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By J. Mácsik, J. Lindblom, C. Maurice, Susanne Nigéus

Using non-hazardous industrial residues in mine waste remediation is beneficial not only for the mining industry where substantial amounts of the waste generated have potential to produce acid rock drainage and pollute the environment, but also the providing industry, minimizing the waste landfilled. In this study green liquor dregs (GLD), residue from 15 different paper mills were characterized to valorize it as a potential product as a cover material. In another part of the study, one of the GLDs and a local till were characterized to determine the optimal mixture of GLD amended till to be used in a field application at the closed Näsliden Mine in northern Sweden. The study concluded 10% GLD-amended till to be the optimal recipe and was successfully applied at the Näsliden mine waste dump. However, the great variability in the characteristics of GLD creates challenges if it is to be valorized as a product.

Dec 7, 2023

By RALPH BALTES, AMIR EHSAN KIANFAR, FABIAN UTH, ELISABETH CLAUSEN

As indoor positioning provides particular challenges due to the unavailability of GPS signals, various systems such as ultrawideband (UWB), radio frequency identification (RFID), ultrasound, and wireless local area network (WLAN) have been proposed in recent years. Some of these technologies are currently being marketed and some are still being developed. UWB technology allows for higher precision while also reducing power consumption. Hence, the underground automation and localization systems can use this technology for more accuracy and robustness. This article discusses new robust UWB modules used for underground positioning and collision avoidance with regard to human safety in underground mining operations.

Jul 31, 2020

By F. Dahl, P. Raleigh, J. Holzhauser, B. Nilsen

Tunnel excavation using tunnel boring machines (TBMs), has become increasingly common in recent years, despite the fact that precise evaluation of certain risks have not kept pace with the use of these machines. One of the risks easily overlooked by Engineer and Contractor alike are the effects of abrasive ground on the costs and schedule of a given project. The impacts of worn and damaged TBM cutter heads have been observed on hundreds of tunnel projects around the world. It would appear that a reliable prognosis of the abrasiveness of soils on a project would be of great importance for designers, clients and contractors alike. Several well acknowledged test and prognosis methods already exist for rock, however there is only very limited knowledge available to describe the abrasiveness of soil and its impact on soft ground TBMs. This paper will examine approaches to this problem and suggest a new approach based on a current project undergoing design.

Jan 1, 2007

By S. K. Kawatra, J. A. Halt

"Low-grade iron ores are finely ground and processed to recover iron-bearing minerals. However, the iron-rich powder is too fine to be used directly in blast furnaces and most direct reduction furnaces, and must be agglomerated or pelletized into a usable product called “pellets.” Bentonite clay has traditionally been used as a binder to make iron ore concentrate pellets, but it is expensive and contaminates the pellets. Organic binders may be a viable alternative to bentonite clay. This manuscript reviews organic materials that have been used to make iron ore concentrate pellets. Included are discussions on the development of organic binders, common pros and cons to organic binder use, organic binder structure and its effects on agglomeration, and additives to organic binders.IntroductionIron ore agglomeration turns finely disseminated, low-grade iron ores into a usable product, called pellets. During pellet production, fine-grained, iron-rich minerals are liberated from low-grade ores, concentrated, and agglomerated into round balls that are thermally hardened or cold-bonded to form pellets. Pellets are then transported to blast furnaces or direct reduction operations where they are used to produce iron; iron is further refined and shaped into the wide variety of steel-based industrial and consumer products in use today.Over the years, pellet production has become increasingly more prevalent with the increased exploitation of low-grade iron ores and increased iron and steel consumption around the world. In 2010, world iron ore pellet production was 388 Mt. It could be argued that the current pellet production process has been enabled by the use of binders – practical experience has shown that it would be nearly impossible to agglomerate iron ore concentrates using rotary drums and discs without using a binder."

