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By Xintan Chang

MFIRE is a computer simulation program that performs normal ventilation network planning calculations and dynamic transient-state simulation of ventilation networks under a variety of conditions. The program is useful for the analysis of ventilation networks under the influence of natural ventilation, fans, fires, or any combination of these. MFIRE simulates a mine's ventilation system and its response to altered ventilation parameters such as the development of new mine workings or changes in ventilation control structures, external influences (varying outside temperatures), and internal influences (fires). Extensive output enables detailed, quantitative analysis of the effects that the alteration will cause to the ventilation system. The program was developed at Michigan Technological University (MTU), Houghton, MI, with support from the Bureau of Mines. A personal computer (PC) version of the program was completed under contract for the Bureau by MTU. The purpose of this report is to document the installation and use of the PC version of the program MFIRE.

Jan 1, 1990

By Rogerio Castejón

The evolution on the computer in the last 10 years have caused a big change on the way the mining companies are doing exploration. The following factors have contributed to that change: the downgrade of computers and software cost associated with the “usability” (easy of use) of the present systems (remember the old DOS and UNIX systems). New systems are more focused on the users rather than on the experts in applications, meaning that the geologist must understand geology and not operational system, programming, etc. Market conditions requires exploration to be faster and more intelligent than in the “old” times, and companies are always demanding quicker answers from their geologist group as well as lower exploration budgets. Exploration teams must be more effective and efficient. In this sense, the only way to achieve those requirements is to use the proper techniques, methods and tools on the diverse stages of exploration. Its necessary to consider that the costs of data acquisition increase, almost exponentially, through the stages of exploration, from grass roots to advanced stage.

Aug 25, 2002

By James W. Reil

A test series of small, precisely-controlled and thoroughly-monitored production blasts was conducted at two quarries. In each series, all variables except delay were kept constant, as much as practically possible. The first aim of the study was to determine the effect of local geology on ground vibration. The second aim was to test several hypotheses relating the effect of millisecond delay intervals to fragmentation and ground vibration. A resonant frequency of ground vibration was shown to be related to the thickness of the overburden, in accord with a model proposed by Gupta (1961). Since the overburden geology creating this resonant vibration cannot usually be changed, two methods were tested to choose delays such that blast vibrations would destructively interfere. These were shown to be effective in modifying both the peak particle velocity and response spectra of ground vibration. The delay interval chosen also affects fragmentation, primarily in massive rock, with an optimum relief between holes of 2 ms/ft. Strain gage records indicate a possible mechanism consistent with this information.

Jan 1, 1985

By Carlos F. Perucca

"Potassium is one of the three basic plant nutrients along with nitrogen and phosphorus. There is no substitute for potassium compounds in agriculture; they are essential to maintain and expand food production.Potash is extracted from buried ancient evaporites by underground or solution mining. This accounts for most of the potassium produced. Another important source is brine from landlocked water bodies, such as the Dead Sea, Salar de Atacama or Great Salt Lake.About 95% of potash produced worldwide is used in agriculture. The rest is found in several other industrial uses, including glass manufacturing, soaps, plastics and pharmaceuticals.Currently, three producers: IMC, PCS and Agrium operate 8 conventional and two solution mines in Saskatchewan, five of which run froth flotation circuits, two heavy media-flotation, two run forced crystallization and one natural crystallization.Potash in SaskatchewanPotash was discovered in Saskatchewan in the early 1940’s while drilling for oil. The deposits lie diagonally across the southern plains of Saskatchewan sloping southerly from a 1,000m depth at Saskatoon to more than 1,600 m depth at Belle Plaine and up to 3,000 m in depth in North Dakota. The known deposits are massive, accounting for more than 40% of the world’s known reserves."

