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By N. F. Sather

Results of comprehensive trace element analyses of samples of Illinois #5 and #6 seam coals and the unquenched ashes obtained from gasification of these coals in a Lurgi reactor are reported and discussed. Areas where additional background information is needed for assessment of the environmental impact of trace element emissions from coal gasification are identified.

Jan 1, 1976

By D. J. Miller

Environmental considerations are extremely important in planning and carrying out mergers, acquisitions and real estate transfers. It is not inconceivable that potential or actual environmental liabilities could exceed the targeted company's net worth or the book value of the real estate of interest. It is therefore essential that an environmental due diligence investigation (DDI) be performed to quantify environmental liabilities before sales, mergers or acquisitions. This paper will discuss general procedures used in environmental due diligence investigations. The emphasis will be placed on mergers and acquisitions. It should be pointed out that the procedures discussed in this paper are general and must be modified to fit each particular merger or acquisition under consideration.

Jan 1, 1988

By John B. Gustavson

The mineral deposits found in carbonate facies rocks of sedimentary basins include deposits comprised of the country rock itself such as limestone for chemical uses, dolomite for road aggregate, and a variety of other industrial uses of the sedimentary rock. Exploration for new reserves is generally conducted on basis of outcrop investigation, subsurface drilling, and facies change studies while geophysics and geochemistry are not applied. In contrast, rapid development has taken place in the application of both geophysical and geochemical techniques in exploration for stratiform deposits of zinc, lead, barite, and fluorite deposits. This paper will present case histories and show illustrations from such work in the Mid-Continent region. The Metals Division of International Oil & Gas, Inc. has gathered this experience through work over the last three years along the southern margin of the Eastern Interior platform focusing on the states of Arkansas and Tennessee. The exploration work was conducted partially for the Company's own account, partially in joint exploration ventures with mining companies including International Mogul Mines, Ltd., a Canadian company; Bear Creek Mining Company, a subsidiary of Kennecott Copper Corporation; the Mining Division of W. R. Grace and Company, and Boliden-Preussag Exploration, a Swedish-German partnership. We wish to take this opportunity to thank our venture partners for allowing presentation of the various sections of this paper.

Jan 1, 1976

By G. Wang, L. R. Moore, Y. Xiong, J. Gu

"Quartz is the second most abundant mineral in the earth’s crust. Not only does quartz have many valuable industrial applications, it is also one of the most concentrated gangue minerals encountered in the processing of other minerals. Minerals such as hematite, apatite, calcite, feldspar, barite, and many more. Numerous applications of industrial minerals are sensitive to the hardness and abrasiveness encountered with quartz minerals, while other applications may lead to processing challenges for the end user. Therefore, process and chemistry optimization must be applied to ensure optimal grade is obtained for these valued industrial minerals. Extensive studies have been conducted in processing various industrial minerals, thus achieving a range of quality specifications, which entailed the application of ArrMaz’s CustoFloat and CustAmine collectors towards the separation of quartz from other minerals. INTRODUCTION Industrial minerals often have the misfortune of the gangue mineral being very similar in surface charge, and coordination properties, to that of the mineral of interest. An example is seen in phosphate beneficiation, when dolomite can be a gangue minerals (Table 1). Therefore, the development of processing reagents are quite complicated. Some minerals, like clays, may be washed away. However, most require the manipulation of the pH, in efforts to fine tune the system to the narrow difference in isoelectric points of the different minerals, as well as the knowledge, and resources that are necessary to exploit the differences to yield and an optimal grade/recovery. In some cases, the application of a depressant may be required, such as the phosphoric acid commonly applied to achieve the optimal balance of grade/recovery for phosphate from a mineral with elevated concentrations of dolomite (Wang, 2016), or the application of hydrofluoric acid to assist in producing feldspar product from a mineral rich in quartz (Heyes, 2012).ArrMaz's CustoFloat and CustAmine product lines have successfully been applied to the processing of industrial minerals for more than 50 years. Applications include, but not limited to phosphate, sand (glass, foundry & high purity quartz), clays (feldspar, kaolin, etc.), and many carbonaceous and sulfate minerals. The successes of these 50 years are largely due to ArrMaz's ability to tailor make the processing chemistries to fit the ever changing and declining mineral feed grade and variations in water quality (Moore, 2015; Moore, 2016). This technical knowledge of mineral processing is strongly complimented by the intimate service programs in place at many of the beneficiation plants."

