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By W. H. Langer

Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

Jan 1, 2009

By Paul D. Tomlingson

During the next several months, SME’s E-Newsletter will feature 15 articles on maintenance management. The articles may be read online or downloaded and distributed within your organization. They will address maintenance management topics, offer guidelines to mining managers and provide techniques that the maintenance manager can use. The articles will stress equipment management, a strategy that the mining industry has accepted as a modern replacement for outdated maintenance practices. Equipment management is the mutually supportive interaction of all mine departments as they establish equipment needs, procure equipment, test, commission, operate, maintain, modify and eventually replace equipment. The successful application of equipment management principles can quickly and reliably produce cost reduction and performance improvement results while providing a dependable way of sustaining them. Equipment management embraces modern management techniques. These include reliability-centered maintenance, life-cycle costing, capital performance, the effective use of information and productive organizational models.

Jan 1, 2003

By R. Owen

An overwhelming amount of data can be collected around the blasting process. This information can include blasting product, pattern design, blast results, and routing. It is only when these data sources are combined in a concise and accurate form that they are of real use in determining the safety and economic implications of each parameter. Two key technological aspects of blasting are drill fleet management (DFM) and size fraction analysis (SFA). As these technologies are integrated as near-real-time measurement and QA/QC tools, the resolution and realization of blasting parameters is significantly increased. The Freeport-McMoRan Morenci Mine has integrated these technologies along with other existing database structures to create a responsive and sustainable tool for reconciliation, forecasting and parameter matching. This ability allows Morenci to customize blast patterns to meet the criteria most critical to each shot, whether the impact is influenced by routing and recovery, equipment maintenance or safety concerns. DRILL FLEET MANAGEMENT The current DFM was stabilized in its current form in mid 2009 after database and hardware maintenance met stability requirements. Currently the system is running on 12 production drills. The system receives pattern layout and is capable of semi-autonomous drilling over the entire district. The fleet is capable of drilling in highly altered intrusive units and hard granites through the range of sedimentary and volcanic units that comprise the Morenci District. The system brings a level of accuracy not achievable with earlier paint-marked patterns. Depth control is also increased along with more consistent wear and maintenance patterns due to semi-autonomous drilling.

Jan 1, 2011

By Staff

The mineral sector is a fundamental part of the U.S. economy. It contributes to the real gross domestic product (GDP) at several stages—basic (mining), intermediate processing, manufacturing of finished goods and construction. The estimated growth rate for the real GDP of the United States for 2006 was 3.2 percent. The nominal GDP was about $13.2 trillion. The value of minerals mined in the United States in 2006 rose significantly because of increased unit price for some metals—particularly copper, zinc and other base metals. There was also a significant reduction in metals stocks. Infrastructure expansion and manufacturing in China and India have been absorbing a significant portion of world output. Domestic production increased for some industrial mineral materials, mainly cement and construction sand and gravel. Production of crushed stone declined less than 1 percent in 2006 compared

Jan 1, 2007

By P. James

"INTRODUCTION Control of target stream pH is very important in leach mining and treatment of MIW (mining influenced water). On the production side, solution acidity can impact SX (solvent extraction) effectiveness through PLS (pregnant leach solution) and raffinate pH. Many older operations and legacy mining sites generate ARD (acid rock drainage) that is too weak for profitable metal production by conventional means and faces costly wastewater treatment for mitigation and disposal. For wastewater and environmental treatment, neutralization to precipitate and remove metal contaminants to clean the wastewater is the dominant approach. Traditional lime neutralization and precipitation is most often used but results in large amounts of mixed metal sludge requiring costly disposal. Blue Planet Strategies (BPS); which focuses on improved resource utilization targeting electrolytic treatment and waste conversion into resources, has developed a new “reagentless” neutralization process. Electricity is utilized in its proprietary DEMET™ (Dynamic Electrolytic Metal Effluent Treatment) platform capability to controllably raise target stream pH. The method offers a simple, low-cost approach yielding cleaner treatment chemistry. It can result in less sludge generation and enables possibilities to selectively recover contaminants as potentially saleable products for new revenue generation to offset further offset treatment costs. DEMET Overview BPS’s patented electrolytic DEMET platform leverages solid scientific and chemistry foundations through its advanced design to achieve capabilities and performance not previously realized. DEMET technology combines separated compartment electrolytic cell functionality with proprietary advanced dynamic electrodes and cell configurations to achieve a variety of chemistries and processing targets.[1-6] DEMET‘s unique elements can yield higher processing rates at practical efficiencies, lower energy consumption, plus improved processing stability and lower maintenance requirements due to enhanced resistance to cell fouling and shorting; while also thwarting cross stream (catholyte vs. anolyte) contamination. Consequently, DEMET can provide a superior, extremely versatile, and more cost-effective electrolytic treatment option where a multitude of FEED and PRODUCT stream combinations might be employed in comparison to traditional tankhouse electrolytic cells."