Jan 1, 2003

The plant and processing site at Porgera has been built on a levelled mudstone ridge about lkm E of the mine. Excavation of 7xl06m3 of soil and rock was necessary to achieve the required area. The exposed mudstone belongs to the Chico Formation and is weak, sheared and readily breaks down by slaking upon exposure. Tectonic uplift and subsequent erosion have produced the present landscape of narrow bedrock ridges, with deep colluvium in the incised valleys. The deep excavation to a maximum of 60m, has rapidly unloaded the mudstone, and subsequent stress relief has caused rebound and dilation of the material. The processes of pore pressure equilibration, softening, progressive failure and loosening, combine to deteriorate the newly exposed rock mass. These processes are commonly associated with pre-existing shear surfaces, fissures and a

Jan 1, 1991

By John M. Gordon

DURING and after 1949, various groups of British mining engineers came to the Dominion Coal Company, Limited, at Sydney, N .S., to see at first hand the Dosco MINER ( 1). These visits culminated in 1952 with the ordering of four Dosco Miners by the (British) National Coal Board on an experimental basis through their Experimental Expenditure Funds. Others are now on order. The first machine was delivered in February, 1953, and, after slight alterations to suit the different power supply, the machine was made ready to work. Due mainly to the size of the machine, new rules and regulations governing its operation had to be put into effect and it was not until April, 1954, that the machine was put underground. It started to produce in June of that year. The three others were delivered early in 1955. The authors were sent to England by the Dominion Coal Company to install and demonstrate these machines and to work with the Coal Board engineers to- further interest in the machines in the British coal fields .

Jan 1, 1956

By S. Ndlovu, M. Malatse

"The Witwatersrand Basin is the heart of South Africa’a gold mining industry. The cluster of gold mines located in the Witwatersrand Basin generates a significant amount of mine tailings, which have adverse effects on the environment and ecological systems. In addition, disposal costs are very high. The exponential population growth in the Witwatersrand area has resulted in pressure on the reserves of traditional building materials. Quarrying for natural construction material is very expensive and damages the landscape. This work therefore examines the use of gold mine tailings in the production of bricks.Different mixing ratios of gold tailings, cement, and water were used. The resulting bricks were then cured in three different environments - sun dried, oven dried at 360°C, and cured in water for 24 hours. The bricks were then tested for unconfined compressive strength, water absorption, and weight loss. The results showed that the mixture with more cement than tailings had a compressive strength of approximately 530 kN/m2. It was also found that the best brick curing system was in a water environment. Bricks made from tailings cost more than conventional bricks because of the higher quantity of cement used, but the manufacturing process consumes less water. Overall, the results indicated that gold mine tailings have a high potential to substitute for the natural materials currently used in brickmaking.Paper written on project work carried out in partial fulfilment of BSc. Eng. (Metallurgyand Materials Sciences)"

Jan 1, 2015

By H He, S Tillotson, S Gibbons, J Shaw

"Water evaluation and management during mining exploration and operational activities is crucial to minimise direct and indirect operational costs and also in delivering mining companies the less tangible, but equally critical æsocial license to operateÆ.Mining is often carried out in remote areas, where the mine will be the most significant and visible user and potential contaminator of water resources. However, wherever it is located, a mineÆs use of water must be managed in the context of two key aspects: the natural parameters of the resource; its abundance, its temporal variability and its chemical and physical qualities other users of the resource; other industry, potable water supplies and ecological requirements of local habitats.It is vital, therefore, that this commodity be assessed to an appropriate degree to help establish the viability and sustainability of the mining project and identify those other stakeholders who may be affected by the mining companyÆs activities.This paper outlines the background to catchment-scale model and presents a cost-effective method for establishing a robust water baseline and creating a water management tool to be used throughout whole mine life cycle. Numerical surface and groundwater modelling has long been established as a tool for reactive management, following collation of yearsÆ worth of data. Now, using freely available remote sensing data and desk study information, analytical modelling techniques can be used cost effectively to provide mining companies with a tool for assessing and managing their water consumption requirements at the outset of a new project venture.The paper includes a selection of case studies to show how the use of analytical modelling can be used as an evaluation and management tool to help not only assess general watershed parameters and water availability but also how it can be used as a tool to provide decision makers with the information to complete æwhat if?Æ scenario assessments. The case studies illustrate how a combined hydrological and hydrogeological model may enable identification of sensitive receptors, water competition issues and contaminant migration pathways to help manage the risks associated with water consumption and its potential contamination from exploration and operational activities.CITATION:Gibbons, S, Shaw, J, Tillotson, S and He, H, 2013. Catchment-scale water modelling and its role in risk management during mining exploration, in Proceedings Water in Mining 2013, pp 175-188 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By Oliver Bowles

