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By Gary L. Stecklein

This final report delineates the findings of the test programs, simulations, and analyses performed to determine the requirements for the effective application of berms and guardrails as truck restraint systems for elevated mine roadways. Included arts criterion for effective vehicle restraint for guardrail applications and recommendations for berm applications based on scale model tests and computer simulations. Full scale haulage vehicle-berm interaction field tests were performed to correlate the results of these model tests and computer simulations. Recommendations for the construction of berms were made on the basis of tests of berm bearing strength, response of the vehicle to different berms, and predictions based on the obtained correlation

Jan 1, 1981

By I H. Wilson

After decades of turmoil, Rwanda launched its Vision 2020 in 2000 aimed at reconstructing government and addressing poverty. Implementation focused on the agricultural sector, infrastructure and education. Later economic development and poverty reduction strategies recognised that expansion of tantalum, tin and tungsten mining could potentially diversify Rwanda’s economy and improve the balance of trade. In 2005, comprehensive environmental legislation requiring environmental impact assessment for all new mines was introduced. Since 2006, government-operated mines have been privatised and illegal artisanal miners encouraged to form cooperatives. The government passed a new Mining and Quarry Exploitation Law in 2008 and approved a new Mining Policy in 2010. This policy was influenced by the Africa Mining Vision (AMV), which the African Union approved in 2009 to ensure African countries obtain reasonable benefits from exploitation of their mineral wealth. The Rwandan mining industry has grown significantly over the last five years and the second economic development and poverty reduction strategy, released in September 2013 forecasts a further three-fold increase in production in the next five years. The strategy prioritises the mining industry and proposes new legislation, better information, greater transparency, encouragement to investment and use of best environmental and technical practices. It also proposes that Rwanda develop a ‘green’ mining sector featuring a ‘model’ mine that is fully funded through green investment and incorporates renewable energy systems, water treatment systems, forestry schemes and local training. Many international development partners have contributed to the current legislative framework and are monitoring environmental and social performance of mining in Rwanda. Local communities have generally benefited from mining and the new mines show improved environmental performance. The major challenges are dealing with the legacy of past haphazard mining practices and establishing linkages between the mines and local industries to create broader economic development.CITATION:Wilson, I H, 2014. Rwanda and the Africa mining vision, in Proceedings Life-of-Mine 2014 , pp 427–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By AIME

SUPPLEMENTING surveys of the engineering profession regarding salaries and advancement, based upon data from individual engineers, a survey through a questionnaire to employers of engineers has recently been made by a subcommittee of the Engineers Joint Council's Committee on the Economic Status of the Engineer. Its object was to learn directly from employers their attitudes and policies pertaining to the selection, training, placement, advancement, guidance, and professional activities of engineering graduate employes. The questionnaire was sent in May 1946 to 174 employers of engineers, including colleges. Replies were received from 104 employers in nineteen fields of industry, who employ about 2,000,000 persons, about 40,000 of whom are engineers. The following general observations are based on the questionnaires returned. Who Are Hired? Of the co-operators 96 per cent employ cadet engineers directly upon graduation from engineering schools, but only 4 per cent recruit their engineering staffs exclusively from the new graduates. About 43 per cent hire more than half of their new engineer employes after one or more years' experience with other employers. This is evidently a matter of necessity or expediency rather than preference, because more than sixty per cent of those reporting indicate that they prefer to hire the new graduate.

Jan 1, 1947

By Diane M. Doyle-Coombs

In late July 1985, air samples from a sealed portion of the Quinland coal mine in West Virginia showed the presence of carbon monoxide (CO). Mine Safety and Health Administration (MSHA) personnel concluded that a fire was burning behind the seals. Since an imminent danger existed, the mine operator was given a closure order. The gases behind the seals were monitored and almost 2 million ff of carbon dioxide (C02) gas was pumped into the sealed area to stabilize the environment. Sixteen days after the closure order was issued, MSHA allowed the mine to return to production. Approximately 1 yr later, mine management submitted a seal breaching request to MSHA in order to drive a set of entries to further develop the mine. The Bureau of Mines established a sampling strategy and monitored gases from behind the sealed area during the breaching operation until the atmosphere was safe. This report is an account of the seal breaching conducted by the mine, MSHA, and the Bureau. The logistics of this event, the sampling strategy, and the equations applied could be used by the mining industry in future breachings or mine recovery operations. Time to reenter the area was calculated by using the methane (CH4) concentrations sampled at the discharge of the seals. Tracer gas was used to verify the ventilation flows through the area.

