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By D Laskovski, T Nguyen

Flotation surveying can be an extremely powerful means of determining opportunities for circuit optimisation and benchmarking. The type of survey employed depends heavily on the nature of the information required from the survey. It follows then that the type of survey determines the type of samples required; however, regardless of the type, the success or failure of a survey is often dependent on the correct used of appropriate sampling techniques at each sampling point. For a successful flotation plant survey it is vital that the correct samples be collected at the correct time in respect to the feed and each other. This paper discusses the current best practice sampling methods used in flotation surveying and discusses in detail the ideal sample masses based on theoretical analysis. Comparisons with JKTech’s database of real plant operations will then be made.CITATION:Laskovski, D and Nguyen, T, 2014. An investigation of current flotation survey sampling, in Proceedings Sampling 2014 , pp 99–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By N. C. J. Dempers, J. A. L. Parker, R. A. Wildenboer

More than half of global cobalt reserves are located in the Southern African Copperbelt, stretching over the northern tip of Zambia and southern area of the Democratic Republic of Congo. In these areas, cobalt is not typically produced as a primary product but as a byproduct of copper production. Ores from this region often contain uranium, which is readily leached under typical copper leach conditions and enters the process. Uranium does not pose a challenge to copper production, but it becomes a significant problem when it follows cobalt to the cobalt precipitation process and results in unacceptably high levels of U in the final Co product. This paper evaluates the existing process technologies that can be used to remove uranium from cobalt-bearing process streams, including phosphate precipitation and ion exchange. Advantages and disadvantages of the uranium removal processes are discussed, and important design considerations are highlighted.

Jan 1, 2023

By Willard L. Cumings, Benjamin L. Miller

(Glen Summit Meeting, June, 1911.) I. THE CAMAGUEY DEPOSITS. 1. Location. THE Camaguey brown iron-ore deposit covers the top of San Felipe hill, the nearest point of which lies 14 miles NW. of the city of Camaguey. While there are several low flat-topped hills in the vicinity covered with a more or less continuous mantle of brown iron-ore, the deposit of San Felipe hill is the only one of any size and importance, and the name "San Felipe district " is proposed for the region. The deposit extends in a NW-SE. direction for a distance of about 10 miles, with an average width of 5 miles. The location is shown in Fig. 1, a sketch-map of the eastern part of Cuba. Fig. 2 is a map of the San Felipe district. 2. Description. The district is mentioned by Spencer,1 who says: "The Cubitas iron-ore fields are situated from 12 to 15 miles north of Camaguey City, in the province of Camaguey Within an area measuring roughly 10 miles east and west and 4 miles north and south, there are several flat-topped mesas rising 300 to 400 ft. above the level of an almost featureless plain which extends for many miles in all directions except toward the north." With the exception of the discrepancy in his statements as to the distance from Camaguey and the area of the hill, which is over 50 sq. miles, his description is a very good one. Kemp 2 has the following to say of ores in Carnaguey Province * Geologist, Bethlehem Steel Co. + Professor of Geology, Lehigh University. 1 Bulletin No. 540, U. S. Geological Survey, p. 324 (1908). 2 The Iron Ore Resources of the World, printed by the Eleventh International Geological Congress, vol. ii., p. 795 (1910).

Mar 1, 1911

By Bryan Buchholz, N. Kumar Kittusamy

Previous studies indicate that operators of heavy construction equipment are afflicted by musculoskeletal injuries of the arms, shoulders, neck, and lower back. These injuries appear to be due to excessive periods of sitting (static posture), work intensity, whole-body vibration, high resistance levers, repetitive motions, and awkward postures. (2-5) Although numerous studies have shown an association between operation of heavy construction equipment and symptoms of musculoskeletal disorders, very little research has been performed that systematically characterizes operating engineers' exposure to ergonomic hazards. The objective of this study was to systematically characterize the ergonomic hazards associated with excavating operations. As such, the following were performed: (1) vibrations were measured at the operator/seat interface (X, Y, and Z axes), and at the floor of the cab (Z axis); (2) psychophysical ratings of whole-body vibration (WBV) level and overall seat design were obtained; and (3) postural assessments of the job were made. Methodology This study evaluated an inexperienced female operator performing excavation, utilizing two different pieces of equipment. The operator was 37 years old, 162 cm tall, and weighed 80 kg. She had approximately 15 hours of operation time (experience) on the equipment evaluated. The two pieces of equipment used were: a Case Super 580E (1986) backhoe/loader, and an Insley H-2000 excavator (1975) (see Figures 1 and 2). More evaluations were performed on the backhoe/loader than on the excavator. The following evaluations were performed on the Case equipment: 1) vibration levels at the seat and floor; 2) psychophysical ratings of the overall seat design and vibration levels (for the task duration, and for an 8 hour duration); and 3) postural assessments. For the Insley equipment, all of the evaluations were performed except vibration measurements. When the evaluations were conducted, the following environmental conditions were noted: the temperature was 31°F, and soil and terrain conditions were rough and frozen.

