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By J. G. Groppo

A beneficiation process has been developed to provide selective separation of unburned carbon from high loss-of-ignition (LOI)fly ash. Using froth flotation to achieve selective separations requires long residence times and high reagent costs. A proprietary reagent system has been developed to address these limitations. Based on the results obtained from laboratory and pilot-scale investigations, a flowsheet design has been developed to produce two distinct usable products from class F fly ash — low LOI ash and a high-carbon product suit-able for reburning or further upgrading.

Jan 1, 1996

By T. Wisdom, D. Romo, G. Seale, R. Jansen

Thickening remains relatively misunderstood since it is typically near the end of the process and not directly involved in metal recovery. When operating well, thickeners are ignored and left to run independently, the ‘out of sight, out of mind’ phenomena. However, when operating poorly, there is a lack of basic understanding and remedial actions to solve issues are reactionary rather than proactively addressing shortcomings. This series of papers breaks down in sequential order the stepped phases required to gain an appreciation and thorough understanding of the science behind thickeners, and key thickener components, and basic troubleshooting skills. This second paper starts with identifying the different approaches to thickener test work including static and dynamic settling tests followed by high-rate versus paste thickening. Complimentary to test work, the mechanisms surrounding coagulation and flocculation are presented and explained. The basic mechanisms for coagulation and flocculation are discussed to support the different test work approaches and provide the reader with the basic background.

Mar 2, 2022

By Rajive Ganguli

There are several elements of online pedagogy and information technology that are being used in the University of Alaska Fairbanks’(UAF) course “ES 201: Computer Techniques,” to enhance classroom teaching. The use of information technology in this class grew from a desire to make lecture notes available to students. This has grown to include a sophisticated, online delivery software package. It provides chat rooms, discussion groups, and online testing and grading. Online delivery aside, the class uses the telnet, e-mail and C++/FOR-TRAN compiler facilities of the university server during class to enhance learning. During class, for example, the students read the lecture notes on the Web browser, telnet to their university Unix accounts, check their e-mail and download programs (to be covered in class) sent by me, and then compile, run and modify the programs. The class, therefore, requires students to be active most of the time. This ensures their full attention and better learning due to the hands-on experience (Fig. 1).

Jan 1, 2000

By Russell J. Sheets

Reactivation of highwall slope failures during adverse weather had intermittently impacted haul road access into a previously mined open pit. These impacts ranged from limited access to full closures; however, the greater impact was to an underground mine that was developed within the open pit. Following several significant precipitation events, a rapid snow melts greatly accelerated movements finally closing the haul road and destabilizing other past failures. In addition to re-designing the overall pit access, the decision was made to relocate the primary portal to a more stable highwall. An accelerated surface geotechnical review was required to advance the portal relocation; however, only existing information from past investigation, existing geology model, visual inspections, and slope monitoring data were available for the assessment - no new investigations or data collection could be completed within the allowable timeframe. The evaluation included a review of the geology, an assessment of the current highwall condition and previously observed performance, and a rockfall analysis to evaluate existing catchment above the proposed new portal location.

Feb 1, 2024

Maximising margins in competitive markets demands superior productivity. Unfortunately, management systems developed early this century for other industries often drive counterproductive behaviours choking mining productivity. Many executives and managers waste valuable time and effort relying on simply training and communicating to improve managerial practices and attitudes. In covering practical human behaviour, the paper explains why this fails - and explains how to use systems to successfully drive improved managerial practices and attitudes. It highlights use of modern performance Measurement, Analysis and Reporting systems to drive behaviours and improve margins - without capital investment - and make executive and managerial work easier and more effective.

Jan 1, 1999

By Graham A. Mathieson

The precise definition of an ultimate or economic pit has, over the years, received much attention in the literature on the subject of mine planning. Unfortunately, relatively little has been published in the area of pit sequencing and scheduling--an aspect which is typically of much greater economic significance both during the life of a mining operation, as well as in the evaluation of an exploration project. This paper discusses an overall mine planning methodology with emphasis on the design of an optimal sequence of pit expansions or phases. Although the concepts given are not new, it is hoped that some practical suggestions will be made. The paper will also describe graphical techniques which have been found useful in comparing the merits and impacts of alternate planning strategies and production schedules.

