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By N. A. Pace

This is one of a series of papers being published by the Federal Bureau of Mines for the dissemination of information on methods and practices used in the mining and preparation of crushed stone for market requirements. Performance in terms of units of work or tons produced per machine and per operator man-hour are given whenever that information is available. Direct operating costs are useful for comparing different methods, and are, therefore, included if possible. In addition to the factual description of equipment and methods used, it is desirable to discuss the engineering reasons for the choices that have been made. This paper is particularly concerned with the opertions at the Columbia plant of Palmetto Quarries Co. of Columbia, S.C. The plant is about one-half mile east of the Congaree River and adjacent to the southwest corner of the city of Columbia. Rail access is by the Atlantic Coast Line Railroad, and by a spur strack of the Seaboard Airline Railroad.

Jan 1, 1962

By Laura Mottola

Process Design and Change Management for Successful Deployment of Technology in Mining Over the last 30 years Canada has been successful in developing but not deploying hardrockmining automation. Our opinion is that the current lack of R&D investment and implementation capacity places Canada at risk as a future global mining leader A white elephant A burdensome possession; creating more trouble than it is worth. White (albino) elephants were regarded as holy in ancient times in Thailand and other Asian countries. Keeping a white elephant was a very expensive undertaking, since the owner had to provide the elephant with special food and provide access for people who wanted to worship it. If a Thai King became dissatisfied with a subordinate, he would give him a white elephant. The gift would, in most cases, ruin the recipient.

May 1, 2010

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

By C. A. Jeffrey

The Dirtlow Rake vein deposit, which is up to 12 m thick, contains a range of paragenetically linked replacement mineralisation styles typical of many Mississippi Valley-type deposit environments. The main ore zone lies within the solution collapse breccia domes, the more southerly of which has recently been well exposed, allowing its relationship to the associated mineral-hosting structures to be studied. The domes were largely formed during early silicification, propagated by dissolution collapse and infilled by subsequent fluorite-barite mineralisation. The location of pipes and pervasive replacement was also controlled by early silicification. Structurally controlled bow tie shears were formed as a result of fluid access at fracture-bedding plane intersections. The nature and distribution of the mineralisation styles indicate that the degree of fluid access, residence time of solutions in contact with the wallrock and susceptibility of the limestone to silicification each played a major role in dictating mineralisation

Jun 19, 1905

Support design in jointed or blocky rock masses is often approached by the use of either 'rules of thumb', rock mass classification systems such as the Q-system (Barton, Lien and Lunde, 1974) or RMR (Bieniawski, 1973) or conventional wedge analysis. Generally, this requires that a number of key simplifying assumptions are made and the support system is designed to cater for either a mean, most likely, or worst case scenario depending on the risk tolerance. The design block size is often a major uncertainty and often a worst case block size based on excavation span is used. Thompson and Windsor (2007) state that it is inappropriate to base support designs on the excavation size as these size blocks rarely occur if discontinuity trace lengths are considered. Probabilistic keyblock methods can be used to determine the most likely design block sizes. A methodology is presented whereby JBlock software (Estherhuizen, 1996) is used to estimate potential block sizes as part of the support design process. Using information such as the spacing, orientation and length of discontinuities, it is possible to simulate blocks in the walls of an excavation (Esterhuizen and Streuders, 1998). Keyblock analysis methods (Goodman and Shi, 1985) are used to evaluate whether blocks are removable and whether the chosen support will be sufficient to ensure stability. Data from two mines is used to demonstrate how probabilistic keyblock analyses can be used in support design. Discontinuity data was used to generate 10 000 removable blocks and the design block size statistics were determined. For one mine this information was used to scale blocks in a conventional. Unwedge analysis whilst for the other mine, the point estimate method (Harr, 1987) was applied. The choice of appropriate design acceptance criteria in terms of factor of safety and probability of failure is also considered.

Nov 25, 2010

By M. A. Raza

Cable shovels are capital-expensive and primary production equipment in many surface mines. The forces acting on the shovel dipper vary as the dipper moves through the muck-pile. The variations in the forces cause stress loading of the components of shovel and dipper resulting in unplanned downtimes, reduced shovel efficiency, and high mining costs. A potential solution to the above problems is the deployment of an intelligent shovel excavation (ISE) technology, with real-time formation identification, recording, and knowledge transmission capabilities. This research advances the ISE technology by developing dynamic model of cable shovel dipper using Newton-Euler techniques. The model includes the dynamic cutting and dynamic weight forces acting on the dipper as it moves through the muck-pile.

