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By Tae Hwan Lee, Jun-Shin Lee, Daejin Kwag, Sangchul Bang, Gerard T. Houlahan, Moo Sung Ryu

"Geotechnical engineers have been installing innovative, permanent underwater foundation systems utilizing suction buckets for the offshore industry since the early 1980s (Senpere and Auvergne, 1982). This foundation system has been successfully used on numerous and various types of offshore structures in a wide range of environments. Suction buckets have numerous advantages compared to conventional underwater foundation systems. The more notable advantages include easy installation, large loading capacity, low noise and retrievability. The application of reduced water pressure inside the bucket facilitates the installation of the suction buckets, where a suction pump attached at the top of the bucket can accomplish the entire driving operation. Because of this efficient operation, very large suction buckets can be driven into the seafloor, which eliminates the use of a large number of small piles.In Korea, one of the most economical and reliable renewable energy sources is wind power; however, onshore wind power generation has encountered many problems, such as the lack of favorable sites and public concerns about noise and environmental damage. Consequently, offshore wind power generation has attracted increasing attention due to its abundant potential, high efficiency of grid connection, and availability of easy expansion.In November 2011, the government of Korea announced a national offshore wind power development roadmap, which targeted its offshore wind power generation with the goal of becoming one of the top three nations in the world for offshore wind power generation. Korea Electric Power Corporation Research Institute (KEPRI) is the main research arm of the Korea Electric Power Corporation (KEPCO) and conducts research and development on electricity, power generation, renewable energy and other energy-related matters. KEPRI ultimately provides forefront knowledge and leadership to KEPCO with respect to energy and related areas for its near- and long-term needs. Financial support for the overall project, of which the suction bucket foundation system installed for the pilot phase wind turbine is described below, was provided from the New and Renewable Energy Program of the Korea Institute of Energy Technology Evaluation and Planning funded by the Korean Government Ministry of Trade, Industry and Energy"

Jan 1, 2017

By P. T. Bissert, J. P. Ducarme, J. D. Noll, C. C. Jobes

"There have been about 42 fatalities in underground coal mines between 1984 and 2015 where the victim was struck, pinned, or run over by a mobile machine (MM) such as a shuttle car, scoop, or battery hauler. MSHA has issued a proposed rule requiring proximity detection systems (PDS) on MMs in an effort to prevent future fatalities. Currently approved PDSs use electromagnetic (EM) technology to detect the presence of a miner and impose machine controls to prevent contact. The disadvantages of an EM-based PDS on MMs include the need for a miner-wearable component (MWC), environmental interferences, EM interferences from other devices, and low localization range and accuracy. NIOSH researchers are investigating alternate technologies that could improve the capabilities of the current PDSs. Many technologies were reviewed, and NIOSH researchers identified RFID, LIDAR, RADAR, ultrasonic detection, and computer vision as candidates for PDS development. The performance characteristics of each technology and its applicability to an underground mining environment will be discussed, along with international developments and implementations, and the concept of sensor fusion. INTRODUCTION PDSs provide safety to mine workers by detecting their presence (and in some cases location) around a machine. These PDSs provide a warning zone, which triggers an alarm, and a stop zone, which halts the machine before it contacts the miner. The Mine Safety and Health Administration (MSHA) issued a final rule requiring that PDSs be installed on all continuous mining machines (CMMs) on the working section, with the exception of full-faced machines, according to a phase-in schedule for newly manufactured and existing equipment [1]. The PDSs that were designed for CMMs have since been adapted to other mobile machines. Mobile machines include scoops, which are used as general utility vehicles, as well as coal hauling machines, such as shuttle cars, ram cars, and continuous haulage systems. MSHA has examined all accident reports from 1984 to 2014, and determined that 42 fatalities could have been prevented on mobile machines had a PDS been installed [2]. As such, MSHA issued a proposed rule that would require mobile machines on working sections (with the exception of longwall sections) to be equipped with a PDS. This rule would follow a phase-in schedule for newly manufactured and existing equipment. Currently available PDSs are based on electromagnetic (EM) technology. NIOSH researchers developed a shell-based magnetic flux density distribution model [3] for determining the position of a miner near a machine. A typical system would consist of four generators positioned around the perimeter of the machine. Each generator is a coil of insulated wire wrapped around a ferrite core. The magnetic field strength is proportional to the current running through the coil. Miners working on the section have an MWC, which is a transceiver that measures the field strength emitted by the generators and transmits a data packet over an RF link which contains the field strength reading to the PDS controller mounted on the machine. The magnetic field generators are pulsed sequentially such that the MWC can identify which generator’s field strength it is reading. This type of system utilizes the principle of magnetic flux density: the closer the MWC is to the field generators, the higher the field strength reading. Thus a miner’s presence can be determined once he gets too close to the machine, because his MWC will measure a magnetic flux density beyond a certain threshold. These thresholds are utilized on a per-generator basis to “shape” the fields for both warning and stop zones around a machine, as illustrated in Figure 1."

