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By J. M. Barker, V. T. McLemore

Most discussions of sustainable development (SD) in mining relate to metal mines in rural areas. Industrial minerals (IM) are closer to urban areas primarily owing to a high transport-cost component of delivered cost. This visibility to large populations overshadows IMs relatively small operation size and generally lower waste volume and toxicity. The IM industry needs to rethink its way of doing business to fit into the SD paradigm. Society and business in general will also undergo significant change to enable industrial SD along the lines of triple-bottom-line accounting with government pushing everyone. The benefit to IM mining from embracing SD is a renewal in their social license to operate and a rebirth of mining as a positively-viewed force in society. This positive view would lead to lower acquisition costs because society would not fight so hard to eliminate nearby mining. This would ease the current exploration woes of the IM industry by opening up new deposits for exploration and more readily allowing placement of mines nearer to markets. The earlier in the exploration process SD is initiated, the better.

Jan 1, 2004

By B. Schimm

Improve the mines productivity by simplifying the mining process, for these tasks the Wirtgen Surface Miner offers an attractive alternative. Surface Miners cut, crush and load material in one operation with only one machine. The cutting depth is controlled exactly.

Jan 1, 1997

By J. M. Wempen

As development in underground coal mines progresses away from the critical components of the ventilation system, including the main fans and ventilation shafts, resistance is markedly increased. This results in higher pressure and flow requirements from the main fan(s) to maintain adequate face ventilation, which often requires that the primary ventilation system is upgraded with additional shafts and surface fans. The use of booster fans underground is a potentially practical alternative. This study presents simulations of the use of booster fans in two underground ventilation scenarios, one longwall and one room and pillar. The booster fan effects on the power requirements of the ventilation systems are evaluated.

Jan 1, 2011

By A. L. Anderson, J. T. Rybock

KEECO has developed the Silica Micro Encapsulation (SME) technology for the treatment of acidic, metal-laden waters. Utilizing a silica-based chemical formulation that entails chemisorption and micro-encapsulation of heavy metals in a permanent silica matrix, encapsulated particles settle quickly and are effectively isolated from the surrounding environment, producing a stable sludge that is characteristically non-hazardous. In a number of independently-verified pilot and full-scale applications (including the Bunker Hill Mine, Leviathan Mine, Wheal Jane Mine, and Meldon Quarry), SME has been proven highly effective. The technology has been featured in a number of mining publications and selected for innovative technology awards.

Jan 1, 2000

By William Gleason

"It is safe to say that the coal industry, in the United States and globally, is currently suffering through one of the hardest times in its history.A perfect storm of competition, changing energy demands, politics and public perceptions have collided, inflicting significant harm to the industry that many say is irreparable. This, in turn, has led to massive job losses in some regions, heavy cuts in production and even bankruptcy filings from two of the largest coal mining companies in the nation.Cheaper natural gas can certainly take a large share of the blame for the struggle of coal, as utility companies switch from coal to natural gas for power generation. According to the U.S. Energy Information Administration (EIA) the amount of coal used for electricity generation in the United States is at a 45-year low.November 2015 marked the fifth consecutive month that natural gas was the leading source of power generation in the United States. EIA said generators produced 101,866 thousand megawatt hours (MWh) of electricity with gas in November versus just 87,789 thousand MWh with coal, the lowest monthly level since May 1980 when monthly coal use was 84,884 thousand MWh.According to Robert Godby, director of the Center for Energy Economics and Public Policy at the University of Wyoming, there are a number of factors playing a role in the decline of coal, but he points to the advances in fracking as the tipping point.“A lot of people will argue that regulation is the cause of the decline, and it has played a part, for sure, but the story of the recent past is more about what competition has done to the energy market,” Godby told Mining Engineering. “The war on coal was originally declared by natural gas in 2008.”The price of natural gas, which was at $13 per million Btu before the gas fracking boom, has fallen to as low as $1.68 in December 2015. Likewise, Godby said the cost of wind generation is now lower than the cost of generation from coal and the cost of solar generation is coming down as well. In addition to that, the demand for energy has changed in the past five years with more efficiencies in everything from building design to lightbulbs."

Jan 1, 2015

In 1988, at the request of members of the Society for Mining, Metallurgy, and Exploration (SME) Inc., the president of SME formed Working Party No. 79, Ore Reserve Definition. Its mission was to develop guidelines for the public reporting of exploration information, resources and reserves. These guidelines were published in the April 1991 issue of Mining Engineering (pp. 379-384), and as a document entitled “A Guide for Reporting Exploration Information, Resources, and Reserves” in January 1992. Work continued on an ad-hoc basis until 1996. Working Party No. 79 was then renamed the SME Committee on Resources and Reserves and became a standing committee.

