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By J. D. Miller, R. J. Smith

Earl C. Herkenhoff Publication of the article "The Flotation Behavior of Digested Asphalt Ridge Tar Sands" by R.J. Smith and J.D. Miller has confirmed and again spotlighted a most significant and important development in the field of tar sand and heavy oil mining. This is the ability to recover 95 % of the bitumen in dry tar sands by a hot water process. The initial investigation by Miller and Sepulveda in early 1978, "Separation of Bitumen from Dry Tar Sands," was the first blockbuter. It is disappointing that there has been so little scientific and industry ackowledgement that the authors laid to rest the long entrenched belief that the sand grains had to be "water wetted" for a hot water process to be applicable. Dr. Miller and his researchers at the University of Utah used slightly different mineral dressing terminology in describing their process but it is essentially the old, established technique of high solids attrition scrubbing at elevated temperatures with a conditioner or modifier, followed by dilution and froth flotation. Similar techniques were described in detail for other nonmetallic minerals in the mid-1940s by Stuart Falconer of American Cyanamid Co. The authors used a 15-minute "scrub" period (or in their terminology "digester step") at 73% solids and 95°C (203°F) in a 0.3 m solution of sodium carbonate -about 4 kg/t (8 lb per st) of tar sand. Flotation was at 10% solids. Obviously, the scrub is an expensive step with respect to energy input but the high recovery of bitumen appears to justify it. Two basic questions then arise: • What are the effects of shorter scrubbing time, lower temperature, and less sodium carbonate? • Would a two-stage approach be advantageous? That is, could you get the major proportion of the bitumen with a mild scrub and apply the high power and temperature only to the refractory portion? These variables should be evaluated. Apparently, all results were only for rougher flotation. What would the grade and recovery of bitumen be if multiple cleaner flotation steps were employed? We must concede that a 60-62% grade of bitumen leaves considerable room for upgrading. Finally, it should be noted by all executives who approve funds for heavy oil recovery schemes, most of which are variations of in-situ methods, that mining can yield a 95% recovery of bitumen. That is correct, 95%. Imagine what that does to the total barrels recovered from a heavy oil resource compared with the scrawny 30-35% maximum recovery we are getting now. The conclusion-let's mine heavy oil and tar sands. Reply by R.J. Smith and J.D. Miller We, too, share Mr. Herkenhoff s enthusiasm for the mining of tar sands-heavy oil and continue the development of related processing technology. Specifically, it will be noted that by appropriate control of bitumen viscosity in the feed (probably the most important variable for successful separation) the recovery can be accomplished at low digestion temperature and low addition of alkali. A 91 t/d (100 stpd) pilot plant based on our technology is now being operated by Enercor in Salt Lake City (Hatfield, Oblad, and Miller, 1982). In these same pilot facilities, rougher concentrates containing more than 80% bitumen on a dry basis are being produced from Asphalt Ridge Feed. However, the processing of certain other tar sands results in incomplete digestion of bitumen/sand aggregates as discussed elsewhere (Miller and Misra, 1982). Such undigested aggregates are shown in Fig. 1. In this regard, it is intended that a recycle stream will be installed in the pilot plant to provide for redigestion of middling products. Further details regarding surface chemistry aspects of this tar sand technology have recently been published (Misra, Aguilar, and Miller, 1981). References Hatfield, K.E., Oblad, A.G., and Miller, J.D., 1982, "Pilot Plant Recovery of Bitumen from Oil Wet Tar Sands," Processing, Second International Conference on Heavy Crude and Tar Sands, Caracas, Venezuela, Feb. 7-17. Hatfield, K.E., Oblad, A.G., and Miller, J.D., 1982, "Pilot Plant Processing of Oil-Wet Tar Sands," Symposium, Rocky Mountain Fuel Society, Salt Lake City, Utah, Feb. 18-19. Miller, J.D. and Misra, M. 1982, "Hot Water Process Development for Utah Tar Sands," Fuel Processing Technology, Vol. 6, No. 1, April, pp. 27-49. Misra, M., Aguilar, R., and Miller, J.D., 1981, "Surface Chemistry Features in the Hot Water Processing of Utah Tar Sand, Proceedings, "Symposium of Separation Science and Technology for Energy Applications," Gatlinburg, Tennessee, May 5-8.

