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By Roy C. Bartholomae

This Bureau of Mines report presents the results of a laboratory investigation of coal cutting mechanics and noise. These experiments were performed using linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts was ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to formulate analytical models of the coal cutting forces and noise. The analytical model for coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as provide benefits to other important areas of health and safety in underground mining.

Jan 1, 1983

By H. M. Lawrence

"The land-pebble district, the larger of the two producing areas of Florida, is situated in Polk County and in the eastern part of Hillsborough County. About 80 per cent at the phosphate rock produced in the United States in recent years has been mined from this area. The phosphate ores, locally termed matrix. are beds of sands and clays containing the phosphate pebbles, considered to be Pliocene in age, derived by marine action from underlying Miocene phosphatic marls, and are covered by practically barren sands and clays that have been deposited more recently. Open-pit mining is practiced; hydraulic mining, which has been intensively developed in this district, is used exclusively for mining the matrix and, by some companies for removing the overburden, although drag-line excavators have become established and are proving economical for stripping operations. From the pits the matrix is pumped to adjacent washing plants for beneficiation. The product of the washers. after drying, enters the world markets as Florida pebble phosphate.In this district recovery of the phosphate pebbles by the washing plants has not been particularly effective in the past. The screening, designed to effect a seperation at about 20 mesh (0.033 inches), has not been well controlled. Washer rejects discarded to the waste dumps have contained appreciable amounts of material analyzing above the minimum commercial grade - 66 per cent B.P.L. (bone phosphate of lime). Such losses of commercial fractions should be considered avoidable, and have been discussed at length in a previous paper.3"

Jul 1, 1930

By S. K. Chan, C. Badeen, S. Goldthorp, H. Feng, I. Alilovic, R. Turcotte

Over the last few decades, water-based explosives and their precursors, despite their apparent insensitivity, have been involved in a number of accidents around the world. A large proportion of these accidents occurred when these emulsions were pumped either for their manufacture, transport, or handling. In Canada, this has led to the development of “Guidelines for the Pumping of Water-Based Explosive”, which state that “using pumping pressures well below the laboratory measured minimum burning pressure (MBP) of the corresponding emulsions or watergels is a good safety practice”. However, in the above document, there is no description on how the MBP should be measured. In the last few years, a research program at the Canadian Explosives Research Laboratory (CERL) in collaboration with Orica has been focused on the development of a validated measurement protocol for realistic MBP measurements.

Jan 1, 2014

By W. M. Cross

Bubble attachment time measurements for the rare-earth phosphate minerals monazite and xenotime were made as a function of oleate concentration, sodium fluoride addition, and temperature. Results indicate that the rare-earth phosphates behave similarly to other phosphate minerals, notably collophanlte and fluorapatite, which have been studied previously. The addition of sodium fluoride yielded a modest decrease in bubble attachment time with fluoride additions below the apparent fluoride surface precipitation point, while at fluoride additions greater than the apparent precipitation point a significant decrease in attachment time occurs. Increasing the temperature or the system gave a slight decrease in bubble attachment time in the absence or sodium fluoride. With sodium fluoride addition and below the apparent fluoride surface precipitation point, an increase in temperature actually increased the attachment time. For sodium fluoride additions above the apparent fluoride surface precipitation point, a temperature increase significantly decreased the attachment time.

Jan 1, 1989

By Gary Almeraris, Vincent Jr Tirolo

Traditionally, “Means and Methods” were the sole responsibility of Contractors. However, because of a number of litigious projects in the 1970s, Owners and their Engineers began including Suggested Methods of Construction (SMC) in Contract Drawings. By the late 1990s these SMCs were becoming baseline “Means and Methods” with Contractor recommended changes often considered as Value Engineering proposals. By 2004, the word “Suggested” was sometimes changed to “Prescriptive.” Owners are also purchasing TBMs and other mining equipment for Contractors prior to bid. Is limiting the contracting community’s innovation in developing their own “Means and Methods” and selecting their own equipment in the best interests of the Owner? Does it reduce the Owner’s, Engineer’s or the Contractor’s risk? Are claims reduced and finally what is the impact on the bid? A questionnaire was sent to more than fifty senior engineering field and management personnel representing more than 30 heavy construction companies to ask their opinion on these questions.

