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By C. A. Rawlins, P. Rostami

"Ventilation systems are not only an integral part of any underground mine design but are a significant contributor to the mine’s capital and operating costs. The ventilation and cooling design systems presented in this paper were part of the prefeasibility evaluation of an underground platinum mine in South Africa. The mine would ultimately operate at the depth of 1,200 m below surface with a proposed 4 Mtpa production rate. The proposed mining operation is a highly mechanized operation using diesel equipment. Significant daily production rate, large amount of equipment and expansive nature of the operation, contributed to a challenging while flexible ventilation design requirements. This paper presents how to safely and efficiently optimize capital expenditure and operating costs associated with the mine air cooling and refrigeration system through practical ventilation design practices. Successful capital and operational savings by modulating installation and commissioning of refrigeration facilities can influence the economic realization of such systems. The adapted planning and design approach provided a cost-effective advantage while complying with design safety and regulations. INTRODUCTION This paper outlines a prefeasibility evaluation of the heat loads and related cooling system to be employed at the proposed platinum mine. The paper also provides appropriate details for a comprehensive understanding of the applied methodology. The proposed mine will be a trackless underground operation using a combination of mining methods. Initially, ore zones with vertical thicknesses greater than or equal to 18 m will be mined using the long-hole stoping (LHS) method, while thinner ore zones will be mined using mechanized drift-and-fill or drift-and-bench methods; hence, a highly mechanized operation with LHDs, trucks, drill rigs, personnel carriers, etc. is envisioned. Broken rock (ore and waste) will be transported by the means of trucks to the main passes (ore and waste) and collection points. Mining zones identified in the project occur at depths ranging between approximately 700 m to 1,600 m below surface. Primary access to the mine will be via a 1,100 m deep, 10 m diameter production shaft (named Shaft No. 2), three additional shafts will be sunk to provide future ventilation and production support. Three main access levels are established as primary haulage levels and include a series of interconnecting ramps. Additional mining sublevels will be developed as necessary. Figure 1 shows the proposed shaft locations and main access levels in a 3-D elevated view. Mining is performed using highly productive mechanized methods. For this reason, an annual ventilation estimate is based on requirements for mobile equipment (i.e., 0.06 m3/s/kW). The air requirements imposed on the underground operation is further influenced by equipment heat loads, auto compression, and virgin rock temperature, as the main sources of in-mine heat."

Jan 1, 2015

By S. Tafazoli, D. Cooper, I. Bell, S. Nouranian, B. Sameti, M. Ramezani

"Image-based rock fragmentation sensing in mines and quarries includes an important rock boundary delineation step, commonly referred to as rock segmentation. This paper presents an artificial intelligence-based solution to this challenge. The proposed technique encodes prior knowledge of previously analyzed images into mathematical/statistical models. Human-labeled images are used as inputs to train neural networks through an optimization process. The networks can then be used in real time for rock delineation. To build the models, special deep artificial neural networks are used as a pixel classifier. The proposed classifier labels each pixel (edge, rock or fine) by analyzing a plurality of pixels within the image. Advances in machine learning allow the network to contain many parameters. The increased number of parameters is a strong factor in the classifier’s ability to correctly classify each pixel. Deep learning-based segmentation, combined with 3D imaging followed by post processing, provides a unified fragmentation sensing solution. Results from automatic segmentation are compared to human labeled segmentation using the percentage passing curves for 64 rock images. INTRODUCTION Mines and quarries can see significant productivity and performance benefits by controlling material sizes (McKee, Chitmobo, & Morrell, 1995; Sellers & Gumede, 2012). During the past decade, image-based fragmentation analysis has been applied to estimate rock size distributions in order to optimize procedures in mines and quarries. Using a roving camera and operator assisted analysis Maerz, Franklin, and Coursen (1987) measured the size distribution of the blasted rock and eliminated the need for manual sieve analysis. Since then, many others have introduced automated and manual methods for fragmentation analysis and improved upon existing approaches (Girdner, Kemeny, Srikant, & McGill, 1996; Smith & Kemeny, 1993; Palangio, Palangio, & Maerz, 2005; Tafazoli & Ziraknejad, 2009; Raina, 2013). In image-based fragmentation, rock boundaries are identified in the image, and an image scaling is applied to transform rock pixel sizes into real world dimensions. Usually geometric references, such as regularly shaped objects (discs and basketballs) (Siddigui, Ali Shah, & Behan, 2009), or the known size of an excavator bucket (Zeng, Chow, Baumann, & Tafazoli, 2012), are used to determine the proper scaling factor. In recent years, 3D imaging and sensing have also been incorporated to improve rock delineation. Specific methods include using camera-laser combinations and stereo imaging to measure rock fragmentation on conveyor belts (Noy, 2013; Thurley, 2013; Dislaire, Illing, Laurent, & Pirard, 2013) as well as portable fragmentation analysis devices with 3D imaging sensors (Sameti, et al., 2014)."

