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By F. J. Menzer, E. M. Schern

The Morenci/Metcalf porphyry copper mining operation, located in southeastern Arizona, currently processes approximately 91,000 tonnes of ore per day and has copper ore reserves estimated to be in excess of one billion tonnes. Functional groups within the Geology Department (currently staffed with six professional and two support personnel) include mine geology, project geology, and hydrogeology. The primary task of mine geologists is daily preblast bench face mapping with grade and mill amenability estimates. Auxiliary duties include detailed in-pit metal distribution evaluation, mineragraphic work and flux quarry geology. Project geologists conduct exploration and preliminary development projects both within and outside the Morenci district and provide support to ore reserve block modeling and geotechnical work performed by the Morenci mine engineering group. Hydrogeologists handle exploration for and development of groundwater resources and groundwater flow modeling, mine dump leach solution penetration and recovery evaluation, and tailing dam water reclamation.

Jan 1, 1992

By Omar Abd el Fattah Ramly, Abdallah Mohamed Sourour

FOREWORD In 1974, the Ministry of Housing and Reconstruction (The Client) which subsequently became the Ministry of Development and New Communities of the Government of the Arab Republic of Egypt assigned responsibility to the Arab Contractors (Osman Ahmed Osman and Company) for the design and construction of the tunnels under the Suez Canal. For this project the Arab Contractors of Cairo and Tarmac International of London formed a joint Venture, called Osmac. Sir William Halcrow and Partners of London are responsible for the design of the Ahmed Hamdi Tunnel as a Sub-Contractor to the Contractor. The advisory consultant of the client is a joint Venture between Tippetts-Abbett-McCarthy-Stratton (TAMS) of New York and Arab Consulting Engineers (ACE) of Cairo. INTRODUCTION A site investigation was carried out between Km 141 and Km 150 Suez Canal chainage to determine the ground conditions relevant to design and construction of a road tunnel under the Suez Canal. A feasibility study included aerial surveying, geological mapping and the drilling of 8 boreholes. Detailed investigation included the drilling of 105 boreholes, sampling, piezometer installation, pumping tests, and the digging of trial pits and trial excavations. In-situ work comprised SPT, permeability tests and dilatometer tests. Laboratory testing included soil classification tests, compaction tests, California Bearing Ratio tests, shear strength determination and oedometer consolidation tests as well as chemical analysis of both soil and ground water. The investigation revealed that the ground conditions at the first proposed El Shatt site (Km 148.5) were not favourable for bored tunnelling, whereas they were more favourable at the southern El Shatt site (Km 150.0).

Jan 1, 1979

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By T. M. Broderick

INVESTIGATIONS into the possibilities of economically mining and concentrating low-grade iron ores of the Lake Superior region are attract-ing increasing attention. Among the organizations that are carrying on the work are the United States Bureau of Mines, the State of Minne-sota (which spends about $80,000 annually on problems of the 'iron and ferroalloy ores of Minnesota), and the State of Michigan (which spends about $10,000 annually of its iron-ore research). Several of the mining companies are also financing research. Of the states in the Lake Superior district, Minnesota has done most in iron-ore concentration. In 1930, thirty-seven concentrating plants were in operation on the Mesabi Range, beneficiating about one-third of the total ore shipped. About one-half of these plants reduced silica; the others reduced moisture or improved the structure of the ore.1 Research into the possibilities of magnetic concentration of the Eastern Mesabi magnetite ores indicates that vast tonnages of that ore may be utilized at a profit in the not distant future. Magnetic concentration has also been tried at Sellwood, Ontario, on the Moose Mountain deposit, and at the Berkshire mine in Wisconsin on the magnetic ores of the Western Gogebic Range. There have been few attempts to concentrate Michigan iron ores. In order to determine the possibilities of such concentration, iron-ore research has been carried on at the Michigan College of Mining and Technology for the past few years. After a general survey of the iron ores of the state, a program of more detailed experimentation was out-lined, starting with work on the Ironwood formation of the Gogebic Range. The results of this research led to the belief that gravity methods will produce fairly satisfactory concentrates from the parts of the iron formation that are made up of comparatively thick alternating beds of rather high-grade ore and lean chert.

