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In 2007, a total of 7,199 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 ? Sand and gravel mines were the largest mining sector, comprising 48.4% of all mining operations. ? Sand and gravel mines were found throughout all 50 states and Puerto Rico.

Aug 1, 2009

By D O’Dea, B Godel, T Honeyands, B Ellis, T Harvey

X-ray computed tomography (XCT) is a non-destructive technique that allows the exploration of the internal structure of solid objects in 3D. Over the past ten years, the combination of XCT with more conventional 2D techniques and quantitative 3D image processing and analysis (commonly referred to as digital rocks) has allowed us to address some of the most challenging problems in ore deposit studies. The range of X-ray energies used in XCT allows the X-rays to be transmitted through complex and dense materials including iron ores (eg sinters, lumps, granules). Recent high-resolution XCT scanners have the ability to generate multiscale (25 down to 0.3 µm voxel size) imaging of a given sample enabling the characterisation of 3D textures across a range of scales. This paper will focus on the application of digital rocks to iron ore sinter particles (using filtered polychromatic X-ray beam). The paper is divided into three parts and includes: i) details on the methodologies including their benefits and limitations and the effect of spatial resolution; (ii) the quantification of pore network topology and pore characteristics (eg open versus closed pores, pore size distribution and pore morphologies; degree of connectivity of the pore network and its tortuosity); and (iii) the evaluation of the technique to characterise various phases within the material and quantify 3D mineral textures.CITATION:Godel, B, Ellis, B, O’Dea, D, Honeyands, T and Harvey, T, 2017. Digital rocks for iron ore sinters – towards a D quantification of sinter textures, in Proceedings Iron Ore 2017, pp 529–534 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By CLARENCE G. SMITH

Prior to the actual development of an oil property it is difficult to determine the quantity of oil under the property and the rate at which this oil can be brought to the surface-factors that determine the ultimate value of the property. Consequently, there has been much confusion in devising accounting systems that, during the entire life of a property, will show costs and profits from which the producer can determine whether his property is being worked at a profit or otherwise. The Bureau of Mines publishes this report in recognition of a distinct need for a simple treatise on accounting methods adapted to the peculiarities of the petroleum industry. Probably many companies operating oil wells are not fully acquainted with details important to the welfare of their business, because their account books fail to furnish them with exact and adequate data. With the accountant rests the responsibility of providing the management with reports setting forth the details of the business expressed in fitting terms as well as in dollars and cents. These reports are a means whereby efficiency may be maintained, waste prevented, oil obtained and sold, and money suitably reinvested. They also enable a concern to study the progress of its business in order to conserve to the utmost the possible benefits from an exhaustible deposit of mineral wealth. When managements realize the extent of the waste at their properties more attention will be given to the character of the accountancy records. Herein are presented descriptions and discussions of balance sheets, profit-and-loss statements, and bookkeeping methods peculiarly adapted to the oil business. As far as possible, technical phrases have been omitted in order that those not familiar with accounting terms may be able to follow the subject matter. The systems of keeping books outlined in Chapter X have all been found practical. For brevity as well as clearness the major part of the work refers to the company operating only one property.

