merged in a traditional kriging approach. The question then arises on how to use both types of data to produce reliable resource estimates. To take into account the lower reliability of the percussion assays, a noise characterized by a variance is added to these data. The methodology consists of two steps: 1. Cokriging of the equivalent diamond value at the percussion assay locations. 2. Block kriging using diamond assays and equivalent diamond values, calculated previously, adding to these data a noise, whose variance is the cokriging variance of step 1. This particular way of achieving kriging is called kriging with variance of measurement error. The paper illustrates this innovative methodology with an application on an iron deposit. The results of this method is compared to block kriging using only diamond assays and the gain in precision is quantified. An extension of that approach to multi-element cokriging is also presented.

Oct 1, 2009

By I. C. Brown

Introduction Many tables of nomenclature for igneous rocks have been introduced from time to time, and each has its strong proponents. As a result, any discussion of igneous? rocks is apt to prove confusing unless the names used for these rocks are defined. This ?became so obvious to a discussion group, formed by the members of the Geological Survey of Canada in 1948, that an attempt was made to establish a scheme of nomenclature that could be used by any member mapping anywhere in Canada. The writer was asked to co-ordinate the ideas presented by individuals in the discussion group, to arrange them in tabular form, and, later, to distribute copies of the resultant table to Canadian universities, provincial geological surveys, and some other geological discussion groups. Many useful suggestions and criticisms were received, were studied ?by members? of the original group, and, so far as practicable, were incorporated in the scheme of nomenclature. The result is the table presented here. This nomenclature of igneous rocks is at present being used by most members of the Geological Survey of Canada who are working with igneous rocks, and by some Canadian universities. We hope it will be found useful and be more widely accepted. With this idea in mind, certain principles were adopted in drawing up the nomenclature.

Jan 1, 1952

By M. C. Bétournay

Under the requirement to define the economic advantages of using hydrogen fuel cell vehicles, a broad-scoped project was initiated to quantify the costs associated with operating fuel cell vehicles and diesel vehicles. While ventilation savings are clearly an advantage for the former, a complete and detailed analysis of this and other operational and capital cost elements was undertaken in order to provide the mining industry with factual information in considering the changeover from one technology to another. This paper outlines the results of the investigations to date defining the costs/benefits associated with capital purchases, operations (electrical/diesel, mine air heating fuel, ventilation, openings, surface and underground infrastructure, maintenance, labour, etc.), delivery of energy, regulatory obligations, and mine production. Considerations are given to the type and size of a mining operation, the depth, and location in North America. Significant ventilation power, equipment, and infrastructure savings are possible with the application of fuel cells for shallower mine applications. At depth, where heat is an issue, there is a reduction in benefit. Specific qualifiers such as minimum air velocities, dust dilution, shaft, and heating system velocity limits must be considered on an individual mine basis. While the capital cost for fuel cell mining equipment is currently higher than diesel versions, the high cost of fuel cells is anticipated to be reduced significantly in the near future with the intensification of manufacturing. In either case, the operational savings would probably be sufficient to balance the supplementary capitalization costs. Comprehensive reports have been issued.

May 1, 2005

By G. Righettini, G. Desrivières, P. Mousset-Jones, R. Lacroix, M. C. Bétournay, P. Laliberté, S. Hardcastle

"Under the requirement to define the economic advantages of using hydrogen fuel cell vehicles, a broad-scoped project was initiated to quantify the costs associated with operating fuel cell vehicles and diesel vehicles. While ventilation savings are clearly an advantage for the former, a complete and detailed analysis of this and other operational and capital cost elements was undertaken in order to provide the mining industry with factual information in considering the changeover from one technology to another.This paper outlines the results of the investigations to date defining the costs/benefits associated with capital purchases, operations (electrical/diesel, mine air heating fuel, ventilation, openings, surface and underground infrastructure, maintenance, labour, etc.), delivery of energy, regulatory obligations, and mine production. Considerations are given to the type and size of a mining operation, the depth, and location in North America.Significant ventilation power, equipment, and infrastructure savings are possible with the application of fuel cells for shallower mine applications. At depth, where heat is an issue, there is a reduction in benefit. Specific qualifiers such as minimum air velocities, dust dilution, shaft, and heating system velocity limits must be considered on an individual mine basis. While the capital cost for fuel cell mining equipment is currently higher than diesel versions the high cost of fuel cells is anticipated to be reduced significantly in the near future with the intensification of manufacturing. In either case, the operational savings would probably be sufficient to balance the supplementary capitalization costs.Comprehensive reports have been issued."

