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By Ben Roderds

The Waneta Expansion Project (WAX) is located near the existing Waneta Dam site at the confluence of the Pend d?Oreille and Columbia rivers, approximately 10 km (6.2 miles) south of Trail, BC, Canada. The WAX owners consist of a partnership between Fortis Inc., Columbia Basin Trust and the Columbia Power Corp. This design-build project was awarded to SNC-Lavalin in late 2010 and is expected to be operational in mid-2015. The WAX consists of a new 335-MW powerhouse, including two new Francis turbine units, each generating approximately 167 MW. The powerhouse is located downstream of the existing Waneta Dam, and will make use of excess water that would otherwise be spilled during the runoff season. Water will be funneled to the turbines through an intake structure and two 10.5- m (34.5-ft) diameter, concrete-lined Penstock Tunnels. A 10-km (6.2-mile) transmission line will connect the powerhouse to existing electrical grids. Redpath/FKCI Waneta Tunnelers (RFK) was subcontracted by the heavy civil contractor, the Aecon/SNC Lavalin (ASL) joint venture, to excavate the two penstock tunnels and install the cast-in-place concrete liner. RFK is a joint venture partnership between J.S. Redpath Ltd., an underground mine contractor located in North Bay, Ontario, and Frontier-Kemper Constructors ULC, a heavy civil tunneling contractor based in Nova Scotia, Canada. Since penstock tunnel excavation was planned using drill-and-blast methods with a significant grade of more than 17 percent, the combined experience of these two contractors was a perfect match.

Mar 1, 2014

By Thomas P. Meloy

Floating "fines" differs from floating "sands" because the fines have a much larger surface area compared to their mass. The forces that arise from this large specific surface the key to understanding the behavior and treatment of fine particles. Though the nature of these forces is not thoroughly understood, enough work has been done to give a qualitative picture of what is happening in a flotation cell. It is the purpose of this chapter to re-examine some of the more, recent theoretical work and-to indicate its importance.

Jan 1, 1962

By Rameshwar Sah, Basavaraja Maribasappanavar, Sangamesh Desai, G. Balachandran, Ravi Kant Sagar

The present research work deals with the effective utilization of hematite ore containing goethite, kaolinite and gibbsite losson- ignition (LOI) phases in pellet making without deteriorating product pellet properties by optimizing the induration cycle especially drying and preheating of pellets. Adequate drying and preheating of pellets before sintering is of prime importance to sustain the desired properties of pellets. Green pellets of + 8 to − 16 mm size were prepared in a laboratory disc pelletizer and indurated by varying drying and preheating temperatures in a laboratory Raising Hearth Furnace (RHF). Produced pellets were assessed for physical and metallurgical properties. Improvement in drying and preheating temperature simultaneously helped in mitigating fired pellets’ property deterioration. Drying at 300 °C and preheating at 750 °C helped in the maximum removal of matrix LOI from the pellets before firing and enabled the production of pellets of desired properties. Laboratory scale findings successfully implemented at existing 4.2 MTPA capacity pellet plant of JSW Steel Ltd. Vijayanagar and high LOI iron ores (IOs) utilised which resulted in reduction of average monthly pellet fines generation by ~2 wt. %.

Jun 4, 2022

By J. A. M. Cano

Pot Grate tests were carried out in the pilot plant at Samarco producing pellets containing SiO2 between 2.0% and 2.2% in a wide range of basicity to be used in blast furnace. These pellets were submitted to tests in Samarco's laboratory and another laboratory in Germany to evaluate the metallurgical properties. The pellets in the binary basicity range (CaO/SiO2) from 0,87 to 0,95 were those that presented the best results in the Pot Grate tests. Based on the results, these pellets are being routinely produced?on industrial-scale confirming the results observed in laboratory tests.?

