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By E. Varouchakis

Spartan Spatial Random Fields (SSRF?s) provide a new geostatistical framework (Hristopulos, 2003) with applications targeting environmental risk assessment and natural resources estimation. SSRF?s have the ability to incorporate constraints based on physical laws in the statistical description and have proved to be computationally fast in the analysis of synthetic data sets. This paper presents an application of a specific SSRF model and a new local-error spatial estimator (Hristopulos, 2005) in the mapping of environmental pollutants using a real data set. A detailed comparison of the local SSRF estimator with a classical kriging method is presented. It is shown that the SSRF approach provides a competitive alternative for spatial estimation.

Jan 1, 2005

By Edward C. Spalding

The mineral estate of Arizona's State Trust lands, which are administered by the State Land Department for the benefit of the common schools and 14 other beneficiaries, totals more than 10.5 million acres, or almost 15 percent of the State's entire area. Trust lands exist in all 15 of the State's counties, with the most and least acreage found in Yavapai and Gila Counties, respectively. Revenues derived from the Trust mineral estate include royalties, rentals, and fees. In Fiscal Year 1983-84, these revenues amounted to $4.2 million, or 13.5 percent of all income received by the Trust during this period. Industrial minerals, led by sand and gravel, contributed $1.1 million from 82 active properties.

Jan 1, 1987

By Donald P. Richards, Patrick Ramond, Martin Herrenknecht

Phase 1 of the second line of the Cairo Metro includes approximately 5.83km, of double track tunnels excavated in water bearing sand of the Nile flood plain. Closed face bentonite slurry shield tunnel boring machines 9.43m in diameter were used. State-of-the-art technology was used in TBM operations and guidance, with surface settlements averaging less than 14mm, and alignment deviations averaging less than 25mm. Production rates up to 580m/month were achieved, with average production of 4.8m/shift, 13.4m/day and78m/week. The completed tunnels, lined with precast concrete segments, are completely watertight under 20m of water pressure.

Jan 1, 1997

By Gabriel E. Zárate, Juan C. Guzmán

In Chile there are significant amounts of gold in flotation tailings that could be recovered, being heap leaching the most promising alternative. In order to determine the feasibility of treating these tailings by this method, a detailed study is carried out using 4 representative samples. After defining the best conditions an economic evaluation is done for a plant treating 200 tpd, sensibilizing with respect to parameters such us gold price, tailing grade and capital costs. The results show that it is technically feasible treat these gold tailings by heap leaching with gold extractions over 70 %. It is also economically feasible for gold grades higher than 0.5 g/t and gold prices over 350 US/oz.

Jan 1, 1987

By J. Vaino Huhta

An exploration program which covered an area of about 17 000 km2(6564 sq miles), was carried out between 1966 and 1969 by the United Nations project named "Mineral Survey of the Azuero Area." The target became Cerro Petaquilla, Province of Colon, Panama. See Fig. 1. Regional exploration led to discoveries of many geochemical anomalies and minor mineralization, but it was only toward the end of the project that a promising target was indicated by a large zone of comer and molybdenum anomalies in stream sediments in a remote 1, area between the Cordillera and the Caribbean coast. Follow-up surveys established the presence of porphyry-type copper mineralization in the area now known as Cerro Petaquilla.

Jan 1, 1991

By A. C. Noble

Ore reserves are often less than 30% of the geologic resource estimates initially prepared by exploration geologists. Differences of this magnitude can lead to serious problems in the early valuation of properties when the geologic resource estimates are interpreted to represent ore reserves but are later found to be misleading and gross overstatements of the actual ore tonnages. The geologist can avoid such difficulties by considering the implications of mining, metallurgical recovery and economics early in the project and by using appropriate qualifiers in the resource statement. Examples using typical deposit characteristics are used to demonstrate how the cutoff grade, stripping ratio, dilution, mining extraction and metallurgical recovery affect ore reserve estimations.

Jan 1, 1994

By David L. Moffatt, Leon Peters

A unique electromagnetic pulse sounding system for the detection and identification of geological and man-made anomalies which represent hazards in hard rock rapid tunneling operations is described. The main features of the system including a periodic video-type pulse interrogating signal and a probe structure that permits operational modes which either "see" or are "blind" to homogeneous-type targets are reviewed. The results of experimental pulse measurements on targets buried in the overburden and in a limestone medium are presented. Since the electrical properties of limestone are not radically different from those of a hard rock medium, conclusions based on these data should be valid for a hard rock media also.

