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By Antonio Nieto, Jesus Castillo

Research and Development (R&D) departments in the mining sector are essential for creating new solutions on productivity, safety, and sustainability. Nevertheless, the selection of R&D projects is complex, often influenced by subjective judgments and uncertainties. This paper explores the application of the Multicriteria Decision Analysis (MCDA) as a structured approach to evaluate and prioritize innovation projects based on various criteria such as safety, cost, environmental impact, and social acceptability. By assigning weights and quantifying criteria, MCDA enhances decision-making transparency and objectivity. This study aims to show a method that facilitates strategic thinking, resource optimization, and stakeholder engagement, ensuring that selected innovations align with the company’s long-term objectives and commitment to responsible mining practices.

Feb 1, 2025

By H. L. Bourne

This paper describes six basic stages between perception and production for a new sand and gravel deposit. Sand and gravel, like many of our natural resources, is taken for granted. It is assumed by John Q. Public that because sand and gravel is ubiquitous that it is available whenever and wherever needed - so long as it does not have to be mined in his neighborhood. This idea illustrates one of the enigmas of the industry, the fact that sand and gravel is abundant; however, its availability is another matter. Another problem is that this resource falls in the category of high volume, low profit materials; therefore, transportation costs are critical. Transportation roughly doubles the cost of these materials. It is not difficult to find sand and gravel, at least in Michigan. The problem is to locate a new source close to a market, near an adequate transport route (usually a highway) and in an area which will allow mining.

Jan 1, 1970

By Joseph J. Zaluski, J. Steven Gardner, Marco M. Rajkovich

The telephone rings at 3:20 a.m. An exasperated voice on the other end says, “There has been a mine explosion at Mine No. 5 and we have not heard from three units of men.” Twenty-three minutes later, the phone rings again and another panicked voice says, “There is something wrong at the slurry impoundment, the pool level has just dropped five feet and we are trying to figure out what is wrong” Thirty minutes later, the mobile phone rings. An excited security guard says, “We have reports of thick black water running down the right fork and left fork of Straight Creek and both seem to be rising in the banks.” If this is not enough excitement, the mobile phone rings again. A stressed company official says, “I just heard a report that black slurry is running out of the portals of XYZ Co. No. 2 Mine, which is adjacent to our No. 5 Mine.” Is this all some kind of dream or nightmare? More importantly, though, if this happens, what do you do? Most people think: “It can’t happen to me.” But mine explosions do happen, slurry impoundments can rupture and creeks can flood with black water causing damage to others, including competitors. A mine’s response must be quick, cool-headed, calculated and effective. This article examines the issues, concerns and ramifications of this hypothetical disaster. The authors then present a systematic crisis-management response.

Jan 1, 2004

By A. B. Cecala

Over the past decade, a substantial effort has been made to improve the air quality inside enclosed cabs of both underground and surface mobile mining equipment to reduce respirable dust exposures to the equipment operators. As part of this effort, the National Institute for Occupational Safety and Health, (NIOSH) completed a comprehensive laboratory study which determined the significant factors for cab filtration and pressurization systems. From this information, a major underground mining equipment manufacturer designed a filtration and pressurization system which was incorporated into the enclosed cabs of its equipment. A long-term evaluation was performed on the effectiveness of this filtration and pressurization system to improve the air quality in the enclosed cabs of two different pieces of equipment, being a face drill and a roof-bolter machine, at an underground limestone mine. This long-term evaluation demonstrated a significant reduction in dust levels comparing outside to inside cab respirable dust concentrations. During this evaluation, a modification to remove one of the filters on the roof-bolter machine simplified the design without sacrificing the system?s efficiency. Testing using particle count instruments performed during non-production time periods on both pieces of equipment indicated Protection Factors greater than 100 when comparing respirable-sized dust particles inside the enclosed cab relative to outside.