Jan 1, 2015

By M. Ralchenko, C. Samson, M. Svilans, C. Walsh

"Through-the-Earth (TTE) radio has been proposed as a means of emergency communications in mines. The propagation of a TTE radio signal depends chiefly on the subsurface conductivity distribution. Robust forward models of signal propagation can be computed based on a realistic conductivity estimate. These models can be used, for example, to optimize frequency, estimate signal range, identify zones of anomalously strong or weak signals, or to optimize the position of the above-ground TTE radio unit. A method was developed to determine the conductivity distribution of a mine overburden using TTE radio transmission data. At multiple locations in an underground test mine, we recorded a wideband electromagnetic signal, spanning a frequency range of approximately 500 to 8,500 Hz, transmitted from a vertical magnetic dipole at the surface. Using a finite-difference time-domain forward modeling code, a layered Earth conductivity model that accounts for topography was fitted to the observed data, which minimizes the difference between the calculated and observed attenuations for each transmitter-receiver pair, for each frequency of interest. Introduction and objectiveThrough-the-Earth (TTE) radio has been proposed for emergency underground communications. The most common type of TTE radio is based on the transmission and reception of signals by electromagnetic induction. These signals are in the extremely low to very low frequency range — in practice, between 400 and 9,000 Hz. This technology was historically developed for mine safety, although recently other applications have been suggested, such as communications in civilian infrastructure like high-rise buildings or tunnels, in the military, and even for wireless detonation and activation. In a coal mine, which is a setting of particular importance for TTE radio due to the higher risk of accidents, day-to-day communications can be done through a wired link. High-frequency line-ofsight systems, whose signals cannot penetrate rock, are also used for communications from nonfixed points. Another option is a leaky feeder system, which is a permutation of a line-ofsight system and a wired link, where a partially shielded coaxial cable allows the signal to “leak” (Delogne, 1982). In an incident such as a mine collapse or explosion, a TTE radio system can still provide a communication link, as wired systems can be severed, and line-ofsight systems cannot penetrate through collapsed portions of the mine, or to the surface (Forooshani et al., 2013; Yarkan et al., 2009)."

Jan 7, 2018

By A. A. Dor

Recent developments in the design of concentration plants have reflected the increased recognition that has been given to the economic and metallurgical advantages of autogenous grinding. This has manifested itself in the increasing adoption of primary auto genous grinding in iron ore 'beneficiation plants in North America. Table 1 lists eleven major iron ore beneficiation plants which have either been put in operation since 1961 or are under construction at present. Seven out of these eleven plants have adopted primary autogenous grinding. Four of them have coarse grinding mills (8 to 14 mesh) and three have fine grinding primary circuits (48 to 65 mesh). Their nominal capacity totals 26. 2 million ltpy of concentrates or pellets, representing very nearly 75% of the aggregate capacity 135. 3 million ltpy) of the eleven concentrators listed. For a long time there was a tendency to consider that primary autogenous grinding was only applicable to suitable coarse grained ores, However, extensive testing of a very wide variety of ores, and actual operating performance in several commercial plants, seem to have established beyond reasonable doubt, that the majority of mineral ores which the beneficiation engineer may be called upon to process can be ground autogenously. The basis for the selection of autogenous or conventional grinding mills, becomes principally economic and depends on the liberation characteristics of the ores under consideration and their relative hardness and grindability.

