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On 26 August 1971, the Bureau of Mines, through the Spokane Mining Research Center at Spokane, Washington, approved initiation of the evaluation of oscillatory energy toward enhancing flow of polymer into shale. The effort was an outgrowth of work performed under Bureau of Mines Contract H0210055, "Feasibility Study of Surface Impregnation equipment for the Chemical Stabilization of Coal Mine Structures," wherein feasibility of the impregnation concept was expressed and the detailed design of a machine for impregnation of coal mine roofs with polymer (under static pressure head) accomplished. Under these efforts, the potential enhance¬ment of polymer uptake into the shale thru superposition of oscillatory energy on the static impregnation pressure was suggested. A proposal for investigation of this phenomena entitled "Feasibility Study of the Application of Oscillatory Energy as an Aid to Afford Chemical Stabilization" was presented to the Bureau whereupon a three month program for initiation of investigation was approved.

Jan 1, 1972

By R. J. Gochin, M. A. Diaz

A modified Hallimond tube is described which allows the determination of the ultimate recovery R and the flotation rate constant k in a single, continuous experiment. The range of fine particles which can be satisfactorily floated with the modified apparatus can be extended by increasing the length of the bottom part of the tube. Findings suggest that pyrite and arsenopyrite can be separated in alkaline suspension using the so-called F series of collectors. Lime was found to act as a depressant. The collectors operate under pH and dosage control and do not require other depressants. Collectors used in the study were thio-amine (a cationic surfactant) and alkyl propionamide (a non-ionic surfactant)

Apr 1, 1995

By F. A. Jones

Increased mechanization .of coal mines has emphasized the need for study of actual power requirements of the various machines employed in the production of coal and losses in the distribution of power to these machines. These studies are being made in order that hazards, excessive use of power, and high maintenance cost of equipment resulting from these losses may be analyzed and eliminated where possible. Research on the use of electric power in-coal mines was suggested by the Advisory Committee of the Bureau of Mines in 1937, and it was decided to begin with a study of individual machines of various types under operating conditions in modern coal mines. The transmission of power, particularly line losses and inadequate return circuits, should be a part of the investigation. This report presents some of the data of an initial study in commercial mines. ACKNOWLEDGMENTS The superintendents, engineers, and other officials of the two mines studied cooperated fully and aided in setting up and transporting the test equipment, giving such information as was requested.

Jan 1, 1942

By Robert L. Lagace

A whole-mine experiment to assess the practical feasibility and utility of the dedicated-wire technique for overcoming poor trolley carrier phone system performance at a large underground coal mine was designed, performed, and evaluated. The technique involves the use of a single, low-loss, properly terminated and branched auxiliary wire placed in the rail haulageway. This auxiliary dedicated wire allows signals to electromagnetically couple to the trolley wire/rail transmission line, and thereby significantly decrease the overall signal attenuation rate on the trolley wire/rail line. The in-mine dedicated-wire demonstration program and its results, conclusions, and recommendations are described. The dedicated-wire technique is shown to be a valid and practical one for significantly improving carrier phone system performance in coal mines.

Jan 1, 1981

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1982 (October 1, 1980 -September 30, 1981) under its Minerals Health and Safety Technology program. Contingencies may require that a significant port ion of the program be deferred into fiscal year 1983. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the systems technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

The early development patterns of both Australia and New Zealand were substantially in parallel and both were heavily indebted to gold mining for, providing the stimulus to growth. However, since the mining boom, of 1895 - 1899, the mining sector in New Zealand has progressively declined, while in Australia it has assumed an increasing importance in the economy. The continued dominance of minerals in Australian trade, and the fact that eight out of the top ten companies in Australia are directly involved in mineral exploration and production, has strongly influenced government and public attitude's to the minerals sector. Although the legal framework of mining and exploration Acts and Regulations are similar it is in, the method of administration, particularly in regard to exploration and prospecting licences, that the gulf across, the Tasman is apparent. Despite the relative ease of application and granting of licences in Australia, in the more settled south eastern part of the continent we are finding more and more land is being zoned unavailable for exploration. In the remote areas, the Aboriginals now control nearly ten per cent of the land area of Australia, virtually with drawing that portion from exploration. The concept of 'Australianisation' has softened a hardening attitude against foreign investment in mining on the part of the bureaucracy. This anti-mining attitude is fortunately, not shared by the public, and we can but hope that the will of the Australian people can filter through to our masters in Canberra, and ease the rapid increase in the number of regulatory bodies which does so much to inhibit the normal conduct of business. The delays caused by interminable hearings and committee investigations all cost money. This cost can only rebound back on the end consumer, who after all is a voter.

