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By M. Dworzanowski

Beneficiation, in the context of this paper, has two distinct definitions. From an economic perspective, beneficiation relates to adding value to a mined raw material. From a metallurgy perspective, beneficiation relates to processes used to upgrade the mined raw material. Clearly then, ?economic beneficiation? is dependent on ?metallurgical beneficiation?. South Africa possesses the world?s largest mineral resources by value and is a significant global producer of many mined commodities. Significant metallurgical beneficiation of ores does occur in South Africa. The role of metallurgy in economic beneficiation will be examined in terms of current practice and the potential for expansion. South Africa?s main mining commodities will be covered ? namely gold, platinum, coal, iron ore, manganese, chromium, vanadium, copper, nickel, titanium, zirconium, uranium, and diamonds.

Sep 1, 2013

By S. Y. Tan

The thermal stability of fully silicided NiSi with arsenic doping on silicon was investigated. The aims of the work were to investigate the Ni silicide phase-related issues associated with arsenic dopant and thermal annealing on Ni-FUSI/HfO2/Si and Ni-FUSI/HfSiO/Si gate stacks. It was found that arsenic-incorporation demonstrated some improvement in both morphology and phase stability of nickel silicided films at high processing temperatures regardless underlying gate dielectrics. The correlations of Ni-Si phase transformation and arsenic doapnt with their electrical and physical changes were established by sheet resistance measurements, X-ray diffraction (XRD), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) analysis. Furthermore, the modulation of the work function (WF) of Ni fully silicided gates by arsenic impurity is presented, comparing the effects of dopant (As) on the WF and silicide phases (NiSi and NiSi2). It confirmed that the work function of NiSi can be tuned by implanting arsenic dopant, but it ineffective for NiSi2 phase.

Jan 1, 2010

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

The mechanization of the coal industry in New South Wales involved the introduction of large face and transport machines. The trend is towards still higher capacity units with .greater horsepower and it became apparent that a potential risk of damage to the hearing of workmen existed. In order to assess whether the sound levels were SUfficiently high to impair the hearing of workmen a sound level survey of all major operations in the industry was carried out by the Mining Engineering Division of the Joint Coal Board.The results indicated ·that the operations could be classified into three categories of risk, probably hazardous, of doubtful hazard due to the intermittency of the operations, and of low hazard.Legislation has subsequently been enacted requiring the wearing of hearing preservation aids in some of the probable risk operations.

Jan 1, 1974

By Damian Connelly

The metallurgical heart of the majority of copper oxide processes is the heap leaching operation. Fresh low grade sulfide ores is a far greater challenge.The success of this unit operation is so important that operators need to understand the ramifications of their decisions or non-decisions and how they could affect the downstream processing. Heap leaching is an operation that can be described as a scientific art whereby principles of science can be used to guide experienced personnel in attaining their goals. Recent advances have been made based on better understanding the ore characteristics. The success of a heap leach operation, or otherwise, is dependent upon a number of factors, notably: The type of ore to be treated The extent of testwork completed to define the process The interpretation of the testwork results Ore preparation prior to stacking Agglomeration and curing requirements Other issues are: Compliance with the ’smaller’ requirements of environmental authorities Adequate and timely drainage of solution from the base of a leaching lift The degree of saturation in the pads Heap porosity – coarser or finer ore, which is better? Higher or lower irrigation rates – which would produce a better result? Laying out irrigation pipework for ease of operation and maintenance The addition of water, raffinate during agglomeration where needed The heap leaching of sulfide ores, including chalcopyrite, via enhanced bacterial leaching is discussed. INTRODUCTION Over the last twenty years, production of extremely pure copper from solvent extraction and electrowinning (SX/EW) has become more common in a market of real declining prices for copper metal. This paper touches on a number of heap leach operations and experiences. These projects were subjected to extensive engineering design and resulted in low capital cost, efficient operations with a number of lessons learned. The key to these operations was the performance of the heaps and associated fluid collection systems rather than the plants themselves.

Jan 1, 2019

The use of black and white and colour infrared film in remote sensing of natural resources is reviewed. In heavlly-forested areas such as New Zealand, the main value of the method is in surveying the vegetation cover to detect the existence of plant communities characteristic of specific geological formations. By contrast in arid areas of Australia where the vegetation cover is sparse and where rocks and soils are well exposed, the method can be used in detecting different rock types or other geological differences.