Jan 1, 2005

"The Antamina orebody is a geologically complex, polymetallic skarn located in the Peruvian Andes. A range of copper and copperzinc ores are campaigned separately through the concentrator producing copper and zinc concentrates as well as lead and molybdenum by-products.Ore type classification at Antamina is based on chemical assays; geological or lithological variations are not considered. Consequently, each ore type demonstrates a wide range of concentrator performance.Antamina is currently implementing a system to track ore movements from the shovel face to the concentrator. Relatively sophisticated models of run-of-mine and coarse ore stockpiles ahead of the mill will be used to account for the variable delay between mining and milling.One of the numerous benefits of ore tracking is the ability to directly associate the measured concentrator performance with a physical location in the orebody. Using existing mine planning software, three-dimensional models can be created of such performance measures as metal recovery, concentrate quality, operating cost, and reagent consumption.Such a database of information allows the true value of different ore sources to be determined. The value of an ore source is conventionally measured as metal content (individual or combined ‘equivalent’) with a cut-off grade applied to indicate some base level operating cost. However, the true value of an ore source should include dynamic factors like haulage cost, reagent use, smelter penalties, and even prevailing metal prices. If an ore source is considered from all perspectives rather than simply its potential to deliver value, the concept of ore becomes more flexible. Any ore source that reveals itself to be unprofitable can be eliminated from the mine plan or possibly blended with others to improve its value. The ability to predict mill performance, and thereby profitability, is a powerful tool.In an operation such as Antamina, where managing ore sources, campaigns, and the delivery of a variety of concentrates in a narrow timeline to customers is a daily challenge, prediction is the key to success and improved efficiency."

Jan 1, 2005

By G. Mihaylov

The basic principles of systems analysis are presented. A model has been designed to determine the location of the Main opening in the presence of three or more stock orebodies. The necessary condition is to find a location for the Collection point which is an essential element in opening up each orebody (stock). The model takes into account the total transportation costs from each orebody to the collection point. Three variants are considered provided that the orefield is divided into two levels at least: - a collection point is designed at every level; - a collection point is designed at the lowest level, i.e. where the so-called concentration level is formed; - the collection point is located at a point between the planes of the two levels; The effect of the depth of mining and mine output on determining the method of opening up the orefield has been analyzed by considering a vertical and/or an inclined shaft. A function has been constructed which allows for investigating in both a static and dynamic regime the capital costs for constructing the whole complex including the shaft. The character of the function does not allow finding the global limits. Therefore, it is of particular importance to specify the limiting conditions. In this case these are the flow capacity of development openings and the shaft. The basic groups of cost and natural indicators for assessing and selecting an optimal technological solution have been systematized. The combined analysis of the two approaches to finding the location of the Main opening and determining the mining method enables us to determine when an inclined shaft is best, and the depth at which opening by a vertical shaft has no alternative. Thus, a transition area is formed for which the selection of an optimal technological solution requires an analysis similar to that proposed in this paper. Conclusions are finally drawn which serve as a basis for determining the areas of application of each opening, including the use of a combined scheme of mine opening. The approach presented can be used in both investigating the possibilities for opening up new orefields and reconstructing existing ones in cases when the mining operations go deeper.