Jan 1, 1982

By P. G. Pigott

The lack of technical information regarding the physical characteristics of kaolins and bauxitic kaolins, rejected during the mining of bauxite near Eufaula, Ala., has retarded their commercial utilization. This investigation was undertaken to determine their behavior when used in refractories. Ores were evaluated as refractory raw materials by compounding dry-press mixtures and specialties following procedures common to the industry. Products now on the market were used for comparison in laboratory evaluation.

Jan 1, 1959

By R. D. Joseph

This report deals exclusively with roof-fall accidents that occurred during 1955 and 1956 in both anthracite and bituminous-coal mines throughout the United States. The report stems from a cooperative study conducted by the Bureau of Mines and the Roof-Control Committee of the Coal-Mining Section, National Safety Council. The study includes an analysis of individual accident reports, sets forth the measurable factors, and compares such factors with a representative sample of average data from 39 anthracite mines and 117 bituminous mines (appendixes A and B). Particular emphasis is placed on fatal roof-fall accidents with respect to their causes, locations, and the methods of support used at the point of occurrence. INTRODUCTION The purpose of the report is to classify all measurable details of the occurrences of roof-fall fatalities so that the material presented will assist those promoting safety and will serve as a manual for those whose principal duty is inspection of mines.

Jan 1, 1958

By R. Altindag

In rock cutting mechanics, the effects of the rock and coal brittleness on the efficiency of cutting bits are examined by many researchers. There is no universally accepted brittleness concept as a measure of cutting efficiency. The effect of the brittleness on rock cutting has not been completely explained. The aim of this study is to correlate the relationships between Specific Energy (SE) and brittleness concepts. The applicability of various brittleness measurement methods for rock cutting efficiency has been investigated. In this study, the raw data derived from previous experimental studies were used, and the relationships between SE and brittleness concepts were investigated. The two previously used brittleness concepts, which are named as B1 (the ratio of compressive strength to tensile strength) and B2 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), and a new introduced brittleness concept named B3 (the area under line in relation to compressive strength and tensile strength) were evaluated in this study. The relations among these brittleness concepts for rock cutting efficiency were established using regression analysis. There is no correlation found between the SE values and the brittleness of B1and B2values. But, the SE is strongly correlated with the brittleness of B3. It was seen that the suggested brittleness of B3concept could be used as an indicator in rock cutting efficiency analysis.

Jan 1, 2003

By Noel Dent

The Electrodet@ Electronic Detonation System Wilere are we going with regard to Accurate, Reliable, Easy to Use and Cost Effective Initiation using electronic initiation techniques? Improvements and applications in theJierd

Jan 1, 1995

By Rodney D. Rosenkranz

The Bureau of Mines evaluated the potential supply of primary copper from domestic mines and deposits and found that increases in copper price will be required in order for many domestic deposits to continue production. As part of the study, a tonnage-price relationship was developed indicating the quantity of copper that could be produced economically from known deposits at various copper prices and at various rates of return on the required capital investment. Costs of production are based on estimated capital and operating costs for mining, concentrating, transporting, smelting, and refining. Direct and indirect operating costs, recovery of investment, and return on investment have been included in the smelting and refining costs. Capital and operating costs are calculated in January 1978 dollars, and byproduct credits are based on January 1978 prices. Known domestic copper mines and deposits contain nearly 92 million metric tons of copper in about 14 billion metric tons of demonstrated mineralized material. These tonnages represent the current domestic copper reserve base. Approximately 74 million metric tons of copper are recoverable from the reserve base using existing technology. Of this quantity, slightly more than 50 million metric tons are economically recoverable assuming a price of 51.00 per pound of copper, credit for the recovery of byproducts, and a 15-percent rate of return on capital investment. Approximately 60 percent of the copper occurs in mines that were producing at the time of the study.

