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By K. N. Han

The leaching behavior of palladium in ammoniacal solutions was investigated by using the rotating-disk technique in an autoclave. The study included the effects of rotation speed, temperature, oxygen pressure, composition of ammoniacal solutions and catalysts on the overall leaching rate. The dissolution of palladium in ammoniacal solutions was discussed in terms of the thermodynamics and a kinetic model. Even though the Eh-pH diagram suggests that palladium metal can dissolve in ammoniacal solutions at room temperature, it was found that the dissolution was very slow at temperatures below 100 °C but was significantly improved at higher temperatures. It was also found that the rotating speed of the palladium disk had no effect on the leaching rate. The apparent activation energy was found to he 69.7 kJ/mole. Based on the results obtained, it was concluded that the dissolution of palladium is controlled by chemical reaction.

Jan 1, 1999

By Roshan B. Bhappu

In situ mining and extraction is one of the Frontier Technologies that is destined to play an increasingly important role in the recovery of metals and minerals in the future. This premise is based on increasing costs of labor and energy, increasing awareness of environmental considerations and decreasing ore grades in the United States. Up to now, in situ mining has been successfully applied to a few favorable situations for the extraction of some evaporites, copper and uranium. However, because of its unique technical, environmental and economic advantages, this versa tile technology will find broader applications for the recovery of above commodities as well as for others which are currently extracted by hydrometallurgical means. This paper traces the development of in situ mining and extraction; stresses its dependence on interdisciplinary science and engineering; discusses its theoretical, practical and economic aspects; and finally presents potential applications of this Frontier Technology.

Jan 1, 1985

By M. Ruonala

The Larox Power PF Pressure Filter has been developed to meet the challenges of ever increasing output tonnages demanded by the minerals processing industry. This paper will highlight recent experiences at the Rudna Copper Concentrator in Poland, the Escondida Copper Concentrator in Chile and some large zinc concentrators in Australia. Detailed maintenance and operating cost information will be disclosed. Emphasis will be placed on economics on scale gained from higher machine throughputs.

Jan 1, 1998

By J. Engesser

This paper discusses the effect that water chemistry, and water treatment have on pre-fired pellet quality and bentonite-binding effectiveness. A discussion concerning the effect that water temperature, water chemistry, water treatment, and surface area have on disc filter productivity and filter cake moisture is also included. This report is a summary of the data that were presented in five previous research reports, which are listed as references in this paper.

Jan 1, 2003

By P. Ollivier

The ore-processing plant of the Soremib mine Pour a (Burkina Faso) has now been in uninterrupted operation for 3 years. Ores from the oxidized and non-oxidized zones of the deposit are processed together in one flotation unit. About 60% of the gold is free and is recovered in a gravity processing unit. The residual gold in the flotation concentrate is processed on the spot by cyanidation and carbon-in-pulp.

Jan 1, 1998

By James L. Parks

This paper describes improvements in SAG and AG mill liner designs and their cumulative effect on wear life and mill availability. Routine procedures used by many SAG and AG mill operators to improve liner life are reviewed. Guidelines are provided for estimating the time required to replace worn liners along with practical methods to reduce downtime for liner replacement. Finally, the effects of mill operating conditions on liner wear life and breakage are considered.

Jan 1, 1998

By B. C. Flintoff

In general, process control systems in solid-solid separation have not evolved to the same level as in flotation circuit control. Perhaps one of the more significant contributing factors in this regard is the lack of suitable on-line analytical instrumentation. In spite of the obstacles, some interesting work has been done. This paper presents a review of current industrial control strategies in ore sorting, dense media separation, gravity separation and electrical and magnetic separation.

Jan 1, 1986

? The U.S. depends on minerals for economic growth and development, and for national security and defense. ? Public lands are an important, long-term source of essential minerals. ? Access to public lands for mineral exploration and development has become more difficult as large tracts of land have been designated for other uses. ? Mineral-bearing areas on public lands are routinely withdrawn or restricted from development before comprehensive resource inventories and economic assessments have been made.

