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By Robert B. Parsons

"The Canadian mining industry is not off to a good start in the 1993/94 budget season. Of the five provinces and territories to table budgets as of March 31, 1993, the industry's scorecard shows: one win, one tie, and three losses.IntroductionBy the end of March, five of Canada's twelve provincial and territorial governments had tabled their 1993/94 budgets. The mining industry is off to a bad start. The industry's scorecard shows one win, one tie, and three losses. Only Newfoundland appears to be paying any attention to the industry's concerns about the impact of taxation on competitiveness. It is particularly disconcerting to see that non-profit based taxes continue to increase, at a time when these taxes are the focus of a united attack by the entire industry.NewfoundlandFirst, the good news. On March 18, 1993, Finance Minister Winston Baker announced the following changes to the province's mining tax regime:"

Jan 1, 1993

By Brad Simser

The Brunswick No. 12 Mine is a 10 000 tonne per day producer of lead-zinc-copper-silver ore that has been in operation since 1964. Mining of this multiple lens deposit is primarily by blasthole stoping techniques between 400m and 1200m below surface. The combination of a high overall extraction ratio and high horizontal stresses (twice the vertical) has elevated the induced stress regime to levels comparable to much deeper operations. Improved mine design, and a better understanding of how the rock mass responds to mining in high stress environments is essential to improve overall recoveries and maintain safety. Seismic monitoring has proven to be an essential tool at Brunswick, for both short-term safety of workers, and long-term strategic planning. Practical case studies illustrate how seismic data, particularly source parameter information, can be used to measure the rockmass response to mining and improve mining layouts in difficult regions. As the global trend continues towards mining in deeper, higher stress environments (e.g. South African Witswatersrand Basin, Sudbury Basin) and as local extraction and thus ground stresses continue to increase in existing deposits, seismic monitoring will play a critical role in mining safely and economically.

May 1, 2003

By V. Eu. Anufriev

Despite of significant cost advantages and the positive expierence roof bolting is limited up to 15-20% of all workings at the Cuzbass mines. The low level of application of the technology is the result of specific mining and geological conditions and defects of organization and technical support. When analysing mining and geological conditions of development working maintenance and geomechanical aspects the necessity of changing of technological schemes of preparation and extraction of mine sections is obvious. The prospects of large-scaled transferring from frame support to roof bolting are connected with introduction the technology of support with the help of non- expanding bolt classes including bolts with mineral filler fixation. The design of bolters with mineral filler fixation is given here. The results of testing of bolt load characteristics in artificial holes and in situ are proved the technology efficient. For increasing of drilling works efficiency it is necessary to master the production of oilless compressor and heading machines with the manipulator. For bolt dimension forecast it is recommended to use the relations of measured parameters of "dome" to roof shifts. Effective monitoring of rock pressure in the junctions is connected with the use of support of conventional bolts together with bolts of deep installation with simultaneous supporting of face ends with special mechanical sets, which compensate face length change.

Jan 1, 1996

By Naresh Koirala

The Greater Vancouver Regional District completed installation of a 2.5 Km long, 2400 mm diameter concrete sewer in Delta, British Columbia in 2000. The sewer traverses through area of peat and soft ground. The ground investigation along the sewer alignment consisted of cone penetration tests and auger drilling with standard penetration tests. The gravity sewer is supported on precast, pretensioned spun concrete piles imported from Malaysia which had never been used for a major project in North America. The capacities of the installed piles were tested using pile driving analyzer (PDA) and three static load tests. A total of 46 PDA tests were carried out during pile installation. The paper describes the pile vetting process the owner went through prior to accepting the piles for use in the project and performance of the piles. It compares the pile capacity estimated from the PDA tests with that estimated from soil mechanics methods using data from cone penetration tests and standard penetration tests. The ranges of estimated capacities calculated by different methods are discussed from design capacity selection considerations.

Jan 1, 2004

By John Rusnak, Christopher Mark

Point load testing is used to determine rock strength indexes in geotechnical practice. The point load test apparatus and procedure enables economical testing of core or lump rock samples in either a field or laboratory setting. In order to estimate uniaxial compressive strength, index-to-strength conversion factors are used. These factors have been proposed by various researchers and are dependent upon rock type. This study involved the extensive load frame and point load testing of coal measure rocks in six states. More than 10,000individual test results, from 908 distinct rock units, were used in the study. Rock lithologies were classified into general categories and conversion factors were determined for each category. This allows for intact rock strength data to be made available through point load testing for numerical geotechnical analysis and empirical rock mass classification systems such as the Coal Mine Roof Rating (CMRR).

