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By Andrew M. Garvie, William W. Plotnikoff, Eugenia Y. Kuo

Water infiltrating the surface of waste rock dumps transports pollutants into the environment. Lysimeters have been used to quantify the infiltration rate. To date their design has been guided by modeling under steady-state conditions. Recently a two-dimensional finite element code has been developed to model the response of lysimeters to time-dependent infiltration rates. It was used to investigate the response of lysimeters installed in a waste rock dump and subject to a monsoonal rainfall pattern. The results are presented and compared with field data.

Jan 1, 2000

By Robert A. Hains, William P. Balaz, K. Payne

Ceramics are usually used to line chutes, pipes, dust collectors, separators, cyclones or bins where abrasive or corrosive material is moving. Improvements in ceramic manufacturing methods and quality, use of other abrasion resistant materials in combination with Alumina ceramic, improved adhesives and installation methods allow the use of Alumina ceramic tile in applications with impact. This paper discusses the criteria to determine if ceramics can provide a cost effective alternative to other liners for abrasive material handling applications, design parameters for liner systems, system costs, and case histories. The goal will be to provide a practical guide for improving the performance of existing ceramic lined systems or determining if ceramics is a cost effective solution for your abrasive material handling applications.

Jan 1, 1996

The implementation of NAFTA in January 1994 was expected to have small but beneficial effects on the Mexican economy, mostly through increased investments. Mexico's mining industry was especially likely to benefit, as mineral investment funds would be diverted to the now safer Mexico and away from similarly endowed but more risky Latin American mineral economies. The results during the past two years have shown that it is government and macroeconomic factors that influence investment flows, rather than the fine tuning of trade flows through so called 'free-trade" agreements.

Jan 1, 1997

By J. F. Peterman, M. C. Roberts

The success of any industrial mineral project requires an accurate forecast of the demand fir the material as well as accurate projections of costs and prices. This paper develops a general method of predicting mineral requirements and applies it to the case of graphite. The basic method is to explain graphite consumption in each of its major uses by the output and manufacturing technology of the using industry. Once these underlying factors are determined, they can he projected to establish future requirements. This forecast is critical to the evaluation of a new source of supply, such as the graphite resources of Upper Michigan.

Jan 1, 1990

By A. B. Holland-Batt

In the 1960s and 1970s, incremental development rather than innovation was the norm for gravity separation. However, the last 15 years have seen a number of new developments in this area. The article reviews the traditional gravity-separation techniques and then examines the newer developments such as centrifugal separators. Emphasis is placed on novel devices or improvements that offer better control or improved performance.

Jan 1, 1998

By Fathi Habashi

Precipitation of a metal from an aqueous solution of its salts by another metal is known as cementation, because the precipitated metal is usually cemented on the added metal. This phenomena was once described by the alchemists as "transmutation," when they dipped a piece of iron in a solution of copper sulfate and the iron was coated with a layer of metallic copper. The process can be predicted in terms of electrode potentials. The metal with the more positive (oxidation) potential, as given in Table 13-1 of the electromotive series, will pass into solution and displace a metal with a less positive potential.

Jan 1, 1970

By Alvaro Souviron, W. W. Atkinson

The porphyry copper deposit at Los Pelambres is a resource exceeding 2 Gt (2.2 billion st) of 0.7% copper and 0.02% molybdenum. It includes a high-grade zone of +1% copper that is amenable to open-pit mining with a low stripping ratio. Metallurgical testing has indicated that the ore has exceptional characteristics, and that recoveries of 96% for copper and 93% for molybdenum can be obtained by conventional flotation methods. This paper summarizes the history of the prospect, the geology of the ore body and the surrounding area, and the procedures and results of exploration.

Jan 1, 1987

By K. Y. Haramy, B. T. Brady

A scale-invariant theory of the strength and deformability, of rock masses in static equilibrium and at incipient failure is proposed The theory provides a rationale, for designing structures in rock. This paper presents results of experiments conducted by the US Bureau of Mines and presents theoretical methods to determine and interpret the in situ strength of rock masses using the borehole shear tester.

Jan 1, 1996

By Hector M. Valenzuela, Juan H. Rojas

This paper presents a strategic plan for automation, plant integration and process management being implemented at the Chuquicamata mining and metallurgical complex of Codelco-Chile. This five-year plan considers different levels of process control and plant integration, which include instrumentation and direct control, process models and supervisory control, plant information integration, and real time process and plant wide management. The conceptual solution developed defines an architecture for the overall system and the projects to be implemented by each production unit, as part of the proposed solution for the division wide process control, plant integration and real time process management. An estimate of the cost benefit relation of the plan is also given.

Jan 1, 1998

By Barrie W. Sullivan

The New Celebration Gold Mine near Kalgoorlie in Western Australia was commissioned in late 1986 and the CIL treatment plant currently processes 1.7 million tonnes of gold ore annually. The 1988 geological resource was 13.2 million tonnes grading 2.37 g/t Au in several open pittable deposits with the bulk of gold mineralisation occurring as a stockwork in Archaean quartz feldspar porphyry intrusives along a major regional shear zone. Mine planning, scheduling and operating techniques have focused on minimising open pit dilution whilst maintaining production requirements. This paper describes the successful achievement of this aim in extremely variable ground conditions and orebody widths.

Jan 1, 1989

By D. E. Ranta, M. G. Schulz

Mining of Molybdenum at Questa, New Mexico has been accomplished by block cave methods since August, 1983. As caving progresses, a periodic geologic evaluation is made of the rock types present in finger raises on the Grizzly Level of the mine. The production maturity of the cave can be monitored by relating this data to geologic cross-sections through the orebody. The draw point mapping program is a simple and effective tool that is used in making draw control decisions at Questa.