Jan 1, 1933

By D. S. Choi

Coal is expected to become an increasingly important source of energy in the future. Coal production has already increased from about 650 million tons in 2975 to about 875 million tons in 1984 (Wilkinson, 1985). The declining trend of labor productivity in the early seventies was a source of concern for Consolidation Coal Company (Consol). To improve productivity, a gradual change from room-and-pillar mining to longwall mining has been taking place within Consol. Consol produces 45 million tons of coal annually with about 70 percent of the production coming from underground mines. Consol introduced longwall mining in the early seventies and currently operates about 20 longwall faces. The longwall faces are in mines in the Appalachian region in the States of West Virginia, Pennsylvania, and Ohio. The successful operation of longwall faces has contributed to a recovery of productivity and to an improvement of mine safety.

Jan 1, 1985

By C. Musingwini, C. Beaumont

"Kansanshi mine, located in northwestern Zambia, uses conventional openpit mining to produce primarily copper, with gold as a by-product. The ore is extracted from a deposit with highly complex mineralogical suites that are difficult to process, sometimes leading to poor recoveries. The mine was using an ore classification system called ‘Mat-Type’, which classified various ore types into 22 different quality categories, ranging from poor to good quality. Ore with poor recovery was classified as ’poor quality’ ore and directed to long-term stockpiles. Due to a lack of proper integration between the technical and functional areas forming the mine value chain, Mat-Type unintentionally misclassified ore. A geometallurgical analysis was therefore undertaken to review Mat-Type and a new geometallurgical ore classification system, called ‘OXMAT ’, was developed to replace Mat- Type.When implemented, OXMAT eliminated nine of the 22 ore categories and the remaining 13 ore categories could now be more accurately and consistently defined, leading to a significant change in the quantity of ore being mined. OXMAT demonstrated that within a defined test volume of the geological model, waste tonnes could be reduced by 19% while ore tonnes could be increased by 17%. This paper therefore demonstrates the value created through integrated geometallurgical modelling. IntroductionKansanshi mine is located in northwestern Zambia, approximately 10 km north of the provincial capital Solwezi and about 160 km west of Nchanga mine in the Central African Copperbelt (Broughton and Hitzman, 2002). The location of Kansanshi mine relative to other major copper deposits in the Copperbelt is indicated in Figure 1.Kansanshi mine uses conventional openpit mining methods to exploit copper- and gold-bearing veins hosted in a structurallycontrolled mineral deposit. Mining is carried out in two areas of the deposit, the Northwest and Main pits. A third area of the deposit, called Southeast Dome, is currently not being exploited (Figure 2)."

Mar 1, 2019

By Robert J. Whiteley, Colin Parker

Two major tunnel projects with a combined value of about $US700 million have been recently completed in Sydney using both soft ground and hard rock Tunnel Boring Machines. The first of these and the main entry in Australia for the Year 2000 Olympics was the New Southern Railway. This is 10 km of mainly soft ground tunnel linking the Sydney’s International Airport with the Central Business District. The second tunnel was designed to alleviate major stormwater pollution of Sydney Harbour and involved construction of the Northside Storage Tunnel. This is19 km of hard rock tunnel at depths exceeding 90 m that connects many of the northern Sydney suburbs of Sydney with the North Head Ocean Outfall. Case studies of these projects describe the use of innovative geophysical technologies comprising gravity and seismic tomographic imaging with geotechnical testing at the feasibility and design stages. This approach minimised construction and financial risk by effectively quantifying the significant geological and hydrogeological issues along these tunnel routes that exerted major controls on these projects.