Jan 1, 1994

By L. J. Hoover

The objective of this study was to assess the health and environmental impacts of fluidized-bed combustion (FBC) of coal, specifically as applied to baseload generation of electrical energy by utilities. The study* was a short-term effort that based its analyses on information derived from the experience of the group or quickly obtained from the literature. The approach was to compare Atmospheric Fluidized-Bed Combustion (AFBC) and Pressurized Fluidized-Bed Combustion (PFBC) with two current technologies: low-sulfur coal combustion (LSC) and flue gas desulfurization (FGD) used with high-sulfur coals. A wet-limestone process was selected as the FGD technology. The impacts compared involved not only health and environment but also sociology, resource use, and dollar cost. Conditions for comparison were centered around a nominal date of 1988, when initial operation of commercial AFBC plants may occur. The PFBC has a later introductory date, a nominal 1995 (its impacts relative to other competitive technologies now in the R&D stages were not compared.)

Jan 1, 1978

By D. Gatzemeier

The Jewett mine is a surface mine in central Texas, producing about 8,000,000 tons/year of lignite. The mine covers 46,000 acres of land. Approximately 430 people are employed by Northwestern Resources Company and through their efforts, the Jewett Mine is one of the most productive mining operations in the country. The Jewett Mine utilizes a unique structure of staff to convert Operations Research into plans which can be implemented at the "front line" level of the Operations Team. This planning not only makes the mine cost effective and efficient, but promotes creativity in mining, which promotes ongoing research to lower the cost of mining.

Jan 1, 1993

By John B. Goddard

In-situ leaching of uranium by aqueous ammonium carbonate containing oxygen or hydrogen peroxide as oxidant results in the partial dissolution of sulfides. While some of the sulfide sulfur is oxidized to sulfate, a considerable portion is oxidized only to thiosulfate and polythionates. Polythionates poison the anion exchange resin used to extract uranium. At the Palangana operation in southeast Texas, the trithionate ion (S3062-) was found by infrared spectrometry to be the major resin poison. Treatment of ion exchange feed solutions with hydrogen peroxide only resulted in partial conversion of reduced sulfur species to sulfate, and trithionate conversion was particularly slow. Poisoning of the resin also occurred from the ammonium chloride eluant, which built up trithionate because of recycling. This was essentially eliminated by chlorinating the eluant prior to yellow cake precipitation.

Jan 1, 1984

By Emily Rose

The concept of risk management is applied to multiple aspects of the mining lifecycle including safety, mine design, business plan—anything that affects getting the ore to the mill for production. However, risk management is not a topic that can readily be taught in universities. Many situations require knowledge gained from experience to know how this impacts current and future operations. Recent graduates, who must develop and apply decisions based on geotechnical monitoring, likely have not developed “operational experience” and may not be aware of options and typical applications. Thorough resources that explain different monitoring systems, and when and how to implement them, are available for geotechnical professionals. Accessibility to this information can often cause information overload, leaving one unsure of where to start, without knowing where to start. This paper is intended to serve as a high-level overview of development practices, levels of risk, and risk tolerance for entry-level geotechnical and mining professionals who do not come from a geotechnical background. Summarized detail on typical monitoring practices, types of instrumentation, and how to communicate what the data indicates to key stakeholders are provided.

Feb 22, 2026

By L. Yuan, J. Soles, W. Tang, R. Thomas

Lithium-ion battery pack fires pose great hazards to the safety and health of miners. A detailed experimental study has been conducted at the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) to investigate the effectiveness of different fire suppression systems on Li-ion battery pack fire extinguishment. Tests were conducted in a well-ventilated container. Two sizes of battery packs (12V, 24V) were heated by heater strips to trigger thermal runaway and fire. Water mist with different flow rates, ABC powder, type D dry chemical, and water mist with F500 additives were used as the fire suppression agents. Multiple thermocouples were installed on the battery packs to measure the temperature evolution during the tests. The results indicated that the water mist with F500 additives is the most effective suppressant among the agents tested. Dry chemicals, however, do quench the fire for a moment, but cannot prevent re-ignition of the battery since they do not provide enough cooling. The findings of this paper can be used to develop safer battery fire suppression techniques in mining environments.

