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By Botelho Junior, Amilton Barbosa, Denise C. R. Espinosa, David B. Dreisinger

Copper and cobalt can be found on nickel laterite ores, and cobalt can be found also on copper ores, and many contaminants such as iron, aluminum, and magnesium are associated with these ores. In hydrometallurgical process, a purification step is necessary after leaching due to the presence of these impurities. Chelating resins are more selective for some metals than others, making them more efficient than cationic resins. This overview discusses chelating resin applications to recover copper, nickel, and cobalt from mining process and mining tailings and the effect of contaminants in leach solution. Chelating resins with iminodiacetate functional group can be used for selective copper recovery, and both iminodiacetate and bis-picolylamine resins are highly selective for nickel and cobalt. Chelating resins with the same functional group can have different performances on the kinetics of loading, because of variations of structure, the density of functional group, and degree of cross-linking. This article reviews commercial chelating resins that can be applied in leach solutions with different compositions, and also possible innovations for uses of chelating resins to recover metals from mining process and mining tailings.

By Brooke T. Mossman

Asbestos fibers are highly fibrous silicate fibers that are distinguished by having a large aspect (length to diameter) ratio and are crystallized in an asbestiform habit that causes them to separate into very thin fibers or fibrils. These fibers are distinct from nonasbestiform cleavage fragments and may appear as thick, short fibers which break along cleavage planes without the high strength and flexibility of asbestiform fibers. Since cleavage fragments of respirable dimensions have generally proven nonpathogenic in animal studies, little data exists on assessing well-characterized preparations of cleavage fragments in in vitro models. The available studies show that cleavage fragments are less bioreactive and cytotoxic than asbestiform fibers. © 2007 Elsevier Inc. All rights reserved. Keywords: Asbestiform; Cleavage; Fibers; Fibrous

Jan 1, 2007

By John F. Gamble

Paper 1?South African experience with asbestos-related environmental mesothelioma: Is fiber type important? Neil White, Gill Nelson, Jill Murray The purpose of this review was to illustrate the importance of the type of asbestos in environmental mesothelioma. South Africa is a logical place to assess fiber type. The three major types of asbestos (crocidolite, amosite and chrysotile) were mined (all asbestos mining stopped in 2002) in South Africa. The association between asbestos and mesothelioma was discovered in South Africa. The occupational literature indicates high mesotheliomagenic potential for crocidolite, less for amosite and less still for chrysotile. Since South Africa has been a major source of crocidolite, relatively high rates of mesothelioma in the mining population is not surprising. High rates of mesothelioma due to environmental exposure is surprising, except perhaps when the authors? point out potential sources for community exposures (e.g., mine tailings used for road surfacing, golf courses, brick and plaster making; insulation in residential ceilings; children playing on fiber-rich waste rock). The authors? reviewed four studies reporting on mesothelioma cases and their sources of exposure and fiber type. Overall 23% of the known cases were attributed to the environmental (not occupational) exposure and about 90% were due to crocidolite asbestos. The proportion of environmental mesothelioma is considerably higher than in Western Australia where crocidolite is also mined. There the overall rate of environmental mesothelioma is about 6% (and less than 1% from residence in a crocidolite mining area).

Jan 1, 2007

By Eugie Kabwe

Rock bolts are components of tunnel support structures and their efficacy in reinforcement requires the appropriate estimation of the bolt pre-tension. However, cases of ineffective rock bolt application due to loosening are common which leads to the potential failure of the support structures, thus negatively affecting the tunnel stability. The effective employment of pre-tensioned bolt within support structures requires an appropriate installation tension as a result of sufficient bolt head/nut pre-load. Henceforth, this paper presents a load indicator washer (LIW) capable of withstanding assigned static loading as well as provides an appropriate pre-tension. The different LIW breadths are numerically analysed in the finite element code (ABAQUS) to estimate deformation when a designated 60-kN pre-load is applied. The numerical simulation employs a bi-linear isotropic hardening constitutive law governed by the von Mises yield criterion. The simulation also considers the nominal temperature of the nutLIW-rock bolt connection. Therefore, a long-term relaxation effect on bolt pre-tension as a result of stress relaxation is neglected. The compressive force required to achieve the LIW-predetermined deformation is the bolt pre-tension. It is drawn from the simulation results that the 1.5-, 2.0-, 3.0-, 3.5-, and 4.0-mm-thick LIWs are completely flattened when subjected to 28-, 42.5-, 65-, 76-, and 88-kN pre-load respectively.

