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Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to be geochemically, spatially, and temporally variable, which presents challenges in collecting both exploration and baseline water-quality samples. Because short-term (daily) variations can complicate long-term trends, it is important to consider recent findings concerning geochemical variability of stream-water constituents at short-term timescales in designing sampling plans. Also, adequate water-quality information is key to forecasting potential ecological impacts from mining. Therefore, it is useful to collect baseline water samples adequate for geochemical and toxicological modeling. This requires complete chemical analyses of dissolved constituents that include major and minor chemical elements as well as physicochemical properties (including pH, specific conductance, dissolved oxygen) and dissolved organic carbon. Applying chemical-equilibrium and appropriate toxicological models to water-quality information leads to an understanding of the speciation, transport, sequestration, bioavailability, and aquatic toxicity of potential contaminants. Insights gained from geochemical and toxicological modeling of water-quality data can be used to design appropriate mitigation and for economic planning for future mining activities.

Jan 1, 2011

By M. Moagabo

CO2 emissions from carbonate laden reclaimed mine spoil has been shown to pose a hazard to residents in homes built on or adjacent to such land. The objective of this project was to develop a soil CO2 flux survey protocol for assessing reclaimed mine land. The research involved CO2 chamber accumulation flux surveys; stable carbon isotope ratio analysis; statistical hypothesis testing to examine correlation between CO2 flux and soil temperature and moisture as well as spatial dependence; and geostatistics to map CO2 and delineate high flux zones. Soil temperature was observed to have a positive correlation with fluxes while soil moisture was observed to be negatively correlated. Spatial dependence of CO2 fluxes on reclaimed mine land was observed on one of the two study sites. The research suggests that macro-porosity and gas permeability may be important factors that explain CO2 migration in mine spoil. A flux survey protocol has been developed, based on these results, for reclaimed mine lands. The work demonstrates the capability of geostatistical methods to delineate high flux fields. Further research will be required to determine suitable thresholds for such analysis.

Jan 1, 2012

By E. A. Metz

Perfect combustion in an engine would produce only water vapor, carbon dioxide and nitrogen as by-products; however, complete combustion is never achieved. As a mobile power plant, the diesel engine is relatively inefficient in terms of energy produced from the energy potential of the fuel. The diesel is not a perfect engine. The fuel burned can undergo a very large number of reactions in the combustion chamber. It only stands to reason that a large number of compounds are contained in the exhaust, actually, thousands of chemicals. The exhaust can be broadly divided into a gaseous phase and a particulate phase. Each phase is made up of organic and inorganic compounds. The vapor phase contains carbon monoxide, sulfur dioxide, various oxides of nitrogen and many hydrocarbons. The particulate phase contains clusters of respirable inorganic particles made mostly of carbon. This paper will address the health hazards, as we know them today, of the major components of the particulate phase in the exhaust of diesel engines. It will briefly examine the operational factors of the diesel engine as it applies to particulate emissions. Longitudinal studies of occupationally exposed miners are needed with documentation of levels of exposure before a chronic effect of exposure can be determined. At this time, it is not possible to conclude from human studies the level of diesel exhaust exposure that results in the observed lung cancer risk.

Jan 1, 2001

By C. R. Landis

The Wyoming bentonite industry continued its run of stable, if not strong, growth in its complex markets. Growth at the macroscale was fueled by a strong domestic economy, the weakening of the U.S. dollar in the global market and strong worldwide global demand. Challenges to the benchmark of the industry were rapid and saw ongoing increases in raw material costs(pallets, bags and additives), higher energy costs and higher overall transportation costs for all modes of movement. Exports continued to be assisted by dollar depreciation (5 percent to 10 percent) from January 2004to January 2005. This depreciation followed the significant weakening of 2003. And it was most favorable during the pullback in fuel and shipping rates in the second half of the year.

Jan 1, 2005

By Michelle Stokes, Alexandra Miller, Campbell McKenzie

"The ancestral Ringarooma River in northeast Tasmania has transported alluvial tin and other heavy minerals from their onshore source of stanniferous Devonian granites downstream into what is now Ringarooma Bay. Previous exploration work has demonstrated the presence of potentially economic tin mineralisation within the palaeochannels and terraces associated with the submerged river.The offshore tin resource lies directly on the seabed or with less than 2 m of overburden, and within 5 - 50 m water depths in the wider bay area. The main river channel continues offshore for at least 13 km, with high tin grades found within the palaeochannel but also dispersed across the sea floor as a sheet wash, a result of Quaternary sea level change reworking the placer deposits. This drowned portion of the coastal plain contains a continuation of rich tin leads as low gradient anastomosing channels, and has been delineated by marine seismic and drilling activity since the 1960s. Tin grades in the Tertiary and Quaternary alluvial profiles vary from 50 - 300 g/m3, with the highest concentrations in the coarser basal horizons. A previous offshore explorer estimated a resource of 194 Mm3 at 150 - 250 g/m3.Kenex Ltd created 3D models of the paleochannels and the mineralisation with the aim of better constraining the resource estimate and identifying additional depositional areas. The modelling was undertaken with the input of geophysical data, bathymetry and geochemical sampling of the seabed surface and from historic offshore drill holes. A prospectivity model covering Ringarooma Bay was produced to target tin-bearing gravels. Predictive maps were created to represent various features of the offshore mineral system, including assessing gradient changes in palaeochannels and their sinuosity. The model identifies areas with higher potential for alluvial tin mineralisation and will be used to focus the exploration programme over tenements currently held by Kenex Ltd."