Jan 1, 2011

By Daniel Hodouin, Antoine Berton

Mineral processing plants are monitored and controlled using measurements that are usually processed by on-line material balance calculation techniques. However, gross errors, due to sensor biases or failures, may corrupt all the process variable estimates. On-line gross error detection methods are required to ensure efficient mass balance evaluation. In the proposed approach, material imbalances and raw measurement corrections are tested by statistical techniques designed to detect and isolate sensor problems.

Jan 1, 2000

By J. Muir

This report focuses on minimum ore block sizes that are economically feasible to mine with the vertical crater retreat (VCR) method. In 1985, Homestake Mining Co. began a program to bring several small block VCR stopes on line. This report examines these experimental stopes, including design parameters, ground control, drill patterns, secondary blasting, and mucking. Cost and scheduling comparisons are made with mechanized cut-and-fill and open cut- and-fill methods.

Jan 1, 1987

By Sylvain Duchesne, Claude Bazin, Robert Grant

Grinding simulators are now widely available to assist in the selection of circuit operating conditions or flowsheet designs that yield a given product size distribution. These simulators do not inform of the impact of the grinding product size distribution on subsequent flotation stages. This paper presents a method to predict the effect of fineness of grind on a flotation bank operation. Application of the method is illustrated with data from two Canadian concentrators.

Jan 1, 1995

By S. D. Thompson, J. C. Dzurino

This investigation mainly focused on designing a bunker system for a large underground coal mine. The primary purpose of this bunker system was to keep high- and low-sulfur coal segregated on the underground belt system. These bunkers were also required for protecting the mine faces from out by belt delays. Methodologies used in developing this plan are briefly discussed. The final design and the procedures formulated for implementing it are also presented.

Jan 1, 1987

By Karel SPIRKO

The one-dimensional mathematical model of unsteady-state heat conduction through semi-infinite homogeneous and isotropic airway walls with convective heat and moisture transfer between their wet or dry naked surfaces and mine air with time variable temperature and humidity has been developed on the basis of introduction of acceptable simplifications of description of heat and moisture transfer between rock mass and mine air. The analytical solutions for computation of the temperature distribution and surface temperature of the airway walls and floor and for calculation of water vapour pressure near the wet surfaces at given time are obtained by means of the model presented. The presented solutions are derived for general conditions and they could be easily adapted to the actual ones. Results of the model represent basis for balancing heat and moisture transfer between mine air and its surrounding in deep mines under time variable temperature and humidity of the air and enable us to solve complicated dynamic changes of mine air temperature and humidity in an airway system by relatively simple mathematical tools. INTRODUCTION The importance of unfavourable influences and the costs of condition arrangements increases with mine depth. Precision demands on the methods which predict the environmental condition changes and by which it is possible to optimize condition arragements are still increasing. Environmental conditions in deep mines are determined especially by flow velocity, barometric pressure, temperature, and humidity of mine air. Therefore new and more exact mathematical models of mine air flow through airway system and those of heat and moisture transfer between mine air and individual important sources of heat and moisture are developed. The paper presented deals with description and solution of problems of heat and moisture transfer between mine air and airway walls as the rock mass is one of the important heat and moisture sources in deep mines. There are several different approaches to the problem. In some models the moisture transfer between mine air and airway walls is not considered at all. In other models the moisture transfer is described only by certain empirical coefficients. Simultaneous heat and moisture transfer is described seldom. This paper tries to describe in a simple way simultaneous convective heat- and mass-transfer processes taking place on wet naked surface of airway walls by means of corresponding

Jan 1, 1993

By T. L. Heidrick

Late Cretaceous-early Tertiary Cordilleran porphyry Cu-Mo districts and their consanguineous Zn-Pb-Ag-Au-W vein and replacement deposits of the Rocky Mountain region comprise one of the largest, best studied, diverse, complex, puzzling, and richest compound metallogenic provinces on earth. A concise space-time definition of intermineral plate, regional and local structure-tectonic frameworks is crucial to deciphering their diachronous metallogeny and enhancing the explorationist's odds of future discovery.

Jan 1, 2013

By Fred W. De Vries

The history of mining-industry regulations on cyanide indicates a trend to set criteria based on generalized inferences related to its high toxicity. As toxic-inventory-motivated regulations are framed, material balances are expected to imply atmospheric releases of HCN as a major factor. A review of atmospheric data shows the probable triviality of any environmental impact of such releases, and suggests a very deliberate approach to any proposed regulations regarding these emissions.

