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By Satid Therdkiattikul, Donald A. Dahlstrom

By oxidizing the pyrite matrix through biological leaching of precious metals ores or concentrates, better than 90% recovery of gold and silver is achieved. The paper develops three precipitation processes that eliminates arsenic and all other toxic elements in the resulting liquor after the biological reactors. In addition, the precipitates are highly crystalline and resist resolubilization. The latter must be tested for at least six months by EPA test procedures. The three systems are temperature (must be at least 120°C or higher) lime or limestone. A continuous pilot plant was employed for all three systems and complete recommendations are given to optimize Fe/As molar ratio, reaction kinetics (detention time) pH, temperature, wt % feed solids as well as resultant reagent consumption based upon continuous operation.

Jan 1, 1995

By F. A. Penning

This report describes the development of skip and guide desings for vertical shafts in deep vein mines. Skip and guide systems for bottom dump skips are identified as being used in current practice. Mine visits were made to obtain current information on the needs and problems of operating mines. Methods of structural and mechanical analysis of skip bodies and bails are outlined. A dynamic computer model was written to find the dynamic interaction between skips and guides for guides with geometric misalinements. A materials evaluation section identifies currentavailable and applicable materials that can be used effectively for new skip construction. Guide materials are also presented. Analysis includes the economies resulting from streamlined buntons and from low skip payload ratios. Selection of materials is based on strength, abra¬sion and corrosion resistance. Design requirements related to the shaft environment are presented. Consideration for the selection of guides and buntons is also given. Conceptual design includes the concept of cylindrical skips, center-seeking guide rollers, and asymmetric bail design to decrease dynamic interaction. An outline for field tests is presented. Future research areas are: testing, guide geometry measure¬ment, advanced suspension, dynamics, and structural configurations.

Jan 1, 1977

By J. E. Kogel

Industrial minerals play a central and dual role in the sustainable development (SD) of natural resources. Over the past decade the mining industry has increasingly focused on sustainably extracting and processing industrial minerals. This trend has been driven by higher energy costs, diminishing water resources and sensitivity towards environmental stewardship. Industrial minerals have been used throughout human history as low cost, naturally occurring, materials. Today they are critical components of recycled packaging, energy efficient building materials, light weight paper coatings, and other products critical to the responsible utilization of global resources. As industrial minerals become more widely used in ?green? products, mining companies have established best practices for the sustainable management of industrial minerals mining and processing. These management practices include reducing energy consumption, minimizing water usage, increasing waste recovery through recycling and process optimization, and maximizing the amount of ore extracted per acre of disturbed land. With the commitment to SD principles, quantitative methods for objectively measuring SD performance have become increasingly important. Measuring sustainability impact is a valuable tool for effectively applying SD principles and for making choices that balance sustainable development against other business objectives. SUSTAINABLE DEVELOPMENT AND MINING Sustainable development is a term that has become a common part of our lexicon; however, it has multiple meanings and interpretations leading to a sometimes confusing and contradictory array of definitions. The absence of a single, precise definition reflects the fact that SD is a broad concept or paradigm that offers guiding principles as opposed to a specific set of criteria or regulations enforceable by government or other oversight agencies. While a principle based conceptual approach allows businesses to broadly apply SD practices that are tailored to their specific situation, it has also led the public to sometimes view voluntary corporate SD programs with a degree of skepticism (Walker and Howard 2002). This is particularly true in the mining industry. One reason for this skepticism is that the relationship between SD and mining is misunderstood and to many, sustainably developing non-renewable mineral resources is a contradiction (Rajaram et al. 2005). However, this view takes a very narrow interpretation of the tenets of SD. The second is that mining carries a legacy of poor environmental stewardship that does not accurately reflect current corporate environmental practices Many minerals companies have adopted the Brundtland Comission?s definition of SD (United Nations 1987): ?? development that meets the needs of the present without compromising the ability of future generations to meet their own needs?. This definition is very broad and can be interpreted in a number of ways. It provides a general context for sustainable development and is not intended to provide detailed guidelines addressing specific aspects of sustainable development. To fill this gap the following SD principles were drafted by the international minerals community in 2003 (ICMM 2003): 1. Implement and maintain ethical business practices and sound systems of corporate governance. 2. Integrate sustainable development considerations within the corporate decision-making process. 3. Uphold fundamental human rights and respect cultures, customs and values in dealings with employees and others who are affected by our activities. 4. Implement risk management strategies based on valid data and sound science. 5. Seek continual improvement of our health and safety performance. 6. Seek continual improvement of our environmental performance. 7. Contribute to conservation of biodiversity and integrated approaches to land use planning. 8. Facilitate and encourage responsible product design, use, re-use, recycling and disposal of our products. 9. Contribute to the social, economic and institutional development of the communities in which we operate. 10. Implement effective and transparent engagement, communication and independently verified reporting arrangements with our stakeholders. These guidelines insure that SD concepts are applied equally across the industry while setting a clear performance standard and benchmark against which to evaluate success. By adopting these principles and issuing the Milos Statement (http://www.sdimi.org/milos_decl_October%206_2003.pdf), which provides a more detailed vision for integrating SD into everyday business operations, the minerals industry has embraced SD as a core corporate value. The unifying and holistic approach embodied in SD principles impacts the entire mine to market life cycle and addresses the economic, environmental and social consequences of mining. INDUSTRIAL MINERALS The world economy relies heavily on minerals; they are essential to economic prosperity and the quality of life. Industrial minerals are non-metallic, non-fuel minerals that provide the raw materials for a vast range of products used in most every aspect of daily life. They are mined and processed worldwide and they span the spectrum from relatively low value, high volume commodities (e.g. common clay, crushed stone) that are usually mined locally to high value, low volume specialty materials that are sourced from unique one of a kind deposits (e.g. barite, talc, mica). High volume commodity mining operations are often located near the end use market which, in most cases, means areas of high population density where construction and other urban activities drive demand. In these situations the strict adherence to SD principles is particularly critical as these are highly visible operations that must meet the public?s demand for good corporate citizenship. These operations are similar to chemical or other manufacturing facilities that operate near population centers. In contrast, some mining operations are located in remote but environmentally sensitive regions of the globe where the pressure to mine sustainably is driven by the need to preserve habitats and other

