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By J. William Ganser

This paper is one of a series being prepared by the U. S. Bureau of Mines describing mining and milling methods and costs at cement-plant quarries throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs might in many instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically palled to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of Fred Burkett, civil engineer, and F. O. Londrey, chief clerk, of the Trinity Portland Cement Co., for assistance in preparation of this paper, "The Geology of Dallas County. 1918," Bulletin 1818, Texas Geological Survey, Austin, Tex., by E. W. Shuler, was also freely consulted.

Jan 1, 1931

By H. Bouzahzah

Sulfidic tailings, subjected to atmospheric water and oxygen action, can generate acid mine drainage (AMD); which is the most important environmental problem facing the mining industry. AMD generating potential can be assessed by the static tests which consist of a screening method where the neutralization potential (NP) and the acid-generating potential (AP) of a given rock sample are determined. The AP and NP are determined separately in the different static test existing procedures which can be divided into two distinct classes: chemical and the mineralogical methods. For some chemical method, the AP is calculated on the basis of total sulfide sulfur content in the sample which may overestimate its AP if significant quantities of non-sulfide sulfur species are present (e.g. organic S in coals, some sulfate as gypsum, barite, etc.). However, the mineralogical method evaluates the AP by the sum of the individual sulfides participation on acid generation based on their concentration within the sample and can be more accurate than the chemical method. For AP calculation, the Paktunc (1999a) mineralogical static test takes into consideration all sulfide minerals occurring in the sample. However, it does not take into account the rates of acidity production of these sulfides submitted to weathering conditions. So, the present study focusses on the modification of Paktunc AP calculation by considering the acidity production rates of these minerals. To reach this objective, five base-metal sulfides (pyrite as reference, chalcopyrite, sphalerite, arsenopyrite, galena), diluted within quartz (25?75 wt.%) simulating mill tailings were subjected to a kinetic test to evaluate their AP. The results show that all the studied sulfides minerals generate acidity at different rates, so the Paktunc?s equation for AP calculation has been adapted accordingly.

Aug 1, 2013

By D. G. Hulbert

"Mineral processes are complex operations that have been modelled, controlled and simulated by diverse technologies. A review is given of some models of mineral processes in the literature. A new variation of a dynamic process model of flotation is presented. Process models, describing real and relevant physical variables, give a good understanding and good qualitative simulations, but can sometimes require prohibitively difficult and extensive parameter estimations. Process control is usually best done on operational plants by the fitting of system models, which can home in on the plant?s observability, controllability and optimisation. System models can be of a form amenable for use in appropriate techniques for controller design and implementation. The control of milling circuits is discussed in some detail. While simulators use models to predict dynamic or steady-state information, part of their strength lies in their ease of use and their ability to test different types of specifications. Some results are given for a flotation circuit simulator that can be made to solve virtually any permutation of specifications.INTRODUCTIONThe development and application of appropriate technology can lead to better operation of mineral processing plants in industry, so that substantial benefits can be obtained from improved throughputs, efficiencies and product qualities. This paper addresses some of the principles and methods used in the quest for the development and exploitation of such technology. Although the design of processes is often the motivation for modelling and simulation, this paper also targets the use of modelling and simulation for the control and optimum operation of mineral processes. The two processes given the most attention here are flotation and milling.Technologies used in mineral processing range from simple to very complex. Simple technical principles, such as mass and component balances, can yield some simple and effective strategies for modelling and control. However, minerals in particulate form have such complex physical and chemical properties that there appears no end to the complexity that emerges, as more and more factors are taken into consideration in the pursuit of better results and understanding. The situation is aggravated by the complexity of mineral processing plants, which have spatially variable conditions within process units, and complicated interactions between these units."