Jan 1, 2015

By Ross W. Smith

In recent years there has been a considerable amount of research work done relative to the effect of pretreatment and aging in water on the surface properties of both simple metal oxides and more complex oxides such as the silicate minerals 1-6. Of particular interest is the work of Somasundaran6 who states that after preparing minerals by size reduction and washing with dilute acids "... it is essential to treat it (the mineral) with water in order to remove any effects of leaching itself." Somasundaran also states, "... it is advisable to use a solution close to the point of zero charge for conditioning purposes." Parksl notes that, "Dehydration, dehydroxylation, and increased crystallinity can be expected to decrease the PZC. The presence of anionic impurities or of pH-independent potential determining ions will decrease the PZC. Cationic species will increase the PZC." Healy and Jellett4 believe that in the Zn0-water system "the surface charge of Zn0 in water and each pH is determined by the concentration and adsorption of each hydrolyzed (charged and uncharged) Zn(II) species." Finally, according to Parks 2, "The PZC of an unaltered com¬plex oxide in a system devoid of specific electrolytes is approximately the average of the PZC's of its component oxides... Equilibration with water results in loss of mono and divalent cations by exchange with H+, thus a loss of influence on the PZC by those cations, i.e., a shift in the PZC with time in the direction of that remaining oxide. The present paper investigates the change of point of zero charge (PZC) of a number of simple oxides and several complex oxides as a function of aging time in water. In some cases acid pretreatment of minerals was performed. However, in most cases the minerals were not acid pretreated. In several systems pH change as a function of aging time in water was monitored.

Jan 1, 1972

By Li Zhou

The kinetics of the dissolution of galena was studied by monitoring the mixed potential of a galena electrode in ferric sulfate solutions. The results show that the mixed potential of the galena electrode fluctuated with time in a regular pattern in a 0.1 mol/L Fe2(SO4)3 solution of pH 1.66 and in a 0.01 mol/L Fe2(SO4)3 solution of pH 2.33 at 35°C. The periodic accumulation and precipitation of lead ions at the galena electrode surface and the cyclical variation in pH at the galena electrode surface caused the oscillation phenomena.

Jan 1, 2008

Ceremonies for the induction of five mining industry pioneers into the National Mining Hall of Fame are scheduled for Saturday, Sept. 25, 2004 at the Las Vegas Hilton in Las Vegas, NV. The 17th Annual Mining Hall of Fame Induction banquet will begin with a reception at 6 p.m., followed by the dinner and program at 7 p.m. The five inductees are Georgius Agricola, David William Brunton, Herbert E. Goodman, David Ray Mitchell and Robert Peele. Georgius Agricola (1494-1555) wrote De ReMetallica, an original and valuable work that discussed everything known about mining during the first half of the 16th century. In De Re Metallica, Agricola reviewed practical means of finding ores, methods of surveying and mining, the assaying of ores, types and uses of mining machinery, smelting, mine administration and more. David William Brunton (1849-1927) is best know

Jan 1, 2004

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 A. Bobet

Design of a new underground laboratory is underway through the auspices of the United States National Science Foundation. The Deep Underground Science and Engineering Laboratory (DUSEL) is scoped to provide a diverse group of researchers with a dedicated underground facility capable of supporting a broad spectrum of fundamental and applied research at depth in the Earth?s crust. Key research partners in the endeavor are physicists, biologists, geoscientists and engineers. Engineers are not only designing the underground facilities, but are also actively involved in developing research initiatives. This paper will introduce the DUSEL engineering research program to the mining community, provide an overview of the site, geology, and laboratory facilities, and describe some key program initiatives. The particular technical challenges and opportunities afforded by the construction of DUSEL and the performance of the integrated science-engineering program will be discussed by reference to a subset of research initiatives that are currently under development: Cavern Design, CO2 Sequestration and Transparent Earth. These research initiatives target the development of new techniques that can support improved subsurface investigation, design and construction procedures. An increased use of the subsurface can actively contribute to the development of new, more sustainable solutions for use in mining and civil engineering practice.