Jan 1, 2012

By P. Burmeister, R. A. Errath, A. Sapin

Sag Mills are becoming bigger in size almost every year. Concentrator plants are also becoming larger with more SAG and Ball Mills units with Gearless Mill drives installed in one plant. In contradiction to this development, concentrator plants are being built in increasingly remote areas, where the power supply and network conditions are not necessarily covering the needs for the operation of such plants. This paper describes sources of harmonic distortions and possible approaches to solve this problem. It also illustrates the permissible tolerances in terms of commutation of power electronics, based on already realized installations. Furthermore it explains how, and with which measures, harmonic currents created by non-linear loads with SAG and Ball Mill drives can be handled, and how harmonic standards can be fulfilled accordingly. Finally, this paper gives an overview about the technical impact of a strong versus weak network, and the economic relationship between them.

Jan 1, 2001

By P. L. Crouse, S. J. Lubbe, M. J. Kabangu

A selective extraction and separation of zirconium by solvent extraction with 1-octanol is proposed. The process is based on the dissolution of the metal basic carbonates in hydrochloric acid in the presence of potassium fluoride, using 1-octanol as extractant. The effect of several process parameters, including hydrochloric acid and potassium fluoride concentrations, reaction time, and phase ratio between the aqueous and the organic phase was investigated. Zirconium is enriched in the organic phase. The best extraction and separation results were obtained with the basic carbonate dissolved in 10% hydrochloric acid and 1.5 M potassium fluoride. The optimum reaction time was 15 min with an organic to aqueous phase ratio of 2:1. Based on the selectivity of zirconium over hafnium in the organic phase, a McCabe-Thiele diagram was constructed. A near complete stripping of zirconium from the organic phase was achieved using a 3 M sulphuric acid solution. Additional studies are required in order to determine the reaction mechanism and the chemical speciation of the current investigation.

By Mark C. Holton

The mining industry has recently been. - experiencing a difficult period. Escalating costs, lower grades and deeper level mining, are a few of .the reasons' why interactive graphics or CADD (computer aided design and draughting) systems are increasingly being used. CADD systems which support powerful and flexible mining applications have great potential for making all forms of mining more efficient and effective. There are many application programs which address almost every aspect of mining. Most of these programs originated to satisfy a particular need. Graphics and other features were added until they, reached a point where they were commercially viable as a mining package. Because of their evolution these packages, lack many CADD-type features. Today there are powerful personal computers (PC's) and engineering workstations running the best CADD systems available. These systems, support hundreds of applications in almost every discipline. Mining was until recently not well supported by interactive graphics vendors because of the highly variable nature of mining and the lack of common standards. Users of CADD systems have experienced the benefits of CADD and come to expect similar features from graphic mining packages. Several developers of mining packagers have either attempted to include some CADD features or make their packages compatible with one or other CADD system. Mining can benefit greatly From a combination of interactive graphics (or CADD) and the right mining application software.

Jan 1, 1989

This paper presents a virtual prototype for the stress analysis of cable shovel components based on combination of flexible and rigid body approach. The general mechanical system of the cable shovel is modeled as a multi-body system with rigid and flexible bodies. The relevant theories applied for the dynamic model are described in terms of Lagrangian multi-body dynamics and finite element method. A virtual prototype of the cable shovel is built in the Automatic Dynamic Analysis Mechanical System (ADAMS) environment, which allows visualizing the motion of general mechanical system and analyzing the dynamic stress of structural components of the cable shovel. An example is given to perform dynamic stress of durability analysis for the boom and handle. Attention of this study is devoted to the mechanisms of damage of the cable shovel and also the critical high stress areas. Keywords: Cable shovel, Von Mises stress, Virtual prototype simulation, Stress virtualization.