Jan 1, 1982

By John G. Banker, Arthur L. Forrest

Titanium solves corrosion, maintenance and environmental problems in many reactor and autoclave applications. Titanium clad construction permits autoclave designers a great deal of flexibility combined with significant cost reduction. Titanium alloys can be selectively applied in specific regions of the auto­clave to accommodate local environmental conditions. Resistance to general corrosion, crevice corrosion, abrasion, and ignition conditions can be accomplished selectively and eco­nomically. Explosion clad pressure vessel fabrication and perfor­mance have been proven through three decades of experience.

Jan 1, 1996

By Bruce Hebblewhite

Australia’s Minerals Tertiary Education Council (MTEC) has achieved several successes during its first three years of operation. This initiative was developed through the Minerals Council of Australia, in conjunction with three partner universities involved in mining engineering education. The partner universities are the University of New South Wales (UNSW); Curtin University, the West Australian School of Mines (WASM); and the University of Queensland (UQ). The collaboration between these partner universities and industry has led to the development of shared course material, cross-institutional teaching arrangements, and the development of a number of flexible, distance-based delivery programs. This article then discusses future initiatives. Importantly, the challenge is the future initiative planned to cement this collaboration by the formation of a “virtual” national school of mining engineering: Mining Education Australia (MEA). This will provide a common third and fourth year program to all three universities beginning in 2007. The common program will involve innovative teaching and learning arrangements, greater student exchange potential and a more significant input by industry into the education process.

Jan 1, 2006

Following a disaster in a mine, it is important to understand the state of the mine damage immediately with limited information. Computational fluid dynamics can be used to simulate and ascertain information about the state of ventilation controls inside a mine. This paper describes a simulation of tracer gas distribution in an experimental mine with the ventilation controls in various states. Tracer gas measurements were taken in the lab experimental apparatus, and used to validate the numerical model. The distribution of the tracer gas, together with the ventilation status, was analyzed to understand how the damage to the ventilation system related to the distribution of tracer gases. This study will be used in future research in real mine measurements to compare collected and simulated profiles and determine whether damage to the ventilation system has been incurred during an emergency situation, the nature of the damage and the general location of the damage.

Jan 1, 2011

By Allan M. Hale

The central Florida phosphate industry is not a recent development. The first phosphate mining occurred in approximately 1888 (1). Many of the original mining companies were "wildcat" operations operated with rapid phosphate extraction as the sole purpose and no long-term commitment to development. Many of the early pioneers were ill-equipped to mine phosphate at either a practical or economical level; as a result many of these early companies "folded" after only a brief period of operation. However, as these early companies went out of business, several large companies developed, expanded their mining territories bought up the folding companies and by 1903 (little more than 10 years after the first mines were started), approximately 37 of the original 60 mines were control- led by three major companies (1). In the early period, mining reclamation was nonexistent. The mined out areas were left to revegetate and reclaim "naturally" over the period of many years. Reclamation practices were only started relatively recently and the various reclamation techniques developed and used in the past have continued to be employed with varying degrees of success through the present time. The reclamation techniques used in the past and currently include land and lakes restoration, sand tailing reclamation, slime ponds reclamation and overburden fill.

Jan 1, 1980

By Robert Moore Lewis

A unit for separating minerals into two prescribed size fractions, designated as a Lewis Hydrosizer, was developed at the North Carolina State University Minerals Research Laboratory. Ore samples with different mineral compositions, including coal, were separated effectively with the laboratory continuous unit. Commercial size units are in operation in North Carolina and Mexico, and under construction in Norway. Additional units are being build or are in the planning stage at several companies.

Jan 1, 1983

The paper describes a practical methodology based on numerical modelling for the prediction of progressive failure of underground mine stopes with cable bolt support. A case study of the 40-761 stope at Kidd Creek Mine, Timmins, Ontario is presented. The stope was mined by blasthole open stoping in 1986 as a lead stope within a mining block between 36-1 and 38-2 levels. Initially designed to peak at 38-2 level, the stope back caved upwards approximately 40m towards 36-1 level. Cable bolts were installed above the stope from 36-1 level after caving had begun. The stope eventually stopped to cave when the falling rock mass encountered a sufficiently high cable density. The paper provides details of the geomechanical data and modelling results of the case study. Numerical modelling is carried out using a finite element package known as e-z tools which has, among other things, a special cable/rockbolt simulation capability.

