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By L. Buckingham

Barrick Goldstrike Mines Inc. has embarked on a continuous improvement effort to ensure that Barrick Gold Corporation will retain its lead in the gold industry in years to come. The continuous improvement initiative is based on careful mapping of the key levers associated with each activity of business. The individual levers are then evaluated to determine their potential to affect the profitability and safety of the operation. The most promising are diagnosed for root causes. These root causes are then addressed to enhance benefits. Through a structured approach of mapping, brainstorming, evaluating and instigating change with follow up measurement and reporting; Barrick Goldstrike is anticipating an increase in throughput at the autoclave facility of 10% with little or no capital expenditure. The resultant approach to Continuous Improvement will be utilized throughout the Goldstrike facility and then throughout Barrick's world-wide operations.

Jan 1, 2002

By N. Roqueñí, J. Loredo, F. Pendás

Impacts of mining on surface water and groundwater occur frequently not only in active mines but in abandoned mines, then the establishment of effective legal mechanisms for the regulation and control of mine waters is a necessary step in order to avoid pollution from mine waters and in consequence to contribute for a sustainable development of the mining industry. Currently there is a lack of a specific European legislation about mine waters and this absence of legislation occurs too at national level in many European countries. This absence of an European specific regulatory framework for mine water pollution questions the effectiveness and the applicability of the current legislation and this fact has led the EC to put forward proposals legislation to adequately deal with environmental and social consequences of mining, and among those proposals is a draft for a directive on waste from the extractive industry that includes provisions for mine water pollution.

Jan 1, 2005

By H. Nematollahi

The comminution laws The grindability of the ores or minerals is an important factor that could not be deduced from their mineralogical characteristics (Testut, 1958). Many theories have been proposed to determine the amount of work required in a comminution operation as a function of the nature of material, size and shape of the minerals before and after of comminution. The most important laws are proposed by Rittinger, Kick and Bond. According to Rittinger (1867), the work is directly proportional to the new surfaces produced during the comminution. Kick (1885) believes that the work needed to produce similar modification is proportional to the volume or mass of the material. Bond, during his 25 years of experience and research, reached to the conclusion that on the average the energy required for a known comminution is between the Rittinger's and Kick's laws (Bond, 1952). According to Bond's Third Theory, the work input is proportional to the new crack tip length produced during the particle breakage, and equals the work represented by the product minus that represented by the feed.

Jan 1, 1994

By J. C. Willett, J. R. Sanfilipo, S. M. Podwysocki, P. D. Warwick

The U.S. Geological Survey is concluding an assessment of the major coal regions of the country. In this program, the quantity and quality of coals that are expected to be mined during the next 30 years are characterized. For the Gulf Coast region, the evaluation includes reviews of the stratigraphic setting, coal resources, and the quality of the Cretaceous to Eocene coals in four coal-producing areas. The coal-bed methane potential for these areas will also be evaluated. The results of these efforts will be a series of digital maps, text, and tables that will be published in a CD-ROM format.

Jan 1, 2000

By Schebek, J. Warsen

"Data and information from sustainable development (SD) reports can be seen as a promising and easily accessible source for an Life Cycle Assessment (LCA), i.e. for generic Life Cycle Inventory (LCI) data in particular. The reliability and comparability of LCA results crucially depends on the quality of LCI data, that is defined by specific normative requirements. In parallel the GRI (Global Reporting Initiative) provides a set of guidance documents for enhancing the quality, rigor, and utility of SD reporting with specific reporting principles that address similar issues on a company level comparable to LCI data quality requirements on the process level. In order to assess the general suitability of the fundamental reporting principles for LCI data quality purposes selected reports from mining and minerals (M&M) sector are assessed within a detailed analysis."

