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By C. H. Lau, I. T. Ng

Uniaxial Compressive Strength (UCS) of rocks is an important mechanical parameter for many civil engineering and rock engineering applications such as tunnel excavation, slope stability and foundation design. Macau is one of the world's fastest growing and most densely populated cities, many large and important infrastructures have been being continuously built using pile foundations which are designed to be supported by granitic bedrock. In Macau, the UCS of the granitic bedrock is required almost for every project involving pile foundations and is always measured directly from UCS test in the laboratory. However, direct measurement of UCS requires high quality rock core sample which is not only time-consuming and expensive but also requires high level of operating skill. In view of this fact, estimation of UCS using some empirical correlations will be more practical and efficient because they are relatively fast and economical compared to the direct measurement from UCS test. In the past, some empirical correlations had been established and widely used for estimating UCS of rocks in common engineering practice. However, it has been well recognized that the rock properties are generally varied with sites or geological regions in other words an empirical correlation developed from one region or one country may not be applicable for other regions or countries. Due to the reason that the empirical correlations for predicting UCS for granite are scarce in practice, in this study an extensive experimental program has been performed and a large database containing data such as UCS, Point Load Index (Is50), Schmidt Rebound Hardness (RL), porosity (?), water absorption (S), specific gravity (Gs) and dry density (?d) has been developed. An attempt has been made for developing a new empirical correlation for estimating the UCS of Macau granite. Accordingly, a comprehensive statistical analysis for correlating UCS with Is50, RL, ?, S, Gs and ?d has been performed and a local empirical relationship based on the developed database is proposed for obtaining reliable estimation of UCS for the granite of Macau. Finally, the performance of the proposed correlation is accessed by using another independent testing database developed in this study. It indicates that Is50, RL, ? and S have strong correlation with UCS whereas Gs, ?d have poor correlation with UCS. This study not only proposed a proper predictive empirical correlation for UCS determination for Macau granite but also provides detailed statistical information which is beneficial to engineers for obtaining better characterization of Macau granite.

Jan 1, 2015

By N. L. Piret

In copper smelting minimization of solid waste generation is receiving increased attention with more stringent environmental legislation and lower disposal space availability. Copper smelting slags generally being valorizable, solid waste generation is attributed to the presence in the feed of unvalorizable impurities which do not report to the slag and to the unavoidable formation of contaminated dilute acid solutions which need neutralization. As to unvalorizable impurities, solid waste minimization is achieved by rejecting them in the highest possible concentration. Dilute acid is mainly due to the formation of SO3 in the smelter gases and to the discard of decopperized bleed-off electrolyte. Its generation is substantially lowered by preventing SO3 formation, by converting the dilute acid to a valorizable product, e.g., by thermal decomposition for H2S04 recovery or by precipitation as chemical gypsum, and by suitable treatment of the bleed-off electrolyte for impurity removal. Industrial processes are evaluated and alternatives are discussed.

Jan 1, 1994

By H. Lyn Bourne

This is the fourth annual tabulation that gives mineral royalty information. The table presents previous information plus about two dozen new entries. In addition to the royalty information, some entries show the cost of purchased reserves. Last year's tabulation appeared in two issues, to accommodate all of the information. This year the format has been changed slightly so the table can be printed in one issue. This year's table presents the commodities in the same sequence as last year. Sand and gravel information appears first, followed by: crushed stone for aggregate; other stone; industrial sand; other industrial minerals; energy minerals (coal, oil shale, uranium); and finally metals. As always, a caveat relates to factors that influence the reserve values. The data should serve only as a general reference. The table is not intended to present an absolute scale of reserve costs. Several factors influence the value of mineral commodities. These factors include: • location and transportation costs (especially significant for most industrial minerals); • market conditions for both the commodity and the company acquiring the right to mine it; • quality or grade of the deposit as it reflects the amount of processing and beneficiation necessary to produce the finished product; • and legislative restrictions and conditions for mining a given material at a given site. These and other factors will influence reserve costs of reserves. The table shows the range of royalties and the variations in the basis of computing the fees. In a few instances, it gives the cost of acquired reserves based on purchase price and quantitative estimates of the material in place. The table lists the commodity; the location (either by state, US geographic area, or Canadian province); the cost (R for royalty and P for purchased cost); and the year in which the lease or purchase agreement occurred. The last column offers either comments or gives a footnote number for more information. The cost column requires more explanation. The units may refer to cubic yards (/yd), cubic feet (/cuft), tons (/T) (2000 lbs) or acres (/A). 1 cu yd = 0.76m3 1 cu ft =0.28m3 1st = 0.9 t7 1 acre = 0.40 ha or m2 In several cases the royalty is a percentage of the finished products, sale price and is levied against either the amount produced or the amount sold. We thank those who contributed information for the table: J. Dunn, T. Eyde, K. Loda, L. Morgan, F. Nix, H. Sorenson, and L. Williams. Several people have said they would like this to be an annual tabulation. That can happen if new information comes to the writer. What appears in the table is only a very small fraction of the cost information relative to the various commodities and the geographic areas for which there is royalty information. If you find this column of interest and possess information write or call: H. L. Bourne, c/o Neyer, Tiseo & Hindo, Ltd., 38955 Hills Tech Dr., Farmington Hills, MI 48018, (313) 553-6300. Only with new information can this become an annual and current source of reserves costs.