Jan 1, 2005

By Arno C. Fieldner

The determination and publication of data o the chemical and physical properties of American coals have been primary functions of the Bureau of Mines since its creation in 1910. In recent years this program has been expanded to meet increasing needs for information on the suitability of coals for the production of coke, gas, and byproducts, and within the last year an experimental coal-hydrogenation plant has been completed. With this addition, the Bureau is able to cover every phase of coal utilization, including combustion, carbonization, liquefaction, and complete gasification. The need for this information is increasing not only to meet the requirements of consumers but also to give the data required to establish the classification and minimum selling price of coal by the National Bituminous Coal Commission.

Jan 1, 1938

By Toshiharu Teranishi

When we apply the Au nanoparticle superlattices to the future nanooptical and nanoelectronic devices, the control of not only the particle size but also the interparticle spacing and symmetry of superlattice are the essential problems to be overcome. First, we developed a novel synthetic procedure to precisely control the particle size of alkanethiol-protected Au nanoparticles in the range from 1.5 to 9.7 nm by the heat-treatment of the small Au nanoparticles in the solid state. Absorption and nonlinear optical properties of alkanethiol-protected Au nanoparticle superlattices were then elucidated. On the other hand, the hexagonal close-packed (hcp) 2D superlattices of small Au nanoparticles with the interparticle spacings from 1.9 to 3.6 nm were successfully prepared by using newly-synthesized ligand for single electron tunneling devices. Finally, various symmetric superlattices, such as chain (2-fold), quasi-honeycomb (3-fold), square (4-fold), etc., of Au nanoparticles could be produced by making use of interligand interactions or some templates.

Oct 1, 2003

This modern plant consists of a battery of 72 Otto Wilputte Compound Under-jet Ovens with extensive plant for the recovery by-products. The ovens produce 9000 tons of furnace coke per week together with some 17,000,000 cub. ft. of coke oven gas, which is used for heating purposes throughout the works and for heating the ovens.Coal is supplied from the, company's colliel'ies and is stored under a Coal Handling Bridge of 264 ft. span and 365 ft. overall, capable of handling 250 tons per hour. The coal storage space of 1600 ft. can. be extended to a maximum of 2800 ft.Preparation of the coal for coking involves fine grinding which is carried out as follows:-Coal is dumped from rail waggons on to a conveyer belt which delivers it to a 12 ft. x 22 ft. Bradford Breaker, with a capacity of 400 tons per hour. The coal, then approximately 4 in. in size, passes, to the mixing bins; and after careful blending is reduced in the,hammer mills to a fineness suitable for the ovens.The fire coal is elevated to the main storage bin over the battery for subsequent charging by electric larry car. The average cokingtime is 15 hrs. 36 mins. At the end of ,this period the doors, are removed and the coke pushed from the oven by a mm. The coke, is, then quenched with fresh, water and sent to the Blast Furnace in 50-ton Copper Waggons.The gas is exhausted from the ovens by Brown Boveri turbine, exhausters of 23,000. cub, ft, per min. capacity. Exhaust steam from these is used for various. purposes in the By-Product plant. After removing the last traces of tar by Electrostatic Precipitators', the gas is bubbled through sulphuric acid, the ammonia forming ammonium sulphate, which is subsequently washed, dried and bagged for sa,le as a fertilizer. The gas then goes to the Benzol Scrubber Towers, where benzol and other derivatives are recovered and later redistilled and purified. The cleaned gas is then piped to the main works for heating purposes, being used with tar to fire the steel furnaces, and also the soaking pits and reheating furnaces.BLAST FURNACES.The company is at present operating two Blast Furnaces of 800, and 1000 tons nominal daily capacity respectively. The latter was...

