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By John B. Gustavson

Gold was first discovered in Alabama in 1830. Before a decade had passed more than 20,000 people were employed in the various gold districts scattered across east-central Alabama. By 1849 most of the presently defined gold districts were known with such towns as Arbacoochee, Chulafinnee, Goldville, Pinetucky, and Idaho being the principal mining camps. The California gold rush of 1849 signaled the end of intensive prospecting in the Alabama Piedmont for the precious metal. Reactivation of many of the old gold districts has been attempted several times since 1849. Significant activity and development took place between 1874 and 1880, 1888 and 1916, and 1929 and 1936. Locally, some of the development met with moderate succes. The last productive gold mine in Alabama ceased production in 1935. The sharp increase in gold prices since 1973 has caused renewed interest in the potential values of gold of the Alabama gold districts. Most of the gold workings have been abandoned for nearly 75 years and are for the most part inaccessible for convential property evaluation. The early gold miners and prospectors in Alabama were more intent upon finding and mining the valuable metal than in recording their activities for future generations. No matter how interesting or historically significant these records might have been the miners kept no records and left behind them few maps as clues to their activities. Inasmuch as most of the old gold districts have been extensively mined and prospected during the past 150 years, there is very little chance of finding large deposits through conventional outcrop prospecting methods. Similarly, the present geologic knowledge of the various districts is insufficient to launch successful exploration programs looking for large blind lode deposits in new locations within the general gold bearing region.

Jan 1, 1975

By John Dean

"Pumping backfilling medium used to fill in holes and caverns in mines is challenging. The often viscous, high solids materials are extremely abrasive and can destroy pumping systems in a matter of days. While a number of options are available, using a progressing cavity pump can often be the best solution. High pressure and capacity capabilities, coupled with low wear rates, ensures reliable cost effective operation.Thickened slurry backfilling for underground/excavation mining applicationsVoids and caverns develop as a result of mining operations penetrating deep into the earth seeking natural resources. After extracting all the ore from a mine, operators need to fill in these voids to preserve the integrity of the mine structure. They do this by pumping in a backfill medium. Each mine uses a different mix of components for backfilling, depending upon the mine’s specific structural requirements and environmental concerns, particularly water requirements. Most backfill mixes contain cement, or another cement-like substance, that acts as a binder to hold the backfill medium together. This is combined with tailings (unused rocks and waste from processing and/or extraction), and may also include chemicals or other binders to increase the material’s strength.Backfill pumping challengesPumping the backfilling medium can be a significant undertaking. This process involves transporting very viscous and high solid materials; the mix may contain 60-80 percent solids. These backfill slurries are extremely abrasive and the viscous material can wreak havoc with pumping systems. The material’s paste-like consistency presents problems for standard centrifugal pumps often used in other mining applications.Added complexity is posed when trying to achieve the required pressure, which depends upon how far away the material has to be pumped. It is not difficult to meet the pressure requirements if mixing the backfill material close to the area to be filled. However, pumping from extreme distances can be problematic — a great deal of pressure is required to transport the material from the mixing area to a distant backfilling site. Ideally, operators should be as close as possible to where they are filling, so they can use a smaller pump with lower power requirements."

Dec 1, 2018

By M. Adnan Goksel

A blast furnace test of approximately 5,000 tons of PelleTech Corporation (PTC) cold bond pellets was successfully run at Kaiser Steel Corporation (Kaiser) Steel Manufacturing Division at Fontana, California. The pellets were produced from mill scale, BOF dust and blast furnace flue dust. A 15 day base period, during which time the metallic burden was 2/3 heat indurated pellets and 1/3 sinter, preceeded the test. During the test period the metallic bur- den was 10% cold bond pellets, 56.7% heat indurated pellets and 33.3% sinter. A 15 day post test base period followed during which the PTC pellets were replaced by conventional pellets. The pellets were produced in the 3.C Semi-works Facility located on Kaiser property. The facility incorporates the Michigan Technological University Hydro-Thermal Agglomerating Process.