Jan 8, 1986

By R Zavadil, S Kuyucak, F Fazeli

Proton exchange membrane (PEM) fuel cells generate electricity by reacting hydrogen and oxygen. A thin, bipolar electrode material provides a medium for electron exchange with the electrolyte, alternately serving as anode at the hydrogen-rich side and cathode at the oxygen-rich side. Stainless steels have sufficient corrosion resistance to qualify as bipolar plate materials. However, the protective chromite layer increases the contact resistance, the battery’s internal resistance; and thus, decreases the electrical efficiency of the fuel cell. A heat-treatment is proposed and investigated via simulation by ThermoCalc / Dictra and experimentally, to generate a sufficient quantity of conducting surface carbides that breach the protective layer. Once carbide growth is arrested, a subsequent heat-treatment is also needed at a higher temperature to restore the corrosion resistance by filling-in the Cr-depleted layer (sensitization) around the carbide particles.

Jan 1, 2014

By Madan M. Singh

The use of fluid jets for industrial purposes has received considerable attention in recent years. The convening of The First International Symposium on Jet Cutting Technology1 in April 1972 devoted solely to this subject probably heralds the coming of age of this new science. It is interesting to note the emphasis in the conference towards the cutting of rocks, minerals, and soils, indicating the attention being devoted to excavation and mining. The use of water streams for mining of minerals is not new. It is well over a century since its first application.2 But its use in coal mining has been somewhat restricted over the years. In the past 30 years the U.S.S.R. has successfully used water for coal extraction, and these techniques have been examined in 15 countries in recent years. In the United States research on various aspects of the method has been conducted for over 15 years,3 but success stories from the Soviet Union,4 JapanS and Canada6 in the last 5 years has spurred greater enthusiasm. IIT Research Institute has done pioneering work in the 7-12 13-15 area of water jetting for rock and coal breakage. It has just completed an experimental study involving mining of coal with a 50,000-psi and 100,000-psi jet in a stripping operation14 under the sponsorhip of the U. S. Bureau of Mines (Contract No. HOll1789). As a complementary program the Bureau initiated a project to design a water-jet coal-mining machine (Contract No. H0133119). IITRI was a successful bidder on this competitive procurement.

Jan 1, 1974

By G. W. Jones

Explosion hazards that may exist when air becomes polluted with combustible gases and vapors are extremely dangerous, particularly if the volume of gaseous atmosphere is large, and an explosion under such circumstances could do tremendous damage to persons and property. The hazard is even greater if explosive mixtures are confined under high pressure, as the pressure could increase to tremendous proportions just before the container would rupture. Because of its interest in safety in the mining and allied industries, the Federal Bureau of Mines has investigated the flammability (explosibility) of various types of combustible atmospheres and published its findings. The explosibility of natural gas has been studied, and the limits of flammability have been determined and published. Other investigations have shown how explosions of natural gas-air mixtures may be prevented by the addition of nitrogen and carbon dioxide.