Jan 1, 2017

By Debra Satkowiak, Ronald Thomas

The Institute of Makers of Explosives (IME), a non-profit safety and security organization founded in 1913, is known for its industry best practices, Safety Library Publications (SLP), some of which have been incorporated into rules by regulatory agencies. The IME developed the first commercial storage, quantity distance (Q/D) table titled “The American Table of Distances” (ATD). It was developed by IME’s legacy association in 1910 and was originally based on observations of structural damage from 117 accidental explosions involving small to very large amounts of explosives, primarily dynamite and black powder. In 1930, the IME published a book, compiled by Ralph Assheton, called the “History of Explosions on Which the American Table of Distances was Based”. The distance in feet in the ATD were founded on the measurements at which inhabited buildings sustained substantial structural damage from the accidental detonation of explosives. For example, minor damage such as window glass breakage and the “shaking down” of plaster was not considered substantial structural damage. Other damage to property that was readily repairable was also not considered “substantial.” It was concluded that unless some integral portion of the building was damaged, the occupants would not be subjected to serious risks.

Jan 1, 2017

By K. D. Dill, S. D. Rosenthal

"This project analyzed the efficiency of incorporating the use of directional drilling technology into coal overburden blasting. Directional drilling is currently in use in the petroleum industry and it is believed that it will be a valuable asset in the mining industry. This project has shown that directional drilling can be a viable technology for use in the coal overburden removal process resulting in increased drill utilization and potential for cost savings. Future work regarding blasting and geotechnical evaluation should be performed to solidify the concept. INTRODUCTION Determine the Potential Drill Utilization Improvements and Rock Fragmentation Requirements Using Directional Drilling in a Coal Mining Overburden Highwall Application was a project funded by Atlas Copco Drilling Solutions (Atlas Copco) based in Garland, Texas. The project was developed and researched by Montana Tech of the University of Montana. This project was intended to show how the use of directional drilling can increase drill utilization, while decreasing costs, without sacrificing overburden blasting results. This paper discusses a review of the literature, the methods performed, conclusions and future work Background Atlas Copco theorized that an alternative approach to drilling a cast blast pattern would be beneficial to coal mining operations by increasing drill utilization and therefore, decreasing overall costs. Increasing drill utilization results in an increase in the amount of time the drill is being productive, more drill bit time in ground. Atlas Copco’s theory is that by incorporating directional drilling in the design of a cast blast pattern, a drill rig could drill multiple directional holes, which are the length of the cast blast, from a single drill set up. A drill goes through a series of steps to complete a blast pattern, these steps include: tramming to the hole location, leveling the drill, drilling the hole, cleaning the hole, and retracting the drill steel. This process is repeated hundreds of times until the whole pattern is completed. The most time intensive part of this process is drilling out the blast pattern. Integrating directional drilling into this process could decrease the overall time it takes to drill out a blast pattern by minimizing the amount of time spent tramming and setting up for each subsequent hole. Tramming and drill set up are two aspects of the drilling process where the drill tool is not engaged with the ground and, therefore, not being utilized. A cast blast pattern designed to utilize directional drilling will allow the drill tool to be “in the hole” longer and will improve drill utilization. This change in drill utilization was analyzed. Drilling and blasting is an integral part of the mining process, without it mining would be a slower process and less material could be mined. Drilling provides holes for explosives to be loaded and then blasted. Blasting has been found to be the most cost effective method of fracturing rock in mining for material removal. Blasting is also used as a low-cost method to move the rock in open cast mines, commonly referred to as cast blasting. A cast blast is a large blast designed to allow for the maximum amount of overburden to be removed using explosives in a single blast thereby uncovering more coal at a lower cost. Not all the material is blasted to cast-to-final, which requires that material to be moved with large mining machinery. Material that is considered cast-to-final is material that has been thrown far enough to never be moved again in the coal extraction process, therefore it is in its final resting place. A typical cast profile and cast-to-final area is shown in Figure 1."