Feb 1, 2023

By D. D. Runnells, G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two of the pit lakes, 26- and 55-m (85and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper pit lakes, 110- and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1998

By W. I. Enderlin, P. O. Jackson, J. A. Glissmeyer, K. B. Olsen

A reliable estimate of radon emissions to the environment from underground uranium mines was obtained through measurements of radon in ventilation air at 24 mines and from estimates of radon release from other mine sources. The total production of U308 from the mines sampled represents about 63% of the total U.S. production from underground mines (1978 statistics). Wide variation in the radon emission rate per unit of production was found from mine to mine. Using the total radon emitted and U308 produced by all mines sampled, an average of 26.7 Ci of radon was emitted per ton of U309 produced. The investigation includes a brief study of the sources of variation of the emission rates. A statistically significant relationship was found between the measured radon release rate and the cumulative ore production at several mines.

Jan 1, 1981

By Jamal Rostami, Omid Frough, Wei Hu

Characterizing the abrasiveness of soil/rock and the allowable wear of hard-facing products in various conditions is a critical factor in selection of the best material for certain applications related to drilling and excavation in mining and construction industries. The Soil Abrasion Index test machine at Colorado School of Mines (CSM) is one of the recently developed unique systems capable of testing soil/crushed rock abrasion under various conditions, such as dry, wet, and saturated settings. It is also capable of testing the performance of various types of hard-facing materials in a given geo-material. This paper studies the wear properties of different hard-facing materials in various crushed rocks from a surface mining operation in the iron range region of the USA. The hard-facing materials include regular and hardened steels and six different specialized hard facings, based on chromium carbide. The soil/rock include a standard sand and two rock samples from the surface mine. Fourteen abrasion tests were conducted, where the weight loss of each hard-facing material was measured over timespans up to 1 h of testing. The results show the distinct performance differences between the steels with 17 HRC and 43 HRC hardness and the hard-facing products for this application. The results show the possibility to evaluate the abrasiveness of different rocks at a mine or construction site and the performance of various hard facings in similar working conditions. This is a practical solution for selection of the cutting tool or reinforcement of bucket lips and truck beds for comparison of relative wear life between different wear-resistant materials.

By Donald Towse

Geothermal heat might become an important fuel for several reasons: (1) To substitute for other scarce and critical fuels. (2) Because it may be less costly to the user than alternate fuels. (3) Because its production may be more profitable than production of other fuels. (4) Or for a number of other more or less non-economic reasons such as convenience or because of less environmental impact. In competition with conventional and other non-conventional fuels, geothermal heat must score well on one or more of those points. This study first considers projections of energy needs in several United States economic sectors and the technical possibility of geothermal heat substituting for other fuels in those sectors. Then, reported and projected costs of energy from geothermal heat are compared with costs of other fuels to show the relative costs of fuels in several economic sectors. Relative costs are reported from a sample of real and hypothetical geothermal projects. The actual cost of energy will vary with each application and the particular circumstances of each geographic location.