The United States Bureau of Mines has within its ranks a group of engi- neers who are engaged in working out quarry problems, the solution of which will be of general benefit to the industries involved. The problems undertaken are approached in a systematic and thorough manner, all the evidence for and against any proposed change or new development being collected as carefully as an attor- ney would prepare his data on an important case. Unlike the attorney, however, the Bureau engineer does not take sides; his judgment is based entirely and in- partially on the array of facts presented. In order to gain the desired infor- mation he visits many plants, consults with the leaders in the industry, works out experiments in his laboratory, and supplements this information with a stu- dy of all available literature already published on the subject in any part of the world. As an engineer who has for eight years conducted such inquiries in the stone industry, I propose to discuss the Bureau of Mines viewpoint; and it may be of interest to consider with me in a brief and general way the engineer's method of looking at quarry problems, and some of the results attained through past and present labors. While the Bureau has conducted no investigation directly for the crushed- st one industries, two years of investigative work at cement-plant quarries, and work now being conducted at lire-plant quarries, has a very direct bearing on the problems of the crushed-stone industry, since stripping, drilling, blasting, loading, and transportation are similar in many respects in all stone quarries. The results of cement-plant quarry investigations are to be found in Bureau of Mines Bulletin #160. (b) Two short papers on lime-plant quarry problems have been issued in mimeographed form as Serial #01 (c) and Serial 3 (d).

Jan 1, 1923

By B Watson

The ConSep ACACIA Reactor is a device, which utilises a high intensity cyanidation process to achieve very high, usually near total, recovery of gold from gravity concentrates. The process utilises a fluidised bed and a chemical oxidant to enhance the gold dissolution kinetics to the point where the bulk of the dissolution occurs in a few hours. For convenience and security, most plants operate a 24-hour turn around. The product from the process is in the form of cathode gold ready for smelting by traditional means. The ConSep ACACIA Reactor performs a two-fold role. Firstly it increases gravity gold production, leading to a decreased CIP feed grade. Secondly, it removes slow leaching components from the plant leaching circuit. This two fold benefit leads to the following efficiencies: enhancement of the dissolution kinetics; enhancement of the adsorption kinetics; reduction of the gold load reporting to the carbon; a significant reduction of the ægold in circuitÆ lockup; and removal of slow leaching entities which can also result in a lowering of the required cyanide concentrations in the leaching circuit and a subsequent reduction in overall cyanide consumption. The above benefits are discussed in this paper, with a particular focus on the ConSep ACACIA ReactorÆs role in removing slow leaching components, with data generated over a 21-month period. Improvement in overall plant recovery via removal of slow leaching gold species is achieved in two ways. Firstly, some of the slow leaching entities, successfully leached under intensive cyanidation, are not always fully leached under plant conditions. This results in a lowering of the solid tailing. Secondly, the faster leaching kinetics achieved in the plant as a result of the removal of slow leaching entities results in faster and more complete adsorption of the dissolved gold onto activated carbon. This results in a lowering of the solution tailings. The construction and operation of the ConSep ACACIA Reactor is simple. Apart from the reactor body, which is a proprietary design, all components of the system are æoff the shelfÆ or specific to the siteÆs requirements. In operation of the fully automated version, a PLC controls a series of valves and pumps but except for a daily changeover process the only operating component for the bulk of the time is a relatively small solution pump. The process can be totally automated giving the security of a æhands freeÆ concentrate handling process up to the point where the product is presented as cathode gold. The ConSep ACACIA Reactor was developed by Anglogold Australia (formerly Acacia Resources) for Union ReefÆs Gold Plant and has been in production since February 1999. It has proven to be a low cost, high recovery, mechanically reliable method for the processing of gold concentrates. Such has been the success of the plant, as of June 2003 there are eighteen full installations of the processing plant installed at mines owned and/or managed by Anglogold, Newmont, Placer Dome, Independence (formerly Lonrho), Sons of Gwalia and Harmony.

