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By G. Robert Guillet

Nepheline syenite is a light-colored feldspathic rock that is used primarily as an addition to the glass batch. It is also used in ceramics and as an industrial filler. Composed essentially of the soda and potash feldspars and nepheline, nepheline syenite contributes needed alkalis and alumina to the glass composition. And because it contains a higher proportion of these oxides per unit weight, it is a formidable competitor for feldspar in northeastern North America and parts of western Europe. Nepheline-bearing rocks are not uncommon on a world scale, but few are able to be beneficiated to a composition sufficiently low in iron to be used in the making of glass. Nepheline can only form in an environment deficient in silica. Hence free silica, as quartz, is always absent in the primary mineral assemblage. Biotite, hornblende and magnetite are usually present as minor accessory minerals, and zircon, garnet, muscovite, and apatite may be present as trace minerals. Nepheline syenite is produced for glass, ceramics, and filler markets by Unimin Canada Limited at Blue Mountain, in south- eastern Ontario. Unimin acquired the former Indusmin and IMC properties from Falconbridge Ltd. in 1990. Elkem Nefelin AIS commenced production of similar products from Stjernoy Island in northern Norway in 1961. Unimin acquired this company in 1992. Nepheline has also been a byproduct of apatite mining on the Kola Peninsula for many years, and in 1951 the production of alumina from nepheline was commenced in a plant near St. Petersburg (Leningrad). There are now four plants in the Russian Republic, two smaller ones based on nepheline tailings from apatite mining and two larger and more recent plants in central Siberia using other nepheline resources. All four of these plants are integrated complexes that produce alumina for the subsequent production of aluminum metal, sodium and potassium carbonates, and portland cement. Roofing granules are produced by the 3M Company from a nepheline rock in Arkansas. In 1980 and 1989, trial shipments of nepheline syenite were recorded from new sources in Brazil and western Turkey respectively. Recent interest is also recorded for deposits in China, Saudi Arabia, and British Columbia.

Jan 1, 1994

By Russell L. Cook

Stringent environmental regulations, which have limited the use of sludge ponds, coupled with the economic incentive to clean more 'coal or to add fine coal cleaning additions to existing preparation plants have increased the use of static thickeners in preparation plants. The Lamella Gravity Settler, sometimes de signated Lamella Thickener, is a shallow depth sedimentation device which has been applied in a variety of industrial process and wastewater control projects in place of the conventional raked thickeners. This paper presents the theory and design of the La-mella Thickener, as well as describing the operating results from several full scale installations in a variety of Appalachian preparation plants.

Jan 1, 1977

By Gary MacDonald

What is the primary function of an impact assessment? Many people at the International Association of Impact Assessment?s (IAIA) annual conference said that it is time to return to the fundamentals and consider the underlying drivers of impact assessments ? human health, safety and security. This fall, managers struggling with those fundamentals will receive extra support when a new course focusing on health and socially responsible security is launched online and in British Columbia, Canada, home to many of the world?s junior miners. Now in its 33rd year, the IAIA conference recently held in Calgary, Canada, typically brings together a range of professionals who work in the impact assessment field, including academics, as well as people conducting applied disciplines, such as social and environmental performance management. It is a chance for people grappling with how to assess impacts from projects (for example, dams, mining and other extractive projects), to compare notes and to talk about developments in how to measure, track and report on them. The comments about returning to fundamentals rose as participants talked about the ongoing and increasingly recognized divergence between three main impact assessment streams: environmental, social and health (EIA, SIA and HIA, respectively). Discussions in sessions and in the corridors included calls for streamlining, for integration, for improvement and sharing of practice ? particularly in the HIA stream, where those deeply engaged in the health discipline questioned how HIAs and their intended outcome of protecting human health can be better integrated into the EIAs or SIAs that dominate the impact assessment realm. EIAs and SIAs have become the main tool, particularly from a permitting perspective for large-scale mines, but seem to leave projects with little real information about what they need to do. Human health is not the only concern re-emerging. Although not reflected at the conference, there appears to be an emerging understanding of the need to link the determinants of health with socially responsible security practices. Companies conducting independent social performance assessments for international financial institutions based on the International Finance Corporation?s Environmental and Social Performance Standards increasingly wrestle with both community health and security issues as extractive companies encounter challenging social environments around the world. Once again, the intended outcome is to better protect human health, including avoiding health impacts from conflict, abuses and violence.