Jan 11, 1982

By Laura Suarez, Jörgen Kajberg, Pär Jonsén

How does an investigation into the breakage characterization of electric arc furnace (EAF) manganese slags contribute to a more responsible usage of resources throughout the life cycle of steel products and reduction of carbon emissions? The main goal of this study is to increase the knowledge on the mechanical response of manganese slag to open the potential of pyrometallurgical residues to become secondary material in industrial applications such as infrastructure construction, fillers, binders and soil stabilization, among others.

Mar 1, 2024

By David Cronan

"Most of the recent renewed interest in manganese nodule mining has been focused in the Clarion-Clipperton Zone (CCZ) in the NE tropical Pacific where nodules are rich in Mn, Ni and Cu. However, equally interesting, but compositionally different, nodules occur in the tropical central South Pacific (CSP). The CC Zone deposits lie in the International Seabed Area whereas those in the South Pacific lie mainly in the Exclusive Economic Zones of Island States, principally the Cook Islands and Kiribati. The CSP nodules should not be regarded as an alternative resource to CCZ nodules, as they are enriched in different elements. Rather, the CCZ nodules should be thought of as a source of one group of metals (Mn, Ni and Cu) and the CSP nodules the source of another group (see below), mutually complementing each other and to be mined in parallel for their different metals.Manganese nodule mining in the South Pacific has been mooted since the 1970s. However, new data on manganese nodule composition and abundance there have recently appeared. Also, a recently developed interest in 'rare', 'green' and 'technology' elements has necessitated a re-examination of old South Pacific nodule data for information on these elements (previously thought to be economically unimportant), and the re-analysis of the deposits to obtain new data on them. Additionally, current and possibly future applications to the UN to extend island 'continental shelf' areas necessitates an appraisal of the manganese nodules in these areas. These developments have prompted recent work that has helped to refine our understanding of the distribution and abundance of metals of traditional interest in South Pacific nodules, namely Mn, Co, Ni and Cu, but has also drawn attention to other elements of possible economic interest including titanium (Ti), vanadium (V) and the rare earth elements (REE)."

Sep 1, 2014

By J. S. Bays

Industries are challenged to meet increasingly stringent regulations for selenium and metals. Cost-effective treatment is required to minimize the economic impact of environmental compliance. Low-cost biological treatment of selenium can be achieved passively using biochemical reactor cells composed of natural organic media components such as wood chips, sawdust, hay, composted manure, and peat. The reactor cells create an anaerobic microenvironment for biological reduction and sequestration of selenium and other metals. Biochemical reactors can be combined with constructed wetlands for flow equalization and to remove the organic byproducts in reactor cell outflow. Passive treatment reduces capital cost and operational effort compared to more expensive and complex physical and chemical treatment. Recent pilot and full-scale projects by mining companies and by the US Bureau of Reclamation demonstrate that passive treatment can achieve compliance with selenium concentrations over a range of flows and environmental conditions. Case histories of passive selenium treatment systems and their key findings are provided, and prospects for future applications are summarized.

Feb 27, 2013

By Ian McFeat-Smith

Despite a present, short-term economic recession, a remarkable enthusiasm exists in Hong Kong for building infrastructure including major tunnel projects. This paper provides details of current and recent bored tunnel works together with an insight into the impressive list of future underground projects planned by the MTRC,KCRC, Highways Department and Drainage Services Department for the next decade. Risks for each of these works including pipejacking, mixed face and rock tunnelling generally in Hong Kong are also identified. From this is evident that the scale and difficulty of such works continues to increase, requiring the use of more sophisticated methods of construction, the need for better methods of assessing and managing risks and for Government to utilize improved, more equitable Conditions of Contract for such major tunnelling projects.

Jan 1, 2001

Invensys’ recently introduced Field Device Manager for Foxboro I/A Series distributed control systems provides the industry’s first solution that takes advantage of both the latest Enhanced Electronic Device Description Language (Enhanced EDDL) and FDT technologies. This combination provides comprehensive lifecycle support to configure, calibrate, commission, diagnose and optimize the performance of any vendors’ foundation fieldbus device. The I/A Series Field Device Manager enables users to take advantage of any EDDL, Enhanced EDDL and/or FDT host deliverables supplied by the device vendor.