Jan 1, 1999

By Robin P. Gardner

The development and use of short-lived radioactive tracer methods for the on-stream determination of residence time distributions in large-scale ball mills is described. Tests are reported on a pilot-plant ball mill with 0.43 m diameter and 0.86 m length and on an industrial mill with 1.83 m diameter and 2.74 m length. Tests with different tracer feed sizes indicate that the residence time distributions on both mills are independent of charge particle size. Similar tests are planned for a-large ball mill of 4.57 m diameter and 9.30 m length. No safety problems were encountered in these tests and none are anticipated in tests of the larger mill.

Jan 1, 1978

By L. Lipsett

"Human rights can contribute to sustainability in the mining sector, both in theory and in practice. Both human rights and sustainability share a common concern to improve economic prosperity, environmental health and social equity by avoiding negative impacts and conflict, as well as by engaging with and empowering affected communities. Globally, there is an emerging consensus that companies have a responsibility to respect international human rights standards. Respecting human rights means that mining companies are responsible to ""do no harm"" to the people and communities affected by their operations. After a discussion of the Protect, Respect and Remedy framework for business and human rights, this paper illustrates some examples of how international standards for human rights and sustainability interacted in a recent assessment of Goldcorp's Marlin Mine in the Western Highlands of Guatemala. The final section explores how human rights should be integrated into broader policies and procedures for corporate sustainability. This includes integrating human rights into ESIA processes, legal compliance, corporate governance and grievance mechanisms. Pressures on mining companies to respect human rights will not disappear; therefore, a proactive and integrated approach to human rights is a fundamental component of a broader strategy for sustainability"

Jan 1, 2011

By Gary W. Hudiburgh

The gangue in some magnetite ore bodies contains feldspar; the alkali content of the feldspar reduces the usefulness of these iron ores. One method of decreasing the feldspar content in magnetite concentrate is froth flotation. The amine flotation of feldspar from magnetite concentrate was investigated using zeta potential measurements, Hallimond tube flotation tests and laboratory-scale flotation tests. The zeta potential of various feldspars (microcline, albite, anorthite, oliqoclase and anorthoclase) were determined as a function of pH; the point of zero charge ranged from pH 1.4 to 2.5. Hallimond tube flotation tests using two amine reagents were conducted on the feldspars. Hallimond tube flotation tests using six amine flotation reagents were performed on the cobber tails (quartz, albite and microcline) from a magnetite concentrating plant; in all cases, over 85 percent flotation recovery was obtained at pH 8 and 10-5 to 10-4 [M] collector addition. Laboratory-scale (667 grams) flotation tests were performed on the magnetite concentrate in an attempt to float the feldspar which had reported to the concentrate. The effects of three different collectors, two levels of collector concentration, three pH levels, starch and HF acid were investigated.

Jan 1, 1975

By G. France

The Blair Athol Coal Mine (BAC) is a large open cut operation in the Bowen Basin of Queensland, Australia. Current mine capacity is about 11 million tonnes per annum(Mtpa) of export coal. On-line analysis at BAC consists of two Coalscan 9500s installed directly on the output of the crusher plant and immediately before the product stockpiles, while a third Coalscan 9500 is installed on the transfer conveyor feeding the train loading bin. The two product Coalscans have a dual purpose. The first is to provide real time coal quality data directly back to the mining operations. The second is that of modeling the product stockpile with accurate on-line information. This modeling enables both production and coal quality personnel to accurately examine the coal quality of each stockpile with a degree of resolution which previously had never been achieved.

