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By S. S. SHINDE, P. C. JIKAR, N. B. DHOKEY

Mill scale is an oxide waste product of the steel mills, which contains around 70% iron and other allied impurities. In the present context, a dynamic prototype counter current reactor (CCR) has been used for experimentation and simulation of particle bed by using discrete element method (DEM). Mill scale was pulverized to ASTM mesh range 140 (106 μm)/ + 270 (53 μm), and then it was oxidized in CCR to make single oxide Fe2O3 phase by maintaining required thermodynamic conditions such as pure oxygen at 1100 °C. Then this oxidized powder was subjected to reduction reaction in CCR having gas mixture ( H2:N2) ratio of 1:4 at 875 ± 5 °C for filling degree (fd) and reactor revolution (ω) ranging from 5.38 to 16.14% and 2 to 5 rpm, respectively. A creeping fluid flow condition (Re ˂ 1) and natural heat convection (Gr/Re2 ˃˃ 1) has been maintained while undergoing solid–gas reaction. Besides particle bed behavior has been quantified by Froude number (Fr) for the optimum operating window. The simulation was validated by the experimental results of reactor reaction product by X-ray diffraction (XRD) and scanning electron microscope (SEM) images. Prevailing heat transfer mechanism and reduction reaction mechanism has been established for solid–gas counter current conditions.

Nov 22, 2021

Satisfactory means of managing growth in boom towns is a concern in mineral, energy and other large industrial developments. This session will include examinations of socioeconomic impacts, major issues such as social disruption, case studies, methods of managing growth, and concerns involving Indian lands. Innovative methods will be offered to assist the public, government, and industry in finding solutions to managing growth in rapidly growing communities.

Jan 1, 1979

By J. O. Marsden, M. M. Botz

"Heap leaching is responsible for approximately 21 percent — 3.9 million metric tonnes — of copper production and 9 percent — 270 metric tonnes or 8.7 million ounces — of gold production worldwide. Given metal price assumptions of $2.25/lb for copper and $1,250/oz for gold, these portions of global production generate revenues of $19 billion and $11 billion, respectively. For heap leaching operations, small changes in metal extraction efficiency drive substantial changes in operating cash flow margins and affect project viability. Variances in actual metal production from budgetary forecast estimates can mean the difference between success (value creation) and failure (value destruction) for a heap leach project. Despite the importance of heap leaching for copper, gold and silver production worldwide, there are no clear standards or guidelines for developing heap leach metal production forecasts. There is considerable variation among copper and gold producers that apply heap leaching technology as to how such modeling and forecasting is applied at the operational level. There are a variety of different modeling approaches that can be utilized for this purpose. However, these vary in cost, complexity, time to implement, accuracy and credibility. This paper explores the options available for heap leach modeling, discusses the advantages and disadvantages of each approach, and provides guidelines/recommendations for an effective approach to modeling metal production at existing or planned heap leach operations. The paper also provides expected ranges of variation between actual and modeled production.Introduction and backgroundHeap leaching is fundamentally different from other methods used in the processing and extraction of gold, silver, and copper and other base metals. Considered globally, the technique represents a relatively modest portion of production compared with the primary technologies applied for copper and gold recovery. Approximately 21 percent of copper production is attributable to heap leaching techniques, as opposed to 79 percent by conventional crushing, milling, flotation, smelting and refining. For gold, about 9 percent of global production is obtained from heap leaching, compared with over 90 percent by various combinations of crushing, milling, gravity concentration, flotation and/or agitated cyanide leaching processes or, in the case of placer deposits, by direct gravity concentration and/or amalgamation. In cases where heap leaching is the primary source of metal production, the ability to accurately forecast metal production may be the difference between commercial success and failure for a project or operation. Heap leaching — of crushed or run-of-mine ore — is also commonly applied as a secondary process to treat lower-grade ores from a given deposit, such as at Chuquicamata in Chile, Cerro Verde in Peru and Bagdad in Arizona for copper extraction and at Twin Creeks and Carlin, both in Nevada, for gold. In such cases, heap leaching provides incremental revenue to supplement the primary process. Variances between actual and forecast metal production from heap leaching as a secondary process are typically tolerated and absorbed within the overall site metallurgical balance. In either case, accurate production modeling and forecasting creates significant value for heap leaching projects, is essential for managing production expectations — timing and volumes — and is likely to be a critical success factor for most heap leach projects."

