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By M. W. Chanda

This paper presents the development of a rock-creep measuring apparatus using air as the initial pressure source. Servo-controlled machines can and have been used for time-dependent property tests. However, the long-term nature of some tests makes essential the complete independence of stress-maintaining equipment from main power sources or continuously running hydraulic pumps. The main objective of this paper is the development of a creep testing machine that is free from interference arising through power supply interruptions or mechanical maintenance normally associated with many compression testing machines. To achieve this, a compressed-air power source was used to drive a compression ram. A few trial results obtained and analyzed using the transient creep law are in reasonable agreement with the general creep law.

Jan 1, 1993

Bauxite mine rehabilitation is an important stage of today’s bauxite mining activities. To get an overall picture on those activities the International Aluminum Institute (IAI) has been carrying out Bauxite Mine Rehabilitation Surveys since 1991. The most recent survey from 2003 covers 70% of the world’s bauxite production and 23 corresponding companies from 12 countries. The survey activities show that nearly all operations refer to a sophisticated environmental management strategy. By setting up a review scheme based on the principles of the Global Reporting Initiative the compliance of this survey to aspects of Sustainable Development has been reviewed. The Clarification of a multitude of aspects based on the GRI guidelines helped to structure recommendations and relate them to the survey as such but also to the different stakeholders involved.

Jan 1, 2005

By J. Partyka

Fumes produced during blasting operations in underground mines are defined in this paper by an equivalent contaminant source. The primary goal is to establish a method which would allow all those parameters not measured directly to be determined reliably from field data. The parameters to be identified are the diffusion coefficient , and the position and size of an equivalent source. The diffusion-value is computed from the peak concentrations taken by two monitors located in the drift. The first monitor is placed close to where blasting pollutants join the main stream, while a second monitors is moved downstream a some distance from the first point. The position and size of the dust source and the total amount of dust produced during blasting are determined from the data recorded by only one monitor.

Jan 1, 1991

By F. M. Doyle, Jiang Tao, Xu Shi, Chen Jin, E. Peters

Tafel curve technique and leaching tests have been applied to study the kinetics of gold leaching with thiosulfate. Results show that cupric ions and ammonia play the part of catalysts in the leaching of gold with thiosulfate. The activation energy of gold dissolution is calculated as 27.99 KJ/mol in the absence of both cupric ions and ammonia. However, the energy is reduced to 15.54 KJ/mol in a solution of 0.01 mol/L Cu (NH3)2 4* and 0. 5moVL total ammonia. The reaction order of Cu (NH,) g is one in the range of 0.001~0.1mol/L. These results support the electrochemical-catalytic mechanism pro- posed by the authors and explains the behavior of cupric ion and ammonia (Jiang Tao, et al., 1993)

Jan 1, 1993

By Bob Clayton, David Readett

Jameson Cell technology has found applications in the cleaning of entrained material in copper Solvent Extraction - Electrowin plants. The materials involved are largely organic substances that have not been totally removed prior to treatment of the rich electrolyte in the tank house. This paper discusses the recovery of the entrained organics in the rich electrolyte streams at Phelps Dodge Morenci in Arizona. Mount Isa Mines in Queensland. Australia and the Olympic Dam Operations in South Australia. The paper details the design, performance, the feed and product characteristics, capacity and operation. In one operation the entrained material has been observed to include crud that has been formed in the SX train. The mechanism of recovery is also discussed.

Jan 1, 1993

By Leonard A. Eros

In many mining applications it is not practical to use gravity takeups. In these situations hydraulic takeups are often utilized. Performance specifications are often compromised by designs which have inherently high internal friction and inefficient hydraulic designs. This results in performance which does not match the requirements of the conveyor system. A computer model has been built to check unit efficiencies and field measurements have been taken which verify the results.

Jan 1, 1993

By N. Roqueñí, J. Loredo, F. Pendás

Impacts of mining on surface water and groundwater occur frequently not only in active mines but in abandoned mines, then the establishment of effective legal mechanisms for the regulation and control of mine waters is a necessary step in order to avoid pollution from mine waters and in consequence to contribute for a sustainable development of the mining industry. Currently there is a lack of a specific European legislation about mine waters and this absence of legislation occurs too at national level in many European countries. This absence of an European specific regulatory framework for mine water pollution questions the effectiveness and the applicability of the current legislation and this fact has led the EC to put forward proposals legislation to adequately deal with environmental and social consequences of mining, and among those proposals is a draft for a directive on waste from the extractive industry that includes provisions for mine water pollution.

Jan 1, 2005

By Kurt Burg, Allen Reicks

Tapered clamping devices have been used successfully over the years to transmit torque and bending loads from conveyor drives to conveyor belts. Proper design and application is important in the successful operation of these key components. This paper includes a historical review of component design and application and an overview of the important dynamics and limiting factors. Actual applications and simulation models are used to demonstrate the correct use of these devices.

Jan 1, 2002

By S. K. Kawatra, A. K. Bakshi

An on-line rheometer was developed to monitor the slurry rheology of a thickener underflow. The thickener processed a chalcopyrite flotation concentrate having a top particle size of 125 µm and a solids content of 30% to 60% (by weight). The slurry also contained residual flotation reagents, resulting in hydrophobic particles. Polymeric flocculants and lime were added to the thickener to flocculate the particles. Using the on-line rheometer, the slurry was found to exhibit pseudoplastic behavior with no yield value. It was also determined that factors other than the percent solids were responsible for changes in the slurry rheology.