Jan 1, 2017

By J. R. Patts, J. P. Rider, J. A. Organiscak, A. B. Cecala

"NIOSH recently completed a 15-month study at an underground limestone mine crusher booth which evaluated three research parameters: (1) the effectiveness of a single-filter filtration and pressurization system for improving the air quality inside the operator booth, (2) comparing the effectiveness of ? > 99 and ? > 95 experimental prototype filters in the system, and (3) evaluating the use of three different pressure monitoring devices to determine the performance of the filtration and pressurization system over time. The protection factor was quantified monthly using particle counters in the respirable dust range (0.3–10 µm), and gravimetric dust samples were gathered at the beginning and end of the overall study. Under static conditions and after outlier removal, the single-filter filtration unit installed offered a protection factor between 8 and 216, depending on the filter type and loading condition. The particle counting analysis shows that the ? > 95 filter offers a protection factor greater than 4-times that of the ? > 99 filter when evaluated over 60 minutes. The booth pressure monitors provided data that proved to be a valid indicator of system performance over time. INTRODUCTION Designed and installed correctly, enclosed cabs, operator booths and control rooms offer mine workers protection from physical hazards, such as flying rock, debris, and noise, as well as a more comfortable environment in regards to temperature and humidity [1]. But while it may be easier to quantify whether the A/C unit is working (measuring the temperature) or observe whether the cab offers protection from flying debris, it can be somewhat more difficult to quantify its performance in reducing respirable dust hazards. For over 15 years, NIOSH has been conducting applied research to improve the air quality inside of enclosed cabs of mobile equipment [2-5]. This work has led to the identification and mathematical modeling of enclosed cab filtration systems [6]. The same principles that govern the performance of filtration systems on mobile equipment are applicable to stationary enclosures such as operator booths and control rooms [1, 7]. Stationary enclosures are similar to enclosed cabs; however, the volume of the work area can be significantly larger. In addition, workers who perform their duties in stationary enclosures tend to stay within the room for a greater percentage of the day, as opposed to workers on mobile equipment who may enter and exit frequently. Structural integrity can be easier to maintain as well, as there is typically less vibration and stress placed on these compartments as compared to mobile equipment. In addition to offering protection from dust and flying debris, enclosures must ensure that workers have a healthy supply of fresh air to avoid elevated levels of CO2, which are known to cause headache and dizziness, impairing cognitive function. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) states that enclosures should have no more than 1,100 ppm of CO2 when outside levels are 400 ppm [8]. In addition, the American Society of Agricultural and Biological Engineering (ASABE) recommends a minimum airflow for enclosed cabs of at least 42.5 m3/hr (25.0 cfm) per person [9] to ensure an acceptable level of CO2."

Jan 1, 2017

By E. Jong, E. Watkins

"The application of passive tracer gas sources in underground mines is particularly useful for long-term tracer gas studies, as well as for studies in permissible areas of underground coal mines. The use of passive perfluoromethylcyclohexane (PMCH) sources have previously been demonstrated in mines, but this new work details the development and testing of multiple, distinct tracer compounds that can be used in passive sources. A description of their potential application in mine ventilation systems is also provided. Three tracer compounds are detailed, which are PMCH, PECH and PMCP. The release rates of these tracers were examined over a 180 day period at multiple temperatures. The advantages and disadvantages of these sources are presented, along with potential applications in understanding complicated ventilation circuits, flow through gob, and leakage. INTRODUCTION The use tracer gases for ventilation applications is an established practice, with various research projects being perform with Sulfur Hexafluoride (????6) in the past. Perfluorocarbon tracers (PFTs) however are relatively new compared to ????6, which is proven to be useful in ventilation and air modeling experiments along with other PFTs (Watson, Wilke, Dietz, Heiser, & Kalb, 2007). These liquid tracers are characterized by low background presence in air, inert behavior with other gases, high detectability with a gas chromatograph and low toxicity. A design was proposed called a permeation plug release vessel (PPRV), which initially introduced by Brookhaven National Laboratory to meet those requirements. The PPRV works by allowing the gaseous form of the tracer to diffuse through the permeable silicone stopper and evaporate into the open air on the other side. The PFTs inside the vessels are injected as a liquid but instantly begin to convert to their gaseous phases at room temperature due to high vapor pressures (Zhang, H., Cloud, A.,2006). Previous studies have detailed how release rates change based on plug thickness across various temperatures (Jong et al., 2015), but not on the release rate stability based on temperature across multiple tracers. For use in underground mines passive release sources need to be durable, be simple to manufacture, have customizable and reliable release rates as well as a long operating life. The PPRV vessel provides a steady release of tracer gas that is essential for long term passive release experiments, making it a viable vessel for the PFTs being tested. The PPRV design also allows for vessels to be bundled together to achieve release rates at detectable levels and allows for the capability to run ventilation surveys with multiple tracers simultaneously. The ability to conduct ventilation surveys with multiple tracers using the PPRV bundling design and detection of the PFTs makes testing the tracers and design together a promising potential for complex and long term mine ventilations studies."