Jan 1, 1972

By Dale R. Ralston

This investigation was divided into two major phases. Phase I of the study was an examination of the occurrence and production of acid water within the Bunker Hill Mine in northern Idaho. The second phase of the project involved the study of water movement through an abandoned tailings pile. Mineralogy and hydrogeology were determined to be the two most important factors in the acid mine drainage problem. Low pH water was formed in the mine in areas of lead-zinc ore rich in pyrite. Water movement in the mine was important in the production of acid and the transportation of heavy metals. Areas of recharge to the mine were identified. A data collection network was installed to monitor water quality and quantity changes. The quantity of acid drainage from the mine was found to vary directly with surface runoff events. The study of the abandoned tailings pile was performed to determine the characteristics of water movement through the tailings material and the resultant impact on the hydrologic environment. The Page Tailings Pile, abandoned in 1969, was utilized as a study area. An extensive network of piezometers and meteorological data collection sites were installed in and near the pile. Data collected to date indicate the presence of a ground-water mound under the east half of the pile. Some transfer of ions from the tailings pile to the ground-water system has been detected.

Jan 1, 1973

By R G. Barker, A B. Christie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. More than 11 Moz of Au and 50 Moz of Ag have been produced from epithermal deposits in New Zealand, almost entirely from 50 deposits in the Hauraki goldfield. Since the 1980s, new deposits have been discovered at Waihi (Favona, Trio, Correnso) and nearby at Golden Cross. Feasibility studies into reopening the Talisman mine at Karangahake are continuing, and advanced projects with preliminary inferred resource estimates are reported at Wharekirauponga, Neavesville and Muirs. In the Taupo Volcanic Zone, 11 prospects have been drilled, resulting in the definition of large but low-grade Au-Ag resources at Ohakuri. In Northland, several Au, Ag and/or Hg prospects are known, and small quantities of Ag and Hg have been mined. Six prospects have had some drilling, with the most advanced exploration at Puhipuhi. The application of Taupo Volcanic Zone geothermal systems research to the modelling of former hydrothermal mineralising processes in some epithermal prospects has enabled better targeting of exploration.CITATION:Christie, A B and Barker, R G, 2015. Exploration for epithermal gold deposits in New Zealand, in Proceedings PACRIM 2015 Congress, pp 533–540 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By D Fergusson, J D. St George

Highwall stability is a major consideration in optimising opencast mine geometry. It involves assessing the risk of those slope failures that are large enough to have significant cost, safety and/or operational implications. These risks are then balanced against the value of the resource to arrive at an acceptable slope design. Load-deformation models (commonly referred to as ænumericalÆ models) of slopes provide a powerful tool in this decision-making process since they can be verified well before slope failure occurs. This gives the slope designer increased confidence in reviewing designs during excavation, potentially allowing early revision of pit geometry to either increase or decrease safety margins as appropriate. However, these models are not always adopted as they depend heavily on an appropriate choice of constitutive model and material parameters.   A preliminary load-deformation model of a 170m highwall in Solid Energy North (SEN) OperationsÆ Awaroa 4 opencast coal mine in the Rotowaro Coalfield has been prepared. This uses a strain-dependent constitutive model based on laboratory test results, strength parameters developed by SEN and excavation monitoring data. The laboratory testing has included triaxial compression tests on large-diameter fractured samples to characterise the stress-strain response of the closely-jointed soft rock masses that exist in many parts of the mine. Data from the monitoring of a 25m cut made during excavation of a haul road has been used to refine and verify the constitutive model. The resulting highwall model has predicted highwall crest movements corresponding to the excavation of each bench, for comparison with monitored values. Key model outputs are total horizontal movements of about 0.5m near the highwall crest and shear strains of 0.5-0.7% at the locations of potential bedding-parallel shear planes underlying the highwall. Most of the movement is expected to occur as creep rather than as an immediate response to excavation.

Jan 1, 2006

By P G. Gaylard

The minerals Industry carries out over US$ 2 billion of R&D annually. The R&D is performed at three levels ? in house research facilities; on a one-on-one basis with a research provider; as syndicated (collaborative) research. The key to a successful R&D programme is project selection. It is suggested that at this time of ?bounty? for the minerals industry the research portfolio should contain some ?blue sky? but potentially long term significantly beneficial projects. This said, the projects should align the technical concepts with the business imperatives. AMIRA has found the ?Road Map? concept has assisted in defining areas for R&D. Examples of this methodology using a Copper Road Map developed by AMIRA for the copper producers operating in South America is presented. The benefits derived from syndicated research are also discussed.