Jan 1, 2011

By A. W. Bester

Paper written on project work carried out in partial fulfilment of B. Eng. (Mining Eng.) Cullinan Diamond Mine currently handles 3.2 million tons of run of ore per annum. This is done by means of an underground train system, which is located at 763 metre level. Four trains, one in each quarter of the pipe, collect ore from passes and transport it to centrally located tips in the north and south of the pipe. The ore is then split into coarse and fine fractions. The coarse fraction proceeds to the primary crushers in the north and south. Historically, mining has been performed in such a manner that an equal amount of ore has reported to each quarter of the pipe. However, the tonnage profile of the mine will change such that the ore will no longer be split equally. For approximately five years the majority of ore will report to the east and thereafter most of the ore will report to the western portion of the mine. This will continue for the remainder of the current infrastructure level?s operational life. Coupled with this is the fact that the mine is aiming to increase its annual production to 3.8 million tons. The result is that the current ground handling system cannot accommodate the additional tons and therefore alternative ground handling options have been investigated. The continued existence of Cullinan Diamond Mine relies on finding a system that can economically handle the additional tonnage. Three options were investigated. Firstly, a train option, which would be an upgrade of the current system, was investigated. Two truck options were also investigated, the first of which was a conventional truck option. The second truck option was more interesting and involved an unfamiliar Combi truck system. The truck options were investigated primarily due to the fact that the block height of the BA West (a new production block) can be increased by 15 meters if a truck option is decided upon. This would create a significant increase in revenue for the BA West project. Each of the options was assessed in terms of its physical and financial feasibility. In terms of the physical constraints, it was found that all three systems could work. Detailed financial analysis indicated that either of the two truck options would be a suitable solution. However, due to the limited information regarding the Combi truck option, it should be further investigated. This applies particularly to the actual running and maintenance costs for the equipment.

Jan 1, 2005

By G. C. Smith

Process control applications in the minerals processing industry have grown extensively over the years due to the many benefits derived, both financially and operation-wise. Although control theory is widely known, conventional control does not address many of the problems posed by minerals processing circuits. Some of these problems include interactions between process units, large dead times, few and sometimes unreliable measurements of process variables, non-linear systems, disturbances entering the process, processes with varying dynamics, and many more. For the past 26 years Mintek has been active in the field of providing specific, customized solutions for the minerals processing industry. This paper focuses specifically on applications in milling and flotation control. The underlying control principles have been applied to a wide range of other processes including submerged arc furnaces. Advanced control application is implemented on a common advanced control platform, called the PlantStar. Much innovation has been brought to the fore in terms of adapting theoretical techniques and developing new methods to resolve specific milling and flotation circuit issues by using process control. The general approach adopted by Mintek when implementing advanced control is to enforce stabilization of the process as a solid foundation for optimization strategies to be built upon. In doing this, a robust control solution is presented, and the end result is flow and level stability, better product quality regulation, increase in throughput and a stable feed to downstream processes. The MillStar advanced milling control system ensures that the milling circuit is at all times easy to operate while achieving optimum product quality and throughput. Stabilization should include product size regulation and sump level control. Another important aspect of stabilization control is the handling of milling circuit constraints without introducing cyclical behaviour and with minimal disturbance to the final product quality. Process constraints may include factors such as process water limitations, cyclone feed density, and cyclone underflow angle. An optimization strategy should be developed to increase the mill throughput without affecting product quality or introducing mill overloads. The relationship between solids feed and power draw is examined and manipulated for optimization. The interactive nature of flotation circuits and the presence of recirculating streams tend to make satisfactory control almost impossible with conventional techniques such as PI (Proportional plus Integral) or PID (Proportional, Integral and Derivative) control. The FloatStar Level Stabilizer simultaneously considers all the flotation levels in a circuit by use of a multivariable algorithm, and takes compensating action in anticipation of disturbances. The FloatStar Flow Optimizer is an optimization strategy that controls the concentrate flow rate between various sections of a flotation circuit (e.g. Rougher ?Cleaner; Cleaner ?Recleaner). By controlling the concentrate flow between the sections, the mass pull, circulating loads and residence times of the circuit can be stabilized, thereby enhancing the performance of the flotation process. Optimizing grade and recovery are coupled with the dynamic optimization of circulating flows. The FloatStar Grade-Recovery Optimizer will maximize the grade in a section, whilst ensuring that recovery or any other process specific limits remain within predefined limits. With successful applications on several milling and flotation plants worldwide processing amongst others PGMs, gold, copper and nickel, Mintek has shown that it is a leader in milling and flotation control innovation