Jan 1, 2001

By Clara Godoy, Álvaro Dapía, Paulo Couceiro, Håkan Schunnesson, Juan Navarro

This paper applies geostatistical tools in Measure While Drilling (MWD)data to estimate the probability distribution of values in all the points of the studied domain in order to assess the continuity of rock classes between boreholes. The analyses carried out by Ghosh et al.(2018) and Navarro et al.(2019) have been used as starting point of this work to classify the geotechnical rock condition in four classes: solid rock, fractured rock, cave-in rock and cavity. From it, an application for the geotechnical rock condition of ore bodies have been developed, aiming at characterizing the rock before the charging the holes to minimize unexpected rock conditions and to address issues associated with charging and blasting operations. Such problems are closely related with non-optimal rock fragmentation after blasting. The procedure has been applied in the geotechnical block model results obtained from Navarro et al.(2019)’s work in the Luossavaara-Kiirunavaara AB’s (LKAB) Malmberget underground iron ore mine, Sweden. Navarro et al.(2019)’s model was developed based on102 fan-holes from five ore bodies and extrapolated to the full-scale in20 drifts with 5600 fan-holes from two orebodies. A multi-step transformation of the MWD parameters was carried out in order to minimize external influences other than the rock mass. The study shows the calculations of the variogram and kriging estimation in the 3D domain for six ring-blasts, from one of the ore bodies studied in Navarro et al. (2019)’s work to assess the continuity of the rock classes along the six ring-blasts in a 3D mapping model. For that, intermediate rings between the measured ones from the MWD have been estimated. The probability distribution of values in the entire domain of rings with measured samples has been plotted together with the rock classes identified by the blasthole paths. The results show high accuracy in the matching between the kriging and the values given by the MWD data, allowing to visualize smooth trends of different rock classes along the ring. The representation of the 3D mapping model for the six ring-blast shows clear fractured and cave-in zones developed along the drift that correspond to zones with geotechnical problems found, as from internal reports.

By Clara Godoy, Álvaro Dapía, Paulo Couceiro, Pablo Segarra, José Ángel Sanchidrián, Juan Navarro

This paper applies geostatistical tools in Measure While Drilling (MWD) data to estimate the probability distribution of values in all the points of the studied domain in order to assess the continuity of rock classes between boreholes. The analyses carried out by Ghosh et al. (2018) and Navarro et al. (2019) have been used as starting point of this work to classify the geotechnical rock condition in four classes: solid rock, fractured rock, cave- in rock and cavity. From it, an application for the geotechnical rock condition of orebodies have been developed, aiming at characterizing the rock before the charging the holes to minimize unexpected rock conditions and to address issues associated with charging and blasting operations. Such problems are closely related with non-optimal rock fragmentation after blasting.

Feb 1, 2020

By Y. C. Kim

This paper reviews the past 18 months of geostatistical work in a coal deposit performed jointly by the University of Arizona and the Homer City Owners. The objective of the study was to better predict the in-seam sulfur values of the deposit for the purpose of future emission control. Based on initially available 112 DDH information, variogram models were developed for Sulfur, Ash and Thickness for the entire deposit. The deposit was then kriged using 333 m x 333 m (1000 ft x 1000 ft) panel size. The estimation variance information obtainable from geostatistics was next utilized to improve the development drilling activities that were underway. The results of this effort are presented in this paper. In addition, this paper describes (1) the reasons for preferring kriging over the conventional isopachs, (2) the results of empirical validation of the kriged estimates using 19 additional DDH information, and (3) up-to-date experience on the use of conditional simulation of the same deposit for the future emission control strategy development.

