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By Alex Rown

"THE SYDNEY COAL FIELD has long been afflicted by high costs and low productivities. However, a distinct possibility now exists that improvements can be made in costs, productivities and revenues. If these hopes materialize, the Sydney coal field will once again be regarded as a valuable asset in our national inventory of energy and metallurgical coals. The economic possibilities for the Sydney collieries depend on performance at the pits and in the market place. Because this audience is already well informed about colliery planning, I would like to start with an assessment of the modern coal market insofar as it may relate to the Sydney field. Since 1950 we have seen a vast growth in the population and industrial empires of the western world which has resulted in an enormous and escalating demand for energy. If the energy supply pattern of the first 50 years of this century had been followed, this would have led to an immense demand for coal."

Jan 1, 1972

By Steve Kral

The mining industry has had three difficult years. Commodity prices have remained low and investor confidence in the industry has been shaken. And even though the Asian economy appears to be improving, it will be some time before this improvement will translate into better commodity price conditions for mining. In addition, increased environmental and social restrictions that have been placed on the industry in developed and developing countries have made mining a more difficult proposition. And, if that is not enough, the global mining industry has found itself in fierce competition with Internet businesses for investor capital. Despite that gloomy picture, more than 10,500 mining industry professionals from about 70 countries gathered in Toronto, Ontario March 5-10, 2000 for the Mining Millennium 2000 conference. This meeting was a joint effort between the Canadian Institute of Mining, Metallurgy and Petroleum(CIM) and the Prospectors and Developers Association of Canada (PDAC).The joint meeting also featured two trade exhibitions and more than 150speakers. PDAC’s trade show attracted about 400 exhibitors and an additional 200 in the concurrent Investors’ Exchange. CIM’s exhibition attracted about 600 equipment and service companies.

Jan 1, 2000

By Steven Hoerger

Newmont Mining has a large, integrated gold-mining operation in northern Nevada with several mines, stockpiles and processing facilities. There are more than 90 defined metallurgical ore types and more than 60 defined gold-recovery process options. Newmont developed a mine plan and process model to take better advantage of the available synergies at its Nevada mines. This plan includes a mixed integer and linear programming optimization tool. This system is maintained and operated by a Nevada planning group. Standard in-house planning software tools and methods have been implemented at all mine sites. These changes have allowed a reduction in mine engineering staff and have increased the effectiveness of mine planning.

Jan 1, 1999

By J. F. Barkley

Smoke abatement is a subject of which fuel technology, although absolutely essential, is only a part. Its successful accomplishment starts and ends with human factors that must be given thorough consideration; between this "start" and "end" fuel technology is applied. Smoke abatement usually starts from the desire of some person or persons to be free from uncleanness caused by the stack of someone else and ends with the sincere desire of the operator of the fuel-burning equipment to maintain a clear stack. Although "smoke abatement been discussed for many years, it is only recently that the public has been mindful of such expressions as "air pollution" and "air hygiene." The subject has duel in common with that of supplying pure water but is more complicated. The public desires pure water, expects pure water, is willing to pay for pure water, and expects to continue to pay for it indefinitely; it is a development of civilization. It is doubtless correct to say, however, that people in general do not et realize the detriment of air pollution to their well-being or give the question enough serious consideration. This is illustrated by the fact that in city smoke abatement it is the mass of small householders that sins the most and is the hardest to handle. It is rather difficult to assemble a group of people in a room without the air becoming contaminated with smoke. Smoke abatement will lag with the lack of desire for pure air - probably the biggest human factor involved in its accomplishment.