Jan 1, 1917

By J Missen, P Currie, J Bohan, D Clark

AGL is one of Australia’s leading integrated energy companies and the largest ASX listed owner, operator and developer of renewable energy and thermal generation in the country. AGL owns and operates the 2210 MW Loy Yang A power station and adjacent 30 Mt/a brown coalmine in the Latrobe Valley, Victoria. It also supplies coal to the nearby 1050 MW Loy Yang B power station owned by the GDF Suez (Engie)/Mitsui partnership. The mine is currently nearly 5 km long, more than 2 km wide at the operating face and up to 200 m deep. AGL employs a large workforce at Loy Yang and a substantial amount of services are performed on-site by contractors and consultants.GHD provides mine planning, earth sciences, civil/geotechnical engineering, dam surveillance, plant engineering and environmental services to AGL Loy Yang through an alliance framework. GHD is one of the world’s leading professional services companies operating in the global markets of water; energy and resources; environment; property and buildings; and transportation. In addition to GHD’s global footprint, the company also has a significant Victorian presence, including a permanent, well-resourced regional office in Traralgon, approximately 10 km from Loy Yang, as well as a permanent site office.A joint paper on the Loy Yang mine professional services alliance model was written for the AusIMM International Mine Management Conference in 2006 by Woods and Wood. Now ten years on, this paper provides an overview of the present relationship and arrangements, including the continued transformation of the alliance model and maturing of the relationship contract.These are challenging times, with increasing cost and regulatory pressure driving change in the broader energy and resources industry, and locally including both the mining and power sectors at Loy Yang. Flexible models to achieve a balance between internal personnel and access to key external skills, whilst achieving value for money and transparency, is increasingly critical. The right drivers and performance measures are essential, particularly when confronted with potential major technical and environmental risks (considering significant ground failure and fire events that have occurred elsewhere within the Latrobe Valley over the last decade) within a sector that is reducing costs and optimising production.This case study discusses the alliance status and changes, reasons behind adjustments and what the future is likely to hold. The paper also explores the validity of the original objectives and the extent to which they have been achieved. The philosophy of the alliance is to continue closely aligning the objectives of the two companies in the best interests of the Loy Yang site and immediate surrounds/stakeholders. Quality of service, costs, timeliness, health and safety (H&S) and some operational activities (aquifer depressurisation) remain important aspects and are reflected in key indicators for which performance is measured.CITATION:Clark, D, Bohan, J, Currie, P and Missen, J, 2016. AGL energy, Loy Yang and GHD – a further case study in alliancing: ten years on, in Proceedings International Mine Management Conference, pp 321-330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

Most types of nuclear power reactors use uranium dioxide fuel. Power reactors using natural uranium dioxide fuel are of special interest to countries such as Australia that have their own uranium supplies. A wide range of uranium dioxide powders can be fabricated and the ideal one flows readily, presses without the need for binders or lubricants, sinters to the required density and gives low reject rates at all fabrication stages. Sinterable uranium dioxide is usually produced via the ammonium diuranate route.The Australian Atomic Energy Commission is aiming to demonstrate production of nuclear grade uranium dioxide from Australian concentrates, improving technology where possible. Details are given of the dissolution, solvent extraction, precipitation, filtration, drying, and· calcination-reduction steps. Solvent extraction from sulphate media is also under study with a view to developing a process to produce a nuclear grade product at the mine treatment plant site.

Jan 1, 1970

By G. L. Oldright

The Metallurgical Branch of the Bureau of Mines, as a part of its duties under the Organic Act, works to prevent wastes in industry and to disuse inmate information on the fundamentals of metallurgical processes. During the war, the necessity of large production was increasingly emphasized. Such duties necessitate from time to time the study of units of full commercial size, the operation of which is beyond the facilities of the Branch. When developments have reached this stage; work has been continued in cooperative agreements with operating companies that have been willing to contribute the use of their plants and staffs and to allow the publication of the results obtained for the common good of the industry.

Jan 1, 1948

By R. F. Balazik

By March 2001, shrinking global markets, reduced consumer spending and declines in domestic manufacturing and industrial output ended the longest economic expansion in US history and pushed the nation’s economy into its first recession in a decade. Aggravated by the terrorist attacks of Sept. 11, the recession led to large reductions in the domestic production of processed mineral materials. Some of the most significant production declines in the US metals industry were registered by aluminum, copper and steel producers. They faced strong foreign competition, higher energy costs and lower prices for their products. However, homebuilding and other domestic construction sectors — major users of nonmetallic mineral products such as cement, brick, glass and stone — remained strong enough to help raise the output of industrial mineral materials slightly above previous year levels. A strong US dollar continued to weaken the competitive stance of US metal and nonmetallic mineral materials companies alike against foreign producers in markets at home and abroad.

Jan 1, 2002

By J. A. Marts

Reservoir properties including porosity and permeability distributions in longwall coal mine gobs have direct application to modeling the flow patterns and gas distributions in the gobs. Proper assessment of these distributions is required to assess gob gas hazards such as spontaneous combustion and explosive methane mixtures and to optimize gob gas venthole operation and nitrogen inertization. Determining the reservoir properties is difficult given that the gob is inaccessible and direct measurements cannot be easily taken. Several techniques had been used by previous researchers and will be discussed. This paper will present the methodology used to model the gob compaction by simulating the sequential extraction of coal. Two Western US coal mines were used for case studies. By determining volumetric strain, the porosity and permeability distributions in the gob can be calculated. The geo-mechanical model predicts an axisymmetric volumetric strain distribution with a steeper slope near the start-up room and a shallower slope near the active face.