Jan 1, 1965

By Daniel M. Flanagan

"Editor’s note: Each year, Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals & Aggregates Division technical committee chair and vice chairs, and to the authors of the individual commodity profiles. Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor.Joe Garska, member SME, of Imerys, is chair of the Industrial Minerals &Aggregates Division’s Technical Committee.The technical committee vice chairs include:• Hyunjung Kim, member SME, of Chonbuk National University, agricultural materials.• Xihui Lin, member SME, of Kemira, ceramics and refractory materials.• Nikhil Gupta, member SME, of Virginia Tech, chemical raw materials.• Adam Rodriquez, member SME, of Penn State, construction aggregates.• LeDeana Roberts, member SME, of Imerys, fillers and pigments.• Harsha Kolla, member SME, of ChemEOR, sorbents, filters and process aids.• Edgar Blanco, member SME, of FLSmidth, specialty minerals.Their help makes possible this July industrial minerals issue. On behalf of ME readers, the editors thank them.During the past 25 years, U.S. ball clay production (the quantity sold or used by domestic producers) increased from 788 kt (869,000 st) in 1990 to an alltime high of 1.31 Mt (1.44 million st) in 2003 (Fig. 1). Housing construction within the United States, a leading market for ball clay-based ceramics and sanitaryware, began to decline in 2005, which resulted in a considerable decrease in sales of ball clay that continued through the 2008-2009 economic recession. After bottoming out at 831 kt (916,000 st) in 2009, ball clay production steadily increased through 2015 (Fig. 1). Estimated sales in 2015 were 36 percent higher than those in 1990 and 18 percent lower than those in 2003.Four companies (H.C. Spinks Clay Co., Imerys S.A., Old Hickory Clay Co., and Unimin Corp.), mined ball clay in five states during 2015. An estimated 1.7 Mt (1.18 million st) of ball clay valued at an estimated $47.5 million was sold or used by U.S. producers, a 4-percent increase from 1.03 Mt (1.14 million st) valued at $45.2 million in 2014. Approximately 65 percent of total ball clay production was air-float, 25 percent was crude or shredded and 10 percent was water-slurried"

Jul 1, 2016

By R. G. Johnston

Minerals have many uses in paint systems. These roles include use as primary and extender pigments, sheen control, film durability enhancement, and rheology control. These and other uses of minerals in paints, and the effects of mineral quality variations on coatings performance are discussed. As coatings performance requirements become more demanding, tighter consistency of important mineral properties, such as particle size distribution and purity, is becoming increasingly vital. Future directions of mineral use to meet projected environmental restrictions and performance demands on coatings, including the use of advanced minerals technologies, are examined.

Jan 1, 1993

The 32nd annual American Hall of Fame Awards Banquet and Fundraiser, sponsored by the Mining Foundation of the Southwest (MFSW), will be held at the JW Marriott Tucson Starr Pass Resort & Spa on Saturday, Dec. 6, 2014. Each year, one living Hall of Fame inductee, up to three Medal of Merit recipients, honorees from mining?s past, and recipients of an Industry Partnership Award and a Special Citation are recognized for their respective contributions to the mining industry. Armine Frederick Ban?eld Jr., past chairman and founder of Mintec, Inc. located in Tucson, AZ, will be honored as the 2014 Hall of Fame Inductee at the awards banquet. Banfield founded Mintec from his Tucson apartment in 1970 and expanded it to a global operation. Under his guidance, Mintec won the 2013 President?s E-Award for Exports ? the highest recognition any United States company may receive for making a significant contribution to the expansion of U.S. exports. Medals of Merit will be awarded to Corale L. and James A. Brierley, founder and principal of Brierley Consultancy LLC; David Nicholas of Call and Nicholas Inc. and Scott M. Shields of Joy Global. The Brierleys are being recognized for their true scientific partnership with parallel achievements in academia and in business development. Nicholas is being recognized as the co-founder of Call & Nicholas and for his noted expertise in mining geotechnical engineering. Shields is being recognized for his innovative work with GPS integration and for playing a key role in laying the foundation for autonomous mines of the future. As representatives of mining heritage, the Hall of Fame will induct Patrick E. Connor, ?Father of Utah Mining,? for pioneering mineral exploration efforts in Utah; Earl Tappan Stannard, president of Kennecott Copper Co., for transforming Kennecott in to one of the largest U.S. copper producers; Arthur Barrette Parsons, mining editor and author, for his book ?The Porphyry Coppers in 1933,? a seminal work detailing the history and technical information regarding major porphyry copper deposits and Ernest R. Dickie, general manager of Bagdad Copper Co., for his foresight in converting the mine from block caving to open pit. The Industry Partnership Award will be presented to Empire Southwest, a third generation family owned dealership for Caterpillar which consistently ranks among the top Caterpillar dealers worldwide. A Special Citation will be presented to employees of Rio-Tinto-Kennecott Bingham Canyon Mine for their speedy recovery from the massive Manefay slope failure in 2013.Early sponsors include Ames Construction, Asarco LLC; Brierley Consultancy LLC; Caterpillar Inc.; Click Automotive Team; Deconcini McDonald Yetwin & Lacy, P.C.; Empire Southwest; Florence Copper Inc.; Freeport-McMoRan Copper & Gold Inc; Independent Mining Consultants Inc.; Joy Global Inc.; Komatsu America Corp.; Liebherr Mining Equipment; Lowell Copper Ltd.; M3 Engineering & Technology; Modular Mining Systems Inc.; MWH Global; Newmont Mining Corp.; Ram Enterprise; Rio Tinto/Kennecott, Sonoran Process Equipment Co.; Southwest Energy LLC and SRK Consulting. MFSW is a nonprofit organization and its mission to promote the value of the industry to our community and profession to ensure its future success. Funds raised from its annual banquet are principally designated to support the foundation?s education program, a partnership with the Lowell Institute for Mineral Research at the University of Arizona.