Jan 1, 1938

The addition of cement to underground backfill at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited, Broken Hill commenced in 1967. A deterioration in metallurgical performance at each concentrator occurred as a result, with increased loss of lead and zinc to residues. Investigations to determine the reasons for this problem and methods to counteract it have been undertaken. This paper outlines the effects of cement on lead-zinc beneficiation at Broken Hill and presents an interim report on attempts to overcome the metallurgical deterioration.

Jan 1, 1971

By A Bax, G Wardell-Johnson, A Giblett, W Staunton

This paper presents a number of key considerations for process development testwork as a reliable basis for the inclusion of gravity separation in gold recovery flowsheets. Operating data, experiences and numerous case studies are also discussed in support of identifying best practice principles for gravity circuit design.CITATION:Giblett, A, Bax, A, Wardell-Johnson, G and Staunton, W, 2013. A review of best practice in gravity circuit design and operation, in Proceedings MetPlant 2013 , pp 272-284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Parry. V. F.

"INTRODUCTION Coal is a compressed mass of heterogeneous, macerated, metamorphosed plant remains that have collected in the earth's crust. Probably no two beds of coal have identical properties, and different parts of the same bed may vary considerably when measured by some of the many empirical tests that have been developed to classify or differentiate the properties of coal. Because of this great variability in properties, the commercial processing of coal to produce coke and byproducts has developed largely as an art based on experience, rather than as a science. Much empirical chemical research, however, has been and is being conducted on coal carbonization, and this work is of practical value in obtaining larger yields of gas and byproducts and in the improvement of the physical properties of the coke.Both ultimate and proximate analyses have been used for correlating purposes. 3/ In the United States the proximate analysis is used for the classification of coal according to rank and grade. The proximate analysis can be employed usefully in the coal—carbonization industry because separation of the combustible matter of coal into volatile matter and fixed carbon is, in fact, a small carbonization test conducted on 1 gram of coal heated in a platinum crucible.Small—Scale Laboratory Coking Tests,Many empirical tests have been devised for determining the coking properties and measuring the yield and quality of gas and byproducts obtainable from various coals. These tests, made on samples ranging from 25 grams (about 1 ounce) to 5 kilograms (11 pounds), furnish information that is roughly proportional in practical value to the size of the sample carbonized. However, the cost of the carbonization test also increases with the amount of the sample, so that for preliminary surveys of a number of coals, samples of 25 to 1,000 grams usually are employed."

Dec 1, 1939

"INTRODUCTION Early in 1936 the Interstate Oil Compact Commission and other groups interested in forecasts of demand for petroleum requested the Bureau of Mines to make a physical inventory of crude-oil stocks in the United States, Accordingly, the 74th Congress appropriated funds for conducting such a survey during the fiscal year ended June 30, 1937. In the discussions and hearing 2/ relative to the need for the survey, the opinion was expressed that crude oil held in storage for long periods had lost so much of its gasoline content that the economic significance of total stocks should be discounted materially. Therefore, a primary objective of the survey was to make a physical inventory of the crude oil held in storage above ground and to determine the quantities and characteristics of the light fractions contained in the various stocks."

Sep 1, 1938

By Han Yi

The coarse indium ingots produced by Shaoguan smelter contained a lot of impurities. In order to produce the high pure indium with the purity more than 99.99%, the appropriate refining processes were designed and the practice of combined application of Glycerin-KI process and electrolysis in Shaoguan smelter was introduced.

Jan 1, 2005

By R. H. Fernald

In 1900, as far as available records show, there were only two producer-gas power installations in the United States. In June, 1915, the number probably exceeded 1,000. Of this number, some 84.5 per cent comprised small plants using anthracite, and only about 15 per cent of the total number utilized bituminous coal and lignite. In addition to these, two plants used wood, and three or four used oil. In the main, however, the larger sized units are operating on bituminous coal and lignite.

