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By Jose Luis Pineda Villarreal

New technologies emerge every day with practical applications for open pit mining. For every operation, managers need to understand the best way to increase efficiency in drilling, blasting, fragmentation and hauling routes.

Jan 1, 2018

By W. John Rankin

The finite and non-renewable nature of mineral resources poses unique challenges for sustainability: How can mineral and material needs of society be satisfied indefinitely? How can the benefits of exploitation of minerals best be captured for present and future generations? How can the environmental problems caused by large scale mining and processing best be ameliorated? These issues are rarely addressed, or if so only incidentally, in traditional courses in geology, mining, metallurgy and materials yet addressing them will increasingly be a major role for professionals in the minerals and materials industry and related sectors and agencies. This paper describes a framework for examining these and other sustainability issues related to meeting future material needs from non-renewable resources. The framework may be useful for educational purposes, either as the basis of a dedicated subject or by including the elements of it throughout a traditional course in relevant subjects.

Jan 1, 2014

By P. Maraboutis

Extractive industry (mining and quarrying operations), as other industrial activities, is subject to environment protection laws, regulation and standards such as the Environmental Impact Assessment directive, Natura 2000, Habitats & Birds directive, Water Framework directive etc The European Commission (EC) is aim to strengthen the EU environmental legislation to improve the (environmental and human) safety of mining activities. The mineral processing and the management of the mining waste will be covered by the new amendment of the Seveso II Directive, by a Best Available Techniques reference document (BREF) describing the Best Available Techniques of mining waste management and a new directive on the mining waste management. At the same time initiatives as the environmental liability, the energy taxation for environmental reasons and the natural resources management policy, which will have a positive impact on the protection of the environment, will affect the extractive industry operation procedures.

Jan 1, 2002

By T. P. Meloy

Economic constraints require that the optimum mineral processing circuit be chosen for a given ore and then the circuit be optimized. Meloy (1983) developed a general methodology for finding the best circuit for a given ore. This analysis, however, did not specify a way to optimize the best circuit once it has been found. To optimize a given circuit, it is necessary to find the optimum set points for each unit operation in the circuit. Developed in this paper is a simple, general equation which, when applied, defines the optimum separation set point for the maximum mineral grade. This general equation, Equation (4), applies not only to simple ores, but also to complex ores containing variable and locked particles. Currently, the optimum set point can be calculated only for heavy media and cyclone circuits, because they are the only unit operations for which the necessary data has been measured.

Jan 1, 1984

By K. V. S. Sastry, V. P. Mehrotra

A laboratory investigation was carried out to study the influence of asphalt, bentonite, and corn starch binders on the pelletization kinetics of coal fines and on the quality of the resulting pellets. Pellet quality was evaluated in term of the compression strength, impact resistance (drop test), abrasion resistance, and resistance to severe weather conditions. The amount of binder addition did not significantly influence the pellet growth kinetics. However, the pellet quality varied markedly depending upon the type and the amount of binder wed. Experimental results are explained on the basis of the mechanism of interaction between the coal particles and the binders. Of the three binders tested, corn starch proved to be the best in all respects but for the resistance to water penetration. Finally, a combination of corn starch (imparting strength) and asphalt emulsion (imparting resistance to water penetration) was found to yield the best quality coal pellets.

Jan 1, 1983

By David R. Maneval, Sylvester Lemezis

All acid mine drain waters, regardless of source, share certain characteristics; but they do differ in exact chemical composition, degree of acidity, and total solids content. Any serious program to treat such waters must recognize these differences and apply to each specific case the technique which offers the best promise of each specific case the technique which offers the best promise of technical and economic success. The Pennsylvania Dept. of Mines and Mineral Industries has originated and funded studies of many different treatment means. Neutralization with lime is now being used on 200 different polluted streams in Pennsylvania, and multistage flash evaporation has been selected for a particularly large and troublesome outfall near Wilkes-Barre, Pa. A 5 x 106 gpd plant for this latter site is now being designed by Westinghouse Electric Corp. which developed a concentration process based on multistage flash evaporation as part of the State's research program.

Jan 1, 1973

By Vikram P. Mehrotra

A laboratory investigation was carried out to study the influence of asphalt, bentonite and corn starch binders on the pelletization kinetics of coal fines and on the quality of the resulting pellets. Pellet quality was evaluated in terns of the compression strength, impact resistance (drop test), abrasion resistance and resistance to severe weather conditions. The amount of binder addition did not significantly influence the pellet growth kinetics. However, the pellet quality varied markedly depending upon the type and the amount of binder used. Experimental results are explained on the basis of the mechanism of interaction between the coal particles and the binders. Of the three binders tested, corn starch proved to be the best in all respects but for the resistance to water penetration. Finally, a combination of corn starch (imparting strength) and asphalt emulsion (imparting resistance to water penetration) was found to yield the best quality coal pellets.

