Search Documents

Much attention in controlling blast vibrations has been centred on the probability of causing damage to structures in the area adjacent to where blasting is carried out. In most cases these structures are residential properties and the effect of the vibrations on the occupiers has not been studied to any great extent. This paper looks at the sources of disturbance caused by blasting and their psychological effect. A comparison of ground vibration levels for compliance is examined within the framework of structural and human response.

Jan 1, 1998

Geophysical Abstracts 1 - 83 were issued in mimeographed form by the Bureau of Mines; Abstracts 87 - 111 were published in bulletins of the Geological Survey. Abstracts 112 and 113 were issued in mimeographed form by tine Bureau of Mines as Information Circulars 7256 and 7257. 1. GRAVITATIONAL METHODS 7004. Campbell, R. B. Florida's Geological Structure and Gravity. Proc. Florida Acad. Sciences for 1540, Gainesville, Fla., vol. 5, 1541, pp. 73-84.

Jan 1, 1943

By Federico Pagliacci, Marco Chiarabelli, Salvatore Miranda

The paper describes the adopted technologies and performance controls related to a special geotechnical engineering solution provided within the scope of the Galataport Project, in Istanbul, Turkey. The scheme is the one applied to the new quay of Salipazari, which is a combination of retaining structure and ground improvement, formed by a combi-wall, a reinforced concrete diaphragm wall and a soil improvement by deep soil mixing (Turbojet). The paper highlights the importance of employing cutting-edge technologies within the foundation engineering field and state-of-the-art electronic control devices, in parallel with the essential human expertise, in order to obtain the desired results in this high profile Project. The results of the in-situ and laboratory tests carried out on the improved soil are also presented. Main discussed points are: • History of Galataport and main Project details. • Design principle and soil condition for the new quay of Salipazari. • Difficulties encountered during execution of DSM. • Preliminary field trial tests conducted to establish the operational parameters, with relevant in-situ and laboratory tests executed. • Preliminary tests on material used for DSM (seawater and CEM IV SR). • Electronic equipment mounted on the rig, which allows the automatic execution of DSM columns. • Final QA/QC tests conducted to verify the performance of DSM, mainly consisting in: coring with relevant laboratory tests on samples (UCS + Es), seismic refraction tomography and seismic cross hole tomography. Correlations between UCS and Es, and between Es and Edyn are also presented. • A cross section of the executed treatment could be inspected on site during excavation. Photos and considerations are also presented.

Jan 1, 2018

An underground mine disaster is an accident of major proportions that takes a significant toll in human lives. A disaster usually disrupts the normal functioning of a mine and may result in entrapment of miners whose normal egress from the mine is cut off. A disaster often necessitates a rescue operation and a means of keeping the trapped miners alive while they await rescue. Explosion, fire, inundation of water or toxic gases, and collapse of a major portion of a mine are among the causes of mine disasters. Miners threatened by such an occurence must either bring the situation under control (e.g., by extinguishing a fire) or remove themselves from the danger. If control is unsuccessful, they must retreat to a place of safety. Four different activities may be involved: evacuation, escape, survival, and rescue. Evacuation is the orderly exit of people from the mine using previously identified escapeways and following a previously determined evacuation plan. Miners whose normal evacuation routes are blocked may be able to find alternative exit routes and escape by their own efforts. For those who cannot, the issue becomes survival while waiting to be rescued. The survival period may last for many days while rescue efforts are mounted from outside the mine.

Jan 1, 1981

"Use of the Bond Work Index to size industrial grinding equipment was widely known. Bond also described its application for measuring grinding circuit efficiency. Bond Work Index efficiency has been widely used by industry, but until now without concise standard methods, or a formal guideline, for doing so. The Bond Efficiency Sub-Committee of the Industrial Comminution Efficiency work group of GMSG has produced such a guideline, which follows. It covers the methods and provides examples of how to calculate the Bond Work Index Efficiency of most industrial grinding circuits. Bond Work Index testing equipment and methods are also provided. The next steps are: (1) to establish standard reference testing materials and one or more laboratories to serve as bases for reference testing; (2) to establish the accuracy of relative circuit Work Index Efficiency determinations; and (3), to develop and provide a public data base of industrial comminution circuit Bond Work Index Efficiencies. OUTLINE Introduction and Background Part 1. Determining the Bond Efficiency of a Grinding Circuit Method Demonstration/Example Calculations Bond Work Index Testing Equipment and Procedures Accuracy of Comparative Circuit WI Efficiency Determinations (under development) List of Symbols Part 2. Data Base of Bond Grinding Circuit Efficiencies (under development) References Annexes: A1. The Bond Crushing WI Test Equipment and Procedure for Bond Efficiency Determinations (Revised March 26, 2015) B1. The Bond Rod Mill WI Test Equipment and Procedure (Revised March 26, 2015) C1. The Bond Ball Mill WI Test Equipment and Procedure (Revised March 26, 2015) Introduction and Background Please see the references and slide presentation “Bond Efficiency SLC (rev3)-print.pdf.” This efficiency determination applies to most brittle materials in their naturally occurring (un-scalped) size distributions being treated in size reduction circuits down to a product sizing of approximately eighty percent passing 70 µm (see below). Unusually shaped materials (e.g. mica) should be regarded with caution. Part 1. Determining the Bond Efficiency of a Grinding Circuit Method In the plant: • Define the circuit for which the WI efficiency is to be determined • Procure samples of the circuit feed and product • Obtain the power draw of the size reduction equipment at the drive pinion(s) • Obtain the circuit throughput rate (dry tonnage) In the laboratory:"