Resolution Copper Mining LLC (RCML) is currently in a Pre-feasibility study evaluating a large and deep copper and molybdenum deposit in the historic mining district east of Superior, Arizona. Work scheduled for the next several years includes dewatering the existing shut-down mine (the Magma Mine) and sinking an exploratory shaft to 2,130 meters (7,000 feet) below the surface. To dewater the Magma Mine and sink the exploratory shaft, RCML must extract and manage about 2 billion gallons of accumulated mine water inventory, as well as about 300 million gallons per year of new inflow. In order to conserve a valuable water resource in a desert environment, RCML worked with the New Magma Irrigation and Drainage District (NMIDD) to provide treated mine water to blend with and supplement the NMIDD?s water supply to approximately 2,000 hectares (5,000 acres) of farmland located east of Phoenix. A 44 km (27-mile) pipeline was needed to convey the treated water. It was essential that a treatment system be used which could reliably meet irrigation water quality goals, produce a non-scaling effluent to maintain pipeline flow capacity, and generate a dense sludge minimizing disposal cost and volume. This paper describes the resulting mine water treatment and recovery system (MWTS) and how the system has performed against objectives.

Jan 1, 2011

By Rick Frechette, Greg Nelson

"The 2018 Elko Roundtable was held at the Red Lion in Elko, NV on March 15, 2018. The gracious host was once again Knight Piésold. Attendance was robust with representatives from more than 14 mining properties across Nevada representing nine corporations. Total attendance was at its highest in almost a decade. A high level of interest was also gauged by the number of companies with multiple attendees.The topic of water in mining was clearly a factor in creating the large show of interest. In terms of industry trends that are tracked annually, this topic had been absent from the list for more than 10 years (Deloitte, 2018) but was squarely planted there this year. And deservedly so. Three attending companies are signatories of the International Council on Mining and Metals (ICMM) which espouses a firm stance on water stewardship (ICMM, 2017).How’s the water?It is reported that water scarcity affects more than 40 percent of the world’s population (Deloitte, 2018). Consumption of water in the United States, based on the last detailed census, entails only 1.5 percent usage by the mining industry. The largest users are reportedly thermoelectric power and irrigation, combining for more than 75 percent of the U.S. consumption. During the prior census period, water usage at mines was up dramatically (USGS, 2014).Mine water source usage is primarily a mix of ground water and saline or fresh surface water resources. Over the previous period, saline sources experienced the greatest percentage in growth as a mine water source, nearly doubling in use. Nevada ranks second as a state nationally in mine water consumption. California is the leader, and Nevada is immediately followed by Utah and Alaska (USGS, 2014).Water rights in Nevada and the ongoing litigation at the state level, particularly over the Humboldt River basin, have elevated the concern over the supply of water and have raised the interest regarding the topic of water across the mining industry as well as within other industries.The Elko Roundtable meeting began with a safety share and introductions, and included each attendee mentioned a water problem or solution that he or she would like to discuss during the day. An interesting list of subtopics was developed from this round robin and yielded the following most common themes:• Mine pit dewatering during operation and pit wall stability.• Draindown from tailings dams and heap leach pads and dealing with this at closure.• Post closure pit lakes, pit lake water quality and associated water rights."