Selective Removal of Arsenic from Acid Mine Drainage Containing Ferrous Ion Using Sulfide Precipitation Method

Sep 13, 2010

By Teale E. O

The purpose of the present communication is to put on record the discovery, in October, 1916, in the Howqua district, of a new locality for the occurrence of phosphatic rocks in Victoria, and to give a preliminary description of its characters and geological occurrence. Owing to the great use of superphosphates for agricultural purposes in recent years in Australia, search has been stimulated for the discovery of local and workable supplies of phosphatic rocks. Phosphorus is an element very widely distributed in igneous rocks, usually in the form of the mineral apatite, and also occurs in sedimentary rocks and in soils as a detrital constituent. Under these conditions of occurrence, however, the amount of P 205 present in a rock or soil seldom approaches, and very rarely exceeds, 1 %. Very occasionally it occurs in such a concentrated form as to constitute workable deposits. In such cases they are usually of organic origin. Sometimes they occur as geologically recent deposits of guano or rock...

Jan 1, 1918

By George L. Gates

[When clays e.re mixe~ "Jith "~later to nake mud fluids f'ol' use in :irilling ','Iells "for oil and gar: h;:r vue :;'0 tary me thee. t 18 liquid mij~ tUl"es have certair.. phypicr..l characteri.",t.ics that vary ",dth t e Qlldlltit.y find]

Jan 1, 1941

By C. M. F. Vieira

In the county of Campos dos Goytacazes, north of the State of Rio de Janeiro, Brazil, there is a large production of red ceramic, mainly perforated bricks. A percentage of these bricks are damaged during the firing processing and become a red ceramic waste. This work investigates a possible solution to this environmental problem through the mixture of fired brick wastes, up to 20 wt.%, with clay bodies to produce red ceramics. Cylindrical pressed bodies were fired at temperatures varying from 500 to 1100ºC. After firing, samples were then tested for linear shrinkage, water absorption and mechanical strength. The results showed that brick waste addition did not changed the workability of the clay and that up to 5 wt.% of waste no detrimental effect occurred on the fired properties at all temperatures.

Jan 1, 2010

By Mario Teruo Enju

Soluções flexíveis, com baixo custo de implantação e manutenção, de sistemas de controle de processos e informação utilizando tecnologias de ponta desenvolvidas em plataforma .Net Framework. Focadas inicialmente em área Metalúrgica, onde eficiência em custos e alta confiabilidade tem relevância fundamental para sua viabilização econômica, estas soluções podem também ser aplicadas em áreas Siderúrgica, Petroquímica e demais segmentos. Integração das informações do chão de fábrica com o sistema de gestão da empresa com objetivo de facilitar a tomada de decisões estratégicas. Banco de dados relacional é o principal repositório de dados para compartilhar informações com a rede corporativa, gerenciado por uma ferramenta de software em tempo real para as lógicas de negócios e camada de apresentação. Maior performance, facilidade de operação, disponibilidade de dados, OEE, manutenção simplificada, acesso e ações remotas são viabilizados, permitindo menor custo e maior eficiência.

Jul 30, 2018

By A D. Caccioppoli

Grade control systems within Rio Tinto Iron Ore have proven to be robust, when mining full benches. The Hope Downs 1 operation hosting two Marra Mamba Iron Formation deposits (North and South Deposits) presents a new challenge, where increased mining selectivity due to moderately plunging N-verging folds has made flitch mining necessary in the South Deposit. Poor flitch blasthole sample duplicate results in South Deposit over a 12 month period, compared to North Deposit, have highlighted concerns with grade predictions. In contrast a new grade control methodology (grade splitting) was proposed to alleviate blasthole sampling bias, utilising geological mapping and mineralogical logging, currently practised throughout Rio Tinto Iron Ore Pilbara operations, to estimate theoretical grades for each flitch from a single blast cone assay. To assess this method, reverse circulation holes (RC) were twinned to blastholes establishing an ‘actual’ grade. These blastholes were assayed using current flitch sampling techniques where: flitch positions were estimated, flitch positions were marked with paint, and a full cone sample was taken for ‘grade splitting’. Using these data sets multiple grade predictions were produced, then analysed using Half Absolute Relative Difference (HARD) statistical analysis. In addition to testing these grade control methodologies two other findings were ascertained: an inherent bias in blasthole assays exists particularly in the top flitch, where an average absolute difference of 0.6 per cent in SiO2 and 0.42 per cent Al2O3 was measured; and assays derived where kaolin rich soft shales are intersected were less representative. This is likely to be due to these materials not being properly represented in blast cones. Grade splitting accurately estimated block chemistry, except for a slight under-prediction in Al2O3 and P compared to current grade control methodologies. This method is a viable alternative where grade distribution is stratigraphically controlled.