Jan 1, 2007

By P. K. Hofmeyr

Base Metal (Cu, Ni, Mo, Zn, Co etc.) analysis traditionally has been very slow in conventional analytical laboratories which can lead to additional costs being incurred in waiting time of drill rigs or mining excessively off-reef. Recent developments in the automation of analytical laboratories now allow for very rapid turn-around times for base metal analytical data which can help reduce such costs as well as reduce the unit costs of the analyses themselves. 2.0 CONVENTIONAL ANALYTICAL LABORATORY PRACTICE Conventional analytical laboratories are necessarily are very manual. Sample preparation is slow and laborious, samples are moved from stage to stage manually and, typically, all samples are processed in batches so a sample which is the first to be, say, milled has to wait for the complete milling of the batch before it advances to the next stage eg. mixed with wax prior to pelletising for XRF analysis. Inevitably this results in long sample data turn-around times for laboratories handling large numbers of samples. Manual sample preparation can only be accelerated by increasing staff which increases costs and can lead to additional errors being introduced. Cleaning of sample preparation equipment, eg. crushers and mills, between samples is essential to avoid cross-contamination between samples and this is slow and labour-intensive. In manual sample preparation the correct sample numbers staying with the samples is totally dependent on the efficiency of laboratory operators. It is extremely difficult to detect when errors have occurred due to the switching of sample numbers during the sample preparation stages. Running duplicates and QC samples at best is only partially successful in detecting when sample number switching errors have occurred. Errors of this nature and cross-contamination problems due to incomplete cleaning of sample preparation equipment tend to occur when laboratories are working at pressure due to high sample numbers and when supervisors are not present during 24/7 laboratory operations which is often required on plant process control laboratories. These problems are common to all conventional analytical laboratories and their magnitude is dependent on the level of control and efficiency of QC systems practised by individual laboratories. The disadvantages of conventional manual analytical laboratories can be summarized as follows:- 1. Labour-intensive which is costly especially when multiple shifts have to be used during 24/7 operations.

Jan 1, 2005

By David J. Kusler

This study is an appraisal of the feasibility of recovery and the possible chemical and physical uses of the limestone from the Greenbrier Formation in western West Virginia. Data on minability, occurrence, quality, and markets were obtained from published and unpublished sources and by a limited mail survey combined with personal contacts. The estimated costs of recovery by deep mining techniques are considerably higher than competitive surface and shallow subsurface operations. Compositional in formation available for this study was limited but indicated the suitability of the limestone for most physical uses and some chemical process uses in appraisal of the uses and demand reveals that immediate markets may be difficult to establish, but for some uses long-term prospects may be encouraging, especially if the quality of limestone would be suitable for lime manufacture or use as metallurgical fluxstone.

Jan 1, 1968

By Jacek B. Stypulkowski

This paper discusses the challenges faced by the design team of the under-river crossings of electric transmission feeders in New York City, a densely populated urban area. The under-river crossing of a 345 kV feeder was initially designed as Horizontal Directional Drilling (HDD), but was redesigned as a utility tunnel because of site con¬straints on both sides of the river. Multiple studies addressed location, available tech-nologies and costs. Multiple soil investigation phases addressed design aspects of HDD, as well as tunneling. Contractual issues varied from a design build alternative with Geotechnical Data Report (GDR) to design tender approach with GDR & Geotechnical Baseline Report (GBR).

By Kevin M. Connor, O&apos

This report documents-the process of literature review, site selection, instrument installation, data acquisition, and preliminary data reduction performed to evaluate the influence of rock mass discontinuities on coal mine subsidence. A system of surface, subsurface and mine level instrumentation was installed at the Armco No. 7 Mine in Montcoal, West Virginia where the overburden varied in thickness from 630 to 1040 feet. Survey monuments, borehole pressure cells, full profile borehole inclinometer-extensometers, mine level extensometers, stressmeters and tape extensometer convergence stations were installed to monitor displacements and stress changes. Final design of the instrumentation system was based on: a) review of available information, b) field mapping and analysis of areal photography, c) drilling, and d) borehole geophysics. The report contains the complete graphed data of stress and displacements accompanying the longwall mining of a 4800 ft long by 480 ft wide coal panel.

Jan 1, 1983

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By André Desbiens, Jocelyn Bouchard, René del Villar

"The metallurgical performance of the column flotation process is determined by the concentrate grade and recovery. Although the former can be continuously measured using an on-stream analyzer, the latter must be estimated by a material balance calculation based on seldom verified steady-state assumptions. Consequently, the automatic control and optimization of flotation columns should be performed using secondary variables having a strong influence on the metallurgical performance, such as froth depth, gas hold-up or bubble surface area flux and bias. The aim of this paper is to present a model-based automatic control strategy using froth depth and bias measurements obtained from virtual sensors developed at Laval University. Preliminary pilot plant results on two-phase (water– air) and three-phase system (water – minerals – air) will be presented and eventual industrial implementation of such a strategy as well as the possibility of achieving effective real-time optimization from bias and froth depth measurements will also be discussed.INTRODUCTIONFlotation columns have been widely studied and used in mineral processing for about twenty years. Although a great deal of work has been accomplished to understand the influence of different variables such as froth depth (H), bubble surface area flux (Sb) and bias (Jb) on the metallurgical performance, the measurement of some of these variables is still difficult to be performed – except at the laboratory level – because in most cases, no commercial device yet exists.As a result of this, it is almost impossible to achieve neither efficient control nor optimization of the process at the industrial level, even in open-loop operation. This paper aims at presenting a simple control strategy of froth depth and bias. Description of the sensors used to achieved measurements, preliminary pilot plant results for froth depth control, eventual industrial applications and possibilities for process optimization are also treated."