Jan 1, 1980

By Y. C. Kim, I. K. Chopra, F. Martino

This paper reviews geostatistical work in a coal deposit performed jointly by the University of Arizona and the Homer City Owners. The study objective was to Predict more accurately the inseam sulfur values of the deposit for the purpose of future emission control. Based on initially available 112 DDH information, variogram models were developed for sulfur, ash, and thickness for the entire deposit. The deposit was then kriged using 333 m x 333 m panel size. Kriging produced better results than conventional isopachs. The estimation variance information obtainable from geostatistics was then used to improve development drilling activities that were underway. This effort was successful. Up-to-date experience on the use of conditional simulation of the deposit appears promising for future emission control strategy development

Jan 1, 1982

By Z. Kokesz

The following paper presents the results of geostatistical studies of the selected hard-coal deposits in Poland. Geostatistical methods were applied mainly to the characterization of variability structure of the coal seams thicknesses as well as sulphur and ash contents in the coals. Results imply that the accuracy of coal reserves estimations can be improved if kriging method is applied. Kriging allows predicting more precisely the values of such parameters as thickness and sulphuring content.

Jan 1, 1993

By Gillies A. D S, Just G. D

Coal washability data can be used for assessing coal quality. However, the techniques of using these data to solve quality problems differ from one mine to another and certain problems may never really be investigated due to limitations of the available techniques. One promising way to overcome these limitations is by correct application of geostatistics.A geostatistical study on coal washability data was undertaken based on a data set of closely spaced in-pit bore cores. These bore cores were analysed consistently over a relatively simple geological area. The average distance between the drill holes was about lOOm. There were 78 drill holes available for the area after deleting the erroneous bore cores. During the study, nine extra closely spaced drill holes were drilled within a single mining block.A procedure to construct two coal quality models, a kriging or cokriging model and a simulation model, was proposed. The modelling results for the data above are discussed and results of a mine scheduling exercise based on the models developed are included.

Jan 1, 1992

Geostatistical methods have become well established in the last two decades for the evaluation of ore reserves in base metal, industrial minerals, coal and gold deposits of the Witwatersrand type. However, there has been considerable debate about the applicability of geostatistical techniques when applied to vein-type gold deposits with hydro or epithermal mineralisation. The main problems stem from a lack of spatial continuity and the highly erratic sample values that characterise these deposits. This paper reviews some of the current geostatistical techniques that are applied to the evaluation of gold prospects.

Jan 1, 1992

By Harvey P. Knudsen

This paper illustrates the application of geostatistics to a roll front type uranium deposit located in Wyoming. The steps involved in calculation of experimental variograms, variogram modeling and verification of the resulting models are described in detail. The resulting spherical variogram models for grade thickness and thickness show strong geometrical anisotropies. The major axis of anisotropy for both variables is approximately parallel to the axis of the roll front and the minor axis perpendicular to the roll. This model confirms the technique of drilling "fences" across the roll front, where the drilling is much closer together than the fences along the roll.

Jan 1, 1978

By Just G. D

The results of a geostatistical analysis of geochemical data obtained from field measurements are described in the paper. Q values derived from seismic signal rise times for different travel paths in the rock masses were used in the study. Cross-hole seismic measurements made at surface and underground sites formed the basis for the work. Geostatistical estimation of average l/Q values for area of the rock were compared with geological interpretions of rock type distributions. Reasonable correlations were obtained between the two methods of rock quality estimation.

Jan 1, 1988

By Kyle L. Brennan, Scott Maybrier, Gang Chen, Scott Huang

Data from about 3200 drill holes in the offshore area at Nome, Alaska was digitized and processed. Most drill hole files have associated lithology, gold value, and blow count descriptions for each drill hole. The gold intensity was used to present the potential gold resource in the study area on the world wide web. A web page was created that gives background information on the project, descriptions about the Nome area, maps of the claim blocks that include all the normalized slices of gold deposits, and links to other relevant sites on the web. The site is located at http://mineral.uafsme.alaska.edu/nomeproject/nomehome.htm.