Aug 22, 2011

By L. Villa, O. Suarez, D. Arias, L. G. Corretge

The deposit comprises two vertical, lenticular bodies emplaced in the allochthonous block of a Variscan thrust. Epigenetic mineralisation occurs as replacement of carbonated volcaniclastic rocks of Cambro-Ordovician age. The dominant sulphide minerals are sphalerite and galena with minor chalcopyrite; the main non-metallic mineral is quartz and there is hydrothermal silicification, chloritisation and sericitisation. Sulphur isotope values for sphalerite and galena are heavy and reflect the fundamental relationship between delta-34S in ZnS and in PbS, suggesting isotopic equilibrium. Four sphalerite-galena pairs yield temperatures between 163 and 218 degrees C, in good agreement with the 187-207 degrees C estimated by the Ga/Ge-sphalerite geothermometer. The ore sulphide was leached by the hydrothermal solution from diagenetic pyrite in the host rocks and disseminated sphalerite and galena in Cambrian carbonates

Jun 19, 1905

By John P. Shubilla1, Nicholas Kyriazi

A joint effort by the Pittsburgh Research Center (PRC) and the Mine Safety and Health Administration (MSHA)3was undertaken to determine how well self-contained self-rescuers (SCSR's), deployed in accordance with Federal regulations (30 CFR 75.1714), held up in the underground environment with regard to both physical damage and aging. This report presents findings regarding laboratory-tested SCSR's in the fifth phase of testing from mid-1993to early 1996. The SCSR's were tested on human subjects and on a breathing and metabolic simulator (BMS) at PRC. These results indicate that most of the apparatus, if they pass their inspection criteria, perform satisfactorily.

Jan 4, 1996

By J. Cygankiewicz

Efficient prevention of mine fires is impossible without predicting the self heating processes in the given geological and mining conditions. The respective forecasting method is presented in this paper based on the following assumptions: - factor deciding on fire hazard in the underground workings is the process of heating of coal from the primary rock temperature to the critical temperature when the heating rate growth rapidly - another important factor is the fire incubation time defined as time needed to achieve the critical temperature. This time is determined by balance of heat and mass in the heated coal - contact of crushed coal with oxygen in air cause some exothermic processes as : physical and chemical sorption of oxygen , oxidation reaction and evaporation of humidity Heated coal transfers its thermal energy to the environment by conductivity to the rocks and by convection to the flowing gases. The heating is possible if thermal energy generated from coal is greater then the share transferred to the environment. The paper presents the laboratory method of measurement of heat generation in adiabatic conditions. Also the mathematical model with examples of computation enabling to forecast the self heating process of crushed coal is presented.

Jan 1, 2003

By Staff

"INTRODUCTION Sheet mica is one of the most important minerals in modern industry. It is used in many kinds of electrical devices, and up to the present time no satisfactory substitute for it has been developed. It is necessary for the successful operation of airplanes, ships, motor vehicles radios, and radar equipment. Early in World y r II, the Array and Navy, foreseeing the need for conserving the stock of sheet mica on hand and realizing that imports from India and Brazil were falling off, had strategic mica placed on the critical war-materials list.Examination and exploration by the Bureau of nines indicated that there probably are large undeveloped deposits of mica in Alabama, some of which are near the surface and others at greater depth. The quality of most of this mica is high.During World War I, Alabama mica producers added materially to domestic production, but after 1920 virtually all of the mines closed end miners scattered. During World War II, when imports from India, Madagascar,Brazil,,other foreign sources were reduced, sometime was required for Alabama to act into production. Operators began to produce small quantities in 1942.The Colonial Mica Corporation was created by the Government during 1942 to buy Mica for the Metals Reserve Company, end later Colonial was made sole buying accent for strategic mica. About this time the Bureau of Mines estab¬lished the graphite field laboratory at Ashland, Ala. Samples of mica wore submitted for examination, and advice was requested by property owners and mine operators. This continued during 1943, when as many as 400 visitors a month called at the Bureau's Ashland field laboratory."

