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By J. J. Davis, C. A. J. Fletcher, M. Li, T. Jancar

This paper summarises the experimental approach to spiral modelling at the Julius Kruttschnitt Mineral Research Centre, University of Queensland, involving the use of plastic density tracers to determine partitioning performance on three models of coal spiral. This work has led to phenomenological models of the three spiral profiles most widely used in the Australian coal industry. The results from a parallel computational fluid dynamics approach to spiral modelling currently underway at the University of New South Wales are also presented. The computational simulation has been successfully applied to generic spiral geometries and is capable of predicting the fluid phase three dimensional flow fields and corresponding free surface profiles for moderate Reynolds' number and Froude numbers. Simulation predictions are compared with experimental results from a Mineral Deposits LD9 coal spiral.

Jan 1, 1995

By F. Bourgeois, J. A. Herbst, R. P. King

The ultrafast load cell (UFLC) has proved to be an exceptionally good device for the study of the fundamental processes associated with the impact fracture of particulate material. A new high- sensitivity UFLC has been commissioned at the Utah Comminution Center for the study of low-impact energy single-particle fracture. The force-time histories of individual fracture events have been measured. The force and energy absorbed at crack initiation have been measured at several particle sizes. The mass specific energy for fracture and the associated breakage function have been determined. The distributions of particle breakage energy and particle strength have been measured as a function of particle size.

Jan 1, 1992

By Felicia F. Peng, Victor Z. Sun, Syd S. Peng

A probability-based analysis method in conjunction with the finite element structure modeling technique to evaluate an entry system stability is developed. Variability of the rock properties and loading surrounding the entry system is taken into consideration to predict a roof stability by using the probability of failure instead of the common safety factor concept. A dynamic programming is applied to establish a recurrence relationship between the degree of potential roof fall and accumulated roof fall index in an area of interested. A probable distribution of roof fall is assessed by using a developed computer program, RFSTAB. The assessment of the roof falling boundary in the longwall entry system is used as the example to illustrate the procedure and effectiveness of this analysis method

Jan 1, 1996

By Dominigue Francois-Bongarcon

This paper presents a step by step vulgarized review of the applications of geostatistics to the estimation of the mineable, recoverable reserves of the Cinola gold deposit in British Columbia.

Jan 1, 1988

By K. D. Allen, M. J. Blattman

The problem of measuring the amount of rock removed during a given time interval is faced by most mining operations. Many methods have been developed with varying degrees of success, dependent upon the mining method and the availability of usable data. The Rosebud Mine has been in production for nearly two years, employing several techniques to estimate monthly production from underground production stopes. The use of three-dimensional solids generated from survey data has greatly improved the reliability and confidence of monthly production reports. The authors will summarize the methodology currently being utilized at Rosebud.

Jan 1, 1999

By Dennis K. Mortensen

Improvements in metallurgical performance are continually being made in the attempt to achieve the metallurgist's goal of maximum concentration, minimal loss of recovery and at costs that maximize profit margins. Innovative technological advances provide a means for the metallurgist to more thoroughly understand the mechanisms of separation and foster new ideas from old. Problems associated with the implementation of new technology can be overcome effectively if the metallurgist thoroughly understands the metallurgical systems with which he is working.

Jan 1, 1991

By H. J. M. Rose

Arising out of the world energy crisis and the increasing demand for nuclear fuels, the Elliot Lake operation of Denison Mines Limited is currently expanding its facilities to meet its increased contractual obligations of some 90,500,000 kg of uranium oxide between now and the year 2011. The mining of uranium is subjected to increasingly stringent environmental controls by governmental and associated agencies so as to safeguard the health of the employees. A heavy burden of responsibility is thus placed on the Ventilation Department to ensure, through efficient planning and good control, that satisfactory ventilation conditions prevail throughout the entire operation. Management realized at the outset of the present phase of this expansion, that the establishment of a properly organized and administered Ventilation Department would be essential to ensure that long term production goals are achieved within the numerous constraints imposed by existing legislation. The paper describes the formation of the department by recruiting technically competent, but largely inexperienced, ventilation personnel, their practical training programme, the departmental structure and the operational and control responsibilities of the ventilation staff.

Jan 1, 1980

By Pradip

The development of highly selective mineral processing reagents, which are not merely metal-ion specific, but specific to the particular mineral surface structure, is essential for the exploitation of relatively more difficult-to-process ore deposits, in particular for the separation amongst minerals having the same constituent ion. Both the choice of the functional group as well as the molecular architecture of the reagent determine its selectivity. Several examples are presented in this paper to illustrate the concepts of structure specificity and molecular recognition at mineral surfaces - the concepts crucial to the advancement of the emerging science of reagents design. Recent advances made in the understanding of molecular interactions involved in the synthesis of biomineralized materials are discussed so as to delineate the utility of this approach in the design of selective reagents for mineral separation.