The Canadian mining industry is one of the strongest in the world. Not only does the country produce a sizable amount of minerals and metals, Canada plays host to hundreds of global mining companies, large and small. The country, for the most part, recognizes the importance of natural resource development, particularly mining, to its economic well being. Like any country, though, there are federal and provincial regulations on the books that the industry takes issue with. But there are also certain economic incentive programs in place to encourage exploration and mine investment. And, unlike the industry and the United States government, the Canadian government and mining industry appear to have a reasonable working relationship.

Jan 4, 2010

1. Paper1?Identification and enumeration of asbestos fibers in the mining environment: mission and modification to the federal asbestos standard Arthur M. Langer Asbestos-related disease is increased with cumulative exposure (the concentration of asbestos in the air and duration of exposure). The maximum duration is assumed to be a working lifetime so federal agencies control cumulative exposure by limiting the airborne concentration of asbestos fibers equal to or greater than 5 lm in length. Air samples are collected in the environment of interest by entraining the airborne particulates including fibers on membrane filters and then counting the number of fibers using phase-contrast light microscopy. In addition to length, the fibers must have a length to width ratio of at least 3 to 1. This ratio is also referred to as the aspect ratio. Some counting strategies placed an upper limit on the fiber width restricting the counting to respirable fibers. Airborne asbestos is controlled by monitoring a sub-population of the airborne asbestos. No asbestos fibers shorter than 5 lm or fibers of any length having widths less than the resolution of the light optical method are counted. In the non-occupational environment, the Environmental Protection Agency requires the use of analytical transmission electron microscopy and fibers and counting fibers with lengths of 0.5 lm or greater and aspect ratios of 5 to 1 or greater are counted. The permissible exposure limit for asbestos has been reduced by more than 120-fold since 1969, when the standard was 12 fiber/ml and the current monitoring methodology was developed. The manufacturing and mining worksites are regulated by two different federal agencies and the asbestos exposure limit was higher in the mining environment until recently (Mine Safety and Health Administration 30 CFR Part 56, 57, and 7, Federal Registry, February 29, 2008). Currently the permissible exposure limit (PEL) is the same in both types of workplace and it is 0.1 fibers per milliliter (fiber/ml) over an 8-h shift as a time-weighted average (TWA). A milliliter (ml) is equivalent to a cubic centimeter (cc) and sometimes this standard is reported as 0.1 f/cc. As the phase-contrast methodology was used to monitor lower exposures and environments, other fibrous mineral particulates were incorrectly characterized as asbestos. These occurred in talc deposits and taconite ores from the Eastern Mesabi Range.

Jan 1, 2008

The title of “the world’s biggest volume-produced hydraulic breaker,” that was held for more than a decade by the Atlas HB 7,000, changed hands with the launch of Atlas Copco’s HB 10,000 at bauma 2007. A service weight of 10 t (11 st) and up to 50 percent higher productivity represent major steps toward a new market segment: the use of hydraulic breakers as cost-efficient production machines for primary breaking and as a true alternative to drilling and blasting. The HB 10,000 has all the technical features developed by Atlas Copco for its hydraulic breakers and includes: StartSelect — the breaker’s start-up and shut-down behavior can be adapted to the conditions. AutoControl that ensures an optimized balance of impact energy and impact frequency to maximize percussive performance. Auto-Control also reduces blank firing force and controls energy recovery. PowerAdapt — if oil pressure is too high, the breaker shuts down automatically. This prevents downtime and is particularly useful when breakers are used on different carriers. DustProtector II — a combination of multiple strippers prevents abrasive rock dust and foreign bodies from penetrating the lower breaker section. Conti- Lube II — the automatic lubrication unit guarantees optimal lubrication of the breaker at all times.

Jan 1, 2007

By Giorgio De Tomi, Ricardo Tichauer

Mineral exploration is a critical step for success in mining. However, small-scale mining often ignores exploration best practices. This paper introduces the Tichauer-DeTomi Matrix, a tool for assessment of geological uncertainty in small-scale mining. This matrix, which measures the level of compliance of exploration programs in small deposits with industry best practices, has been applied to three small mining projects in Brazil: an artisanal gold mine in the Amazon, a small-scale manganese mining venture in the Northeast, and a small manganese deposit in the Southeast. The application of the matrix resulted in indexes that reflect the actual level of maturity of the mineral exploration program in each project. Therefore, the matrix has shown potential to be an effective tool for assessment of the geological uncertainty remaining in small-scale mineral projects, as well as to identify priority exploration activities for reduction of risks associated with the geological uncertainty. As a risk assessment tool, the TichauerDeTomi Matrix may be helpful in promoting investment and sustained development in and around small mines.