Aug 1, 2013

By L. Vollert

In August 2018, the first full-scale HydroFloatTM cells for the recovery of coarse composited copper and gold were commissioned at Newcrest’s Cadia Valley operation in New South Wales, Australia. The primary objective of the installation is to recover coarse value-bearing composites that are lost to conventional flotation tailings, without the need for additional power input for particle size reduction to improve mineral liberation. This paper examines the application of Eriez HydroFloatTM technology for the recovery of coarse, poorly liberated copper sulphide particles drawing on recent experience from lab scale testwork through circuit design and commissioning of the full-scale installation at Cadia Valley. INTRODUCTION In the face of declining copper head grades and a tightening regulatory environment around the use of wet tailings dams, the processing of copper ores at coarser particle sizes has become a focal point for the industry. Sulphide flotation using the Eriez HydroFloatTM is one of the emergent technologies that sits under this umbrella of coarse pre-concentration. It has been demonstrated through numerous lab and pilot scale testwork programs carried out by Newcrest and others (Awatey, Kohmuench, Thanasekaran, Skinner & Zanin, 2013), to improve the flotation recovery of sulphide-rock composite particles with low surface liberation, relative to conventional flotation technology. The HydroFloatTM technology has been used widely for the recovery of coarse potash, phosphate, coal, vermiculite, spodumene and diamonds but has never been applied at full scale in either gold or sulphide flotation. In August 2018, the first full-scale 3.4 m diameter HydroFloatTM cells for the recovery of coarse composite copper and gold were commissioned at Newcrest’s Cadia Valley operation in New South Wales. The primary objective of the installation is to recover coarse value-bearing composite particles that are lost to conventional flotation tailings, without the need for additional upfront power input for particle size reduction to improve mineral liberation.

Jan 1, 2019

By K. Purazrang, P. Musavi Garavi, P. Sh. Naseri, P. Abachi

The fracture behavior of high strength Al7050 alloy was investigated at room and elevated temperatures using small size, V-notched tear (called Kahn specimen) and compact tension, CT, specimens, respectively.To study the elastic-plastic behavior of the alloy, the tensile test was also performed on the sub-sized cylindrical tension test specimen. The microstructure of the alloy was examined using optical- and scanning electron- microscopy. The rupture mechanisms and crack path were also studied by examination of specimens' fracture surfaces using SEM. The microstructure examination revealed equiaxed grains and some elongated grains in rolling direction, with the areas of partial re-crystallized grains where coarse intermetallic particles are mostly found.In general, fracture surfaces were indicative of dimpled ductile type. Considering the fractographs of tensile specimens, the void growth mechanism is also dominant in fracture of these specimens. Nevertheless, in some regions, smooth areas can be observed due to the friction during rupture process. The results of mechanical tests at RT made the evaluation of tear strength to 0.2 % tensile yield strength ratio, as a measure of notch toughness, available. According to elevated temperature, 150°C, test results and plots of log da/dt vs. log KI , the crack propagation behavior over discrete ranges of crack growth rates could be assumed linear and then be obeyed as a power law equation in the form of da/dt = A (KI)n .

Jan 1, 2015

By N. Hiroyoshi, R. D. Corpuz, M. Ito, Hokkaido University, C. B. Tabelin, S. Veerawattananun

"Acid mine drainage (AMD), the very acidic and heavy metal-contaminated leachate generated when pyrite-bearing rocks are exposed to surface oxidizing conditions, is a serious environmental problem encountered after the closure of mines and mineral processing operations. In this study, we investigated the effects of soluble phases and metallic oxides, which are commonly found in strongly weathered pyritic wastes, on pyrite oxidation. Strongly weathered pyrite containing melanterite (FeSO4·7H2O) as the main soluble phase was obtained from Furikusa mine, Japan. The sample was washed using two methods to vary the relative amounts of melanterite in the sample. The effect of metallic oxides on pyrite oxidation was evaluated using ultrapure hematite suspensions. Our results showed that under acidic conditions, the effect of soluble salts on the oxidation of pyrite was stronger than hematite. More thorough washing of the sample resulted in the formation of an arsenic-bearing iron-oxyhydroxysulfate coating that minimized pyrite dissolution. This oxidized layer became relatively thicker and mechanically stronger when hematite was introduced after the more thorough removal of soluble salts. Characterization of this “coating” coupled with geochemical modeling suggest that it is most probably composed of two materials: schwertmannite and scorodite. Based on these results, a new approach to suppress pyrite oxidation by directly using iron-oxyhydroxysulfate as coating material is introduced.INTRODUCTION Acid mine drainage (AMD), the very acidic and heavy metals-contaminated leachate produced in closed/abandoned mine sites (Evangelou, 1995), mineral processing and coal cleaning tailings (Evangelou, 1995), and tunnel construction waste rocks (Tabelin and Igarashi, 2009, Tabelin et al., 2012), is one of the oldest and probably the most serious environmental problem of anthropogenic origin. When released to the environment, it rapidly pollutes river, soil and groundwater systems leading to the destruction of affected ecosystems. AMD is produced when pyrite (FeS2), one of the primary gangue minerals in sulfide ores and coals, is exposed to oxidizing conditions as illustrated by the following reactions:"