By Minchinton A

CPeX is a non-ideal explosive performance prediction model. The model takes into account the rate of energy release, the extent of chemical reac- tion and the effect of confinement on energy release. The model resolves the explosive energy into `shock' and `heave' com- ponents as a function of explosive type, hole diameter and rock type. The predictions of the model are compared for a bulk emulsion, and a prill-doped bulk emulsion in soft rock. The predictions, based on calibra- tion of the model with simple unconfined detonation velocity measure- ments, show the significant effect of non-ideality on explosive Performance.

Jan 1, 1988

At a regional scale, the Otago Schist has been divided into textural zones, metamorphic zones, structural transposition zones, and terranes and lithologic associations. Each of these subdivisions reveals aspects of the internal structure of the lithologically monotonous Otago Schist but, to date, a map of the schist derived directly from structural data has not been made. In the present study, digitised structural data from the QMAP GIS were used to make a form line map of Schist foliation which, in turn (and using certain non-unique guiding assumptions), was used to construct a provisional foliation thickness map of the Otago Schist. Contours of dominant foliation (Sp) thickness have been drawn from 4 kIn above to 16 km below the reference level of the Caples-Torlesse terrane boundary in the schist structural pile. A recent revision of the Otago Schist textural zone classification has shown that the grain size of metamorphic white micas increases progressively with textural grade. There also appears to be a correlation between schist mica grain size and foliation thickness. Using mica grain size, it may eventually be feasible to establish the vertical structural position of samples in greenschist facies parts of the schist pile to a precision of ¦ 1 km or better, even if they are in inliers or fault-bounded blocks. Foliation thickness and mica grain size are thus potentially useful tools for research and exploration in the Otago Schist in that they assist with structural interpolation and extrapolation. Even at this early stage of application they can be used to provide hitherto unobtainable, semi-quantitative estimates of displacement on Mesozoic and Cenozoic faults and folds.  

Jan 1, 2001

By Nabil F. Ismael

The axial capacity of step tapered bored piles in sand was examined by field tests at one site in Kuwait. Two straight piles, and two step tapered piles were load tested in compression to failure. All four piles were 3 m deep. The straight piles were 0.2 m in diameter. The step tapered piles had a diameter of 0.3 m for the upper segment which extended up to 40% of the pile length changing to 0.2 m diameter for the lower section. The soil profile consists of medium to dense sand with minor cementation and no groundwater was encountered. Both the ultimate bearing capacity and the settlement at working loads were examined. The axial capacity of the step tapered piles was greater, and the settlement at working loads was less, compared with the straight shaft piles. The increase in capacity is mainly attributed to the added side friction along the larger diameter top segment of the shaft.

Jan 1, 2008

By C. Newman

"As underground mining continues to operate at deeper depths and in more complex multiple seam mining geometries there has been an increased demand for higher design standards in ground control safety and stability within the mining industry. For the past 20 years, NIOSH has developed and validated a number of software tools to aid in the development of safer mining environments with respect to improved roof support performance, pillar stability in longwall and room and pillar mines, formation characterization, the prediction of roof conditions, etc. These tools are available, free of charge, to the mining industry as stand-alone software packages. As cloud computing gains momentum, there is a definite need to develop internet based applications for mine design that would be easily accessible to any user at any time, including underground where permitted. This paper introduces a new web-based product which will allow for faster and easier access to existing ground control designs, on-the-fly calculations in the field as needed, and instant online collaboration between operations personnel and planning engineers. It is expected that the industry will rapidly embrace this product and, as it is common with all new innovative technologies, it will be a new paradigm for mining engineering computer applications. INTRODUCTION Since its release to the public in the late 1980's, the World Wide Web has drastically changed from a collection of static HTML web pages to a dynamic vehicle driving e-commerce, collaborative working relationships, and the mass distribution of information and media (Offutt, 2002). Recent developments in Internet capabilities, such as Cloud Computing and Software as a Service, have begun a migration away from desktop-based software in adoption of the web application (Hayes, 2008). Web applications, or web apps, are designed on the client-server architecture paradigm in which the client, or user, can interact with an application through web browsers without disrupting or installing software on potentially thousands of client computers (Nations, 2015). Currently, web-based software applications are being utilized in all business sectors and markets from commerce, finance, media, and even engineering. In fact, the Alabama Department of Transportation has developed a web-based geotechnical geographical information system (GeoGIS) for the management of and access to geotechnical and subsurface data for transportation projects across the state (Graettinger, et al., 2001). Similarly, Dyno Noble has developed a service application for explosive engineers. The Explosives Engineers' Guide application equips users with a full range of product information as well as on-demand blasting calculations for powder factor, airblast prediction, ground vibration, etc. Through the incorporation of a web server, one is able to utilize the functionality of the desktop-based software through a web browser located on any personal computer, tablet, or Smartphone (Vaughan-Nichols, 2002)."

