Search Documents

By L. Xinguang

Shandong MinMetals Corporation, a state-owned import and export organization located in the city of Qingdao, Shandong Province, China, was opened in 1954, with the mission of marketing metal products and industrial raw material in oversea areas for hard currency to support the modernization project of the country as well as the province. The management officers are appointed by the provincial government, and report to the Foreign Trade Department of Shandong Province. Meanwhile, the company also receives guidance from MinMetals head office in Beijing, the capital city of China. The head office does not own and control any provincial MinMetals organizations, but merely coordinate business among provinces.

Jan 1, 1990

By H. Venkatesh, Balachander R.

This article discusses the method that was adopted for controlling damage to rock mass while excavating an underground powerhouse cavern at Tala Hydroelectric Project. It discusses in detail the near field vibration studies carried out and the safe vibration levels established for that rock mass condition.

Jan 1, 2006

By Virgil A. Marple

The objective of this contract was to investigate time-integrated and real-time methods for determining the diesel exhaust particulate concentration in underground mines, in particular, coal mines. The microorifice uniform deposit impactor (MOUDI) is recommended for obtaining the time-integrated measurement of the size distribution. The mass concentration of diesel exhaust particles can be obtained from the particle size distribution of mine aerosols. On a mass basis, diesel exhaust particles are primarily in the submicrometer size range while coal dust particles are larger. Size distribution measurements made in the laboratory and in three underground coal mines exhibited two distinct modes with the diesel exhaust particles in the smaller particle mode and the coal particles in the larger particle mode. The point of separation between the two modes occurred in the 0.7 to 1.0 pm size range. The separation was found to be independent of mass fraction of the diesel exhaust particles, particle concentration and sampling site. Methods recommended for further consideration as real-time monitors of diesel exhaust aerosols in mines are photometers and filter pressure drop techniques. A preclassifier would be required in both cases to separate the larger dust particles from the sample. The Metrex Mineral/Diesel Photometer should also be investigated further once the electronics problems are eliminated.

Jan 1, 1986

By Peter Fullagar, Adel Vatandoost, Steve Walters, Toni Kojovic

"Traditional comminution tests are a vital component in every mine plant design. Comminution behavior governs both the cost of equipment and its operating efficiency. Most comminution tests are conducted off site on a limited number of samples, owing to the high costs and long lead times involved. Therefore a strong incentive exists to find alternative means for efficiently characterizing comminution behavior for a truly representative suite of samples. The potential for inferring comminution behavior from drill core is investigated in this paper. Our approach involves development of small scale comminution tests on the one hand, and measurement of a wide range of core attributes on the other. Our focus is the relationship between petrophysical properties and comminution behavior.Petrophysical properties of archival diamond drill core from the Ernest Henry Mine (Queensland, Australia) have been measured using a Geotek multi-sensor petrophysical core logger. We have investigated the relationship between the petrophysical properties and the corresponding small scale A*b and estimated Bond mill work index test results for 2m composites of the core. Core samples were petrophysically classified by means of cluster analysis. Comminution behaviour was then modeled for each cluster via multiple regression. The results suggest that prediction of the comminution behavior on the basis of petrophysics is viable at Ernest Henry.INTRODUCTIONMineral processing is the most important downstream operation for mining engineers and metallurgists since most mined materials are subjected to some type of comminution or beneficiation operation (SME, 1992). Comminution or size reduction is typically the first stage of processing. Size reduction steps (crushing and grinding) in any plant consume large amounts of energy, normally more than 50% of total energy (Weiss, 1985). Therefore, it is desirable to obtain laboratory results to design the size reduction equipment appropriately. One of the main factors that control the selection of hard-rock crushing equipment and the design of a crushing circuit is the mechanical character of the ore(s). Work index, density, abrasivity, compressive strength and clay content are essential parameters for ore characterisation (SME, 1992)."

Jan 1, 2009

By J. B. Elizondo

This paper, which describes mining methods and practices at the Piokee mining unit and the Piokee expertmental mining project of The Eagle-Picher Co. in northeast Oklahoma, is one of a series being prepared by the Federal Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Piokee unit, comprising the Piokee, Rowe, Lucky Syndicate, and parts of the Netta White and Otis White leases, is in the SW1/4, W1/2NW1/4SE1/4, and W1/2SW1/4SE1/4 sec. 17, T. 29 N., R. 23 E., Ottawa County, Okla. (figs. 1 and 2), The 200-acre tract is adjacent to the town of Picher and near the heart of the Picher field of the Tri-State zinc-lead mining district.