Jan 1, 1939

By M Shaffer, D C. Grant, D J. Goudie, P Sylvester, C Voisey

Scanning electron microscope–Mineral Liberation Analyser SEM-MLA can be used to discriminate between hematite/magnetite in iron ores, but achieving backscattered electron (BSE) segmentation between the two minerals is difficult for particles =75 µm using typical preparation and analysis methods for the MLA based on a tungsten filament SEM (Quanta 400) with 25 kV high voltage. Preparing iron ore sample mounts using a slow-speed polishing method, and conducting the experiment on a field emission gun SEM-MLA (Quanta 650) with the high voltage (HV) setting lowered to 15 kV reduces instrument noise and results in very clean BSE images and segmentation. This method requires new X-ray standards to be acquired for each mineral identity at 15 kV because of major changes in the spectra at lower kV. However, once these X-rays are added to the mineral reference list, effective segmentation can be achieved and a proper analysis obtained.CITATION:Grant, D C, Goudie, D J, Voisey, C, Shaffer, M and Sylvester, P, 2017. Discriminating hematite/magnetite via scanning electron microscope–mineral liberation analyser in the - mesh size fraction of iron ores, in Proceedings Iron Ore 2017, pp 541–548 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Van Dusen M

The involvement of concerned parties in all aspects of the Lihir Project from an early stage has promoted good relations between all groups. Activities involving landowners, the Lihir community, the New Ireland Provincial Government (NIPG) and the prospective developer include the Lihir Liaison Committee, Lihir Working Group, Environmental Planning Committee, Provincial Mining Task Force and the Lihir Mining Area Landowners Association (LMALA). With modifications, the Lihir Liaison model may be of use in promoting good relationships among parties in other mineral developments.

Jan 1, 1991

The modern Golden Cross mine entered the production phase in January 1992. The project is designed to produce over 100 000 oz/yr of gold and over 300 000 oz/yr of silver during a mine life of eight years. An open pit and an underground mine are operated producing around 850 000 t/yr of ore, to feed a conventional carbon-in-leach processing plant. Golden Cross is owned in joint venture by Coeur Gold New Zealand Limited (80%) and Viking Mining Company Limited (20 %).   Since the start of production several major aspects of the design have altered. The underground mine began as a mechanised cut and fill operation. The cut and fill stoping progresses in 3.3 m flatback lifts with maximum stoping width of 6 m. Where the ore zone is wider than 6 m a post pillar cut and fill method is used. In 1993 a new bench mining plan was introduced between the 270 and 260 levels. Flatbacking continued in the footwall drives in anticipation of variability of the ore width and orientation. The development of levels below the main service 200 level has indicated a possibility of bulk mining the ore block rather than flatbacks. This could lower mining costs but also introduce higher dilution rates. Development is in the advanced stages for trialing this method.

Jan 1, 1994

By C. Kloppers

The aim of this investigation was to reduce the cost of primary steel de-oxidation by substitution of aluminium primary de-oxidation with a practice that uses carbon. The cost of carbon is four times lower than that of aluminium. The application of carbon would directly result in raw material cost savings. Investigations were conducted at Iscor?s Newcastle steel plant on various steel grades. Specific production aspects were emphasized to ensure that the cost savings accrued would not create secondary expenses. These production aspects entailed: ?Yields on de-oxidation elements ?De-oxidation capabilities ?Alloying yields (Mn and Si) ?Carbon-pickup ?Nitrogen-pickup ?Temperature loss during tap ?Steel cleanliness ?Slag morphology. This project proved that carbon de-oxidation, apart from reducing de-oxidation raw material cost due to cheaper raw materials being used and lower consumption rates, resulted in steel that is cleaner and has lower nitrogen concentrations. Carbon primary de-oxidation has been implemented at Iscor?s Newcastle plant on a large range of steel grades, ranging from ultra-high carbon (> 0.60% C) to ultra-low carbon (< 0.03% C) grades. A net saving of between R100 000 and R200 000 per month was achieved.

Jan 1, 2001

By A. Feather

The Minataur? Process (Mintek Alternative Technology for Au Refining) is a novel route for the production of high-purity gold using solvent extraction. Following the successful demonstration of the process on a pilot-plant scale, a full-scale 24 t/a production plant has been commissioned at Harmony Gold Mine in Virginia, Free State. The commercial implementation of this process represents not only a significant advance in gold-refining technology, but may be instrumental in initiating important changes in the legislation regulating the marketing of gold in South Africa. Gold of either 99.99% or 99.999% purity can be produced from intermediate process products having a wide range of gold contents. The process comprises oxidative leaching of the solid feed, followed by selective solvent extraction of the gold from the leach liquor to reject impurities, and precipitation of high-purity gold powder. This paper outlines the process, presents selected results of two pilot-plant trials in which 5 kg/d of high-purity gold was produced from silver-refining anode slime and gold-electrowinning cathode sludge, and provides some details of the cost benefits.