Jan 1, 2016

By Roy S. Nutter

The automation of coal mining must occur in a manner that is economically beneficial to the industry and that enhances the safety of the underground and surface workplaces. The work at WVU over the last five years in applying expert systems and neural network controlled autonomous robotics provides the mining industry with tools that when properly applied should clearly lead to mine-wide management and operational improvements and should also contribute to a higher awareness of safety issues by all work crews. This work includes the development of MMSS (Mine Management Support System) and the detailed development of autonomous robotics utilizing neural networks for mining systems.

Jan 1, 1993

By P Revell, B Adair, D King, L Keeney

Grade Engineering®, integrated across the mine value chain, has a pivotal role to play in achieving step change reductions in energy and water usage in mine operations. High levels of gangue rejection in the mine can significantly improve mineral head grades and overall productivity. A highly successful example is described at the Minera San Cristóbal (MSC) operation. The nature of the mineralisation in their “intrusive” ore domains in particular has facilitated high rejection rates (75 % of the mass), with significant upgrading of metal to the “accepts” streams (equating to a 2.6 times upgrade in the intrinsic Nett Smelter Return). Results from a series of production trials have confirmed these strong upgrades, resulting in the transformation of mineralised “marginal wastes” to high grade ore feedstocks. If new approaches to more energy and water efficient comminution and separation technologies can also realise gangue rejection at finer sizes in the concentrator, then preconcentration strategies across the value chain also offer the promise of no wet tailings treatment facilities and greatly reduced volumes of waste streams. This “No Tails” strategy is discussed, along with the integrated technologies needed to realise its effect. The work suggests a pathway and insights of a sustainable future for the Minerals Industry, unconstrained by Energy and Water, along with no requirement to produce problematic disposal streams. This strategy has the potential to significantly reposition the social, environmental, financial, and regulatory context of existing and new mining opportunities.

Nov 10, 2020

By Nan Wang

Based on the commercial computational fluid dynamics software, Fluent, the fluid flow and temperature field in an iron-bath reactor were simulated numerically, and the effects of top-blown and side-blown operating parameters on the mixing time of iron bath, distribution range of oxygen in top space, and post-combustion ratio were investigated. The simulated results showed that the mixing time of iron bath increased initially and then decreased with the increase of inclined degree and immersion depth of side-blown lance. The distribution range of oxygen became wider as pulling the top lance away from the iron bath. Furthermore, post-combustion ratio was reduced given the top lance was too close the bath. The simulation results provide theoretical base for the process optimization of iron-bath reactor and further development of new type iron-bath smelting reduction process.

Jan 1, 2009

Mining and the related extractive and processing industries are chiefly responsible for America's high standard of living. Enormous quantities of sand and gravel, limestone, copper, iron and a myriad of other mineral commodities are required to sustain our growing nation. However, the mineral deposits, both domestic and foreign, are becoming increasingly difficult to find. Adding substantially to the problem, is the fact that the conditions are worldwide. Foreign politics are increasingly affecting mineral commodity availability. Figure 1, taken from Bureau of Mines, "Status of the Mineral industries 1976" illustrates our dependency (in some cases total) on foreign sources for vital mineral commodities. While few nations are capable of exerting an OPEC-like influence on any one mineral commodity, the threat of cartel arrangements and related control strategies is evident. Nationalization of entire industries, once they become self-sufficient, is also exerting a disruptive influence on a large portion of the mineral industries.

Jan 1, 1977

By Simón Díaz‑Quezada, Ernesto Arancibia, HUMBERTO ESTAY, Tomás Vargas

In situ leaching (ISL) is an attractive technique that enables copper recovery from copper oxide ores that are either low-grade or located at depths too great to be economically exploited through conventional methods. At present, in situ leaching (ISL) has been applied to intact copper oxide ores, in particular, those which (i) present a good natural permeability and (ii) do not require preconditioning. Many copper oxide ores present low natural permeability. These are located above the water table and need preconditioning for the ISL application. The present work shows an economic assessment of the application of ISL to this type of copper ores. The preconditioning technique considered here involves the application of partial mining by sublevel stoping by removing a small fraction of the ore. This technique results in forming an ore bed with good permeability and good solution collection at the stope base. The economic assessment of this approach suggests that it can be implemented with positive net present values to copper oxide ores located at depths in the 100–300 m range, with copper grades above 0.4%. The maximum acid consumption values are below 52.5 kg/t, with blasting procedures designed to produce an ore bed with an average particle size below 6″. The breakdown of operational costs indicates that the mining cost is still very high, accounting for up to 60% of the total operating costs. Therefore, optimizing mining procedures is still necessary for improving the economic outlook of this approach and thus expanding the application field of ISL.