Jan 1, 1988

By Walter D. Holland

This instructors guide is intended for use in a course which teaches metal and non-metal mine inspectors to perform surveys for inhalation contaminants in above ground metal and nonmetal mine work areas. The handbook entitled "Handbook for Surveys of Inhalation Contaminants in Above Ground Metal and Nonmetal Mining and Processing Work Areas? is used as a manual during the course. The manual contains a survey check list, rules for determining if sampling is required, a list of most frequently encountered contaminants, a list of candidate contaminants and their sampling conditions, and a description of control procedures and devices. There are several experiments in this guidebook which the trainees perform to acquaint them with the sampling systems.

Jan 1, 2011

By D. C. Kaliampakos, A. K. Moutsatsou, J. K. Skotaras

The wastes from marble extraction in the Thasos- Kavalla-Drama region of northeastern Greece could be utilised as a new source of high-quality white carbonate fillers for the European market. Large deposits, satisfactory properties, acceptable processing costs and environmental benefits are among the factors that would have a positive bearing on a proposal for their use in this way. DTH, the waste arising from dolomitic marble quarrying operations on the island of Thasos, appears to be the more suitable material than DA waste from Nikissiani on the mainland because of the lower cost of primary grinding and the higher production rate of ultrafines with a mean particle size of 5 micrometres (the optimum size for filler properties in the case of both DTH and DA), its superior whiteness, the benefits that such use would bring to a very severe and complex environmental problem and the lower transport cost

Jun 18, 1905

By D. P. Tripathy

A supply chain encompasses all the activities associated with the flow and transformation of goods from the raw materials stage(extraction), through to the end user. Supply chain management (SCM) is the integration of these activities through improved supply chain relationship, to achieve a sustainable competitive advantage and it rests on its ability to provide the right goods and services when and where needed. The supply chain is the vital component of any company?s value chain which links the operating processes to its supplier and customer. The globalization of business promises to offer new and unique challenges for the supply chain competencies of most firms. Challenges will also increase in the environmental aspects of supply chain often referred to as ?Green Issues?. The supply chain of mining industry comprises of the flow of material and information from the mine site, to processing and loading for transport, to the customer. However, due to recent changing environmental requirements affecting mining and mineral processing operations, increasing attention is given to developing environmental management (EM) strategies for the mineral supply chain. This paper focuses on: ? Environmental factors leading to the development of an extended environmental supply chain, ? Additional challenges presented by the extension, ? Performance measures appropriate for the extended supply chain, ? Developing a general procedure towards achieving and maintaining the green supply chain.

May 1, 2006

By Marco Muñoz

La mina Porvenir, perteneciente al Grupo Milpo, está ubicada en Cerro de Pasco, destacándose por la corporación de equipos de alta tecnología minera adecuada a sus operaciones. En ese sentido, el presente texto señala el sistema de gestión operativa aplicado en la mina Porvenir con el objetivo de apoyar las operaciones, ya que la tecnología de información permite manejar complejidad y mejorar la calidad de las decisiones.

Jul 17, 2000

By M. H. Rogers

Coal has been at the forefront of mankind?s drive to improve his quality of life and also for sustainable development, from the Industrial Revolution onwards. The international coal industry today is large, with some 3,7 billion tons being produced and consumed in 1997. South Africa is an important participant in the coal industry, selling some 220 million tons in 1997 of which 64 million tons were exported. It is the second-largest thermal coal exporting country in the world. Despite the size of the world coal industry, it is not immune to change. The address examines growth projections for the industry and the change drivers that will impact on it in the future. Environmental pressures, the most important of which being the climate change debate, the Kyoto Protocol arising from this debate and the development of clean coal technologies, to reduce the impact of coal production and usage on the environment are considered. Other major change drivers considered are competition from other sources of energy and that between coal producers, the deregulation of the electric power industry, corporate restructuring and for the South African producer, legislative reform. The declining (real term) coal price, the consequent squeeze on margins and the need for producers to actively contain costs is covered. Technology has, in the past, been the driver behind the growth and change of the South African coal industry and its future role in ensuring that coal is the fuel of choice for continued improvement in standards of living and economic development is addressed.

Jan 1, 1999

By Pertti Paavola, Hikki Rasanen

This paper describes a very exacting tunneling project. Planning and technical realization of this service and transportation tunnel was especially difficult as a matter of vibration control, because the tunnel is situated only a few meters under Maria Hospital, which is one of the most busiest hospitals in Helsinki. In this hospital there are many departments for bedpatients, research and treatment with high-tech equipment, operational surgery and a big laboratory. Besides access tunnels are situated near several apartment buildings. The functionality of the tunnel required the placement of the access tunnels to be straight towards these apartment buildings for which special care for blast induced air pressure had to be taken.