Jan 1, 1997

By V. Canby

Introduction Located in Russia’s Chukotka Autonomous Region near the Arctic circle and 425km from the seasonal port of Pevek (population approximately 4600), Peschanka (or ‘Anyui’) is perhaps the world’s most isolated CuMoAu porphyry deposit of significant grade and tonnage. In addition to its extreme remoteness (66°36'N/164°30'E) and lack of developed infrastructure, Peschanka is located in one of the world’s coldest regions, with annual average temperatures well below freezing. Soviet exploration up to 1985 defined four zones with inferred resources of roughly 940Mt @ 0.51% Cu, 0.42 g/t Au, 1.4 g/t Ag and 0.019% Mo (1).

Jan 1, 2007

By P. F. R. Altounyan, I. W. Farmer

Groundwater freezing was used to stabilise 8m thick beds of saturated and weakly cemented sands at a depth of 170m, during driving of twin 1 in 4,5.2m o.d. circular drifts from the surface to the Coal Measures through 600m of Permo-Triassic strata. Instrumentation was installed during erection of the lining in frozen and unfrozen ground to measure ground and groundwater pressures on the lining and ground temperatures up to lm into the frozen ground. Observations showed that following thawing, effective lining stresses in the frozen zone were low, indicating minimum strata disturbance during freezing and subsequent machine excavation. Groundwater pressures were lower than expected.

Jan 1, 1981

By J. L. Yordan, T. Hilderbrand, R-H Yoon

High brightness clays are produced from Georgia kaolin by flotation. Fatty acids are used commonly as collectors for anatase, which represents the major colored impurity in the crude. This process requires activation of the minerals with divalent cations such as Ca2+, in which case proper control of the activation step is crucial to the success of the flotation process. In the present work, laboratory tests have been conducted using alkyl hydroxamates as the collector for anatase. A major advantage of using hydroxamate is that this new collector requires no activator. The laboratory tests show also that the hydroxamate collectors produce consistently better products with higher yields from a variety of kaolin clays.

Jan 1, 1994

By M. Galetakis, C. Roumpos

A sustainable coal industry needs to achieve a number objectives concerning mainly with superior utilisation of deposits and improved environmental performance. Modern quality control systems, which are greatly based on the on-line analysers, play an important role in achieving sustainability targets. This paper discusses the testing and application of on-line ash analysers installed in the Ptolemais and Megalopolis lignite mines in Greece and examines the possibility of using this type of analyser to control blending and homogenisation operations. The effect of the accuracy of on-line analyser to control process, when used for the characterization of low rank coals with complex and variable composition, such as greek lignites, is examined.

Jan 1, 2005

By W. D. Presley, T. R. Harrell

This paper will be a case history of the shaft and tunnel concrete lining techniques used at the Rocky Mountain Pumped Storage Project located in northwest Georgia. Emphasis will be placed on the shaft lining techniques with only a brief description of the tunnel concrete lining techniques. The 10.67 meter (35 foot) diameter shaft and tunnel concrete linings are 0.61 meter (2 foot) nominal thickness with a single row of reinforcing bars. The tunnel was placed in 18.29 meter (60 foot) lengths with bulkheaded end sections. The 172.72 meter (566.68 foot) vertical shaft was placed in 3.05 meter (10 foot) high sections using jump forming techniques.

Jan 1, 1985

By Gary A. Almeraris, Thomas F. Peyton

This paper describes the innovative procedures employed during the construction of 3 deep shafts within the confines of New York City. The shafts, which varied in diameter from 1.8m (6ft) to 7.3m (24ft) and had an overall depth of 199m (650ft), were excavated by both mechanical and conventional methods. These were subsequently concrete lined, clad steel riser pipes installed and associated surface structures were constructed. Tricky surface rock blasting coupled with the unearthing of unexpected obstructions caused constant uncertainty during the excavation phase. In addition, the necessity of handling men and material in restricted yet deep openings required the development of a safer and more productive shaft construction procedure.