Jan 1, 2016

By Rick Collins

Presentation Agenda 1.Sudbury Basin 2.Diamond Drilling 3.Planned Production 4.Safety 5.Timeline 6.Sustainable Development 7.Scope Elements 8.Progress 9.Delivery Approach 10.Owners and EPCM Roles 11.Contract Styles 12.Mine Systems & Technologies 13.Q & A

May 1, 2009

By M. P. Amsden

"Ecstall Mining Limited, a subsidiary of Texas Gulf Incorporated operates the Kidd Creek Mine, a 10,000 tons per day base metal producer, near Timmins, Ontario. Two different ore types are mined and milled: copper-zinc and silver-lead-zinc. At the highly automated Ecstall Concentrator the ores are processed by selective flotation in threes individual circuits. One of the most important metallurgical tools for process control is a sample system incorporating continuous on-stream x-ray analysis. Recently this system was further automated by adding computer control of reagents for two copper-zinc flotation circuits. The computer programs, utilizing optimum seeking methods and smelter contract terms, have increased copper recovery 0.8%, zinc recovery 1.6%, and reduced reagent costs by 12%. Although not anticipated, copper and zinc concentrate grades were improved modestly as well.INTRODUCTIONSEcstall Mining Limited, a wholly owned subsidiary of the Texas Gulf Incorporated operates the Kidd Creek Mine, one of the world's major base metal producers, near the old gold mining centre of Timmins, Ontario. Discovered in 1964, the property was brought into production in November, 1966. Originally designed for 9,000 tons per day, the operation now treats 10,000 tons per day of two different ore types mined from a single open pit. In the near future, open pit ore will be supplemented by ore from an underground operation now being readied for productionAt the Ecstall Concentrator the ores are processed by selective flotation in three individual circuits. The whole plant is highly automated and control is coordinated from a central control room. The treatment process follows conventional practices although fine grinding is required for optimum flotation recoveries. Normally, two circuits treat copper-zinc ore at a combined rate of 6,500 tons per day while the third circuit treats 3,500 tons per day of silver-lead-zinc ore. Special production averages 2,400 tons per day."

Jan 1, 1973

By Donald F. MacDonald

WE are living in a mineral and technological civilization. The Encyclopedia Britannica defines civilization as follows: "It is the final test of a progressive civilization that a given effort shall produce a larger modicum of average individual comfort, and the pursuit of this ideal has been from first to last the impelling force which drives civilization onward". This "individual comfort" demands labour-saving machines and devices such as motor cars, radios, and thousands of other inventions, most of which require minerals and metals in vast quantity for their manufacture. In fact, more minerals and fuels have been used in the last third of a century than in all previous world history. Since 1800, the world's production of metals has increased more than a hundred fold (1). Scientific discovery is now advancing on a wide front, thanks to the research work that is being carried on in progressive countries. The world's work is now being done with very much less human drudgery than in the past. We do not have to toil for our living as our ancestors did, even if we follow their occupations. The average man has had many years added to his life-span, but, apparently, little to his spiritual stature and less to his common sense.