Jan 1, 1979

By Kwang-Tae Kim, Yong-Kun Choi, Jeong-Soo Chong, Yun-Jae Lee

An annex building at the former Agency for National Security Planning(NSP) complex located in downtown Seoul was demolished by progressive collapse method. This work was done as a part of efforts to restore the landscape of Namsan Mountain which lies in the Center of Seoul. The five-story reinforced concrete structure was razed in 5.5 seconds by the 29kg of high powered explosives which were placed in some 320 holes in the building with floor area of 2,577 m². The asbetos and all the other finishing materials in the building were removed before the demolition and the specially coated wrap minimized the spread of blasting dust. Seismic and air overpressure waves were monitored at 8 points, which were below safety limits and the continuous communication with neighborhood prevented any complaint.

Jan 1, 1998

By A. M. Hill

"This is an account of the expansion of Texasgulf's Timmins concentrator by the building of a fourth circuit.The original capacity of the mine and concentrator was 3.6 million tons per year of ore. In 1974, Texasgulf decided to increase that capacity by about one third to 4.8 million tons per year. It was planned that the increased capacity would be available by mid-1978.The expansion involved work at the rninesite, increased railroad capacity, and a new circuit in the concentrator, and it is the concentrator expansion which is described here.In 1974, the minesite drew its ore from the open pit. The pit was being phased out and was to be replaced by No. 1 mine. To allow for the expansion, a second mine was required. The railroad was capable of handling 18 car trains. Its capacity had to be increased to 27 cars per train and this, in turn, required two new locomotives. Each of these alone cost half a million dollars.The concentrator building in 1974 contained the concentrating equipment and miscellaneous services (such as machine shop, warehouse, analytical lab). The grinding and flotation sections were divided into three circuits ('A', 'B', & 'C'). 'A' and 'B' circuits treated copper-zinc ore and 'C' circuit treated the much more difficult copperzinc- lead ore. This 'C' circuit had been modified over the years to implement improvements in the metallurgy."

Jan 1, 1979

By T. J. Yeomans

"The Kidd Creek metallurgical site is situated twenty-six kilometres east of Timmins, Ontario. The site consists of a 4.5 niillion tonne per year concentrator, a 127,000 tonne per year electrolytic zinc plant and a 79,000 tonne per year copper smelter/refinery complex.The concentrator commenced operations in 1966 and was expanded to its present capacity in 1978. The zinc plant commenced operations in 1972, and the copper smelter/refinery in 1983.The concentrator tailings, and both liquid and solid waste products from the other plants are disposed of within a 1215 hectare tailings disposal area. Here, a method known as centraljzecl thickened discharge is used to form a stable cone-shaped hill. A low permanent perimeter dyke structure encloses the cone and directs cone run-off and thickener overflow to a treatment pond. After treatment with lime slurry, this neutralized effluent is recycled to the metsite and also discharged into the Porcupine River system.The tailings system has been in operation in its present form since 1972, upon completion of dykes and a 110 metre thickener unit. Underflow densities were continuously increased until thickener overloading became a serious problem. This necessitated the construction of a second 110 metre thickener, which was completed in 1983. Target densities have been achieved without difficulty since then.This paper discusses the operation of the tailings system, reviews past performance, and outlines future operations."

Jan 1, 1986

By Q Johnston

Since its inception in 1990, improved metallurgical processing technologies, coupled with mine planning enhancements and improved geological knowledge, have sequentially enabled better efficiencies and economies of scale at the Macraes Gold Project. Over a period of 11 years, processing enhancements have been achieved by: +        increasing mill throughput, from one million tonnes per year, to current throughput of 3.9 million tonnes per year; +        improving recovery rates, from 70 % to approx 84 %; and +        performance enhancement through innovation, eg the use of kerosene to combat ClL pregrobbing. Future processing improvements have been identified in optimising the ore feed and processing flowsheet. The introduction of the autoclave has transformed the process flow form a traditional 'mill headgrade and tonnes milled' operation, to a 'sulphur/gold ratio and sulphur tonnes oxidised' operation.