Jan 1, 1975

By Jeffrey A. Holcomb

INTRODUCTION The passage of Comprehensive Environmental Response Compensation and Liability Act (CERCLA/Superfund) as well as the Resource Conservation and Recovery Act (RCRA) and state laws, have placed added regulatory pressures on the mining industry. These laws which focus on the regulation of hazardous substances and wastes for the protection of the public health and welfare and the environment, present the potential for tremendous financial impacts and liabilities on existing mine operators and owners and/or potential mine operators/owners. This paper takes a brief look at these laws and presents an environmental audit procedure to identify environmental liabilities prior to mine land transactions. The environmental audit approach presented is an overview of the procedures that could be used to document, evaluate and inventory existing and/or potential environmental concerns. This audit procedure can be applied to developed or undeveloped properties and at active or inactive mining sites. REGULATORY OVERVIEW Mining environmental liabilities have been addressed in RCRA, Superfund, the Clean Air Act (CAA) and the Clean Water Act (CWA). Even though the U.S. Environmental Protection Agency (EPA) has determined that mining wastes will be treated as solid wastes under RCRA and not as hazardous wastes, these wastes could still bring about a great deal of financial liability under Superfund. The catch is if the mine wastes generated contain hazardous substances such as the heavy metals arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, zinc and others as well as cyanide. Thus, it is not only important for a mine operator/owner or a potential mine operator/owner to know if the mine wastes generated are hazardous, but it is important to know if the wastes contain hazardous substances. Following is a brief overview of RCRA and Superfund and their potential implications. RCRA RCRA, which provides the basis for the regulation of solid and hazardous wastes, is applicable to active mining and milling sites. Within RCRA the definition of a hazardous waste is provided. This definition applies to owners and operators of mining and milling sites if the operator has stored, disposed or treated hazardous wastes on-site. If this is the case and if strict process control and waste management activities are not adhered to, environmental liabilities may be associated with the site. Superfund The 1980 Superfund law can be applicable to inactive mining sites or to inactive sections of an active facility. The provisions of Superfund call for the regulation of hazardous wastes and hazardous sub- stances disposal and release not only by the existing owner, but also for any previous owner. This concept of joint and several liability means that one party, as among many, can be held totally responsible for the costs of hazardous waste cleanup (Haller, 1987). Furthermore, liabilities under Superfund have also been applied back to past acts; thus, several mining properties, active or inactive prior to the 1980 Superfund law, are at risk of being placed on the EPA's National Priority List (NPL) for cleanup. Last years amendments to Superfund, known as the Superfund Reauthorization Act of 1986 (SARA), provided some significant developments for the mining industry. The major requirement of the amendments as it pertains to owners or operators of mining sites is that the EPA must revise its present Hazard Ranking System (HRS). This is important be- cause in most cases the primary reason for several mining sites having been included on the NPL was due to the large volume of wastes generated. As is typical at most mining sites, large volumes of low toxicity wastes are generated and the current HRS model prejudices against this. It should be noted that this provision only applies to sites that are not already on the NPL or have not been proposed for inclusion on the list.

Jan 1, 1987

By R. J. Sweigard

Productive and beneficial use of reclaimed surface-mined land is a concern of industry, government, and the general public. An investigation was conducted of current mined-land planning practices to aid in the development of a procedure for evaluating postmining land use potentials. This investigation considered both the industry and public planning approach to mined-land planning and was based primarily upon three case studies conducted in various regions of the United States. The site planning process that was developed during the investigation is iterative in nature and has been designed specifically for the mining industry. It centers around preliminary studies and data collection, development of land use alternatives, and the evaluation of alternatives. Use of this process facilitates the evaluation of economic, environ- mental, and social impacts of postmining land use alternatives. In this paper, the process is presented along with a description of its development, application, and significance.

Jan 1, 1984

By Jr. Pickering

Kaolin is mined from extensive sedimentary formations in the eastern Amazon River Basin of Brazil. Production began about 25 years ago from 30 meter thick beds of ultra-fine particle clay of superior viscosity along the Jari River north of the Amazon. Operated by CADAM S.A., capacity now exceeds 750,000 tonnes per year ot high glossing paper coating kaolin product. South of the Amazon on the Capim River are two new operations: Para Pigmentos S.A. and Rio Capim Caulim S.A. The purity , and large coarse plate-shaped particles of these Capim kaolins support production of superior brightness and whiteness paper coating and filling grades. Annual capacities are reported to be 150,000 to 300,000 tonnes each, with expansions planned. Most of Amazon area kaolin production is shipped to western European, Asian, and North American markets.

Jan 1, 1999

By Matthew Preedy, Anthony Pooley, Mike Wongkaew, Dirk Bakker, Raghu Bhargava

Sound Transit’s ST3 program will add 62 miles of light rail to the Puget Sound area, including connections to the neighborhoods of West Seattle currently anticipated by 2031 and Ballard by 2036. These connections include considerations for both elevated and tunnel alternatives, as well as a new downtown tunnel for which different configurations are being considered with potentially very different construction logistics and risk profiles. This paper describes the latest developments in the ongoing evaluation process that will inform the consideration of different tunnel and station construction methods, technical and operational challenges and contracting methodologies, including construction of deep stations in dense urban environments.