Jan 1, 1959

By R. S. Dean

"It has long been recognized that the properties of polycrystalline substances are not the same as those of single crystals. These differences are especially marked in metels and metallic minerals, and are of greatest practical importance in metal working and ore treatment. The property changes encountered in passing from a metal single crystal to a poly-crystalline aggregate are the same as are produced by cold-working a metal or by the precipitation of a disperse phase. Hence, we may logically assume that the property changes are all due directly or indirectly to the formation of interfacial area or internal surface. Our problem, then, is to ascertain the physicochemical state of the metal atoms at such internal surface and show how this physicochemical condition accounts for the pronounced changes of mechanical, magnetic, and electrical properties that accompany increased internal surface.GENERAL CONCEPT OF INTERNAL SURFACEIn 1678, Huyghens attempted to explain the double refraction of calcite by postulating that crystals were built from a regular arrangement of ellipsoidal particles. Over 100 years later, Abbé Hauy concluded from his studies of cleavage that crystals might be built from small units, but the units were of the same shape as the entire crystal. This idea, which was prevalent in mineralogical thought before the advent of X-ray spectrometry, was discarded when the great success of Bragg made it appear that the chemical atoms were in reality the elements of structure. In the further development of X-ray technique, however, C. G. Darwin, in England, and P. P. Ewald, in Germany, found it necessary to postulate crystal units con¬taining many atoms. The latter gave the name of mosaic crystals to those so constituted. The individual units are supposed to Possess the ideal atomic arrangements revealed by the X-ray but are not oriented with respect to one another."

May 1, 1938

By S. G. Ozkan

Boron minerals of economic importance are primarily colemanite, tincal, and ulexite. Turkey and the United States are the leading producers of boron minerals and compounds. Other production includes datolite in Russia and synthetic colemanite in Chile. This paper will discuss various types of chemical and physical treatments of boron ores to produce the marketable minerals and compounds that are consumed in commercial products.

Jan 1, 1995

By Linneas W. Laage

The purpose of this report is to document the fire experiments conducted at the Waldo Mine, NM during March 1990. The U.S. Bureau of Mines is concerned with improving and validating the predictive capability of the mine ventilation and fire simulator, MFJRE. To accomplish this, fire experiments were conducted at the Waldo Mine and temperature profiles were developed as functions of time and distance from the fire. These tests then provided data for verifying the heat transfer model in the MFIRE mine ventilation and fire simulator. An initial analysis of this data indicates that it will serve this purpose well. This report summarizes the data obtained during six fire tests at the Waldo Mine.

Jan 1, 1994

An extensive series of tests was carried out on a ball mill-rake classifier circuit in the New Broken Hill Consolidated Ltd. concentrator. The data were used to develop a mathematical model of the operation of a rake classifier and this model has been used in the simulation of the performance of a ball mill-rake classifier circuit on a digital computer. As a result of this simulation it has been possible to develop a technique for the optimization and control of a circuit which includes these units.

Jan 1, 1967

By C. V. Deutsch, O. Babak, J. G. Manchuk

High levels of geological heterogeneity occurring over relatively short distances pose a challenge to the unconventional open-pit techniques used in oil sands mining. There is strong motivation to mine selectively and minimize dilution and loss; however, the large equipment and high mining rate used to meet production targets tend to reduce selectivity. A numerical model is developed to account for geological complexity, mining equipment, regulatory criteria, and other operational parameters. This framework is used for more accurate forecasts, optimization of equipment, and other operational decisions. An example demonstrates the approach in light of Alberta Energy Regulator criteria.

Jan 1, 2014

By D. Tsweleng

In the Evraz Highveld production process, iron ore is prereduced in rotary kilns prior to charging into submerged arc furnaces (SAFs). Owing to the highly aggressive slags that are formed within the combustion zones of these kilns, chrome-oxide-containing lowcement castables have been used for some years in the kiln lining. Due to concerns around the potentially harmful effects should Cr(V1) be present in the spent linings, Highveld and its suppliers of kiln castables devoted time to developing alternative chrome-free lining materials. Such materials needed to be cost-effective and ensure good performance and improved kiln availability. This paper discusses all the parameters surrounding this development. Keywords Low-cement castable, chrome-oxide free, chrome (VI), titaniferous magnetite ore, rotary kiln, submerged arc furnace, open slag bath furnace, Evraz Highveld Steel & Vanadium Limited.

