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By C. K. Arthur, N. K. Dumakor-Dupey, B. A. Kansake, F. A. Kaba

Autonomous mining systems have been deployed for improving mine performance. However, there is a fear of job losses. Adoption of autonomous systems is envisaged to be resisted by major stakeholders in Ghana due to high illiteracy and unemployment. This paper assesses the preparedness of Ghanaian mining stakeholders for the adoption of autonomous systems to Ghana’s surface mining industry. Closed and open-ended questionnaires were administered to mine stakeholders. Respondents generally expressed unwillingness to accept autonomous systems into Ghanaian mines due to fear of increased unemployment. We propose setting up a mining education fund (MEF) for training stakeholders in autonomous mining systems. INTRODUCTION Mining contributes enormously to the sustenance and growth of global and national economies through the provision of raw materials, employment, revenues and foreign exchange (Carvalho, 2017; ICMM, 2017; Cordes et al., 2016; Solomon et al., 2008; Walser, 2000). The International Council on Mining & Metals (ICMM, 2014) reported that globally, formal mining employs approximately 2.5 million people. Many resource-rich countries, especially the developing ones, have experienced strong socioeconomic growth propelled by the discovery and extraction of valuable minerals. McMahon and Moreira (2014) reported a positive linkage between mining and sustainable development. They revealed that averagely, resource-rich countries have improved Human Development Index (HDI) scores than countries without mineral resources. Mining remains a crucial industry in Ghana’s economic development (Bermúdez-Lugo, 2016; Amponsah-Tawiah and Dartey-Baah, 2011). Over the years, mining has contributed significantly to the gross domestic product (GDP) of Ghana. In 2013, mining accounted for 1.7% of Ghana’s GDP and about 19% of government revenues (Ghana Chamber of Mines, 2015). The Ghana Chamber of Mines also reported that mining contributed over 50% of foreign direct investment, 37% of export earnings and 1.1% of direct employment revenues. The US Department of Energy (DOE) estimates that 65% of coal, 92% of metals and 96% of industrial minerals are mined using surface mining methods (DOE, 2007). Generally, mining is a capital-intensive venture, with high operating cost, hence there is a constant demand for mining companies to seek efficient cost reduction and production maximization strategies. One strategy being pursued keenly is automation, which is noted to improve productivity, and worker safety at minimal cost. According to Parreira (2013), mining automation involves direct teleoperation whereby workers remotely control the mining process using computers from a control room.

Jan 1, 2019

By Collon C. Kennedy, Frances C. Hartogh, C. Joel Casburn

INTRODUCTION During the nineteenth century, the federal mining law was enacted with the objective of promoting the development of the western United States by providing unrestricted access to vast areas of federal land for mineral exploration. Prior to the advent of comprehensive federal, state and local land use plans, there was little, if any, regulation or restriction of mineral exploration activities. Today, the laissez-faire policies of the past that encouraged mineral exploration have gradually given way to the public's legitimate concerns regarding environmental protection, multiple use and planned land development. As a result, the contemporary prospector confronts a maze of statutes, ordinances and regulations with which he must comply to obtain the requisite approvals and permits before commencing mineral exploration on federal, state or private lands. This presentation will provide a broad overview of the exploration permitting process. The first section of this paper recommends certain general management practices to follow when attempting to obtain exploration permits. The second section presents two hypothetical cases, one involving a drilling program on private property in California and the other involving a drilling program and the removal of a bulk sample for metallurgical tests from federal land in Nevada. The cases are used to discuss jurisdictional issues and application of certain federal, state and county laws and regulations that pertain to mineral exploration. The final section contains a brief analysis of three important recent United States Supreme Court decisions. These decisions address the scope of the federal pre-emption doctrine as it applies to activities conducted on unpatented mining claims and the constitutional limits of permissible state and local land use and zoning regulations. PERMITTING PRACTICES The environmental impacts associated with mineral exploration generally result from the construction of drill sites, roads or trenches. Consequently, after the regulatory authority has considered the issues of permissible land use, the primary emphasis of the permitting process is to address problems related to pre-construction site identification and clearance, and post-construction site reclamation. The approaches taken to address these and other related issues vary with the scope of proposed work, the site, the appli-