Jan 1, 2011

By Rod Heath

The Saskatchewan industry has the advantages of an ore body of a size and consistency unmatched anywhere else in the world, and large, efficient mines with production costs that compare favourably with those in other countries. On the minus side, Saskatchewan is remote from most major markets, and producers face a distribution challenge to reach the offshore markets which is the main focus of this presentation. One of the characteristics of the world potash business is that all of the major sources of production are located in the developed areas of the world, while there is no significant production in any of the highly populated developing countries. The major potash producers are located in Canada and the United States, in West Germany, France, Spain and the U.K., in Russia and East Germany, and in Israel and Jordan. There is currently no significant production in any of the countries in Asia (with the exception of Jordan where a plant is currently in the start-up phase), Africa, Latin America or Oceania, and all of these areas must, therefore, import a11 of their potash requirements from the producing countries.

Jan 1, 1985

By X. Zhou

In this study, the cyclonic static microbubble flotation column (FCSMC) was investigated for fluorite beneficiation. The structure and principle of the specially designed column are described. Fluorite samples from the tungsten separation tailings of the Shizhuyuan Mine, Chenzhou, Hunan Province, P.R. China, were tested using a small-scale continuous flotation test unit, and concentrates with a fluorite grade higher than 98% were obtained. One rougher and three cleaner stages in the FCSMC achieved the same separation performance as one rougher and eight cleaners in conventional flotation cells. This greatly simplified the flotation circuit and reduced operating costs.

Jan 1, 2007

By H. R. Butler, J. F. Church, A. T. MacGibbon

Introduction Inco is the major North American nickel producer. Initially based in Sudbury, Ontario, its past exploration activity was directed toward finding new nickel deposits. New nickel sulfide discoveries outside Sudbury have included Thompson, Manitoba; Shebandowan, Ontario; and Widgiemooltha in Western Australia as well as a host of nickel laterite deposits. The company is currently diversifying into other commodities, including gold. Inco's exploration department participated in uranium discoveries in Saskatchewan and chromite discoveries at Tiebaghi in New Caledonia. In addition, it found new gold deposits at Lupin, Northwest Territories; Crixas, Brazil; Hoyle Township, Ontario; and Casa Berardi in Quebec. Crixas and Casa Berardi are currently being evaluated by underground exploration. Figure 1 shows some Canadian Shield gold locations where Inco is or was an active participant. Base metal developments Base metal exploration in shield areas has been greatly eased by applying scientific studies. Archean nickel sulfide deposits have been found using komatiitic-flow models (Fardon, 1971). Volcanogenic massive sulfide model has been applied to copper-zinc deposits (Sangster and Scott, 1976). Such deposits were subsequently seen developing on the sea floor through black smokers (Spiess, MacDonald, and Atwater, 1980). Sedimentary processes were recognized early as important in ore formation, particularly in the southern hemisphere (King, 1976). And many ore deposits are now regarded as a simple part of the geological column (Stanton, 1960 and 1972). Petrographic work on alteration patterns in and around ore bodies was used to develop standard porphyry copper models (Lowell and Guilbert, 1970). Epithermal models for precious metals followed. Stratigraphic zonation patterns have been formulated for base metal deposits, including keel facies, ore facies, and cap or distal facies. Gold developments The work on base metal deposits naturally spilled over into precious metal exploration when the gold price was allowed to float on world money markets. Early work on elements associated with gold deposits, especially arsenic, tellurium, selenium, and mercury, pioneered more detailed geochemical work (Bagby and Berger, 1985; and Groves, Ho, and Houstoun, 1984). Geochemical patterns have been recognized around microfine gold deposits. And the study of gold precipitation patterns in modern geothermal systems has helped understand gold deposition. In the late 1960s and early 1970s, it was noticed that numerous Archean banded iron formations contained anomalous gold values. From this and other observations, the syngenetic exhalite gold model has developed. Gold deposits also occur along shears in some plutons such as the Belmoral mine in Quebec. This indicates the importance of epigenetic processes in ore formation. Shield ore settings Initial studies recognized that the major gold camps in the Canadian Shield were mostly in greenstone belts and found along "breaks," especially zones of faulting and sedimentation. Gill (1948) wrote, "Only recently, as a result of detailed mapping, has the importance of major schist zones such as the Larder Lake, Cadillac, Porcupine Creek, and Destor Breaks been recognized. These zones of persistent adjustment mark broad belts favorable for ore occurrence." The importance of shearing in ore location and regional greenstone stratigraphic position close to late sedimentary packages was clearly understood. And structural models have been further developed for some Canadian ore deposits (Hubert, Trudel, and Gelinas, 1984). In the Beardmore-Geraldton camp of northwest Ontario, the importance was soon recognized of fold noses in banded iron formation, as localizers for gold ore. This importance had also been recognized in Western Australia,

