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By C. E. Rodgers

WHEN the writer was engaged early last year by Canadian Comstock and its subsidiary, the Metropolitan Electric Company, to act as Consulting Mining Engineer in connection with the layout and equipment of the new ore-dressing laboratories at Laval University, Quebec, the metallurgical laboratory section of the School of Mines building was completely erected, including plastered walls, partitions, etc., and finished concrete floors. At that time, however, no equipment had been ordered, except three Dominion ball-mills and two Bell screening machines. ADVANCED OR CONTINUOUS LABORATORIES The continuous laboratory section of the Department occupies the basement and three floors of the building, with an approximate floor area of 9,000 square feet. Because of limitations imposed by the design of the building (height and arrangement of rooms, strength and design of floors, etc.), modifications of layout from what otherwise seemed most desirable were, of necessity, made. These included: (a) Omission of automatic sampling of the dry ore. (b) Complete elimination of inclined belt-conveyors through floors. (c) Exclusion of bucket elevators for either dry or wet ore transfer. (d) As a substitute for grill-covered drains and floor sumps, drainage from sections or from individual pieces of equipment was piped to a disposal system in the basement. (e) Substitution in several instances of fabricated steel in place of the usual concrete foundations for machinery. (f) Reducing floor cutting and area of such opening to a minimum. Ore storage and chute capacity above the basement level was also minimized to reduce total weight.

Jan 1, 1941

By A. G. Mattes

This paper presents an overview of passive, engineered, biologically-based anaerobic bioreactor (ABR) treatment systems of the sort that can be used to remove dissolved copper from mine wastewaters. The paper begins with a brief history of the origins of this treatment technology and continues with a discussion of principles of engineered wetlands (EWs, advanced kinds of constructed wetlands, CWs) and the use of vertical sub-surface flow (VSSF) varieties that contain pulp & paper biosolids as the reactive medium for EW cells. A brief outline of a procedural methodology used in evaluating the potential for biological treatment on a site-specific basis is also included. An introduction to the microbiology of passive biologically-based treatment systems is followed by some recent research results in the general area of wetlands and ABR research. The paper concludes with a brief discussion of several sites known by the authors to have successfully (or not) demonstrated the potential of this treatment option.

Jan 1, 2007

By Sergio Samuel Sarmiento Sobrino

Dado que toda actividad minera genera relaves -en tanto son altas concentraciones de químicos y elementos que alteran el medio ambiente- estos deben ser transportados y almacenados en «tanques o pozas de relaves» donde lentamente los contaminantes se vayan decantando en el fondo y se pueda recuperar el agua. En ese sentido, el presente texto señala el manejo de relaves compactados en el depósito de Ramahuaycco, a través de desaguar los tóxicos antes de ser depositados. Así, los relaves filtrados son primero espesados y luego filtrados para el contenido de agua adecuado para su disposición. Por razones de estabilidad, los relaves filtrados requieren ser compactados a través de la desecación de relaves in situ.

Aug 1, 2015

By S. J. Swainson

PHOSPHATE ROCK is a low- priced commodity. This fact has influenced the choice of mining and beneficiating methods to a greater degree, perhaps, than in most other low-grade mining operations. The fact that many yards of everburden and matrix must be stripped and mined per ton of salable "rock" produced and sold has necessitated he development of relatively simple btneficiating plants having high capacity and low capital and operating costs. The law of diminishing returns must always be reckoned with in phosphate mining and washing, and often recovery must be sacrificed in favor of costs in order to achieve the highest over-all economic efficiency. The phosphate-bearing formation, known as "matrix," is composed of (1) phosphate pebbles, which are somewhat rounded in shape and which vary in size from 1-in, to micron sizes, (2) rounded quartz grains usually smaller than 10 mesh, and (3) clay, of varying "stiffness," which is the binder of the matrix. The phosphate pebbles vary in hardness. Their color, which varies from white to black, is not a reliable indicator of the Bone Phosphate of Lime (B.P.L.) content of the