Jan 1, 1981

U.S. Borax’s mine in California’s Mojave Desert is the source of nearly half the world’s supply of refined borates. These minerals are used in hundreds of products, including essential plant nutrients that increase crop yield and quality, and safe building products that protect homes from insects and the elements. Borax’s workforce is also safe. In fact, it is among the safest in the nation. In 2003, the company was recognized by the U.S. Mine, Safety and Health Administration (MSHA) for achieving the best safety record among large U.S. mining operations. It was also recognized by its parent company, Rio Tinto, for achieving the best record among its nearly 80 worldwide mining operations. Borax’s safety performance is five times better than the national average. And its workforce recently achieved more than two million hours without a lost-time injury.

Jan 1, 2004

The increased focus on best practice environmental management has led to mining and mineral processing companies developing a variety of procedures to ensure that the environmental impacts of their operations are minimised, and that company managements are fully aware of these impacts and the policies and procedures established to ensure this process. Parallel to this, international standards for the development and implementation of environmental management systems are being promoted as necessary for companies to demonstrate their due diligence. Good environmental management systems should be built upon the systems already established within companies, and should ensure that the process of continual improvement is integral to their operation. An outline of the basic components of environmental management systems is provided, along with examples of the way various mining companies have implemented such systems. The benefits of best practice environmental management to mining companies are also considered.

Jan 1, 1995

By Deborah McCombe

-Canadian Regulators -Qualified Person -Professional Association -Resources & Reserves -Foreign Codes -Disclosure of Historical Resources -Issues in Application of Resources & Reserves -Industry Best Practices developed by CIM -Technical Report and Reserves and Resources -Summary

Jan 1, 2003

By William E. Sopper

Heat-dried municipal sludge was applied to a barren burned anthracite refuse bank in 1974. Sludge was applied at rates of 0, 40, 75, and 150 dry metric tons per hectare" Ten species of trees were planted and five species of grasses and legumes were seeded for evaluation. One plot was also irrigated with sewage effluent. The 150 t/ha sludge application rate produced the best overall herbaceous vegetation growth response. The 40 and 75 t/ha sludge application rates produced the best tree seedling growth response. Foliar analyses for trace metals indicated no phytotoxity problems. Analyses of leachate water at the three-foot soil depth indicated that the sludge applications did not impair water quality. Results of the study indicate that treated municipal sludge can be used to revegetate land disturbed by mining activities without adverse effects on the vegetation or water quality.

Jan 1, 1978

By AIME AIME

CHARACTERIZING the annual meeting as the biggest and best one yet has happened so repeatedly that some may suspect it has become a conventional phrase, like "good morning," and yet, what else can be said when not only one but all the many who express an, opinion use exactly those words, while the first of the two adjectives refers to a physical fact that is established by count. Perhaps there were hose who thought it not the best, but if so they were too tactful to say it out loud. So without further ado . let us admit that the one hundred and thirty-ninth general meeting of the A. I. M. E. held; as our By-laws provide, in New York during the third week of February, was the biggest and best of them all. Perhaps it is because we appreciate friendliness more as we grow older, but somehow the friendly atmosphere seems to rise slowly in temperature with the passing of the years. The actual atmosphere on the opening morning was quite the contrary, Feb. 17 being the coldest clay, so far, of this winter, and the suburbanites claimed that their thermometers had registered 5" below zero when they got up, though the official records of the weather man did not go that low. From that time the temperature steadily rose until Thursday afternoon, when the official record of 66" constituted a record high for Feb. 20 at New York. The weather man explained it by learned discussion of highs and lows, but we suspect the A.I. M. E. members must have had something to do with it.