In 2007, a total of 725 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Nonmetal mines com-prised 4.9% of all m ining operations. ? Mines producing common clay comprised 25.4% (n=184) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the U.S. Virgin Islands.

Aug 1, 2009

By Albert L. Toenges

The development of Alaska depends on the existence of an adequate fuel supply in the Territory. The need to investigate coal deposits was recognized as early as 1911, when the first investigations were conducted in Alaska by engineers of the Bureau of Mines. Conditions existing in the Bering River and Matanuska coal fields, as found by Dr. Robert A. Holmes, former Director of the Bureau of Mines, are described by the Honorable W. L. Fisher, former Secretary of the Interior./ Following Dr. Holmes' investigation, a party of Bureau of Mines engi¬neers headed by R. Y. Williams visited the Bering River field in 1912 in cooperation with the Navy Department. A detailed examination was made of the Bering River field, and 855 tons of coal were mined from three prospects on Trout Creek. This bulk sample was delivered to the Navy for steaming and other tests. A description of the work of the field party and results of tests of the coal by the Navy Department and the Bureau of Mines has been published.

Jan 1, 1949

By Guilherme L. M. G. Carvalho, Zachary T. Fleming

In a world of 2-dimensional design documents, envisioning and understanding 3-dimensional interferences for complex foundation construction scenarios can be challenging. Videos and computer models serve as 3-dimensional spatial aids but have drawbacks related to a fixed perspective. Augmented and virtual reality (AR/VR) provide new tools to communicate design challenges and improve construction planning. This paper provides a practical look at the basics of AR/VR systems and the tools available to the foundation design and construction industry by giving a high-level example of the technologies’ use in the design and delivery phases of a complex micropile installation project for the remediation of a dam foundation. Using these technologies, GEI was able to design and deliver a complex foundation remediation solution. AR/VR benefited regulators, and the client, to help understand the design concept, construction sequencing, and approach to overcoming installation challenges. Due to its user-friendly nature and less rigorous programming and hardware requirements, AR proved to be more useful than VR for this scenario. AR/VR will likely not replace videos and computer models; however, it can be a useful 3-dimensional visualization aid that complements the project delivery process and offers benefits that traditional methods cannot. INTRODUCTION Augmented and virtual reality is a promising and rapidly developing technology within the engineering and construction world. Like any rapidly developing new technology, the language describing it can be confusing and dynamic. To eliminate the confusion some definitions must be made. AR/ VR definitions The definitions of virtual reality (VR) and augmented reality (AR) for the purposes of this paper are as follows: VR is a computer-generated immersive environment that the user experiences within a digital 3- dimensional space (Satava, 1993)AR is a composite view created by superimposing digital objects into the user’s real-world view (Azuma, 1997). Often, VR is used in an office environment and allows the user to “visit” the digital site to review site planning, construction sequences, and interference geometry. AR can be utilized in both the office and onsite environments. Like VR, the in-office application for AR is commonly site planning. AR also can be utilized in the field for applications such as seeing through the ground to locate known existing obstructions like utilities, gas tanks, etc.