Jan 1, 1944

By B Roache, J O’Brien, M Gray

Admixture use in cement products is commonplace in the construction and mining industries. Many Australian mines have an operational concrete batch plant and stock hydration control and water reducing admixtures. The benefits of admixture use, especially in shotcrete is understood and well documented. Cemented rock fill (CRF) is used to fill stope voids and create stable vertical and undercut surfaces at some Australian mines. These mines generally mix rock fill with a slurry of cement and water without the use of admixtures. Recently published work on optimisation of CRF mixes has mainly focused on the strength increases associated with changes to the mix grading proportions by the addition of fines, but not focusing on the potential benefits of admixture use. Admixture use in CRF may be the simplest CRF optimisation method, as the admixtures will often be added by the push of a button at the batch plant. A CRF testing program was undertaken to test the benefits of admixture use in terms of strength gain, using hydration control additives (HCA) and high range water reducer (HRWR) admixtures. Rock fill gradings were strictly controlled in the test process to allow clear definition of the difference admixtures provide in compression at 28 days. The testing results define admixture associated strength gains in a 6 per cent general purpose (GP) cement by dry weight CRF mix (131 kg of cement/m3). Costings have been developed to allow a mine operator to understand the cost benefits of admixture use in CRF due to reduced operating costs. Operational efficiency advances and a suggested admixture implementation plan for CRF optimisation is offered.

Nov 29, 2022

By J Li, J Regan, D Payne

The Caval Ridge Mine is an open cut coalmine and located within the Bowen Basin region in Central Queensland, and commenced mining and processing operations in 2014. A number of geotechnical challenges for managing dragline bench and lowwall stabilities have been encountered in both southern and northern pits over the years. Southern Pits contain steep seam dips of up to 15° (27 per cent) whilst the northern pits also have shears below pit floors. Geotechnical guidelines to manage the risk of dragline bench failure and lowwall instability have been developed and improved since these geotechnical challenges were identified. The dragline guidelines include dragline tub offset distances from the 60° Line (SDL) or buttressing thickness for different seam dips greater than or equal to 8°. The low wall stabilisation guideline established floor disruption widths and depths depending on seam dips and presence of floor shears to known depths of up to 3 m. As mining operations advance, lowwalls have remained stable until floor disruptions were fired, then returned to stable soon after the shot. The maximum distance of lowwall cracking with blasting has been as far back as the second spoil peak (the prestrip truck dumps construction limit). These failures need to be eliminated to allow the operational flexibility and haulage benefit of constructing the prestrip truck dumps behind the first spoil peak, while maintaining no risk to personnel or equipment. The floor shear depth was verified by collaborating with the exploration teams and taking advantage of the already planned 8-inch coal quality core holes, drilling them an extra 5–10 m past the coal seam floor and locating the shear presence. With this continuous improvement effort, no lowwall failures have occurred during floor disruption firing from the second strip after the new floor disruption depth guidance have been applied. This paper documents the processes for developing these geotechnical guidelines, operational implementation, and outcomes. Operational applications over the years confirmed that these guidelines have effectively managed the dragline bench and lowwall failure risks related with the steep seam dips and floor shears in this open cut coalmine.

Nov 29, 2022

By Will H. Coghill, I. L. Feld, G. D. Coe

The object of this paper . is to make known the superior classification accomplished in a hydraulic classifier designed to make use of principles determined by recent research ... The details of the design , the results of preliminary research , and the final testing are given . The classifier of the new design shown in figure 1 and another one like it are in operation as concentration classifiers in a Birmingham iron- ore mill recovering 4 tons per hour of concentrates from table middling that ` otherwise would require regrinding and retabling . The four factors that contribute to the successful operation of these classifiers are ( 1 ) a teeter column of small diameter , ( 2 ) use of an open - bottom tooter column classifier with a periodic pincer instead of the usual type , which terminates in a vortex, ( 3 ) a sorting chamber under separate hydraulic control , and ( 4 ) a teeter column of more than the usual depth . · At the outset it must be stated positively what the authors mean by hydraulic classification : They mean the reconstruction of a multimineral ground product into fractions graded with respect to size , so that cach fraction has the heavy mineral segregated in the fine sizes and the light mineral segregated in the coarse sizes . This definition presupposes that in multiplespigot classification the low specific gravity minerals are carried beyond the first cells to the later ones . The reader must take into account that , from the standpoint of classification , " ores " may be divided into two types , represented - by the following : ( 1 ) Joplin flint - blende ores , which , because of the hardness of the flint and the softness of the blonde , yield upon comminution a product that already has the essence of classification ; and ( 2 ) Birmingham Big Seam iron oros , which contain " easily shelled - out " sca sand and , upon reduction to about 10 mesh , yield a heterogeneous mixture in which the size analyses of the respective " floats " and " sinks " arc almost identical .