Jan 1, 1999

By W. J. Kennedy, John D. Gardner

Introduction During the past 10 years, energy costs in mining have risen from about 4% to as much as 25% of total production cost. When combined with declining ore grades, these costs exert inordinate stress on mine productivity. Industrial engineering techniques have traditionally been aimed at improving manufacturing facilities productivity, but they have been applied to mining as pressure for productivity improvement has increased. These techniques can perform four useful functions for mining operations by improving methods, equipment selection procedures, energy use through scheduling, and managing energy costs rather than being managed by them. This article discusses some of the standard techniques for productivity improvement, and how they can be adapted to perform these four functions. Pre-Production The best time to seek high productivity is when a mine is being planned. During pre-production, when most options are still open, an optimum mine design is achievable. At this time, major equipment selections are made, the layout, material handling systems, and processes are designed, and critical energy source decisions are made. By including explicit energy cost projections, decisions can be made that will save significant amounts of money per ton of ore over the life of the mine. Attention can also be given to often overlooked details such as lighting. Some of the same tools used in new mine planning are applicable to productivity improvements at an existing plant. These tools are the charting and modeling methods that have been developed by industrial engineers over the past 75 years. Energy Consumption Before any analysis of energy consumption can be performed, preliminary work is necessary to find the kind of energy used, how much it costs the plant, and when electrical peaks occur. Past bills should be examined to determine the monthly consumption rate and the cost of each energy type. These data should be adjusted to remove effects caused by production fluctuations or weather. Knowing when electrical peak demands occur is necessary because these determine either the electrical capacity needed or the amount that must be bought. At $500-$800 per kW for construction or $5-$15 per kW per month for purchase, they represent a significant cost. By the time these data are collected, planners should be aware of the importance of energy in the total cost of mine operation, and should have the most crucial time data for electrical peak demand. Flow Process Chart Reducing costs can be accomplished by a thorough look at mine systems and how altering one system causes changes in others. By developing and exercising models of production processes outward to the transportation of the final product, otherwise obscured weaknesses may become apparent. There are tools available for analyzing the mine and its associated systems; one of the most useful is the flow process chart. The flow process chart gives a system analysis of a production procedure by classifying all actions into one of five types: operations, inspections, transportation, delays without paperwork, and delays with paperwork. Operation: In an operation, the nature of something is changed. Examples are blasting, washing coal, and processing matter. Denoted by 0. Inspection: Examining an object for identification or to measure some attribute. Examples are determining whether a drill hole is deep enough, deciding how far to cut under an unsupported roof when operating a continuous miner, or checking the lubricant level on a truck. Denoted bye. Transportation: Moving an object from one place to another. Examples are transporting overburden, moving coal on a conveyor belt, and pumping water. Denoted by =>. Delay without paperwork: A delay that is an inherent part of the system. Examples include idle time of a continuous miner while waiting for shuttle cars or for roof bolting, crushed ore in a storage area waiting for grinding and flotation, and people from one craft waiting for another craft to finish. Denoted by D. Delay with paperwork: A delay that can be terminated only by some written authorization. Examples are coal that cannot be removed until authorized by a bill of sale and transportation orders, personnel records, maintenance, or spare parts. Denoted by V. In practice, the flow process chart is completed after data collection and a detailed examination of the process. Data collection is needed to answer questions on distance, quantity, and time for each of the operations. As the analysis is being performed, each step of the process is subjected to these questions: • Why is the step necessary? • What is being moved? • When does the step take place, and why?

Jan 11, 1983

By B. Law, M. Menabde, B. Baird

Blasor is a new mine planning tool which is being used in the long and medium-term optimization of multi-open-pit operations throughout BHP Billiton’s Base Metals and bulk commodities portfolio. It is not just a scheduler, nor even only a schedule optimizer—although this function lies at the heart of the tool’s functionality—but a pit development plan optimizer, used from ultimate pit design and process plant capacity sizing right through to mining phase design and optimal panel scheduling. The tool uses a mixed-integer-linear-programming optimization engine to determine when material should be excavated and where it should be sent to optimize discounted operating cash flow over the life of operation. The core software design concept of Blasor is to provide a tool which is intuitive and flexible enough so that a competent mine planner can perform a pit development plan optimization without assistance from optimization specialists. To this end, a generalized graphical user interface has been implemented which allows full configuration of the optimization problem, including the definition of all inputs and constraints, specification of the material flow topology, bin and destination class definitions and full specification of the economic model encompassing prices and costs. This paper describes the capability of Blasor and outlines the design concepts underlying its design philosophy.

Jan 1, 2007

By J. Gentry

Chemical grouting has been successfully used for over forty years to control the movement of groundwater in a wide variety of applications including tunnels, subway systems, sanitary sewers, mines and construction projects. This paper illustrates the versatility of chemical grouts by reviewing three projects where chemical grout was utilized to address some very difficult water control challenges. The featured product is acrylamide which can be used alone or in conjunction with other types of grout such as cementitious products. Acrylamide grout is injected as a two component product that will react and form an impermeable gel when the components combine. There are notable differences between the acrylamide based products and cementitious products. The most notable and significant difference is that acrylamide is a true solution grout that contains no particulates and has a viscosity of 1-2cps. This feature enables the acrylamide grout to penetrate very small geological features that other grouts could not penetrate and to seal small cracks and fissures where groundwater seepage is occurring. The product also has an adjustable gel set time from a few seconds to several hours which enables the operator to determine the product travel before it forms a gel. When properly applied the product has a half-life in the soil of 362 years (per testing by the US Department of Energy).