Jan 1, 2019

By Joseph J. Yancik

An exchange of coal mine specialists was made with the USSR under an "Agreement on Exchanges and Cooperation in Scientific, Technical, Cultural, and other Fields for 1972-73," which was signed by President Nixon and Chairman Breshnev on April 11, 1972.* This exchange, in the field of coal mine safety and scientific research in hazard control technologies, was one of 16 technical exchanges covered under the above agreement. A six-man USA delegation visited the Soviet Union from September 9 to September 21, 1973. The delegation visited four deep mines, three in the Donets Basin and one in the Moscow Basin, a State Safety Research Institute, a Mine Research Station and associated Research and Design Institute, two Research and Design mining equipment institutes, and a Trade Union-sponsored health sanitarium. In Moscow, the delegation received a briefing on the Soviet coal industry from First Deputy Minister Vladimir Fedanov. A similar briefing was given to us on the Donets coal basin by the Deputy Minister S. Saratikyanz of the Ukrainian Coal Ministry. Lengthy technical discussions were held with the mines staff and research personnel at the institutes we visited. In addition, we had detailed discussions with key staff members of two combinats "Donetskugol" and "Tulaugol." In all these meetings, principal topics were matters of safety related to hazards associated with face mechanization, coal transport, methane gas control measures, gas outbursts, coal and rock outbursts, fire fighting add control, explosion suppression and control measures and other related hazard factors. There was also much discussion on miner training, miner's attitudes toward safety and accident prevention practices, and preparation and enforcement of safety rules and regulations. The delegation was very warmly received and constant attention was given to our needs. Our numerous questions were answered with candor although quite often in not as much detail as we would have liked.

Jan 1, 1974

By S. M. Bradshaw, V. Rocher, L Kabondo, B. Combrink, C. A. Snyders

Media losses are a significant contributor to the operational cost in a dense media separation (DMS) circuit. Of these losses, up to 80 wt% can occur on the drain and rinse vibrating screens. Although these screens are an integral part of any DMS circuit, surprisingly little work can be found in open literature regarding the effect of aperture configuration on the drain rates (draining water and medium). To establish the effect of slot aperture size, experiments were conducted on a 0.6 x 1.2 m vibrating screen with polyurethane (PU) panels at slurry densities between 1.6 – 2.8 kg/L, and volumetric flow rates of 19 – 25 m3/h for both ferrosilicon and magnetite. Results showed that an increase in the volumetric flow rate led to an increase in drainage rate, moisture content and medium carryover. Once an optimum volumetric flow rate was exceeded, a further increase in flow rate resulted in a decrease in drainage rate with a sharp increase in moisture and medium bypass to the oversize stream. An increase in ferrosilicon slurry density led to a decrease in drainage rate with an increase in moisture and medium bypass with each of these rates increasing as the slurry density increased. For magnetite, a gradual decrease in drainage rate was observed with increase in slurry density and volumetric flowrate beyond the screen optimum point. It was found that an increase in aperture size from 0.63 x 8.8 mm to 0.8 x 8.8 mm to 1.0 x 13 mm resulted in an increase in ferrosilicon drainage rate of between 1.3 - 1.8 m3/m2/h depending on the flow rate and slurry density with a reduction in moisture and medium carryover of between 1.0 – 1.2 % and 14.1 – 20.2 kg/t/m respectively. For magnetite, the drainage rate increased between 1.0 - 1.4 m3/m2/h as the slot width increased from 0.63 x 8.8 mm to 0.8 x 8.8 mm while an increase in slot length from 0.63 x 8.8 to 0.63 x 12 mm only resulted in an increase in drainage rate of 0.1 - 0.5 m3/m2/h.

Jan 1, 2018

By Urie R. W

Fluidized bed roasting of copper concentrates from Mt. Morgan, Mt. Lyell, Mt. Isa, and Peko was performed in a 3 ft 6 in diameter, slurry fed, pilot plant roaster operated under autogenous conditions to produce calcines with desirable leaching properties. A 12 in. diameter, externally heated roaster, provided with a dry feed system, was also used.An account is given of important factors which influence roaster behaviour and performance, and the effects of operating variables on calcine composition and leaching properties are described. Due to copper ferrite formation, a maximum of approximately 50 per cent of the copper in the calcines may be in the form of CuO before the copper leach efficiency falls significantly below lOO' per cent. Recovery of gold by cyanidation of leach residues was consistently high and independent of roasting conditions.INTRODUCTIONIn traditional practice copper is produced by pyrometallurgical techniques when the ,copper minerals in the ore or concentrate are predominantly sulphides, and by hydrometallurgy when the minerals are oxidized. Copper smelting is most suited to large scale operations, and for many years small to medium size mines with sulphide orebodies have been interested ill; alternative processes.Since hydrometallurgical plants (ie. leaching and electrowinning plants) are essentially unitized, they may be scaled down in output without much loss in efficiency or increase in processing cost, and many proposals have been made for the application of this type of process following roasting of the sulphides to render the copper soluble. However, until the advent of fluidized roasting, it was not possible to control the roasting operations sufficiently precisely to produce calcines consistently of the required leaching characteristics.