Jan 1, 1916

By J. -F. Lagueux

Goldex Mine is an underground mine located near the town of Val-d?Or. Multiple innovations were required to work the mine. Due to its low grade, it was important to develop a bulk mining method to economically extract the ore. The method used is a combination between shrinkage stope and long hole stope methods. This modified method is more than adequate; however, all of the ore body must be liberated in a very short period of time. Therefore, to bring down 23 Mt of ore, large blasts up to 1.8 Mt are required. The situation is also complicated by the fact that the mine is located in a residential area. No less that 40 homes are built within a 1 km radius of the mine site. In addition to managing mass blasts, means must also be found to mitigate the vibrations produced by the blast to diminish the disturbance to the neighbourhood. Therefore, the mine used numerous tools to properly plan the blasts and reduce the impacts. A program to control vibrations was one of the first tools put in place. The program?s aim was to draw up an action plan to ensure a follow-up of the homes by inspecting them. The second tool was to develop a methodology to plot a reliable attenuation curve and to adequately determine the maximum charge weight for each blast. Finally, effective communication tools were developed to inform the neighbourhood. There was a huge amount of work to be done in relation to the bench. Reliable and fast loading techniques had to be found to load large blasts in a very short period of time. Adequate logistics had to be developed to send underground more than 20,000 kg of emulsion per day while performing the daily underground operations. Technology had to be developed to adapt the i-kon electronic blasting system to large blasts. Since the control of the charges was the major factor to reduce surface vibrations, it was important to employ loading techniques that would permit decking of the long holes to reduce the charge weight per delays without adversely affecting the loading. All of this work requires an enormous amount of energy but also close collaboration between the different stakeholders (various departments, suppliers and consultants).

Jan 1, 2011

By S. A. Luciani

"In 1957, an asbestos orebody was discovered in the northern sector of the Ungava Peninsula of the Province of Quebec, an area now identified as Asbestos Hill. The deposit is situated on a plateau 1700 feet above sea level and 42 miles inland from Hudson Strait. It is a bleak, iso. lated location of typical arctic environment. Fifteen years were to pass before the first shipment of ungraded fibre was made in 1972. These years we1•e occupied with field surveys and investigations, diamond drilling, engineering design, evaluation of investment and operating costs, and construction. The problems normally associated with mine development were further complicated by location, isolation, and the extreme cold and permanently frozen ground of the arctic regions. Unique to an isolated arctic operation are the organization of support facilities and services, procurement and retention of personnel, construction of access roads and airports, and scheduling of product out and supplies in during the short summer period of sea navigation."

Jan 1, 1976

Being a geologist I intend describing the renaissance of the gold industry in Australia within its geologic framework; there is a geological pattern to the numerous gold projects which have been brought on stream over the past decade. We are now about midway through our third and largest gold boom which, at a peak of 7.5 million ounces is about twice the production peaks achieved in the preceding booms. From discovery in 1851 through 1870 we saw the first boom largely based on alluvial production in NSW and in Victoria at the great Ballarat and Bendigo Goldfields. The discovery of the Golden Mile in Kalgoorlie, Western Australia, underpinned the second gold boom in the period 1895 - 1915. On that basis the present boom should last through the next decade.   It has been a golden decade for Australian gold production. From less than ten mines in 1980 with production over 10 000 ounces and the largest, Telfer, with output of about 130 000 ounces we now find over 130 deposits being worked around the country today that produce over 10 000 ounces with the largest, Boddington, having an output of over 400 000 ounces. In total these mines produced an estimated 210 tonnes of gold in 1989 and we expect this year, 1990, that a new record production of between 240 and 250 tonnes will be set. This positions Australia in third place in the Western World behind South Africa #1 and the USA #2 and fourth in the world with the Russians holding second place overall behind the South Africans.

Jan 1, 1990

By J. A. L. Napier

This paper presents an overview of work carried out by the CSIR Division of Mining Technology and formerly by the Chamber of Mines Research Organization (COMRO) to quantify the behaviour of the stope fracture zone near deep level goldmine stopes. The motivation for this work is first reviewed in the context of the unsatisfactory status of current mine layout design criteria. Numerical methods to represent failure processes are reviewed briefly. Specific studies of microfracture processes are described as well as physical modelling experiments that can yield insights into deformation mechanisms. Modelling of stope scale deformation mechanisms are presented and considerations relating to elastodynamic modelling of the rock mass are described. The implications of this understanding in relation to prospects for active fracture zone ?engineering? are outlined and finally, the directions of future research work are proposed.