Jan 1, 2007

By R. Elias

Botswana is a mining-dominated sub-Saharan country. Workforces are characterised by poorly educated operators and front line supervisors, with equipment and management to 1st World standards. Poor communication, ignorance of business objectives, inability to meet targets, and lack of problem-solving capacity are the norm. Training leads to high expectations and is of concern to management as a source of dissatisfaction, despite the long-term benefits higher skills have for mine viability. The aims of a technical training programme are presented with various models and approaches being implemented at operations in Botswana. These are used to construct a series of guidelines for technical training initiatives.

Jan 1, 2000

By M. S. Riyazulla

A model of a new laboratory magnetic separator has been conceived to cater the needs of process engineers and mineralogists world over engaged in mineral characterization and beneficiation. It would be essentially a laboratory instrument for the separation and concentration of various ferro and non-magnetic minerals. Based on the basic concept of Frantz Isodynamic Magnetic Separator, the new separator conceived would not only speed up the work of a process mineralogist and save the energy, but it would effectively separate and sequentially produce about fourteen fractions at a time. In the present paper, the probable operational procedures and the design have been discussed in detail for the various mining companies to assess its economic feasibility. If it could be fabricated, it would have a worldwide market The concept has been patented in author?s name in India.

Jan 1, 2009

By H. D. Van Veldhuizen

The Multilateral Investment Guarantee Agency(MIGA) is part of the World Bank Group, and has as its mission the facilitation of foreign direct investment by providing political risk insurance (guarantees) to foreign investors and lenders. As a development institution, MIGA is required to ensure that the projects that it insures will bring development benefits to the host country. Demonstration of this includes review and analysis of the environmental and social soundness of a prospective investment. Environmental guidelines and policies developed by the World Bank Group are important components both in analyzing the environmental and social soundness of a prospective investment and in risk management. MIGA has recently formalized and adopted environmental assessment and disclosure policies. The approach taken by MIGA to environmental review of investments and implementation of these policies is described in this paper.

Jan 1, 2000

By H. C. Liang

Reverse osmosis (RO) and nanofiltration (NF) are widely regarded as being best available technologies (BATs) for removing contaminants of concern from water. In recent years, NF or RO treatment has increasingly gained more acceptance in the mining industry for treating mine water to remove a wide assortment of contaminants, either for meeting discharge standards or for internal re-use in mining processes. Consequently, the number of NF or RO membrane mine water treatment facilities has steadily increased. Although NF or RO membrane filtration can be a powerful tool in mine water treatment, especially when multiple contaminant removal is required, it also has many potential disadvantages. Besides the generally higher capital and operational costs for the high pressure membrane processes, organic constituents in mine water may foul the membranes, while inorganic compounds such as gypsum, calcite, or silica are liable to scale the expensive membranes if proper pre-treatment processes are not implemented. Additionally, because these membrane treatment processes generate a substantial reject or brine waste stream in addition to the clean treated water or permeate stream, brine management also needs to be considered carefully when deciding upon the viability of an NF or RO mine water treatment process. Because of these issues, it is important to conduct detailed analyses of the trade-off between selecting NF or RO vs. using chemical treatment processes when designing a mine water treatment facility.

Jan 1, 2012

By Dan Preston, Shane Yanagisawa, Robert Marshall, Don Deere

Geotechnical Baseline Reports often estimate the number of cobbles that will be encountered in terms of volume or weight. These estimates are practically impossible to verify in the field. ClaroVia Holdings in conjunction with Frontier Kemper Constructors Inc. developed Digital Geologist 2.0 to classify and count cobbles discharged from an EPB TBM at the RSC7 project in Burbank, CA. The system worked by using two stereoscopic laser sensors with a global shutter to scan and count cobbles at 12 frames per second. Results of the effort are revealed along with lessons learned and paths for improvement.

