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By R. C. Earlougher

Jan 1, 1970

By L. B. Davidson

The petroleum literature contains many reports on the relative permeability properties of porous media. However, only recently have studies of relative permeability at elevated temperatures been made.1 -5 Each of these studies presents relative permeability data on water-oil systems in linear sandpacks or sandstone cores under isothermal conditions. The results of these investigations are dissimilar. Edmondsonl found that in Berea sandstone a temperature-dependent effect was present, while Shilobod,2 using the same material, found no temperature dependence after normalizing for initial water saturation. Workers at Texas A&M U.3-5 found that the ratio kw/ko was temperature dependent in an unconsolidated system. The differences in results of these studies are probably a consequence of differences in the material employed, in the experimental procedures followed, and in the properties of the porous systems used. This paper describes an experimental investigation of permeability ratio temperature dependence, conducted to clarify some of the results obtained by previous workers. Each experiment described in this paper involved the isothermal displacement of Chevron No. 15 white oil by either nitrogen, steam, or distilled water and displacement of water by nitrogen. All permeability ratios were calculated using the Welge procedure. Values of the water-oil permeability ratio were obtained over the temperature range 75OF to 540°F. Results indicate the ratio is temperature dependent at low water saturations, probably due to interfacial effects. However, as the saturation is increased, temperature dependence decreases until, above some minimum saturation, the ratio becomes insensitive to temperature. Previously published work indicates that the dependence reappears at very high water saturations, a region of the ratio curve not completely examined in the present study. It appears that water-oil permeability ratios are temperature dependent at the extremes of the ratio curve where changes in interfacial tension with temperature induce variations in residual saturations. Between the extremes, there is a region in which the permeability ratio is insensitive to temperature. The size and location of this region is probably a function of the characteristics of the porous system. Gas-oil permeability ratios calculated from nitrogen-white oil displacement experiments indicate a definite temperature dependence over the range 75OF to 500°F and over the entire gas saturation range studied. Evidence discussed in this report indicates that this dependence is a consequence of molecular slippage in the gas phase. This is an extension of the Klinkenberg effect6 to two-phase systems at high temperatures (the existence of slippage in two-phase systems at room temperature has been demonstrated7). Evidence for a similar source of temperature dependence in superheated steam-white oil experiments

Jan 1, 1970

By HASSAN E. EL-SHALL, AYMAN A. EL-MIDANY, KERRI-ANN A. HUE

Modifying the hydrophobicity of clay is necessary to accommodate large mycotoxin molecules such as zearalenone (ZEN). In this study, tricaprylmethylammonium (TCMA) chloride and common corn oil were used to modify clay. The results indicate that more than 90 percent of ZEN could be removed using clays modified by TCMA and corn oil at acidic and neutral pH due to the expansion of intergallery spacing as a result of TCMA surfactant intercalation within the clay-forming layers. The removal percentage depends on the pH and amount of clay used. Complete removal can be achieved at acidic pH and small clay amount.

The Effect of Ionic Strength of Plant Water on Valuable Mineral and Gangue Recovery in a Platinum Bearing Ore from the Merensky Reef

Sep 13, 2010

By Carrie Smith

In a major milestone for geoscience, the U.S. Geological Survey (USGS) has unveiled the Cooperative National Geologic Map, the most detailed national-scale geologic map of the country to date. The project offers a fresh, layered look at the rocks and sediments that make up the United States. For geologists, engineers and mining professionals, it provides both a technical achievement and a practical tool that will help shape future exploration and landuse decisions across the country. The new map provides a regional view of geology both on and beneath the Earth’s surface. Using different colors to represent rock types and sediments, it allows users to toggle through multiple layers, revealing for the first time the surficial and quaternary deposits that lie above the bedrock. “This is the first national map to include multiple layers of mapped geology, the first built to be easily updated as new maps are published, and the first to be delivered in a user-friendly online interface,” said Joseph Colgan, a USGS research geologist who led the development team. The Cooperative National Geologic Map is a culmination of more than a century of collaborative mapping between the USGS and the nation’s state geological surveys. More than 100 existing maps produced by state geological surveys and the USGS over the past 40 to 50 years were combined and standardized to create the national data set. During its three-year creation, the USGS prepared digital data, built the system to bring the maps together, developed the web interface and underwent a review and approval process. Through this process, decades of fieldwork, analysis and digital cartography were brought together to provide both national and local expertise.