Jan 1, 1979

By John R. Bogert

The title of this session is "Wall Street Looks at the Mining Industry," and I am going to attempt to answer the question: Shouldn't Mining Stocks Sell at Higher Price Levels? Or, What Does Wall Street See When Looking at the Mining Industry? Well, it sees a capital intensive business, a technical industry, and a growing industry becoming more vertically integrated. But, at the same time, Wall Street sees a cyclical industry, a fragmented industry of erratic earnings, spotty public relations, a feast-or-famine business where the public usually does not differentiate between coal mining or metal mining, and does not appreciate either the risks or the rewards. As a result, mining stocks generally sell at relatively low price learnings ratios in comparison to other industrial groups. This PIE ratio, the current market price of the capital stock divided by annual earnings per share, is probably the most popular index of a stock's value. The average of the price/ earnings ratios of the 30 stocks comprising the Dow Jones Industrial Average is over 14. This diverse group of stocks is widely regarded as being a cross-section and representative of the industrial companies listed on the New York Stock Exchange. However, in comparison to 14, Asarco and Kennecott shares are currently available for about 8 times annual earnings. Even discounting earnings from South America, the stock of these two companies sells at only 10 times earnings. Of course, Peruvian politics is currently preventing Cerro shares from selling above 6 times earnings, and Chilean politics keeps Anaconda shares at a PIE multiple of 7. However, even in better times, these companies rarely sell above 10 times earnings. American Metal Climax and Newmont sell at only 11 times earnings as does Phelps Dodge and St. Joseph Lead. Few mining companies then have what can be considered a high PIE ratio-a figure higher than

Jan 1, 1970

By M. A. Ouederni, G. C. Chorosz, E. P. Déliac

This paper deals with the heat flow problems in deep workings (depth greater than 1000 m in France). The approach benefitted from experience gathered in France and South Africa. Deep mines are located in the East of France (coal in Lorraine and potash in Alsace), where the geothermal gradient can reach 4 'C per 100 m (Virgin Rock Temperatures, VRT, around 50 'C). This paper is concerned with the following topics: method of studying the heat flow problem on a mine-wide basis, specific models for heat and moisture pick-up, interfacing of heat and ventilation calculations and a case history in the Lorraine collieries. The heat flow problem on a mine-wide basis is studied in a fashion similar to ventilation networks. Each branch is considered as a "black box" where the air picks up heat and moisture (or is cooled, in the case of an air-cooler). Each box is therefore modeled as a heat transfer unit, hence the calculation of outlet temperatures (wet- and dry-bulb) from the intake ones. The whole network can thus be computed as a sequence of boxes from the air intakes towards the outlets. The second section reviews a number of models used for the assessment of heat and moisture pick-up in the "boxes", with emphasis on stopes and development ends, which are particular to the mining method in use. Two types of stopes are considered: longwall (horizontal and inclined) and cut-and-fill (subvertical). Mechanized rock breaking and blasting can be accounted for. A particular attention is given to development ends, especially complex from the heat flow point of view (rock characteristics, wetness factors, etc.) and usually quite hot. These workings, which are critical in order to secure new production areas, are studied on an average basis as well as in extreme conditions. The calculation takes into account the history of rock temperatures. The interaction between ventilation and thermodynamic calculations is still under development. The idea consists of coupling ventilation calculations with the "box" models: the first step determines the direction of air flow, hence the sequence of the boxes; thereafter the calculations yield the effect of temperature and presssures on air flows. The final section reports on the validation of the whole approach against field data. It concerns several heat flow surveys aimed at checking the models for shafts, stopes and development ends. The accuracy of the method is found very satisfactory.

Jan 1, 1987

By Carla L. Zenti

In recent years, considerable advances have taken place worldwide in the design and construction of first tunnel linings. With these advances, there is a tendency to move away from traditional support that includes heavy open profiles of rolled steel arches, to a lighter solution with the use of an optimized tubular steel cross section rib, and shotcrete reinforced with steel mesh and/or steel fibers, providing a continuous support (Lunardi, 1982). The development of tubular ribs has provided greater design options, increasing flexibility to engineers and contractors while providing a efficient and cost effective construction method. In this article, the authors describe numerical and experimental investigation on this problem, suggesting as a new first lining steel arch design approach by using tubular ribs cross section as new technical solution for first lining underground support.