Jan 1, 2018

By J. V. Thompson

The Powderhorn complex as a source of perovskite (calcium titanate) containing about 1.5% rare earths has been examined in several recent feasibility studies. Much promising exploration and process research has been done in recent years. This paper is presented with cautious optimism and with the acknowledgment that there may be some technical and economic areas yet to be explored. The Powderhorn carbonatite and alkalic stock in Gunnison County, Colorado, lies about 203 airlines km southwest of Denver at an elevation of 2450 to 2750 m (see Figures land 2). All of the mineable ore bodies are owned by Buttes Resources Company of Houston, Texas.

Jan 1, 1990

By Y. C. Guan

The cementation of gold on to copper and zinc in ammoniacal solutions has been studied using rotating disc electrodes. The cathodic reduction of aurous ammine was studied on a gold rotating disc electrode and the anodic dissolution of copper and zinc was studied in the absence of aurous ammine. The cementation rate was found to be a first order with respect to the concentration of aurous ammine and to be proportional to the square root of the disc rotating speed. Based on the results obtained, it was concluded that the cementation reaction was controlled by mass transfer of aurous ammine to the reaction surface under the experimental conditions.

Jan 1, 1995

By Sam H. Patterson

Fuller's earth and bentonite are two clay commodities that are interrelated either by mineral composition or use. Because of this interrelation and the sale of both for many different uses, some ambiguity in their classification has resulted. The term "fuller's earth" has no compositional or mineralogical meaning, and it is used more or less as a catchall for any clay or earthy material suitable for certain uses. Most, but not all, of these uses require absorbent properties. Bentonite by geologic definition must have formed from volcanic ash or tuff or the glassy material in volcanic rock; most bentonites consist chiefly of montmorillonite but other clay minerals may be present. In industrial usage the term "bentonite" is applied to any clay consisting chiefly of montmorillonite, irrespective of origin. Georgia and Florida have historically been the leading States in the production of fuller's earth; bentonite has been produced in Alabama on a small scale. The first major use of fuller's earth was in refining of oils. Other materials have replaced fuller's earth for this purpose to a major extent, but many new uses for fuller's earth have been found, and production has increased in recent years. The new uses include absorbent products, insecticide and pesticide carriers, drilling mud, and many others. The bentonite now produced in Alabama is of the "southern," "low selling," or "calcium" type and is used mainly as foundry-sand bond. Most of the fuller's earth mined now is in the Hawthorn Formation of Miocene age; a lesser amount is produced from the Twiggs Clay Member and other beds in the Barnwell Formation of Eocene age. Inactive pits from which fuller's-earth was produced from other formations occur at several localities. The bentonite now mined in Alabama is in beds of Cretaceous age; several years ago bentonite was produced from Eocene beds in this State.