Jan 1, 2001

By B. M. England, M. V. Swain, N. Bristow, R. D. Dukino

The toughness and fracture mechanisms of ores with significantly different microstructures from Yandi, Koolan and Mount Whaleback were studied with a view to understanding their degradation behaviour. Bulk fracture toughness was determined by the 3-point single-edge notch beam test and the results interpreted using Weibull statistical analysis; indentation fracture mechanics was also used to measure fracture toughness of the different mineral forms and to understand their response to contact fracture

Apr 1, 1995

By R. S. Dean

In general, the Division conducts investigations relating to the treatment of ores and metallurgical products from the condition to which they are mined to the refined metal. At the object of conserving natural resources and eliminating waste by furnishing information on current methods of metallurgical practice making fig fundamental studies of metallurgical processes and developing new processes and alloys to the point of demonstrating their or value. Office of the Chief Engineer The functions of the technical units of the Office of the Chief Engineer are indicates

Jan 1, 1941

By E A. Amaral Jr, A C. Chieregati, J C. O Souza

Cross-belt samplers are designed to sample particulate material in processing plants, usually when there is no space to install a conventional linear falling stream sampler. Most of the available cross-belt samplers are mounted on the top of conveyor belts, and remove each increment from a loaded moving conveyor with a 360° rotation of an open faced cutter, in a plane perpendicular to the material flow. Despite the practicality of this equipment and the fact that it occupies very little space in the plant, cross-belt samplers are well known for collecting biased samples, especially due to the increment extraction error. Sampling consultants around the world tend to condemn this sampling equipment, claiming that it is incapable of collecting the fine material from the bottom part of the load, and, since the sampling probability is not uniform for all fragments and depends on its position in the stream, this kind of sampler generates biased samples and its use should be avoided. Furthermore, the greater the segregation effect between particles, the larger the bias. However, some plants, whose initial design did not plan for the installation of a falling stream sampler, must rely on cross-belt samples for process control and reconciliation. For the past years, sampling equipment manufacturers have been putting effort in modifying the cross-belt sampler design in order to comply with the principles of correct sampling. Changes to the cutter material, shape, position, speed and movement in relation to the material flow have been made, and are continually being tested for different types of ore with various chemical and physical characteristics. This paper presents the improvements made to a cross-belt sampler at a gold plant feed in Brazil and describes the tests performed until it was possible to validate the new sampling equipment for reconciliation purposes.CITATION:Chieregati, A C, Amaral Jr, E A and Souza, J C O, 2017. Validation of a modified cross-belt sampler for reconciliation purposes, in Proceedings Eighth World Conference on Sampling and Blending , pp 247–254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Enterprise Optimisation is a methodology for increasing the value of mining and mineral processing operations through better long-term planning decisions. It involves a combination of ten mechanisms which deal with decisions at different stages of the value chain. A decision made at any point in the chain potentially affects the decision for all other points in the chain. The key, therefore, is to optimise them simultaneously. The Enterprise Optimisation approach can be shown to produce increases of five per cent to 35 per cent or more in net present value (NPV), even when several optimisation methods have already been applied. This paper steps through an example case study, illustrating the effect of each mechanism and how they can work together to develop greatly improved results. This example results in a series of counter-intuitive outcomes, which challenges conventional management practices and typical organisational objectives based on organisational silos.

Dec 6, 2010

By Roy S. Nutter

The automation of coal mining must occur in a manner that is economically beneficial to the industry and that enhances the safety of the underground and surface workplaces. The work at WVU over the last five years in applying expert systems and neural network controlled autonomous robotics provides the mining industry with tools that when properly applied should clearly lead to mine-wide management and operational improvements and should also contribute to a higher awareness of safety issues by all work crews. This work includes the development of MMSS (Mine Management Support System) and the detailed development of autonomous robotics utilizing neural networks for mining systems.

Jan 1, 1993