Dec 1, 1945

By S Doudle

The Iluka Resources Ltd Jacinth-Ambrosia heavy mineral sand mine (South Australia) is located in an undisturbed semi-arid landscape consisting of sparse trees, shrubs and grasses. The soil interspaces are covered with biocrusts, a living soil cover also found worldwide in arid regions. Biocrusts are composed of lichens, cyanobacteria, algae, mosses, liverworts, fungi and bacteria, and live on and within the first few millimetres of the soil surface. Biocrust organisms bind soil particles, sequester carbon and many fix atmospheric nitrogen making them important structural and functional components of ecosystems. Despite their important role in ecological processes, biocrusts are susceptible to disturbance; nevertheless they can recover provided sufficient inoculum is present. Cyanobacteria are the early colonisers and they capture atmospheric and landscape resources and establish conditions that subsequent successional seres can capitalise on. Research conducted in countries including China, Spain and South Africa has been focused on methods to either encourage rapid regeneration of cyanobacterial remnants or to introduce new material from cultured cyanobacteria. We have been investigating the extent and diversity of biocrusts across the 4500 ha mine lease and their potential to improve mining rehabilitation outcomes. Approximately 46 per cent of the soil surfaces are colonised with biocrusts and 33 taxa have been identified. Laboratory experiments were designed to mimic massive soil disturbance and treated with a range of water qualities. Within 22 days, treatments irrigated with fresh water were colonised by new cyanobacterial filaments with a mean surface coverage of 65 per cent. Secondary tests revealed that differences in the photosynthetic yield of the crust were dependent on the salinity levels of the irrigation water used. In 2011 this program is expanding from the laboratory into field scale trials designed to assess both the potential and practicalities of up scaling these techniques to provide crushed biocrusts and cyanobacterial bio-inoculum for use in mine rehabilitation.

Oct 5, 2011

Agenda ? Introduction ? Inmet?s Operations and Closed Properties ? Inmet?s SECA Philosophy ? Inmet?s SECA Framework ? The Business Case for TSM ? Inmet?s TSM Reporting ? Inmet?s 2004 TSM Performance ? Opportunities for Improvement ? What Have We Learned From The TSM Process So Far? ? Summary Introduction ? Inmet has evolved into a strong TSM supporter ? Inmet is confident that TSM can be successfully and cost effectively implemented by smaller companies ? Inmet?s reporting on economic, environmental and social performance was raised significantly in our 2003 Annual Report ? a signal our commitment to good performance and improvement in these areas ? Our 2004 Annual Report has been further enhanced with the inclusion of our TSM performance

Apr 1, 2005

By A. C. Halferdahl

The Granby ores may be divided into three groups or classes. The No. I ore is a heavy pyrite, chalcopyrite, pyrrhotite, sulphide carrying some free silica, and calcite. No. 2 ore carries the same general group of sulphides as does No. 1, but in a lesser amount. The gangue is an altered greenstone. No. 3 ore has a smaller amount of sulphides than either of the others. Analyses of these ores is as follows: Cu. Si02 Fe. CaO S. Al 203 MgO No. I. Per Cent. 1.8 17.5 33.0 5.7 34.5 2.3 1.3 No. 2 Per cent. 2. 0 35. 6 23. 9 4. 3 I .5. 0 9. 2 6 .. 0 No. 3, Per cent. 1 . 5 40. 9 21 . 7 3. 0 I 1 . 3 11 . 0 5 . 4 The sulphide minerals in No. 2 and No. 3 ores occur largely in bands in the gangue, and for these portions comparatively coarse grinding serves to release the gangue. Drill cores show a certain dissemination of sulphides in portions of the rock, so that grinding to 5 per cent. + 65 mesh with 65 per cent.-200 mesh liberates the sulphide minerals very completely. The association of the sulphides is fundamental. The pyrite was probably deposited first and was followed by a portion of the chalcopyrite, or these two portions of the sulphide minerals were deposited together.

Jan 1, 1924

By R. R. Faddick

A mineral slurry data hank has been compiled, containing slurry pipelining data on sixteen ores, concentrates, and tailings. The data bank it in the form of a computer print-out all they necessary system constants and headloss data for each mineral commodity. The purpose of the data bank was to assist in the development of a universal head loss correlation for mineral slurries, if such a thing exists. Present headloss correlations were tested and found to be inconsistent for the various mineral slurries. Consequently, a different approach was taken, that of compiling a library or Stanton diagrams relating friction factor and Reynolds numbers for a given slurry in a given pipe diameter. The advantages of the diagrams arc demonstrated and discussed. While this correlation shows excellent potential, it is necessary that additional work, both theoretical and experimental, be performed. In addition, two equations are given from which a design velocity may be obtained to minimize deposition or formation of bedload. The equations are based on data taken from the mineral slurry data bank.