Feb 27, 2013

By R. Tamblyn

Vertically stirred media mills are a highly effective low-footprint solution for the ultrafine grinding of industrial minerals. This work investigates the effect of media density on flow patterns within the mill. Direct irradiation of a media particle leads to decay through positron emission, consequently forming two anti-parallel gamma rays, which allow for the real time tracking of particle position. Grinding media of the same size, but with a range of specific gravities are followed using this method, and the effect on the flow within the mill is revealed. The technique is seen to be an effective method to highlight the velocity profiles within the mill, as well as the zones where grinding is less efficient ? areas of relatively low velocity and high residence time. The changing media is seen to effect the overall flow patterns within the mill, having consequential effects on the efficiency of the grind.

Jan 1, 2009

By C. Asgaard

Asset availability has been a longstanding objective in mining and mineral processing plants around the world. Enormous resources in both dollars and manpower are invested in improvement efforts to achieve higher asset availability. One dimension of asset availability is the time equipment is out of service for large scale planned maintenance activity: grinding mills, kilns, furnaces, mobile equipment, shovels and draglines are all regularly taken out of service for extended repairs and service. The speed, cost and quality of these planned outages provide an opportunity to increase asset availability. Equipment shutdowns are projects that are executed in a compressed time period. This paper will describe how the overall time and cost of equipment shutdowns were significantly reduced at Cliffs Natural Resources Michigan Operations (CNRMO) through the introduction of the Critical Chain Project Management techniques.

Jan 1, 2009

By C. R. Hairfield

With ever rising energy costs, it is increasingly important for mines to operate with energy efficiency. As a large portion of a mine?s energy consumption is often attributed to the operation of mine ventilation fans, maintaining an efficient ventilation system is a critical pro-active way for mining companies to reduce power costs. A common way to measure a mine?s ventilation system efficiency is to calculate the volumetric efficiency, which is simply a calculation of the percentage of total mine air that is usefully employed for production. The purpose of this study is to document a nationwide comparison of the volumetric efficiency of U.S. underground coal mining operations. The results will aim to show just how efficient today?s coal mine ventilation systems are and what factors may be causing their various efficiencies and inefficiencies.

Jan 1, 2009

By S. Möllerherm, E. Drüppel

"The development of indicators to assess the sustainability of mineral raw materials operations is amajor task with respect to its actuality and difficulty. This holds true even more when dealing withenvironmental indicators.The use of existing environmental indicators in the mineral raw materials industry leads to false orat least distorted results. Therefore the Institute of Mining Engineering I from the RWTH AachenUniversity developed indicators and an assessment system for the mineral raw materials industryon operation, company and sector level on behalf of the Federal Ministry of Economics and Labour(Bundesministerium für Wirtschaft und Arbeit, BMWA) and the Federal Institute for Geosciencesand Natural Resources (Bundesanstalt für Geowissenschaften und Rohstoffe, BGR).In total 30 indicators were defined and designed to assess the performance of the mineral rawmaterials industry in terms of sustainable development, 10 indicators for each pillar (economical,ecological and social pillar).The following paper describes some of the results focussing on the development of environmentalindicators. These had to be adapted or completely new designed in order to match the specificcharacteristics of the mineral raw materials industry."

Jan 1, 2005

By R. A. Reiley

Introduction Democratic countries are founded on the principle that all citizens have the right to participate in policy setting and decision-making processes. Citizen participation is especially evident in environmental issues and policies. In the United States, there are currently over 10,000 environmental organizations and new ones are being formed each year. Many of these organizations are formed on a watershed basis and are particularly concerned about the impact mining has on the environment. While the environmental issues vary from area to area, most concerns center around mining impacts related to subsidence, water pollution, and water diversion. Citizens have a number of avenues for participating in lawmaking that affects the mining industry. Some of these avenues include participation in litigation and citizen ballot initiatives. In addition, there are less formal methods of participation that include attending public meetings, commenting on agency rules or lobbying on specific legislation. The intent of this article is outline the various public participations mechanisms, highlight the latest legal developments that have affected mining industry through citizen participation, and briefly discuss emerging issues.