Jan 1, 1949

By J. Grumer

The Bureau of Mines, under the sponsorship of the Space Nuclear Propulsion Office, conducted a laboratory-scale hydrogen safety study which determined several combustion characteristics of hydrogen diffusion flames. Experiments show that ambient air may enter the top of a hydrogen flare stack when the hydrogen flow is low. A new concept, supported by photographic evidence, predicts that diffusion flames burning in air on a wide, upright pipe (stack) and fed with slow, upward flows of buoyant gas will induce a downward flow of air along the walls of the pipe that can support combustion within the pipe. Predicted flamedip limits agree roughly with experimental values determined on 6-, 12-, and 18-inch-diameter stacks and increase with increasing stack diameter. Measurements were made of the limiting flow at which a hydrogen diffusion flame blows out in still air. By means of an empirical application of the critical boundary 8 velocity gradient concept, these data lead to a blowout limit of about 10 reciprocal seconds for a hydrogen diffusion flame. Burning rates of large hydrogen diffusion flames ranging from about 0.03 to 1 ft/sec were used to predict approximate flame heights on flare stacks. Temperatures of larger hydrogen diffusion flames up to about 3,600° F were observed, but the most representative value appears to be about 2,600° F. It was found that crosswinds do not strip significant amounts of unburned hydrogen from its diffusion flame and that water-cooled flare stacks are not likely to be damaged when flame is blown back into them by opposing winds.

Jan 1, 1970

By Michael A. McNicholas

"Deep foundations utilize the varying soil conditions to provide the most cost-effective or practical scope for a given jobsite. Once the scope has been determined and the engineering applied, the element can be installed and tested to determine if it is suitable. QA/QC programs are vital for the assurance that the element designed by the engineer has not only been properly constructed but that the design assumptions are confirmed. The two deep foundation elements referenced are drilled displacement piles (DDP) and micropiles. Each of these elements allows for large loads to be distributed deep into the subsurface geology. Having the technology and ability to monitor the tests in real-time can be beneficial to a contractor in determining if the design is adequate or if adjustments need to be made on future piles. The proper QA/QC guidelines for installation and monitoring need to be in place to ensure that an accurate interpretation can be made on the pile. This paper discusses the typical testing and the positive results that the author has encountered using the latest advances in strain analysis.KEY TERMSDrilled Displacement Piles:A deep foundation system that has the ability to shed load into the geology through shaft resistance as well as tip resistance, similar to drilled shafts. This pile element is unique in that it has a consistent pile section and thus a consistent modulus of elasticity.Micropile:A deep foundation system used in applications where the foundation lies over material not suitable for a spread footing and the ideal soil stratum is deep below the foundation. Micropiles will have two different cross-sections consisting of a cased section and an uncased section. For this reason, this pile type requires additional analysis when computing stress-strain relationships.Geokon Strain Gauges:Instrumentation such as Models 4911A-4911 Vibrating Wire Strain Gauges ( known as Sister Bars) are designed to be embedded in grout and calculate loads based on the change on grout strain over a period of time.Stress:A pile element is under a compression (axial loading) load when a force acts along its axis and is normal to the plane of the section. The corresponding stress the pile is experiencing is described as a normal stress. The stress is obtained by dividing the magnitude of the load distributed over the cross-section by the area of the pile cross-section, as shown in Eq. 1."

Jan 1, 2017

By A. U. Seybolt, R. E. Honnemon

THE purpose of this communication is to present activity data of nickel in the Ni-A1 binary system that was obtained for oxidation studies in this system. This data has been calculated from previous aluminum activity data at 1000°C1,2 by two types of Gibbs-Duhem integrations. These results should be of particular current interest to oxidation studies of aluminide coated nickel-base superalloys3 as well as other problems. The aluminum activity of Steiner and Komarek1 is plotted in Fig. 1 as a function of composition in Ni-A1 alloys at 1000°C. The dashed parts of the aluminum curves represent our approximate extrapolations from the directly measured regions. In the terminal solution regions (a and L phases) standard parabolic solution functions of the following form are assumed: where i is the component subscript, Ki is a constant at a fixed temperature, and xi is the atom fraction. The resultant nickel activity curve at 1000° C from the Gibbs-Duhem integration4 of the aluminum data is shown in Fig. 1. The solubility ranges of the phases present in the Ni-A1 binary at 1000°C are also denoted at the bottom of Fig. 1. Corresponding values of the nickel activity, aNi and yNi, are listed in Table I at useful compositional intervals. including phase boundary values. The aNi and yNi data listed in Table I are subject to the uncertainties present in the experimental aluminum activity data1 and to deviations from parabolic solution behavior in the terminal solutions. The errors introduced into aNi and yNi due to the parabolic solution assumption are expected to be relatively small (<20 pct of the values given) in all the phases except the liquid phase. Some deviation from parabolic solution behavior in the liquid phase is indicated