Jan 1, 1972

By C. A. C. Sequeira, G. N. Anastassakis

"The separation of fine or even smaller size mineral particles with conventional methods is inefficient due to the specific properties of fines (small mass, high specific surface area, and high surface energy per unit area). Hence, the production of high-grade concentrate with high recovery is very difficult to impossible and a significant share of mineral values is lost to the tailings. The aim of the current research is to investigate the possibility to efficiently separate value minerals from gangue of fine particle size. The objective of the current work is to develop separation schemes of fine mineral particles by combining an initial stage of particles agglomeration with the use of collectors (hydrophobic agglomeration) with a subsequent conventional separation method. In the current research, magnesite was used as mineral value to be separated: a) from quartz, and b) from mineral mixture (serpentine, ilmenite, and olivine). In each case, tests on single minerals and artificial mixtures were carried out. After hydrophobic agglomeration, the separation of magnesite from quartz was achieved by settling; in the second case (gangue: serpentine, ilmenite, and olivine), magnetic separation of the co-agglomerated gangue was applied. In both cases, the results of the preliminary tests on single minerals suggest that the separation of mineral value is feasible and efficient. These findings were also confirmed from the results of the tests on artificial mixtures of magnesite and gangue, either quartz only or mineral mixture. Both separation schemes provided with magnesite concentrates of commercial grade (95% magnesite) with high recovery. INTRODUCTION The generation of fine particles is inevitable in many operations of mineral commodities processing. Especially in the case of low-grade ores, the mineral value is finely disseminated in the ore, and considerable liberation occurs at a fine size range. Although there is not a uniform classification system with respect to mineral particles size, fines are usually characterized the particles with a size range of -100µm+20µm, very fines those of -20µm+5µm, ultra fines of -5µm+1µm, and colloids smaller than 1µm (Sivamohan, 1990)."

Jan 1, 2018

By R. L. Grayson, S. S. Peng

"Research has been conducted during the past year on a study to correlate respirable coal mine dust characteristics with worker positions and coal seams. The first characteristic of respirable coal mine dust which has been addressed in the correlation study is respirable dust mass concentration. In fulfillment of this objective, two mines operating in different coal seams have been selected for respirable dust mass sampling on both longwall panels and continuous mining sections. At present, sampling has been completed on the longwall panel operating in the first mine, and one half of the planned sampling has been accomplished on the continuous mining section.The first mine sampled is operating in the Pittsburgh coal seam. The average mining height is approximately 78"" with an average of 8"" of bottom shale being mined. The mine is primarily a longwall mine, and continuous mining machines are used to support the longwall.Figure 1 shows the layout of the longwall panel which was sampled. Intake air is coursed via the track heading up to the headgate area. The air splits at the headgate. Approximately 20,000-30,000 cubic feet of air per minute (CFM) is used to ventilate the longwall face and about 5,000-10,000 CFM is routed down the belt entry. Substantial leakage across the gob was noted during the sampling period. An average of 1800 CFM per 100 feet of face leaked through the shields into the gob from #1 shield to #112 shield. A substantial amount of leakage also occurred between the #1 shield and the solid rib of the headgate development panel. The path of the air used to ventilate the panel is shown with arrows in Figure 1. Direction of air flow was opposite to the coal moving direction on the armored face conveyor.A double-drum ranging shearer is used on the face to cut a 30-inch web of coal. Normal practice is to cut from the tailgate to headgate with the leading drum raised and the tail drum lowered for cutting bottom. After reaching the headgate, the shearer is reversed and both drums are lowered for a clean-up pass. The last 40 feet of face on the tailgate is cut on the clean-up pass.The shearer is equipped with 2 banks of 4 water sprays each and 2 large sprays on the headgate end and 1 bank of 4 sprays on the tailgate end. Additionally, sprays are located above bits on the cutting drums. Actual cutting speed was approximately 14-18 feet per minute, depending on conditions.The cross sectional area for air flow on the face was approximately 60 square feet before a pass was mined and 80 square feet after a pass was mined but before the shields were advanced. The cross sectional area at the shearer was about 35 square feet.The condition of both the tailgate and headgate of the panel was good with no signs of significant roof problems. The roof conditions along the face during the sampling period were variable. At times, as much as 3 feet of drawslate fell from the roof for a span of as much as 40 shields. Generally, however, relatively local areas of falling roof were encoun-tered, usually limited to a 10-20 shield span when appearing.Ten days were spent gathering respirable dust samples on the longwall panel. Mine Safety Appliance (MSA) sampling units equipped with 10-mm nylon cyclones, pre-weighed MSA PVC filters, and constant-flow DuPont pumps were used to obtain thesamples. The pumps were calibrated at a 2 liters-per-minute flow rate. The 10-mm cyclone was selected for classifying total dust into the desired respirable fraction in order to obtain ""legally defined"" respirable dust samples for detailed physical characterization."