Jan 1, 1972

By C. J. Konya, A. Konya

"Presplitting is a form of blasting that when executed properly will create a smooth wall that will minimize secondary conditioning. In recent years, presplitting has become a popular technique to be used in both the mining and construction industry, however, presplitting fails on many occasions because of ‘geologic conditions’. This is typically because of improper explosive loads consisting of overloading and underloading blastholes. In this paper the authors introduce new factors such as a presplit factor which varies for different rock types, selection criteria for the spacing of presplits, the optimization of explosive load, as well as prediction methods for the environmental affects for the technique of Precision Presplitting. BACKGROUND Methods of controlled blasting in which a smooth, stable wall could be blasted have been an important consideration since blasting in mining and construction has begun. How can one use an explosive, with its massive energy and power, to break a non-homogenous rock without causing backbreak, poor walls, or deviations in the wall over large distances? The blasting industry has known for a long time that blasting ‘high benches’ would result in better walls and less backbreak. However, this was not a sufficiently controlled technique for critical projects, such as the Niagara Power Plant. This was one of the main challenges Hercules Powder faced when they began the project. In order to achieve this, they used a new tool in the explosive engineer’s toolkit, presplitting. The presplitting done on the Niagara Power Project utilized 1 ½” x 8” (38mm x 203mm) 40% gelatin dynamite in 2 ½” (63.5) diameter boreholes. This was done on multiple levels with benches between 12 feet to 52 feet (3.6m to 15.8m) with a total powder factor of 0.75 pounds/cubic yard (0.45 kg/m3). The spacing on these holes ranged between 18 inches to 24 inches (0.46m to 0.61m), center to center (Langfors & Kihlstrom, 1973). The strange aspect of this project was that this “lightly loaded” closely spaced row was fired before the production blast, yet this project produced some of the best walls seen at that time directly from blasting. In today’s blasting industry, presplitting is a more common way to produce smooth, stable high-walls for both the construction and the mining industry. Today, explosive loads for traditional presplitting is generally measured in pounds per foot (kilograms per meter) and typically ranges from 0.30 lb. /ft. to 0.5 lb. /ft. (0.45 kg/m to 0.75 kg/m). MECHANICS OF PRESPLITTING When analyzing a blasting process like the Niagara Project, many wonder how did that work when normally confining a charge would cause cratering and increased backbreak. Since then, presplitting mechanics have been studied extensively. It has been shown in many models that presplitting is not achieve through the collision of shockwave, but by gas pressure in the boreholes. In addition to models and finite element simulations, this has been proven full scale using Pyrodex, a propellant, to create a presplit plane with no shock wave present (Konya, Dean Barrett, & Smith Jr, Presplitting Granite Using Pyrodex, A Propellant, 1986)."

Jan 1, 2017

By G. Hoffmeyer, I. Ream

"Several copper projects exclusively utilizing in-situ recovery methods are currently under development in Arizona. Favorable conditions for In-Situ Copper Recovery (ISCR) include a saturated orebody, fracture hosted mineralization, hydraulic conductivity sufficient to effectively inject and recover solutions using wells, and a relatively flat background hydraulic gradient. Safe operation of an ISCR project requires that the operator have the ability to induce and maintain localized hydraulic gradients, thereby controlling the movement of injected and recovered solutions. Benefits of ISCR include reduced initial capital, and a greatly reduced environmental footprint. THE ISCR METHOD EXPLAINED The method chosen to extract a mineral from a deposit is driven by characteristics such as its size, grade and depth of burial. Large lower grade deposits that require significant excavation to access using surface methods are potential candidates for in-situ recovery. ISCR may also be ideal for smaller deposits due to the lower initial capital. However, regardless of the size of the deposit, certain hydrogeologic conditions must be present for ISCR to be successful. In-situ recovery methods do not require excavations of rock from the surface or underground, resulting in a dramatic reduction in surface disturbance when compared to conventional mining. With the ISCR method, what is visible above ground is the processing plant, well heads, piping, process solution impoundments and evaporation ponds. There are no waste rock piles, tailings impoundments, leach pads, or impacts associated with blasting and hauling. Other benefits include reduced initial capital, reduced dust and noise, and lower water use. Early testing of the in-situ copper recovery method by Occidental on the Van Dyke deposit east of Phoenix and by Kennecott at Safford Arizona in the 1970s produced encouraging results, but the permitting regime for a large-scale operation was not yet in place. Additional testing and commercial application of in-situ copper recovery techniques have expanded since the 1980s, most commonly in conjunction with open pit or underground mining operations. For example, several operations in Arizona (San Manuel, Miami East and Tohono) have used in-situ techniques to extract additional copper following conventional mining from parts of the deposits adjacent to open pits or underground workings. Where the rock has been broken up by conventional methods, the method is called “in-place” leaching. The US government has also been involved in assessing in-situ techniques. For example, joint research was conducted by the US Bureau of Mines and industry on the Santa Cruz deposit in Arizona; and both federal and state agencies have been involved to establish the comprehensive permitting regime that exists today. Currently there are several projects in Arizona being evaluated as stand-alone ISCR operations."