Jan 1, 2009

By P. Harris, G. Groenmeyer, L. Parolis

The effect of molecular weight, charge and the presence of the cations Ca2+, Mg2+and K+ on the adsorption of carboxymethyl cellulose on pure talc obtained from Balmat, New York have been investigated. Higher adsorption densities were obtained in the presence ofCa2+ and Mg2+ ions than with K+ ions and higher ionic strength solutions resulted in higher adsorption densities. Changing the molecular weight did not influence the adsorption however increasing the charge (DS) of the polymers resulted in lower adsorption densities.

Jan 1, 2004

By Kristian E. Waters, Hao Ma, Haibei Wang

Over the past few decades, ELM based separation processes have become an attractive and efficient way to remove toxic metal ions from the various aqueous waste effluent streams. This paper provides a comprehensive review of the generation, characterization, and applications of emulsion liquid membrane (ELM) from the more than 280 papers and books published so far. First, the ELM formation and the transport mechanism are introduced. Then the ELM stability and emulsion splitting methods are discussed in detail, followed by the latest research and findings of the extraction of copper and nickel using the ELM technique during the past few decades, including a thorough discussion of ELM operating parameters that impact ELM stability and extraction. In addition, the kinetics study and industrial application of this technique for the removal of coppers/nickel solutes are also presented and discussed.

Jan 6, 2023

By William Gleason

The mining industry is a unique space. It is one in which geologists and chemists can intersect with computer and data science professionals daily. The industry requires expertise in not just mining and metallurgical engineering, but also electrical, mechanical, environmental and more. It requires expertise in worker health and safety, behavioral science, finance and economics, as well as human resources management. The locations of mining operations are often in remote corners, and for underground activities, they are unlike anything else in the world. The industry presents those who join it a wealth of opportunities, but often struggles to overcome incorrect perceptions of safety, labor and environmental standards, making it difficult to recruit and retain employees at a time of increased demand for mined materials.

Dec 1, 2025

By Leons Kovisars

Introduction Labor is the major cost element for most mining operations. Labor costs are continually increasing, both in nominal and constant terms. This is true in developed as well as less developed countries. There are two ways to control unit labor costs - labor costs per ton of ore mined. Replace labor with capital (increased mechanization) or improve productivity (reduce the labor force). Every miner is aware of specific inefficiencies at his or her particular operation. But the miner has no comparative measurement standards. So it is difficult to know whether these inefficiencies are major or minor. The miner may also be unaware of large-scale inefficiencies because ongoing labor practices may have caused management complacency. Met Research studied mining labor productivity. The firm collected pilot data by sending direct-mail questionnaires to 320 nonferrous mining operations around the world. The response rate was 27%, of which 78 operations provided full data on production and employment.

Jan 11, 1983

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2007 draws upon available information from industry, literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analysis of the mineral industry based upon these data. Two types of information are reported and analyzed in this annual review of international exploration for the year 2007: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia, and 2) information on regional and site-specific exploration activities that took place in 2007 and compiled by the USGS.

Jan 1, 2008

By Mark E. Smith

Oxide ores can consume enormous amounts of expensive sulfuric acid. The problem is amplified with increasing heap heights. One solution is to provide a thin liner and drainage system between each lift of ore, thereby intercepting the pregnant leach leach solution (PLS) after it exits the active lift. However, these liner systems require special attention to hydraulics, slope stability and geomembrane design criteria. Inadequate attention to the first two can result in reduced recoveries, increased acid consumption andsystem failures. The geomembrane selection criteria are different from the base liner, and optimizing its selection can have significant effects on the operation’s bottom line.

Jan 1, 1996

By Ginger L. Hustrulid

Conveyor belts are a critical component in tunneling projects. This paper reviews current design considerations for conveyor belts. Rubber compounding differences to meet local fire resistance regulations or certain cover characteristics such as higher abrasion resistance or low carbon footprint rubbers for applications are reviewed. Evaluation of fabric belts, steel cable belts and the benefits of each carcass design for a particular use is also examined to help with proper carcass selection to decrease downtime from unexpected failures. Finally, this paper takes a look at some of the differences when working in metric versus imperial units.