Jan 1, 2017

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 William A. Riggs

Salt, a non-metallic mineral whose use dates back to earliest history of mankind, and whose uses cover the widest range for any mineral raw material, is generally of widespread occurrence in commercially recoverable quantities in the oceans, in certain sedimentary rocks, in certain lakes, and in certain underground waters. Passing over geological detail, it may be said that, generally, all of the salt in the world has, at least once in geological history, been in solution in the oceans. The total salt content of today's oceans, said to equal 4.5 million cubic miles of rock salt, dwarfs the tremendous volume of salt in the sedimentary rocks. In 1958, United States production of salt was about 22 million net tons and world production about 82 million. About 3 percent of United States production is table salt, with chemical, municipal, industrial and agricultural uses taking the remainder. Mississippi River. Figure 1 has been expanded sufficiently to show also those salt occurrences and producing points which might economically ship salt into these states. Although widespread in occurrence, salt deposits and possible production areas generally show very sharp local boundaries. Salt-for non-table use is susceptible to ?place value?, a common problem in low valued raw materials, where transportation costs often exceed the value of the material f.o.b. the production point. Generally only large capacity mechanized salt producing operations can compete in United States markets, as contrasted to the many small local salt evaporators in less industrialized Mexico.

Jan 1, 1962

By David L. Giles

The alkalic igneous province of Montana consists of centers of laccolithic and stock-like intrusive complexes with associated sills, dikes, and breccia pipes (e.g., Judith, Highwood, Little Belt Mts.); isolated plug-like mafic bodies (e.g., Smokey and Eagle Buttes); and clusters of kimberlitic diatremes and ultrabasic dike swarms (Missouri River Breaks). The province extends in a belt throughout central Montana from the North Absaroka Range in the south to the Sweetgrass Hills on the Canadian border. Intrusive activity ranged in age from Late Cretaceous to late Miocene, peaking at about 50 m.y, ago. Diverse types of significant epithermal gold mineralization occur at many of the laccolithic centers. This mineralization took place in large part during the waning stages of, or following, igneous activity. Large remnant travertine blankets in the region attest to comparatively recent hydrothermal activity. The quartz-pyrite-gold mineralization ranges from igneous- hosted stockworks or fracture sets (Zortman-Landusky and Neihart districts) and breccia pipes (North Moccasin Mts.) to replacement zones in flanking and upwarped Madison Group limestone (Gilt Edge and Kendall districts). The latter are mostly localized by intraformational solution breccias in the upper Madison, notably near porphyry contacts. Gold mineralization in the province was accompanied by varying amounts of silver, base metals, sulfosalts, and tellurides, with quartz, fluorite, carbonate, and barite and gangue. Gold occurs as auriferous pyrite, sylvanite, or in native form. Since the 1880's, primary gold production from numerous scattered deposits in the Judith, Moccasin, and Little Rocky Mountains, along with byproduct gold from the Neihart silver district (Little Belt Mountain), has totalled around 2 million oz. The major deposits were in the 1-2 million ton range at an average gold tenor of 0.3-0.6 oz per ton. Most of the ore was mixed oxide or carbonaceous sulfide ore and was treated either by amalgamation or by roasting-cyanidation. Current activity includes heap-leach operations on bulk- tonnage low-grade (approximately 0.03 oz per ton) ores at Zortman-Landusky, and several small-scale, experimental leach or mining operations on carbonaceous replacement ores, as in the Kendall district and Spotted Horse mine. Current exploration efforts for gold are focused not only in the old established districts, but also in and around other alkalic centers, which have been unproductive to date, such as the Crazy Mountains, Sweetgrass Hills, and Bearpaw Mountains. Target concepts in these efforts are porphyry-hosted stockwork or disseminated gold ores and Carlin-type replacement lodes in the flanking Madison or other favorable carbonate units.