Jan 1, 1987

By Eric R. Braun

Ore reserves in the Republic mining district were nearly exhausted in 1984 when hole D-54 intersected a vein twenty- eight feet in drill width averaging 1.57 opt gold and 11.95 opt silver below post-mineral lake beds. The discovery area, termed "Golden Promise", has announced proven and probable ore reserves of approximately 372,000 tons averaging 1.0 opt gold and 4.5 opt silver, and drilling indicates another 756,000 tons of mineralized material containing 0.37 opt gold and 1.4 opt silver (Hecla fourth quarter 1986 report). This paper describes new geological interpretations made as part of a district research study sponsored by Hecla Mining Co., which led to the D-54 discovery. Important new geological concepts include: 1) re-interpretation of the volcanic stratigraphy of the district and recognition of a suite of pyroclastic rocks that are unique to the Republic graben, 2) identification of disseminated subaerial mineralization at a paleosurface that corresponds to the newly described upper contact of the Sanpoil Volcanics, 3) recognition that epithermal veins have a maximum productive vertical range of 0-500 meters, measured from the paleosurface, and 4) veins exhibit visual and geochemical vertical zoning within the productive zone with highest gold occurring at an optimal depth, which is interpreted as the average depth of hydrothermal boiling.

Jan 1, 1987

By Rongjie Kong, Shiwei Wang, Dongjiao Gui

Metal cations have significant effects on the flotation of coal and minerals. In this study, the effects of monovalent cations ( Na+ and K+) on the flotation of low-rank coal (LRC) were investigated using flotation and particle–bubble attachment experiments and through X-ray photoelectron spectroscopy (XPS) and molecular dynamics simulations. Oleic acid (OA), methyl linoleate (ML), hexadecyltrimethylammonium chloride (CTAC), ricinoleic acid (RA), and kerosene were used as flotation collectors. The flotation experiments revealed that the flotation yields of LRC improved when OA, ML, RA, CTAC, and kerosene were used in pure deionized water. However, flotation was suppressed for these collectors in the presence of K+ and Na+ ions. In contrast, when using CTAC, the flotation yield increased in the presence of these ions. Specifically, the flotation yield increased from 41.24 to 87.03% when 2.0 kg/t CTAC was used in 10 mmol/L NaCl solution. Particle–bubble adhesion experiments and XPS revealed that the hydrophilic groups of CTAC were adsorbed on the LRC surfaces by electrostatic forces, whereas the oxygen-containing functional groups of OA, ML, and RA formed hydrogen bonds with the LRC surface in pure water. Finally, the simulating result revealed that the hydrophobic ends of the OA, ML, and RA collectors hinder the flotation of LRC by adsorbing monovalent cations, whereas the adsorption of monovalent cations on the hydrophobic end of the cationic surfactant (CTAC) promotes flotation via strong electrostatic interactions.

Jan 31, 2024

By T. Y. Yan

The various ion exchange reactions occurring during the restoration of formations contaminated with ammonia during in situ uranium leaching are reviewed. Data are presented on the restoration of a previously leached laboratory packed column using line saturated brine. Although this restoration fluid selectively and effectively removed the ammonia, 24.5 pore volumes are required to reduce the ammonia concentration from 500 to 3 ppm. The presence of NaCl in the restoration fluid is beneficial in + improving the selectivity of the system for NH removal and reducing ca++ ion consumption.

Jan 1, 1982

By Homer E. Harris

As a result of the enactment of the Federal. Coal Mine Health and Safety Act of 1969 1, the Department of Health, Education, and Welfare (HEW) has been carrying out research in the "field of coal mine health". The National Institute (formerly Bureau) for Occupational Safety and Health (NIOSH) was designated the agency within HEW to be responsible for such research activities. One of the early programs sponsored by NIOSH was undertaken by Eastern Associated Coal Corp., with the Harvard University School of Public Health participating as a subcontractor to Eastern. This program on Coal Mine Respiratory Protective Devices, which started on June 30, 1970, had five major objectives as follows: a. to determine current status of respirator usage with respect to duration and frequency, types. and maintenance b. to determine acceptability ( and reasons therefor) of currently used units c. to determine protection factors provided by respirators worn by working miners d. to make recommendations on ways to improve existing units, or on research needed to develop new types of respiratory protective devices for coal miners e. to provide recommendations to mine management on more effective use of respiratory protective devices

Jan 1, 1973

By C. O. Lee

The Grand Isle Sulphur Mine is located in the Gulf of Mexico, approximately seven miles off the coast of Grand Isle, Jefferson Parish, Louisiana. The depth of water at this location is about 50 feet. The deposit is on acreage covered by oil, gas, and mineral leases which were originally issued in favor of Humble Oil & Refining Company by the State of Louisiana, and which were continued, maintained, and redesignated by the Department of the Interior of the United States, pursuant to Section 6(b) of the Outer Continental Shelf Lands Act. On September 19, 1956, Freeport Sulphur Company acquired from Humble Oil & Refining Company the sulphur rights underlying the tracts. This assignment was approved by the Secretary of the Interior on July 12, 1957. The Director, United States Geological Survey, approved Freeport Sulphur Company as Operator on July 31, 1957. Actual design began in September 1956; the first structural contract was let December 15, 1957, and offshore erection began in June 1958. The initial phase of construction will be completed and production started in early 1960. The estimated total cost of the project is $30,- 000,000, of which $8,000,000 is the extra cost for being in the Gulf of Mexico.