Dec 1, 2022

By Stig Premfors

Lamco Joint Venture is operating a Dravo Pelletizing machine to produce pellets from the natural slimes of an earthy hematite ore. The grate area of the machine 3.3 x 106 m equal to 350 m2 (3800 sq. ft.) and the installed fan capacity is 8200 HP. The limiting factor for production is normally fan capacity. This means that the processing fans can not pull the additional air (i.e the additional calories or BTUs) through the bed which would be required for increased production. A way to increase production without major modifications is to supply the additional calories needed for increase production by adding coal to the pellet feed. After successful laboratory tests following method of coal addition has been chosen and the following results have been obtained. 1. The ground coal is added to the slurry prior to the filters and the rotary dryer. 2. By adding 0.6% coal, an increase of about 15% in production rate has been obtained. 3. No significant changes of metallurgical properties have been observed (i.e. tumbler index, compressive strength, ferrous iron content, reducibility, Linder degradation and swelling). 4. No unexpected operation problems have been experienced. The pellet discharge temperature increases and is the limit for how much production can be increased by coal addition without making plant modifications.

Jan 1, 1971

By Qingming Feng, Jinhong Zhang

A study has been carried out to apply fly ash as a high strength, water-resistant precast construction material through geopolymerization. Experiment results show that the working conditions such as water content, the concentration of NaOH, curing temperature, and curing time significantly affect the mechanical property of geopolymermatrix. Through optimization, an above-100MPa compressive strength has been achieved with the geopolymerization products. The optimum working conditions involves 10MNaOH concentration, 14–15% water content, and curing at 90 °C in an oven for 1 day or at ambient condition for 3 weeks. Adding Ca(OH)2 does not help to increase the compressive strength of the specimen.Water soaking tests show that the geopolymerization product has a very high water resistance without losing noticeable compressive strength, even after a 1-month soaking time. To elucidate the geopolymerization mechanism, microscopic techniques such as SEM/EDS (scanning electron microscopy and energy-dispersive X-ray spectroscopy), XRD (X-ray diffraction) and ATR-FTIR (attenuated total reflectance Fourier transform infrared) are also applied to investigate the microstructure, the elemental and phase composition of geopolymerization products. The findings of the present work provide a novel method for applying fly ash as a high-strength water-resistant precast construction material.

Aug 17, 2020

By Felicia F. Peng

Using granular media for removal of soluble manganese from mine water and industry waste stream has the advantage of forming a compact surface layer of manganese oxide coating on the media. This process can avoid the step involving the separation of voluminous sludge of manganese hydroxide by the high-pH method for soluble manganese removal. The removal of soluble manganese is accomplished by adsorption and oxidation. The adsorption of Mn(II) on the manganese oxide-coated media was rapid through the specific adsorption and may be due to the ion exchange of hydroxyl ions on the manganese oxide by Mn(II). In the subsequent step, the adsorbed Mn(II) form the intermediate manganese complex on the manganese oxide product is oxidized with dissolved oxygen or other available oxidant source in the aqueous solution. This paper presents the efficiency of removal of soluble manganese from mine water by using a laboratory fluidized bed and the recovery of manganese oxide coating on the anthracite coal particles. In order to accelerate the formation of the manganese oxide layer on the surface of anthracite media, dilute potassium permanganate solution is used as an active oxidant. The effects of operation parameters on the manganese removal including pH, flow rate, concentration of feed and oxidant dosage are evaluated.