Aug 1, 2013

By Hakan Uyguçgil, Beril Bayraktar, Adnan Konuk

In mining, which is one of the industries with the highest risk of occupational accidents, a primary goal is to enhance safety through the thorough investigation of accidents using reliable methodologies. In this research, the data from 13,653 accidents reported in the Karadon Hard Coal Enterprise between 2000 and 2011 were analyzed and compared using the life-table and Kaplan-Meier methods. Accident records were classified and analyzed into four categories: environment-related, equipment-related, person-related and other accidents. Findings in terms of survival time indicate that environmentrelated and person-related accidents had the highest risk in Karadon, with equipment-related accidents having the lowest. This study established the reliability of using survival analysis methods to investigate occupational accidents in the mining sector. Given that environment-related and person-related accidents occur in a relatively short period, such as one year after starting work, it is recommended that research be done to improve workplace and occupational safety measures and broaden the training given to miners. Additionally, it is determined that increasing the use of automation and mechanization in underground coal mines, combined with developing a thorough equipment safety training program to raise awareness of the danger, can help prevent person-related occupational accidents caused by the interaction between equipment.

Feb 1, 2024

By F. D. Wang

This paper presents an innovative mining method with the application of the water jet. The basic principle of this mining method is to mine a thin panel slice with a water jet system and to allow the roof to deflect elastically and subsequently to be supported by the coal floor without artificial roof support. Through the sequential mining of layers from top to bottom, the entire seam is extracted and the roof rests upon the mine floor. The advantages of this method are that the safety of underground operation can be greatly increased and the surface overburden disturbance will be markedly reduced. . An economic evaluation of such a system is presented for the total cost estimated per ton of coal mined at the face. This evaluation is then compared to that of a continuous mining section utilizing a room and pillar mining method.

Jan 1, 1991

By Brian Young, Ben Pantony

Interferometric Synthetic Aperture Radar (InSAR) has played an integral role in many large scale tunneling projects globally. Until recently, it has been regarded as a complementary monitoring tool. On the Los Angeles Metro Purple Line Phase 1, InSAR was proposed as a primary means to replace weekly and bi-weekly surface monitoring requirements on surrounding critical infrastructure. This paper will summarize the statistical analysis approach engaged in order to compare and contrast a year of historical InSAR data to known geodetic survey data, in order to utilize InSAR as an operational monitoring tool on this project.

Jun 13, 2021

By X. Y. Yu, X. A. Wei, A. Zeng

"The flotation behaviors of diaspore and three kinds of silicate minerals - kaolinite, illite and pyrophyllite - using an organosilicon cationic surfactant as collector were investigated as functions of reagent concentration and pulp pH. The results show that the organosilicon cationic collector QAS122 is a suitable collector for the flotation of aluminosilicate minerals but has weak collecting ability with regard to diaspore, enabling the flotation separation of diaspore from silicate minerals using QAS122 as collector. The flotation of a bauxite ore was then studied in detail. Finally, a reverse flotation separation process was used to process a low-grade bauxite ore. It was concluded that use of the organosilicon cationic collector is effective. A concentrate with aluminum oxide (Al2O3) to silicon dioxide (SiO2) mass ratio, or A/S, of 9.67 was obtained from natural bauxite ore with A/S of 6.07 at pH of around 11. The Al2O3 recovery rate was 81.72 percent. IntroductionChina has abundant bauxite ore resources, but more than 98 percent of the bauxite ores are the diasporic type, with the characteristics of complex mineral composition, low aluminum oxide (Al2O3) to silicon dioxide (SiO2) mass ratio, or A/S, and difficulty of processing. The gangue minerals in bauxite ores are mainly kaolinite, pyrophyllite and illite, containing titanium and iron impurities (Zong et al., 2008). It is known that high-grade bauxite ore, with A/S greater than 8, can be processed directly by the Bayer process (Papanastassiou et al., 2002; Ma et al., 1996). However, Chinese diasporic ores have been processed mainly by the sintering process, which is environmentally damaging and energy intensive. Increasing the A/S of the diasporic ores using a flotation method is needed (Xia et al., 2010).Froth flotation is one of the most widely used processes to concentrate valuable minerals in beneficiation ores. It is particularly useful for separating finely ground ores from their associated gangue minerals. For diasporic bauxite ores, flotation is applied to obtain high-quality material for the Bayer process by increasing the A/S. Direct flotation has been shown to be an efficient method for the desilicating of diasporic bauxite ore (Wang et al., 2004; Xu et al., 2004), but reverse flotation has more advantages for this purpose, including less collector consumption, less foaming product and less effect on metallurgy (Liu et al., 2007; Hu et al., 2003; Hu, 2003; Luo et al., 2001)."