Jan 1, 1959

By M. Sadegh Safarzadeh, Erich U. Petersen, Jan D. Miller

"An acid bake-leach process has been identified and applied to an enargite concentrate containing ~67% enargite, ~27% pyrite (FeS2), ~3% chalcopyrite (CuFeS2), ~6% sphalerite (ZnS) and <1% galena (PbS). Sulfuric acid baking of this concentrate resulted in the transformation of the concentrate to S8, As2O3, HFe(SO4)2•4H2O, PbSO4 and Cu0.47Fe0.53SO4•H2O, all of which (except elemental sulfur and PbSO4) dissolved during the water leaching step. More than 87% Cu and 64% As were leached when the concentrate was baked at 200°C over 7 hours with a sulfuric acid-toconcentrate weight ratio of 1.6. Less than 1% As was lost to the gas phase. Upon water leaching, copper and arsenic were released to the solution at a concentration ratio of about 3:1. While enargite is very reactive during the sulfuric acid baking reaction, other minerals present in the concentrate such as pyrite, galena and sphalerite may compete to consume sulfuric acid and be converted into their corresponding sulfates at different concentrations. The purpose of this paper is to present our examination of the effects of sulfuric acid dosage on the extractions of Cu, Fe, and As from an enargite concentrate. In this regard, the concentrate, baked concentrate, and the leach residues are characterized and a conceptual process flowsheet is described for the acid bake-leach process for the treatment of enargite concentrates.IntroductionThe occurrence of enargite (Cu3AsS4) in copper ores and concentrates and the associated high arsenic values in such resources have resulted in a considerable decrease in the demand for such concentrates because they cannot be economically processed using conventional technologies such as smelting and atmospheric leaching (Mihajlovic et al., 2011). The exploitation of such problematic deposits through competitive treatment strategies will be required in the near future in order to satisfy increasing pressure from the copper market. It is expected that the average arsenic grade of copper concentrates will increase from 0.17% in 2008 to 0.22% by 2020 (Mayhew et al., 2011).The acid bake-leach process was identified and selected for further investigation at the University of Utah as a possible process alternative for the treatment of enargite concentrates. In this case, adequate amounts of concentrated sulfuric acid are mixed with the concentrate and heated to the temperature range 150-300°C. Subsequently, the baked material is leached with water/weak acid and the acid bake-leach process has some advantages over conventional sulfuric acid leaching (Prater et al., 1970). During water leaching, metal sulfates are released in solution, after which they can be extracted through well-known hydrometallurgical techniques. While the majority of the work has been done on oxide minerals, there is a limited record of sulfuric acid baking of sulfides."

Jan 1, 2015

By Jan M. Mutmansky

Since 1973 when the first edition of the SME Mining Engineering Handbook was published, many significant changes have occurred in the US mining industry. The industry went through a fairly prosperous period immediately after 1973, but then many economic pressures came to bear on mining companies, particularly in the metal and coal branches of the industry. These pressures changed both the mining methods used and the general economics of the mining methods. As a result, the industry today is different in many ways titan it was in 1973. A general summary of some of the more important changes that have come about will be provided here as well as some assessment of the effects of these changes on the choices of mining methods. In the metal mining industry, the most significant trends were increased surface mining, the use of larger and more efficient equipment, and increased technology and automation. The primary impetus for these changes was unprecedented competition from foreign producers. In many cases, this competition came about because of the nationalization of foreign mines and the tendency for these mines to become a source of foreign exchange. Under these circumstances, the mines could be operated even though they were not profitable. As a result, domestic