Jan 1, 2002

By Abdul Aziz Hanifah

A novel instrumentation and analysis technique, called GLOSTREXT method has recently been introduced for bored pile load tests in Malaysia. This technique provides an innovative and improved alternative for conventional bored pile instrumentation methods commonly practiced for the past few decades. Results for five case histories involving full scale static load tests for high capacity bored piles with both new and conventional instrumentation details placed in within the same instrumented piles are presented to demonstrate the advantages of this novel technique. Results show good agreement between the new and conventional instrumentation.

Jan 1, 2006

By W. Soetaert, P. Dhar, H. R. Kota, M. Thornhill, S. Roelants, I. V. Chernyshova

Yeast-derived bola-amphiphiles have attracted considerable attention for their applications in various industrial sectors in recent years. However, only a few studies on this class of surfactant were reported to be relevant to mineral processing applications. In this paper, one of the novel surfactants, acidic glucolipid obtained from Candida bombicola sophorolipids and modified by using Penicillium decumbens naringinase substrate has been evaluated for its interaction with chalcocite and calcite minerals because of a new Cu-ore Nussir deposit in Norway containing calcite impurity. The interaction of glucolipid biosurfactant with copper sulphide and carbonate minerals was investigated with zeta potential, adsorption and FTIR studies, and also by Hallimond tube and bench scale flotation tests using pure minerals and Nussir copper ore, respectively. The results illustrate collector adsorption and flotation of copper sulfides at neutral pH. The bench-scale flotation results demonstrate that copper sulphides can be selectively floated from carbonate and silicate gangue minerals. This study underlines the glycolipid’s high potential for its use as collector for flotation of valuable copper sulphide minerals. Keywords: Flotation, biosurfactants, adsorption

Jan 1, 2020

It has been fairly firmly established (Fisher, N. H., 1945) that the fineness of the gold in any ore deposit varies with the depth from the surface at which the deposit was formed, and, as a corollary to this, that it is dependent upon the temperature and pressure at the time of deposition. This relationship is such that, under certain conditions, the gold fineness, taken into consideration with other recognised criteria, furnishes a very sensitive and reliable guide to the relative temperature of ore formation, at least within the epithermal and the upper part of the mesothermal range.Definition of Fineness.The fineness of gold is calculated in parts per thousand and refers to the proportion of gold present in the naturally occurring metal in the lode, which is actually a gold-silver alloy, containing usually about 10 parts per thousand of base metal and up to 500 parts perthousand of silver. A clear distinction should be made between fineness and gold-silver ratio. The latter refers to the total gold and silver in the lode as determined by assay and is usually expressed as the ratio Au:Ag. Only in deposits where other silver-bearingminerals are entirely absent, which occurs comparatively rarely, can the gold-silver ratio be used as a measure of gold fineness and, in many cases, the two have no relationship. For instance, in the Edie Creek area in New Guinea, the lodes formed under shallow epithermal conditions all carry gold 500 to 550 fine, although the gold-silver ratio ranges from 1:100 to 1:1, in places in adjacent lodes.Determination of Gold Fineness.The fineness of lode gold can be determined only after it has been separated from all other minerals. Amalgamation recovers gold fairly cleanly - unless native silver is present - and the fineness of amalgam bullion is generally a reliable indication of the correct fineness of the gold. If the use of plates is involved, the bullion may be adulterated, but the effect of any copper, or other metal, that may have been introduced can be cancelled by assuming that the gold and silver shouJrl add up to about 990 fine, or by ignoring the base metal content altogether, which varies little in naturally-occurring gold, and in calculating for comparison purposes all fineness figures to the basis Au + Ag = 1,000.The composition of bullion obtained from cyanidation is generally intermediate between the true gold fineness and the total gold-silver proportion as determined by assay of mine or mill-head samples of Cyanide solution dissolves other silver-bearing minerals and the fineness of the resulting bullion is thereby lowered. Consequently, the fineness of cyanide bullion rarely corresponds to the true gold fineness and is useless for diagnostic purposes, although it is a common fallacy to refer to the fineness of cyanide bullion as the fineness of the gold.

Jan 1, 1950