Jan 1, 2013

By S. Daniel Thompson

In underground coal mining, the specification and control of belt and bunker capacities are complicated by (1) stochastic and intermittent conveyor loading, (2) a limited ability to reduce surge at the mine face, and (3) occasional overlapping of loading from two or more mine faces on the conveyors. Recently, because of longwall mining and other factors, the capacity requirements of most mine conveying systems have risen substantially; as a result, efficient capacity design and control have become important mine planning issues. This paper reviews these design issues and their associated modeling procedures. Design considerations and modeling difficulties are also examined.

Jan 1, 1996

By Ashraf A. M. A. Wali

Many of the economic resources of Egypt have been recognized and exploited for thousands of years (e.g. gold and copper). Most of these minerals, particularly those from hard-rock sited deposits, are found in complex form along with other components while those present in sedimentary sequences are largely in simple compounds or as native elements. Recognition of their characteristic settings (structure, basin development, environment of formation etc.) is the main clue in predicting and locating their presence. The main economic minerals exploited in Egypt today come from sedimentary sequences and include sodium and potassium chlorides, gypsum, sulfur, and sedimentary iron ores. Large amounts of low grade sedimentary phosphates are known but are not of economic value at today's prices. Recent intensive investigation in the north-eastern Sinai (EI Arish) and along the southern coasts of the Gulf of Suez has revealed new and extensive sulfur and chloride deposits, and considerable oil and gas are now being exploited from closely related sediments. Tin is the only mineral that is produced from hard-rock sources, and gold and copper deposits are present but not of high enough grade to be economically viable. However, a significant part of Egypt has not yet been studied in enough detail to close the door on future discoveries. Another point of considerable geological interest is the presence of diverse, modern evaporitic settings, from which we may draw the analogs for many of the older gypsum, anhydrite, chloride and sulfur de-posits. In fact these analogs are so well displayed that both the Sinai and Gulf of Suez-Red Sea evaporites (Middle and Upper Miocene) can be readily compared with these modern deposits.

Jan 1, 1990

By David Atkin

This paper presents methods and results of environmental planning conducted for a proposed coal and iron ore transshipment terminal which would be located on reclaimed land west of Lisbon, Portugal. Oceanographic, navigational, marine, structural, material handling, and financial studies of the terminal were conducted along with the environmental analyses. However, because of the proximity of the terminal to heavily used recreational resources, residential areas, and biologically valuable habitat, anticipating and reducing the environmental effects of the terminal to minimum levels was a very important part of the overall project. The results of the study indicate that even the impacts associated with worst-case conditions would be acceptable because of appropriate pollution control measures and planning.

Jan 1, 1983

By K. Biswas

In general, it cannot be assumed that the strength of coal pillars remains constant over long time periods. Field observations indicate that a coal seam, especially when it contains a parting layer, deteriorates over time, reducing load-bearing capacity of the pillars. This paper discusses a unique approach to determine the time dependent strength of coal pillars in the field. Three coal pillars that were developed 5, 15 and 50 years ago were chosen for the study. Holes were drilled in coal and parting layers in each pillar and the strength profiles were determined for each hole using the Borehole Penetrometer. The strength data were treated statistically to establish time dependent strength equations for different layers. The results can be used to help estimate the loss of pillar capacity over time.