Jan 1, 2012

By Stanley W. Ivosevic

The South-Central area of the Osa Peninsula, Puntarenas Province, on the Pacific coast of southern Costa Rica, may have produced on the order of 30,000 kg (100,000 troy oz) of gold since prehistoric times. The Peninsula lies along an 800- to 900-km-long belt of late Mesozoic eugeosynclinal rock deposition, hydrothermal activity, and deformation (Campanian). The oldest rocks exposed in the area are basalt and tuffaceous mudstone of the Late Jurassic or Cretaceous Nicoya ophiolite complex. The Nicoya Complex is overlain by weakly lithified Pleistocene Older Sediments, predominantly conglomeratic sandstone and derived from erosion of the Nicoya Complex. Erosion reduced the Complex to a surface of high relief, so that the detrital source was in the area originally; the source retreated with subsidence. Stratigraphically, the Older Sediments are followed by surficial deposits of intermediate age, consolidated Younger Sediments reworked from Older Sediments, and unconsolidated Holocene surficial deposits reworked from Younger Sediments. The most prominent structures are a northeast-trending anticline and northeast and northwest fault sets. Some deformation was Cretaceous, but folding and much faulting occurred after deposition of the Older Sediments. Remnants of plainlike features and destructional terraces on the Older Sediments attest to stepwise downcutting of the terrain during successive stages of uplift. Near the end of this process, the present valley floors and coastal headlands developed. During a probable epeirogenic rise in sea level, Younger Sediments filled the valley bottoms and an aggradational coastal plain developed. Sea level dropped by stages and with some reversals to its present position; this caused stepwise incision of the valley fill, stepwise beveling of the coastal plain, and development of the present wave-cut platform. Spilitization around the time of the Campanian orogeny caused some parts of the Nicoya complex to be calcitized and others to be silicified. Gold, pyrite, and probably additional silica were introduced during subsequent hydrothermal activity. Native gold was eroded from Nicoya Complex lodes and reconcentrated through three generations of placer gold deposits. First, the gold was deposited as a detrital.

Jan 1, 1977

By Y. C. Lo

This paper attempts to answer whether or not the mill performance at Bougainville could have, in fact, been predicted by the population balance approach, or whether other special considerations are required to explain their behavior. In recent studies, the plant tests were performed at Bougainville and batch tests were carried out at the Utah Comninution Center. In all tests power measurements were made and several levels of energy input to grinding were evaluated. Also, tracer tests were performed for mill residence time determination. The performance of Bougainville's 5.5 x 6.4 m mill has been very successfully predicted by population balance methods. The prediction errors are only about 1% on product size distribution and 4% on power with a mill volume scale-up of 3790 to 1. It is significant that this approach will reduce the risk of failure in large mill design that has been recognized in traditional methods.

Jan 1, 1987

By B. K. Parekh

Large reserves of coal pond fines are found in the Illinois Basin-over 40 million tons in Western Kentucky, over 65 million tons in Southern Illinois, and over 35 million tons in Southern Indiana. If these fines are used to produce coal-water slurry (CWS), fuel costs, NOx. emissions, and pond closure costs can be reduced. Coal fines from this region that are used to produce CWS for co-fire or re-burn may require processing, however, to attain proper particle size distribution and fuel quality. To evaluate the effectiveness of using coal cleaning technologies to control these CWS quality parameters, a simple flowsheet for recovering and processing coal pond fines was designed and tested. Coal fines processing consisted of using classifying cyclones to size at nominal minus 200 mesh, cleaning the classifying cyclone underflow using spirals, and cleaning the overflow using column froth flotation. Ash content of the dean coal from the spiral was reduced to about 10 percent, which is satisfactory to use for CWS co-firing in a cyclone-fired boiler. The clean coal from column flotation may be used for re-burn in a cyclone-fired boiler or as co-fire fuel in a wall-fired or tangentially-fired boiler. Heating value recovery during laboratory-scale, pilot-scale, and commercial-scale coal cleaning testing was about 80 percent.

Jan 1, 1998

Water contact angles in the air/water/francolite, fuel oil/water/francolite and fuel oil/water/quartz systems were measured to describe the wetting characteristics of these minerals. It was found that white francolite is more hydrophilic than black and tan francolite both in the absence and presence of fatty acid addition. The contact angle measurement results do not correlate very well with the flotation response and it appears that kinetic aspects of the bubble attachment process play an important role in the francolite-fatty acid flotation system.

Jan 1, 1997

By Roger Holmberg

INTRODUCTION The driving of drifts is a very important aspect of underground mining. It is not unusual for the percent¬age of rock broken during development in a mine using sublevel caving, for example, to be as much as 25% of the total. If one also considers the amount broken for transport, ventilation, and exploration drifts, one can easily understand that the planning and excavation of drifts play a major part in the total economics of the mine (Fig. 1). Increasing mechanization in mining demands larger tunnel areas for transport and mining equipment. With modern machines the hard work involved in using hand¬held pushers is gone, and a better environment is achieved. More rational methods could be used, but much of the experience the working man acquired by working close to the rock face (such as utilizing the natural weak planes in the rock when he placed the drill¬ing holes) has unfortunately been lost. By having sepa¬rate shifts for drilling, loading, and hauling, more atten¬tion has to be placed upon a well-designed drilling pattern. Some reduction in the number of holes required can be achieved with mechanized drilling because of the larger holes that can be produced. On the other hand, it is probably not possible to achieve the same precision as with pneumatic pushers, and it is difficult to utilize the larger holes because these cause more damage to the re¬maining rock. Recently, however, the precision has be¬come very good with the parallel booms and automatic devices for setting the lookout angle (Fig. 2). A larger arch of the drift roof requires a more carefully executed blasting procedure than before in order to prevent rock fall and to insure a sufficiently long stand-up time. In this chapter, empirical relationships that can be used to design an economic and optimal drift blasting design will be presented. The principles of the calcula¬tion method are based upon the earlier work of Langefors and Kihlström (1963) and Gustafsson (1973). COMPARISON OF EXPLOSIVES To provide for the use of various explosives it is necessary to have a basis of comparison. Several meth¬ods have been developed to characterize the strength of an explosive. Some examples are comparison of values given by (1) calculated explosion energies; (2) the ballistic mortar test; (3) the Trauzl lead block test; (4) the brisance test; (5) the weight strength concept; and (6) the underwater test. However, most of these meth¬ods should be used carefully when stating the breaking