Jan 1, 1996

By E. G. Joe

Introduction Uranium mining has been actively carried on in Canada for over twenty-five years mainly in Ontario at Elliot Lake in Bancroft, and in Northern Saskatchewan at the operations of Eldorado Nuclear Ltd. During this period, approximately one hundred million tons of mill tailings have been created and lie mainly on the surface close to the mining and milling installations. If all of the present reserves of uranium ores in Canada are mined, a further eight hundred million tons of mine tailings could be created in Ontario, Saskatchewan, the Northwest Territories, Labrador and British Columbia. The present control of effluents from existing tailings is managed by the operating mines under the regulations of both federal and provincial control agencies. It is the long-term effect of these tailings on the environment that has not been clearly defined or measured. Several years ago, the Canada Centre for Mineral and Energy Technology of the Department of Energy, Mines and Resources, embarked upon a program of research directed at the long-term effects of uranium mine tailings. Much of the research to date has been on tailings in the Elliot Lake, Ontario area where some tailings piles have existed for over twenty years. The program consists of two projects, one to address the problem of existing tailings and the other to examine alternatives in the management of current and future tailings. TAILINGS CHARACTERISTICS Uranium tailings are generally the result of sulphuric acid leaching in which the uranium and alkaline minerals such as carbonates and chlorites are leached out. If the ore contains sulphides, these minerals potentially present an additional hazard of acid generation over time and could increase the mobility of heavy metals and some radionuclides such as thorium-230. Except for the extracted uranium, most of the radionuclides from the ore remain in the tailings pile. Uranium ores in Canada span a wide variety of mineralization and associated gangue composition. Uranium minerals include pitchblende, uraninite, uranothorite, brannerite and the phosphate uranium minerals autunite and saleeite. Gangue minerals vary from acid consuming carbonates, and chlorites to acid producing sulphides and inert silicates. With such a wide variety in ore composition, the characteristics of the resultant tailings in Canada are in many cases site specific and the solutions to the long-term effects of these tailings may also be site specific.

Jan 1, 1980

By Kanaan Hanna, Mir Heydari, Dipack Sengupta, Gordon B. French

This article, first in two, discusses the safety, technology, and economic impact of eliminating safety fuse from metal and nonmetal mines. It is based on operation and manufacturer experience over the past five to 10 years. If safety fuse is eliminated, blasting accidents will decrease. There should be only limited technical impact. The economic impact will be minor for large operations, but will be significant enough for small operations that some will likely close rather than change. Most mines would probably change over, with the market absorbing the extra cost. Elimination of safety fuse would obviously have an impact on the two safety fuse manufacturers. One manufacturer produces an alternative system and would be unaffected. The other, however, will be affected if it does not change its production strategy. From the standpoint of employment and production, abolishing safety fuse will have a very minor effect on the mining industry as a whole. This article discusses the current use of initiation systems, incidence of accidents, and fuse consumption. Next month, part two describes the economic impact of eliminating safety fuse on the mining industry and manufacturers, and presents an economic analysis of the initiation systems. Introduction The objective of this study was to determine the safety, technology, and economics of eliminating safety fuse from metal and non-metal mines. There were five major tasks: • Studying initiation-related accidents from the Health and Safety Accident Center (HSAC) data file; • Visiting mines, collecting relevant data, and interviewing mine operators; • Establishing the trend in safety fuse consumption and type of users; • Corresponding with fuse manufacturers, domestic and foreign; and • Developing an idealized blasting cycle to evaluate the possible economic impact of safety fuse elimination on large and small operations. More than 450 explosives-related accident reports have been screened and analyzed by investigating HSAC files. These reports have been studied and classified according to the four initiation systems, size and type of mines, and time and frequency of accidents from 1973 through 1978. Twenty-four mining operations were visited to obtain supporting data for this study. Mine personnel were interviewed to determine attitudes about safety fuse and alternative detonating systems. This article decribes available data. It also attempts to provide information that can be used to answer such questions as: • Is the use of safety fuse (an antiquated detonation system) a major cause of mining accidents? • Are alternative systems available that could result in fewer in-juries to miners?