Jan 1, 1997

Editor’s note: As usual, the June issue features an industrial minerals review. And some thanks are in order. Thank you to the industrial minerals annual-review editor, to the technical committees chair and vice chairs and to the authors of the individual commodity profiles. Jim Norman of GeoTrans Inc. is the industrial minerals annual-review editor. William Langer, U.S. Geological Survey, is the chair of the SME industrial minerals technical committees and the vice chair of the technical committee for construction materials. Other technical committee vice chairs include: •Lucy McCartan, U.S. Geological Survey, agricultural minerals. •Steve Herron, Oglebay Norton Performance Minerals, ceramics and refractory materials. •Srinivas Veeramasuneni, U.S. Gypsum, chemical raw materials. •Ismail Yildirim, Imerys, fillers and pigments. •Charles Landis, BPM Minerals, sorbents, filters and process aids. •Ray Harris, Wyoming Geological Survey, specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of the readers, the editors thank them

Jan 1, 2004

By Peter Bigwood

Whether drilling through tough clay or breaking rock, or facing the most severe conditions including mixed face ground, perched water and running and flowing sands, working under-ground certainly comes with no shortage of challenges. In an environment where the unknown is faced on a daily basis, tunneling contractors must be able to rely on their equipment to get the job done properly. Not only that, their equipment must comply with two of the highest priorities: safety and efficiency. In addition to being the number one concern, a proven safety record provides additional benefits to a company. A safe work environment serves as a key component to company growth, including the ability to remain competitive in bidding and maintaining higher-level, more challenging projects.

Jan 1, 2012

By Jeremy Morris

The city of Indianapolis has more than 25,000 homes currently on septic systems. Many of these systems do not function well because of their age and surrounding soil conditions. As Indianapolis has worked to eliminate septic systems and install sanitary sewers in large unsewered areas on the north-west side, capacity of the existing Belmont North Interceptor (BNI) became a concern. The BNI system currently services an area of approximately 80 km2 (31 sq miles) located within the northwest quadrant of the city (Fig. 1). Monitoring of the existing interceptor indicated portions of the sys-tem flowing half- to two-thirds full during dry weather conditions and surcharging during some wet weather conditions. Further analysis of the BNI based on growth projections coupled with increased sewershed yield resulting from the city?s septic tank elimination program (STEP) indicated dry-weather flows could potentially triple over the next 20 years. Based on these modeling results and current wet weather capacity issues, the city determined further STEP projects could not be performed within the BNI service area until

Jan 1, 2011

By J. F. Brune

This paper analyzes the explosion hazard resulting from the formation of methane-air mixtures in the mined-out gobs of underground longwall coal mines. Although direct examinations of the gob atmosphere are difficult due to the inaccessibility of these gobs, evidence from methane drainage practices and investigations of numerous mine explosions suggests that explosive methane zones can form within longwall gobs. Explosions and fires resulting from these methane accumulations have led to severe and fatal injuries to the miners. Most recently, this was demonstrated in the explosion of the Upper Big Branch Mine in West Virginia, where 29 miners lost their lives.The paper also reviews current research on numerical modeling of gas flows in longwall gobs and outlines how targeted injection of nitrogen into gobs can effectively reduce the volume of such explosive methane zones. The paper concludes that comprehensive monitoring of gas compositions, along the accessible fringes of the gobs along with inertization, improved ventilation schemes and further research are necessary to control this explosion hazard and make mining operations safe.