Jan 1, 2001

By E. Tulcanaza

M.S. Azun I do not at all agree with the basic points of the author's conclusion. The use of lognormal or normal model to respond to the attribute distribution function should be carefully questioned. If fitting a distribution function of regionalized variables is the main purpose, one may employ one of certain well-known families of distributions, such as Tukey's lambda functions. For instance, the distribution function of gold assay values studied by Krige (Krige, 1978) may fit the lognormal model well, but one should not exclude that the basic idea of using the distribution function of observed data is to have insight of the physical mechanism that gives rise to the regionalized variables. In Applied Geostatistics, there are many examples considering only lognormal or normal model for the distribution function of geostatistical data even if the observed distribution function has more than one mode. Of course, using lognormal or normal model always brings easy computation for the statistical properties of attribute under investigation. Still, I object to adopting any of those models without having any "statistical inference." As seen from the author's paper, lognormal and normal model produce the same average grade (0.746% copper) and almost the same sample variance. Therefore, which model explains the probabilistic behavior of ore deposit is always an important question that should be replied by the geostatistician using not the common sense but the statistical and probabilistic methods. For kriging procedures, such as linear kriging, one should describe either second order stationary properties or bivariate properties of regionalized variables. Second order properties, such as correlogram function or semivariogram function, are the inputs of the so-called kriging equations. Selecting one of any useable models for the observed second order properties, such as spherical model, is not easy since the models are not based on the correlations structure of the regionalized variables. How those models being used in Applied Geostatistics can be distinguished is another important problem. One may develop many fitting models to respond to the observed second order properties of regionalized variables. However, I suggest that the model should be based on the probabilistic behavior of geologic process. The author used spherical model for copper, wolfram, and silver grades from isotropic sector (Fig. 2, 4, 3b) and exponential model for silver grades obtained along raises in isotropic sector (Fig. 3a). It seems that those semivariograms given in Fig. 3b for isotropic sector and Fig. 4 may be described by the random model implying that regionalized variables do belong to renewal process (Azun, 1983). If I knew the total number of data points used in estimation, I may prove that my conclusion is correct. Recalling the test for the first order sample correlogram value, the test procedure is introduced such that the independence is rejected if [ ] where Za/2 is the a/2 percentile of standard normal random variable and N is the total number of samples used in estimation (Azun, 1983). For the other observed semivariogram functions I suggest the author might try to use the so-called "Markovian model" describing not only the correlation structure of regionalized variables, but also the physical mechanism that produces the regionalized variables. The Markovian model for correlogram function is, [ ] The Markovian model for the other second order properties of ReV are also derived. T ve B, in the above equation, show, for example, structural change and mineralizational variation in a considered deposit, respectively (Azun, 1983). In selecting any model, it is not easy to search for the "best" response to the observed second order properties of ReV's. The Markovian model, based on a theoretical understanding of underlying mechanism, gives more information about the occurrence of regionalized variables and respond to all properties. Random model and the so-called hole effect structure can be easily defined as a special form of the Markovian model (Azun, 1983). An estimation of any second order properties of regionalized variables may be computed through (N-1) lag. However, the dependency between the regionalized variables may be deemed to have "died out" after the so-called stationarity width (range). In practice, the estimation is carried out through 25% of the total number samples available. Therefore, the large fluctuations around the zero level and variance for correlogram or covariogram function and semi-variogram function, respectively, cannot be observed. Since the number of pairs involved in the estimation of higher second order properties is small, the estimation variance at those lags is large. There is no need to show higher order estimated second order properties. After using one of any kriging procedure for block estimation, the distribution function of average grades has the same mean as the drilling sample grades but

Jan 3, 1985

Over 800 mines have closed in Australia in the past 25 years. This paper summarizes the data obtained from those closures and includes all Australian States and Territories and all commodities, including metalliferous, coal and industrial minerals. Twenty five percent of the mines closed due to resource exhaustion or depletion; 24% due to high costs, price drops, or declining grades; 8% due to open pit resource depletion (but with underground reserves remaining) or underground reserves depleted (but plans to open cut remainder) and 7% due to receivership or voluntary administration. The environmental, social and economic impacts of these closures are also significant and include acid mine drainage and impact on mine employees. An understanding of the causes of premature mine closure will better equip mining companies and governments to better manage future mine closures, wherever in the world the mines are operating.

Jan 1, 2007