Nov 1, 2025

By C J. McKenzie, D F. S Natusch

The lignite deposits of Southland and Central Otago are a potentially significant energy resource for New Zealand. Current estimates put the technically mineable lignite reserves at 5.3 billion tonnes, which is more than ten times the energy content of the Maui gas field. Thus, the strategic importance of the lignite as a basis for maintaining current levels of self-sufficiency in transport fuels, or as a possible feedstock for electricity generation, deserves full investigation. The full extent of the lignite deposits was only recently established as the result of a scout drilling programme undertaken between 1976 and 1979 by the Mines Division of the Ministry of Energy, and from companion studies conducted by the New Zealand Geological Survey. These discoveries of large quantities of lignite coupled, at the time, with rising oil prices, raised the prospect of their development for production of transport fuels.

Jan 1, 1983

By R. L. Taylor, S. D. Abbott

"INTRODUCTION Mines are filled with a mixture of gases, some of which are toxic, flammable, explosive. Others can be early reporters of potential problems. It has previously been shown that analysis by gas chromatograph can the most accurate conventional analytical tool for common mine gas mixtures when used correctly. There are some other detection methods (e.g hand held sensors), but they do not detect many situations which are immediately dangerous to life or health (IDLH). Examples include explosive hydrogen mixtures, toxic carbon dioxide levels, and some explosive mixtures of methane with oxygen. (Reference our previous paper). There are several reasons for mines to consider onsite GC analysis. (1) Timeliness of results. Samples can be taken and analyzed immediately. Samples do not have to be shipped to a lab and wait for results. (2) Ability to run greater number of samples a lower for the same cost. This allows mine to increase the number of samples taken to be more informed about the gases/conditions of the mine without the worry of financial constraints. (3) Fewer sample media needed, and there is no wear and tear or cost from shipping them offsite. When samples are shipped offsite, those sample media cannot be used to take until the lab returns them when the analysis is done onsite, the sample media can be used again almost immediately. However there are several challenges associated with using GC to analyze mine gas samples onsite. To date there has been a clash of the requirements for a successful analysis, the capabilities of the technology, and the practicalities of implementation. The purpose of this paper is to discuss some of the difficulties in getting accurate reliable data and doing so in an economic way. This whole measurement activity is a cost center for a mine, so there are economic concerns for the mine to address. These concerns are mainly staffing costs, capital costs, maintenance, and consumables costs. A properly staffed and equipped analysis lab, including burdened overhead, costs about $500K per year. At a sampling rate of 10 per day, this is about $140 per measurement for a proper onsite lab."

Jan 1, 2016

By James J. Meadows, Jason D. Pampena, Emanuele G. Cauda, Lauren G. Chubb

Exposure to respirable crystalline silica (RCS) can cause serious and irreparable negative health effects, including silicosis and lung cancer. Workers in coal mines have the potential of being exposed to RCS found in dust generated by various mining processes. The silica content of respirable dust in one single mine can vary substantially over both time and location. The current monitoring approach for RCS relies on the use of traditional air sampling followed by laboratory analysis. Results generated using this approach are generally not available for several days to several weeks after sampling, and this delay prevents timely and effective intervention if needed. An alternate analytical method is needed to reduce the time required to quantify the RCS exposure of mine workers. The National Institute for Occupational Safety and Health (NIOSH) has developed a new method using commercially available portable infrared spectrometers for measuring RCS at the end of the sampling shift. This paper will describe the application of the new field-based RCS analytical process for coal mines, including the use of the new method with the existing Coal Mine Dust Personal Sampler Unit. In a case study conducted by NIOSH with a coal mine operator in West Virginia, field-based RCS analysis was completed at a mine site to evaluate the new technique. The RCS analysis results obtained by the field-based method in this case study showed sufficiently strong correlation with results obtained by the MSHA standard laboratory analysis method to allow the mine operator to use the field-based method for evaluating process improvements.