Jun 13, 2021

By Junnan Chen, Hongwei Zhang, Wei Wang, Feng Xie

Thiosulfate is a green gold leaching agent that shows great potential to replace the highly toxic cyanide. Ammonia is traditionally used as the copper ligand in thiosulfate solutions to reduce the reactivity of copper ions towards thiosulfate, but it is a toxic reagent. As a result, efforts to replace ammonia with another complexing agent have received increasing attention. In this study, a novel alternative to ammonia is proposed to explore the potential use of the copper-malic acid-thiosulfate system. Experimental parameters include temperature, initial pH, copper, malic acid, and thiosulfate concentration. The feasibility of the copper-malic acid-thiosulfate system was discussed using Eh–pH and species distribution diagrams. Themodynamics analysis indicates that the mechanism of gold leaching in copper-malic acid-thiosulfate solution is mainly catalyzed by the Cu2( Mal)2H-2 2−/Cu(S2O3)3 5− redox couple. The capability of gold leaching in this system for processing the refractory gold concentrate is comparable to that of cyanidation and the traditional copper-ammonia-thiosulfate leaching processes. Thiosulfate consumption is greatly reduced in the presence of malate due to its strong chelating effect on the copper ions. Moreover, the copper-malic acid-thiosulfate system demonstrates a significant enhancement in leaching kinetics, making it a viable option for processing refractory gold concentrates.

Aug 1, 2023

By CADEN VITTI, Barbara J. Arnold

Mine tailings, the byproduct of mining and mineral processing, are increasingly mass produced as a result of increased demand for metals and minerals as well as the advancement in technology that allows for the exploitation of lower-grade ores. Lower grades can increase the volume of tailings that may contain new gangue minerals that should be evaluated for the presence of critical minerals and other valuable metals. The practice of reprocessing, while relatively new, is crucial to reducing environmental damages, obtaining valuable critical minerals from waste, and contributing to more sustainable repurposing and disposal methods. With the increase in tailings dam failures in recent years, there is a large motivating factor in remining and removing the potential hazard to benefit the safety of potentially impacted communities. In analyzing the perspectives of various domestic and international studies, this literature review will determine the feasibility of reprocessing and reutilizing mine tailings waste for a more sustainable future while exploring current practices that have benefitted ecosystems and communities.

Jan 1, 2022

By MARK J. VANARELLI

Estimating groundwater inflows in rock deep tunnels is critical to the safety of personnel constructing the tunnel and the cost of construction. This paper presents two case studies for estimating steady-state groundwater inflows into deep rock tunnels. The case studies included the Chattahoochee and Nancy Creek tunnels. In this paper, statistical methods were applied to packer test data obtained from exploratory borings during geotechnical site investigations. A semi-empirical procedure was utilized for estimating groundwater inflows into these deep rock tunnels. It is the most widely used method/procedure in the tunnel industry. The Chattahoochee and Nancy Creek tunnels are deep rock tunnels which exhibit radial flow conditions. For the radial flow condition, a statistical analysis presented in this paper indicates that the semi-empirical procedure works well; however, variations in the procedure and/or an insufficient amount of testing could lead to underestimations of the inflow quantities. Packer test data plotted in histograms were observed in all cases to be log-normally distributed for the radial flow condition. Modeling using Monte Carlo simulations was observed to be an effective tool for removing irregularities in the distribution of the data and incorporating high-end permeability data to derive reasonable groundwater inflow estimates. This paper is based on the PhD thesis entitled “Improvements to the Current State of the Practice in Steady-State, Groundwater Inflow Estimates into Rock Tunnels based on the Application of Statistical Analysis Methods of Packer Test Data obtained from Exploratory Borings During Geotechnical Site Investigations.”

Oct 9, 2020