Jan 1, 1939

By R. P. van Hille, N. Mooruth

Remediation of acid rock drainage (ARD) was performed within a linear flow channel reactor (LFCR) via a floating sulphur biofilm (FSB). A full sulphur species material balance was conducted in order to characterize the sulphide oxidation. The reactor was able to achieve an 82% and 93% conversion of sulphide with a hydraulic residence time of 2 and 5 days respectively. 92% and 55.5% of the converted sulphide reported to the biofilm as sulphur for the 2 and 5 day residence times respectively. The mass transport limitations within the biofilm were identified via a dissolved oxygen gradient profiling system.

Jan 1, 2011

By Horace Freeman

The sulphur consumed in Canadian pulp mills and acid plants is worth approximately three million dollars annually and amounts to one hundred and fifty thousand long tons, all of which is imported from the United States. Concurrently with a decline in the value of newsprint there has been a gradual increase in the price of this raw material. Most pulp mills in Canada are situated within reasonable distance of domestic pyrite deposits; nevertheless it has not yet been found possible to mine these deposits and utilize the contained sulphur in competition with the imported material. It is the purpose of this paper to elucidate the reasons therefor, and to describe? a commercial-scale experiment undertaken with the object of introducing a native raw material into the Canadian pulp industry on the purely economic basis. Reasons for the Preferred use of Sulphur The known sulphur deposits in the United States are very large, so that at least a twenty-year supply of this material is assured. It is recovered cheaply and in pure condition. Although large deposits of pyrite are known in Canada, nothing has yet been developed to compare in size, cost of mining, or purity with the United States material. It has been necessary to handle and transport more than two tons of pyrite to equal a ton of sulphur.

Jan 1, 1930

By F. Dai

Granitic rocks usually exhibit strongly anisotropy due to pre-existing microcracks induced by geologic loadings. The understanding of the rock anisotropy in mechanical properties such as tensile strength is critical to quarrying and stabilization of underground structures. In this paper, Brazilian tests are conducted in combination with MTS material testing machine and split Hopkinson pressure bar (SHPB) system to measure both static and dynamic tensile strength of anisotropic Barre granite. Samples are cored and labeled using the three principle anisotropic directions of Barre granite (BG). These directions are also chosen as the loading directions for the Brazilian discs. For dynamic tests, pulse shaping technique is used to achieve dynamic equilibrium in the samples during the test. Finite Element Method is implemented to formulate equations that relate the failure load to the material tensile strength employing a orthotropic model for Barre granite. For samples in the same orientation group, the tensile strength shows clear loading rate sensitivity. The tensile strengths exhibit clear anisotropy under static loading; while less anisotropy under dynamic loading. The tensile strength anisotropy of Barre granite is interpreted as interactions of the pre-existing microcracks.

May 1, 2009

By Timothy R. Eby

"The Wabush Mines project was formed in 1956 to develop a large iron ore property in Western Labrador. The town of Wabush along with the mining and concentrating facilities are located 640 air miles from Montreal, and 734 air miles from St. John's. The operation has been in production since late 1964.While mining and concentrating operations are located in Labrador, the pelletizing facilities are situated 275 miles south at Sept-Iles, Quebec. Dedicated in 1965, Wabush produces six million tons of high quality iron ore pellets annually. The company employs 1, 550 people at Wabush and the Pointe Noire plant at Sept-Iles.Wabush Mines is an unincorporated joint venture of three companies -The Steel Company of Canada, Dominion Foundries and Steel Ltd. and the remaining 58% by the Wabush Iron Co. Ltd. Wabush Iron Co. Ltd. is in turn owned by six companies: The Youngstown Sheet & Tube Company, Inland Steel Company, Interlake Inc., Wheeling Pittsburg Steel Company, Finsider International S.A. and Pickands Mather & Company which is also managing agent.The town of Wabush is set in a remote part of Northern Canada accessible only by rail and air transportation. But this in no way has hindered the growth and development of the area. Modern housing units, shopping facilities, airport and of course, recreational facilities are all patt of every day living amenities, an accepted aprt of southern communities, but quite unique for northern isolated mining localities."