Construction workers may be exposed to hazardous dust containing crystalline silica during site preparation when drilling systems are used. The National Institute for Occupational Safety and Health (NIOSH) found that drill dust could be decreased by using wet or dry dust reduction engineering controls, enclosed cabs, and implementing a dust control program.

Jan 1, 2009

By D. Pillay

Outsourcing? and ?sub-contracting? have become buzzwords in recent years, as SA industry becomes increasingly exposed to the global economy, and global competitiveness. In its effort to ?catch up? after years of relative isolation, there is a concerted effort to learn from global ?best practice?, in order for South African companies, and the SA economy, to become ?winners?. There seems nothing wrong with this approach at face value. Companies need to compete and be profitable if they are to remain in business. Failure will in the end mean bankruptcy, and the loss of jobs. However, if one interrogates the precise practices, and their implications for all concerned?not just shareholders and employers, but workers, communities, the environment, future generations, the national economy?then the picture can change dramatically. ?Best practice? for whom?

Jan 1, 1999

By Takashi Ikeda, Masafumi Maeda

"Demand for solar cells is increasing linearly throughout the world. Last year production totaled 3000 tons worldwide. The market size of solar silicon is expected to increase further because of international ""political"" demand to reduce carbonaceous emission from energy consumed. Most elemental silicon is produced by the carbon reduction of Silica in an electric arc furnace. Purity of silicon at this stage is 90-99%. Major impurities are Fe, Ti, Ca· and Al, and minor ones are P, B and carbon. The oxidizing metallurgical process is no longer effective to remove transitfon metals because those are less noble to silicon. Nonmetallic impurities such as phosphorus and boron must be reduced to 0.001ppm for semiconductor use. The most common process for high purity silicon is the Siemens C process, which is basically distillation of hydro-chlorinated silicon followed by CVD of SiHCl3. The cost of such silicon is expensive to allow its popular use in solar cells. Currently scrap silicon -of semiconductors is used for this; however, the supply-of that scrap is limited to just a portion of semiconductor production.In this paper world demand for silicon will be reviewed and some of the processes proposed summarized.IntroductionSilicon is element 14 in atomic number and has an atomic weight of 28.0855. Little elemental silicon is found in the earth, and it is mostly found as oxides or silicate. The Clark number of silicon is very large and the second in its number. If we were discussing the volatility of silicon element on the globe, we would never worry about it. However, it is very difficult to obtain pure elemental silicon because a high purity silicon compound is very rare. In most cases these are silica (silicon oxide SiO2). As shown in Table 1, there are many grades of silica ore classified mainly by their content of iron and alumina."

Jan 1, 2000

By Schneider, W. G.

IT is not my purpose to burden you with many statistics. The charts herewith should be considered merely as indicating the trend. I believe' that is what is really of interest to us. It is difficult, if not impossible to forecast with any assurance future developments, because of possible new mines, competitive materials, curtailment' or increase in the use of the metal in certain markets, and many other factors that have a vital bearing on any industry. Fig. 1 shows United States smeltet output of copper, starting with 1845. It is estimated that in 1928 the smelter output of copper will be about 1,010,000 tons. Between 1895 and 1905 it increased about 200,000 tons, and between 1905 and 1915 about 240,000 tons. Between 1915 and 1925 the increase was about 140,000 tons. This is an average increase over 30 years of about 190,00Q tons per ten-year period. At the present time the indications are that this demand for increased production will continue. As to whether or not we have the supplies or facilities to maintain this increase or a greater one, remains to be seen. Provided it is possible for United States smelters to increase their production, they should be producing at the rate of about 1,210,000 tons or more per year by 1935.