Jan 1, 2013

By Christoph Broeckmann, Andrew Gardula

"The adoption of high-pressure grinding throughout the cement industry has yielded enormous savings in energy and wear material costs. There are also a number of installations, which are applied in iron ore and kimberlite processing operations. High pressure grinding offers the same potential for energy and media savings, as well as opportunities for improved, downstream metallurgical performance, in hard rock mineral processing. This paper focuses on developments in machine design and wear surface engineering for high-pressure grinding of the hard rock ores in the mineral processing industry.INTRODUCTIONIn the early eighties 3.4 % of the world electric energy was consumed for crushing and grinding operations of minerals and 0.6 % in the ore dressing industry. During that time using a laboratory press Prof. Schönert found that interparticle comminution at high pressure requires remarkably less energy as conventional grinding technologies. In grinding of cement clinker he expected energy savings between 33 and 50 % compared to ball mills [1]. Piston presses are limited in throughput. Thus, the principle of interparticle comminution was adapted by the use of high pressure grinding rolls (HPGR) to a continuous plant process. Figure 1 shows the main components of a roller press: The roller nip of width s is formed between the floating roller (1) and the fixed roller (2). The diameter of the rolls will be denoted with D, the width with B. The total press force F can be adjusted using a hydraulic system with two or four pistons (3). In order to compare machines with different roll geometries the specific pressing force p is introduced:"

Jan 1, 2005

By I. D. Nock, R. M. Parkin

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993 (original title: Knowledge-based condition monitoring of cone crushers). A large proportion of the electricity used by the quarrying industry is consumed in the comminution and sizing process. In most cases aggregate processing plants operate with minimum control features resulting in limited operational efficiency. Improved control is required to increase operational efficiency with concomitant savings associated with reduction in re-circulating load and improved resource utilisation. Development work has suggested that a combination of adaptive control and process condition monitoring could improve control of comminution plants. Many commercial process control and condition monitoring systems are available, but none were deemed suitable due to the domain specific characteristics of the application. An assessment of the particular characteristics of cone crushing concluded that the application was best suited to the use of small domain specific process control combined with bespoke condition monitoring. The processing power of the control system for the project is a function not of the academic requirement, but rather the economic and practical constraints imposed by the application. As a result of the constraints a high-end PC system has been designed in preference to a workstation. Within the research project work packages are sub-divided into novel wear sensor development, knowledge based control/condition monitoring and the investigation and mathematical modelling of the wear mechanisms inherent in cone crushing. Numerous strategies were considered to implement the control system outlined. The system currently under development is a modular design which utilises intelligent novel sensors to provide a variety of data inputs

Apr 1, 1994

By Michael I. Brittan, Craig M. Sams

"Economies of scale and the variable characteristics of many large ore deposits have resulted in grinding installations using very large SAG mills fitted with variable speed drives. Low-aspectratio single-stage SAG mills were introduced in South Africa to process the consistent gold bearing Witwatersrand quartzites. Elsewhere, circuits were patterned after the more conventional North American circuits with high-aspect-ratio SAG mills followed by ball mills. This paper provides information on two recent Gold Fields group installations covering both types of SAG mill in large, single-stage applications. While these operations process similar tonnages, the mills represent opposite ends of the aspect-ratio spectrum. The Tarkwa mine in Ghana employs a low-aspect 27’ x 42’ 14MW SAG mill. The St Ives mine in Australia operates a conventional 36’ x 18’ 13.4MW SAG mill.INTRODUCTIONGold Fields is one of the world’s largest gold producers with annual production of approximately 4.2 million ounces. The Gold Fields group has operations in South Africa, Ghana and Australia, along with numerous exploration sites and advanced projects in several other countries. This paper discusses new milling operations in Ghana and Australia.TarkwaThe Tarkwa Gold Mine is located in Ghana, West Africa, approximately 350 kilometers west of the capital city of Accra (Figures 1 and 2). The site conditions are tropical with an average annual rainfall of 1,930 mm and a maximum temperature of around 35°C."