Jan 1, 1978

By J. R. Andrews, R. P. Young, J. M. Reyes-Montes

"Microseismic monitoring provides insight into the location and extent of rock-mass fracturing induced by cave mining, enabling interpretation of the cave profile and validation of predictive numerical models. Source location uncertainties can lead to misinterpretation of the inferred characteristics of the fracture network. One principal source of uncertainty is the velocity model used to invert the location algorithm. Large-scale 3D numerical models of modulus changes across a caved mass can represent such complexities in the location algorithms, allowing more accurate interpretation of the microseismic activity. A Northparkes mine case study applies this advanced approach to microseismic data interpretation.RÉSUMÉ Le suivi microsismique fournit des renseignements sur la localisation et l’étendue des fractures de la masse rocheuse induites par l’exploitation par blocs foudroyés; cela permet d’interpréter le profil de la chambre foudroyée et de valider les modèles prédictifs numériques. Les incertitudes quant à la localisation de la source peuvent conduire à des mésinterprétations des caractéristiques inférés du réseau de fractures. Une des principales sources d’incertitudes est le modèle de vitesse utilisé pour inverser l’algorithme de localisation. Des modèles numériques tridimensionnels à grande échelle des changements du module d’élasticité à travers une masse foudroyée peuvent représenter de telles complexités dans les algorithmes de localisation, permettant ainsi une interprétation plus juste de l’activité microsismique. Une étude de cas à la mine Northparkes applique cette approche avancée à l’interprétation des données de microsismicité."

Jan 1, 2016

By A. Griffiths, G. Vickell

"INTRODUCTIONA successful cyanide destruction process has to ensure environmental compliance at reasonable cost. That this is possible with hydrogen peroxide is shown by the fact that over twenty gold mines either already use H2O2 or intend to start using it within the next few months. About half of these mines are in Canada.This growth is remarkable, considering that the first treatment plant to use H2O2 for detoxifying cyanide was commissioned less than five years ago at Ok Tedi, in Papua New Guinea.Hydrogen peroxide is being applied to a wide range of situations, including:Treatment of CIP pulps; examples: Ok Tedi, PNG; Hope Brook, Nfld.Treatment of barren bleeds and filtrates; examples: Nickel Plate, B.C.; Puffy Lake, Man.Treatment of tailings pond discharge; examples: Detour Lake, Ont., Page Williams, Ont.Treatment of excess heap leach solution; examples: Hope Brook, Nfld; Gordex, NS.Treatment of barren heaps after heap leaching; examples: Alhambra, NV; Wharf Resources, S.D.Treatment of pond reclaim water to prevent either ""preg-robbing"" or depression of gold-bearing pyrite in a flotation step; example: Getchell, NV.Treatment of backfill to prevent possible groundwater contamination; example Hope Brook, Nfld.Treatment of tailings ponds to prevent bird kills; example: Paradise Peak, NV.""Emergency"" units to deal with unusual events such as freak storms or dam failures."

Jan 1, 1989

By P. E. Cavanagh

"The Davis tube test has been used for many years as a laboratory method for determining the magnetic iron re-coverable from a magnetite iron orebody. This paper de-scribes a method for determining the recoverable iron from ores of the Labrador Trough type, with the usua1 flow sheet utilizing spirals followed by magnetic separation.The mechanical structure of a metamorphosed iron ore, resulting from recrystallization over long periods of time, is the basis for the laboratory method developed. Similarities between the structures of such recrystallized ores and the structure of annealed and recrystallized steel are noted.A laboratory technique to determine the size of the different grains of gangue and iron ore minerals is de-scribed and the application of this information to arrive at recommended grinding techniques and flow sheets is demonstrated. The use of the method to determine recoverable iron in such ores is compared to actual iron recovery in the pilot-plant and commercial concentrations of the same ore.The use of a specified lower limit of recoverable iron as determined by this method, in order to design open-pit limits, achieves practical results when compared to designing a pit based on an arbitrary lower limit of total soluble iron. The Ungava Iron Ore deposits are used in giving an example of the resulting pit design changes."

Jan 1, 1968

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