Jan 1, 1994

By S. K. Kawatra, S. J. Ripke

Iron ore pellets use bentonite clay as binder at dosages from 0.5to 1.0% (10 to 20 pounds per ton) of moist iron ore concentrate. Bentonite is typically shipped hundreds of miles from Wyoming to the Lake Superior iron ore district. It is therefore best to know how effective a bentonite will be before it is shipped and used to bind concentrate into pellets. Current tests of bentonite effectiveness include: plate water absorption, methylene blue uptake, free swell, exchangeable cations, and glycolated layer expansion. However, these tests have many disadvantages: First, they only measure the ability of a bentonite to expand, disperse, or absorb, not how well it will bond. Second, most of the tests require up to 20 hours to perform. Bentonite only has a few minutes to interact within the concentrate before it is indurated (sintered). These long-term tests may not reflect the true behavior of bentonite. Third, the tests are tedious and often results are inconsistent between different iron ore concentrates, labs, and technicians. Fourth, some of the testing equipment is difficult to procure. Fifth, procedures are often difficult to standardize. In this paper, the Binder Effectiveness Strength (BESt) test to evaluate binders for iron ore pellets is presented that: measures the ability of bentonite to bond, requires only about two hours to complete, is simple and reproducible, and utilizes readily available equipment that has been standardized for decades.

Jan 1, 2003

By R. Mohr

Storm water runoff from mine facilities such as haul roads, waste disposal sites and ore bodies have become recognized as the primary facilities associated with non-point source drainage. Depending on the ore body, facility design and geographical setting, nonpoint source drainage can cause pollution impacts to local surface and ground water resources. Non-point source impacts from surface mine drainage have become an important regulatory issue for the mining industry. Implementing non-point source drainage control plans that prevent impacts to water resources can be accomplished cost-effectively with moderate labor requirements. Design considerations for plan development must incorporate parameters including contributing drainage area size, slope, flow velocity, vegetation characteristics and soil scour velocities. The success of non-point source drainage and erosion stabilization planning is based on implementing control measures that dissect drainage patterns, reduce flow velocities and disperse runoff towards sediment control sites. Interim and long-range drainage control measures should begin during exploration activities. Regulatory legislation addressing non-point source pollution sources was enacted as amendments to the Clean Water Act (CWA) in February 1987. The legislation required states to initiate non-point source pollution control programs.

Jan 1, 1991

By R. P. King, M. K. McCarter, K. S. Free

Mine plans typically consider the profits and costs associated with extracting and processing minerals into marketable products. Interrelationships between mine and mill costs are often overlooked during the process of mine plan optimization. A simple and quick method for predicting milling costs for a given block would improve the planning process, especially if the procedure could be incorporated as part of routine ore grade analysis of drill core or cuttings. Incorporating milling costs as part of the mine planning process could improve overall optimization of the mine/mill combination. A method developed by the Utah Comminution Center (UCC) at the University of Utah provides a possible answer to the need for quick and reliable grinding cost estimation (King et al., 1996). Using results from single-particle impact tests, a work index, called the Utah Load Cell Work Index (ULCWI), is calculated. The potential for routine use of the new method is explored by comparing ULCWI values with corresponding Bond Work Index (BWI) values for eight mineral materials (Free, 2000).

Jan 1, 2004

By M. S. Duffy

To exploit the mineral resources of fine grained ore bodies the minerals processing industry is turning to fine grinding technology, of which tower milling has become an established part. However, compared to other mills relatively little is known about the operating mechanisms in tower mills. In all milling processes one of the keys to understanding how they work is in knowing how their grinding media move. To investigate the ball motion in tower mills a glass unit was therefore constructed and measurements taken of the movement of the grinding media. This paper describes the results from this study.

Jan 1, 1998

By T. N. Moore, E. M. De Souza

Because jackleg rock drills are a potential source of hand vibration exposure, they can effectively produce Hand Arm Vibration (HAV) Syndrome in their operators. This will affect operator efficiency and mine productivity. As a result, a significant amount of work has focused on redesigning rock drill handles using new materials to minimize hand-transmitted vibration. In previous work developed by the authors (1991), a detailed study was undertaken to determine the effectiveness of using elastomer covered handles in place of the standard steel design. The results indicated that, for an elastomer-based handle design, the overall acceleration level experienced by the hand can be reduced by as much as a factor of three, relative to the steel handle. It was also shown that this reduction takes place predominantly in the frequency range above 500 Hz. This paper presents an investigation of the long-term effectiveness of an elastomer-cushioned handle under different conditions underground. In this study, sponsored by the Mining Industry Research Organization of Canada (MIROC), a number of cushioned handles were quantitatively and qualitatively tested in five operating mines. The vibration testing program has indicated that the cushioned handle can reduce overall vibration levels by as much as a factor of three. The qualitative assessment program of the cushioned handles by the drill operators has indicated some degree of preference for the cushioned handles over the steel handles, if certain design modifications are performed. This research program indicated that cushioned handles have the potential to become the dominant method with regard to vibration reduction and operator performance.