Jan 1, 1930

By C. R. Hayward, H. O. Hofman

I. INTRODUCTION. THE aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation: The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class may work as a whole, each member contributing his share to the solution of a problem, or the students may carry on investigations independently; the former exemplifies class-research; the latter, individual research. It is with a branch of the former, with special reference to ore-treatment that the present paper intends to deal. In smelting an ore by a well-established process, the result is shown by analyzing the products to see whether their compositions correspond to those calculated in making up the charge; by taking account of stock to show the distribution of metal in the different products made and the losses from dust and volatilization, by casting a thermal balance to find the ,distribution and losses of heat; and by making a cost-sheet to ascertain, as far as possible, the necessary outlay of money. In, lixiviation and amalgamation, the mode of operating has to be varied to adapt a process to the individual ore. Here a number of tests become necessary. Each will consist of a series of experiments with one variable, in order to find the conditions under which the variable gives the best result; a. summary of several tests will give the best method of operating.. Working a number of charges with the best method will furnish the data desired for ascertaining the recovery of metal,

Jun 1, 1909

By Michel Brissette

"To recover more valuable ore and considering the complexity of minerals, the needs to grind finer is increasing. To reach the desired fine grinding targets, using the existing grinding media size, the energy consumption is increasing exponentially. As already proved at this conference, small grinding media represents the best potential to improve grinding efficiency. How do the small grinding media perform in industrial grinding mills?The use of small grinding media in regrind mills proved that finer grinding can be achieved at lower energy consumption. In ball mills, smaller grinding media versus 25 mm media generate a power saving from 10% to 44%. In vertical stirred mills, the power saving increases from 20% to 60%. More potential savings have been identified.For the same operating conditions, how a vertical stirred mill is performing compared to ball milling? In regrind application, a vertical stirred mill with small media (5-12 mm Millpebs) will require at least 62% less energy than a ball mill charged with 25 mm grinding media.INTRODUCTIONIn some mining applications, fine grinding is needed to liberate further the valuable ore. The purpose of regrind mills is to achieve the last stage of grinding before final flotation stage: the cleaners. In part because of high prices of small grinding media as well as availability, the most widely used size of grinding media is 25 mm.When calculating the recommended ball top size from Bond’s formula (Bond, 1961), the size for regrind applications is much lower than 25 mm. Today, the barrier for small grinding media is broken. They are best suited in regrind application. The size of grinding media is one of the most important variables affecting the mill efficiency (McIvor, R., 1997; Nesset, J.E., Radziszewski, P., Hardie, C. & Leroux, D.P., 2006).Conventional ball milling was discarded for fine grinding because of its very poor energy efficiency (Zheng, J., Harris, C.C. & Somasundaran, P., 1994; Yan, D.S., Freeman, M. & Dunne, R., 1995). Therefore, new technologies as stirred mills were developed to grind finer more effectively. Three fundamental questions should be asked. What is the best fine grinding technology? What should be the best media size to use? Is it possible to grind finer by using less energy with the existing regrind equipment?"

Jan 1, 2009

By R West

The Olympic Dam smelter facility processes copper concentrate feed using direct-to-blister smelting technology to support the current site production rate of 225 000 t/a copper. The metallurgical control of the Olympic Dam smelter is largely managed from a single central control room. Control room operation and management is therefore a key function in ensuring safe and reliable operation of the smelter, including identifying and initiating control of abnormal events. As part of a consolidated smelter reliability improvement program, a team consisting of process and control system engineers was formed. The teamÆs charter was to address and resolve the alarm flooding issues being faced by the control room technicians and the lack of an up-to-date base of supporting functional documentation. The project was successfully resourced with WorleyParsons metallurgists, Citect PLC technicians and the on-site technical team. Implementation was conducted over a 12 month period with the goal of achieving best practice alarm levels. The goal was achieved through a systematic process of alarm design review that analysed every configured alarm versus best practice design standards. Innovative concepts such as group-based alarms, first-up interlock displays, graphic only alarming, alarm help and alarm shelving were developed and implemented in conjunction with improved alarm masking. Total configured alarms were reduced from 20 000 to 5000 while the alarm rates were reduced from in excess of 200 alarms per hour per controlling technician to best practice levels of less than 12 alarms per hour per controlling technician. Completion of this program has provided a firm foundation for implementing further control optimisation and was a key activity in supporting sustained smelter reliability levels.