Aug 1, 2013

By AIME AIME

IN ORDER to carry on its work most effectively, the Committee on Industrial Organization (now known as the Committee on Industrial Relations) consists, of .a number of sub-committees, each composed of a chairman and members who are especially fitted to carry out the work designated by its title. With only one or two exceptions, all of these committees made reports at the New York meeting of the Institute, in February of this year, abstracts of which follow.

Jan 1, 1920

By Paul S. Goodman

Volume I This report presents the first national survey of miners' attitudes and opinions about their-work. The goal is to present attitudinal data that bears on coal production. Interviews were conducted in 26 mines with 2,000 miners. High levels of cooperation were exhibited by management, union and the employees. Data are presented about miners' attitudes about general aspects of their work such as pay, supervision, their jobs, etc. Another section of this report reviews opinions about specific aspects of work performance. Recommendations are presented.

Jan 1, 1985

By I. Liebman

The Bureau of Mines conducted research to develop triggered barrier systems for protection against gas explosions that can occur in underground coal mines during the use of continuous miners. Several extinguishing agents were tested in barriers at a simulated mine face. Water, powered by pressurized nitrogen, was found to be efficient in stopping fully developed gas explosions, but it had little effect against the explosion during its incipient stage. Hybrid combinations of currently known extinguishants, however, were successful against incipient explosions. Three hybrids that were developed and tested consisted of Halon 1301, combined with either an aqueous foam solution, water, or a dry chemical powder. The three hybrids were found to be more efficient than any constituent alone. Results of the tests point to a synergism between the hybrid components, and indicate that the Halon aids in dispersing its constituent and also converts the aqueous foam solution into a stable fine foam and the water into fine drops.

Jan 1, 1978

By E. L. Thyse

Keywords: Pyrometallurgy, converter, nickel, matte, distribution Metallic elements occupy a wide range in granulated nickel converter matte phases. The distribution of these metallic elements, particularly during crystallization path events, appears to be poorly understood. The present study serves to investigate the distribution of Fe, Co, Ni, Cu, and Pb between nickel-sulphide, copper-sulphide, and alloy phases. A novel combination of thermo-chemical modelling, electron microscopy, and electron probe microanalysis was applied to understand crystallization path events and the associated metallic element distribution. This study has demonstrated that major Ni incorporated during copper-sulphide crystallization would serve to mobilize minor Co towards distribution in copper-sulphide phases. In addition, solid solution substitution of Cu by Ni is manifested by compositional zoning of copper-sulphide phases. The role played by Ni during alloy crystallization suggests that minor Co was also mobilized, along with an increase in principal Ni. Fe, by contrast, seems to be incompatible with principal Ni. In addition, solid solution substitution of Ni with PGEs and Cu is manifested by compositional zoning of NiCu-alloy phases.

Jan 1, 2011

Production targets are the basis for almost every decision made by operations personnel in the daily operation of a concentrator. It is the production targets that determine how the plant is operated and therefore determine its efficiency. However, to achieve maximum plant efficiency production targets must be relevant to the process and achievable.In RoseberyÆs case, for many years, production targets were taken from budget data which, with the exception of mill feed tonnes and grades were carried forward from the previous budget. The zinc concentrate grade target was fixed at 57 per cent Zn, a long-term average; it was the accepted æstandardÆ for Rosebery. Historical data showed this target was never consistently achieved and plant efficiency was highly variable.Investigations into the possible causes for the variable performance ruled out plant and mechanical issues. Despite the Rosebery concentratorÆs age the plant and equipment are more than serviceable and reliable. The mineralogy of the ore and specifically the iron content of the sphalerite was found to be the most significant determinant of zinc concentrate grade. It was found with increasing frequency that the zinc grade of the sphalerite in the ore was below the zinc concentrate grade target. Consequently on these occasions attempts to meet the required concentrate target destabilised the process resulting in plant inefficiencies.Using the correlation between iron and zinc, data modelling was able to accurately predict the maximum zinc concentrate grade achievable for any ore type. By using on stream analysis instrumentation the operations personnel are now provided with constantly updated concentrate grade targets. By knowing the mineralogical limits of the ore at the time it is being treated process stability is maintained allowing plant efficiency to be optimised. This has resulted in a step change in plant performance and a significant increase in revenue.CITATION:Harris, G R, 2012. Developing and implementing ore-specific targets for the Rosebery Concentrator, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 321-324 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By M. M. Ali, C. Musingwini, R. A. Phillips