Feb 4, 2023

By J. Molgaard, J. Masounave, J. Prinsen, P. Beaulieu, G. Huard

"A study carried out on behalf of the National Research Council (NRC) indicates that economic losses due to wear in the Canadian mining industry are in excess of $700 million annually. Severe wear, mainly by abrasion, was identified as the most important wear mechanism in terms of possible savings. One way to reduce losses would be the proper use of databases. A joint project of The Canadian Institute of Mining and Metallurgy (CIM) and NRC (Tribology laboratories at IMRI) has been initiated to create a factual database containing all relevant experience in the area of wear in the Canadian mining industry. As a first step, a prototype covering slurry pumps is being built. This should help to answer many questions, such as the number of people involved, interest from industry, cost vs benefits, etc.IntroductionTribology is concerned with the understanding of the mechanisms of friction, wear, and lubrication.Tribology is concerned with the correct use of materials for interacting solid surfaces, with the interaction of those surfaces with lubricants, with the chemistry, physics and use of lubricants and their additives. It is concerned with the reduction of friction and wear (or, in the case of belts, brakes, clutch plates, and similar devices, in achieving optimum friction with minimum wear) and is concerned with the avoidance of associated failures in machinery.Lubrication is usually the solution to a problem of friction and wear. Yet far from all the problems of friction and wear are solved by lubrication. The wear of grinding rods or shovel track pads can hardly be solved by lubrication, to name just two examples with which mining engineers will be familiar. There are indeed many situations of wear and friction where the surfaces in contact are unlubricated.In part, tribology is a matter of design. A major aspect, however, has to do with the choice of materials, to satisfy external constraints upon the component design or choice. The operating conditions for much industrial equipment, particularly in mining are, often very severe. The development of wear resistant materials, including materials which are applied as coatings, is clearly an important technology from the point of view of tribology."

Jan 1, 1987

By G. A. Brady

Laboratory tests were conducted to determine the technical feasibility of separating anthracite particles from a water-anthracite slurry by atomizing the water and removing the resulting mist in an air current. Products containing 21 percent or less moisture were obtained from slurries made with minus 60-mesh anthracite. Typical recoveries ranged between 67 and 79 percent of the feed when the slurries were atomized in air currents with velocities below 70 ft/min.

Jan 1, 1967

The principle activities of the Explosives Research Laboratory from July 1, 1961 to June 30, 1962, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1962; in general, the research reported in these publications antedates the report period. Part 3 gives the results of an investigation which, although too limited to warrant separate publication, merits presentation in some detail because of current interest in ammonium nitrate-fuel oil compositions.

Jan 1, 1964

By Xiaoning Yang, C David Pearson, Brian W. Stump

An experimental study of ground motion from explosions designed to remove overburden in an open pit coal mine is reported. The purpose of this study is a characterization of these ground motions in the distance range of several tens of meters to several kilometers. The investigation has focused upon both single cylindrical sources with different explosive configurations as well as arrays of charges in the production mode. Critical to this study of source configuration and coupling is experimental control of the individual explosions, the timing of the explosions and the geological properties. The height of the explosive charges, their depth and charge distribution were monitored in the field. High speed photography as well as velocity of detonation measurements were made on the multiple explosion source so that detonation of individual charges could be documented.

Jan 1, 1994

By John C. Holtz

Information on the gaseous products from the detonation of explosives has been obtained in two ways. In the first, the atmosphere in nines is analyzed after blasting, aid in the second, the gases found after detonating an explosive in a testing apparatus are analyzed. The Bureau of Mines, in

Jan 1, 1940

By G. Bierie

The conveying of bulk materials is prone to problems. These problems can reduce the capacity and efficiency of the plant, and even threaten the health and safety of the workforce. This presentation will look at new conveyor technologies systems, and how, used separately or in combination, they can improve material handling.

Jan 1, 2007

By Raymond T. Moore

The Federal Coal Mine Health and Safety Act of 1969 (FCMHSA) begins with this statement: "Congress declares that the first priority and concern of all in the coal mining industry must be the health and safety of its most precious resource -- the miner; . . ." At the Federal level this responsibility is shared by the Department of the Interior and the Department of HEW. The health research and standard setting activities under the Act are largely the responsibility of the Department of HEW, and with the exception of Title 4, Black Lung Benefits, have been delegated to our Institute, which I will refer to henceforth as NIOSH. In addition, we bear certain joint responsibilities with the Department of the Interior. These include dust sampling and respirator approval. To complete the picture, the Department of Labor has recently assumed Black Lung Benefit respon¬sibilities from the Social Security Administration under Title 4 of the Act.

Jan 1, 1974