Jan 1, 1992

By James Lonergan

This paper describes the application of the Graphics Assisted Under Ground Engineering (GAUGE) software to a 2-layered room and pillar hard rock mine. The graphics- assisted mine modeling and mine planning capabilities of GAUGE are demonstrated. The system uses polygons to model the room and pillar mine design and displays the model in plan view on the graphics screen,. The planning engineer interactively specifies areas to be mined in the medium or long term. The system calculates and accumulates tonnages and grades for the user-specified areas based on the layer being mined and the particular unit operation (drifting, widening or benching).

Jan 1, 1989

By Sushil Bhandari

A computer model is developed for the problem of dispersal of dust (suspended particulate matter) resulting from blasting operations in surface mines. Undulated surface (lower boundary) simulation was carried through sixth order polynomial by least square approximation. Segmentwise terrain simulation was linearly added to build ground feature extending either side of the blast location. Assuming the initial dust concentration in the vertical column to. be uniform and treating the finite vertical line sources as a series of point sources to height, H varying from zero to top of the dust mushroom, integration was done of the concentration effects from H = 0 toL tan[0] (L = horizontal distance of the blast location and [0] is the angle of the top of dust cloud from the point of observation). Using frame of reference moving with the mean wind, the ground level 'concentration (GLC) has been computed over the undulated terrain. Standard deviation (s) of concentration has been parameterized based on mixed layer similarity theory in convective boundary layer.

Jan 1, 2002

By W. Joseph Schlitt, Donald B. Swanson

The paper provides an overview of the role that contract mining plays in the minerals industry. Particular emphasis is on contract mining and its place in the development and operation of small to medium sized precious metal mines in the western United States. The paper begins with a discussion of the mining options available to owners. This is followed by a description of contract mining organizations and the services they provide. In addition to various mining activities per se, these can include other processing functions such as crushing and agglomeration, various types of heavy civil construction, other types of technical and administrative support, and even assistance with financing. Typical equipment spreads and unit costs are presented. Final 1 y, the advantages and disadvantages of contract mining are discussed. Liberal use is made of

Jan 1, 1987

By Marian Radetzki

The economic developments and industrial behavior patterns that led to a lasting excess capacity in the world non-ferrous metals industries from the aid-1970s are explored. Detailed attention is devoted to analyzing and defining crucial concepts like "capacity", "excess capacity", "capacity maintenance" and "investments". Empirical evidence of capacity utilization and capacity growth in the industries under study is provided. The coincidence of excess capacity and low prices on the one hand, and investments in capacity maintenance and capacity expansion, on the other, is seen as a consequence of substantial declines in the metal industries' investment and production costs during the period studied.

Jan 1, 1989

By Rudrajit Mitra, Wesley B. Johnson, Erik C. Westman

The ability to understand stress redistribution within a mine allows greater extraction efficiency with reduced safety concerns. Stress redistribution has been examined at the laboratory scale using ultrasonic tomography and numerical modeling using PFC3D. A data acquisition system was built to obtain tomograms as samples are loaded in uniaxial compression. Limestone samples were loaded to failure. Three-dimensional tomograms of the samples correlate to various stress distributions. The tomograms are compared to analytical and PFC3D results.

Jan 1, 2005

By Edward C. Dowling

Cleveland Cliffs and affiliated companies have established a commitment to the development and use of integrated process control. Substantial capital investments in process control, coupled with the dedication of human resources to effectively use the information, have generated meaningful business results. Improvements in productivity, operating costs and product quality have been realized. This paper presents an overall process control and information strategy, specific case studies, lessons learned and the current view of the next steps in the continued journey toward integrated process control and information management.

Jan 1, 2000

By Abdullah Arik

In deposits with highly skewed grade distributions, such as precious metals deposits, proper handling of the outlier high grade data is very crucial to the ore reserve estimation. Although some recent geostatistical techniques are available to handle the estimation problems with these outlier data, ordinary kriging or conventional methods are still widely used to estimate the ore reserves for such deposits. One reason for this is the fact that the alternative methods offered are either too complex or too exhaustive for the mine engineers and geologist who often do not have the expertise or the time to apply these methods. This paper presents a new 2-step kriging algorithm "Outlier Restricted Kriging" (ORK) which can be a simple and a practical tool to use where the ordinary kriging will fail to handle the outlier high grade data properly in block grade estimation. The paper details the methodology and discusses the results of its application to a gold deposit.

Jan 1, 1992

By Andrew F. McKown, Lewis L. Oriard

Advances in explosives engineering are moving forward in several different aspects. These include improvements and new development in explosives products, the application of these products to blasting technologies, and the study of the peripheral effects of the use of explosives, such as ground vibrations and airblast. Topics of special interest in the last several years include new explosives and detonators, cap timing, explosive casting, high-speed photography, perimeter and slope control, air decking and mathematical modeling of blasting processes.

Jan 1, 1988

By J. Brent Hiskey, Srini Raghavan

The physical chemistry of dissolution of silicate and complex oxide ores in aqueous lixiviants has been reviewed. Particular attention has been paid to the analysis of dissolution mechanisms and kinetic models and to the elucidation of the role of the porous nature of the materials on dissolution behavior. Importance of the physico-chemical characteristics of the leach residues on leaching efficiency has been discussed.

Jan 1, 1989