Jun 13, 2023

By T. Geyer

The Carbon Disclosure Project (the pre-eminent global initiative for institutional investor collaboration on climate change) groups the business risks (and opportunities) related to climate change into four categories: 1. Regulatory risks from tightening legislation (and opportunities for companies that can make the carbon market work for them), e.g. rising costs for carbon and energy-intensive processes. 2. Competitive risks & opportunities generated by a possible decline in customer demand for carbon/energy intensive products (and opportunities from a consequent rise in demand for efficient / low carbon products). 3. Reputational risks from perceived inaction on climate change (and benefits to those perceived to be ?solutions providers?). 4. Physical risks from changes to climatic patterns, e.g. asset damage from extreme weather events; project delays; water scarcity; resource risks as certain crops become no longer viable in certain areas and new supply chains become necessary; and potential human and socio-political impacts. All of these are already having repercussions for businesses in certain sectors and geographies. The understanding of specific impacts of climate change is still evolving but it is clear that climate change will have a material impact on the value of many businesses, either directly or indirectly. Many commentators and analysts consider that rising energy costs are likely to represent the most direct and immediate investment risk that climate change and the resulting regulatory responses will create for business in the near term. However, it is already possible to identify numerous examples of competitive and reputational risks and opportunities that are leading to significant value creation or destruction in business: the success of the Toyota Prius; the rush by the UK?s leading supermarket retailers to ?green? their brands; and the surging fortunes of companies involved in the manufacture of renewable energy generation equipment, are all manifestations of this trend. In addition, the potential physical impacts of climate change are also making themselves felt in certain sectors: an example is the Australian wine industry, suffering after an extreme and prolonged period of drought. THE PROJECT This paper describes a project undertaken for a multinational mining company to examine the physical risks from climate change across its international business operations. The study addressed 163 components of the business and included operating sites (mines, smelters, and refineries), key transport routes (road and rail) and port links. The inclusion of the transport networks and ports is extremely important; key transport routes (e.g. a key railway link) may often be impacted (e.g. by flooding) far more than individual sites due to their large geographic exposure and multiple potential failure points. Extreme weather events causing loss of life and major economic damage continue to be front page news. According to the World Meteorological Organization, January to July 2007 ?was marked by record weather extremes in many regions across the world.? Inevitably, the associated phenomena are starting to impact business and investments, not so much as deal breakers, but in changing the parameters of risk management and the approaches required to devise mitigation measures. EXAMPLES OF EXTREME WEATHER EVENTS No one event can be presented as directly attributable evidence of climate change, however climate change projections suggest that the frequency and severity of many extreme weather events can be expected to increase in a warming world. In August 2003, a heat wave struck Europe, with temperatures as high as 42°C (108°F). As summer temperatures in much of northern Europe rarely exceed 30°C (86°F), the area was unprepared for the disaster, and many thousands of deaths occurred. In August 2005, Hurricane Katrina caused catastrophic damage along the Gulf Coast of the United States, forcing the effective abandonment of south-eastern Louisiana (including New Orleans) for up to two months and damaging oil wells that resulted in increased oil prices. Katrina killed over 1,800 people and caused at least $75 billion in damages, making it one of the costliest natural disasters of all time. This was followed in September, by Hurricane Rita which left 119 people dead along the U.S. Gulf Coast, causing $9.4 billion in damage. In January 2006, hundreds of people were killed when Russia, Eastern Europe and Scandinavia experienced the coldest weather for decades. In summer 2007, dramatic floods in the south central region of England, UK left 350,000 people without drinking water and many without electricity. Transport infrastructure was severely disrupted; combined with floods which occurred earlier in the summer in Yorkshire (North England), the damage is estimated to total over £2 billion. ASSESSING RISKS FROM CLIMATE CHANGE To date, only a minority of companies have attempted to quantify the risks from climate change. However, investors are seeking greater disclosure of climate change related risks and opportunities and it is expected companies that can demonstrate they are prepared for climate change will attract higher market valuations. Climate Change Threats A variety of climate change threats were examined for their potential to have a potential measurable impact on the mining company?s business operations. Those considered most significant were included in the study and are shown in Table 1 (see Appendix A). Certain threats can be considered as being cyclical in nature and the future predictions may suggest a change in the frequency and severity of such events (e.g. storms/hurricanes, rainfall, drought). However other threats are associated with a gradual change over time (e.g. loss of glaciers, loss of permafrost, sea level rises). A slightly different approach is needed to address this differing nature of the threats, as described subsequently. Climatic Regions Much of the research and data associated with climate change is collected and reported on a regional basis. An example of the climate change impacts predicted for a number of climatic regions is shown in Table 2 (see Appendix A).