Jan 1, 1928

By James J. Anderson

In this talk I will report on an effort to reassess the risk of pile driving to juvenile salmonids migrating through Puget Sound. The study was motivated by the concern of the construction industry that provisions restricting pile driving during the spring migration is resulting in an unbalanced burden to the industry. In simple terms the industry wants to know if some construction can be conducted in the spring without harming the juvenile fish. Fisheries agencies have agreed to reconsider their regulations in the context of additional studies. So, in this talk I will present some thoughts on risk assessment in general and the results of our study to assess the impact of pile driving on Snohomish River juvenile pink and chum salmon that migrate through the Navy Homeport construction site at Everett. The research, which is being carried out by the Fisheries Research Institute at the University of Washington, was planned and is supported in a joint effort including: the Washington Department Fisheries, National Marine Fisheries Services, U.S. Fish and Wildlife Service; General, Manson, and Hurlen construction companies, the Department of Transportation and a number of Puget Sound ports authorities. I will first briefly discuss the early life history of the juvenile salmon the regulations are designed to protect Second, I will outline the legal criteria required for risk regulation and some specific thoughts on how a reassessment of pile driving risk might be approached. With this basis I will report on our research and how it can be applied to a new risk assessment.

Jan 1, 1990

By Mir Ahmad Mohammadi

Land uplift due to mine flooding has become a significant challenge with extensive historical mining activities, particularly in Germany’s Ruhr district. The cessation of coal mining operations has led to a gradual rise in groundwater levels, altering geotechnical and hydrological conditions and causing surface uplift. This study develops a system dynamics (SD) model to investigate the dynamic interactions of influential variables such as groundwater levels, total stress, porosity and permeability with land uplift over time. The model integrates causal loop diagrams (CLD) and stock flow diagrams (SFD) to comprehensively understand the system’s behavior. SFD illustrated that for a 10 percent increase in groundwater level, the land uplift increased by about +6 percent, and a rise of 200 percent in total stress caused an 18 percent increase in effective stress, which decreased the land uplift by about 20 percent. This study highlights the importance of dynamic modeling in informing land-use planning and mitigating the long-term impacts of land uplift after mine closures.

Mar 1, 2025

By T. F. Oliveira, E. B. Zanelato, J. Alexandre, L. J. T. Petrucci, A. R. G. Azevedo

The paper and cellulose industry is responsible for generating large amounts of solid waste, which are produced during various stages of the production process. Currently this material goes to places like landfills and other generating costs for the company. Furthermore, cement, mortar and concrete represent a significant economic and environmental cost. This study aims to determine the pozzolanic activity index in the residue studied to verify its viability in the incorporation of the same in cement. It will be used Luxan method for this determination. The data found show that the material has the possibility of being incorporated in the mortar due to its pozzolanic activity index.

Mar 1, 2017

By Carlos Maurício F. Vieira, Gabriel Oliveira Glória, Maycon Sidney Gomes de Camargo, Sergio Neves Monteiro, Fábio da Costa Garcia Filho, Maria Carolina Andrade Teixeira, Frederico M. Margem

The society is increasingly the concern about the ambiental impacts, and demand for eco-friendly materials. The composites reinforced with synthetic fibers are been replaced by composites reinforced with natural fibers because of the environmental advantages. Besides the environmental advantages, those fibers have economical and properties advantages, like the low density and cost. Composites with up to 30%of PALF fibers were tested. The analyzed parameters were the loss modulus, the storage modulus and the delta tangent. The test was conducted in the temperature interval from 25 to 195 °C in a DMA equipment operating at 1 Hz of frequency under a nitrogen flow. The results showed that the incorporation of continuous and aligned PALF fibers tends to increase the viscoelastic stiffness of the epoxy matrix. Contrasting this, minor changes occurred in both the glass transition temperature and the damping capacity of the structure as measured by the tan delta peaks.

Mar 1, 2018

By S. J. Cook

The system of mining statistics for Canada, as it exists today, represents the result of long years of progress, first by the Geological Survey, later and more comprehensively by the Mines Branch of the Department of Mines, and now by the Mining Branch of the Dominion Bureau of Statistics-all supplemented by the very comprehensive reports published by the several provincial departments of mines. It is the purpose of this paper briefly to state the development and present status of Canada's statistical service, more particularly in regard to information on mineral production, and to show that in its evolution continuous progress has been made in the elimination of factors tending to duplication and overlaping, with the result that the construction of an adequate statistical service has been carried out with the least possible expenditure of .public funds. For the purpose of this discussion, the subject of mineral statistics may conveniently be considered from two points of view. The technical difficulties in obtaining satisfactory and complete data from the variety of industries represented in the mining fields of Canada must be apparent to all. Methods of record-keeping are almost as numerous as mines and even the larger concerns which maintain elaborate records for their own information, often find it difficult to compile the statistical reports required of them, because the specific form of inquiry differs from the method in use in their offices.