Jan 1, 1984

By Robin G. Adams

The market prices received by producers of internationally traded commodity metals have been, and continue to be remarkably volatile and unpredictable compared with most other traded goods and services. This volatility results in an erratic financial performance on the part of producing companies, disruptive and often inflationary cost changes for consumers, unreliable tax revenues and export earnings for host governments and severe social and economic pressures on local, sometimes remote, communities which are dependent on the activity in question. Generally speaking, price volatility appears to be associated with the inability of the metal producing side of the industry to regulate the volume of supply in a manner that is consistent with metal demand, which in turn reflects broad macroeconomic and industrial developments around the world. This statement does not purport to apply to all metals or to all instances of volatility of course. Price movements may occur as a result of pure speculation or even illegal manipulation of the commodity markets. Embargoes, boycotts and other politically induced supply changes may contribute. Threatened or actual strikes also cause artificial swings in sales volumes and prices. How- ever, most of these developments are of a short-term nature. Yet metals price cycles may last for several years, as demonstrated by the extended copper price trough from 1981 to 1986. This paper deals with price volatility which reflects long-term economic cycles and the adaptive processes that exist within the industry in response to such cycles. Special emphasis is placed on the role of forecasts and forecasters in these processes. It should be said at the outset that this reflects the personal experience of one forecaster working in private sector commercial consulting practices that are independent of producers, consumers and host governments. However, the experience does cover the entire period since 1973 and has involved working with a substantial majority of the major companies that supply high volume commodity metals. By way of background it should be stated that the post-1973 world economy has provided a challenging environment for forecasters. One cannot be precise about the forecasting record of either industry insiders or outside consultants, financial analysts and academic forecasters because comprehensive records have not been kept, or if they have the results are too embarrassing to be published. Institutions such as the World Bank have published forecasts of the prices of major commodities on a regular basis and these have, presumably, had some influence on financing decisions in the industry. This record along with our own experience and numerous discussions with metal producers, major consumers and host governments permits certain generalizations to be made. The most important of these is that during the early 1980s. from about 1980 through 1985/6, the forecasters system- atically and substantially over- estimated metal prices. While some fore- casters did correctly anticipate a recession in the early 1980s and some consequential decline in prices, the magnitude and duration of the decline was far greater than anyone foresaw. This systematic forecasting "failure" appears to have occurred independently of the forecasting methodology employed. Moreover, its extent cannot be explained by obvious factors such as incorrect macroeconomic assumptions. There appears to have been some kind of structural change in the world mining and metals industry over this period

Jan 1, 1989

By Robert L. Somerville

As more phosphate deposits are discovered and new mines are developed, the necessity of critically evaluating various rocks for phosphoric acid production recurs ever more frequently. This need is accentuated by the increasing number of, fertilizer plants being constructed on deep water at various locations to serve world markets and to take advantage of locally-available sulfur or sulfur-bearing ores. A major proportion of all phosphate rock mined is consumed by wet-process plants and this acid in turn is consumed, usually captively, in the manufacture of fertilizer. It is apparent, therefore, that the first question asked by the developer of a new deposit is - How will it work in a wet-process plant? and conversely, when developing a deep water, project, one of the early studies required is - Which of the available rocks shall we use? What is the correct price to pay? How do we compare one rock with another? The economic importance of even minor aspects of these questions

Jan 1, 1966

By A. L. Hornbaker

Management of mineral resources through land-use planning procedures is not a new concept, particularly at the local level of government. Colorado may well be one of the first states, however, to vigorously attempt to evaluate on both the state-wide and regional basis, mineral resource potential and to make certain that potential for mineral resources is included as one of the primary factors considered in the local land-use decision-making process. Less than a decade ago the only consideration given to mineral resource extraction, particularly aggregate resources, was whether or not they could be produced at the particular time they were needed. This attitude has now shifted to the other extreme, not only in Colorado, but other states as well, so that other interests, especially housing projects, mountain subdivisions, recreational and wilderness areas are gaining prime consideration in land-use decisions. Ideally, in a more acceptable median position, mineral resource potential would receive definite consideration at the local level.

Jan 1, 1977