Jan 1, 2009

By Harvey Patashnick

Current state-of-the-art microweighing technology represented by the Tapered Element Oscillating Microbalance (TEOM) is utilized as the basis for a new generation of Personal Dust Exposure Monitors (PDEM's). Two design configurations are presented. The first is an end-of-shift analysis system which uses small TEOM-PDEM cannisters that replace the filter cartridges in the current PDEM system. All other components carried by the miner (cyclone preseparator and pump) are the same. After the shift the TEOM cannister is plugged into an interface box which enables a minicomputer to automatically identify the unit, determine the dust mass increase during the shift, compute the shift average dust mass concentration, and print out and/or store the data. The second design is a real-time TEOM-PDEM system which is capable of operation over a 10-hour shift and on demand display real-time dust concentration level, time weighted average, and shift average concentration. As a result of the design study, a prototype end-of-shift analysis system was fabricated and delivered to the Bureau of Mines. A description of this system which consists of six TEOM cannisters, interface electronics and minicomputer is given. The system represents a significant advance in the dust monitoring program in terms or accuracy and automation.

Jan 1, 1983

By M. A. W. Bryson

It is well documented that a significant amount of the new PGM (Platinum Group Minerals) production that is coming on stream now, and over the next few years, is to come from the UG-2 reef. Clearly the reservations, or perhaps the perceived reservations, attached to the processing of this ore are no longer there. What were the metallurgical issues that delayed the exploitation of the PGM values from this reef? Traditional furnaces treating Merensky concentrates were not able to accept the concentrate produced from a UG-2 plant due to the relatively high chromite content of this product. The chromite reports to an insoluble spinel phase that accretes in the furnace, resulting in the necessity to shutdown and dig the furnace out periodically. This was clearly not an attractive economic option, so producers stayed away from it in the early days. The Merensky ore had all higher base metal credits anyway, and you needed them to get a matte fall, so there was no driving force to look seriously at the UG-2 reef. Platinum demand at this time could be easily met from the Merensky ore, so the motivation to tackle more complex ores was not there. The low price of PGMs meant that these operations were not particularly profitable and there was little effort directed at improving the operations. Concentrators were generally not run very efficiently and the emphasis was on cost reduction through increasing milling rates.

Jan 1, 2004

By O. K. Mahabadi

The scope of this study is to simulate the behaviour of a layered rock sample under standard laboratory Brazilian Disc test using an innovative combined finite-discrete element method (FEM/DEM) research code. The influence of layering and the direction of loading on the samples behaviour are studied through various layering and loading configurations. A parametric study including the effect of loading rate on the tensile strength of samples has been carried out. This paper demonstrates the suitability of the numerical approach to explicitly model rock deformation and failure.