Jan 1, 2003

By L. Nichols, H. Keele, K. Czajewski

"The oil sands industry in northern Alberta disposes of the by-products of bitumen extraction into tailings ponds. The mix of tailings sand and mature fines, with gypsum added as a flocculent, constitute a waste stream called consolidated tailings or composite tails (CT). The two main challenges of the tailings disposal process are a chronic shortage of economical containment and the potential mobility of CT deposits in the event of breaching by, for example, long-term erosion, which makes abandonment of tailings ponds more complicated. Thick deposits of CT do not consolidate in adequate time to provide reassurance for abandonment of the CT containment facilities and that is why the containment must be adequately robust or the properties of CT improved for long-term stability. This paper addresses potential solutions to these problems by applying the gravity drainage of CT and quasi-homogeneous construction for containment facilities.Gravity drainage is suggested as a mechanism to facilitate the consolidation of CT in critical areas of the ponds by inserting internal sand layers within the body of the deposit. Critical CT areas are defined as areas around the perimeter of containment. The advantages of this solution are longterm stability of the disposal area by creation of stiff deposits around its perimeter and facilitation of reclamation efforts on its surface.The present solution for containment of CT deposits is not favourable from a materials balance point of view. In general, sand has become a valuable resource as it both forms the primary component of the CT matrix and becomes the containment building material. If sand is required for CT, less is available for dyke construction. This puts additional pressure on the industry as a whole to maximize the use of overburden and interburden for construction of tailings containment structures. Typically, only 50 percent of dry mine waste (overburden + interburden) is incorporated into dyke construction. The remainder of dry waste is stored either in waste dumps or in tailings ponds, consuming valuable in-pond space originally allocated to CT material. Quasi-homogeneous dykes are proposed to contain CT deposits rather than traditional minimum cross-section dykes built of overburden and/or cell sand. The quasi-homogeneous dyke may change the unfavourable material balance and lessen the construction constraints that are presently imposed on the mine/waste disposal process."

Jan 1, 2008

By H. T. Ozkahraman

It is important to know the breakage mechanism in materials since this knowledge influences the results of subsequent grinding operations. There are two distinct failure mechanisms in breakage: one is tensile micro crack generation at low stresses, which leads to macroscopic failure by disintegration, and the other is formation of shear zones under heavier dynamic impact forces, which generates more fines as seen in crush zones in blasting. Tensile fracturing simply breaks the material into fragments. It is seen as the disintegration of the specimen into two or more separate fragments. This happens under the absence of lateral stresses and the material is free to expand. On the other hand, compressive-shear breakage produces finer fragments due to shear stresses. The first mechanism is observed in laboratory tensile and bending strength tests and the second mechanism is observed both in laboratory brittleness tests and in situ blasting operations under dynamic impact forces. The friability of rocks and ores can be determined by a brittleness test. A test apparatus to determine the friability value has been designed to suit limestone strength characteristics used in cement production. The friability and stored strain energy values of barite, marble, limestone and bauxite have been determined and compared with the corresponding Bond work index (Wi) and grindability index (G) of these materials. The physico-mechanical properties of the tested materials have also been determined to investigate their effect on friability and grinding. The relationships obtained between the indices were in surprisingly good agreement, with high correlations (0.99 and 0.97). The Bond work index and grindability index can therefore be estimated from the friability value, which can be determined more rapidly than the Bond test. But for certain rock types such as andesites the relationships does not hold. Key words: comminution, tensile stress, shear forces, brittleness test, strain energy.

Jan 1, 2010

By Walter Smith

Environmental Quality Committee ?EQC was created in 1995 to facilitate dialogue between industry and northern communities and help build the understanding of the industry in those communities. ?EQC is made up of representatives from 32 northern communities. ?Meet regularly with Cameco to discuss on going and new projects. ?Tour mine sites on a yearly basis.