The long-term open-pit mine production scheduling problem (OPMPSP) is typically solved in two broad stages. The first stage entails optimisation of the ultimate pit limit, which delimits the economical final pit and maximises the undiscounted value of the deposit. The second stage entails optimisation of the long-term open-pit mine production scheduling, which maximises the discounted value of the deposit. The long-term OPMPSP is a type of an NP-hard problem, such as the travelling salesman problem (TSP), because it is intrinsically complex to solve since it incorporates both hard and soft constraints. Therefore, metaheuristic approaches have been used to find global optimum solutions to the long-term OPMPSP. This paper presents a metaheuristic approach utilising a dual interchange algorithm (DIA) to solve the long-term OPMPSP. The DIA is a parent algorithm which supervises two subservient algorithms, namely, simulated annealing (SA) and Tabu search (TS). The DIA selects the better solution generated in each run from the two algorithms, and simultaneously penalises the algorithm that produced an inferior solution, while rewarding the one that produced a better solution. The DIA was tested on the three-dimensional Arizona Copper Deposit (KD) dataset, which is publicly available for research purposes from the online MineLib repository. It was set to generate net present values (NPVs) in five-minute intervals and the solution improved until it plateaued at about 30 minutes of runtime. The NPVs compared favourably to those obtained on the same KD dataset but obtained over 24-hour runtimes, when solved using simulated annealing and Tabu search algorithms, and the NPV generated from the work of Muñoz (2012) using the modified TopoSort as found on the MineLib repository at the time of this study. Therefore, this paper demonstrates that DIAs can be developed and used to solve the three-dimensional long-term OPMPSP.

Sep 1, 2021

By L. Paulino, C. E. Zangiacomi, J. Yamamoto

"This paper presents the learning from Alcoa Po9os de Caldas Smelter in Brazil, after several energy restrictions resulting from the failures of three rectifier units at its power switchyard. Starting on December 27th, fuses and diodes failed in three rectifier units of Potline #1, causing a long and dangerous power interruption. Even after current was reestablished, amperage was only 70% of the line target leading to a bath freezing process that lasted for around 48 hours. The process engineering team played with several potroom parameters as pot resistance, bath and metal levels, alumina feeding and bath chemistry in an attempt to minimize impact on the potline metal output and energy consumption. As it will be illustrated, the first battle was to keep the pots running on a ""survival"" approach. After that, several changes took place on the procedures used to run at reduced current which were considered rather successful. Finally, some recommendations will be given to foresee and prevent transformers and rectifiers from undesirable failures."

Jan 1, 2006

By J. C. Mitcheson

Mr. President, Mr. Mayor, Ladies & Gentlemen: IT GIVES ME great pleasure to have the opportunity, today, to speak on behalf of all the constituent. bodies of the Common-wealth Council of Mining and Metallurgical Institutions. For the past month we delegates have been right royally entertained across the length and breadth of Canada by Provincial Governments, City Councils, and other equally generous public organizations and private corporations. On this occasion, however, the President of The Canadian Institute of Mining and Metallurgy, our good friend Dr. H. J. Fraser, has been our host at the enjoyable reception preceding this Institute Luncheon, which luncheon was sponsored by our official host, The Canadian Institute of Mining and Metallurgy, one of our .constituent bodies.

Jan 1, 1957

By Choon Kooi Quan

Water availability is essential for mining and minerals processing. To provide government and industry with recent data for water use planning and management, the Bureau of Mines canvassed a number of U.S. producers of nonfuel minerals to determine their water use in 1984. Data were analyzed and compared with previously published data in order to examine historical trends in water utilization in the nonfuel minerals industry and to estimate water requirements in the year 2000. Total water use in the domestic nonfuel minerals industry during 1984 was estimated at 2,267 billion gal, of which 571 billion gal was new water and 1,696 billion gal recirculated water. The largest users of water were the phosphate rock, iron ore, copper, sand and gravel, and crushed stone industries, together accounting for almost 90% of total used. More than one-half of all water was used in Florida, Michigan, and Minnesota. In the year 2000, total water use will amount to an estimated 2,679 billion gal, of which 810 billion gal will be new water and 1,869 billion gal recirculated water. Most of this water would be used in producing the foregoing suite of minerals,

Jan 1, 1988