Dec 1, 2018

By Peter B. Knuckey

1, Introduction Location Kalengwa mine is located in the North Western Province of Zambia, 402 kilometre by unpaved road to the west of Kitwe, which is roughly in the centre of the Zambian Copperbelt, well known as one of the world's centres of copper mining. Its position is illustrated on the map of Africa in Figure 1 and on the map of Zambia in Figure 2. It is a mine of Roan Consolidated Mines Limited whose other properties, Mufulira, Luanshya, Chambishi and Chibuluma Mines, are all located on the Copperbelt. It is managed by the Chibuluma Division of the company. The rate of production from Kalengwa will vary from 12 000 to 17 000 tonnes of saleable copper a year over the next six years. Kalengwa did not exist as a place until the first prospecting parties and later the mine became established and the early working population was recruited entirely from small villages in the surrounding area as much as thirty miles away. The mining area consists of fourteen mining locations amounting to 3.35 square kilometres and the land may be used for any purpose connected with mining, including housing, wood cutting and other utilities. The whole area is, except for minor undulations, a fairly flat plateau with main rivers running from north to south and flood basins known as "dambos" located in a general east west direction. Vegetation is, with the exception of the grassy dambos, temperate forest with relatively light undergrowth. Game of great variety is prolific, as is the associated tsetse fly.

Jan 1, 1971

By Raymond A. Bradbury

A significant news item appearing in a coal mining journal in November 1969 stated simply that a Caterpillar D-333-CNA engine had received Bureau of Mines Schedule 31 approval. This item occurring at the time a new mining property in Martin County of East Kentucky was being prospected and prepared for mining, resulted in the manage-ment of Martin County Coal Corporation asking the question, "Why not use diesel equipment in our new operation?" Martin County Coal Corporation is part of the A. T. Massey Coal Company, Incorporated organization. The property being developed is on a 17,500 acre leasehold obtained from Pocahontas Land Corporation and lies in the Wolf Creek area of Martin County. The Norfolk and Western Railway Company built a 24-mile railroad into this undeveloped section of Kentucky to tap a huge reserve of steam coal. Duke Power Company is the customer who will take all of the production from Martin County Coal Corporation mines which ultimately is projected to be 2,000,000 tons annually. Four coal seams, all above drainage, are included in the lease. The Middle Coalburg and Stockton are being deep mined now and it is in those mines that the diesel haulage equipment was introduced. This paper will endeavor to trace the steps loading to the introduction of the first diesel-powered Wagner Mining Equipment Company ScoopTram in a coal mine in America. It will further elaborate on the features which make this unit a very versatile and useful utility unit as well as the safety features which are incorporated in the machine. The success of this first unit led to the placing of

Jan 1, 1972

By Deniz Akbay

The strength of rocks and soil is a crucial design parameter in engineering projects, and it can be determined through various test methods such as uniaxial compressive strength, tensile strength, and shear strength. The point load index test is a popular indirect test method for predicting the uniaxial compressive strength of rocks. However, the reliability of the point load index’s estimation of uniaxial compressive strength of rocks is questioned due to the wide range of coefficients that are used to predict uniaxial compressive strength of rocks using point load index values. Factors such as the shape and type of rock specimen, practitioner, and test apparatus used can affect the accuracy of the point load index test. This study investigated the effect of four different specimen shapes used in point load index test (diametral, axial, block, and irregular lump tests) in predicting the uniaxial compressive strength. The rock samples were tested using four test procedures which are called diametral, axial, block, and irregular lump tests. The results showed that the irregular lump test was the most accurate in predicting uniaxial compressive strength, with the highest correlation coefficients and lowest mean absolute percentage errors. The point load index test can be used as a reliable predictor of uniaxial compressive strength of rocks when the irregular lump test is preferred.