Jan 1, 2009

By Andrew J. Petruska, Austin F. Oltmanns

This work proposes a capacitive load cell for conical picks to enable underground continuous mining machine operators to perform their roles away from known hazardous regions near the machine. The load cell is embedded in commercially available flexible printed circuit board, integrates with the target tooling, and demonstrates in situ force sensing of vibration signatures for continuous mining cutting tools. Changes in material constitution, tool mass, and tool geometry cause modal variations in vibrational response measurable with force sensors at the cutting interface. Time-series measurements are captured during rock cutting tests using a linear cutting machine. These measurements are segmented into small windows, less than 0.25 s, and are preprocessed using the fast Fourier transform, which highlights the modal variations. The transformed measurements are then classified into different material and wear categories using support-vector machines with the radial basis function kernel. Different normalization schemes and Fourier transform methods are tested for signal preprocessing. Results show that the power spectral density measurements with normally distributed coefficients give good results for material classification, while the normalized time-domain measurements give better results for wear classification. Under laboratory conditions, this technique is shown to classify material and wear categories with F1 score above 0.85 out of 1.0 for our experiment. This technology could be used to assist operators in assessing material and wear conditions from a safer distance. It has applications in the coal mining industry as well as other applications which use conical picks such as road milling.

Mar 25, 2023

By E. M. Abraham

The establishment and survival of different grass species and cultivars on various phytotechnic treatments at a limestone quarry was studied. The treatments applied were: a) bare soil, b) bentonite, c) bentonite-straw and d) asphalt-straw. According to the results, significant differences were found among species and cultivars, growing on different treatments as far as plant growth and survival are concerned. The seed germination was higher on bentonite -straw and asphaltic-straw than on bentonite but the plants survival were higher on bentonite. Lolium perenne had higher seed germination rate and better establishment than the other tested species at all treatments. However, the survival rate of Agropyron desertorum and of the cultivars palestina and chrysopigi of Dactylis glomerata was higher than of the other species.

Jan 1, 2007

By F. Sill

The disposal of residual material from processing and combustion of coal, from incineration of domestic refuse and sewage sludges kind to the environment is a prior task for the future. Deutsche Montan Technologie (DMT) has developed a new technique which makes possible to fill-up goaf cavities behind running caving systems in coalmining. In a mixing and pumping station on the surface high concentrated suspensions are produced from the above mentioned materials. The paste is pumped through pipes to the coalfaces and via trailing discharge pipes stretched to the fracture zone in the caved-in goaf. Since three years a special designed plant is working successfully on a coal mine of Ruhrkohie AG.

Jan 1, 1994

By A. Kosiór

Many remnants of gold exploitation in the Middle Ages were found in the Lower Silesia region. The oldest evidence of such activity was found in the neighborhood of Zloty Stok and comes from the 7th century. Mining of precious and non-precious metal ores has a great relevance in the late Middle Ages when advanced metallurgic technologies were mastered, that allowed to obtain gold, silver, lead, copper, zinc and arsenic from complex ores occurring in the oldest middle part of Sudetes. Historically it concerned the area of the Swidnica Principality and Klodzko County. Experience obtained in Freiberg, which is located close to the Lower Silesia, was used in the development of mining. A high level of mining and metallurgic technology was obtained in the 15th century that caused significant increase of production of the metals mentioned above. Unfortunately, the good time of Lower Silesian mining lasted only up to the 18th century; the notion of preservation of cultural heritage was unknown at that time. The Lower Silesian medieval mines were not in such a fortunate situation as the ?Wieliczka? and ?Bochnia? mines, which are operating to present-day, and which made preservation of the most interesting headings and objects possible. All these objects are now available for visitors. However, in the case of the middle Sudetes it seems that it is often sufficient to localize old shafts and headings on the basis of careful observations and old maps and carry out some earthwork to uncover medieval headings and objects of underground mining activity. They are often preserved in amazingly good state; this also pertains to mining devices. Another issue is of course the permanent preservation of that heritage and its possible availability for re-searchers and tourists. Some success has been achieved in that field (Zloty Stok Gold Mine is a good example), but also problems were encountered in many cases. The Lower Silesian Coal Basin, which has not been exploited for 10 years is an evidence that there is not a holistic conception of mining heritage renovation. Many attractive mining objects disappeared irrecoverably from the mountainous landscape of the Middle Sudetes despite common consciousness of their significance for cultural development of Silesia and other regions.