By W. H. Langer

At the start of the 20th century Denver?s population was 203,795. Most streets were unpaved. Buildings were constructed of wood frame or masonry. Transport was by horse-drawn-wagon or rail. Statewide, aggregate consumption was less than 0.25 metric tons per person per year. One hundred years later Denver had a population of 2,365,345. Today Denver is a major metropolitan area at the crossroads of two interstates, home to a new international airport, and in the process of expanding its light rail transit system. The skyline is punctuated with skyscrapers. The urban center is surrounded with edge cities. These changes required huge amounts of aggregate. Statewide, aggregate consumption increased 50 fold to over 13 metric tons per person per year. Denver has a large potential supply of aggregate, but sand and gravel quality decreases downstream from the mountain front and potential sources of crushed stone occur in areas prized for their scenic beauty. These issues, along with urban encroachment and citizen opposition, have complicated aggregate development and have paved a new path for future aggregate development including sustainable resource management and reclamation techniques.

Jan 1, 2009

By COLIN A. LAWRENCE, Anthony Del Vescovo

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2017

By Manuel Pérez-Tello, María M. Salazar-Campoy, Óscar Rodríguez-Hoyos

A common problem during the operation of the Kaldo furnace is the formation of accretions and blockage of the injection lance due to splashing. This typically occurs during the processing of anodic slimes for the production of doré. In this work, a 1:7 scale model of the Kaldo furnace currently in operation at Metalúrgica de Cobre, Mexico, was built in transparent acrylic plastic. Water and colored oil were used to represent the doré and slag, respectively. The model was used to determine the maximum penetration distance of the injection lance under a variety of experimental conditions at room temperature. Input variables included two types of oil, rotation speed, inclination angle, and the fraction of the vessel volume occupied by the liquids (φ). A mathematical correlation for the dimensionless maximum penetration distance of the injection lance d ∗ as a function of φ, the Froude number of the liquids in the vessel (Fr), the Reynolds number of the gas jet (Re), and the oil-to-water kinematic viscosity ratio (η)was developed. Reasonable agreement between the calculated and experimental values was obtained. Digital images showed that splashing was caused by the turbulent gas jet impinging upon the free surface of the liquids, whereas the cascade effect was negligible. The results of this work have been useful to improve the operation of an industrial Kaldo reactor.

By Manuel Pérez-Tello, María M. Salazar-Campoy, Óscar Rodríguez-Hoyos

A common problem during the operation of the Kaldo furnace is the formation of accretions and blockage of the injection lance due to splashing. This typically occurs during the processing of anodic slimes for the production of doré. In this work, a 1:7 scale model of the Kaldo furnace currently in operation at Metalúrgica de Cobre, Mexico, was built in transparent acrylic plastic. Water and colored oil were used to represent the doré and slag, respectively. The model was used to determine the maximum penetration distance of the injection lance under a variety of experimental conditions at room temperature. Input variables included two types of oil, rotation speed, inclination angle, and the fraction of the vessel volume occupied by the liquids (φ). A mathematical correlation for the dimensionless maximum penetration distance of the injection lance d ∗ as a function of φ, the Froude number of the liquids in the vessel (Fr), the Reynolds number of the gas jet (Re), and the oil-to-water kinematic viscosity ratio (η)was developed. Reasonable agreement between the calculated and experimental values was obtained. Digital images showed that splashing was caused by the turbulent gas jet impinging upon the free surface of the liquids, whereas the cascade effect was negligible. The results of this work have been useful to improve the operation of an industrial Kaldo reactor.

By Hassell E. Hunter

The Wyoming Mineral-Conoco Crownpoint Project represents the first time that big hole drilling has been exclusively used to develop totally a privately financed mine below a depth of 1000 feet. Three shafts, one ten feet in diameter and two six feet in diameter, were successfully drilled to depths of 2243', 2188' and 2188' respectively and cased with hydrostatic designed steel casing. The largest shaft is to be used to handle muck and water from station excavation and enlargement of the other two shafts. A reverse circulation system with potassium chloride base mud was used for drilling. The mud was cleaned by settling in steel lined tanks with assistance by cyclone type separators. Deviation was monitored by gyroscopic surveying at 30 foot intervals and did not exceed 16 inches off plumb. Casing was designed to withstand hydrostatic pressures with a 1.5 safety factor to the large shaft and 1.25 safety factor for the smaller shafts. All casing welds were x-ray tested prior to lowering the casing in the hole. Cementing the annular space completed the operation. The total time to mobilize, drill and move off the three shafts was 363 days. The drilling operation was completed ahead of schedule and under budget.