Jan 1, 1982

By Brig M. Moudgil

It was reported earlier that francolite and dolomite from the South Florida deposits cannot be selectively floated using conventional conditioning with sodium oleate as the collector. However, dolomite could be separated from francolite if the minerals were first conditioned at pH 10 followed by reconditioning at a lower pH. An optimum separation was achieved at a reconditioning pH below 4.5. Reconditioning pH and collector concentration were determined to exert a major influence on the selectivity. Flotation, adsorption and transmission infrared spectroscopic results are presented to elucidate the mechanisms underlying the observed selectivity.

Jan 1, 1984

By Jan Wolski

Increasing interest in the Bucket Wheel Excavator (BWE) technology calls for a universally understandable definition of suitable performance factors which would reflect the unique features of this technology. The importance of properly designed and calculated performance factors for the BWE systems cannot be overemphasised. They are used by all levels of management in any mining organization for a wide variety of purposes, in particular for budgeting, for selecting new equipment, for monitoring current equipment and for comparison with other operations.

Jan 1, 1984

By M. J. Virnig, G. A. Kordosky

Throughout time, the mining industry has been very successful in meeting the world's requirements for metals and materials while meeting the challenges of decreasing ore grades and increased emphasis on protection of the environment. This success has been due to the development and implementation of new technologies. A clear example of such a development over the past 25 years is the increasing use of leaching/solvent extraction/electrowinning for the recovery of copper from oxide and sulfide ores. The key to the successful introduction of this technology was the discovery and development of the hydroxyoxime liquid ion exchange reagents by General Mills Chemicals (now Henkel Corporation). An important role was also played by the close working relationships between General Mills Chemicals and Ranchers Exploration which resulted in startup of the first plant in 1968 and between General Mills Chemicals and Bagdad Copper which resulted in the startup of the second copper SX-EW plant in August of 1970. Following on the heels of the hydroxyoxime development came the commercialization of other new chelating reagents based on different chemical functionalities, i.e., beta-diketones, alkylated 8- hydroxyquinolines and sulfonamidoquinolines. This initial spurt of activity was then followed by a slowing of development in terms of new reagent functionalities. Activity has continued in terms of further optimization/improvement of existing reagent functionalities but the commercialization of new reagent functionalities has slackened. This observation reflects the fact that the development of new reagent functionalities for metal recovery has become increasingly more expensive such that the right combination of price and sales volume must exist in order to justify the investment required to bring a new reagent to the market place. Given the dependence of the mining industry on innovation to meet the needs of the future, one can ask how these new developments, particularly in new reagents, will occur. To arrive at an estimate of the costs involved in commercializing a new metal extractant functionality, particularly a chelating type functionality, a case study of the development of LIX ®* 34

Jan 1, 1994

By J. E. Russell

The purpose of this paper is to describe an independent study which forecasts Texas coal production, specifically for electric power generation. This study, extending to the year 2000, is justified on the following basis. Texas produces and consumes considerably more electric energy than any other state, has consistently high growth rates in the population and industrial sectors, and has large lignite reserves. Also, since recent forecasts have been criticized as overly optimistic, this study is timely when considering the long lead times required in obtaining new power sources. In the study demand for electric energy was assumed to rest on two dominant factors: 1) overall state of the Texas economy as measured by the Texas Gross State Product (TGSP) and 2) Texas population. Demand models were prepared and tested following a study of several options. A final linear regression demand model with time lags for the two variables was chosen on the basis of good correlations. On the supply side, uncertainties such as impact of nuclear sources, gas-fired cogeneration, and ratio of imported to lignite coal exist. These uncertainties were studied with high and low cases for effects on lignite. Finally a simple supply model was chosen. Results of the study indicate that lignite production in Texas will rise from the current (1984) 40 million tons per year (XTPY) to the range of 77 to 124 MTPY and more probably 100 HTPY in the year 2000.