Jan 1, 1997

By M. K. Abd El-Rahman

A complete chemical analysis of the waste showed that it contains 15.64% P2O5; X-ray diffraction analysis revealed that it is composed mainly of francolite, calcite, pyrite, quartz and dolomite. The phosphate values were recovered and the settling rate of the wastes enhanced by the use of hydrocyclone and flocculation techniques. The hydrocyclone produced an underflow enriched in phosphate and an overflow enriched in clays. The former represented 39.8% by weight of the phosphatic clay waste and assayed 26% P2O5 at a recovery of 66.36%. The results of flocculation of the phosphatic clay waste showed that both the degree and rate of settling were increased and that the process water could be recycled. The settling rate was 37 times greater when anionic polyacrylamide A130 was used

Jun 21, 1905

By A. Tobey Yu, W. Joseph Schlitt, Alfred Weiss, Frederic L. Kadey, Louis Kuchinic

Introduction The February and April 1984 issues of MINING ENGINEERING have already provided introduction to the long-range planning efforts of the Society of Mining Engineers (SME). These efforts are intended to provide the basis for effectively maintaining and improving the Society in the face of the changes that are besetting the mineral industry. This requires that SME recognize what changes are occurring and determine how these will impact the membership. Then a plan must be developed and implemented so that the Society successfully meets the challenges of the next decade. The Board of Directors has charged the Long Range Planning Commission with the responsibility for meeting these goals. This article provides a summary of the work done by the Management and Organization Committee of the Long-Range Planning Commission. This committee's task was to analyze the Society's current organizational structure and management process. Then a set of recommended improvements was to be developed. In doing this, the Committee has been careful to operate under that popular axiom, "If it ain't broke, don't fix it." Thus, changes were not proposed simply for the sake of change, but only where the present system appeared to be less effective than desired. Bases For Action The Committee began by establishing a set of premises about SME and its membership. These premises provided the bases for subsequent actions and recommendations by the Committee. Highlights from the premises included: • The Society should be run on a business-like basis. However, its "business" is that of a not-for-profit scientific, technical, and educational public institution. SME enables professionals involved in or associated with the mineral industry to serve the public purpose of benefitting mankind. • The Society operates as a national (US) organization with transnational (worldwide) interests. It recognizes its obligation to make its goods and services available to minerals professionals throughout the world. In addition, the Society recognizes its obligation to translate technology for the "lay" public, who then also become users of its goods and services. • The Society's Board of Directors is the policy-making body of SME and has final approval of all programs. These responsibilities will become greater when the Society becomes a separate corporation. • At present, the Society provides the following goods and services: publications, meetings/programming/short courses, academic education support, information dissemination - internal and external, and individual member services. • Planning is an ongoing process. It is best performed on a decentralized basis. That is, each major service category should have a responsible group authorized to conduct planning for that category, subject to the Society's master plan and the Board's approval. • The Society is privileged to have highly qualified and motivated members who volunteer their time and efforts on behalf of the Society. The best of these volunteers should rise to the highest positions of leadership - the Presidency of the Society and Institute (AIME). • The Sooiety is strongly committed to the protection and promotion of the history, traditions, and identity of AIME and the use of AIME as the unifying forum for the Constituent Societies. Identification of Potential Problems Once the premises about the Society and its membership were well in hand, the committee began examining the many facets of SME's organizational structure and management process. This was done in order to identify problems or potential problems in these areas. After considerable review and discussion, 10 areas of potential concern were called out for more detailed study and possible recommendations for improvement. These 10 areas include: • A lack of continuity at the Board level and among officers due to the established turnover policy. • A series of subboards that serve, by practice, to diffuse management authority and accountability, rather than enhance it. • A question as to whether the dissemination of information has been adequately planned, organized, and staffed. • An apparent illogical divisional organization. Two divisions are discipline oriented and two are commodity oriented. • A regional organization that does not adequately fulfill its purposes. • Uncertainties about the per-

Jan 6, 1984