Jan 1, 1988

By R Valenta, A Littleboy

Geological heterogeneity is one dimension of complexity in mining. Significant effort is put into developing an understanding of this complexity so it can be used in resource estimation, mine planning and economic modelling. However, over the decadal lifespan of a mining venture, many other dimensions add to the complexity of a mining operation. These include: technological evolution, market fluctuations; investor confidence; social norms; local expectations; and ecosystem functionality. As with geology, these factors are all heterogeneous, uncertain, time varying and represented through sparse and incomplete datasets. Recent work (Valenta et al) is beginning to show us how these risks correlate in different global settings. By analysing data relating to known, but as yet undeveloped copper deposits, this work (the complex ore body database) is demonstrating that it is the combination of issues (both price sensitive and non price-sensitive) that determine the viability of a deposit for extraction in the 21st century.CITATION: Littleboy, A, Plint, N and Valenta, R, 2018. Mining as a complex system: do we need a new model?, in Proceedings Complex Orebodies Conference 2018, pp 41–43 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Peter Van deVelde

Many companies in North America because of economic or environmental reasons are considering reprocessing material from their waste ponds. The Japanese have developed highly specialized machines and techniques to reprocess industrial/mining wastes from settling ponds. This paper discusses the techniques and results of applying this technology to North American applications.

Jan 1, 1983

By Frederick P. Agterberg

It can be useful to model the mean grade values for a metal in mineral deposits containing that metal as representing the extreme value tail of a lognormal frequency distribution for the concentration values of the metal in rocks of all types. Results for copper and zinc in the Abitibi area of the Canadian Shield are compared to results previously obtained for the Canadian Appalachian Region. The lognormal model is also applied to a set of 162 large gold deposits in the Abitibi area. In the second part of the paper, 1311 large and small gold deposits in the Abitibi area are modelled as discrete events. By means of a newly developed spatial clustering model it is possible to predict the variances of random variables for frequencies of deposits in cells of different sizes.

Jan 1, 1979

By Alan A. Campoli

The U.S. Bureau of Mines conducted research to characterize longwall gob loading under bump-prone geologic conditions. Bureau-designed stress meters were installed in the floor rock beneath two longwall panels and coal pillars in the gate road between them. Gob and gate road pillar stress was monitored continuously by a state-of-the-art data acquisition system. The timing of the final destruction of the abutment pillar's load-bearing core was optimal, since the pillar is located between two gob areas and no longer of significant importance for ground control. Maximum stress was observed immediately in front of the longwall face, and this pressure quickly dropped as the face moved past the instruments. The center of the longwall panels regained significant overburden load, while the instruments located less than 100 ft from the edge of the panel showed little or no increase in pressure due to gob reloading.

Jan 1, 2010

By Robert J. Evans

The Bureau of Mines is sponsoring a variety of long-term, high-risk research to advance state-of-the-art technology in U.S. underground coal mining. This report reviews the status of many Bureau projects that support fundamental underground coal mining operations; the project areas include cutting coal from the solid (extraction), hauling coal from the face (transport), and activities that sustain daily operations (logistics). Innovative equipment and technology have been developed, with these major objectives: to significantly improve coal mine productivity, to further advance coal recovery and personal safety within the mining industry, and to reduce the time needed to develop longwall panels. The majority of the prototype equipment covered in this report either has undergone or will undergo comprehensive evaluation at Bureau surface test facilities so that performance and reliability can be improved before the equipment is tested and evaluated in a working section underground.

Jan 1, 1988

By P. R. Bailey

The use of carbon for the recovery of the gold dissolved in cyanide leaching began with a pilot unit at Barberton in 1977. This was quickly followed by larger scale plants at Modderfontein (1978), President Brand (calcine 1980), Western Areas (filter tails 1980) and Beisa (primary ore 1981) and has grown to become the preferred process. There are currently 34 operations that use the carbon in pulp/leach process which accounts for 35 percent of South Africa's gold production. The size of individual plant varies over a wide range.

Jan 1, 1993

By P J. Bangerter, J Pan

Optimising for Net Present Value (NPV) with a strategic optimiser such as COMET, Prober-E, Blaser or Minemax has hitherto lacked a dynamic method for analysing the so-called third-order outcomes (such as Carbon emissions) of optimisation within life-of-mine planning. Optimisation, per se, has natural effects on carbon emissions in a life-of-mine plan. Contemporary strategic planning employs a mathematical optimiser to make sense of non-linear data (ie a block model) and produces a best-NPV optimised mining schedule, within a set of constraints. The very act of optimisation influences emissions, and in a dynamic way.

Aug 2, 2023