Jan 1, 2006

THE flotation plant at Mount Lyell was erected, primarily, for the treatment of ore from the Lyell Comstock mine. These workings are situated over a mile in a direct line north of the North Mount Lyell mine, and are connected with the Reduction Work at Queenstown by a 2-ft. gauge steel tramway via the Queen River valley a distance of 7 miles. The property was purchased from the Mount Lyell Comstock Copper Co. After the disastrous fire in the North Mount Lyell mine in October, 1912, steps were immediately taken to make Lyell Comstock ore available for treatment, in order to relieve distress caused by any prolonged stoppage of work, and subsequently 13,032 tons of ore, averaging 3.38 %copper, 0.28 oz. silver, and 0.034 oz. gold; were smelted. When operations were resumed at the North Mount Lyell mine, it was evident that there was no economic advantage in smelting Lyell Comstock ore as compared with the higher value North Mount Lyell ore, which was also a better flux for the Mount Lyell pyrites, and that the future of the Lyell Comstock ore depended upon cheap mining and successful concentration of the ore. Therefore, extensive trenching and diamond-drilling was carried out, and a sufficiently large quantity of ore proved available for cheap extraction by open-cut methods. At the same time bulk tests by flotation were carried out at the Minerals Separation testing plant in Melbourne on different classes of ore from the Mount Lyell Comstock mine proper, followed by laboratory tests at Queenstown on all classes of ore available. All these tests demonstrated that the ore was amenable to the process, provided that it was ground finely enough. Plant erection was delayed by the general dislocation of business at the outbreak of war, but finally it became...

Jan 1, 1920

By Lulie H. Crump

Salient information on reserves, production, and consumption of fuels and energy by State are summarized in this Bureau of Mines publication. The data are broken down by fossil fuels (coal, petroleum, and natural gas) and hydropower and nuclear for the major consuming sectors: Household-Commercial, Industrial, Transportation, Electric Power and Miscellaneous. In addition, total energy consumption in the Nation in 1972 is compared with consumption in 1971 and 1973 (preliminary data).

Jan 1, 1974

By Pupazzoni P. D, Meissner D. C

Incorporating an iron ore pelletising plant, a MIDREX&apos;"&apos; Direct Reduction Plant, and a mini mill, the conversion of iron ore fines to high- quality steel slabs in Western Australia is among the lowest cost routes in the world. The cost and availability of iron ore and natural gas, government support, and proximity to the growing Southeast Asian market all contribute to the competitive position of the area. Owing to the lead-time required, this is an ideal time to develop a new project to supply semi-finished steel to Asia for rolling to a finished product. A project contracted now will start up in about three years, when the market should have recovered.

Jan 1, 1999

As the 2009 George Fox Conference neared its conclusion, Arthur Silber, project chief of the Mass Transit Tunnel (MTT) project was able to pull away from the constant buzzing of his Blackberry long enough to give a short presentation and a significant piece of news to the record 318 attendees at the Graduate Center, City University of New York regarding the MTT project. ?As the former administration (The Bush administration) was leaving office, we were told that Congress was notified of the FTA?a (Federal Transit Authority?s) intent to issue final design construction approval to us,? Silber said of recent advancements concerning the $7.2-billion dollar project. It will add passenger rail service from New Jersey to New York City as part of the Access to the Region?s Core project in the form of the Trans Hudson Express Tunnel (THE tunnel). ?That 10-day waiting period ended yesterday (Jan. 26).? In days leading up the Fox Conference, those involved in the tunneling industry, and the MTT in particular, had a lot to be optimistic about. The MTT received environ-mental approval on Jan. 14 (see page 9) and, with the acceptance of the final design, the multi-billion dollar project moved that much closer to a ground-breaking ceremony. So close, in fact, that before leaving his office for the conference, Silber posted the contract documents and plans for the Manhattan Tunnel project online at www.arctunnel.com (an indepth look at the project from Silber is on page 22). While many were interested in the progress of the project, Silber also spoke about the new plans for the cavern complex at the New York Penn Station expansion. The original plans called for two lines that would come into a large cavern complex with a north and south cavern to access the trains. After numerous core samples were taken from the streets of Manhattan, it was deter-mined that this design was not feasible and changes were made that will include a deeper cavern under Sixth Avenue, with 14-m (45-ft) of cover with a 30-m (96-ft) wide cavern that resides entirely under 34th Street. The cavern was also moved 20 m (60 ft) to the west to remain at least 61 m (200 ft) away from New York City Water Tunnel #1. The new design will include three-over-three track arrangement. The mezzanine will be 46 m (150 ft) below street level at 8th Ave, Silber said.

Jan 1, 2009