Nov 1, 2011

By George W. Toth

Uranium in situ leach mining has recently emerged as a viable alternative to conventional miring techniques. The cost implications of in situ mining are therefore of increasing interest to mining paracticioners as well as public officials. This report presents the results of an assessment of uranium in situ leach mining costs through the application of process engineering and discounted cash flow analysis procedures. A computerized wasting technique, termed a cost model, was developed through this effort to facilitate rapid cost analyses. Application of this cost model will generate mine life capital and operating costs as well as solve for economic production cost/lb. U308. Conversely rate of return may be determined subject to a known selling price. The data bases of the cost made! have been designed to reflect variations in Texas vs. Wyoming site applications. The results If applying the model under numerous ore deposit, operating, wellfield and extraction plant conditions for Texas and Wyoming are summarized in the report. Sensitivity analysis of changes in key project parameters have also been tested and reported.

Jan 1, 1981

By Anthony Iannacchione

Coal mine bursts have represented a major hazard for U.S. mining operations for more than 90 years. During this time, many prevention controls have been developed and tested. This paper reviews 11 prevention control techniques. Although coal mine bursts are not common events in most underground coal mines, their occurrence almost always requires a change in mining practice. Over the many years of dealing with these hazards, specialized requirements for layouts and novel extraction sequences have been developed on a site specific basis. The keys to mitigating risks are to properly assess the coal burst hazards and to possess the knowledge and skills to prevent or remediate their occurrence.

Jan 1, 2008

By Hirst H, McAfee J

In December, 1934, Mr. R. Sussex extruded some silver lead alloy wires in order to determine their electrical resistance. After the determinations had been made each wire was threaded through a sheet of paper on which the composition was noted. The wires were placed in a more or less tangled mass in a cupboard in March, 1935. It was not until September, 1936, that they were re-examined, and it was found that during the eighteen months some of the wires had corroded very badly. It was not until March, 1938, that the wires and the corrosion product could be examined, and the results are given in the following pages. It is of interest to note that none of the numerous silver-lead alloys which have been used for creep testing in the rolled condition have shown a similarphenomenon. The silver content of the rolled alloys was, however, never greater than 0·1%.GENERAL APPEARANCE OF THE CORRODED WIRESThe wires contained 0·1% up to 28% of silver, and a general examination showed that the corrosion had progressed farther the higher the silver content. This can be seen in Fig. 1, which is a photograph taken in March, 1938, of typical wires at a 'magnification of five diameters. In the early stages the corrosive action seems to be localized and an area of grey, yellow or reddish brown powder appears. The grey corrosion product is by far the one, most frequently seen, and in the later stages the only one visible from the outside. The reddish coloured product is sometimes seen on the residual metallic centre when the grey product has been broken away.The irregular extent of the corrosion can be seen in Fig. 2, which shows (natural size) the 5% silver wire after standing two years. The corroded parts are seen to be much thicker than the slightly corroded ones. The corrosion product, being non-metallic, is quite brittle and falls away from the wire on bending. In the extreme case the' whole wire has corroded and presents a cracked appearance as seen in Fig. 1 (281% silver).An approximate idea of the extent of corrosion can be obtained by measuring the diameter of the corroded part. The original diameter in each case was ·050/ ·051 inches and in Table I are given the diameters of the corroded parts after Hand 3 years respectively. When the diameter...