Jan 1, 2016

"The characterisation of resources and description of variability across different ore domains is key to accurate prediction of probable metallurgical performance. Such characterisation testwork often has limited drill-core from which to work and this immediately confines the characterisation method to smallscale. For flotation feeds, the JKMSI (Mineral Separability Indicator) is being developed as a potential characterisation tool, building on earlier work by Chudacek, (1990), which used shaken test tubes, and was called the EMDEE device. In addition, the consistency of flotation recovery for specified size fractions has shown to be preserved, irrespective of the amount of material in that size fraction obtained by different milling conditions, so that the overall recovery can be estimated from knowing the particle size distribution (McIvor and Finch, 1991; Bazin et al, 1994, Runge, 2007 and Wightman et al, 2010) The JKMSI unit uses less than 10 g of material per test in narrowly sized classes and results to date have demonstrated the value of the test. This paper discusses the potential of the test by demonstrating the link between JKMSI performance and mineralogy of five different ores from Laguna Seca, Escondida Minera Limitada as well as the correlation to plant scale performance obtained in an earlier survey (Coleman et al, 2006). Further work to tie down the proof of representatively of the small sample has been identified and is discussed and included in the paper. INTRODUCTIONSince the uptake of the flotation process at the turn of the twentieth century, small scale, laboratory methods have been sought to characterise flotation response. Although laboratory batch flotation tests are the most widely used method to evaluate reagents, characterise ore variability and obtain suitable model parameters using various scale up factors Runge (2101) other methods using less ore would be useful where ore samples were limited.A method using test tubes for testing ores’s flotation response to reagents was first developed by Ian Walk (Wark & Wark, 1935; Wark; 1938; Sutherland and Wark 1955). In these tests a 50 cc stoppered measuring cylinder served as a means for a qualitative experiment, the aeration being effected through violent shaking by hand. In these experiments about 10 g of mineral was ground by pestle and mortar under water after which the ground material was deslimed and adequately conditioned with the appropriate reagents."

Jan 1, 2013

By John H. Soulé

This paper describes the location and general features of the ?Red Bed? or sandstone copper deposits in southeastern Colorado and New Mexico. Most of the areas containing this type of deposit were visited, and many deposits were examined. Some deposits were not visited because of lack of information as to their location. In the large area covered a great variety of climatic, geographic, and topographic conditions exists. Some of the deposits are in arid areas, whereas others are in heavily forested regions. Altitudes range from 3,400 to 9,200 feet, and the terrain varies from flat plains to rugged mountains. Transportation is a difficult problem in most of the districts, involving long truck hauls to a railroad and long rail hauls to a smelter.

Jan 1, 1956

By F. K. Shelton, J. C. Stah, Ruth E. Churchward

A study of the hydrometallurgy and electrowinning of cobalt from various domestic ores has been in progress at the Boulder City, Nevada, Experiment Station since February 1940. Previous reports covering certain phases of this investigation have been published. This report covers the research and pilot-plant work on the production of cobalt metal from cobalt-copper ores from the initial experimental work on crude ore through continuous operation. The ore types were from the Blackbird District, Lemhi County, Idaho. The initial tests were made with concentrated ore which was received by air mail and these experiments were expanded both in size and scope. After the laboratory was continued, improved, and extended tests were reported. Sufficiently advanced, a continuously operated plant producing 250 pounds of electrolytic cobalt per day was operated from June 15 through July 15, 1944.