Jan 1, 1999

By J. Kretschmann, R. Amiri

"The Sangan iron-ore mines (SIOM) in Iran are located in a remote area, near the Afghanistan border. The deposit of SIOM is containing a geological resource of 1.2 billion tons of mostly magnetite with a Fe grade ranging from 27 to 61 %. The Iranian government plans a stepwise development of SIOM in cooperation with private companies to satisfy the growing demand of the Iranian steel industry. Sustainable development (SD) is an influential ethical concept in mining all around the world. However, a successful realization of a SD is not possible without a foundation on the core values and regarding the specific circumstances of the individual mining country. This paper introduces SIOM and describes SD activities undertaken during its development. From the early stages, these activities have been realized to secure the acceptance of the stakeholders in the region. To evaluate their effects, indicators could be filtered as the ones with the highest priority for the stakeholders. Moreover Islamic values and Iranian regulations and their influences on SIOM have been analyzed. Keywords: Iran, Sustainable Mining, SIOM, Evaluation, Islamic Values INTRODUCTION Mining Industry in Iran The Islamic Republic of Iran holds 68 types of minerals, including salt, sand and gravel, gypsum, chrome, lead, zinc, copper, coal, gold, iron etc., with 37 billion tons of proven reserves and more than 57 billion tons of potential reservoirs. Iran is ranked among the 15 major mineral rich countries (1). In accordance with the statistics published by Statistical Center of Iran (SCI), there were 5.316 active mines and 84.922 employees in the whole country in 2012-13 (2) and according to the statistics published by Central Bank of Iran (CBI) in 2011 the share of this sector in the Gross Domestic Product (GDP) of the country was 1.2 per cent (3). Sangan Iron Ore Mines (SIOM) The deposit of SIOM is one of the largest iron-ore deposits in Iran, also considered to be one of the Middle East’s richest deposits, which contains a total geological resource of 1.2 billion tons of mostly magnetite with a Fe grade ranging from 27 to 61%. It is located 300 km southeast from Mashhad, the capital of Khorasan-e-Razavi Province, and 18 km northeast of Sangan town, in Khaf County, at latitude N34°24’, longitude E60°16’ in the north-eastern Khorasan-e-Razavi Province, 30 km west of the Afghanistan border (4) (Figure 1). SIOM is owned by the Iranian Mines and Mining Industries Development & Renovation Organization (IMIDRO). IMIDRO intends to develop an open pit mine complex and supporting facilities in SIOM for the production of about 20 Mtpy of iron oxide concentrate and pellets in four developing phases (5)."

Jan 1, 2016

By Jieliang Wang, Shiwen Yi, Zhao Cao, Peng Zu

Bayan Obo ore contains mainly bastnaesite, monazite and associated iron, fluorite, calcite, dolomite, barite, and trace amount of columbite. Due to its complex mineral compositions and similar mineral properties, it is difficult to separate and obtain rare earth and fluorite concentrates with high purity by conventional magnetic separation and flotation. In this paper, a stepwise magnetic separation process comprised of wet permanent magnetic separation (PMS), wet electromagnetic separation (EMS), and superconducting magnetic separation (SCMS) was proposed to pre-concentrate iron, rare earth, and fluorite minerals from Bayan Obo ore. The results showed that iron, rare earth, and fluorite preconcentrates with high purity and low impurity content could be achieved, which might be helpful to shorten the technological process and improve the separation efficiency for the subsequent flotation of iron, rare earth, and fluorite minerals.

Sep 15, 2020

By Carrie Smith

This fall, the Society for Mining, Metallurgy & Exploration (SME) will begin a new chapter by welcoming its new executive director and chief executive officer (CEO). Melissa Russell, a successful nonprofit executive with more than 30 years of experience in global association management, officially stepped into the role on Sept. 29, 2025. She succeeds longtime CEO Dave Kanagy, CAE, who is retiring in March 2026 after more than two decades of transformative leadership. “I am honored to begin this new chapter with SME and inspired by the vital role this community plays in shaping our world,” said Russell. “I look forward to listening, learning and working alongside this remarkable group of professionals to advance innovation, champion sustainability and create a brilliant future together.” Russell brings a deep portfolio of leadership experience in technical and industrial associations to SME. Most recently, she served as executive director of the Institute of Electrical and Electronics Engineers (IEEE) Computer Society, the largest of the IEEE’s 39 societies, with more than 50,000 members across 150 countries. During her tenure, she strengthened global engagement, advanced financial sustainability and launched strategic humanitarian initiatives.