Sep 1, 2014

By Wijnand Dalmijn, Hans de Ruiter

Experience over the past eight years has proven that partnership and cooperation in mineral engineering education is essential to maintain programs in this field. At this moment the joint European Mineral Masters Engineering Course (EMMEC) has three programs in the areas of mining, minerals engineering and geotechnical/environmental engineering, offered by combinations of nine universities in seven European countries. About 25 companies are associated with the universities in the Federation of European Mineral Programs (FEMP) which coordinates these activities. The EMMEC has applied for recognition under the newly launched EU “Erasmus Mundus” program in which the EU makes 280 million Euro available for bursaries for non-European students and scholars.

Jan 1, 2005

By N. Abdel-Khalek, A. Youssef

The tailings from beneficiation of Florida phosphate ore contain considerable phosphate values. These tailings are currently discharged into large disposal areas. More than three million tons of P2O5 are discarded with the phosphatic slimes (clays) in Florida each year. These phosphatic clays not only create one of the most difficult disposal problems in the mining industry, but also represent a tremendous loss of P2O5. As the quality and quantity of Florida’s phosphate reserves diminish, recovery of phosphate values from these wastes becomes more vital. This will also significantly lengthen the life of these important phosphate resources. Thus, it is the goal of this study is to recover more than 80% of the phosphate values in phosphatic clays. A systematic study to characterize samples taken from inactive disposal area has been conducted. The data suggest that natural segregation takes place in the settling pond. In other words, coarser particles settle closer to the feeding point of the pond. Flotation tests were conducted using the +325 mesh fraction of samples obtained from sites close to the feeding point (sample# A) and further from that point (sample# B) and (sample# C) which is even further away from the feeding point. The results show the following: Sample# A gives the highest grade and recovery, followed by that of # B and then of # C. There is a great potential to upgrade sample# A where concentrates of high grade (68.9-70.1 % BPL or 31.5- 32.1% P2O5) and recovery (~86.6-95.4 %) can be obtained under the investigated operating conditions (1.0 – 2.0 kg/ton sodium silicate and 1.5—3.0 kg/ton collector mixture of fatty acid and fuel oil). The mineralogical and chemical analysis of all samples is presented in this paper for comparison. Only in this paper, the flotation data of (site # A) are discussed below.

Jan 1, 2002

By N. M. Can

The effects of microwave treatment on the floatabilities and magnetic susceptibilities of some sulfide minerals, namely, pyrite, chalcopyrite, galena and sphalerite, were studied. Pure mineral samples were prepared in -425+212-µm, -212+106-µm and -106+38-µm size fractions. Microflotation and magnetic separation tests were carried out on the samples after microwave treatment at 600, 950 and 1,300 Watts for 5, 20, 60, 90, 120 and 240 seconds. The maximum temperature values of the samples were measured during the microwave treatment, and possible altera-tions on the mineral surfaces were determined by X-ray diffraction (XRD) analysis. The effects of microwave treatment are discussed based on the result of microflotation and magnetic separation tests. The results revealed that pyrite, chalcopyrite and galena were heated very quickly and that their surface temperatures reached ~700° to 900°C, while the temperature of sphalerite reached only ~130°C. The floatability of pyrite, chalcopyrite and galena were decreased when microwave energy and the duration of treatment were increased, owing to oxidation of the mineral surfaces caused by relatively high temperature. As expected, there was no change in the floatability of sphalerite. The magnetic properties of pyrite and chalcopyrite were improved by the increase in microwave energy and the duration of treatment to such an extent that 90% of the feed separated as magnetic product. But no change was observed in the magnetic properties of galena and sphalerite.

Jan 1, 2007

By S. Möllerherm

"The evaluation of data and information provided by the existing traditional indicators in sustainability assessments is most important. Therefore the Institute of Mining Engineering I from the RWTH Aachen University developed indicators and an assessment system for the mineral raw materials industry on 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 Geosciences and Natural Resources (Bundesanstalt für Geowissenschaften und Rohstoffe, BGR). In the course of the development of indicators for the raw materials industry quality indicators on different levels of the sustainability assessment procedure have been identified and developed. The following paper describes some of the results focussing on the development and integration of quality indicators into sustainability assessment systems."