Jan 1, 1994

By Edmond O’Donovan

Mooranbah North is a new greenfield project in Australia's Bowen Basin that is projected to produce 4 mtpa of hard coking coal from a single longwall. Located in Central Queensland in Australia's northeast, this is one of Australia's main coal producing regions. From the outset, Mooranbah North's approach to equipment selection has differed markedly from that usually taken in the mining industry, and the conveyor industry in particular. Until recently, no performance requirements have been placed on conveyor equipment suppliers. This arose from a practice of purchasing components in an ad-hoc manner from a variety of sources, and the mine then configuring the system. More recently, single source supply has been adopted as a means of obtaining some performance guarantee, usually expressed in terms of system availability. Unfortunately, the term "availability" has a multitude of definitions, particularly in the underground coal sector. A conveyor availability of 98% is a common goal but this rarely means the conveyor must operate 165 hours/week, 52 weeks/year. There are mines that have one maintenance shift for each production shift and claim availability of 100%. What is meant is that no down time is logged to the conveyor during the hours that it is wanted. This "generous" definition of availability would not be tolerated in many industries and nor should it. Unfortunately, a true definition of availability, such as is applied to steam turbines in the power generation industry, is not particularly helpful. Five day/ week operations would immediately face a 28% penalty against 7 day rosters, and there would be no sensible manner in which weekend maintenance could be incorporated into the availability formula. The approach adopted by Mooranbah North was to specify a period of "Failure Free Operation," which would be followed by a maintenance period. This

Jan 1, 1998

By B. Suresh, Kalyan K. Das, Pradip

A series of salicylaldoxime derivatives with alkyl group substitution in the main chain and the side chain were synthesized and evaluated for the flotation of malachite, cerussite and smithsonite. The effect of chain length and the position of the substituent group on the selectivity of separation amongst oxidized copper, lead and zinc minerals are discussed in this paper.

Jan 1, 1995

By R. W. Smith, A. Raichur, M. Misra, I. A. H. Schneider

The concept of microorganisms as chemical reagents (flocculants, flotation modifiers and flotation collectors) is quite new. Potential uses for microorganisms include their use in place of certain conventional flotation reagents and as flocculating agents in minerals engineering processes. In addition, in some studies micro-organisms have been used to modify mineral surfaces and, thus, the flotation or flocculation of the minerals.

Jan 1, 1995

By A. V. Glembotsky, N. A. Greshnova, V. P. Seregin, V. A. Glinkin

Based on a new alternative depressant of zinc sulphide - dimethyldithiocarbamate- modern technology has been developed for the treatment of complex polymetallic ores. In addition to its general function (depression of sphalerite and iron sulphides to some extent), this double-acting reagent is a promoter for galena and silver minerals. Laboratory and plant tests, as well as industrial experience have all shown consistently higher silver recovery to the lead concentrate as compared with sodium cyanide, resulting in less pollution and a safer environment

Jan 1, 1995

By D. S. Bloswick

An investigation an4 analysis of slip/fall accidents specifically pertaining to underground coal mines was conducted. From a population of 751 accident reports, three major sources of injury which account for over 80% of the incidents have been identified. The specifics of this study are presented in this paper. Based on the results, several recommendations are made to reduce such accidents in underground mines. In addition, a brief discussion of the slip-hazard analysis laboratory at the University of Utah, which will be useful in future analyses of these accidents is presented. Work in this facility includes the simulation of certain mining activities in a controlled setting. Foot forces are measured and work methods subsequently developed to minimize the slip potential of these activities.

Jan 1, 1988

By E. Turner

In a joint exercise, the European Commission, (led by DG Enterprise), the EU Member States, the various sectors of the Extractive Industry, and WWF have developed a set of Sustainable Development Indicators specific to the non-energy extractive industries. Of equal significance, a Voluntary Scheme for publicly reporting the data has been created. This paper presents these indicators at the company level and explains the role of companies and trade federations in establishing the reporting process. This has been achieved in just 18 months and the paper identifies 6 Success Factors, which have made this possible. It is believed this is the first Scheme of its kind to be put into place and to have begun operation. It is a model for co-operation between government, the NGO sector and industry. The first set of data, based on the reference year 2001, has been gathered. The SD performances of the European Minerals Industry will be publicly reported on for the first time, on the basis of these 2001 data by industry sub-sector. The Member State level Indicators will follow to complete the picture.

Jan 1, 2003

By J. C. Emerick

Preliminary investigations have shown that wetland-based treatment systems can be an effective and relatively inexpensive control strategy for mine drainage pollution in eastern coal mining regions. This strategy also has potential for western mining regions, although too few systems have been installed in the west to permit general evaluation of the concept for western climates. The construction of prototype systems is encouraged for some situations. Wet-land environments have the capability of removing metals by natural geochemical and biological processes, including precipitation, filtration, ion absorption, and biological uptake and accumulation. Data presented for natural wetlands receiving mine drainage show removal of iron and other metals, and high accumulation of metals in soils and plants.

Jan 1, 1988