Jan 2, 1987

By David M. Spatz

The way people interact, collaborate, learn and improve can have a profound impact on a company’s efficiency, performance, productivity and return on investment. This is the motive behind corporate efforts today to replace the traditional hierarchical structure with team-oriented organization. The increased importance of communication and collaboration during the past 20 years has been propelled by rapid advances in technology and increased availability of information. Companies must take advantage of the information that is required for competitive performance and for the continued production of quality products. So it is essential that outstanding communication, cooperation and collaboration take place among multidisciplinary specialists assigned to work together to solve common problems and achieve common goals. Companies are searching for ways to increase knowledge transfer and learning, particularly among people who work on related topics. This will improve efficiency and quality and reduce redundancy and costs.

Jan 1, 2000

By Pat Wilmoth, Joseph P. Gildner, Dan Nowak, Shane Yanagisawa, Don Z. Painter, Gordon F. Revey

Frontier/Traylor is presently completing construction of twin tunnels for the Tri-County Metropolitan Transit District of Oregon’s (Tri-Met) westside lightrail system. The tunnels are each 4,550 m (14,935 ft) in length and 6.48 m (21.29 ft) in diameter. The 1/3 of each tunnel was driven from the west portal using drill and blast methods and the remaining 2/3 was driven from the east portal using a TBM. The paper describes: The difficulties encountered by the TBM mining the weathered Columbia River Basalts. The execution of drill and blast work despite challenging ground conditions, stringent noise and vibrations specifications, and public relations problems. The excavation and lining of the Washington Park Station 79 m (260 ft) below the park zoo.

Jan 1, 1997

By Landy Stinnett

"When performing a valuation of a mineral property, a developing mine or perhaps an ongoing operation, the appraiser is typically provided with a range of information prepared by the property owner. This information can include ownership records, geological interpretation, assay data, an estimate of the reserves or resources believed to be on site (tons and grade), mine plans, production forecasts, capital and operating cost projections, and so forth.The appraiser familiarizes himself with the data, analyzes the various reports and then prepares the appraisal. There is usually a site visit, and there may be some effort at comparison of the particular mineral deposit with others in the region or with those of similar depositional characteristics, but for the most part, the appraiser is relying on the corporate documents, tempered by his/her experience in the field. Time is usually of the essence, the cost for the assignment has been trimmed, and therefore independent verification of the various components comprising the underlying data base (legal review, redrilling portions of the deposit, collection of new samples, re-assaying, etc.) is unlikely in most situations.In the case of high-value commodities — gold, silver, diamonds, perhaps the platinum-group elements — there have been numerous examples of the property owners attempting to increase the value of their holdings by nefarious methods. Most of these involve salting the deposit in some fashion; i.e., introducing small amounts of the commodity into samples being sent to a laboratory for analysis so that the resultant assay shows a higher grade (Donaldson, 2002; Greeley, 2001; Lechler et al., 2008 and Meech, 2001). Other schemes to enhance the apparent worth of a property include the use of nonstandard assay procedures, incorrect handling or withholding of the underlying information, and false reporting."

Sep 1, 2016

By A. B. Cecala

A few years ago, the National Institute for Occupational Safety and Health and Unimin Corporation developed a clothes cleaning system that is able to quickly, effectively, and safely remove dust from a worker?s clothing without dust exposure to the worker, the work environment, or co-workers during the cleaning process. To perform the process, a worker enters a cleaning booth and activates an air spray manifold which blows the dust from the worker?s clothing. Since the cleaning booth is under negative pressure, all the dust and product removed are contained. In the original design, this dust-laden air was exhausted to a dust collector system. However, since most operations do not have excess dust collector capacity, it was decided to determine an alternative method to provide for a stand-alone cleaning system. This was achieved by ducting the exhaust outside the plant and into the atmosphere. This technique was recently tested and shown to be a viable method to provide for a stand-alone clothes cleaning system.