Jan 1, 2015

By Philip L. LeHoux

In recent years, much work has been done to explain the nature of the gold-carbon adsorption mechanism. The benefits of a sound theoretical basis has the obvious application to gold adsorption and elution industrial processes. Unfortunately, the lack of a clear agreement on the mechanism has provided no clear direction towards process innovation and optimization. Jones' (1989) work has gone a long way towards clarifying the specie of gold adsorbed (and thus the chemistry required to remove it). Since the development of hot caustic and cyanide elution, the kinetics have been accelerated by the application of pressure to increase elution temperatures beyond the boiling point at atmospheric pressure. However, the traditional reagent content of 15 g/L NaOH and 5-10g/L NaCN has remained largely unchanged. This is in spite of work that has shown that the presence of cyanide is not required for the elution process to take place (Adams, 1986; Adams; 1989; Jones, 1989). Adams (1989) has also compared NaOH elution rates with and without cyanide. He found improvement with the use of cyanide and a synergistic effect with the use of both. Others have found no difference in overall extraction (Jones, 1989

Jan 1, 1990

By Zhiyuan Shen, Dan Zhao

The abstract discusses the importance of reliable mine monitoring systems for preventing accidents. It focuses on diagnosing ventilation system failures caused by roadway faults that alter airflow resistance. The paper proposes using an improved Support Vector Machine (SVM) method to identify the fault location based on changes in air volume detected by wind speed sensors. The approach involves building a sensitivity 0-1 matrix and establishing a roadway fault scope library. The improved SVM method is tested on the Daming coal mine, demonstrating its effectiveness in diagnosing fault locations, reducing training time, and improving accuracy compared to traditional SVM.

Apr 5, 2022

By D. B. Buddecke

Powell Bend Mine, located in Bastrop County, Texas, is owned by the Lower Colorado River Authority (LCRA). The mine is operated under contract by the Powell Bend Mining Company (PBHC), an affiliate of Pittsburg and Midway Coal Mining Co., and produces 210,000 tons of 6500 BTU/LB lignite per year for LCRA's Fayette Power Project near La Grange, Texas. PBHC operates the surface strip mine one shift per day, five days per week with a total of nine employees; six operations/maintenance and three office/supervision. The mine's productivity in 1988 averaged 100.3 tons per manshift using an l8-cubic yard dragline to uncover the lignite. Delivered cost to LCRA, F.O.B. mine, is $6.11 per ton, which includes water control and final reclamation.

Jan 1, 1990

By M. A. Reyes, L. Yan

Heat and humidity buildup withn refuge alternatives (RAs) may expose occupants to physiological hazards such as heat stress. The Mine Safety and Health Administration (MSHA) regulations require RAs in underground coal mines to provide a lifesustaining environment for miners trapped underground when escape is impossible. RAs are required to sustain life for 96 h while maintaining an apparent temperature (AT) below 95 °F (35 °C). The National Institute for Occupational Safety and Health (NIOSH) tested a 10-person tent-type RA, a 23-person tent-type RA, and a 6-person metal-type RA in its underground coal mine facilities to investigate the thermal environment over a 96-h period. The test results showed that mine air and mine strata temperatures surrounding an RA occupied by simulated miners (SMs) increased over the 96-h test period. The test results suggest that RA manufacturers should consider this increase in temperatures when calculating and evaluating RA components during surface and laboratory tests. The findings can equip stakeholders with additional considerations for calculating the interior heat and humidity temperature profiles for occupied RAs not tested in situ.