Jan 1, 2018

By Andrew R. Thomas

As the demand for most industrial minerals on the world market continues to climb, educational institutions maintain traditional policy in emphasizing chiefly metallic ore deposits and energy resources in addition to the general disciplines. In spite of their increasing importance, few universities exhibit great depth with respect to industrial minerals courses due to the shortage of specialized faculty in a category this broad. As new ideas are formulated and technological advances are developed in the field of industrial minerals, the classroom still exists as a student's primary source of information. This opportunity to give today's students the benefit of modern developements has not been utilized to its utmost potential.

Jan 1, 1981

By Jingzhi Liu, Xueping Hu, Huai Wang, Simin Yang, Baoqiang Yu, Deguang Zhan

In this study, response surface methodology (RSM) and Box-Behnken design to improve copper extraction from refractory copper oxide ore were investigated. Based on single factor tests, quadratic polynomial equation to describe the relationship between influencing factors (particle size, leaching temperature, sulfuric acid concentration, leaching time) and copper leaching rate could be obtained by RSM. The optimum parameters determined by the model are as follows: particle size 64.60% − 74 μm, leaching temperature 74.15 °C, sulfuric acid concentration 0.49 mol/L, and leaching time 140.85 min. Under these conditions, experimental copper leaching rate of 85.12% could be achieved, which was very close to the predicted maximum value (85.34%) by the model, indicating the quadratic polynomial model was accurate and reliable. Copper leaching rate increased approximately by five percentage points comparing to the result of single factor tests. This study indicates that response surface methodology is an effective method to optimize experiment conditions and achieve an ideal experiment result.

Aug 17, 2022

By Georges Verly

The estimation of local recoveries is an important issue in a selective mining operation. Two techniques, probability kriging and multigaussian kriging, are applied to estimate local recoveries at Jerritt Canyon. The pros and cons of each method are discussed in light of the results. Both methods provide simple and satisfactory solutions to the problem of estimating local recoveries. Consequently, they can be useful tools to work with in a selective mining operation.

Jan 1, 1984

By James A. Finch, Xiang Zhou, Yue Hua Tan

Methods to determine frother functions, control of bubble size and froth properties, are now widely used. Some collectors also exhibit frother functions which are less understood. Using a water-air system in a mini-mechanical flotation cell setup, this paper determines bubble size and water overflow rate for three amine collectors: one primary amine (dodecylamine, DDA) and two commercial ether amines (Flotigam® EDA and Flotigam® 2835-2L) and their combination with two common frothers, MIBC (methyl isobutyl carbinol) and PPG 425 (polypropylene glycol, molecule weight 425). Compared to the frothers, the amines were less effective in reducing bubble size, giving larger minimum size and the two commercial amines showed evidence of coalescence at low concentration. In blends, at fixed frother dosage, frother eliminated the coalescence but as amine concentration increased the amines dominated bubble size. Water overflow was a strong function of reagent type. For fixed 1-cm froth depth, PPG 425, Flotigam® 2835-2L and to a lesser extent DDA produced overflow while MIBC and Flotigam® EDA did not. In blends with frother overflow increased except with Flotigam® EDA. Mechanisms are briefly explored. The principal benefit of blending identified is the elimination of coalescence if residual concentration of the two commercial amines is below ca. 10 ppm.