Jan 1, 1989

By John T. Crawford

Various open pit limit-analysis techniques have been utilized for many years to design pit limit surfaces. In the last 15 years there have been many advances in developing sophisticated computer methods to aid this process. The extensive capability of the digital computer has led to effective utilization of multiple alternative approaches to problem solving. Computerized open pit limit analysis methods can be applied to a broad scope of long range and intermediate range mine planning and design needs. This paper provides an overview of some of the more important of these applications. While not covered in detail, they are meant to indicate the flexibility and adaptability of open pit limit analysis methods and to stimulate thought.

Jan 1, 1979

By S. Barkhoudarian, R. R. Gupta, R. F. Steinberg

A study of the feasibility of using acoustic signals to detect discontinuities ahead of excavation has shown that reflecting interfaces in a homogeneous rock can be easily identified. Moreover, discontinuity interfaces in a very complex field site (where the rock face was weathered, was full of jointed rocks, and had a destressed zone running along the mine walls) could be identified with a reasonable level of confidence, using a cross-correlation technique for signal processing. The results of this study go a long way toward proving the feasibility of the technique. However, further development work is needed to optimize an operating system in a hard rock environment where boring machines are used for excavation.

Jan 1, 1997

By K. H. McDaniel

Eight mine weather stations (MWSs) installed at the Waste Isolation Pilot Plant (WIPP) to monitor the underground ventilation system are helping to simulate real time ventilation scenarios. Seasonal weather extremes can result in variations in the natural ventilation pressure (NVP), which can significantly affect the ventilation system. The eight MWSs, which previously collected and stored temperature, barometric pressure and relative humidity data for subsequent NVP calculations, were upgraded to provide continuous real time data to the site-wide central monitoring system. These data can now be utilized by the ventilation engineer to create real time ventilation simulations and can indicate trends that assist in the prediction and mitigation of NVP and psychrometric related events.

Jan 1, 1999

By Lynn B. Hales, Randy A. Yncbausti, Rick Smith

Object oriented programming has been developed to model the way we think about the world. It allows higher levels of abstraction, generalization and classification than many other programming techniques. Some tools of object oriented design and programming are encapsulation, classes, inheritance, modularity and reusability. Expert systems have been used for years to implement process control strategies in the minerals industry. Expert systems allow process control knowledge to be expressed in linguistic rules that are processed by an inference engine. Expert systems which employ object oriented design and programming provide new opportunities for real- time process control. The concepts of object oriented programming and an example object oriented expert system are discussed in this paper.

Jan 1, 1992

By Vaughn Astley, Hassan El-Shall, Ponisseril Somasundaran, Regis Stana, Patrick Zhang

In the past, when phosphate rock quality was good, few paid attention to any of the impurities or other qualities associated with phosphate rock. In general, they had little or no effect on the ability to make the phosphate products for the market. However, as phosphate rock quality declined, it was apparent to the rock consumers that the individual impurities had a significant impact on their processes. FIPR is presently funding an analysis of operating plant data to determine the range of the effects of rock impurities on production plant performance. The study will not be completed until 2002. IMC has agreed to share some of the information they had developed in the early 1990s.

Jan 1, 2002

By Mucella Ersoy, Nese Celebi

Management Information System (MIS), is a system using formalised procedures to provide management with appropriate information to make timely and effective decisions. Before developing MIS, first functions of the organisation should be defined and grouped into subsystems. After determining the information required and produced by each system and interaction between subsystems, the related data resources should be structured into a series of databases and files. In this study, the MIS developed for Soma Open Pit Mines, Turkey is described in this respect. First, analyses of the existing system including user requirements and scope of the system are given. Then the designed information system, its subsystems, interaction between subsystems and system structure are presented in detail.

Jan 1, 2002

By J. C. Harrison

When Exploraciones Eldorado, S.A. de C.V. finished their first phase of reverse circulation drilling at their La Trinidad property in Sinaloa, Mexico they began immediately with permitting and engineering activities. The first phase of drilling lasted four months and ended in April, 1994. The second phase of drilling ran from May through September of 1994. From May through December, 1994, Exploraciones Eldorado performed the permitting and engineering work for their La Trinidad heap leach mine. The mining permit was submitted to the regulatory agencies in February of 1995 and the first draft of the feasibility study finished one month later. The report outlines the permitting and engineering activities that took place during the second half of 1994.

Jan 1, 1996