Jan 1, 1994

By R. L. Eppley

The Blacklick Creek Watershed Association was awarded a $158,000 Growing Greener grant from the Pennsylvania Department of Environmental Protection in 2002 for the design and construction of a sulfate reducing bioreactor (SRBR) cell to treat acidic discharge from the Judy 14 abandoned underground coal mine near Indiana, PA. The vertical flow SRBR was designed to treat 38 liters per minute of MIW containing elevated concentrations of aluminum and iron. Other treatment systems at this site plugged due to aluminum precipitates; this problem did not occur in the SRBR. The bioreactor has been periodically overloaded with flows up to six times the design rate. To date, the only maintenance performed on the unit has been the addition of hay to the surface of the unit in response to less than expected performance. The periodic hay additions appear to have restored the SRBR to nearly post-construction levels. Since construction, the SRBR has treated about 136,000 cubic meters (36 million US gallons) of MIW.

Jan 1, 2010

By G. Abramov

The 20th Century saw the modern mining industry enriched by one outstanding method of extracting of mineral resources called Borehole Mining (BHM). Mean while, despite its successful track record in wide ranging locales, few specialists are yet aware of this technology. The intent of this article is to introduce borehole mining to a wider spectrum of drilling and mining professionals. The BHM method is based on in-situ water jet cutting of rock mass. On Fig. 1 the schematic of the method is presented. The borehole mining tool 1 is lowered into the borehole 2 and high pressure water 3 is pumped down. At the bottom part of the tool, one portion of that water comes out through the hydromonitor nozzle 4 in a shape of water jet 5 and cuts the material 6 creating slurry 7. The other portion of high pressure water then comes to the hydroelevator 8 (jet pump, eductor) which produces a vacuum. When the slurry reaches this vacuum zone, the eductor sucks the slurry and pumps it up to the surface, where rock parts are separated from water in a tank 9 or a pond and clarified water is pumped down again closing the re-circulating BHM water supply system. The borehole mining tool is suspended on a drill rig tower 10 which allows the tool to rotate and move vertically along the borehole axis. While extracting rock mass, underground caverns (stopes) 11 are created. If necessary, compressed air 12 can be injected to the raising slurry flow to create an airlift effect. Also, a secondary agent 13 (such as oil, foam, etc.) can be added to the stope through the gap between the tool and the casing. As seen from the illustration, BHM is the remote mining method of extracting of mineral resources through boreholes by high pressure water jets.

Jan 1, 2001

By G. Labonte

The behavior of four different redox sensing electrodes (gold spiral, black platinum, chalcopyrite, and galena) during roughing and cleaning flotation is examined and related to the flotation response. Although it is difficult to provide unequivocal interpretations of the different potentials measured, the results indicate that the solution potential (as sensed by the black platinum electrode) is different from that of the pulp potential (gold spiral) and is only weakly related to the flotation response. On the other hand, the potentials exhibited by the gold spiral and the two mineral electrodes are related to the floatation response. The gold and mineral electrodes exhibit different transcient responses during the addition of flotation modifiers (e.g. NaCN, SO2). These responses appear to be related to the reactivity of the minerals and could indicate the conditioning time required to achieve flotation or depression of selected minerals.

Jan 1, 1989

By Alan Rhodes

This study is initiated to investigate the efficiency of separation of mineral slimes using electroflotation as compared to that of column and conventional flotation techniques. Important parameters such as collector concentration, pH, current density, aeration rate, etc., have been studied. The results indicate that electroflotation can be used more efficiently in processing rutile slimes (10 µ) under certain operating conditions.

Jan 1, 1982

By S. C. A. Franca, M. T. Millqvist, A. B. Luz

Laboratory experiments were performed on a Brazilian diatomite from Bahia State to produce an industrial product for use as a filter aid. Bench and pilot plant tests were conducted consisting of: diatomite desegregation, organic matter and clay removal, filtration, drying and calcination. Calcination temperature and sodium carbonate addition influenced diatomite particle size distribution. Optimum filtration rates for calcined products were obtained at 900°C and 47 min. residence time with 3% (w/w) of sodium carbonate addition, and resultant products met specifications imposed on filter aids.