May 1, 2009

By Austin E. Dwight

IT has been shown by Oelsen and Wever' that the effect of a solute element on the allotropic transformation in iron is dependent upon the quantity

Jan 1, 1957

By S Colak, M Tunc, C Celik, M. M. Kocakerim

The most important parameters affecting the solubility of ulexite (sodium calcium borate) in H2SO4 were found to be reaction temperature and solid:liquid ratio, in that order. Dissolution increased with increase in temperature and stirring speed and with decrease in solid:liquid ratio, particle size and acid concentration, the last effect as a result of decreased precipitation of CaSO4 on unreacted particles. Optimum conditions, in which around 99.5% of the ulexite could be dissolved, were a reaction temperature of 60 degrees C, a solid:liquid ratio of 1:8 g/ml, an acid concentration of 8 mol/l, particle size smaller than 425 micrometres, a stirring speed of 52.33/s, a reaction time of 1 800 s, a calcining time of 3 600 s and a calcining temperature of 170 degrees C. These conditions, determined by the Taguchi method, are reproducible in a commercial production environment

Jun 21, 1905

By Refik Elibay, Lawrence A. Williamson, George D. Barnes

Under an extremely aggressive schedule, final design of 13.5 km (8.4 miles) miles of 8.2 m (27 ft) diameter deep rock tunnel, 322 ML/day (85 million gallons / day)submersible pumping station and associated facilities were accomplished ahead of a federal court mandated consent decree schedule. Challenges overcome by the project team in enabling timely completion of the construction documents will be presented. Discussion includes evolution of final design, consideration of future O&M requirements, and risks identified for construction and operations, together with measures to manage and proactively prepare for such risks.

Jan 1, 2005

In July 1982 the Committee on Underground Coal Mine Safety completed its study of safety in U.S. underground coal mines; the results of the study were published in the National Research Council report entitled Toward Safer Underground Coal Mines. One of the findings of this study was: THERE IS A STRONG CORRELATION BETWEEN MINE SIZE AND FATAL INJURIES. THE FATALITY RATE IN MINES WITH 50 OR FEWER EMPLOYEES IS NEARLY THREE TIMES THAT OF LARGE MINES (WITH OVER 250 EMPLOYEES), AND ABOUT TWICE THAT OF INTERMEDIATE-SIZED MINES (WITH 51-250 EMPLOYEES). Although the Committee explored possible reasons for the higher fatality rate in the smaller mines, it was not able to explain this phenomenon fully. Therefore the Bureau of mines requested that the Committee undertake a supplementary study of fatalities in small underground coal mines. The Committee met in the fall of 1982, discussed the problem, developed an approach to it, approved a program of statistical analyses, and authorized a panel of four committee members to explore the problem in greater depth. The panel, in turn, reviewed the results of the statistical analyses and met with the president of the National Independent Coal Operators Association and with several owners of small underground coal mines for a detailed discussion of the unique problems of small mines. Panel members examined 66 individual fatality reports prepared by Mine Safety and Health Administration (MSHA) inspectors who investigated fatal accidents that occurred in small underground coal mines in 1979 and 1980. This report is the result of those studies, analyses, and deliberations. The first draft was prepared by the panel, but the report has been reviewed and approved by the entire Committee.

Jan 1, 2011

By Frank Sames

Ground vibration levels are generally predicted using equations such as the USBM equation implementing the scaled distance concept and describing geological and blast design parameters in a ground transmission constant.

Jan 1, 1995

By K. [Muthukkumaran

An extensive program of laboratory model tests was undertaken to study the effect of slope on p-y curves under passive loading in dry sand. The paper concerns the method developed in a series of laboratory model tests to experimentally determine p-y curves. Bending moment curves are differentiated by using curve fitting method of cubic polynomial function. The study includes effect of slope angle and relative density on bending moment and non-dimensional p-y curves. The non-dimensional p-y curves for piles on sloping ground under passive load are developed modifying API method by including a Reduction Factor (R) using the experimental results.

Jan 1, 2006

The following report summarizes the results of engineering feasibility studies whose purpose was to assess the probable efficiency, reliability, safety and cost of a number of possible methods for removal of radon gas from the ambient air in underground mines. Fourteen candidate techniques were evaluated. Seven of these were based on specific individual principles, and seven were based on combinations of these principles. The individual principles were as follows: 1. Activated charcoal 2. Organic fluids 3. Semipermeable membranes 4. Molecular sieves 4. Cryogenics 6. Chemical reaction 7. Centrifuge The combinations were: 8. Cryogenics and activated charcoal 9. Cryogenics and molecular sieves 10. Cryogenics and chemical reactions 11. Membrane filters and organic fluids 12. Membrane filters, cryogenics and activated charcoal 13. Membrane filters and chemical reactions 14. Silica and an Organic Fluid