Jan 1, 1948

By Carl Sunderman, Steve Signer

Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed several new tools for evaluating roof support performance. A miniature data acquisition system (MIDAS) was developed that can collect readings from up to 16 strain gauges at regular time intervals and store the readings for later retrieval. Three LED lights change from green to yellow, then red, based on the reading levels and/or rates of change of rock movement. This feature can be used to warn miners of rock instabilities. The system can be used with any strain-gauged support (resin bolt, friction bolt, cable bolt) or with a newly developed rock strain strip (ROSS) developed by NIOSH to measure rock strain. A ROSS is grouted in a hole drilled adjacent to the rock support to be evaluated; the deformed shape of the ROSS provides anchorage on either side of the strain gauges. Data from both laboratory tests and field evaluations are presented that describe the capabilities of both the MIDAS and ROSS instruments.

The Upper Waimangaroa mining permit is part of the Buller Coalfield and lies on the eastern side of the Stockton-Denniston Plateau. The mining permit area is estimated to contain a total in-ground coal resource of 58 million tonnes, contained within 13 separate coal resource .blocks. The coal is Bituminous High Volatile B rank with export potential as semi soft coking or thermal coal. The Northern Opencast mine is the first mine proposed for Upper Waimangaroa and consists of the three resource blocks at the northern end of the permit area. The highwall of the mine will cut into the Mt William Range resulting in overburden cover of up to 150 metres in some areas. The ability to rehabilitate the area after mining was a major consideration in the design of the mine. The Northern Opencast area has been geologically mapped, extensively drilled and effectively modelled using Vulcan software. Three distinct coal seams are present and the mineable in situ resource is estimated at 8.7 million tonnes of which approximately 7.1 million tonnes is likely to be recoverable. It is proposed that this resource will be mined using opencast methods and the void will be backfilled with overburden. The life of the mine is at this stage estimated at 19 years based on an annual production of 500,000 tonnes at 1.8% sulphur and the Upper Waimangaroacoal will be blended with low sulphur coal from the Greymouth Coalfield to meet export specifications. The Northern Opencast area contains a range of native flora and fauna and physical features which make it an environmentally significant area. Mining will totally modify the area, thus an effective rehabilitation scheme is an integral part of the mine plan. Various rehabilitation methods will be used, and wherever possible, the backfilled areas will be rehabilitated so as to resemble the original area as closely as possible.

Jan 1, 1998

By Ruth F. Brinkley

This circular describes the activities and publications of the Bureau of Mines, Explosives Research Laboratory4 for the fiscal year 1960 (July 1, 1959 -June 30, 1960). Part 1 describes briefly the principal projects that were active during the report period, and presents some data not scheduled for publication elsewhere in the near future. Certain of the results are only preliminary and should be regarded as tentative, pending the findings of the completed investigation. Publications that appeared during the report period are listed and described briefly in part 2. In general, the research activities reported in these publications antedate fiscal year 1960. The published material relating to activities that are still current is indicated by references in part 1.

Jan 1, 1962

James Barnes is Managing Director of James Barnes & Associated Ltd which is a company that has invested ten years of development to provide developers with a transparent, user friendly consultation framework that identifies who needs to be consulted, how they are to be consulted and procedures required to manage the risks associated with getting all the wrong! Despite the assertion above, this paper is not about to provide delegates with the answer to whom they ought to consult or identify the expectations that Maori might have in regard to the consultation process. It would be a very brave person indeed who would venture an opinion on such a sensitive subject. There are no short cuts to finding out what expectations Maori might have on any given situation. Nothing can be taken for granted. What this paper will attempt to do however is provide practical insights into what might be on the minds of Maori interests as they deal with the issues associated with mineral resources, particularly those under Treaty of Waitangi Claim. The Treaty of Waitangi has a significant bearing on the current debate between Maori and the Crown regarding ownership of mineral resources in New Zealand. The Waitangi Tribunal is currently hearing a case presented by a number of Iwi over the ownership of oil and gas resources in Taranaki and Hawkes Bay. Others will follow. The Crown and Maori have never been able to settle differences over ownership rights without resorting to legal action and it looks like this scenario is about to be repeated in regards to minerals. The Crown has a duty to actively protect the Maori interest. This is a fundamental expectation in the relationship between Maori and the Crown. In the case of minerals, Maori have yet to see the Crown do its duty. The impact on developers has become evident through Maori objections to consent applications as the issues of mineral right remain unresolved.