Jan 1, 2003

By N Weerasekara, M Bird, M Yahyaei, M M. Hilden, M S. Powell, J Franke, P Toor

The combination of new tools with a more rigorous approach to understanding the interaction of mill liners with overall mill performance and economics, forms the basis of an integrated approach to liner management. Based on accurate liner wear measurements, some (limited) physical mill inspections and surveys, accurate calibration of the mill load and analysis of process data, a whole new approach to liner selection, relining intervals and mill control is proposed. Collection and analysis of this information in operating mills illustrates the mill performance improvement which can be attained through this careful measurement and modelling approach.A more holistic approach to liner management is proposed, including a broadening of the current work to cover the potential benefits of improved relining technologies and predictive liner wear modelling. CITATION:Powell, M S, Hilden, M M, Weerasekara, N, Yahyaei, M, Toor, P, Franke, J and Bird, M, 2012. A more holistic view of mill liner management, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 95-104 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Jankola W. A, Delong O. J

Historically, the silica content of zinc concentrates treated at Cominco's Trail Operations has been low. Silica in the roaster calcine seldom exceeded 1.5 per cent because of the low silica content of concentrate from Cominco's Pine Point mine. With the shutdown of Pine Point, alternate sources of concentrate were required and it was anticipated that calcines containing greater than two per cent silica (with excursions above three per cent) would have to be treated. Previous experience indicated that the existing leaching circuit could not tolerate such high levels. Therefore, a research program was undertaken to identify the key factors affecting silica precipitation; to compare different process alternatives; and to make recommendations for modifications to the existing plant. A project to modify and upgrade the leaching circuit has now been completed. Calcines with higher silica contents are successfully treated, but the upper limit of the circuit is unknown. The results of the research work will be discussed and the new leaching plant will be described. Recent operating results will also be presented.

Jan 1, 1993

By Jonathan K. Hrica, CASSANDRA L. HOEBBEL, Jennica L. Bellanca

Accidents involving powered haulage and mobile equipment such as haul trucks often account for the greatest number of fatalities in the mining industry each year. Despite previous analyses that have identified root causes and other contributing factors, there is still a need to better understand the events leading up to these types of accidents, what lessons may be learned, and what strategies can be employed to prevent fatal accidents from occurring. This study examines Naturalistic Decision Making (NDM) using the critical decision method (CDM). The CDM is a retrospective interview approach used to explore timelimited, high-stakes, decision-making. In this study the CDM is used to obtain more information about what happens prior to, during, and after a potentially fatal situation such as a near-miss event, loss of control, or minor accident involving equipment damage. Researchers captured firsthand accounts from 21 haul truck operators involved in near-miss events from mine sites of various sizes and commodities throughout the United States. These accounts provide rich and detailed narratives from the perspective of haul truck operators themselves and reveal insights into what decisions haul truck operators make, what sensory cues they perceive, and what strategies they employ during challenging and non-routine situations. Decision-related themes that emerged from the data are presented and discussed. These results, along with potential solutions offered by study participants, can help to inform future research, raise awareness about hidden hazards, and build more creative interventions and realistic training scenarios for use by the industry to address haul truck safety issues.

Feb 1, 2024

By K. G. Philo, R. C. W. Webber-Youngman

mining, where data-driven decision making optimizes resource extraction, enhances safety, and ensures sustainability. The adoption of digital technologies like artificial intelligence (AI) and the Internet of Things has amplified the importance of digital information. However, the integrity and security of this information are paramount, leading to the exploration of blockchain technology as a potential solution for secure digital value exchange in mining. This research examines blockchain's capabilities, drawing insights from its applications in sectors like banking, government, healthcare, and entertainment, and evaluates their relevance to mining's core value chain processes. The study identifies blockchain's distributed ledger technology, cryptographic security, and decentralization as unique advantages that can revolutionize mining by enhancing transaction speed, reducing costs, and improving supply chain transparency and compliance with sustainability standards. Blockchain's transparent and auditable records can enhance business transparency, fostering trust among stakeholders, including investors and regulatory bodies. The technology's consensus mechanisms and smart contracts further promote trust in collaborative ventures. This research provides a foundational understanding for decision-makers in the mining industry to evaluate blockchain's feasibility and potential return on investment, guiding strategic planning and resource allocation for blockchain applications. By leveraging blockchain, mining companies can optimize operations, improve sustainability practices, and establish a robust foundation for future growth, positioning blockchain as a transformative technology in the sector

Jul 10, 2024

By M. J. Kovalik, D. E. Wolfson, F. Fischler

Plastometric tests were made to determine the maximum thickness of the plastic layer for different U.S. coals . The effect of test variables on the maximum thickness of the plastic layer was studied . The values for the maximum thickness of the plastic layer were found to be related to the Gieseler maximum fluidity , plastic temperature range , free swelling index , and other plastic properties of coals . Only a general relationship was observed between the plastometric parameters obtained in these tests and the coking properties of coal .