Jan 1, 2004

By C. J. Pretorius

More than 30 percent of the global demand for zircon (ZrSi04) is supplied by South Africa. A significant amount of the zircon is exported, and beneficiated products are then imported for industrial applications locally. Beneficiating the zircon locally could have a positive impact on the local market, since zircon is only one of many such cases. Ammonium acid fluoride serves as an alternative anhydrous fluorinating agent for zircon in the synthesis of several metal fluorides1,2. It provides an effective dry fluorinating method and is easier to handle than hydrogen fluoride or fluorine gas. Zircon exposed to extreme plasma temperatures dissociates and becomes more reactive. The reaction of the plasma-dissociated zircon (Zr02.SiO2) with the ammonium acid fluoride (NH4F.XHF, where x= 1 to 5) forms two main intermediate compounds (NH4)3ZrFr(s) and (NH4) 2SiF6(s), the latter decomposing to form volatile products at relatively low temperatures, providing easy separation of the silicon and zirconium compounds. The ammonium zirconate compound decomposes to form zirconium tetrafluoride (ZrF4), which can be further manufactured into zirconium metal, to name but one product. Data on the kinetics of the reaction of ammonium acid fluoride with zircon and plasma-dissociated zircon, combined with the thermo¬dynamic parameters of the reaction, is essential for the development of an industrial process for the production of a precursor for the manufacturing of zirconium metal, namely anhydrous ZrF4. Both the reaction kinetics and reaction parameters will be included in this study, as well as some proof that the reaction proceeds to ZrF4 on a small batch scale. If the exact reaction parameters can be pinned down, a wide spectrum of anhydrous metal fluorides can be synthesized through this fluorination route.

Jan 1, 2012

By C. J. Badenhorst

The scope of this project was to research, develop and eventually produce a personal occupational hygiene and safety exposure monitor system to assist in recording and analysing various stress factors that could affect the health, wellness and safety of employees, i.e. that could result in injury or ill health of workers, create stress build-up within individual workers that could negatively affect worker alertness and safety, and, may even result in permanent disability or death. Utilized systems at the time were all reactive, whereas the DOHEMS (Proactive Digital Occupational Hygiene and Safety Exposure Monitoring) System enabled the measurement of exposure (and associated risk) in a proactive manner via real-time exposure and digitized recordings. The idea of the development was to create a unit that is so cost effective, small and light that every worker can use a system on a daily basis. The development will eventually replace current, bulky and expensive monitoring equipment. The device must be a portable battery operated device and monitor the immediate working environment by periodic sampling for vibration, noise, toxic gasses (NO/NOX/CO/VOC, etc.), body temperature and heart rate. The samples must be time and date stamped, utilizing a real-time clock (RTC) synchronized with the closest regional secondary time source and related to synchronized real-time video captured samples. These samples are then recorded onto a rugged non volatile storage device with the capacity to store a vast number of samples covering the entire working shift of eight (8) hours plus. The system has been fitted with a clear visual local alarm indication system, indicating any excessive exposures or stresses, for the worker?s supervisor to respond to. This system allows for a pro-active approach. The system is also a wireless system (to the external environment) so as to not affect the mobility of an employee and flameproof to allow for use in explosive environments. Keywords: safety, digital, exposure, monitoring, proactive.

Jan 1, 2010

By Bill Almdal

Today?s presentation ? Role of the Regional Issues Working Group ? What does RIWG do? ? How can RIWG?s work benefit Stakeholders? ? Review of forecasts vs. reality ? How have past investment compared to the reality? ? Risks to future growth ? The growth potential is very high and so are the risks ? Examples of outputs ? Housing needs ? Growth in population ? Tires for large trucks The Regional Issues Working Group ? Our vision ? To provide a proactive process which promotes the responsible, sustainable development of resources within the Regional Municipality of Wood Buffalo for the benefit of all stakeholders ? What we do ? Facilitate planning for growth ? Facilitate effective and efficient resolution of issues ? Involve all of the resource developers and affected stakeholders in planning ? Develop plans for sharing benefits with Aboriginal stakeholders ? Benefits for Stakeholders ? Our forecasts include up-to-date information from all developers ? including information on employment and housing needs ? Our forecasts are the basis of planning for many stakeholders ? and can assist in their development planning

May 1, 2002

By William L. Rice

This Bureau of Mines Open File Report on nickel is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign nickel properties and deposits has been abstracted for use in this report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 1984

By Dechun Lou, Benjamin Ravary, Merete Tangstad, Stein Wasbø, Sean Gaal

The melting phenomena of manganese ore, slag and alloys were studied in an experimental sessile drop furnace. Particles of approximately 20-60mg were placed on graphite substrates and then heated at a constant rate of 5°C/min up to 1830°C in a controlled gas atmosphere of Ar or CO. The shape of the particle was photographed with a digital video camera every second. It was observed that the melting behaviour can vary significantly, with some particles exhibiting a large softening/melting range. Selected samples were sectioned and then analysed with EPMA. The implications of the results on understanding industrial furnace operations are discussed.