Jan 1, 2008

By I. R. M. Chaston

Abstract. This paper puts forward the concept of &apos;radial&apos; plant layout where all crushing, milling and treatment operations are preferably concentrated in one central area and these separate stages are connected by radiating conveyors to and from outside storage areas. This system is contrasted to the more customary system of &apos;linear&apos; plant layout where the crushing, milling and often the treatment operations follow one after the other in separate buildings. The radial system simplifies and improves contral and supervision to a very considerable extent and can lead to a form of continuous plant operation with the separate sectors shutting down in succession for necessary maintenance while maintaining the overall plant operation. The paper is illustrated with example: from past and recent diamond treatment plant practice in South Africa which demonstrate the reduction in plant labour achieved by this system. Previous objection to this type of layout on the grounds that it inhibited plant expansion are shown to be unwarranted. Radial Layout for Increased Treatment Plant Productivity A great deal of time and trouble is spent by highly qualified and experience( metallurgists in developing the right treatment process for a given ore. This process is then often expressed in a treatment flowsheet of the type shown in Fig. 1 which shows a typical diamond plant. This flowsheet, when completed, is commonly handed over to the mechanical engineers who then design the layout of the equipment indicated on the flowsheet and produce the working drawings upon which the detailed construction of the treatment plant will be based. It is an unfortunate fact that the tedious and time-consuming juggling of equipment and inter-plant transportation is often left to hard-working draughtsmen who, however capable&apos; in their field, lack practical experience in the day-to-day operation and maintenance of the treatment plants they design. As a result many plants have been produced which, while they satisfy the requirements of the flowsheet with minimum capital requirements, cost far more than should be necessary to op¬erate and maintain. It is often possible to change individual items of equipment which do not achieve the performance required of them, but it is usually extremely expensive to change the basic layout of the plant if this should be found to be unsatisfactory. It should therefore be recognised that great care and attention should be spent on consideration of the basic layout of any treatment plant and that the views of both designers and operators should be fully regarded before settling upon the inevitable compromise dictated by the varying requirements of process-engineering and economics. It is unfortunate that this important subject receives such scant regard in the standard ore dressing text books and hand-books, being usually dismissed in a few paragraphs.

Jan 1, 1977

By Kwangmin Kim, Junnhyeok Park

In the hard-rock mining industry, the generation of fines during blasting is an important issue because it has a significant effect on production processes. Although various approaches have been used to estimate fines generation in recent decades, as a practical matter, measuring the amount of fines is nearly impossible given the technical limitations and the scale of mine blasts. In this study, a dynamic PPV damagemodel was developed and applied to predict fines generation as a result of blasting. This modified version of the crushed zone model (CZM) considers dynamic rock properties and peak particle velocity (PPV), which represents the induced stress in blasting. Dynamic rock-fracturing tests were conducted using a split Hopkinson pressure bar (SHPB) to determine the parameters that represent the relationships between rock strength and strain rate as well as the relationships between fines amount and strain rate in the model. A case study was conducted that entailed determining the radius of the crushed zone for given blast designs and rock properties and then measuring the fines amount within this crushed zone. This case study indicated that the dynamic PPV model can provide a rough estimate of fines generation for given dynamic rock properties and blast design parameters and that this method has the potential to be a useful indicator, or index, of fines generation.

May 16, 2020

By Dominick Mandalari, David Mast, Heather Ullinger, Juan Granja, Amanda Foote

The City of Akron will construct the Northside Interceptor Tunnel project, a U.S. EPA/ DOJ CSO Long Term Control Plan Project. The system will provide at least 10.3 million gallons of storage in a 16.5-foot finished ID and 6,660-foot-long rock tunnel. The system will reduce both overflow volume and number of overflow structures on the Cuyahoga River. The project includes deep drop shafts and more than 3,000 linear feet of 48 to 96-inch I.D. sewers installed by trenchless construction methods. This paper will discuss the project background, ground conditions, and other challenges overcome during the design phases.

Jun 13, 2023

By Zong‑yu Li, Shao‑jian Ma, Xiao‑jing Yang, Jin‑lin Yang, Xing‑nan Huo, Heng‑jun Li

Optimizing and adjusting the particle size composition of grinding products is of great significance for improving economic benefits and resource recovery and utilization. In this study, grinding contribution and quantitative separation of impact and grinding mechanism in cylindrical mill were creatively researched, and the grinding technical efficiency of impact and grinding was coupled to the grinding technical efficiency of grinding in drop-off mode. The results showed that the contribution rate of impact and grinding in grinding in drop-off mode varied with the grinding time. On the whole, the contribution rate of impact action increases with the grinding time and gradually becomes stable, and the contribution rate of grinding effect was just the opposite. Under the experimental conditions, the main contribution of the grinding process is impact action, and the contribution of grinding action is auxiliary. In addition, the contribution rate of impact and grinding effect in grinding in drop-off mode was also related to the feed particle size. The contribution rate of impact effect decreased with the decrease of feed particle size, while the contribution rate of grinding increased inversely.