Jan 1, 2009

By Liaqat Ali Shah, Muhammad Farooq, Zait Ullah Shah, Francisco Rolando Valenzuela-Díaz

Bentonite collected from Nowshera (Pakistan) was treated with NaCl, and the < 2-μm clay fractions were separated by sedimentation process. The textural changes in NaCl treated purified bentonite were compared with raw and physically purified sample. It was detected that the NaCl-treated purified bentonite and the sample purified by simple sedimentation, respectively, consist of sodium-montmorillonite and calcium-montmorillonite as a major clay mineral. The honeycombed-type morphology was observed for both the purified samples; however, the particles of NaCl treated purified bentonite were relatively in a compact form. The particle sizes of both the purified samples were found considerably smaller. The high volume percent of the fine particles was noticed in the NaCl-treated purified bentonite. This attributed that the sodium exchange has a valuable impact on the bentonite dispersion in aqueous media during particle size measurement. The relatively high mesopore area/volume and micropore area/volume and specific surface area (SSA) were detected in purified samples. The NaCl-treated purified sample showed relatively high mesopores area/volume than the sample obtained by simple sedimentation. These changes seem to be originated from either high montmorillonite contents and/or the smaller particle size, which might be produced after the layer rearrangement during the interlayer cation replacement by Na+ ions. The large SSA and high porosity of purified samples particularly the NaCl-treated bentonite suggest their potential use as adsorbents, catalysts, pharmaceuticals, and cosmetics.

Jan 7, 2021

The minerals industry consumes billions of dollars in raw materials, equipment, tools, services and chemicals. The industry, though, has turned overmuch of the research and development (R&D) for these products to manufacturers and suppliers. Now the industry and its suppliers must decide how much R&D the mining industry should be responsible for and what role the suppliers should play. Promoting R&D As a result of the current environment in the mining and minerals industry, there has been a substantial decrease in R&D. Depressed prices, stagnant growth, cost cutting and rationalization are evident.

Jan 1, 2000

By C. B. Kettering

In the early operations of the Inspiration Consolidated Copper Company, which extended from 1914 to 1926, the ore as mined contained principally sulphide copper minerals, manly chalcocite (Cu2S), This ore was milled in a 20,000-ton concentrator and the copper was recovered as a flotation concentrate which, was smelted at the nearby plant of the I ternational Smelting and Refining Company. In those days no attempt was made torecovercopper from any oxide minerals present. As mining operations progressed it soon became evident that the proportion of oxide minerals present would steadily increase, and. it was realized that some method of treatment would have to be developed whereby copper could&apos; be recovered from both oxide and. sulphide minerals contained in the ore. A research program was instituted and after some years of experimental and, pilot plant work a new hydro-metallurgical process was developed whereby it became possible to extract copper from both the oxide and. sulphide minerals in a single leaching operation. The solvent adopted consisted of a mixture of sulphuric acid and ferric sulphate,&apos; Following dissolution, the dissolved copper would be recovered by electrolysis. Also in the process of electrolyzing, spent solutions of sulphuric acid, H2SO4, and. ferric sulphate, Fe2(SOk)3, would be regeneratede and. somade available for continuous reuse. The process appeared to be a success and the decision was made to build a full-sized leaching plant for the future treatment of I spiration mixed ore. Construction was started and the leaching plant was completed in 1926, With the start of ferric-sulphate leaching the Inspiration Concentrator was shut down and, with the exception of a few short time runs has not operated since that time. The ferric sulphate leaching process served. Inspiration well for some 30 years and during that time won a name for itself as a classic example of hydro-metallurgical treatment of mixed sulphide oxide ores. Originally the plant was designed. to process some 7,500 tons per day of a mixed ore containing about 1,2% copper, of which 60% was present as oxide and. 40% as sulphide, Down through the years various improvements were made for the purpose of increasing plant capacity and as well to change the limiting &apos;factor of sulphide-oxide ratio, The final result was a leaching capacity of 9,600 tons per day when treating a 1% copper ore with a reversal of the sulphide-oxide ratio to 60% sulphide and 40% oxide.

Jan 1, 1958