Jan 1, 1961

By Maureen Jensen

For mining companies looking to establish a strong North American presence, raise their profile or finance and position themselves for future growth, there is no other destination in the world that can offer a mining company the same opportunities as Canada whether you are an established blue chip or promising junior. Despite historically poor world commodity markets and shaky investor sentiment towards junior explorers caused in part by fallout from the high profile Bre-X fraud, Canada continues to shine as the undisputed mining finance capital of the world. Our natural riches and mining history go a long way to explain Canada's international prominence in mining finance. Canada has actively created and maintained one of the most integrated national frameworks to support mining ventures of all kinds. Our diverse industry, from one-person grass-roots explorers to mining industry giants, is one of our main strengths whether your company is Canada-focused or internationally active. The mining industry continues to be a vital contributor to the Canadian economy, contributing $26.2 billion in 1997 or 3.8% of national GDP, and is the second largest earner of foreign exchange. Industrial mineral companies are a very important part of this strength. These companies require a continuing access to capital to ensure that they can continue to compete and the globalisation of the Canadian mining industry has affected this industry just as much as it has affected every other industry in Canada.

Jan 1, 2001

By Dan Nilsson

INTRODUCTION There are many mine planning factors in sublevel caving, as in the other mining systems, which when varied can substantially alter mining costs and profit¬ability. In this chapter, the following four topics are addressed with regard to economic optimization of sub¬level caving: production planning, haulage level spacing, orepass spacing, and extraction cutoff. The costs used here are the right order of magnitude but since each mine is unique, they should be considered only as examples. The objective is to demonstrate the tech¬niques which can be used. In a real mine, the evalua¬tions must be done using actual costs and conditions. It is difficult to predict exactly the costs involved, and therefore it is valuable to perform a sensitivity analysis to evaluate the effect of making incorrect as¬sumptions. Since the mining industry is very capital intensive, the effect of the interest rate must also be studied. PRODUCTION PLAN FOR AN IRON ORE DEPOSIT Introduction The first and most important thing to do before de¬signing an underground mine is to establish a long-range production plan. Such a plan is necessary for all eco¬nomic evaluations and should provide information about the lifetime of the mine, how much ore and waste must be handled per year, how much development per year is required, etc. An example is given in the following section. Problem In an iron ore mine sublevel caving is used. The iron content is 42%, and the mine supplies a pelletizing plant with an annual capacity of 3 million t/a. The ore body is shown in Fig. 1. The length of the ore body is 1000 m and the width is 100 m. Each slice is 10 m high, and there are 10 m be¬tween crosscuts, each of which has an area of 20 m2. The density of the ore is 3.5 t/m3. The spacing between rings is 2 m, and the extraction is 100%. The iron con¬tent is 66% in the pellets and 6% in the tailings. The problem is to develop a detailed production plan. A typical sublevel caving sequence is shown in Fig. 2. Solution Amount of ore per meter of crosscut: 20 X 3.5 = 70 t. Number of crosscuts per slice= 100. Length of crosscuts per slice: 100 X 100 = 10 000. Ore from crosscuts per slice = 10 000 m X 20 m2 X 3.5 = 700 000 t. Number of sublevel caving rounds per slice: 10 000/2 = 5000. Area for each blast in sublevel caving: 10 X 10 - 20 = 80 m2. Amount of ore per blast: 80 m2 X 6 m X 3.5 = 560 t. Extraction: 100% (see extraction curve Fig. 12). Loaded ore per blast: 75% or 420 t. Loaded waste per blast: 25% or 140 t. Total: 560 t. Total amount of rock from each blast in the sublevel caving: Ore: 560 t of which 2 X 70 = 140 t from develop¬ment work and 420 t from sublevel caving. Waste: 140 t. Total: 700 t. The ore needed per year is 3 X (66-6)/42-6 5 mil¬lion t. Necessary number of blasts per year= 5,000,000/ 560 = 8929. Distance to develop per year = 8929 blasts per year X 2 m per blast 17 858 m. Total amount/year: Ore from development work 17 858 m x 70 t/m = 1.25 million t/a Ore from sublevel caving: 8929 blasts per year X 420 tons per blast = 3.75 million t/a 5.00 million t/a Waste rock dilution: 8929 blasts per year X 140 tons per blast 1.25 million t/a Total amount to hoist 6.25 million t/ a The amount of ore from development work will in¬crease a little if the horizontal drift is placed in the ore body and not in the footwall. In this example the ore loss in 20%, and the waste rock dilution is also 20%. After taking the ore loss into account, the lifetime for 100 m of the ore body will be:

Jan 1, 1982

By Enver Alan

This Research & Development (R&D) study was conducted in the field of applied blasting engineering in Ethiopia, within the AKH Railway Project, which was built in Girena, within the boundaries of the province of Mersa, in the Basalt Quarry at km 346, Ashangi Formation, occured in Eocene geological time in the aphanitic trachibasalt. Under the scope of the study, which has been performed to determine the effects of the artificial discontinuities at different depths and the effects of artificial discontinuities through structural damage risk, three test areas, at the same location and same formation, were considered. Six numbers of artificial discontinuities, each 10 m (32, 81 ft) transverse, were created by using pre-splitting and drilling-blasting technology. The number of sequential artificial discontinuities on each test area is two and they have the same length. The length of artificial discontinuities are; 6,80 m (22,31 ft) at the first test area, 13,60 m (44,62 ft) at the second test area and 17,00 m (55,77 ft) at the third test area respectively. The distance between sequential artificial discontinuities is 8 m (26,25ft) on each test area. Thirty-one shots were executed in order to produce vibration (10 shots on the first test area, 11 shots on the second area, 10 shots on the third test area). One hundred and twenty-three seismic recordings were obtained during the execution of the shots by using 4 seismographs. The closest distance between the shot points and the nearest measuring station is 5,30 m (17,39 ft). During the shots, the rock was cracked and there was no fragmentation and/or fly rock. At the first test area, measured PPV values are between 25,40-127,00 mm/s (1-5 inch/s) before the first artificial discontinuity and less than 50,80 mm/s (2 inch/s) after the second artificial discontinuity. At the second test area, measured PPV values are between 76,20-177,80 mm/s (3-7 inch/s) before the first artificial discontinuity and less than 76,20 mm/s (3 inch/s) after the second artificial discontinuity. At the third test area, measured PPV values are between 50,80-279,40 mm/s (2-11 inch/s) before the first artificial discontinuity and less than 50,80 mm/s (2 inch/s) after the second artificial discontinuity. Peak reduction rates in Peak Particle Velocity (PPV) values determined by measuring as follows: In the first test area 95,77% (106,00 mm/s to 4,48 mm/s) (4,17 in/s to 0,18 in/s), in the second test area 79,77% (176,00 mm/s to 35,60 mm/s) (6,93 in/s to 1,40 in/s), in the third test area 95,85% (from 205,00 mm/s to 8,55 mm/s) (from 8,07 in/s to 0,34 in/s). The arithmetic mean of the differences of PPV values (decrease rate) is 82,66% in the first test area, 69,37% in the second test area, and 92,03% in the third test area. The highest sound value is 138,50 dB and is defined as “noise”. When the measured parameter values are examined it was determined on the USBM norm graphs that these vibrations carry a risk of structural damage in the region before the first artificial discontinuity. While passing through artificial discontinuities the vibrations progress by losing energy and the vibrations passing through two artificial discontinuities do not carry structural damage risk under current conditions.

By D. M. Doyle

A study of the various components contributing to energy costs and their relationships to generally trended operating data, such as tonnage, operating costs, etc., over progressively shorter time periods provides information for an energy audit. A study of annual data gives some insight into the importance of various energy components. As the time frame of the study progresses through monthly, daily and, finally, into quarter hourly data, the variations become more evident and, most important, strategies develop to minimize energy costs. The results of an audit conducted during the summer of 1978 at Wesfrob Mines Limited are reported to illustrate this important phase, prerequisite to a meaningful energy cost avoidance program. The balance of the paper deals with the energy conservation program at Falconbridge Nickel Mines Limited's Sudbury operations, the metering and control equipment, the commitment, the new energy accounting practices and, lastly, the policies. Examples of successful energy conservation endeavours include automatic peak electrical load control, waste heat recovery from mine air and compressor cooling water, energy reductions resulting from lower building temperatures and curtailment of idling loads. The use of pulse meters to measure the flow of gas, steam, compressed air and electrical energy, with their signals interfaced to process computers, allows monthly, daily and, if necessary, immediate reporting of energy and energy per unit of production information The program so reported at Falconbridge's Sudbury Operations is credited with an annual cost avoidance of .9 million dollars in a 14.0-million-dollar annual energy account