By C. W. Schultz

The Alabama tar sands of the Hartselle Sandstone formation present a more difficult problem in primary extraction than do the Athabasca tar sands. In contrast to the Athabasca tar sands, the Alabama tar sands are "oil wetted" and the contained tar, or bitumen, is of much higher viscosity. A physical beneficiation scheme was developed in which clean sand from an external source was used as a scrubbing medium. High intensity scrubbing liberated the tars which are readily recovered by froth flotation. Locked cycle tests have shown that, after the use of an initial ration of clean sand, the system produced enough new clean sand to be self sustaining.

Jan 1, 1992

By H. M. Ray

The discovery of the New Lead Belt in the mid-'50s began a search for mill design criteria that is continuously updated. The opportunity to design, construct, and operate four new mills in the span of 20 years provided fertile areas for new concepts. The central theme for design parameters encompassed simplicity, functional, and economic consideration. Ore characteristics for each plant remained relatively constant, providing stable criteria for grinding circuits. Bond index nominally 10-12. Flotation circuit parameters were based upon power application with 10-20% excess capacity built-in to protect recovery. Newer equipment exhibits greater power application efficiency lowering horsepower requirements per ton. Instrumentation was installed to stabilize circuits, protect equipment, and improve products. With ever increasing requirements of higher quality products, environmental considerations, and operating cost pressures, the upgrading of operating procedures is in a constant state of flux. Installation of more efficient equipment, chemical processing, or any other technique would be considered as feasible. Current practice is for St. Joe to design and engineer in-house its own plant design. The exception being detailing of structural steel. It is felt that familiarity with past design criteria serves as a valuable foundation to incorporate changes. Also, direct contact with operator provides specific data, and feedback for constructive criticism that is utilized for defining and correcting problems. The results are in reality an operator's plant with the benefit of advancing technology that meets the demands for improved products without sacrificing the economies of throughput or recovery.

Jan 1, 1977

By W. Bosmans

The European Commission published its Communication of the Thematic Strategy on the sustainable use of natural resources ("Resource Strategy") on 21 December 2005. The Resource Strategy aims at reducing environmental impacts associated with resource use - called decoupling - in a growing European economy and worldwide. The impacts of unsustainable resource use include e.g. climate change due to fossil fuel use, land use and environmental degradation due to mineral extraction and processing, or overexploitation of soil and fish stocks. To decouple environmental impacts from economic growth, a life-cycle approach is adopted. It means that the environmental impacts are taking into account at each stage of the life cycle of a resource, avoiding that negative impacts are shifted to other environmental media, to other stages of the life cycle, or to other countries. Key to achieving decoupling are three factors: - More value - creating more value while using fewer resources (?resource productivity?); - Less impact - reducing overall environmental impact per unit of resources used (through ?cleaner? technologies and consumption pat-terns); - Better alternatives - substituting currently used resources with better alternatives. The paper focuses on the implementation actions of the Resource Strategy in particular related to the minerals industry: 1. The Data Centre on natural resources; 2. Indicators to measure progress; 3. The involvement of economic sectors to take concrete actions; 4. EU Member States involvement, focusing on resource uses with the most significant impacts; 5. The International Panel on the sustainable use of natural resources, set up together with UNEP. With its 25 years time horizon and its wide approach the Resource Strategy will have a co-ordinating function to ensure enhanced coherence and efficiency. The challenge will be to integrate this approach into all policies and decision-making.