Oct 1, 2025

By T. J. Lutz, L. Yan, J. R. Srednicki, J. A. Yonkey, G. T. Homce

"Federal regulations require the installation of refuge alternatives (RAs) in underground coal mines. Of the in-use RAs, over 95% are mobile RAs with the remainder being built-in-place (BIP) RAs. Heat/humidity buildup has been one of the major concerns with mobile RAs. For BIP RAs, however, there is a lack of in-mine heat/humidity test data to determine the extent of heat and humidity buildup. To quantify heat/humidity buildup in BIP RAs, the National Institute for Occupational Safety and Health (NIOSH) performed a series of heat/humidity tests on a 60-person BIP RA with and without a borehole air supply. At various times during the year, tests were performed with cooled, heated, or unconditioned borehole air to examine how various outdoor temperatures may affect the thermal conditions inside a BIP RA. The results show that the air supplied to a BIP RA may require heating and cooling, depending on the outside air temperatures and the temperature of the mine. For example, during tests with an external ambient temperature above 70°F and a humidity that reached 90 %RH, providing 55°F dew point air was able to keep the internal apparent temperature below the mandated 95°F. Results for each test case are presented. INTRODUCTION The Mine Safety and Health Administration (MSHA) has required the installation of refuge alternatives (RAs) in underground coal mines since 2008 [1]. MSHA requires that RAs provide an environment with breathable air for entrapped miners for a 96-hour period. Heat buildup inside an occupied RA is a serious concern. Without a means to dissipate the heat and humidity generated by the occupants and the carbon dioxide scrubbing system, the temperature and humidity inside RAs could lead to severe discomfort or heat stress depending on the mine ambient temperature before and during occupation of the RA. In its 2006 report, the West Virginia Mine Safety Technology Task Force recommended an apparent temperature limit of 95°F for RAs [2]. In 30 CFR 7.504, MSHA specifies a maximum apparent temperature of 95°F inside an occupied RA [3]. The apparent temperature is calculated using both air temperature and relative humidity [4]. To determine if their RAs meet the apparent temperature limit, RA manufacturers have been performing 96-hour-long heat and humidity tests in laboratories. During these tests, a heat input of 117 W (400 BTU/hr) per person is used to represent the metabolic heat of a single miner [2]. The heat generated by the RA’s carbon dioxide system is also accounted for in testing. To account for this heat, 50 W (170 BTU/hr) of heat per miner is used for a lithium hydroxide scrubbing system, or 30 W (100 BTU/hr) of heat per miner is used for a soda lime scrubbing system [5]. In these tests, air velocities around the RA are minimized to represent the worst-case scenario of an interruption in mine ventilation that might occur in a mine disaster."

Jan 1, 2017

By R. L. Loofbourow

The Sunro Copper Mine is near the south coast of Vancouver Island about 35 miles west of Victoria. Failure of the roof of a large open stope let a good sized mountain stream into the mine. Broken are, boulders and sand were washed into the underground mill and out through a 7 800-foot adit. The adit became plugged; water burst out an a ridge above the adit, washing out the portal and o trestle by which it was reached, Rock and ore are strong but several systems of steep, pronounced but generally tight fractures are found on and parallel to the walls of the orebody. The stope was started from a slusher drift 390 feet below the bed of the River and brought up to an elevation 155 feet below the River by blasting vertical and horizontal rings of longholes in the nearly vertical orebody. Mining was stopped there and five months were given to grouting and bolting the pillar under the bed of the River, During this time and for several months thereafter sloughing increased the width, length and height of the stope. At the last known observation the stope was 77 to 96 feet wide, 185 feet long and the highest point of the domed back was only 55 feet below the River. The flooding took no lives. In other respects, however, it might be difficult to find in mining lore o more savage example of the application of "Murphy's Laws".