Jan 1, 1983

By Graham W. Gibbs

The current state of knowledge concerning mesothelioma risk estimates is reviewed. Estimates of the risk of mesothelioma exist for the commercial asbestos fiber types chrysotile, amosite and crocidolite. Data also exist on which to assess risks for winchite (sodic tremolite) and anthophyllite asbestos. Uncertainty in estimates is primarily related to limitations in measurements of exposure. Differences in the dimensions of the various fiber types and of the same fiber types at different stages of processing add a further complication. Nevertheless, in practical terms, crocidolite presents the highest asbestos related mesothelioma risk. The risk associated with sodic tremolite (winchite) appears to be similar. In chrysotile miners and millers, the mesothelioma risk has been linked with exposure to asbestiform tremolite. Exposure to chrysotile in a pure form seems likely to present a very low if any risk of mesothelioma. While the majority of mesothelial tumors result from exposure to the asbestos minerals, there are other well established and suspected etiological agents. While a practical threshold seems to exist for exposure to chrysotile, it is unlikely to exist for the amphibole asbestos minerals, especially for crocidolite. To date there is no indication of an increased risk of mesothelioma resulting from non-commercial fiber exposure in the taconite industry. © 2007 Elsevier Inc. All rights reserved. Keywords: Mesothelioma; Amosite; Grunerite; Taconite; Crocidolite; Tremolite; Anthophyllite; Winchite; Risk estimation; Etiology

Jan 1, 2007

By John E. Rourke, O&apos

This paper describes some of the results of a project for the design and demonstration of subsidence monitoring systems for underground coal mines. The project was designed to test monitoring systems described in an earlier feasibility report (O'Rourke and others, 1979). General objectives of the project were to develop reliable cost- effective monitoring systems for use above caving- type mining operations, over supported mines, and in urban undermined areas. Topics selected for discussion in this paper include a description of the instrumentation systems, the site conditions, problems of installation, resulting recommendations and an over- view of subsidence performance data obtained. There were some particularly difficult problems of installation to overcome at this site. Some of these could be experienced at any surface or under- ground project, others are probably more directly related to Western coal fields. Almost any subsidence monitoring program may face the following difficulties:

Jan 1, 1982

By G. Budge

In the extractive industry the term ‘continuous improvement’ (CI) usually means procurement of the latest state of the art equipment. This is generally perceived as the only way to add further value to the supply chain, with the driving philosophy of increased tonnage to dilute operational costs. However, not all market places can facilitate this approach. RJB lives in a fiercely competitive market and has targeted the standard efficiency drivers of rationalisation and stock management with a vengeance; and also operate CMMS (Computer Maintenance Management System), RCM (Routine Condition Monitoring)and CBM (Condition Based Maintenance) methodologies. Ultimately though, these systems are only as good as the people who operate and manage them and to add further value without procurement, people must be re-introduced back into the operation. Through TPM (Total Productive Mining), that is what RJB have set out to do.

Jan 1, 2001

By R. K. Sinha, B. S. Choudhary, Desh Deepak, A. K. Mishra, Hemant Agrawal, Shankar Kumar

There are several methods (empirical, statistical, and machine learning tools) to calculate blast-induced ground vibration. Still, due to complications in the blasting procedure, under varying blasting loads and strata conditions, it is not easy to predict and simulate blast vibration precisely. Therefore, a study was conducted to simulate the field blast data in Ansys software using explicit dynamics. For this study, monitoring of ground vibration for 20 single hole blasts was carried out. The density of emulsion explosives was in the range of 0.9 to 1.15 g/cc. In the laboratory, rock properties were determined from the rock sample collected from the mine site before blasting. The in-hole velocity of detonation (VoD) and the density of the emulsion explosive were also determined. These parameters were used for numerical analysis to know the ground vibrations at specified points. The results of ground vibration predicted by the model are validated using field data.