Oct 18, 2023

By C. Alexander

Stillwater Mining Company is developing a second underground palladium and platinum mine approximately 21 km (13 miles) west of their existing Nye operation in south central Montana. A 5650 meter (18,550-foot) tunnel is required to gain access to the ore bearing horizon (J-M Reef). Access and primary mine development can be accelerated through the use of two 4.6 meter (15-foot) diameter tunnel boring machines (TBM). One TBM was purchased new while the other was purchased used. Machine specifications, site support facilities, portal/launch chamber construction, TBM assembly, startup and operation are discussed in this paper.

Jan 1, 1999

By John Hillman

The reconstruction of the British mining industry which began shortly after nationalisation in 1947 continued until well into the 1950s with the support of the Government. This support diminished as plentiful supplies of cheap oil from the middle East made many coalmines un¬economic. The planned rundown which followed was foreshadowed in the 1965 White Paper which outlined the financial measures to speed the closure of uneconomic collieries. The decline appeared likely to continue into the 21st century as the role of coal in UK energy requirements became less and less significant. This policy was well on course in 1973 when the oil crisis led to a complete reappraisal of the position. A Government examination in 1974 of the coal industry then supported the National Coal Board's general strategy of major capital investment as set out in its 'Plan for Coal' (1). Plan for Coal aimed at halting the intended decline in the industry's capacity and restoring it to 120 million tons of deep mined output in 1985. The Plan proposed action along the following lines (a) increase output by major Investment in construction at existing collieries with sufficient reserves to give 13 million tons per annum extra output (b) invest in extending the life of existing collieries by gaining access to additional reserves, to give 12 million tons per annum extra output © by sinking new mines, produce an extra 20 million tons per annum. Figure 1 shows the contribution (2) expected from each of the three sources up to 1990/1. The measures taken were expected to offset the inevitable exhaustion of existing pits and provide the additional 40-42 million tons capacity needed to restore annual output in 1985 to 120 million tons. Parallel to this programme for expansion of deep mined output, opencast mining was to produce 10-15 million tons per annum. A recent review however, indicates that new mines are likely to yield only 10 million tons per annum by 1985, mainly owing to the need for public inquiries into proposals for new mining and the resultant fact that planning approval takes 'much longer than originally expected. Nevertheless the objective of 120 million tons deep mined output by 1985 is still considered achievable of means of a greater contribution from existing mines. This programme was originally estimated to cost 2,-56 million dollars at March 1974 prices, out revised estimates of the cost of Plan for Coal indicate that it may now exceed 6,960 million dollars at mid-1977 prices. Plan for Coal includes a substantial investment in new and reconstructed coal preparation plaints. At mid-1977 prices more than 322 million dollars Ls so be invested in coal preparation projects in the UK, at the rate of, about 70 million dollars a year. This rate 3f capital expenditure has been maintained over the past three years and covers investment in a wide range of coal preparation coals for the power station, coking and domestic markets.