Jan 1, 1975

The Acid Leaching Process for the Synthesis of Zeolitic Material from Paper Sludge Ash

Sep 13, 2010

By H. Mitri

A new monitoring device called SAFEBOLT (Stress And Force Evaluator in BOLTs) has been recently developed at McGill University. The device is essentially an alternative to the load cell, it permits the monitoring of bolt axial load in the field. The SAFEBOLT system consists of a portable readout unit, a connecting cable and the SAFEBOLT device, which is installed in the bolt head. The new device can be installed on any industry standard rockbolt or rebar. The device is completely encapsulated in the bolt head, which makes it resistant to corrosion, rugged, and free of any electric wires. Pilot tests at two underground Quebec mines were carried out and helped improve the initial design of the device head.

Jan 1, 2002

By J. Eriksson

Slag from stainless steelmaking is known to disintegrate, which is an environmental problem and prevents the cooled slag from being utilized. This disintegration is due to the transformation from the ßto the ? polymorph of di-calcium silicate. The transformation is accompanied by an increase in volume of about 11% and a total disintegration of the slag. AOD slag from stainless steelmaking was re-melted in a laboratory induction furnace, together with olivine and calcinated dolomite, to investigate the prevention of disintegration by increased MgO content of the slag with small changes in CaO to SiO2ratio. The modified slag was examined with X-ray diffraction and scanning electron microscopy. The trials showed that an increased MgO content can change the mineral composition towards formation of more Merwinite and Bredigite, which prevents disintegration of the slag. Keywords: slag, disintegration, di-calcium silicate

Jan 1, 2004

By Loring A. Wyllie

Preparation, understanding and use of soils reports must be a team effort to be fully effective. The soils engineer must know what is to be built and exactly where. The structural engineer and owner must be fully informed on the foundation problems of the site. There must be frequent team review of information obtained from subsurface investigation and of design as details develop. The soils engineer should be available on a continuing team basis as design proceeds and should be directly involved with inspection and interpretation of site conditions as construction continues.

Jan 1, 1986

By C Jia, J Graindorge, L M. Olssen

Picking up abandoned mining tenements and looking to recover remnant resources around old operations is an opportunity that comes with its own challenges and risks. Reliance on information released to government departments (such as the Department of Mines and Petroleum (DMP) in Western Australia) by the previous owners, can compound the risk.This paper explores Alto Metals Ltd’s Lord Nelson and Lord Henry deposits and surrounds near the town of Sandstone in Western Australia. The Lord Nelson and Lord Henry open pits produced around 2 Mt of ore for over 250 koz of gold during production between 1999 and 2010. There has been no further work carried out in the area between 2010 and 2016. The deposits are open at depth and along strike.Alto Metals picked up the tenements in 2016 and has subsequently re-estimated remnant resources around Lord Nelson and Lord Henry, and publicly reported updated Mineral Resources in accordance with the JORC Code 2012.All of the information was manually compiled from data released to the DMP and annual reports. This paper highlights the challenges and risks arising from this data compilation, geological interpretation, re-estimation and classification process, together with future opportunities and challenges for further developing the area.CITATION:Olssen, L M, Graindorge, J and Jia, C, 2017. Starting from scratch – defining remnant resources from publicly available data: a case study from the Lord Nelson and Lord Henry gold deposits, in Proceedings Tenth International Mining Geology Conference 2017, pp 175–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

How Particles Stick to Bubbles - The Influence of pH and Hydrophobicity in Flotation

Sep 13, 2010

The recovery of coarse particles has been widely recognized as being limited by the froth in mineral flotation. In response to this, FLSmidth has developed the Selective Froth Recovery (SFR) System. The SFR System is an extraction system that vacuums material from select locations within the froth and separates the recovered solids into coarse and fine fractions with a hydrocyclone. The SFR is supported and located by an actuator connected to the cell?s level control so that the suction heads are maintained at an offset distance from the slurry level. This can increase the recovery of coarse material by selectively recovering the material close to the bottom of the froth where drop-back of coarse particles typically takes place. The SFR System has been tested at two separate mine sites, and has been proven to increase the copper recovery in both trials. TEST RESULTS The SFR prototype was installed in a copper recovery circuit, on a rougher scavenger 160-m3 flotation cell. Figure 1, shows the SFR System, which consists of four conical skimmer heads that are plumbed together and share a common actuator. The SFR System, raised out of the froth prior to a test, can be seen in Figure 2. The SFR prototype was able to maintain a variety of set points using the level control to determine the slurry height.

Feb 27, 2013