Jan 1, 2007

Electroosmotic Dewatering and Consolidation of Mineral Waste Tailings

Sep 13, 2010

By Richard Quirk

This report describes methods and techniques employed by The Glidden Co. of Cleveland, Ohio, in explorating an ilmenite-bearing sand deposit in Ocean County, New Jersey, during 1960 to determine ore reserve potential and the feasibility of mining and establishing a milling plant on the property for the production of ilmenite concentrate. The property covered approximately 1,250 acres. Comprehensive sampling by water-jet drilling indicated the deposit averaged 20 feet in thickness and contained 4.5 percent heavy minerals, of which 80 to 85 percent was ilmenite and leucoxene. Average depth of the water table as determined by auger boring was 16.8 feet. Pilot plant tests indicated that circular concentrators in combination with spiral concentrators would recover at least 80 percent of the heavy mineral content of the sands. It was estimated that sufficient ore reserve tonnage had been developed to supply the company's Baltimore chemicals division, pigments department, with a suitable grade ilmenite concentrate for a period of 20 years at the present rate of pigments production. The property was designated as Lakehurst mine and plans are in progress for mining development and plant construction.

Jan 1, 1963

By A. P. Gize, J. F. W. Bowles, D. J. Vaughan, S. J. Norris

Paper presented at the IAGOD international symposium on mineralization related to mafic and ultramafic rocks held in Orleans, France, 1-3 September 1993. Geological evidence from tropical laterites indicates clearly that platinum group metals are taken into solution and precipitated to form grains larger than those in the source rocks. Platinum and palladium move differentially in the surface environment, with Pt partitioning into soils and eluvial or alluvial deposits while Pd remains more mobile in natural waters. Natural organic acids, particularly humic acid, can interact with platinum-group elements and concentrate them even in areas where their content in rocks is very low. Experimental work has confirmed that Pt and Pd can be taken into solution by humic acid at room temperature and in geologically short time-spans. Solubility and deposition may be controlled by physicochemical conditions, reaction kinetics or an adsorption effect, or there may be two competing reactions, solubilisation assisted by organic matter and a kinetically slower metal precipitation

Apr 1, 1994

By W. H. Schiffbauer

NIOSH has developed an active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) for warning workers as they approach known dangerous areas around heavy mining equipment and other dangerous work zones. HASARD is composed of a transmitter and a receiver. The transmitter generates a 60-kHz magnetic field using one or more wire loop antennas. Each antenna is adjusted to establish a magnetic field pattern for each hazardous area. The receiver, worn by the worker, is a magnetic field strength meter. The received signal is compared against preset levels which are calibrated to identify levels of danger. The receiver outputs can include visual, audible, and vibratory indicators and it can also be made to disable machine functions. HASARD was field tested on a Joy 12 continuous miner, a Komatsu 210 M Haulpak, and on a highwall launch vehicle. Slight modifications were made for each application. HASARD provided warnings as designed and proved to be rugged enough to withstand the harshest of production environments.