Jan 1, 2016

By E. C. Skinner

As the program says -we'll he talking about the expectations of the Management of an Industrial Mineral enterprise relative to the activities of geologists engaged in that enterprise. Industrial Minerals is such a large industry both in tons produced and in value of product -and of such diversity and complexity of participating enterprises, minerals and products that I doubt if anyone person can speak for the entire industry as to the expectations of management with respect to the geologist. I'm sure there are major differences in emphasis between segments of management as to the relative importance of the different aspects of the geologists' role in the scheme of things. However, we will try to generalize concerning what we consider to be important factors and to be more specific perhaps of some of the factors with which we have had direct assessable experience.

Jan 1, 1972

By Julian W. Feiss

Before undertaking to present to you a current analysis of copper, I would like to preface my remarks with a few observations that in themselves have a bearing upon commodity reviews in general. Having sat through a large number of such reviews since first joining the A. I. M. E. nearly forty years ago, I have no illusions about the hazards of the undertaking. If a speaker presents a statistical summary of commodity economics for the last year, most of his audience, having already read at least four commodity summaries on the identical subject, either get up and walk out or fall asleep. Should the latter happen, and were the listener to tumble from his chair and break his neck, obviously the speaker is liable. The subject matter seldom lends itself to histrionics on the part of the speaker so dangers of heart attack in the audience are not too great. Therefore the speaker, in order to retain listener interest, resorts to prophecy. Such venture was undertaken long ago by weather soothsayers, the "harouspex" of Ancient Rome, who generally cut up a sacrificial sheep and after staring at the entrails made their predictions which I understand had a batting average somewhat better than those undertaken on Wall Street based upon Dow Jones averages. Not being a licensed harouspex I cannot undertake predictions. I shall, however, fall back upon the experts.

Jan 1, 1965

By V. de Macedo Torres

There are technical and commercial limitations on using high fluorine copper concentrates in industrial copper smelters. The presence of more than 1000 ppm of fluorine in copper concentrates affects the sulfuric acid units generally integrated to copper smelters, and penalties are normally applied to high fluorine concentrate prices. Several process alternatives to this issue were studied at CVRD Technology Center (SUTEC): modifications on conventional sulfuric acid plants to use high fluorine concentrates, removal of fluorine containing minerals in flotation using depressants, selective leaching of fluorine minerals and sulfuric leach of copper concentrates. Finally, a hydrometallurgical process of removing fluorine was developed by SUTEC.

Jan 1, 1997

By Angus Maxwell, Jacob Grasmick

As the tunneling industry continues to adopt Tunnel 4.0, digital twins of the tunnel construction site are becoming standard requirements for tunneling projects. However, the benefits of these remain unproven to many practitioners. The paper discusses the various implementations of digitalization and describes efforts to combine all data types to analyze the relationships between influences, predictions and performance in a single digital platform. This includes data pertaining to investigations, design, construction, monitoring and post-construction asset performance and management. Based on 16 years of global tunneling projects the paper aims to quantify the tangible and intangible benefits of such systems. Using a number of real examples, the paper describes where opportunities were taken and where they went unrealized. Challenges and considerations for both procuring and developing these digital twins are also discussed.