Jan 1, 2000

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.Low-sulfidation epithermal gold mineralisation at Ridge Mountain occurs within the Oligocene to Miocene volcanic rocks comprising andesite, porphyritic dacite and diatreme breccia. A diatreme breccia complex with a NE–SW elongated orientation covers an area of 3.0 × 1.7 km. Four main stages of mineralisation were identified, comprising: E–W- to NW–SE-trending quartz-chalcedony veins with disseminated pyrite, chalcopyrite and gold. N–S- to NNE–SSW-trending breccia veins with quartz matrix and disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold. NE–SW-trending quartz and calcite veins with disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold. ESE–WNW- to ENE–WSW-trending quartz veins with disseminated pyrite. This stage is only mineralisation that is hosted by diatreme breccia and clearly postdates.Quartz veins of the first, third and fourth stage are less than 2 m wide. Only breccia veins of the second stage are up to 10 m wide. Gold is present in all stages as microscopic inclusions in quartz and sporadically in pyrite. Macroscopic gold can be seen in the first and second mineralisation stages. Gold commonly occurs in association with sphalerite, galena and chalcopyrite in the second and third mineralisation stages.CITATION:Kucera, J, 2015. Diatreme breccia-hosted epithermal gold deposit at Ridge Mountain, eastern Mindanao, Philippines, in Proceedings PACRIM 2015 Congress, pp 587–592 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By C. O. Lee, Z. W. Bartlett, R. H. Feierabend

The Grand Isle sulfur mine is located in the Gulf of Mexico, approximately seven miles off the coast of Grand Isle, Jefferson Parish, La. The deposit is on acreage covered by oil, gas, and mineral leases originally issued in favor of Humble Oil & Refining Co. by the State of Louisiana which were continued, maintained, and redesignated by the U.S. Department of the Interior after passage of the Outer Continental Shelf Lands Act. The sulfur deposit was discovered in 1949 when Humble Oil & Refining Co. penetrated more than 200 ft of sulfur-bearing limestone in a zone between 1813 and 2075 ft below sea level. In 1954, Humble drilled ten more sulfur prospect holes, eight of which encountered sulfur ore. On September 19, 1956, Freeport Sulphur Co. acquired from Humble Oil & Refining Co, the sulfur rights underlying the tracts, and the actual design of the installation began the same month. The first structural contract was awarded in December 1957 and offshore erection began in June 1958. The initial phase of construction has been completed and production by the Frasch process commenced in April 1960. The estimated total cost of the project is $30 million, of which $8 million is the extra cost incurred by the necessity of offshore operations. More than $22 million was expended before production was started. GEOLOGY OF DEPOSIT Grand Isle is the third largest sulfur deposit in the U.S. The orebody embraces several hundred acres, but its outer limits are yet to be defined to the northeast, east, and south. Most Gulf Coast sulfur deposits occur in a caprock mantle of calcite (referred to as limestone), anhydrite, and occasionally gypsum, which covers the apex of an intrusive mass of salt. Commercial quantities of sulfur are usually confined to the calcite or limestone member. Most often such limestone is completely enclosed by dense anhydrite below and impervious sediments above, which effectively form a closed reservoir. The depth of the Grand Isle orebody ranges from 1800 ft to 2500 ft below sea level. Within the present boundary, the sulfur-bearing limestone varies in thickness from 220 ft to 425 ft, while the sulfur content varies an average of about 15 pct in the leanest hole to an average of about 30 pct in the richest. Rock containing less than 5 pct sulfur is not classed as ore, and holes assaying less than 20,-000 long tons per acre of sulfur in place are not considered commercial offshore. The sulfur enrich-

Jan 1, 1961

By Bruce D. Hansen

For many years, Newmont has focused on improving its operations. After the merger between Newmont and Santa Fe Pacific Gold, Newmont created synergies of more than $50 million a year in Nevada. This was done primarily through optimal ore movements and consolidation of various functions. During the current period of low gold and copper prices, Newmont has refocused its efforts on efficient operations worldwide. At its mine facilities in Nevada, Newmont has used a combination of several strategies to decrease the costs of operations and to increase profitability. These include computer technology, optimal use of infrastructures, procurement strategies, functional consolidation, enhanced mine planning and several available metallurgical processing options.

Jan 1, 1999

By F. H. Buchella, J. F. Buchanan

The San Manuel copper deposit is located about 45 miles northeast of Tucson. The concentrator, smelter, administration building, and other plant facilities are located about seven miles southeast of the ,nine area at the new town of Sari Manuel as shown on Figure 1 (Sketch).

Jan 1, 1961

By Luis Valdivia

Dado que el objetivo principal de un departamento de Geología de exploraciones es el de estimar recursos minerales en nuevos blancos de exploración identificados a través del análisis e interpretación de información geológica proveniente de diversas fuentes. En ese sentido, el presente texto señala la sistematización de los datos geológicos como el uso de las imágenes satelitales, fotografías aéreas, geofísica, geoquímica, cartografiado geológico, sondajes diamantinos, catastro minero, datos geográficos y políticos, etc. a través de un servidor que integre dichas estructuras lógicas de conocimiento, de manera que todos puedan acceder a ella de manera fácil y dinámica. Asimismo, para los datos de carácter numérico llámense muestras, sondajes, leyes, se utiliza la plataforma Access como gestor de base de datos, mientras que para la información grafica superficial, el software ArcGis.