Jan 1, 2001

By Tapiwanashe Chenje, David Hewitt, Peter Radziszewski

"Steel media wear is a major cost component in mineral processing. In the case of existing operating mill, steel media wear prediction can be used to help compare the performance of steel media from different suppliers before completing marked ball tests. It can also be used to investigate how ores from different site of a given mine affect steel media wear. In the case of Greenfield cases, steel media wear prediction can be used to estimate the cost of steel media for a given feasibility study.This paper presents a wear testing and prediction methodology that ties together abrasion wear and corrosion wear testing results through the use of a simplified discrete element charge motion model. The experimentation dimension to this methodology takes samples for steel media, mine site ore and water to determine abrasive and corrosive wear parameters of a given media, ore, water set.The test methodology development is illustrated along with a comparison of wear predictions with observed wear rates in some operating mills. A case study is included that illustrates how this methodology was used to estimate steel media wear performance. The paper closes with a discussion on the use of parts of the experimental methodology to investigate other abrasive wear conditions such as liner wear, paste backfill piping and ore breakage as well as avenues for future test development.INTRODUCTIONThe cost of comminution processes represents a significant part of the overall costs of a mining operation. Grinding media/liner wear alone accounts for 15-25% of the total operating cost. The annual steel grinding media consumption is approximately 2.5 mtpa or 0.3% of total world steel production [Smorgon Steel Group, 2005]. Using an estimated grinding media cost of about US$0.75/kg [Halbe and Smolik, 2002], gives a media cost of over US$1.875 billion per annum. Mining continues to shift towards exploitation of lower grade ores as the higher grades get depleted. These low-grade ores require finer grinding for the liberation of the value minerals, and hence it can be assumed that grinding media consumption will also continue to rise.The Bond abrasion test, dating back to 1963, [Weiss, 1985] is still used to estimate the total mill media wear. This is a purely empirical test based on the ore. From Bond abrasion index tests, it is possible to determine a wear rate using the following function:"

Jan 1, 2009

Operations of the new copper smelter at Mount Isa commenced on the 6th February, 1953. Prior to this date a paper by R. V. Anderson (1953) outlined the smelter layout, proposed operation and expected performance.Nominally a 50-ton per day plant, output is currently at the rate of 85 long tons per day. In the first 3t years, of operation to 30th June, 1956, '71,339 tons of blister copper were produced. Operation has been stabilized' and a number of modifications to plant and operation have been made. This paper reviews the progress made to date.GENERAL LAYOUT AND EQUIPMENTThe general layout and equipment follows well-established practice as study of Figs. 1 to 4, and Appendix II will show. This diagrammatic representation of layout (Fig. 1) and flow sheet (Fig. 2) is intended for the purpose of brevity to take the place of a detailed plant description.Choice of site for the smelter was limited by the necessity for close proximity of the waste heat boilers to the powerhouse.Much excavation was necessary before foundation work commenced, but the plant is compact and further expansion is possible.CHARGE MAKE-UPRoaster charge initially comprised concentrates, purchased ores, revert materials, mine sulphide ore and barren sand. As purchased ore receipts increased and as domestic black rock oxidized ore became available, the latter two fluxes were eliminated from the charge. Fluxes at minus i-in. sizing are trucked from crushing plant or stockpile by motor lorries. Filtered mill concentrates are dropped from an overhead conveyor on to the storage patio floor adj acent to the two concentrate bins.

Jan 1, 1957

By Armin W. Stuedlein, Youssef Bougataya

Early stage design of driven piles primarily relies on static analysis based on one or a combination of total and effective stress approaches, the latter known as the method to estimate axial capacity. A database of 85 piles driven in the Puget Sound Lowland region and monitored at End of Driving (EOD) and Beginning of Restrike (BOR) was compiled along with capacities estimated using the CAPWAP procedure. Established soil profiles based on borings with standard penetration tests (SPT), cone penetration tests, and geologic maps were matched with their corresponding unit shaft resistance profiles from the CAPWAP procedure and resulted in more than 1,200 observations. In this study, eight new models were developed to predict the coefficients at EOD and BOR, based on the corresponding USCS categorization. Each coefficient model is formulated using a three-parameter exponential function, calibrated to capture the profile of coefficients with depth. These models could benefit the designer by providing them with a simple, empirical model that accounts for soil type and setup in a smooth, continuous function with depth. A parallel analysis was performed to assess the accuracy and variability of the formulated prediction models to facilitate implementation in load and resistance factor design (LRFD). INTRODUCTION The design of the axial capacity of driven piles during the planning stages of a project is typically based on a static analysis approach. The goals of this approach are to predict the components of capacity, consisting of the shaft and toe bearing resistances, and to assess project concept feasibility and preliminary lengths. In most cases, this analysis is based on empirically-developed methods, such as the total stress method, also known as the method (Tomlinson 1987) or the effective stress method known as the method (Esrig and Kirby 1979; Fellenius 1991). Many other methods, such as those based on in-situ test results exist and rely on correlations of blow counts from the standard penetration test (SPT), and cone tip and sleeve friction resistance from the cone penetration test (CPT), to shaft and toe pile resistances (Schmertmann 1978; Meyerhof 1976; Nottingham and Schmertmann 1975; Nordlund 1963; Eslami and Fellenius, 1997; De Ruiter and Beringen 1979). Although these methods were generally developed using data from specific geological regions, they are often recommended in national design manuals (e.g., FHWA, Hannigan et al. 2006).

Jan 1, 2018