Jan 1, 2007

By Sotiris Psomas, Colin M. Eddie

"Steel Fibre Reinforced Concrete (SFRC) Segmental Tunnel Linings have successfully been used for over 20 years in the UK and have been adopted in a number of high profile projects such as High Speed 1, Crossrail, Thames Tideway, as well as High Speed 2. Tunnel linings and especially SFRC design are not covered in the Eurocodes. This shortage of SFRC tunnel design rules seems to be partially addressed by several international publications. However, in the UK, the ‘design-assisted by testing’ (DAT) approach has also been adopted. The Paper discusses the UK’s best design practice and focuses on the DAT methodology as applied in the case of the 6.9km (4.3miles), 7.8m (25.6 feet) ID Lining for the £635million Lee Tunnel Project. The design approach, the full scale testing at the Building Research Establishment (BRE), and the construction innovations are presented. This experience will be transferred to the £4billion Thames Tideway Tunnel.INTRODUCTIONSteel Fibre Reinforced Concrete (SFRC) has been used for Tunnel segments for more than 20 years. The first application of SFRC in the UK was for the Heathrow Baggage tunnel (1994). Since then significant size tunnels have been designed and constructed, such as the Jubilee Line (1999) High Speed 1 (CTRL, 2006), Crossrail (2014), Lee Tunnel (2014) and the scheduled 25km Thames Tideway (‘Super Sewer’) and High Speed 2 rail tunnels. However one the main obstacles in achieving streamlined design and improving efficiency are the lack of appropriate design guidelines for SFRC tunnel segments. This issue will – to some extent – be addressed by a number of current documents on tunnel FRC design either being produced by BSi (PAS8810, expected 2016), ACI (544.R) and ITAtech (Design Guideline PCFRC, 2015) in an effort to advance the design of SFRC and take into consideration the recent developments in Steel and Macro-Synthetic FRC technology."

Jan 1, 2016

By H. Huang, R. N. Gow

"In Part I, Gibbs’ phase rule was applied to mass-balanced EH-pH diagrams for the Cu-As-S-H2O system. The diagrams were generated using the stoichiometry of enargite as a basis. In this study, the calculations were expanded to cover the stoichiometries of three other Cu-As-S minerals – tennantite, sinnerite and lautite – and compared with enargite. Stability regions within the resulting EH-pH diagrams were found to change with stoichiometry such that a particular mineral would predominate if its stoichiometry was used in the calculation. Solution speciation was also found to vary, with thioarsenate being the best example. This stoichiometric effect helps to explain results reported in the literature and would be difficult to realize if it were not for mass-balanced calculations. IntroductionA comprehensive thermodynamic review has been conducted on the aqueous copper-arsenic-sulfur (Cu- As-S) system (Gow et al., 2014, 2015a, 2016b; Gow, Huang and Young, 2016c). Data on the free energies of more than 100 species were collected from various authors, and thermodynamic databases collated to produce mass-balanced EH-pH diagrams using the thermodynamic equilibrium calculation software STABCAL (Huang, 2014). The full database is listed and discussed in Gow et al. (2015a). Diagrams were generated for enargite and confirmed with Raman spectroscopy using bulk mineral electrodes in order to identify reactions spectroelectrochemically. Theoretical calculations agreed well with the experimental results under alkaline conditions (Gow et al., 2015a), acid conditions (Gow et al., 2014) and alkaline sulfide leaching conditions (Gow et al., 2015b).In the present study, additional mass-balanced EH-pH diagrams were generated by changing the Cu-As-S stoichiometry from enargite (Cu3AsS4) to tennantite (Cu12As4S13), sinnerite (Cu6As4S9) and lautite (CuAsS). Regions for the thermodynamically stable species were shown to change with the four different mineral compositions. Potential leach conditions, both for co-dissolution and selective dissolution techniques, were examined for differences in predominant species according to changing copper-to-arsenic ratios, sulfur compositions and sulfur oxidation states."

Jan 1, 2016

By G. J. Goldberg

Through the early 1980's, 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 of total station systems and their ability to meet the surveying requirements of Bingham Canyon culminated in the purchase of a total station system as the mine re-opened in 1986. This paper presents the procedure for evaluating, implementing and using the total station survey system at Bingham Canyon.