Jan 1, 1968

By G. M. Rao

It has been a universal observation that rich grades of ores and minerals are getting depleted, simultaneously the demands for civilization are ever increasing coupled with occurrence of poor grades of ores and minerals posing a problem to the processing engineers. At the same time, the cost of mining and milling are increasing, creating a situation where the management has to handle and process low grade ores at an economic level keeping environmental stipulations and control to be safeguarded which has been an additional cost for the management to comply with.

Jan 1, 1994

By R. Wild

[When a blast furnace has a certain defined burden and is operated under fixed conditions of blast temperature, etc., the fuel efficiency is determined by the extent to which the reducing gases can remove oxygen from the burden in the furnace stack. This is determined by two distinct factors: 1) The uniformity of gas-solid contact, and 2) The ease with which oxygen can be removed from individual pieces of burden. This latter is often called burden reducibility. When burdens were poorly prepared the first factor was by far the most important and a study of the reducibility of individual lumps was of rather academic interest recent years good burden preparation with emphasis on sized material has led to greatly improved gas distribution in the stack, and thus the second factor has become much more important and there has been a marked increase in interest in methods of measuring reducibility.]

Jan 1, 1964

By Isabel F. Barton, Matthew J. Gabriel, CARSON ROBERTS, JOHN LYONS-BARAL, LEON DUPLESSIS, Mark D. Barton

Geometallurgical assessment of orebodies in the mining industry typically relies on bench-scale or lab-based characterization techniques. In this study, we investigate drone- and tripod-based field hyperspectral imaging as a potential addition to the geometallurgy toolkit in multiple applications. This pilot study tests hyperspectral imaging for largescale mineral mapping in and around the active Lisbon Valley copper mine, including natural exposures, previously producing U-V mines, highwalls, dumps, and leaching sites. Tests include different (supervised and unsupervised) mineral data classification methods, varying mineral spectral reference libraries, comparison with ground-truth geological and spectroscopic mapping and sampling, and integration with LiDAR data. The results show that hyperspectral scans can produce spatially registered maps of the distribution of different spectrally active mineral types over dumps, highwalls, leach pads, and natural outcrops. Clays, other phyllosilicates, carbonates, and sulfates showed up particularly well. The sensor was also able to distinguish dry from lixiviant-saturated areas and map different clay types on the leach pads, and shows promise for differentiating types and health of vegetation. These results suggest that hyperspectral imaging, if coupled with robust ground-truthing, can be a useful complement to existing geometallurgical techniques in the mining industry, such as geological mapping, blast hole sampling and automated mineralogy identifications, and handheld spectrometry. In particular, hyperspectral imaging has promise for mapping the distribution of acid-consuming minerals; mapping the distribution of swelling, sliming, and heap-blinding clays; and pinpointing problem areas on heap leach pad surfaces.

Feb 10, 2021

By V. Rajaram

A mine fire or roof collapse may necessitate the reversal of main fans to isolate the fire or provide an escapeway. Hence, to assist the mine operator in estimating the flow and pressure during reversal, Engineers International, Inc. conducted a laboratory and field study of the reverse performance characteristics of main mine fans. Laboratory tests were performed using a 96-inch (2.4 m) diameter vane axial fan to establish the forward and reverse performance characteristics under controlled conditions. Subsequently, a field test was conducted in a Colorado oil shale mine during which two 79-inch (2 m) diameter fans were reversed. The data obtained indicate that reverse performance characteristics are dependent upon the blade angle and the hub to tip ratio. The quantity in the reverse mode ranged from 30 to 65% less than in the forward mode, and the static pressure was directly proportional to the square of the quantity.

Jan 1, 1985

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