By Erika Moonin, Jim Nickerson, Claudio Cimiotti, Roberto Bono

"In response to the severe drought on the Colorado River basin and in order to preserve existing water capacity to the Las Vegas Valley, the Southern Nevada Water Authority contracted a new deep-water intake (Intake No. 3) located in Lake Mead. The current project (Contract No. 070F-01-C1) includes 5 km (3 miles) of tunnel with very difficult geological conditions and a 200- m (650-ft) deep shaft and marine works. This paper will present the current status of the design-build contract being constructed by Vegas Tunnel Constructors and the challenges and problems faced and the innovative solutions developed to handle the difficult conditions encountered during tunneling with up to 15 bars of pressure.ProjectbackgroundThe Las Vegas Valley receives the majority of its water from Lake Mead, which is located approximately 30 km (20 miles) east of the Las Vegas, NV metropolitan area. Due to the severe drought that has hit the southwest region of the United States, the water level in Lake Mead has receded from its high water level of 372 m (1,221 ft) above mean sea level (amsl) to a low of 330 m (1,076 ft) amsl in June 2015. Should the lake level continue to fall, at elevation 320 m (1,050 ft) amsl, the current water intakes will not be able to draw enough water to meet the needs of the local area. The risk of losing water capacity has prompted the construction of a new deeper intake. Not only is the new Intake No. 3 situated at a lower elevation in the lake at 262 m (860 ft) amsl, the new Intake No. 3 is also located to draw better quality (Fig. 1).Project challengesThe project has had several difficult challenges to overcome:• The work consisted of a 1.2 kt (1,300 st) structure constructed on a barge and lowered 100 m (330 ft) into Lake Mead anchored with 9,200 m3 (12,200 cu yd) of tremie concrete.• The drill-and-blast starter tunnel was impacted by three inflow events, resulting in a one-year project delay.• One of the main challenges was selecting the tunnel boring machine (TBM) and excavating the tunnel with expected hydraulic head pressure of as much as 17 bar (16 bar was the highest pressure recorded during the drive), crossing faulted areas, low rock cover and the risk of tunnel instability due to direct connection with the lake.• Extensive pre-excavation grouting with a constant head pressure ranging from 12 bar to 15 bar.• Structural repair of the cutterhead in difficult hydrogeological conditions [water inflow of approx. 800 m3/hr (4,000 gpm)].• Complete repair of the cascade sealing system for the main bearing and two replacements of the pinion bearings.• The TBM approach to the intake structure."

Jan 1, 2015

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 Fangyu Liu

In the grand tapestry of scientific inquiry, there are individuals whose contributions resonate far beyond the confines of laboratories and lecture halls. It is with profound admiration and respect that we present this special collection of Mining, Metallurgy & Exploration, dedicated to celebrating the remarkable career of Dr. Patrick Taylor. Dr. Taylor, recently retired from the Colorado School of Mines as the Emeritus Ansell Distinguished Professor of Chemical Engineering, possesses over 45 years of expertise in mineral processing and extractive metallurgy. His remarkable journey has seen him traversing the globe, from Canada to Egypt, contributing to pyrometallurgy, hydrometallurgy, and mineral processing. Dr. Taylor’s portfolio encompasses lab work, pilot-plant projects, research, and process development across various metals, with an impressive array of authored papers, presentations, and nine patents to his name. A soughtafter consultant for over 20 companies and an esteemed expert witness, Dr. Taylor also led the Kroll Institute for Extractive Metallurgy at Colorado School of Mines. Under his guidance, more than 100 graduate students and post-docs have undertaken transformative research, while Dr. Taylor’s 45-year tenure as a university lecturer and the creation of 10 industryfocused short courses underscore his dedication to knowledge dissemination. His contributions extend to crafting professional engineering exam questions for a quarter-century and active participation in esteemed organizations like SME, TMS, ASM, and MMSA.

Sep 16, 2023

By Ashish Ranjan Kumar, Barbara Arnold, Luis Sanchez Gonzalez

Mining operations adopt a variety of measures to combat dust underground. These include ventilation systems, water sprays, physical barriers, and personal protective equipment (PPE). Respirators are a class of PPE that can provide clean particulate- free air to the users. Powered Air-Purifying Respirators (PAPRs), used commonly in medical and other sectors, are not prevalent in the mining industry. PAPRs use P100 filters that have 99.97% dust capture efficiency. We present our results from computational fluid dynamics (CFD) simulations performed to understand the impact of a PAPR on airflow and dust particle concentration in the vicinity of a miner. These results show that donning PAPRs can lower the miners’ exposure to respirable coal dust in their workplace.