Jan 1, 1978

By JESSICA W. A. AZURE, Samuel Frimpong, AZUPURI G. A. KABA, FORSYTH A. KADINGDI, PROSPER E. A. AYAWAH

This study developed machine learning (ML) models for predicting rock formation reactive forces experienced by a hydraulic shovel bucket during excavation. To do this, rock formation in the form of muckpile was modeled as granular ball elements in three-dimensional particle flow code (PFC) using linear bonding logic. A typical field-size hydraulic shovel bucket modelled in AutoCAD was used to excavate the rock formation and the three-dimensional shovel bucket resistive forces required to cut through the rock formation were measured and recorded. The experiments involved different muckpile height, bulk densities, repose angles, and average fragment size. Six ML algorithms, artificial neural network (ANN), K-nearest neighbor (KNN), linear, random forest (RF), regression tree (RT), and support vector machine (SVM), were evaluated on their ability to predict the shovel bucket resistive forces. The input variables used for the prediction of the resistive forces were the muckpile bulk density, angle of repose, height, and fragment size. The results showed that the ML techniques are useful and reliable methods of predicting rock formation resistive forces based on the rock formation properties. This research is a preliminary step towards developing reliable models for accurate prediction of excavation forces/torques which could potentially enhance hydraulic shovel process automation.

Sep 27, 2021

By Richard H. De Voto

The McDonald gold project and two satellite gold deposits near Lincoln, MT were discovered in the early 1990s. They contain at least 307.9 t (9.9 million oz) of gold and 933 t (30 million oz)of silver. The McDonald gold deposit alone contains 223.9 t (7.2 million oz) of gold reserves that can be open-pit mined and processed by cyanide heap leaching at a projected cash operating cost of $6.10/g ($190/oz). The deposit is predominantly oxidized with no chance of acid production. It can be mined, operated and reclaimed with minimal permanent environmental disturbance other than the creation of an open-pit filled with a fresh-water lake that would support trout.

Jan 1, 2000

By Michael S. Zhdanov

One of the major problems of mineral exploration is the ability to reliably distinguish between uneconomic mineral deposits and economic mineralization. While the mining industry uses many geophysical methods to locate the mineral deposits, until recently, there was no reliable technology for mineral resources identification and characterization. The main goal of this project is to develop a new geophysical technique for subsurface material characterization, mineral exploration and mineral discrimination, based on electromagnetic methods. The proposed new technique is based on examining the spectral induced polarization effects in electromagnetic data using the modern distributed acquisition systems and advanced methods of 3-D modeling and inversion. The recovered parameters of the relaxation model will be used for the discrimination of different rocks, and in this way will provide an ability to distinguish between uneconomic mineral deposits and zones of economic mineralization using geophysical remote sensing technology (Zonge, 1976). The proposed research and development is undertaken using multi-partner collaboration between the University of Utah, four major mining companies, Kennecott Exploration, BHP Billiton World Exploration Inc., Placer Dome Inc., Phelps Dodge Exploration, and Zonge Engineering Inc., which is equipment manufacturer and service provider to the mining industry. The multi-partner collaboration between the academic institution, the University of Utah, and mining industry helps to identify the appropriate mining target and conduct the field experiment for practical demonstration of the developed new technology, which is an important part of the this project.

Jan 1, 2005

By Barton G. Stone

"Sampling is the process of taking a small portion of an article such that the consistency of the portion shall be representative of the whole," (Baxter and Parks, 1939)."An orebody is a mixture of minerals in proportions that vary in different parts of the mass. As a consequence, the proportion of contained metals also varies from place to place. Therefore, a single sample taken in any particular place would not contain the same proportion of metals as does the orebody as a whole except by a highly improbable coincidence."The probable error, which would be very large if only one sample were taken, decreases with the number of samples, but it never disappears completely unless the samples are so numerous and so large that their aggregate is equal to the orebody itself, in which case the orebody would be completely used up in the process of sampling."Since carrying sampling to such an extreme would defeat its own purpose, some probable error is always present in actual cases and the practical objective is to reduce this probable error to allowable limits. This means balancing the number of samples against the desired accuracy; if there are not enough samples the result is unreliable; if there are too many, the time and expense of taking them is excessive." (McKinstry, et al., 1948).In an actual orebody, the accuracy of sampling depends not only on the number of samples but also on their proper distribution throughout the orebody, for it would obviously be incorrect to take all of the samples either in a rich part or a lean part. Therefore, it is important to select the places in such a way that all parts of the orebody will be represented."

Jan 1, 2014