Jan 1, 2005

By R. L. Andrew

The southwest Pacific has produced at least four of the world’s premier porphyry copper-gold deposits, and the current level of exploration is likely to produce even more. An appreciable amount of gold is being produced with this copper, with obvious economic advantages. Gold content, in addition to their large size, makes the southwest Pacific’s porphyrycopper-gold deposits very attractive exploration targets. The recognition of telescoping and overprinting of porphyry systems has produced a greater awareness of the likely surface expressions, in particular the significance of advanced argillic lithocaps in porphyry exploration. The recognition of the spatial and genetic association of porphyry copper and epithermal gold systems (Sillitoe, 1972), as in other parts of the world, has had important implications for exploration in the Asia Pacific region.

Jan 1, 1995

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 M. A. Meyer

Underground mining accidents in the USA in recent times have prompted the Mine Safety and Health Administration (MSHA) to review emergency and tracking systems for underground mines. Several communication and tracking systems are available on the market and various systems have been installed in mines around the world. In addition, MSHA?s standard on Diesel Particulate Matter (DPM) requires mines to comply with the final PEL of 160µg/m3 by May 20, 2008. Barrick Goldstrike Mines Inc., Underground Division, has been in operation since 1995 and an extensive control and monitoring network, and a leaky feeder voice network is in place. Enhancements to the communication and control system are currently being implemented to include a PED emergency notification system, wireless LAN with tracking of personnel and equipment in the mine, and a ventilation control system that will use the tracking information and ventilation data to automate much of the mine ventilation system. Expected benefits from such a system would be enhanced communication with miners, emergency notification, location of miners and equipment, energy savings, improved ventilation control, and improved atmospheric conditions in the mine including reduction of diesel particulate matter (DPM).

Jan 1, 2009

By M. Martins

This work presents and discusses the influence of the surface tension (gLV) of methanol/water mixtures on the flotation response of apatite versus gangue minerals conditioned with flotation reagents (75 g/t cornstarch and 100 g/t Berol 867) at pH 10.6. Berol 867 is a collector composed of sodium alkyl sarcosinate plus nonionic surfactant. The highest Schulz efficiency of separation (recovery of apatite minus recovery of gangue) was achieved at ?51.0 mN/m. The critical surface tension of wettability (gC) of apatite was found to occur at 34.7 mN/m when determined by means of gamma flotation experiments, and it was 33.9 mN/m when determined by Zisman?s approach.

Jan 1, 2009

By J. D. Potts

Dust surveys were conducted at six underground coal mines to determine if deep-cutting practices expose face workers to higher levels of respirable dust. The surveyed mines were able to successfully mine deep cuts without significantly increasing the dust exposures of face workers. For exhausting face ventilation, field data indicate that scrubber airflow is the most important factor for controlling dust. Data collected for this study indicate that 20-mesh screens should be cleaned for every 40 ft of advance because 22% of the deep cuts surveyed for this study experienced a 20% to 35% decrease in scrubber airflow over the course of the cut. For blowing face ventilation, field data and past research indicate that dust control is aided by maintaining a proper curtain-to-scrubber airflow ratio of 1.0 (measured before scrubber activation) as well as a curtain setback distance that allows the miner operator to stand at the mouth of the curtain for the entire cut. Dust levels on the bolting faces did not appear to be affected by the longer cycles associated with deep-cut mining when good ventilation practices were used.

Jan 1, 2011

Several industrial-scale HydroFloat separators have recently been installed at Mosaic?s South Fort Meade beneficiation plant for the purpose of improving phosphate recovery and throughput capacity. This technology was implemented after numerous laboratory, bench-scale and on-site, pilot-scale test campaigns. The results from this detailed test work provided sufficient justification for the complete retrofit of the existing coarse and ultra-coarse flotation cells. Data indicate that the metallurgical results obtained with the full-scale separators are consistent with that obtained during both the bench- and pilot-scale evaluations. The benefits, theory of operation and commissioning of the equipment are also discussed.

Jan 1, 2007

By G. Gaidajis, K. Angelakoglou

The development of a tool for assessing the environmental sustainability of mining facilities is described in this study. The tool is based on the analysis of basic components of the examined system, i.e., the quantities of the incoming materials and outgoing wastes, their hazardousness and scarcity, the utilization of water and energy resources, and the biodiversity. The developed tool provides both qualitative and quantitative assessment of the environmental performance of a mining facility in a broad time scales (past-present-future) and is easily applicable from non environmental experts. Moreover, relative software is developed to further support the application of the methodology. The implementation of the tool is expected to lead to an improved understanding of the environmental performance of a mining facility and more importantly identify the areas of significant environmental concern. However, based on feedback from industries, a number of shortcomings of the approach have been identified so far and are presented, indicating further actions for the advancement of the proposed tool.