Jan 1, 2005

By C. R. Hayward, H. O. Hofman

The aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation. The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class may work as a whole, each member contributing his share to the solution of a problem, or the students may carry on investigations independently; the former exemplifies class-research; the latter, individual research. It is with a branch of the former, with special reference to ore-treatment, that the present paper deals. In smelting an ore by a well-established process, the result is shown by analyzing the products to see whether their compositions correspond to those calculated in making up the charge; by taking account of stock to show the distribution of metal in the different products made and the losses from dust and volatilization; by casting a thermal balance to find the distribution and losses of heat; and by making a cost-sheet to ascertain, as far as possible, the necessary outlay of money. In lixiviation and amalgamation, the mode of operating has to be varied to adapt a process to the individual ore. Here a number of tests become necessary. Each will consist of a series of experiments with one variable, in order to find the conditions under which the variable gives the best result; a summary of several tests will give the best method of operating. Working a number of charges with the best method will furnish the data desired for ascertaining the recovery of metal,

Jan 1, 1910

Longwall mining has historically been considered an application for only deep reserves. This has changed in the recent past as longwall has become competitive with surface mining. Many resources marked for stripping now he in the domain of longwall. Today, the best longwall mines compete with strip mines operating in even the lowest stripping ratios. Longwall mining has become more widely applicable than it ever has been in the past and it is now generally considered the method of choice in situations where high levels of coal production are required. But the best way to use longwall mining has become less certain with the opportunities that highwall access provides. Wall-to-wall mining is the use of retreating longwall developed from and retreating toward a highwall. As a surface mine reaches its ultimate highwall, the opportunity for longwall punch mining or wall-to-wall mining is obvious. There are several clear operating advantages to operating a longwall in this way and where highwalls are available, the best economic decision will generally favor planning a direct approach. Yet wall-to-wall is not applicable in every situation even when highwalls are available. Moreover, the advantages of wall-to-wall mining do not always justify the cost of trenching or box cuts to access coal . However, many tactical advantages of operating from the highwall can be realized with the use of specially equipped blind drilled or raised bored shafts. This paper discusses novel techniques for a shaft assisted mining system which permits the addition of conveyor structure and mine systems from the surface to the face for advance and retreat mining with longwall, shortwall or room and pillar panels.

Jan 1, 1998

By Robert C. Johnson

Single crystal whiskers of ZrO2 and TiO2 were grown by solution and crystallization of these oxides in molten baths. Mixtures of Na2B407 and LiC1 were the most suitable growth media for zirconia. Sodium borate alone and Na2CO3 plus SiO2 were best suited for titania. The solubilities of zirconia and titania in molten sodium borate were determined, Whether zirconia whiskers were dendritic or nondendritic depended on the temperature used. The best single crystal whiskers were grown below 1,100° C. Titania whiskers always grew as single crystals. The tensile strengths of zirconia and titania whiskers were about 15,000 psi and 50,000 psi, respectively. Modulus of rupture was about 49,000 psi for zirconia whiskers and 75,000 psi for titania whiskers. Chemical analyses showed the zirconia and titania whiskers to be pure. The zirconia and titania whiskers were shown by X-ray analysis to be, respectively, baddeleyite and rutile.

Jan 1, 1965

By J. Mizera, J. Zdunek, K. J. Kurzydlowski, A. Dobkowska

This work concerns comparison of corrosion resistance of the aircraft aluminum alloy composed of Al - 2.3%Li - 0.1% Zr. The alloy was hot rolled (HR) from 13 mm to a thickness of 4 mm (e = 2.4) and 1 mm (e = 5.2). Corrosion resistance was investigated by Potentiodynamic Polarization Test. The investigation relied on exposure samples in two different corroding medium: 0.5 M NaCl solution and 0.01 M Na2SO4 solution with added 0.01% of Cl- at room temperature. Furthermore, the microstructure was analyzed using the optical microscope with polarized beam. The hardness was measured on lengthwise profile. It was stated that alloy after the largest deformation (equivalent total strain e = 5.2) is characterized by the best mechanical properties and the best corrosion resistance. The alloys in initial state and after deformation to 4 mm (e = 2.4) are characterized by worse corrosion resistance. It is associated with microstructure and density of dislocation in analyzing material.

Jan 1, 2015

By AIME AIME

CERTAINLY in point of attendance, and doubtless in several other ways as well, the 147th meeting of the A.I.M.E. was the best ever held. In times of depression, mining engineers and metallurgists have plenty of time to come to the Annual Meeting but money is scarce; at the height of industrial activity they have plenty of money but no time. "The current period of transition seemed to provide ideal conditions for' both the preparation of papers and attendance at their presentation. The weather made even the Californians present envious though the weather man gets no credit, for rain and snow was what he willed. Among the elevator men, the miners have the reputation of being the toughest crowd to handle, though the best natured, withal, of all the engineering groups that meet in the Engineering Societies Building. This year Your inquiring reporter was told, "it was the damnedest meeting I ever saw; they

Jan 1, 1937