Jan 1, 1999

By Shaoxian Song, Shouci Lu, Jingyon Gou, Pan Yiuwen

The calculated potential energies of interaction between hydrophobic particle of three minerals (rhodochrosite, quartz and talc) and air bubble show that the energy of hydrophobic interaction is the dominant factor for their attachment. An attachment rate equation, integrating particle -bubble collision and adhesion by introducing a "capture efficiency", has been put forward. It was found that the hydrophobic particle-bubble aggregates can not be disconnected in the bulk zone of flotation cell, whereas in the impeller zone the breakup may occur, particularly for the coarser particles captured by bubble. Finally, the flotation rate constant was estimated theoretically and verified by experiments.

Jan 1, 1995

By M. C. Roberts

The material composition of product is defined as the quantity of metal used per unit of product manufactured during a year. The material composition of product has shown steady and persistent declines over time for most metals and materials. This tendency demonstrates the continued improvements in manufacturing technology resulting from substitutions of other materials and increases in production efficiency. The purpose of this paper is to use the material composition of product to show the impact of advanced materials on the use of traditional metals.

Jan 1, 1992

By A. A. Sonntag, I. Szanto, D. A. Goodman

This paper presents the most recent developments in mixer-settler technology directed towards treating higher throughputs, increasing efficiencies and providing further improvement in SX technology with a new concept: the submerged launder. Industrial plants built in the last past few years and using these improvements are described.

Jan 1, 1993

By J. B. Gwiazda

In designing mine workings and adequate roof supports, it is indispensable to determine properties of the strata surrounding the workings. The proper selection of roof supports is based, before everything else, on a thorough knowledge of the roof rock strength, especially tensile strength. This parameter is a vital factor in the delamination of roof rocks and eventual cave-in. It is also important to know the properties of the floor on which the roof supports are set. While driving galleries, it is essential to know beforehand the strength of rocks that will be encountered in the near future during the work. The devices described will help to obtain this information.

Jan 1, 1987

By Colin C. Brooks

The Ok Tedi gold/copper deposit of almost 800 million tonnes was found in I968 because at that time technology had just developed sufficiently to enable exploration of such an area, world markets and prices for copper encouraged exploration for large deposits of low grade ore, Papua New Guinea law encouraged exploration by groups with men, money, management and expertise necessary for successful prosecution of such a search and such groups were already operating in the country.

Jan 1, 1990

By E. Jannoulakis

This paper introduces a practical methodology for analyzing vi¬bration records in view of improv¬ing blast designs and preempting anomalous vibrations. This technique, which is based on empirical data, uses a blasting-efficiency determinator (BED) as an indicator of vibration-energy transmission. The method was tested using data from a blasting event at an open-cast coal mine in the province of New Brunswick, Canada. The results derived from the BED values showed that geology and delay timing were probably the principal factors that induced high-intensity vibration propagation.

Jan 1, 2000

By V. Rajaram, D. P. O’Connor, L. Sakamoto

In 1988, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) imposed a no-blasting specification (blasting is restricted to the construction shaft and shaft bottom or boot) on the Deep Tunnel project. This was prompted by numerous complaints from residents in the vicinity of the project and controversies experienced on previous projects from blasting the rock overlying the tunnel. This paper will describe the methods used by two major contractors driving 20 km (12.5 miles) of tunnel, and drilling more than 36 shafts under this restrictive specification. The impacts are detailed on design, construction, schedule, cost and the environment.

Jan 1, 1993

By P. M. Godinho

The debut of the sustainable development concept in the political arena, and the publication of Our Common Future in 1987, represents the starting point of present concerns and efforts associated with the sustainability of the ecosphere and its ecological and human subsystems. The sustainable production and consumption of natural resources, in particular mineral resources, represents a central aspect of the problem. In this context, an important goal has been to develop sophisticated management systems, which consider sustainability principles, in organizations within the system of minerals and metals (SMM). The development of indicators is only part of this challenge. The extractive industries (EI) as an important stakeholder of the SMM (should) have similar priorities. If embraced, this challenge offers great opportunities, one of them being the potential for advancing the understanding of how these organizations learn and change. The identification of its main determinants offers, in theory, the possibility for their management and a faster achievement of the sustainability levels to which they (should) aspire.

Jan 1, 2007

By John F. Parmeter

On August 29, 1989, the Department of Labor, Mine Safety and Health Administration (MSHA), published a Federal Register concerning a new proposed rule on air quality, chemical substances and respiratory protection standards. As of this writing, their proposed rule has not become a standard. However, with little revision it could be expected to become a standard, and we in the mining industry will be expected to adhere to and enforce it.

Jan 1, 1991

By Don L. Jensen

With the successful implementation of supervisory control on the Bagdad concentrator grinding circuits, steps have been taken to expand supervisory control to the flotation circuits. This paper discusses the design and installation of the slurry delivery systems, analyzing instruments, level control devices, reagent pumps and supervisory software. Emphasis is placed on the design and installation of a reliable slurry transport system to feed the Courier 30 online analyzing instruments. Total system availability has been measured at plus 95%. Phase 1 acceptance testing of the supervisory software indicates a notable increase in copper recovery with no significant change in final copper grade.

Jan 1, 1999

By Peter K. Weissenborn, Robert J. Pugh

The contrasting behaviour of electrolytes in inhibiting coalescence of bubbles was explained by the positive and negative distribution of anions and cations at the gadwater interface. Further, the efficiency of electrolytes which do inhibit coalescence of gas bubbles can be linked to a counter ion hydration mechanism and the effect of electrolyte concentration on gas solubility. A correlation was found between the transition concentration of electrolyte needed to prevent the coalescence of bubbles and the reduction in gas solubility. Hence, the inhibition of bubble coalescence in electrolyte solutions appears to be linked with the utilization of water molecules in the hydration of cations and a consequent reduction of water available for gas solubility.

Jan 1, 1995