By W. J. Miles

At the beginning of the 20th century, barite was a mineral of minor importance in the United States. Its primary use was to extend lead oxide in white paint. Barite also added the special qualities of hiding power and flatness to paint. Because white lead sometimes turns black or yellow and barite does not, ground barite became a pigment on its own merit. Barium chloride was added to bricks before fi ring to stop efflorescence when exposed to weather. Barium carbonate or nitrate added luster and brilliance to glass. Barium chemicals were added to refining sugar, enameling iron, making oilcloths and paper collars, and in the manufacture of paper, artificial ivory, rubber and lithopone. Lithopone became a major paint ingredient in the 1920s; its use lasted until the 1950s, peaking at 150 kt (165,000 st) of barite in 1937 and 1947 for the manufacture of lithopone. Later in the 20th century, titanium dioxide replaced lead oxide, barite and zinc oxide in the coatings industry. In the 21st century, barite is used as a filler, extender or weighting agent in products such as paints, plastics and rubber. Some specific uses include its use in brake and clutch pads for automobiles, automobile paint primer for metal protection and gloss, to add weight to rubber mud flaps on trucks and to add weight to the cement jacket around petroleum pipelines under water. In the metals casting industry, barite is part of mold release compounds. Because barite significantly blocks X-ray and gamma ray emissions, it is used as aggregate in high density concrete for radiation shielding around X-ray units in hospitals, nuclear power plants and university nuclear research facilities. Ultra-pure barite consumed as liquid is used as a contrast medium in medical X-ray examinations. Barite is the raw material for barium chemicals, such as barium carbonate, which is an ingredient in faceplate glass in the cathode-ray tubes of televisions and computer monitors. In the 21st century, barite industrial uses accounts for an estimated 78 kt/a (86,000 stpy) in the United States.

Jan 1, 2009

By James J. Meadows, Jason D. Pampena, Emanuele G. Cauda, Lauren G. Chubb

Exposure to respirable crystalline silica (RCS) can cause serious and irreparable negative health effects, including silicosis and lung cancer. Workers in coal mines have the potential of being exposed to RCS found in dust generated by various mining processes. The silica content of respirable dust in one single mine can vary substantially over both time and location. The current monitoring approach for RCS relies on the use of traditional air sampling followed by laboratory analysis. Results generated using this approach are generally not available for several days to several weeks after sampling, and this delay prevents timely and effective intervention if needed. An alternate analytical method is needed to reduce the time required to quantify the RCS exposure of mine workers. The National Institute for Occupational Safety and Health (NIOSH) has developed a new method using commercially available portable infrared spectrometers for measuring RCS at the end of the sampling shift. This paper will describe the application of the new field-based RCS analytical process for coal mines, including the use of the new method with the existing Coal Mine Dust Personal Sampler Unit. In a case study conducted by NIOSH with a coal mine operator in West Virginia, field-based RCS analysis was completed at a mine site to evaluate the new technique. The RCS analysis results obtained by the field-based method in this case study showed sufficiently strong correlation with results obtained by the MSHA standard laboratory analysis method to allow the mine operator to use the field-based method for evaluating process improvements.

By Brent A. Elliott, J. Richard Kyle

Texas is a major producer of industrial mineral resources required by the state’s ever-growing population that now exceeds 28 million. Texas typically ranks in the top three states for the value of non-fuel mineral production with a total value of $5.2 billion in 2017, accounting for 6.9% of the total US mineral value. Almost 90% of current Texas industrial mineral value comes from the production of cement, crushed stone, industrial sand, and construction sand and gravel. Construction material consumption is focused in the 25 metropolitan areas of the state with populations of > 100,000 residents. Industrial mineral consumption is dominated by the four most populous regions of the state—Houston, Dallas-Fort Worth, San Antonio-New Braunfels, and Austin-Round Rock—with an aggregate population of more than 18 million. More than 11,000 employees work in Texas mining and processing operations. Texas produces more crushed stone than any other state from more than 200 quarries; a similar number of operations produce sand and gravel. Specialty industrial sand production for use as proppants in hydraulic fracturing for enhanced petroleum production serves as an excellent example of how developments in one industry sector can markedly affect another industry; the production of industrial sand in Texas has markedly increased over the past decade, reaching $1.3 billion in 2014. With Texas’ population projected to reach 50 million by 2050, continuing in-state development and production of industrial minerals will be required to supply its residential, commercial, and industrial users. Favorable geology and economic factors provide opportunities for identification and development of new industrial mineral production sites.