Jan 1, 2006

By M. Jessop, V. O. Kofoed, R. Blanchard, A. Hughes

Willowstick has successfully employed a new Seismic Acoustic Resonance (SAR) method to improve seepage characterization through, beneath, and around dams. SAR is a passive seismic method that detects zones of higher permeability in the foundation and fill materials of a dam. Just as the ocean has tides, the earth’s crust experiences daily “Earth Tides” and is constantly in motion. Continual motion produces resonance signals that can be measured, interpreted, and modeled to identify zones of higher permeability within a dam and its foundation. The SAR results are analyzed in conjunction with the traditional Willowstick Method to better characterize seepage flow paths and patterns trough, beneath, or around a dam in three dimensions. When both methodologies, which use entirely different scientific principles, identify the same anomalous feature, a higher degree of confidence is gained in the results of the investigation. Willowstick has effectively utilized the SAR method on many successful dam seepage investigations. The two geophysical techniques when used in parallel have yielded complimentary results, with both methods providing beneficial information about seepage locations. This paper will detail seepage flow paths identified using both Willowstick and SAR methods for two case study tailings dams in Canada and the United States.

Feb 1, 2023

By Amy McBrayer, Andrea Brickey

The paper discusses the mine planning methods used in the Powder River Basin (PRB), highlighting the differences from open-pit metal mines. It emphasizes the need for agile mine operations due to changing commodity markets and the challenges faced by the coal industry, such as volatile prices and reduced engineering manpower. The study includes a survey of mine engineers to document current practices and identify potential improvements.

Sep 1, 2023

By C. H. Bucknam

Classical acid-base accounting using modified Sobek titration methods has resulted in interpretation of results for materials with neutralization potential (NP) less than 20 tons of CaCO3/1000 tons of material (2% CaCO3) as "uncertain" due to lack of sensitivity within that content range. Standardization of a "fizzless" acid neutralization potential (ANP) method was undertaken in the American Society for Testing and Materials (ASTM) International using two ranges of sulfuric acid additions based on reaction pH and carbonate carbon estimates rather than subjective fizz testing as well as hydrogen peroxide additions to correct for mineral acidity. The method is identified as the acid neutralization potential acidity (ANPA) titration method. During interlaboratory testing a positive bias was discovered within the "uncertain" range which was further investigated and resolved by increasing the test sample weight from one to five grams for samples needing improved accuracy in materials with ANP <2% CaCO3. Test results from the interlaboratory testing of the low range method is presented and compared with the results from the original ANPA method in the paper.

Feb 27, 2013

By Perry M. Jones

An important operational and environ-mental concern associated with in situ leaching activity is the balance between solution injection and recovery. Solution balance is an important indicator of the capability of a particular in situ hydrologic design to efficiently and effectively control and distribute leach solution within the target ore zone. The Bureau of Mines is investigating the factors that affect solution balance in an unsaturated ore deposit, as part of ongoing in situ leaching hydrologic investigations at the Cyprus Casa Grande Mine. Flow conditions in 58 injection and recovery wells at the Casa Grande In Situ Leaching Test Facility were monitored daily over an 18 month period. Changes in the balance between injection and recovery occurring during this period were evaluated using analytical and statistical methods. The results permit estimation of solution distribution and the volume of solution stored in microfractures and interstitial pore spaces within the deposit following 18 months of leaching. Approximately half of the difference between well injection and well recovery can be accounted for by solution movement through macrofractures into nearby drifts. Estimates of solution storage within the ore deposit at the end of 18 months of leaching range from 3.5 to 6.9 pet. of injected solution. These results also suggest that 13 to 26 pet. of the fracture/interstitial pore space in the deposit was saturated with solution after 18 months of leaching.

Jan 1, 1991