Jan 1, 1964

By Elham Kordzadeh

As the world’s reserves of coarse and high-grade iron ores continue to shrink, beneficiation is becoming increasingly important. The resulting concentrates cannot be used directly as feedstock for iron making, but require an additional agglomeration step. Pelletizing is preferred, because the uniform chemical, physical, and metallurgical characteristics of pellets make them a more desirable feed for the iron making processes. The heat hardening or induration of pellets is typically done in shaft furnaces, grate-kiln systems or on straight grates. Rotary kilns were originally developed in the late 19th century for Portland cement production [1]. The main development work for the successful adaptation of the process to the thermal treatment (induration) of green balls from iron ore was performed by Allis Chalmers in Milwaukee, Wisconsin, USA in the 1960’s [2].The straight grate process, which was first used in 1955 at Silver Bay, Minnesota, was a dedicated development with the aim to pelletize and indurate magnetite (taconite) concentrate [2]. There are various important technical and economical distinctions between the two pelletizing technologies. The most important differences include that a grate-kiln has three distinct pieces of equipment, a preheat grate, a rotary kiln and an annular cooler, whereas in the case of a straight grate, the entire indurating process is done on one piece of equipment only. In addition, both technological solutions have differences in their recuperation systems, direction of air flow in drying, number of burners, form of pellet movement, etc., which cause differences in raw material suitability, process control, economical aspects, plant operation and product pellet quality.

Oct 30, 2017

By Simón Díaz‑Quezada, Ernesto Arancibia, HUMBERTO ESTAY, Tomás Vargas

In situ leaching (ISL) is an attractive technique that enables copper recovery from copper oxide ores that are either low-grade or located at depths too great to be economically exploited through conventional methods. At present, in situ leaching (ISL) has been applied to intact copper oxide ores, in particular, those which (i) present a good natural permeability and (ii) do not require preconditioning. Many copper oxide ores present low natural permeability. These are located above the water table and need preconditioning for the ISL application. The present work shows an economic assessment of the application of ISL to this type of copper ores. The preconditioning technique considered here involves the application of partial mining by sublevel stoping by removing a small fraction of the ore. This technique results in forming an ore bed with good permeability and good solution collection at the stope base. The economic assessment of this approach suggests that it can be implemented with positive net present values to copper oxide ores located at depths in the 100–300 m range, with copper grades above 0.4%. The maximum acid consumption values are below 52.5 kg/t, with blasting procedures designed to produce an ore bed with an average particle size below 6″. The breakdown of operational costs indicates that the mining cost is still very high, accounting for up to 60% of the total operating costs. Therefore, optimizing mining procedures is still necessary for improving the economic outlook of this approach and thus expanding the application field of ISL.

Feb 4, 2023

By B. Emwanu, R. A. Raju

The implementation of new technology in mining can be likened to a paradoxical situation or dilemma, where, on one hand, major mining projects are not able to solicit investor funding unless it is proven that the business cases were developed using tried and tested mining methods. On the other hand, new and innovative mining technology and mining methods need first to demonstrate and prove themselves under real production conditions over a reasonable period before they can be considered bankable feasibility studies in the mining industry. This dilemma locks new mining technology investments in a continuous cycle of underinvestment. Technological innovations are particularly relevant to the mining industry, which deals with the challenges of depleting access to resources, requiring new solutions to remain sustainable and competitive. In the last decade, the mining industry has come to realise that technological innovations can directly contribute to its sustained competitive advantage (Sanchez, Hartlieb, 2020), helping to reduce costs, lessen environmental impact, increase production, and improve mineral recovery. While understanding barriers and drivers for technology adoption is important for the success of technology implementation efforts and the sustainability of the mining sector (Muduli et al., 2013), this paper suggests strategies to exit the dilemma, proposing a preliminary framework.