Jan 1, 2005

By Steven G. Vick

Not too long ago a mill superintendent, when asked where his tailings were being disposed, could simply shrug his shoulders and point to the open end of the thickener discharge pipe. This “out of sight, out of mind” approach to tailings disposal is a practice of the past. Today there are very few planned hardrock or energy-related mining facilities where tailings disposal has not been identified as the major area of impact and controversy. In fact, development of some ore bodies has been stymied altogether by lack of suitable sites or methods for tailings disposal. The bottom- Iine result is that tailings disposal often controls the permitting lead time and has a significant influence on construction cost (up to 2070 in some cases) of new minemill complexes. The following article, the first in a series of three, explores technical background and historical perspectives on siting and design of tailings impoundment facilities.

Jan 6, 1981

By Jean-Michel Rendu

Electronic data processing' is becoming a necessary part of all large mining operations. Accountants, geologists, mining engineers, samplers, and truck drivers are needed to operate a mine. So appear to be systems analysts, computer operators, and software engineers. Trucks, loaders, and drills must be used to extract useful material from the ground. So must be mainframe and microcomputers, plotters, digitizers, and computer terminals. The papers presented in this section describe experience gained in Europe, Australia, and North and South America. The mining and data processing environments and the size of the companies vary significantly, but the conclusions drawn are often strikingly similar. Common answers to often-asked questions can be summarized as follows: - Why invest in data processing? The main reason is that information systems can supply accurate and timely information for better decision-making. Other reasons are mentioned including, to speed-up the processing of large volumes of information, to perform operations which cannot be performed manually, or to reduce costs. But all of these reasons appear ancillary to that of supplying accurate and timely information.

Jan 1, 1989

By Dave Watson

Henderson Mine personnel have more than 20 years experience and have placed more than 400,000 m3 (520,000 cu yd) of shotcrete and concrete. Over the last 20 years, the mine has used a variety of equipment to place concrete, wet shotcrete and dry shotcrete and is constantly trying to cut costs and increase efficiencies. Recently, the mine received a state-of-the-art wet shotcrete placer. The batch plant was automated, and a mobile concrete-form jumbo was fabricated. The mine will also receive a new concrete transport truck. Henderson’s background The Henderson Mine is owned by Climax Molybdenum Co., a unit of Amax, Inc. It is an underground, primary molybdenum producer near Empire, CO. The mill is located between Silverthome and Kremmling, CO and is connected to the mine by 16 km (10 miles) of underground and 8 km (5 miles) of surface track. Except for the ore haulage system which is powered by overhead trolley, all mobile equipment is rubber-tired and diesel-powered.

Jan 1, 1992

One of the core tenets of Sustainable Development is transparency and information sharing, i.e., government and corporate reporting. Governments report on issues within their sphere of responsibility to the degree that their constituents demand that they do so. Firms undertake reporting for two reasons: they are required to do so by law, and doing so makes good business sense. In recent years, stakeholders have come to see themselves as having a right to information about government actions and business operations that have the potential to affect their lives, health, community and environment. As a result, disparate groups, including industry associations, non-profit groups, academics, and individual firms, attempted to lay out what governments and firms should report. There are many types of sustainability reporting. In this paper we focus on three of them that both governments and firms utilize. We discuss the benefits of each. We argue that while the goal of complete and perfect data is not achievable or feasible, sustainability reporting of all three types is necessary to ensure that sound public and private decisions are made.

Jan 1, 2007

By E. Jannoulakis

This paper introduces a practical methodology for analyzing vi¬bration records in view of improv¬ing blast designs and preempting anomalous vibrations. This technique, which is based on empirical data, uses a blasting-efficiency determinator (BED) as an indicator of vibration-energy transmission. The method was tested using data from a blasting event at an open-cast coal mine in the province of New Brunswick, Canada. The results derived from the BED values showed that geology and delay timing were probably the principal factors that induced high-intensity vibration propagation.

Jan 1, 2000

By M. Taxiarchou

The continuously increasing rate of the non-renewable raw material consumption together with the production of immense volumes of solid wastes and effluents is one of the main characteristics of our modern society. This leads to an unconditional necessity to reduce the raw material and energy consumption and to recycle the used materials and products. Life Cycle Analysis (LCA) constitutes a promising tool in this direction. LCA is a methodology, whose main purpose is the objective calculation and analysis of the environmental burdens of products, processes and activities as well as the estimation of the possibilities to perform environmental improvements in combination with the rational use of raw materials and energy. The purpose of this paper is to present the life cycle of marble and granite from the quarrying to the processing stage, including the transportation between the quarry and the processing plant, by quantifying the environmental impacts that derive from each stage and the evaluation of their potential effects to the environment and to human health.