Jan 1, 1984

By Jr. Pickering

Kaolin is mined from extensive sedimentary formations in the eastern Amazon River Basin of Brazil. Production began about 25 years ago from 30 meter thick beds of ultra-fine particle clay of superior viscosity along the Jari River north of the Amazon. Operated by CADAM S.A., capacity now exceeds 750,000 tonnes per year ot high glossing paper coating kaolin product. South of the Amazon on the Capim River are two new operations: Para Pigmentos S.A. and Rio Capim Caulim S.A. The purity , and large coarse plate-shaped particles of these Capim kaolins support production of superior brightness and whiteness paper coating and filling grades. Annual capacities are reported to be 150,000 to 300,000 tonnes each, with expansions planned. Most of Amazon area kaolin production is shipped to western European, Asian, and North American markets.

Jan 1, 1999

By Takashi Goto

In 1968 three historical rockbursts had occurred at Bibai Coal Mine in Hokkaido. At the time they had been observed by several seismic observatories as natural earthquakes away more than 100km from Bibai City. These facts taught us that the occuerrence of failure yielded in underground opening that was accompanied with seismic wave could be observed by seismometer on the surface. After two years from this desaster, the study concerning to microseismic events generated from underground mining panels has been begun by researchers with heart-throb.

Jan 1, 1982

By L. K. Holder

The White King / Lucky Lass Superfund site consists of two former uranium mines in south-central Oregon. The remedy included consolidating two large mining overburden stockpiles that contained low levels of radioactivity and heavy metals by moving over 700,000 cubic yards of material and then capping the combined stockpile. An innovative armored cap design was used to minimize the stockpile footprint and thereby prevent disturbing existing wetlands. In addition, the stockpile was designed to merge into the surrounding topography. The remedy also included stream restoration and development of new wetlands. The stream was returned to its pre-mining channel, with the addition of hydraulic features to create new wetlands. The wetlands have greatly enhanced the ecological value of the remedy and the site.

Feb 23, 2014

By T. W. Beck, J. A. Organiscak

The U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has recently studied several redirected scrubber discharge configurations in its full-scale continuous miner gallery for both dust and gas control when using an exhaust face ventilation system. Dust and gas measurements around the continuous mining machine in the laboratory showed that the conventional scrubber discharge directed outby the face with a 12.2-m (40-ft) exhaust curtain setback appeared to be one of the better configurations for controlling dust and gas. Redirecting all the air toward the face equally up both sides of the machine increased the dust and gas concentrations around the machine. When all of the air was redirected toward the face on the off-curtain side of the machine, gas accumulations tended to be reduced at the face, at the expense of increased dust levels in the return and on the curtain side of the mining machine. A 6.1-m (20-ft) exhaust curtain setback without the scrubber operating resulted in the lowest dust levels around the continuous mining machine, but this configuration resulted in some of the highest levels of dust in the return and gas on the off-curtain side of the mining face. Two field studies showed some similarities to the laboratory findings, with elevated dust levels at the rear corners of the continuous miner when all of the scrubber exhaust was redirected toward the face either up the off-tubing side or equally up both sides of the mining machine.

Jan 1, 2013

By Sean Hunter

Artificial Intelligence has a long history but is currently coming strongly into focus with new advancements. This leads to questions many people are asking: what exactly is AI, how can it be used effectively in mining operations, and what foundation is required to make AI implementations successful? In mining, many AI applications exist, from drill pattern optimization to predictive maintenance. However, many implementations struggle due to data integration challenges. Mining operations generate large amounts of data from many sources, such as fleet management systems, drill sensors, process control systems, and laboratory results. Unfortunately, this data often exists in silos where it’s difficult to get it out, making AI applications unable to leverage it. Worse still, tools that use AI don’t always provide their data back to the system, creating even further data silos. All these problems make it hard to take advantage of the data at the mine, slowing down and reducing the effectiveness of AI. This paper presents a comprehensive approach to organizing mining data using an AI-ready knowledge graph system. We will first explore the evolution of AI in mining, from early expert systems to modern machine learning applications. Then, we will detail how a knowledge graph can integrate business context, operational data, and AI models into a cohesive system that enables more effective AI implementations across mining operations. The proposed method has been developed considering both the unique data challenges faced by the mining industry, while also considering best practices learned from the AI field at large. By following this approach, it’s possible to better utilize existing data, getting higher quality and more complete results faster, and in a way that’s reusable and composable.

Feb 1, 2025