Oct 24, 2025

By Yi Luo, Jian Yang, Hua Jiang

Surface subsidence induced by underground coal mining activities, especially longwall mining operations, can cause various problems to interstate highways ranging from structural integrity, drivability to safety. Accurate subsidence prediction, correct influence assessments, and effective mitigation measures are the keys to ensure the safety of highway traffic. The surface subsidence prediction program, called comprehensive and integrated subsidence prediction model (CISPM), was developed based on the principle of influence function method and has been validated with a large number of subsidence measurements. In this paper, the techniques to use the predicted final surface movements and deformations for assessing their influence on the integrity and functionality of highway structures (e.g., road surface pavements, concrete slabs, transverse joints, etc.), vehicle dynamics, comfort level, and drivability are presented. A number of mitigation measures to protect the highway structures and to ensure traffic safety are proposed along with an application case.

By De-qing Zhu, Zi-fu Gao, Jian Pan

"In order to produce high quality metalized products and prevent from burden cohesion during pre-reduction, self-fluxed pellets were made for COREX process in the paper. The effects of reduction temperature and reducing gas composition on pre-reduction behaviors of self-fluxed pellets are studied. The results show that the prereduced pellets have poor quality and deposited carbon appears when the reduction temperature is between 600°C and 700°C. The metallization rate, reduction degree and compressive strength of prereduced pellets are promoted by the elevating reduction temperature and mole fraction of H2. Pellets reduced by pure H2 at 800°C have high metallization rate (96.2%), reduction degree (99.4%) and compressive strength (960N/pellet). In all tests, self-fluxed pellets display normal swelling (RSI<l5%) behavior which reveals that self-fluxed pellets are suitable for COREX process. Increasing reduction temperature and mole fraction ofH2 in reducing gas is benefit for pre-reduction of pellets.IntroductionCompared with Blast Furnace, the COREX process has advantages of short flow sheet, using non-coke coal and high-energy utilization. Acidic pellets and lump ores are the chief iron- bearing burden for COREX process which could lead to low melting point substance appearing in per-reduction process. In addition, the acidic hematite pellets tend to swell during the reduction [1-3]. This will result in decreasing compressive strength of pellets, burden cohesion, bad air permeability and poor work status in shaft furnace. Adding carbonate flux could restrain burden bonding to some extent in actual production, but decomposition of carbonate flux increases energy consumption. Worse still, weak reduction potential is unfavorable to iron material reduction [ 4, 5]."

Jan 1, 2013

By John G. Parker

The rare-earth elements, sometimes known as the lanthanides, comprise the series of 15 chemically similar elements with atomic numbers 57 through 71. Yttrium, with atomic number 39, is often included in the group, because its properties are similar and it more often than not occurs in association with the lanthanides. Thorium is included in this survey due to its close association with the lanthanides, particularly in the mineral monazite. The lanthanides were first recognized as elements around 1750 and were the subject of much study by chemists during the 19th century. The purely chemical methods then available failed to resolve the strange intimate relationships between these elements, and it was not until about 1920 that the full series was explained.

Jan 1, 1971

By David Bendersky

This report covers the activities of a feasibility study of fiber optics technology fur use in mines. The objective of the study was to evaluate, both technically and cost-wise, the possible use of fiber optic technology for underground mine communication and monitoring systems. The first phase of the study was devoted to the collection of information on the present underground mine communication systems and monitoring techniques, and the status of applicable fiber optic technology. In the second ph se of the study, a communication and monitoring system for a hypothetical underground coal mine was designed and the costs estimated. The significant findings and conclusions are presented.

Jan 1, 1982

By Robert S. Schechter

This report describes the development and application of PHASEQ/FLOW, a geochemical flow simulator capable of describing the dynamic changes in chemical composition of an aqueous solution during flow in a permeable medium. The solution components can react through intraaqueous reactions, redox, precipitation, or dissolution. The assumption of local thermodynamic equilibrium ensures maximum generality with respect to the number of species and components possible; however, the fluid flow itself is limited to one-dimension. The report describes several applications: generic batch equilibria, flowing equilibria, uranium roll-front deposition, and roll-front leaching.