Jan 1, 2007

By C. J. Pritchard

I commend the authors on examining an interesting method of shaft lining and attempting to improve safety in a dangerous environment by remotely installing the shaft lining. It is important, though, to not trade off shaft lining safety for long-term mine safety by lining an intake shaft with combustible material. In many operations, the mine utilities are installed next to the lining of the intake shaft, supplying a possible ignition source if damaged or overloaded. Although the polyurethane studied in the paper is of relatively high density, no mention is made of the flame retardency of the samples. When exposed to heat, small amounts of polyure¬thane will melt and bum but are extinguished when the heat source is removed. If large surface areas of combustible polyurethane - a tunnel or mine shaft - are exposed to ignition heat sources that are not removed or extinguished early, an uncontrollable, fuel rich fire may result with high carbon monoxide levels, low oxygen concentrations, and greatly increased burning rates that can have devastating effects on the ventilation system and miners' safety.

Jan 1, 1990

By Vitaly T. Borisovich

Mining economics courses have been taught in Europe for more than two centuries and in the United States for most of this century. They are the mineral industry's version of engineering economics offered by industrial engineering departments. In the 1930s, mineral economics first appeared in American mining schools. This subject goes beyond the deposit and the mine. It examines the economic aspects of mineral resources in general and the individual mineral industries in particular. In 1947, the first degrees in mineral economics were granted in the United States. There are mining and geological engineers who specialize in mining economics. But it has rarely become a separate degree program. Rather, in this country and several others, a graduate student in a mining department or school will include economics in his course work. Then the person writes a thesis or dissertation on a mining economics topic. One exception is found in Moscow at the Department of Geoeconomics of the Moscow Geological and Prospecting Institute (MGPI). To place this program in perspective, some background is needed on education in the Soviet Union.

Jan 1, 1991

By Gary J. Goldberg

Through the early 1980s, surveying at Bingham Canyon required a great deal of repetitive and manual work. The advent of total station surveying equipment provided an opportunity to improve the speed and accuracy of surveying work while reducing manpower needs. An evaluation was made of total station systems and their ability to meet the surveying requirements of Bingham Canyon. This culminated in the purchase of a total station system as the mine reopened in 1986. The surveying department at Bingham Canyon during the early 1980s consisted of three, four-man crews using theodolites and self-leveling levels to perform the majority of the field work. Office work involved data reduction and hand plotting. Although hand-held programmable calculators were used, a great deal of time was spent manually transferring field notes to final calculations. After shutting down in early 1985, plans for start-up of mining operations in 1986 included a review of all aspects of the operation for cost and productivity improvement. Applying total station survey capabilities offered the potential to improve surveying accuracy and speed while reducing manpower needs.

Jan 1, 1990

By Robert D. Gibson, E. Donald McKay, Paul B. DuMontelle

Subsidence of the land surface in some parts of Illinois is caused by underground coal mining. The U.S. Bureau of Mines is backfilling abandoned mines at selected sites in southwestern Illinois in an attempt to support failing mine openings. The Illinois State Geological Survey assists the Bureau by developing geologic and engineering information. As part of this investigation, television probes of fifteen injection borings in Belleville augmented conventional methods of study. The television probes of uncased sections of borings revealed several phenomena. Water erosion caused shale beds to slough, which partially filled some borings. Fractures caused by subsidence were identified, and excellent views of underground mine workings provided documentation of the mining method. The condition of mine timber was evaluated. Pack walls supported some openings. Both floor heave and roof fall were observed to be causes of failure in the mines.