Jan 1, 1996

By J. O. Marsden, M. M. Botz

"Heap leaching is responsible for approximately 21 percent — 3.9 million metric tonnes — of copper production and 9 percent — 270 metric tonnes or 8.7 million ounces — of gold production worldwide. Given metal price assumptions of $2.25/lb for copper and $1,250/oz for gold, these portions of global production generate revenues of $19 billion and $11 billion, respectively. For heap leaching operations, small changes in metal extraction efficiency drive substantial changes in operating cash flow margins and affect project viability. Variances in actual metal production from budgetary forecast estimates can mean the difference between success (value creation) and failure (value destruction) for a heap leach project. Despite the importance of heap leaching for copper, gold and silver production worldwide, there are no clear standards or guidelines for developing heap leach metal production forecasts. There is considerable variation among copper and gold producers that apply heap leaching technology as to how such modeling and forecasting is applied at the operational level. There are a variety of different modeling approaches that can be utilized for this purpose. However, these vary in cost, complexity, time to implement, accuracy and credibility. This paper explores the options available for heap leach modeling, discusses the advantages and disadvantages of each approach, and provides guidelines/recommendations for an effective approach to modeling metal production at existing or planned heap leach operations. The paper also provides expected ranges of variation between actual and modeled production.Introduction and backgroundHeap leaching is fundamentally different from other methods used in the processing and extraction of gold, silver, and copper and other base metals. Considered globally, the technique represents a relatively modest portion of production compared with the primary technologies applied for copper and gold recovery. Approximately 21 percent of copper production is attributable to heap leaching techniques, as opposed to 79 percent by conventional crushing, milling, flotation, smelting and refining. For gold, about 9 percent of global production is obtained from heap leaching, compared with over 90 percent by various combinations of crushing, milling, gravity concentration, flotation and/or agitated cyanide leaching processes or, in the case of placer deposits, by direct gravity concentration and/or amalgamation. In cases where heap leaching is the primary source of metal production, the ability to accurately forecast metal production may be the difference between commercial success and failure for a project or operation. Heap leaching — of crushed or run-of-mine ore — is also commonly applied as a secondary process to treat lower-grade ores from a given deposit, such as at Chuquicamata in Chile, Cerro Verde in Peru and Bagdad in Arizona for copper extraction and at Twin Creeks and Carlin, both in Nevada, for gold. In such cases, heap leaching provides incremental revenue to supplement the primary process. Variances between actual and forecast metal production from heap leaching as a secondary process are typically tolerated and absorbed within the overall site metallurgical balance. In either case, accurate production modeling and forecasting creates significant value for heap leaching projects, is essential for managing production expectations — timing and volumes — and is likely to be a critical success factor for most heap leach projects."

Jan 1, 2017

By D. Shin

The gold leaching using cyanide from ore or waste has been almost universally in use [1]. Recently, biological gold bioleaching using cyanide producing bacteria, e.g. Chromobacterium violaceum, Pseudomonas fluorescens, or P. aeruginosa, has been investigated as environmental friendly and cost effective method. Among them, C. violaceum has been reported as effective cyanide producing bacterium on gold leaching [2, 3]. C. violaceum produces cyanide using glycine as a direct precursor and subsequently detoxify the cyanide by ß-cyanoalanine synthase [4]. However, until today only 0.026 ? 16.9 mg/L of cyanide production in YP medium has been reported in the literatures by C. violaceum [4-6]. Comparing with adding cyanide chemical, biogenic cyanide concentration is lower than the cyanide concentration added in traditional cyanidation. Since cyanide also forms complexes with a number of other elements such as iron, nickel, zinc, silver, copper, and platinum, it is very important for gold recovery to investigate the enhancement of biological cyanide production and set optimal experimental condition. Most of early studies on gold bioleaching by C. violaceum have been performed to investigate gold leaching mechanism using gold powder, and recently various resources such as ores, electronic scrap, and printed circuit boards of waste electronics [7]. Few studies have dealt with gold bioleaching from low-grade ore. In this research the feasibility of gold bioleaching by C. violaceum from low-grade ores containing gold was evaluated and fundamental study was performed for further scale-up study. The aim of this study was to improve the potential of gold bioleaching by C. violaceum from gold-containing ore; in particular, enhancement of biological cyanide production.

Jan 1, 2012