Jan 1, 1970

By D. R. Tesarik, T. C. Trancynger, W. G. Pariseau

The Davis detector cavern was excavated on the 4850 Level of the former Homestake Mine in the mid- 1960s to house a novel neutrino detector developed by Nobel Prize winner Dr. R. Davis. The original cavern was about 9.1 x 16.8 x 9.7 m high, excavated in a Precambrian amphibolite known as the Yates unit and enlarged in 2010. In 2009, the National Science Foundation selected the site for development as a national Deep Underground Science and Engineering Laboratory (DUSEL). This retrospective rock mechanics study of the Davis cavern is intended to inform design of the much larger caverns and laboratory rooms being considered for the same 4850 Level. Provision for rock mass variability, sequential excavation, jointing and wall damage from blasting are included in analyses that were done using two different computer codes and methods (FLAC3D and UTAH3). The results are in agreement with observations and show that cavern stability is indeed the case. The main conclusions are: (1) if conventional scaling of laboratory rock elastic moduli and strengths is done, then 0.25 and 0.50 scale factors are reasonable, (2) measured statistical and spatial variability in rock properties should be incorporated into geomechanical analyses to better reflect reality, (3) discontinuities (“joints”) are essential to reliable analysis of excavation safety and when properly taken into account eliminate the need for empirical “scaling” of laboratory rock properties, (4) major geologic features such as rhyolite dikes and breccia zones may be important to excavation safety at Homestake and should be explicitly represented in analyses and (5) quantifying wall blast damage is important to engineering design of underground excavations.

Jan 1, 2012

By J. T. Tanner

The research activities of the Minerals Research Laboratory, which is a part of North Carolina State University, is normally confined to solving beneficiation problems, and developing flotation processes for the mining industry. In recent years the laboratory has veered from its main purpose somewhat and has placed some emphasis on the manufacture of products from mineral concentrates. This has been the result of requests for help from industry. One such request came to the MRL from a talc producer in North Carolina who was having a difficult time competing with foreign imports of steel marking crayons. He felt that if a process could be developed whereby a satisfactory crayon could be produced from powdered talc at a low cost that he could compete.

Jan 1, 1986

By L. M. Pero

The paper summarizes aspects of the recent literature on mineral development in the Third World. The emphasis is on publications covering agreements between host governments and mining companies.

Jan 1, 1985

By E. J. Duggan

CLIMAX ore is an altered and highly silicified granite, about half of the gangue being quartz. Molybdenite is the only mineral recovered and most of it is intimately associated with the quartz in fine veinlets. Other minerals are molybdite, pyrite, and chalcopyrite. Although the molybdite may be readily extracted by hydrometallurgical methods, its content is too low to make this profitable. The pyrite ranges from 2 to 5 per cent and the chalcopyrite from 0.03 to 0.05 per cent. There is not enough copper to make its recovery attractive and one of the problems is its elimination, and that of pyrite iron, from the final product. On account of the high degree of dissemination of the molybdenite and the necessity of eliminating the iron and copper, fine-grinding followed by flotation is the only known feasible method of concentration. Two factors, peculiar to Climax ore, have a predominating influence on the metallurgical attack: (1) Molybdenite is one of the most easily floated minerals. High recoveries may be made with pine oil alone if the

Jan 1, 1946

By D. B. Taliaferro

[Recovery of core specimens from subsurface formations and their subsequent analysis are important aids in efficient development and operation of oil and gas fields. Core specimens first were obtained mainly for the geologic information they revealed; now they are analyzed to determine many of the physical characteristics and conditions of tae subsurface formations as well. Cores recovered from the producing formations may be analyzed for porosity, permeability, oil content, "connate" water content, and other physical and chemical properties of the formation, all to the end of furnishing enough data for making reliable estimates of the quantity and availability of oil and gas within a reservoir and in devising, efficient means for their withdrawal.]