Jan 1, 1941

By Shreyas Giridharan, Fursan Hamad, Sujith Gowda, Christian Moormann

"Pile installation in soil is a dynamic process which exhibits large deformation in the soil region. Experimental investigation of pile installation is both time and resource intensive. Numerical investigation can be a helpful tool for the analysis of the installation process. Furthermore, numerical analysis allows simulating various soils and loading conditions with ease. Finite Element Method (FEM) – a widely used framework for numerical simulations - fails to perform well for soil mechanics where large deformation and heavy material movement exists. In order to alleviate this shortcoming, Material Point Method (MPM), advancement to FEM has been used. In MPM, material points (particles) are used to represent the domain which carry the information and move over a fixed computational mesh where the governing equations are solved.In the present work, a variation of MPM, called CPDI (Convected Particle Domain Interpolation) is utilised which handles large deformation problems better than the classical MPM. Here, the material points are represented by a spatial domain which deforms according to the particle deformation. This eliminates stress oscillations while particles cross the grids. Implementation is validated and applied to pile installation in dry and saturated soil conditions. A 2D axisymmetric model is chosen, with penalty function method being used for evaluating contact between soil and pile. Sand is modelled via the hypoplastic constitutive description that takes into account large deformation, as well as small strain stiffness. From these simulations, various parameters like stress, void ratio and friction angle are studied.INTRODUCTIONOffshore piling is challenging in terms of testing and execution. Before the execution, predicting an efficient installation method requires study of various parameters, like soil conditions, type of loading, force requirement etc., and are the minimum parameters to be known beforehand. To obtain these parameters, testing a real scale prototype under different conditions is not feasible. Scaled model tests in lab can support in making certain decisions, but fail to replicate real behavior fully. Therefore, the need for a numerical simulation technique emerges, which can provide early predictions easily and accurately. This later can be extended to real scale tests, reducing the number of experimental investigation required.Simulation of displacement pile installation in sand involves large deformation due to penetration process, thereby making the application of FEM impossible, where large deformation causes heavy mesh distortions. Due to this, meshless methods are developed to treat large deformation in a better way. Among various meshless methods, Material Point Method (MPM) shows more applicability to geomechanical problems. This is mainly due to the ease of handling soil, structure and water in a unified manner."

Jan 1, 2017

By Francisco Sena Leite, Pedro Brito, Auã Kiahla, Raquel Carvalhinha, Tomi Kouvonen, Vinicius Miranda

Shockwaves that generate vibration in the surrounding environment of a blast, are one of the most important factors to control drill & blasting works near delicate buildings as well as in sensitive structures (wall control). On top of the damage to the buildings themselves, sensitive equipment such as computers, measurement apparatus and medical devices can be also compromised. The most commonly measured values from vibration are PPV (peak particle velocity), acceleration and displacement. Some devices and techniques have been developed in the last decades to measure the impacts of these vibratory phenomena. This information can be used to predict levels of vibration for future blasts and improve their quality of design using the attenuation law. From traditional studies to modern seismographs, a range of solutions are used for this propose. The main problem of applying this kind of technology is the high cost associated with each measurement device. In order to measure the ground vibration using new technologies while lowering the cost, a device has been developed using a microcontroller and electronic sensors commonly found on the market. This new equipment was tested side by side with traditional seismographs and the results were sent to a server for analysis. After several blasts, the necessary data was generated for the validation of the prototype. Through numerical mathematical processing (Taylor’s approach and numerical derivation) the original data supplied by the accelerometer’s sensors was transformed into velocity and, after the data mining, a statistics residue analysis was applied in order to evaluate if the data from the prototype and from the traditional seismographs were similar. The data from each system was used to estimate the attenuation law and the results are shown in this paper.

By Steve Kral

When the price of gold cracked the US$9.60/g(US$300/oz) mark last year, the gold-mining industry began to crank up again. This followed several years of gold prices that had languished in the mid-200s. Existing mines increased production and mines that had lain dormant for many years were getting second looks. The United States still produces a large amount of gold. But not much of the new production is coming from that country. Instead, strict environmental regulations still have companies wary of trying to invest the millions needed to start a new mine or expand existing ones. And after years of studies and negotiations between legislators, environmental interests and the mining industry, the United States still has not crafted a new mining law.

Jan 1, 2003

By Dave Marsh, John Goode, Niels Verbaan, Kevin Bradley, Henrie Notzl

The mineralogy of the Avalon Nechalacho deposit is complex with significant fractions of HREEs, Zr, and Nb found in refractory minerals such as zircon and fergusonite. Sulphuric acid baking followed by water leaching can be used to extract REEs from flotation concentrates, but acid baking does not completely "crack" the zircon and fergusonite, so the extractions of Zr, Nb, and HREEs are not high. An alternative flowsheet has been developed that is able to obtain significantly improved extractions of HREEs, Zr, and Nb from flotation concentrates or acid bake residues. This is accomplished by cracking the zircon and fergusonite minerals with caustic soda at high temperatures, followed by water washing to recover excess caustic soda and soluble sodium silicates and phosphates. REEs, Zr, and Nb in the solid residue can then be solubilized with HCl or H2SO4. This paper highlights some of the findings from an extensive laboratory program and discusses several flowsheet implications.

Jan 1, 2014