Jan 1, 1985

By W. A. Grosh

Records show that much of the lead produced in the Upper Mississippi Valley lead-zinc field was taken from natural openings along crevice systems at shallow horizons or at the surface. During the early history of the district, the shallow deposits were worked intensively; but in recent years the production of lead, except as a byproduct of deeper mining for zinc ores, has not been significant. Considering the methods of early mining, the character of mineralization, and the fact that galena can still be found on the surface of the old digging areas, it was reasoned that enough mineralization might remain on and above bedrock to permit, through the use of modern equipment and methods, economical re-treatment of surface material in the digging areas.

Jan 1, 1960

By A. D. Marcy

The Midnite Mine is an inactive, hard-rock uranium mine in Stevens County, WA. Oxidation of sulfide-containing minerals, primarily pyrite, in the ore body produces large quantities of acidic water. An interception system installed by the mining company limits the discharge of contaminated water from the mine. The U.S. Bureau of Indian Affairs (BIA) and the U.S. Bureau of Land Management (BLM) have been actively involved in planning remediation of the disturbed areas. To assist in remediation, the U.S. Bureau of Mines (USBM) initiated research to determine water quality and to define ground water flow characteristics. USBM personnel designed a monitoring network, supervised installation of sampling wells, and collected and analyzed water samples. This Report of Investigations describes interpretation of data collected between December 1989 and April 1992. The computer program WATEQ4F was used to identify aqueous species distribution and to calculate potential solid phase controls of solubility. To assist in interpretation of changes in water quality between sampling locations and to develop models describing proposed flow paths, the computer program BALANCE was used. Using output from these programs and field observations, a description of the chemistry along proposed ground water flow paths at the mine is presented.

Jan 1, 2010

By Karl J. C. Harries

"12.1. NO DEPRECIATION/GAAPAll calculations and computations relating to the Royalty shall be carried out in accordance with generally accepted accounting principles consistently applied to the extent that such principles are not inconsistent with the provisions of this Schedule and the agreement attached hereto, it being specifically agreed that nothing herein contained shall permit, or be construed to permit, the Operator to deduct any amount for depletion, depreciation, amortization or any deduction that represents a non-cash outlay.Comment: In cases like net profit royalties where recoupment of prior expenditures is permitted, care should be taken to avoid any implication that depreciation may also be taken. It is only logical and equitable that Property Owners should not be permitted an apparent ability to “double dip” with respect to deductions. A provision like this example should accomplish the task. It will be noted that the example specifically contemplates that the negotiated arrangements will prevail over any requirements of GAAP. Accordingly, if the parties agree to an unusual formula for recoupment, it will not be set aside to accommodate GAAP requirements. Under GAAP, revenues and expenditures are accounted for on an accrual basis. In addition, it specifically prohibits the taking of non-cash deductions, which is in keeping with the concept of recoupment.Although in some ways the example states the obvious and could be considered redundant, its presence, especially in provisions contemplating recoupment, makes it clear to the financial people that there may well be some variations from normal practices dictated by GAAP, while at the same time confirming the availability of GAAP to fill any voids.The accounting profession often makes the caveat that application of GAAP is an “art”, not a “science”. GAAP do not provide a cure-all and can create problems that will have to be addressed. For example, GAAP contemplate that asset costs are to be reduced by investment tax credits, which can cause a problem for a payor with more than one mine."

Jan 1, 2003

By Jr. Frank Parrish

This report describes the performance of 17 selected water-injection projects producing from Pennsylvanian-and Permian-age reservoirs. Illustrations depict reservoir structure and thickness, and production and injection history. A selected bibliography of publications pertaining to area oil recovery and geology is included. Tabulations of field and reservoir data reveal marked differences in the projects. Increased oil recovery resulted from injecting water in most cases; however, seven projects recovered less oil than the operators anticipated. Oil recovery by water injection ranged from 0.2 to 262 bbl per acre ft, or 0.1 to 22.5 pct of the initial stock-tank oil in place. Major reasons suggested for poor performance include: (1) Adverse directional horizontal permeability, (2) channeling of injected water through fractures or zones of high permeability, and (3) lack of containment of injected water. One 330-foot-deep project is among the first successful shallow water-floods in north Texas. Another project is the first successful Canyon sand-stone waterflood reported in the area. Previous gas injection in two Cisco sandstone projects did not prevent the reservoirs from responding favorably to waterflooding.

Jan 1, 1965