Aug 3, 2023

By S. N. Gurulaxmi, Veerendra Singh

The abstract discusses the increasing consumption of manganese ores and the need to utilize low-grade ores and rejects. The study focuses on developing a low-cost process using a cupola furnace to recover manganese values from these resources. The process involves smelting ore blends to produce high MnO slag and pig iron. The study investigates various factors to improve iron reduction and separation from MnO-bearing slag. The results show that the process can produce slag with MnO > 35% and Fe(t) < 5% using low-grade Mn ores. The process also achieves Fe reduction between 50 and 70%. The cupola furnace offers advantages like low cost and ease of operation, making it suitable for processing low-grade ores and rejects to produce synthetic MnO-enriched products for various industries.

Apr 1, 2022

Previous models describing the aggregation of polymer coated particles fail to take into account the fact that there are a limited number of sites onto which a polymer segment can adsorb, called ?active? sites. Thus, the collision efficiency is a factor not only of the fractional surface coverage, but also of the number of active sites. In this study, a physical model of the flocculation system was devised in which the number of these sites could be varied, in order to study the effect on particle aggregation.

Jan 1, 1987

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&apos;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 Kenneth S. Johnson

Oklahoma is the only; state in the nation that is currently producing iodine. The iodine is extracted from iodine-rich natural brines being pumped from deep wells drilled into Pennsylvanian sandstones in the Anadarko basin of northwestern Oklahoma. Woodward Iodine Corp., started in 1977, was the first plant in the United States built for iodine recovery since the 1930s. At present, three companies are operating four iodine-producing facilities in northwestern Oklahoma. The combined production of these facilities, 1,321,000 kg in 1997, is about 26% of the U.S. annual consumption. Iodine is present in concentrations ranging from less than 100 ppm (parts per million) to as much as 1,560 ppm in brines in various Paleozoic strata in the subsurface of northwestern Oklahoma; these concentrations are exceptionally high, and are well above those of any other known brines in the world. Strata with the highest iodine content in the area (Mississippian limestones) have low permeabilities, and thus would yield only small amounts of brine. On the other hand, the lower Morrow sandstones (Lower Pennsylvanian) have a relatively high permeability and are capable of yielding large quantities of brine that average 300-350 ppm iodine. The Morrow brine reservoir was deposited in shallow-water-marine and intertidal-shelf environments and now is buried 6,000-10,000 ft below the land surface. Production is localized to Morrow channel deposits confined to an Early Pennsylvanian paleovalley that is 1-2 mi wide, is about 70 mi long, and is referred to informally as the "Woodward trench." All three companies are producing iodine-rich brines from Morrow sandstones in three different parts of the Woodward paleovalley, and one of the companies also is extracting iodine from oil-field brines coming from several petroleum reservoirs near Dover, about 80 mi east of Woodward. The basic extraction method employed by Woodward Iodine Corp. was used in Louisiana and California operations in the late 1920s. This method is commonly called the air-stripping process. Lower Morrow brine containing dissolved sodium iodide is pumped to the plant through a series of pipelines, where by-product natural gas is separated and processed. The brine is then acidified and subsequently oxidized with chlorine to convert the iodide to iodine. The iodine is air stripped and reabsorbed with sulfur dioxide and water, converting it to hydriodic acid, or process liquor. The process liquor is then processed, using chlorine once again, to crystallize the iodine as a solid. This is then melted and frozen to form a solid product, which is packaged in 110-lb (50-kg) drums and shipped to end users throughout the world.

Jan 1, 1999

By Miklos D. G. Salamon

The laminated model, in conjunction with the seam element method, is expected to be a powerful predictor of subsidence due to coal mining. The fundamental solutions for the model are presented. Numerical approach to determine the roof-to-floor convergence and evaluation of ground movement are discussed. Numerical results and comparisons with field observations are given to illustrate the validity and the potential of the model.

Jan 1, 1986

By G. W. Luxbacher

With the advent of acid rain legislation included within the Clean Air Act Amendments of 1990, a great deal of uncertainty with regard to price, source and production quantities has been cast into the coal market. Powder River Basin and other western coals continue a rapidly accelerating migration eastward, South American coals move into the northern markets, states propose legislation to assist utilities in complying with the new regulations in hopes of maintaining their own coal industries, while some utilities question the long term availability of eastern compliance coal. Any major coal producer must make decisions now to assure their continuing presence in the market place; several companies have adopted a strategy to acquire eastern compliance reserves while others have invested in technology to compete as a low cost producer. This paper discusses some of these options in light of the uncertainties of the market place, from an eastern coal producer?s viewpoint.

Jan 1, 1992

By S. K. Kawatra

In this paper three methods of on-stream analysis 1) Radiometric techniques, 2) X-ray tube techniques and 3) Neutron activation method are reviewed. Advantages and disadvantages of each method are discussed.

Jan 1, 1984