Jan 1, 2011

By M. M. Poulton

Universities are not immune from the large number of retirements facing the mining industry. Department heads anticipate that we will need to replace all of the senior mining engineering faculty in the U.S. by 2020. Long term studies of Ph.D. completion times and success rates indicate that in Engineering disciplines in the U.S., the ten year completion rate is 65% at best and the four year completion rate is less than 8%. We do not have accurate data on completion rates and times for mining or metallurgical engineering Ph.D. students in the U.S. but students self-report their expected completion times are around 4 years. National data on doctoral students indicate that younger, full time students with sufficient financial support have a higher probability of success in completing their degrees in a timely manner. Students in Eastern U.S. mining engineering programs are on average 32 years old, 85% are full time, and the gap between support and cost of attendance is $5,000 per year. Students in Western U.S. programs are on average 38 years old, 78% are full time, and the financial gap is $8,483. Further, it appears that domestic graduate students are not very geographically mobile. The current demand for new faculty is higher in Western programs but the longer term retirements are higher in Eastern programs. While all Ph.D. students who responded to the 2010 survey indicated an interest in a faculty position at some point in their careers, very few were applying for the open positions. Over the past 35 years for which data could be obtained, the maximum number of Ph.D. students enrolled in mining engineering in the U.S. is 115 with a maximum of 27 degrees granted in one year. On average 89 students are enrolled in doctoral programs in mining engineering in the U.S. with average degree production of 15 Ph.D.s per year.

Jan 1, 2012

By Russel Delmar, Rick Everdell, Harry Charalambu, John Tait

Award of the Design/Build Agreement for construction of Ontario Power Generation’s (OPG’s) Niagara Tunnel Project was made after an intensive 8-month international procurement process. The 14.4-m diameter × 10.4-km long rock tunnel will divert 500 m3/s of water from the Niagara River to the Sir Adam Beck hydroelectric generating complex. The procurement process and Design/Build Agreement included features to address the owner’s requirements regarding risk allocation and cost and schedule certainty, while encouraging innovative ideas from the industry, both technically and commercially. The process included an international expression of interest and prequalification, followed by an invitation for design/build proposals to qualified proponents, and comprehensive proposal evaluations and negotiations with several respondent proponents. An honorarium was provided to the unsuccessful participants in the proposal stage. The resultant negotiated Design/Build Agreement includes Owner’s Mandatory Requirements, negotiated contract terms and conditions, performanceincentive bonuses and liquidated damages for schedule and water delivery performance, a multistaged Geotechnical Baseline Report, joint risk management, references to preexisting community impact agreements and measures to reduce impact on tourism. It also addresses regulatory approvals and permits, an owner controlled insurance policy that required reference to the International Tunneling Insurance Group (ITIG) Code of Practice for Risk Management as a condition of coverage, site specific safety, security and environmental plans, formal team building, a dispute review board, and escrow documentation.

Jan 1, 2007

By I. Gombköto, G. Földing, G. Mucsi, B. Csoke, J. Faitli, B. Kovács

This paper summarizes the main achievements of our previous project entitled "Development of a technological system producing quality guaranteed fly-ash based binder". Furthermore, this study deals with the laboratory experience of lignite fly ash utilization for two different goals. On the one hand the fly ash was tested as a binder; on the other hand it was investigated as an underground mine backfill material. Considering the first goal, the utilization of a mixture of mechanically activated fly ash and lime for producing an independent binding composition has been assessed involving determination of relationship between the degree of activation of fly ash and the strength of the obtained concrete. The results confirmed that this hydraulic binder is suitable for construction of stabilization and capping layers or base layer. Regarding the backfilling application, this paper presents laboratory experiments, their results including settling tests, hydraulic permeability and strength measurements and dense slurry technology related results.

Jan 1, 2011

By E. A. Metz

Work related pulmonary diseases are in the top TEN causes of occupational disability and death in the United States. Likewise, it also ranks high inmost of the other industrial countries. It is difficult to know the true occurrence of occupational lung disease because of poor documentation. This is especially true when one examines workers’ compensation claims. Most frequently, silica and asbestos are paramount in our discussion of work related pulmonary disease. Little consideration is given to other “dust-related” diseases, irritant reactions, reactive airway responses, and hypersensitivity reactions. The major classification of occupational lung diseases will be discussed. This includes both acute and chronic disease that arises in the work place, especially, the mining industry. It’s more important to make an accurate evaluation and diagnosis for the prevention of disease among other workers.

Jan 1, 2000