Jan 1, 1924

By C. Sunderman, J. Johnson, S. Signer

Researchers at the National Institute for Occupational Safety and Health have developed a miniature data acquisition system (MIDAS) that can measure resistance changes and temperature, store data for later retrieval, and illuminate LED lights. This instrument can be used with strain-gaged bolts, cable bolts, CSIRO stress-measuring gages, string pots, and any other instrument that uses single-ended, resistance-type gages. MIDAS has the capability to measure up to 16 gages at preset time intervals and store more than 2000 scans, yet is small enough to fit in a 35-mm hole. Because the MIDAS consumes little power, a 9-V alkaline battery will operate the system for 6 months. Data from the MIDAS can be sent to a PC via an RS232/RS485/IRdA port. A software program was written to set operation parameters, graph data, and store all information directly to a spreadsheet. Three LED lights change from green to yellow then red based on reading levels and/or rates of change. This feature can be used with different types of gages to warn miners of possible rock instabilities. The MIDAS has received MSHA experimental permissibility approval and is currently being tested at several mines.

By S Nowosad, A Binder, O Langefeld, M Bothe-Fiekert, F Apollo

The mining industry faces complex and urgent challenges driven by an increasing demand for raw materials, and a socially demanding globalised world. The extraction of primary raw materials is today more important than ever as one of the cornerstones towards a sustainable future since the increasing demand for the raw materials required for the energy transition. In the last three years, leading countries as USA, China, Canada, Australia, and the European Union (EU) have developed and adopted strategies to enhance domestic extraction capabilities, diversifying sources, fostering innovation in recycling, and promoting international collaboration related to critical raw materials. On 2022, the Inflation Reduction Act was signed into law in the USA, in June 2023, the Australian Critical Minerals Strategy 2023–2030 was published and in March 2024, the Council of the EU adopted the European Critical Raw Materials Act. On the other hand, raw materials extraction is facing higher environmental and safety standards and regulations, as well as scrutiny from the broader public. Regrettable environmental accidents as tailing dam failures or acid mine drainage occurrences have led to a general distrust of mining activities leaving mining companies with the dual imperative of increasing output while implementing sustainability, decarbonisation, and circularity as a core value in their production processes. This challenging environment offers the opportunity to enhance ‘blue mining’ (BM) as a sustainable holistic approach that integrates the principles needed to plan sustainable, reliable, and responsible mines for today’s and future generations by implementing the principles of circular economy (CE). This requires a fundamental shift from the traditional linear economy approach to a sustainable, circular economy strategy. At its essence, BM encapsulates four crucial aspects – energy, ergonomics, water, and circularity and integrates these four aspects into integrative mine planning, defining clear goals and objectives from the ‘blueprint’ of a mine towards a beneficial post-mining activity. Its implementation can lead to maximisation of resources beyond the life of the extractive mine and sustainable use of materials by integrating the principles of circular economy and multiuse mine, see Figure 1. These concepts complement and recognise the need to minimise environmental and social impacts while advancing economic development. Finally, this contribution explains the requirements and challenges of moving from linear to dynamic planning approaches under the BM concept. This way, BM stands as an approach that can contribute to the mining industry receiving necessary approvals and support from society leading to a long-term transformation of the industry’s image.

Sep 1, 2024

By Ashley Haslett

A European Directive on Identification & Traceability of explosives came into effect on the 4th of April 2008. This directive is intended to establish a harmonised system for the unique identification and traceability of all packaged explosives, detonators, reels of detonating cord and primers used in civil applications across the European Union. The directive must be adopted into the national legislation of each European Union member state by the 5th of April 2009 with compliance achieved throughout Europe by the 5th of April 2012. The requirements of the Directive apply to all explosives manufactured, used and imported into the European Union from 5th April 2012.

Jan 1, 2010