Aug 1, 1946

Minerals contribute to the U.S. gross domestic prod-uct (GDP) at several levels?mining, processing and manufacturing finished products. In 2008, the estimated growth rate for the real GDP of the United States was 1.1 percent and the nominal GDP was about $14.3 trillion (Table 1). Trends in various sectors of the domestic economy are often reflected in mineral production and consumption rates. For instance, continued declines in the U.S. housing market during 2008 were reflected in further reductions in the production and consumption of cement, clays, construction sand and gravel and crushed stone (mineral commodities that are used almost exclusively in construction), and those associated with the related manufacture of goods, such as ceramic tile, heating and air conditioning equipment, paint, plumbing and sanitaryware, roofing, wiring and wallboard ? all used by the housing industry. The widespread effects of the slowing domestic economy became more apparent in the last three to six months of 2008 when prices for many mineral commodities declined sharply after reaching record highs earlier in the year, indicating significantly lower demand for those materials or products containing them.

Jan 1, 2009

By S. Caron, P. Radziszewski

Industrial practice in mineral processing shows that an important problem in understanding and monitoring in-mill parameters is due to the lack of fundamental knowledge and appropriate sensors. However, over the last decade, Discrete Element Method (DEM) modelling has shown an interesting potential in describing the fundamentals of grinding mill behaviour, in improving the understanding of internal grinding mill dynamics, and in developing solutions to industrial practice. With the objective of bringing this modelling technology into the concentrator control room to assist operators, this paper aims to describe the main elements needed to apply this emerging and developing technology to on-line mill performance monitoring.

Jan 1, 2004

By Alex Chapman, Cam Thomas, Bryan Karney

"During the early summer of 1989, Ontario Hydro removed a concrete portion of the North Channel Dam at Crystal Falls Generating Station by blasting and excavating in marine conditions. Because of the severity of underwater blasting and because the site was in close proximity to the replacement dam, there was concern that hydraulic shock waves generated by the detonation could damage either the new dam or its control structures. This paper examines the data associated with the hydraulic shock waves generated by underwater blasting, and studies the effectiveness of an air curtain in reducing the peak pressures. In previous trials using the air curtain technique, a rule-of-thumb factor was used to estimate that only 10% of the original pressure pulse would propagate across the air curtain. However, this value had little basis in theory. A theoretical formulation of the problem by Karney in 1989 indicated a provisional value of 0.18 for this factor, but was heavily dependent on confirmation from in-field testing. Data provided by Ontario Hydro from an actual blasting procedure indicate that a more conservative value of 0.32 may be more appropriate. Thus.although the air curtain did provide considerable reduction of peak pressures, the data at Crystal Falls indicates its performance was below the anticipated level. However, due to problems with the instrumentation and some inconsistencies in the resulting data. it is recommended that this value be further refined as additional data become available."

Jan 1, 1992

By R. G. Shen

The relation curve of strain and acceleration is presented in this paper. The steel pipe pile of 609.6 mm in external diameter driven by IDH-45 diesel motor hammer on the esturial shoal of Yangtze River. The ultimate bearing capacity of pile is analyzed by one dimensional wave equation and the effect of computational parameters of the equation is discussed.

Jan 1, 2010

By C. Laughton

The Deep Underground Science and Engineering Laboratory (DUSEL) is to be constructed at the defunct Homestake Mine, in South Dakota. As a cornerstone of DUSEL?s research program, it is intended to conduct experiments into the fundamental nature of neutrino and proton particles. The experimental apparatus required to con-duct these experiments will be housed in large rock cavern(s) sited at depths of over a kilometer. As conceived, these cavern(s) are planned to have mined volumes of up to half a million cubic meters, and spans of approximately 50 meters. The paper will describe key end-user requirements, and outline the in situ rock conditions and mine site constraints that are likely to play determinant roles in identifying candidate sites and developing cost-effective design options(s).