Feb 1, 2025

By A. A. Schweizer

Buckhorn ore is hydrous, argillized basaltic andesite, and is at least 60% clay composed of kaolinite and subordinate montmorillonite. Moisture content runs from 10% to 25%. The original crushing plant was a typical compression type, employing a jaw crusher, and two cone crushers. The system was plagued with constant plugging and unable to meet production plans. The three compression crushers were replaced with a Stamler Feeder Breaker followed by a Hazemag Impactor. Production plans are now exceeded. Agglomeration has progressed from an agglomeration drum to cascading conveyors, to introduction of the lime and cement into the primary crusher.

Jan 1, 1987

By P. E. Damon

An arsenal of isotopic techniques is avail-able that can date the full range of hydrothermal ore deposits. The following are prerequisites for ideal results: (1) Careful collection of samples that are related to the event in a field and process context; (2) Optical examination of the component selected for dating to be sure that it has not been altered; (3) Careful preparation of a pure component of the sample selected for dating; (4) Precise and accurate measurement; (5) Knowledgeable interpretation of the data with reference to decay systematics, properties of the component analyzed as well as the field context and thermochemical environment of the ore process.

Jan 1, 1992

By Jorge Armstrong, Sean Warren, JOSEF BOURGEOIS

The application of statistical analysis software programs has proven useful for the investigation of rockfall runout distance along a designed slope. Rockfall modeling programs are continually being upgraded with more sophisticated analysis tools, such as the use of the rigid body versus lump mass models. Engineers at mine sites utilizing the software may have varied experience related to these models, their associated input parameters, and how to interpret the generated results. To address this concern, researchers at the Spokane Mining Research Division (SMRD) of the US National Institute for Occupational Safety and Health (NIOSH) investigated the influence of slope height, slope angle, slope material, and rock size for both rigid body and lump mass models in a 2-D statistical analysis program. Based on a literature search and industry input, specific ranges common to that of an open pit mining environment were chosen for each of the input parameters to determine 90% rock runout distance as well as their sensitivity to change. Data collected from this numerical analysis and simulation will be compared to empirical rockfall data gathered through the duration of the Highwall Safety project conducted by NIOSH from 2022–2026.

Jun 18, 2023

By Donald E. Scheck

Blasting practices based on sound engineering principles are well established but the successful application of these practices requires accurate information about the overburden geology and close supervision of the drilling and blasting operations. Good design alone is not sufficient to insure good results, but the process may be difficult to control unless steps are taken to measure the variables and to provide management and the operators with the information they need to establish and maintain control. Satisfactory blasting can be defined as loosening and fragmenting the rock so that it can be handled by the excavating equipment, while at the same time, governmental regulations on air blast and ground vibrations are not violated. Optimum practices achieve these objectives at the lowest combined cost of the drilling and loading operations and the blasting materials. Total system optimization, that is, taking into consideration the effect of fragmentation on the cost of operating and maintaining excavating equipment as well as drilling and blasting costs, probably is not a reasonable goal at the present time.