Jan 1, 1982

By D. W. Boening

Xanthate salts have demonstrated effectiveness as a flotation reagent in the recovery of heavy metals from mining wastewater. However, due to their strong ionic potentials, they are generally toxic to aquatic life. Under ambient environmental conditions, the half¬life of a xanthate is approximately four days. As a soluble salt, xanthates will complex with the metallic ions contained in water and fish. Some researchers have proposed that this complexing may extend the halflife, as well as optimizing the transfer of a given metal from solution across the gill surface. Leakage of xanthate treated wastewater into the surrounding surface waters is the most common route of exposure for aquatic plants, invertebrates and fish. Because this is an emerging mineral-recovery technology, more information is needed regarding xanthate toxicity and environmental fate before environmental impacts can be assessed with any degree of certainty.

Jan 1, 1999

By Edward DeLilla

Formalized technical audits for mining machinery during manufacturing are a fairly new concept to the North American mining industry. Although used extensively elsewhere, especially in Australia, the concept of independent auditing of machinery design and manufacturing has been slow to gain acceptance in the United States and Canada. Simply stated, a technical audit is an independent, third-party review of all or specific portions of machinery design, manufacturing and assembly to verify compliance with purchase specifications and suitability of the machinery for the specified application. If specified correctly, the useful life of different kinds of structural and mechanical components can be extended beyond normally accepted usage. There is no reason why, if properly designed and built for the application, major structural components on mining machinery cannot be made to last for 20 years before being rebuilt. Also, gearing can be made to routinely last for 15 years.

Jan 1, 1995

By Richard Kolada

If the emission of methane into any particular area of an underground coal mine remains constant, then the calculation of ventilation requirements is relatively simple. This is also true if the ventilation system is recirculatory. However, the emission of methane into a working area can vary considerably. There is always a risk that the ventilation will not be able to dilute the emission of methane to acceptable levels, because there are often short-lived peaks of emission which are very large. The ventilation design must therefore consider what is an acceptable level of risks and calculate the airflow requirements to meet this level. The acceptable level of risk can be calculated by examining the historical variation in methane emission into the area to be ventilated. For example, consider that an acceptable level occurs when methane emission peaks only exceed the capability of the ventilation one day in twenty. Then, from the history of methane emission, it is possible to calculate the necessary ventilation requirements. This method has been used since the early 1980s for conventionally ventilated districts. This paper examines the application of this technique to districts ventilated by recirculatory ventilation.

Jan 1, 1987

At present, increasing focus of public perception is placed on the environmental and social benefits, risks and impacts of metals and metal-bearing products. To address these issues, the concept of product stewardship has recently been introduced into the political debate. In this paper, results from a survey of existing environmental and social reporting practice in the copper mining, smelting, refining and fabricating industry are presented. In this context, particular emphasis is placed on the reporting practice regarding products and product performance over the life cycle. In a few companies there has recently been a shift towards adopting product stewardship principles and putting them into action. As part of an ongoing exercise within the Non-Ferrous Consultative Forum on Sustainable Development sponsored by the International Copper Study Group (ICSG) key issues of interest to the non-ferrous metals sector are being addressed. The Forum, for example, has developed a series of principles, criteria and indicators that could form the basis for a voluntary, industry-lead product stewardship scheme. Current achievements and way forward of this product stewardship initiative will be presented.

Jan 1, 2003

By Lynn E. Bowman

Efficient filtration of fine kaolin particles plays a crucial role in the processing of raw kaolin to a marketable product. Filtration can often be the rate-controlling step of the whole process. Consequently, plant production depends on the rates being achieved in filtration. To alleviate the bottleneck in production, Nalco Chemical Co. initiated a reagent development program to chemically enhance the performance of the filtration units. Filter aids of different classes were assembled and evaluated in bench simulations. These included reagents whose primary mode of functionality were coagulation, flocculation, thickening and combinations of each. This article discusses the development and application of a new reagent that improves the filter production rate with minimal impact on filter cake percent solids. Plant data indicate that this reagent can increase production rates by as much as 35% on clays of varying particle size, as well as clays that are calcined. The reagent's impact on solids content, re-slurrying characteristics, Brookfield and Hercules viscosity and drying is within the standards set by plants that evaluated and now use this product.

Jan 1, 1993