Jan 1, 2003

By Joseph L. Margin

From a stubborn start to record setting performances in little over a year, that is the story of the English Running Tunnel Boring Machines. The program to transfer technical information on these highly advanced machines from builder to user will be discussed as a vital link to this accomplishment. Some interesting features of these machines will be covered as well as a recounting of the various conditions that were encountered during these drives and how they were resolved.

Jan 1, 1991

By K. A. Grace

K.A. Grace's article advocates usage of the terms describing resources as defined by the US Bureau of Mines (USBM) and the US Geological Survey (USGS). Originally recommended in 1943, the terms were revised in 1976 and again in 1980. Mr. Grace further recommends that the term reserves should be severely restricted and that it should encompass mining and processing factors. The list of references quoted in the article does not, however, mention the study concerning reserves that was made over a period of almost four years by a joint Committee on Definitions. This committee was sponsored by three societies - the American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME), the Society of Economic Geologists (SEG), and the American Institute of Professional Geologists (AIPG). Most of the detailed work was done by a working party appointed by the Society of Mining Engineers (SME) of AIME. After studying previous definitions in the US as well as in the United Kingdom, Canada, Australia, France, and other European countries, the following definitions were proposed and accepted in 1974 by the SME board of directors. (Ore reserve definitions in Rhodesia, South Africa, or New Zealand were not mentioned as having been reviewed.) Table 1 lists definitions from MINING ENGINEERING, July 1975. Notice in Table 1 it was mentioned, under Resources, that the definitions of reserves were recommended for the purposes of commercial evaluation. It was further stated that the terminology adopted by the USBM and the USGS, as released to the public, covering resources, was recognized as such. Mr. Grace also recommends that reserve calculations should allow for future losses in ore tonnage, ore grade, milling, and smelting. Unfortunately, it might take years to develop a prospect after it has been discovered. Mining methods have to be tested before being finalized in order to know what tonnage of ore is going to be lost, or how much dilution is likely to occur. The same problems are present in concentrating or in smelting. Operating mines usually know how mined grade compares with ore reserve grade. They can usually predict fairly closely what their final metal recoveries are probably going to be. It is, however, expecting too much to have to delay quoting reserves from say a recently drilled prospect. Any responsible mining geologist or mining engineer (or company for that matter) should state several things about an ore reserve calculation: that it is or is not a preliminary estimate only; that estimated grades have not been diluted to allow for a future, as yet unknown, mining method; that metal recoveries are or are not only tentative, based perhaps on drill hole samples only or on no metallurgical testing at all. Reserves of a partially explored prospect are always quoted when it becomes necessary to raise capital. If they are described as preliminary only (really just tonnage and grade estimates and not true "reserves") in addition to being accompanied by some of the items just mentioned, nobody is going to be misled. If, on the other hand, a report by a member of the SME or SEG is intentionally misleading, the individual must be reported and eventually disbarred from his or her society. To summarize, let us stay with the definitions of ore, ore reserves, and related terms as recommended and accepted by SME. I might add that on occasion I have used a fourth category in my ore reserve calculations, namely Geologically Possible Ore. This category is more or less the same as Inferred ore defined by the USBM and USGS. I have never given a grade to this category, which may be based only on geological mapping, geochemical sampling, or geophysical traversing.

Jan 8, 1985

AQUILA Mining Systems Ltd., designs, develops and delivers systems for measurement, analysis, simulation, control and automation to the mining, construction and petroleum industries. The objective of current efforts by AQUILA is the continued development and refinement of computerbased systems and techniques to automatically process monitored performance data from surface blasthole drills and mining shovels, and the management and coordination of these pieces of equipment by GPS (Global Positioning Systems).

Jan 1, 1994

Let’s start off with your assessment of the mining industry. Today, the status of the mining industry is stronger than it has been over the previous few years. While mining continues to be a major part of the world’s economic foundation, the industry is gaining strength due to rebounding metals and minerals prices. And now, with these rising prices and the changes the industry instituted during the years when mining-related commodities were selling at low prices, our stronger, more productive and internationally competitive industry should flourish. Mining remains an essential business and the industry is far ahead of the game when it comes to the trend of globalization as a key to sustained growth. Also, the industry continues to realize increased productivity through technological innovations. And an increasing number of countries are moving towards capitalism, which opens doors for exploration and mining within their borders. After looking at all of these factors, I believe that the mining industry will only continue to gain momentum in the future.

Jan 1, 2004