Jan 1, 1939

By O. Lundhede

Today, systems and machinery usually are designed to meet only one specific customer?s requirements. One reason for this is that underground automation and smart functions are often developed tightly together with a customer. This is natural, since risk and cost can be shared between the customer and the supplier. Nevertheless, when the automation product develops and the market increase this will cause problems: The highly specialized products will not fulfill the next customer?s demands. In order to cope with this problem, Atlas Copco works towards a common platform. Instead of designing solutions for specific customers, we will lift the abstraction and focus on standardized modules. These modules, or function blocks, can then be combined in a large variety of configurations. The benefits of combining modules into products are, for example: increased flexibility when options are available for many machines; easier commissioning and maintenance since less different spare parts and tools are needed; and easier operation since the user interfaces have a similar look and feel. This paper will present the ongoing work towards standardized modules. We will discuss how our Rig Control System (RCS) allows for modular design at Atlas Copco. RCS has number of standardized modules that are used in different surface and underground mining and tunneling equipment. These modules are also used for optional products such as, drilling, radio-remote control, and telematics systems.

Aug 1, 2013

By D J. Bradshaw, B Lottermoser, A Parbhakar-Fox

"Best practice for acid rock drainage (ARD) risk assessment still relies solely on the geochemical properties of sulfidic rocks and mineral processing products, despite the fact that a rockÆs tendency to produce acid also depends on mineralogy and texture. Consequently, there are a plethora of geochemical tests routinely utilised by the mining industry to predict ARD formation. Due to limitations associated with these tests and their relatively high costs, analysis of recommended best practice sample numbers is rarely achieved, reducing the accuracy of waste management plans. Our research addressed this through examining the application of geometallurgical data for predicting acid formation, and led to the identification of potential environmental geometallurgy indicators.Samples obtained from an iron-oxide copper gold deposit were subjected to the geochemistry-mineralogy-texture (GMT) approach, an improved methodology for classifying acid forming potential. GMT results were compared against geometallurgical and assay data sets to evaluate: relative carbonate content measurements (measured by HyLogger) and identify how these could be used to calculate effective acid neutralising capacity mineral hardness (measured by EQUOtip) to determine application of this data for calculating lag-time to acid formation opportunities to automate the acid rock drainage index (ARDI) using classified images produced by a GEOTEK logger and automated microscopy.Links between the GMT approach and geometallurgical data sets were identified. Classified mineralogy data has application at stage one, HyLogger and EQUOtip at stage two and computer-based ARDI evaluations of classified images at stage three. Through such integration, ARD characterisation costs can be reduced, with value added to geometallurgical data sets. Furthermore, deposit-wide ARD domaining is possible, and acquisition of total-orebody knowledge more likely. Through adoption of this environmental geometallurgy approach, a better informed waste management plan can be formulated, allowing for best practice ARD sampling in a more cost-effective manner.CITATION:Parbhakar-Fox, A, Lottermoser, B and Bradshaw, D J, 2013. Cost-effective means for identifying acid rock drainage risks - integration of the geochemistry-mineralogy-texture approach and geometallurgical techniques, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 143-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By Steve Kral

The concept of sustainable development is not new to the mining industry. Many people involved with mining have argued that the industry throughout the world has always supported the communities where they operated. They say that the mining industry was employing sustainable development practices before the phrase became fashionable. The mines employed residents and supported the local economy through tax payments and the purchase of goods and services from local businesses. In many cases, mining companies have built medical facilities and contributed money, equipment and services to local schools. In modern times, mining companies have donated reclaimed land to the local communities for use as parks and recreational facilities.