Jan 1, 2002

By R. R. Klimpel

In three recent publications, Klimpel et al (1988) and Klimpel and Hansen (1988, 89), the theory and invention process behind the identification of two new classes of sulfide mineral collectors were summarized. These two new families can be represented by the 111 generalized formulate: R1-S-R1 -NRI III (denoted as the F-series chelation family) and R-S-R or R -CHSCH-R (denoted as the S-series redox family). The influence of systematic changes in the various R groupings on laboratory batch flotation cell tests has been covered in the above references and will not be repeated in this paper. In particular, the recent article by Klimpel and Hansen (1989) should be studied as a research introduction to this paper.

Jan 1, 1989

By Feng Junfa, Du Feng, Li Huamin, Syd S. Peng

"The Ordos coal field is located in the northern midwestern part of China (Fig. 1). Since the mid- 1980s, it has been developed into one of the major coal fields in the world, producing approximately 833 Mt (918 million st) of raw coal in 2013. There were once more than 400 coal mines operating in the region. However, due to the combination of market conditions and implementation of government consolidation policies, the number of coal mines operating in recent years has been reduced considerably, with increasing output.The surface of the Ordos coal field is covered with loess and alluvium layers of varying thicknesses. In many areas, their combined thickness may amount to as much as 100 m (328 ft) underlain by thin bedrock. Many loess and alluvium are aquifers receiving water from rainfalls. There are also gullies of varying depths crossing the coal field. Figure 2 is a typical stratigraphic column highlighting the coal seams and roof and floor rocks of interest.In conjunction with the development of highproductivity coal mines, numerous ground control instrumentation tests have been conducted in the operating longwall panels. Analyses of the results of those tests offer the opportunity to understand the effect of wide-ranging mining and geological factors on the overburden movement. For this reason, trips were made to coal mines of interest to interview mine management and collect their unpublished internal research reports on ground control instrumentation. In addition, literature searches on published thesis/dissertations and papers in the professional journals were performed. Finally, data from a total of 95 fully mechanized longwall panels were collected. The instrumentation involved primarily the monitoring of hydraulic pressures of longwall shields, from which the first roof weighting and first roof caving interval and periodic roof weighting and periodic roof weighting interval were identified and determined. Some panels also included measurements of roofto- floor convergence at the face, roof strata bed separation, longwall face sloughage and the height of caving and fractured zones in the overburden. Those 95 panels were located in 20 coal mines (Fig. 1) congregated along both sides of the Wulunmulun River with the following mining and geological conditions. All together those 20 mines produced more than 224 Mt (246 million st) in 2013, accounting for approximately 27 percent of the total coal production in the Ordos coal field:1. Period of mining: 1991-2013.2. Mining methods: All panels employed the one slice, full-seam natural-caving longwall mining method like those practiced in the United States. All panels were developed with a twoentry system with a single-row of chain pillars measuring 20- x 20-m (65.6- x 98.4-ft) wide.3. Coal seams (Fig. 3): Coal in Ordos coal field is high-quality steam coal, that is very low in sulfur, potassium and ash, but high in Btu. Data were collected in panels mined in a total of 10 seams with 82 panels in four seams and the remaining 13 panels in six seams. The first six seams (1-2, 2-2, 3-1, 3-2, 4-2, 5-2) were mined by the Shenhua Coal Group (the world’s largest coal company) and the #4-2, 5-2, 6R, 62, and 62R seams were mined by both the Shenhua and Yitai Coal groups. In each coal group, the sequence of mining was in descending order. For example, in Shenhua Group, the top seam 1-2 was mined first, followed by the 2-2, 3-1, 3-2, and 4-2 seam in that descending order. In Fig. 3, the top-down sequence of coal seams is listed from left to right in each coal mine group. All seams were near horizontal with dip angles less than 3°."

Jan 1, 2014

By Simon J. D. Cox, Nicholas J. Archibald, Steve Nichols, Peter B. Ketelaar, Donelle C. Davies, William L. Power

In the mining industry, there is a critical need to communicate complex, three dimensional information about the geology, ore reserves and development plans for mining operations. This information has to be communicated to a diverse audience, the members of which may not be trained in all of the disciplines required to create, utilise, or interpret the information. Software developed to support World Wide Web (WWW) activities has the potential to improve and change the way exploration and mining data and in- formation is organised, presented, and processed. In this paper, we discuss the creation of interactive displays of complex three dimensional data for the mining industry.

Jan 1, 1996