Jan 1, 1997

By Lon D. Santis

This paper summarizes explosives transportation incident and accident data collected by the U.S. Department of Transportation (DOT) from 1993 to 1998. The paper briefly describes the legislation and regulations that cover hazardous materials transportation. The multimodal incident data collected by the Research and Special Programs Administration (RSPA) contained 86 incidents involving Class 1 materials during transit. Thirty-two occurred on public highways. The Federal Highway Administration (FHWA) data showed there were 8 1 motor-vehicle accidents involving explosives. The FHWA Crash datafile extract contained 649 records categorized as involving Class 1 materials although closer analysis revealed that nearly 90% of these did not involve explosives. In both databases, there were no fatalities caused by the explosive materials although 7 fatalities were the result of injuries suffered during the motorvehicle accident. There were also no serious explosions during any of these incidents or accidents. The paper concludes with an analysis of the risk involved with transportation of commercial Class 1 materials on the highway.

Jan 1, 2000

By Y Xie, L O’Connor, S C. Dominy

Sheeted vein gold deposits are characterised by multiple subparallel veins and often free milling gold. Variability in gold grade and recovery parameters are enhanced by poorly designed sampling and test work protocols. Poor quality samples generally equate to an enhanced nugget effect. A sample can be described as being representative when it results in acceptable levels of bias and precision. Total sampling variability can be quantified by the relative sampling variance, which measures the total empirical sampling variance influenced by the heterogeneity of the lot being sampled under the current sampling / test work protocol. Effort should be made to minimise the relative sampling variance through Theory of Sampling (TOS) and quality assurance / quality control (QA/QC) application. This contribution reports on a case study that exemplifies how high-quality grade and recovery data can be gained from a well-designed and planned drilling, sampling and test work program, followed by bulk sampling. Results across historical resource drilling, geometallurgical drilling, laboratory assay / test work, geometallurgical modelling and a bulk sampling/pilot processing study are reconciled. A whole core, entire-sample test work protocol was used to acquire fit-for-purpose gold grade and recovery data for inclusion into a Pre Feasibility Study reported in accordance with the JORC Code.CITATION:Dominy, S C, O’Connor, L, Xie, Y and Glass, H J, 2017. Geometallurgical sampling protocol validation by bulk sampling in a sheeted vein gold deposit, in Proceedings Eighth World Conference on Sampling and Blending , pp 185–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By M. S. Klima, A. Simard, M. L. Turek

Laboratory testing was carried out to evaluate several devices for recovering clean coal from bituminous coal refuse material. The bulk of the testing focused on using a dense-medium cyclone to process -0.6-mm refuse material. A hindered-settling column and a spiral concentrator were also used to process 1.2x0.15-mm material. Product yields and ash contents were obtained for all tests, while partition curves were generated for selected tests from which the characteristic performance parameters (relative density of separation and probable error) were determined. The results indicated that the dense-medium cyclone was capable of cleaning down to 0.037 mm, while the other devices were effective to 0.15 mm.

Jan 1, 2002

By Vincent Menard

The purpose of the present work is to demonstrate the removal of manganese from a neutral leach zinc-rich solution ([Zn] =150 g/L) at 80°C by oxidative precipitation using a gas mixture of sulphur dioxide (SO2) and oxygen (O2). In order to determine the optimum conditions for manganese removal, several bench-scale semi-batch experiments were performed, where the effects of ORP and gas mixing were investigated. These tests showed that SO2/O2 is a fast and effective oxidant for removing manganese down to ppm level as long as the appropriate ORP is attained/maintained and gas transfer kinetics are optimized.

Jan 1, 2006

The modern theory of sampling of particulate minerals essentially consists of a recent generalization of the procedures for applying and calibrating the formula usually known as ?Gy?s Formula? for sampling variance control, in which the central concept is a parameter called the liberation factor l. A model which can be experimentally adjusted was proposed by one of the authors several years ago, based on geostatistical considerations. This new model, which relates the liberation factor to the sizes of the fragments and mineral grains, solves the usual difficulties faced in the past, and permits predictions that are well verified in practice. Unfortunately, an older, arbitrary and less general formula is still widely used. The vast majority of today?s misapplications of Sampling Theory of Particulate Materials can be traced back to the use of this antiquated and generally incorrect model. Following a brief history of the models used for the liberation factor and a description of its main variable, the liberation size, and to illustrate the importance of proper modelling of l, this paper presents demonstrative calculations of the absurdity of the incorrect model using the particular case of gold mineralization as an example, followed by some more positive examples of application.