Jan 1, 1990

By Arthur R. Still, Paul A. Bailly

5.1-PURPOSE, PROCEDURE, METHODS, MANAGEMENT Exploration can be technologically defined, with regard to the discovery of new mineral deposits, as all the activities and evaluations necessary before an intelligent decision can be made establishing size, initial flowsheet and annual output of new extractive operations. The purpose of mineral exploration is the discovery and acquisition of new mineral deposits amenable to economic extractive operations now or in the future. A prime objective of mineral exploration, however, is to find and acquire a maximum number of such mineral deposits at a minimum cost and within a minimum time. Immediately upon the heels of a successful ''exploration" discovery follow activities called, first, development, then operation. Under U.S. Internal Revenue Code regulations (Secs. 1.615.1 and 1.616.1) in effect at the time of this writing, which state that the "development stage" has been reached when "deposits of ore or other minerals are shown to exist in sufficient quantity and quality to reasonably justify commercial exploitation by the taxpayer," exploration in the technological sense may well continue after a mineral property has entered the "development stage" as defined for tax purposes. In many instances continued exploration, after reaching the tax defined "development stage," has disclosed additional reserves which justify a much larger, more efficient and more profitable operation than that which would constitute the minimum feasible. Even after a mine goes into production, continued ore search generally will increase the reserves, either justifying expansions in plant capacity or prolonging the life of the operation, but this work (actually "exploration") is normally considered, for bookkeeping and tax purposes, a part of mine development. Each exploration entity defines its own objectives in terms of acceptable mini- mum rate of return on investment for any deposit found and retained, and in terms of which commodities, and markets, are to be involved. For these reasons, exploration programs, and aims, will vary over a wide range, although all have the common objective of endeavouring to create new profit centers for the future. 5.1.2-EXPLORATION METHODS Exploration has evolved in the past several decades into a highly sophisticated and expensive endeavor in which large corporate entities, or subsidaries, normally are directed and staffed by highly trained exploration specialists. In some instances consultants, with expertise in a given field, are utilized to the benefit of such corporate groups. The "grasshopper" approach to exploration-searching only for outcropping minerals and/or investigating only mineral prospects offered by the discoverers of such outcrops has given us most of the past and present mines in the US., but this method is rapidly approaching the point of diminishing returns in areas that have been thoroughly prospected for currently marketable commodities. With

Jan 1, 1973

By Wendell E. Bearce

At the, Crescent Valley Mine of the Hanna Coal Company, several 10,000 ton unit trains of 41" x 0 strip coal are loaded per week during the lake season. This is accomplished without the use of any accumulation of prepared coal. A large raw coal pile is built up during the winter months adjacent to two truck dump bins. This is added to whenever trucks are coming in from the pits and trains are not being loaded. During the loading of trains, trucks from several pits dump into the truck hoppers and coal is also dozed in from the pile. At a rate up to 3200 tons per hour this coal is screened, the plus 6" hand picked, the plus 4" crushed, and' all weighed and sampled as it goes directly to railroad cars being handled on two tracks by car retarders. With such an arrangement it is possible to exercise some control over coal quality, if it can be assessed rapidly. For instance, if the moisture rises to a level where it seems probable the BTU per pound will be reduced to the point where the contract calls for penalties, the trucks from, the wettest pit may be stopped, more or less coal may be moved in from the stockpile, or other measures taken to assure that the average BTU of the trainload will be satisfactory.

Jan 1, 1967

By Felicia F. Peng

A laboratory fixed bed reactor was used in a study of generating clean thermal energy from coal fine refuse-limestone agglomerates. The major operation variables, including Ca/S mole ratio, agglomerate size, air flow rate and temperature, which affect the rate of sulfur fixation and combustible material utilization, have been examined. The test results show that 70 percent or more of sulfur fixation and 100% of combustible material utilization can be achieved depending upon sorbent, agglomeration, and combustion conditions. The coal fine refuse limestone pellet combustion process (CLC process) requires a simple flowsheet to convert coal fine refuse as a clean solid fuel, while meeting the strict air quality standards for SO2 emissions into the atmosphere. The CLC process is an attractive method to clean up coal slurry impoundments to protect our environment.

Jan 1, 1984