Jun 13, 2021

By James R. Garvey

The impact of conversion on the coal industry can be summarized very briefly: We are going to have to mine an awful lot of coal. Fortunately, the United States has the coal reserves available, and given the right conditions, we can mine it. The coal reserves of the United States are enormous. If we consider them on the basis of proved reserves, using the standards of the petroleum industry--that is, resources mapped and explored and recoverable with present techniques at close to present costs--and compare that with the reserves of other fuels, coal constitutes 88 per cent of the proved recoverable energy resources of the nation. That includes oil, natural gas, oil shale and uranium, so long as the uranium is used in burner reactors. If we consider resources on the basis of "ultimate recoverable" reserves, that is, those resources which can be extracted with improved technology and at somewhat higher costs--and if we include those resources of all fuels not yet found but believed to be waiting discovery--coal still accounts for 74 per cent of the national total. We have built a hydrocarbon economy in which about 76 per cent of our total energy needs are supplied by petroleum and natural gas, and about 20 per cent by coal. Domestic resources of oil and gas are running dangerously low and, assuming a continued hydrocarbon economy, the 20 per cent supplied by coal may increase dramatically. We already import nearly a quarter of the petroleum we consume, and the chief source of additional imports seems to lie in the politically unstable Middle East. Natural gas is in even shorter supply, and the problems of importing it seem at least as difficult as those of oil. The fact is, the United States is already relying to an increasing extent on foreign fuel sources. There is an obvious national risk in making an important part of energy supply hostage to foreign governments of uncertain tenure and friendliness. There is also an economic risk--one of the chief reasons for last year's economic freeze was to try to correct the deficit in our balance of payments; it is obvious

Jan 1, 1972

By Daniel E. Collins

Massive banded Fe-Zn-Cu-Pb sulfide deposits in the Bagdad are associated with metamorphosed eugeosynclinal mafic volcanic and intrusives rocks Precambrian age. The geologic environment is very similar to that of the Jerome-Prescott area which lies 70 km. east of Bagdad. Mining of massive sulfides deposits began in 1917 on the Copper King mine in spite of its early discovery and the discovery of the Old Dick mine in 1882. The first shipments of zinc ore from the Copper King were hand sorted and averaged 46.89% Zn, 5.7 oz. Ag, 3.58% Pb and 1.68% Cu. Oxidized copper was first produced from the Old Dick mine in 1943~ In all, five deposits of massive sulfide ores have been mined in the Bagdad for a total production of nearly 2 million tons with an average grade of 12.0% Zn and 3.6% Cu. The largest deposit, the Bruce mine is currently closed because reduced metal prices and has produced a total of 823,000 tons of Zn-Cu ore to date. Mining of massive sulfide ore in the Bagdad area is presently idle. However, the potential for locating yet undiscovered ore bodies is good. Exploration for new ore bodies is difficult at best due to the complex geologic history of the area, the small size of individual ore bodies and lack of understanding as to the formation of massive sulfide deposits. The purpose of this investigation was to obtain a better understanding of the host rock formations through detailed geologic mapping, petrography and chemical analysis.

Jan 1, 1977

By S. Upadhyay, A. M. Afrapoli

"Fluctuation in market price of mineral products has enforced mining companies to cut down their operating costs. One useful way of reducing operating costs in mining operations is to make optimal operational decisions, incorporating efficient mining fleet management systems (FMS). Over the last 50 years, several types of FMS have been developed and introduced in the mining systems around the world. However, there are two major shortcomings in existing systems. Firstly, none of the existing systems consider effects of the short-term plan on dynamic truck assignment. Secondly, most of the existing FMSs make decisions in a way that optimize a specific objective while ignoring others. Herein, we propose a multi stage and multi objective FMS that deals with aforementioned shortcomings of the currently available systems. The developed FMS, in its upper stage, links semi-dynamic operational decision making process to the short-term production plan by simultaneously assigning shovels to mining faces and allocating trucks to the shovels by implementing its first multi objective decision making model. Then in its second stage, in a real time dynamic decision making process, it assigns trucks to shovels and corresponding destinations by optimizing its second multi objective decision making model. The developed fleet management system has been verified using an Iron ore case study and the results are presented in this paper. INTRODUCTION Open pit mining method is the most common method to mine mineral from the earth. Based on Wetherelt and van der Wielen (2011) there exist 2500 open pit metal mines that are categorized as industrial scale mines. Over all of those, the amount of material handled using truck and shovel material handling system is more than the amount handled by all other systems together (Humphrey & Wagner, 2011).It has been proven by several studies that more than 50 percent of operating cost in a truck and shovel based open pit mining operation is accounted for material handling (Moradi Afrapoli & Askari-Nasab, 2017, Alarie & Gamache, 2002, Ahangaran et al., 2012). Thus, introducing even 1 to 2 percent cut in its material handling cost saves huge amount of money for the stakeholders. Over the last 50 years, two major areas have been identified to cut this cost. On one hand mining industries have been implementing equipment with higher production capacities, and on the other hand, researchers have been developing operations research techniques to make dynamic decisions as close to optimal as possible to deduct operational costs in truck and shovel based mining operations."