Jan 1, 2002

The Pogo Mine, near Delta Junction, Alaska is a new 2500 STPD gold operation. The control system of the mine and milling operations are a hybrid of DCS (Distributed Control System) control and PLC (Programming Logic Controller) control. A DeltaV DCS system serves as the main control and operation platform while the PLCs operate a multitude of vendor specific packages. The communication backbone of the DCS system is a hybrid of star and ring fiber optic topology, which provides reliability and flexibility. The communication between the DCS and PLCs is typically facilitated by serial communication. This communication insures the integrity of the whole control system.

Jan 1, 2008

Frothing in Seawater Flotation Systems

Sep 13, 2010

By D. Harrington

Seldom, if ever, has any mining hazard presented itself that some method has not been devised to control it to some extent; the degree of success of such control depends largely upon the intensity of desire to prevent suffering, injury, and death. The economic saving to be realized and the more definitely this is realized by all concerned, the more quickly and effectively will the hazards be handled is an important incentive to prevention of accidents. Preventing coal-mine explosions is by no means a complex problem; all that is necessary is sensible, conscientious, sustained effort. The fact that explosions can be prevented has been well-demonstrated by the record of the post few years; the average annual death toll from explosions for the 5 years 1906-1910 was 438, and for the 20 years prior to 1929 it was 265: during the past 4 years an average of only 32 deaths per year resulted from this cause, although the annual production during that time varied but slightly from that of 1906-10. This is a truly remarkable reduction, and if other types of mine accidents had been reduced in the same ratio only about 300 would be killed annually in our mines instead of the nearly '1,300 killed in 1936 and the approximately 2,000 killed annually for many years. Although frequency of occurrence of explosions has not lessened greatly during the last decade, their severity decreased markedly, which would indicate that effective means are being taken to prevent the spread of explosions, even though ignitions and their causes are not being handled nearly as effectively as they might or should be handled. Several large coal-producing States, which in the past have experienced numerous disastrous explosions, have been free from such disasters for continuous periods as long as 8 years in the relatively recent past. The application of rock dust to underground surfaces has been an important factor in preventing widespread explosions; some of the mast dangerous mines have been rock-dusted fairly adequately, and this has been amply repaid in the reduced severity of explosions, as heretofore indicated; however, many have applied rock dust apparently without giving much consideration to the amount required to prevent

Jan 1, 1938

In this paper, uniaxial compression tests were conducted on intact rocks and broken rocks that were reinforced by grouting, and the effects of grouting on the strength of broken rocks were analyzed. The results show that after grouting reinforcement, the bearing capacity of broken rocks with different lithologies increased, and their uniaxial compressive strength recovered by approximately 6%–16%. The results indicated that the stronger the rock, the smaller the strength recovery of the consolidated body formed after grouting. At the same time, using borehole camera observation and deep overburden strata separations, the fracture development characteristics of surrounding rocks of the gob-side retained entry were analyzed and divided into different regions. On this basis, a guided grouting method was proposed; that is, shallow hole grouting was first used in the plastic zone of the broken surrounding rocks to form the isolation layer, and then deep grouting holes were arranged in the elastic-plastic zone of the transition zone to guide the slurry flow to the shallow unfilled zone. Therefore, the broken surrounding rocks were reinforced into an integrated body and selfbearing capacity improved.

Jul 28, 2020

By Scott A. Shuey

Keywords: E-Waste, Pyrometallurgy Many might think addressing the issue of e-waste is a new area of study. Electronics disposal has been discussed in some circles for at least the past 25 years. The recycling of electronic waste (e-waste) tends to be a rather complex undertaking when considering the intimate bonding of materials in the average printed circuit board. The development of a recycling process is further complicated when considering the wide variety of products being generated under the heading of ?electronics.? Focusing only on the primary constituents (polymers, Cu, Al, Fe, etc.) tends to lead one to fairly simple flowsheets. Ignoring trace elements, and the various halide species generated, will lead process engineers down a development path that is sure to cause material handling issues. Researchers at Colorado School of Mines are modeling the complex chemistry that exists within the body of e-waste?comprising 39 of the known elements. An understanding of the systems thermodynamic behavior will result in the development of a more robust, long-term process for the recovery of valuable materials from the e-waste stream.

Jan 1, 2005