Jan 1, 2004

By C. W. Elder

"INTRODUCTION This report describes a method of horizontal drilling in an oil-producing formation underlying a 400-acre, approximately square plot of land in the Franklin Heavy oil field in Sugar Creek Township, Venango County, Pa. The method, which was developed on two previous projects in Ohio, 3/ consists of sinking a shaft to the bottom of a shallow oil sand and drilling holes in a general horizontal plane outward from the chamber in a pattern similar to that of the spokes of a wheel. The project was undertaken by the Venango Development Corporation in an attempt to find an efficient method of recovering oil from partly depleted sand formations.The Venango Development Corporation is composed of the following oil-producing and oil-refining companies and individuals: South Penn Oil Co., Forest Oil Corporation, Kendall Refining Co., Minard Run Oil Co., Quaker State Oil Refining Co., The Pennzoil Co., Alliance Oil Corpo¬ration, United Refining Co., Franklin Creek Refining Corporation, Canfield Oil Co., Pennsylvania Refining Co., Page Oil Co., Freedom Oil Co., D. W. and D. S. Grant, and J. P. Herrick, C. M. Davison and N. V. V. Franchot. Engineering features of the project were supervised by a committee off three engineers A. J. Saxe, chairman, W. M. Shoemaker, and C. N. Pfohl, who supervised the excavation of the shaft and the drilling of the first two holes by alternately spending a week at a. time at the project. The drilling method was under patent license from Leo Ranney, who served as technical advisor to the Venango Development Corporation; in addition, he furnished the design for the shaft and work chamber."

Sep 1, 1944

By A M. Sardo, D E. Sinnett

This study uses the Q Method to examine how those living in former metal mining landscapes value this heritage and their preferences for the long-term management of mine waste. Such sites are often perceived as derelict or degraded, and of very little value. It is therefore assumed that their reuse, for example for development or recovery of metals, is likely to be beneficial. There are around 5,000 former metal mines in England and Wales, many of which are protected for their ecological, geological or cultural value. The Q Method is particularly suitable for issues where there is no consensus of opinion. We asked 38 residents of six mining areas in England and Wales to ‘sort’ a series of statements based on their resonance with the resident’s perspective; this is the Q sort. The statements covered a range of opinions of the mining legacy, its value and options for its management with a particular focus on the potential for metal recovery from the wastes. Analysis of the Q sorts revealed five perspectives on the mining heritage. All placed a high value on the cultural and ecological value of this heritage, however, they differed in their priorities for long-term management. For example, emphasis was placed on either nature conservation, cultural heritage, water quality or the opportunity for job creation through reworking the mines. Cutting across these themes there were also differing perspectives on the role of experts and local people in shaping the future management of the wastes. This research suggests that the views of local people are nuanced; they value their mining heritage but opinion is split on the most effective way to manage these sites especially where there is an impact on water quality.CITATION:Sinnett, D E and Sardo, A M, 2018. Former metal mining areas in England and Wales – local residents’ preferences for the management of wastes, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 126–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

"In addition to outstanding technical sessions and networking opportunities, the SME Annual Conference and Expo offers attendees a chance to see the latest and greatest technology that the industry has to offer. The 2017 SME Annual Conference and Expo was no exception as 575 companies filled 756 booths from Feb. 19-22 in Denver, CO. The following is a look at some of the vendors that were on hand.AIL MiningThe Edge, featured by AIL Mining at the 2017 SME exhibit, is a four-flange structural liner designed to be an alternative to structural plate’s traditional lapped seams and to help mine operators build more efficiently and safely. It is ideal for creating underground structures, such as mine shafts, ventilation raises and escape ways. The Edge is available on SuperCor structural steel plate — 10 times stiffer and five times stronger than traditional steel liner plate. It facilitates curved structures, both horizontal and vertical, and eliminates the need for ring beams. It is ideal for remote sites. For added safety, structures can be assembled from the inside, and the leak-resistant structures can be dismantled and removed easily. Brackets can be attached to mine shafts or vent raises to support Alimak rails or climbers. Similarly, brackets or hangers can be attached to drifts or tunnels to support mine air, water or electrical utility services.ArcadisMining companies spent nearly $12 billion on water infrastructure worldwide in 2014, reflecting the industry’s heightened concern about environmental issues and social, regulatory and political risks.So, with an increasing focus on water reuse and recycling, mining companies must have effective water management plans that include sustainable solutions. Also, many water quality issues fall under both state and federal regulatory jurisdictions. To solve these problems, Arcadis provides comprehensive ground- and surfacewater technical support in a complex hydrogeologic setting. It can characterize the nature and extent of mine-related constituents in ground water and surface water, as well as the complex interactions between the two waters, and prepare the operational permits needed by mine and tailings facilities. As an example, Arcadis constructed a hydrogeologic and geochemical conceptual site model that improved site understanding for a molybdenum mine in the western United States that spanned several watersheds. It also provided technical support for permitting and compliance issues, allowing the mine to return to active production."

Jan 5, 2017