Jan 1, 2018

By Bruce Congleton

One year ago this month, we in Central Florida witnessed the beginning of a most exciting and glamorous attraction. After three years of construction and anticipation, Walt Disney World opened its gates near Orlando and during its first year of operation received a flood of over 10 million visitors---half of all who came to Florida last year! The side effects of this newest addition to Florida have been phenomenal. Traffic on heavy days has been backed up for 30 miles from the amusement park along a major interstate highway. Hotels and motels have been jammed packed for months, and reservations are still difficult to make. Gasoline stations, restaurants and souvenir shops are doing a booming business. Everywhere you look as you ride the highways of Central Florida you see the signs of growth. New hotels spring up almost overnight. Golf courses galore. New housing projects and apartments sprawl where orange groves used to be. New roads criss-cross areas which were once deserted. There seems to be no end to the steady influx of tourists and new residents to the Sunshine State. And it's mainly because that we are the Sunshine State that they come. Air and water pollution is and has been at a minimum in Florida. Pollution and emissions are fighting words among some groups dedicated to preserving the bountiful environment we share in Florida. Little wonder then that some of these people display concern when they learn that just 50 miles from the entrance to the Magic Kingdom of Disney, phosphate draglines strip away thousands of acres of land each year to extract one of our nation's most precious

Jan 1, 1972

By Lawson. Heather

"The purpose of this study is to explore how the geochemical and petrographic components of coal may impact its physical properties, as well as how these components correlate with a history of reportable dynamic failure in coal mines. Dynamic failure events, also termed bumps, bounces, or bursts, are the explosive failures of rock in a mining environment. These events occur suddenly and often with no warning, resulting in worker injury up to and including fatality in greater than 60% of MSHA reportable cases. A database of variables was compiled using publicly available datasets, which included compositional geographic, strength, and Hardgrove Grindability Index (HGI) data (ACARP, 1998). Results indicate that bumping coals are less mature, lower in carbon, higher in oxygen, softer, and less well cleated than coals that do not bump. High liptinite content was found to correlate with higher average UCS values. However, no clear, direct correlation between UCS and dynamic failure status was observed. The findings of this study establish that differences exist between coals that have experienced reportable dynamic failure accidents versus those that have not. These differences are inherent to the coal itself, independent of mining-induced risk factors. Results further illuminate how compositional attributes of coal influence physical properties and begin to clarify potential links between geochemistry and dynamic failure status. Only through the better understanding of risk can more effective mitigating strategies be enacted.INTRODUCTIONDynamic failure events, also termed bumps, bounces, or bursts, are the sudden failures of rock in a mining or quarrying environment. Failure occurs when the rock’s critical bearing capacity has been exceeded and the rock fails energetically through the outward expulsion of rubblized material (Peng, 2008). These events occur suddenly and often with no warning, resulting in worker injury up to and including fatality in greater than 60% of reported cases through the Mine Safety and Health Administration (MSHA). Much research has been devoted to the prevention of these events. The effects of overburden depth and stiffness, mine design, mining practices, and in situ stresses are well documented (Agapito and Goodrich, 2000; Brauner, 1994; Campoli and Kertis, 1987; Holland and Thomas, 1954; Iannacchione and Zelanko, 1995; Lawson et al., 2016b; Mark, 2016; Newman, 2002; Peng, 2008; Whyatt, 2008). Despite these significant advancements in coal mine ground control, however, events continue to occur. Proactive risk mitigation remains an important research area. This is particularly true in underground coal settings, where the rockmass is layered, lithologically diverse, and does not exhibit consistent material properties across deposits.Many conditions have been associated with the occurrence of dynamic failure phenomena, including:"