Jan 1, 1979

By R Beaulieu, D Burlingame, C Hanks

The Ekati Diamond MineÖ is CanadaÆs first diamond mine and is located 300 kilometres northeast of Yellowknife in the Northwest Territories. The development of the mine supports sustainable development through the integration of environmental, economic and social considerations with the broad aim of minimising environmental impacts while maximising opportunities and benefits to northern residents and northern businesses. The environmental assessment and regulatory processes for the Ekati Diamond MineÖ were the most extensive seen in the NWT to that date; in Canada only uranium mines receive more attention. In addition to the regulatory requirements, an Environmental Agreement was negotiated with the Governments of Canada and the Northwest Territories to address environmental concerns not covered by existing legislation and regulation. Under the agreement an Independent Environmental Monitoring Agency was set up to oversee the regulatory process and implementation of the Environmental Agreement. Environmental stewardship is implemented through an Operational Environmental Management Plan, part of which includes effects monitoring programs for wildlife and aquatics where available traditional ecological and scientific knowledge are integrated to broaden our understanding of the tundra environment. A Socio-economic Agreement was concluded with the Government of the Northwest Territories to maximise employment and business benefits to the north. Voluntary and confidential Impact Benefits Agreements (IBAs) were also negotiated with four Aboriginal groups who use the area where the mine is located. The intention of the IBAs is to foster development initiatives and a partnership thereby helping to insure that benefits from the project flowed to the Aboriginal groups despite a lack of settled land claims in the region. All these were completed before commercial production in October 1998. Employment targets of 62 per cent residents of the Northwest Territories and 31 per cent Northern Aboriginal have consistently been met thereby ensuring benefits flow to residents of the Northwest Territories. In 2000, $316 million was spent to support operations at the Ekati Diamond MineÖ. Of this, 82.2 per cent of total spending and 26.6 per cent total northern spending was northern and northern Aboriginal businesses, respectively. The environmental and socio-economic monitoring results are reported annually to the responsible government agencies and potentially affected Aboriginal groups. To date, there have not been any significant adverse environmental effects documented and socio-economic targets have been met.

Jan 1, 2002

By J. Arzuúa, U. Castro-Filgueira, L. R. Alejano, F. Malan

"Pillar design for underground mining is typically done using empirical formulae or numerical modelling. Practical experience and recent literature, nevertheless, illustrate the shortcomings of these design approaches. Ongoing monitoring of pillars is therefore recommended to minimize the risk associated with these designs.In a mine where a large number of pillars are cut, different pillar strengths can be expected owing to variations in rock mass strength from area to area. This problem is compounded by the fact that in mining environments the pillars are not always cut according to the prescribed dimensions. Although the original design using either empirical methods or modelling may predict stable pillars, unstable pillars will be encountered in reality. Very conservative designs with large factors of safety may circumvent this problem, but this approach is uneconomical.A possible solution to localized stability problems may be to enhance the strength of a few unstable pillars. It may even be hypothesized that reinforcing a few critical pillars may prevent ‘pillar runs’ on a much larger scale. Rockbolting, strapping of pillars, and pillar shotcreting have occasionally been used in the past as possible solutions. It appears that these have not been successful in all cases and large collapses have occurred in spite of the pillar remedial work.The authors investigated the strapping of pillars by conducting laboratory tests on cabled rock specimens. The results were qualitatively compared to actual attempts of pillar reinforcement available in the literature, as well as additional observations in an old haematite roomand- pillar mine in Spain. Based on these results, the value of steel cabling and mesh wrapped around pillars to improve stability is demonstrated. Some cases where this approach will not be successful are also discussed."

Jan 1, 2017