Jan 1, 1984

By Kwangmin Kim, Junnhyeok Park, Taehee Lee, Minkyu Kim

Mine tailings storage facilities (TSFs) can be a significant source of fine, respirable dust. This dust poses concerns, especially for nearby communities, because of its detrimental impact on respiratory health. To address these concerns, this study examined the effectiveness of commercially available polymers, known for their biocompatible and environmentally friendly features, to prevent dust generation from upstream-type TSFs in active mining operations. It focused on two areas in TSFs: the tailings beach and slope/dike surfaces. Two types of polymers—polyethylene glycol and poloxamer—were selected, and their effectiveness was evaluated in a series of phased laboratory and field tests. The lab tests investigated the moisture-retention capacity of the tailings after treatment with the polymer solutions as well as the ability of these solutions to reduce dust emissions. Polymers were applied to a tailings bed surface in the lab and dust was generated from this surface using a wind tunnel. PM10 and PM2.5 concentrations were measured using laser-diffraction dust sensors, and the polymers were found to have reduced dust emissions up to 95%. Small-scale wind-blowing tests were conducted in the field (specifically, in a controlled environment at a TSF) to evaluate polymer effectiveness on the tailings beach and slope/dike areas. The tests revealed that the AP could efficiently suppress approximately 80% of PM10 and PM2.5 dust emissions at both types of areas. Finally, 1000 gallons of AP solution were discharged at the top of tailings beach and slope/dike areas, respectively, and found to be effective. The results of these tests showed the high potential of the biocompatible polymers to be a feasible solution for reducing the respirable dust emissions from upstream TSFs in arid and semi-arid regions.

By Irina Chernyshova, Erik Larsen, Hanumantha Rao Kota, Vladislav Slabov, Garima Jain

The separation of fine mineral particles, especially using environmentally friendly approaches, is one of the main problems in the processing of low-grade ores and the re-processing of mining tailings. This work assesses the potential of biosurfactants as collectors in the flotation of ultrafine (smaller than 20 μm) particles of hematite and malachite. As biosurfactants, we test acetylated acidic (ac-ASL) and lactonic sophorolipids (ac-LSL). In addition, n-dodecyl-β-D-maltoside (DDM) is used as a model non-ionic alkyl disaccharide surfactant, and sodium oleate (NaOl) is used as a reference. The biosurfactants are characterized using surface tension and foam analysis. The interaction of the minerals with the surfactants is characterized using zeta potential, solubility, and single-mineral flotation. The collecting properties of the surfactants are compared for the ultrafine (− 20 μm) and coarser (38–90 μm) particle size in the two-mineral flotation of hematite and malachite against quartz. The ultrafine particle size improves the grade in the oleate flotation of hematite, as well as the grades in the DDM flotation of hematite and malachite, which is explained by the weak interactions of the metal oxides with fatty acids and DDM. At the same time, the flotation with ac-LSL and ac-ASL is highly tolerant to the ultrafine particle size. These results indicate that biosurfactants are an interesting alternative to conventional petroleum-based surfactants in the flotation of Fe and Cu oxides. Moreover, a proper selection of surfactants can help combat the problem of fines.

Feb 23, 2023

By g. Caproni

The main constituent of the feed to the "Sulphide Section" (31 t/h), in the F. Sartori Plant (6000 tid) of the Miniere di Mon)eponi(Sardinia), is the ore of the Campo Pisano -Funtanaperda Mine (1 ? Difficulties have always been experienced in the treatment of this ore, owing to the extramely fine Pyrite-Sphalerite intergrowth and to the high Pyrite and soluble salts contents. The first mentioned difficulty was overcome with a rather complex flowsheet (see fig.1A and lB)(2); the others with a reagent combination that required a pH of 11 in a pulp loaded with soluble salts. This meant high consumption of alkalizer, and also of the other reagents; furthermore the alkalizer had to be mainly NaOH with only minor amounts of lime, because the latter tended to depress not only the pyrite but also the middlings, which were supposed to float. With dialchylditiophosphate alone as a collector, a lower pH could have been used, but a certain amount of amylxanthate was indispensable to promote flotation of the middlings. On the other hand, a bulk-flotation of sphalerite and pyrite at low pH could not be very advantageous on account of the high pyrite content in the feed(3).

Jan 1, 1971

By Thomas P. Oxford

The impact of recent legislation on Florida phosphate industry operations has been dramatic. The most significant influences are described: the National Environmental Policy Act of 1969; the Federal Water Pollution Control Act Amendments of 1972; and implementation of the Florida Environmental Land and Water Management Act of 1972. Further discussion includes: critical examination of the recently completed EPA Areawide EIS; potential effects of the Resource Conservation and Recovery Act of 1976; the Surface Mining Control and Reclamation Act of 1977; current local and state laws; and summary of studies on radiochemical effects of mining, seepage from gypsum ponds, and dewatering of waste clays.

Jan 1, 1979