Jan 1, 2019

By Mark Alan Marlkos

Blebs of solid bitumen from the Magmont West orebody of the Viburnum Trend were examined and analyzed in an attempt to relate hydrocarbon distribution and origin to ore genesis. The bitumen was calculated to be approximately 48 to 63 percent aliphatic and is considered to be a polymerized normal crude oil. Polymerization, which was probably caused by water-washing, hardened the bleb surfaces and appears to have "frozen" the blebs during primary migration from local source beds. Comparison of the bitumen to kerogen in local shaly partings strongly Indicates that the oil was derived locally. The polymerized oil blebs are considered to have been derived from a type II (marine) kerogen. Textural analyses indicate that oil migration occurred after lead-zinc mineralization and at temperatures that exceed normal ancient or present geothermal gradients. The following sequence of events is postulated for the Magmont West orebody: 1 Generation of hydrogen sulfide during diagenesis of a normal organic-rich carbonate sequence. 2 Introduction of pulses of hot, metal-rich fluids that resulted in: a Lead-zinc mineralization by the following reaction: Me++ + H2S ? MeS + 2H+ b Solution of carbonates by excess acid produced during the above reaction. c Brecciation of host rock in some cases. 3 Passages of the pulse resulted in: a Carbonate buffering of fluid system to more alkaline conditions. b Precipitation of dolomite c Slight temperature drop. 4 Eventually the high temperatures Introduced by heated brine caused oil generation and initiated primary migration. 5 Water-washing and mild biodegradation altered the hydrocarbon blebs to their present composition.

Jan 1, 2013

By R. W. Lake

The decision to develop an ore body can lead to multi-million dollar profits, or equally substantial losses. Accordingly, the effort required to adapt a valuation model to the specific proposal at hand, or even the development of a new model from basic principles, is clearly warranted. In the formulation of a model of this nature, one is faced with some major questions. For example, with the long term obligations that it implies, on what basis should a decision to initiate mining operations be made? Furthermore, how can the vagaries of inflation and the uncertainties that shroud the future be accommodated? Beyond the general principles by which mineral deposits are evaluated, specific cost behaviour is a function of the geology of the deposit, and of the mine design. Moreover, mine design, during the life of the mine, must be a continuing process somewhat akin to dynamic programming. An initial, apparently optimal, design is selected and mining commences. With production, a continual process of information updating leads to revisions. Thus if the maximum value is to be obtained, the mine design must be adjusted to conform to the changed conditions.

Jan 1, 1977

By R. Chandramohan, Landon Jackson, C. Meinke

Understanding constraints within the raw battery material supply chain is essential for making informed decisions that will ensure the battery industry’s future success. The primary limiting factor for long-term mass production of batteries is mineral extraction constraints. These constraints are highlighted in a first fill analysis which showed significant risks if lithium-ion batteries are used to fully support vehicle electrification and intermittent energy storage. Nickel, lithium, cobalt and graphite reserves risk 100 percent depletion with significant consumption of known resources. Furthermore, more than 700 new critical mineral mines will need to be developed to meet the required production rates for decarbonization by 2050. Demand for critical minerals will outpace mine development timelines even as improvements are made to battery energy density and compositions. Governments and the private sector need to align themselves on decarbonization goals to establish cooperative agreements on the critical mineral supply chain by reducing the barriers to entry and increasing exploration efforts. Additional measures must also be taken to reduce the demand for critical minerals. Policy such as incentivizing public transportation and biking infrastructure can be exploited to drastically reduce the mineral demand placed on the mining industry.

Feb 1, 2025

By Gerry Norton

The purpose of this paper is to make the most complete assessment of coal cleaning methods, both process and equipment related to modern-day production and environmental requirements. In order to achieve this primary objective, a number of interdependent aspects of coal cleaning technology require evaluation and analysis. 1.0 CLASSIFICATION OF SEPARATION PROCESSES Processes and cleaning equipment can be categorized according to the important parameters of 1) mechanics of separation, 2) size range application, 3) range or variance in accuracy of separation related to 2) above, and 4) feed-size ratio affecting 3) above.

Jan 1, 1977