Sep 24, 2008

By J. P. W. Bennie, A. de Jong, G. M. Denton

Mintek together with Middelburg Steel & Alloys, developed the DC arc furnace process for the production of ferroalloys with the expressed objective of smelting ore fines (<1mm) without the need for agglomeration. In the case of ferrochrome production, the DC arc furnace, being a semi-open bath operation, loses radiant energy directly from the bath to the furnace roof and sidewalls above the melt. This energy loss is reflected in a higher electrical energy usage per ton of alloy than for a submerged-arc operation smelting lumpy ores or sintered pellets. The difference increases still further when pre-heated sintered pellet feed is used in a submerged-arc operation. This shortcoming of the DC arc furnace can however be overcome by preheating the feed to the furnace in a fluidized bed or flash reactor fuelled by cold furnace off-gas. In addition to fluidization and preheating testwork, various preheating flowsheets with associated mass and energy balances have been developed and compared from a techno-economic viewpoint. The three major advantages identified were: a) fluidized beds can preheat ores and fluxes up to 950°C without sticking and defluidizing, b) the open bath DC arc furnace does not require expensive coke or char to maintain the burden porosity and, c) the capital cost associated with the milling, pelletising and sintering plant falls away since ore fines are used directly.

Jan 1, 2004

By Joseph Gersic

MINFO has been developed to serve as a frontend for three databases created to store basic minerals information gathered during the minerals resource assessment conducted by U.S. Bureau of Mines(USBM) for the Malheur and Jordan resource areas of southeastern Oregon(MJRA). The primary database is the Minerals Location Inventory (MLI.DBF) which contains of information assembled from field work performed during this project, the USBM Minerals Availability System/Mineral Information Location System(MAS/MILS) database, the Oregon Department of Geology and Mineral lndustries(DOGAMT) Mineral Information Location(MILOC) database, and the U.S. (Geological Survey(USGS) Mineral Resource Database System(MRDS), In addition, assay results are contained in the geochemical database (ELEMENTS.DBF) and modified X-ray diffraction analysis information is contained in the minerals database (MINOR.M.DBF). MINFO includes four types of program modules: ? Enter/Edit Data was developed to allow the addition of new information and to encourage correction of errors by providing a convenient means of entering and editing data and a large degree of automatic checking and filtering of entries. ? ACAD/DBF Link links each site symbol posted on the map in the drawing file to a record in the database. This provides the user with the ability to use a mouse or other pointing device to graphically select a site for viewing and editing. Edits are performed directly in the database file, ? Reports contains 7 formats of data output for creating files for printing, transfer to other database formats, and exporting to other software packages such as spreadsheets and word processing programs. ? Maps includes 5 programs for creating AutoCAD script files which can be used to create maps of selected information in conjunction with AutoCAD. Mineral location mapping files derived from MLI.DBF can be created in 2 formats. Mapping files can be generated from each of the 2 sets of geochemical analyses contained in ELEMENTS.DBF. X-ray diffraction analyses can also be translated into instructions for creating and posting piecharts at sampling sites.

Jan 1, 1994

By L. F. Contreras

In open pit mine design, it is customary for geotechnical engineers to define the appropriate slope design angles within practical limits. The conventional approach to slope angle design is based on the comparison of calculated stability indicators, such as the factor of safety (FS) and the probability of failure (PF), with generic acceptability criteria not directly related to the impacts of failure. A major drawback of this type of approach is related to the difficulty of defining meaningful acceptability criteria. An alternative methodology of pit slope design is proposed, where the economic impacts of potential slope failures are calculated and used as the elements on which to apply the acceptability criteria for design. The methodology is based on the construction of a graph, referred to as a risk map, that relates the probability of exceeding the economic impact of slope failure to the magnitude of the impact measured in monetary terms. The process includes the analysis of a selected number of representative years of the mine plan and slope sections of the pit areas to define the required inputs for the construction of the risk map. The paper discusses the concepts used in interpreting the probability of slope failure, and describes the approach followed for the estimation of the economic impacts of slope failure and the construction of the risk map. Finally, the two main uses of the risk map are discussed, including the comparison with acceptability criteria for the evaluation of a specific open pit design and the comparative analysis of open pit design options in terms of value and risk to identify optimum pit layouts.

Jan 1, 2015