Jan 1, 2017

By Frank Hirthammer

"Nowadays, security in the lifecycle of explosives is more important than ever. Terror attacks all over theworld pushed the EU to decree a Commission Directive for the identification and traceability of explosives that set a series of requirements for involved manufacturers, distributors and end-users. The challenge was to find and implement a track and trace system for all concerned European companies byApril 5, 2015. Since then, countries worldwide have followed this example and implemented similarregulations."

Jan 1, 2017

By Nabil F. Ismael, Khalid Farraj

"The axial load transfer along large diameter bored piles in very dense silty sand was examined by field tests. Two instrumented piles 1.2 m diameter and with embedded length of 18 m and 25 m were load tested in axial compression to failure in connection with the construction of a big tower building in Kuwait City, Kuwait. Instrumentation included vibrating wire strain gages at various levels, displacement transducers and extensometers. The purpose being to measure the axial load distribution, skin friction, and base resistance at various load levels. In addition the settlement of the piles and the elastic compression were monitored. The ultimate pile capacity, side friction, and base resistance were determined and correlated with the Standard Penetration Resistance values as determined from the boreholes. Most of the load was transferred as side friction and the pile settlements at the maximum loads ranged from 1.6% to 2.2% of the pile diameter.INTRODUCTIONLarge diameter bored piles are used with increasing frequency for heavy structures in Kuwait and the Gulf region in calcareous sand. The behavior of short piles ranging in depth from 8 m to 15 m was examined by field test (Ismael 2012). However, larger diameter and deeper piles are being used more frequently, including the project described in this paper which included piles with 1.2 m diameter and 18 m to 25 m depth. The design of these piles requires knowledge of the skin friction and point resistance in these soils. While field tests on driven piles are available (Ismael 1989, Ismael 1999), field test data on long large diameter piles installed through very dense sands or silty sands are very limited at present. The results of two load tests carried out recently on instrumented bored piles at one site in downtown Kuwait City have become available. In these tests the failure load was extrapolated from the test results. It is important to examine and analyze the test results for the benefit of the geotechnical research and design engineers."

Jan 1, 2017

By Shintaro Takamiya, Kazunari Yoshida

"Recently, small sized micro-needles for medical are required more frequently by patients. The biggest reason is that it presents great burden on the patients, due to the size of the needle injection. People need to use a very small needle to lower the pain, but the downfall is that it makes them more expensive due to their complicated manufacturing method. Therefore, we need to fabricate a needle by wire-drawing to decrease its price. Tube-drawing is beneficial for its production value; however, in conventional tube-drawing it is difficult of control the wall thickness of the tube and makes it 1mmor lower in diameter. That is why, we propose fluid-mandrel drawing for new tube drawing. This method allows fabrication of a fine tube by using the pressure of the fluid in the tube. In this research, the goal is the fabrication of a fine tube by fluid-mandrel drawing and its evaluation. Finally, the fabrication of a fine tube by fluid-mandrel drawing was conducted and in result a tube with a diameter of 0.2mm, high strength and thin wall and fine inner surface was drawn, which can be used as a lesser pain micro-needle.INTRODUCTIONThe main manufacturing method of the current medical needles is roll forming. With this method, it is difficult to make a tube with a diameter lower than 1mm. Deep drawing has been proposed and used as method to further reduce the diameter, but this method is costly and the injection needle obtained by this method is several times more expensive.Therefore, we need to obtain a fine medical needle by drawing process that can be mass-produced and inexpensively manufactured. However, with the conventional drawing process, it is not possible to obtain a syringe needle with a reduced diameter easily, that is why, a fluid-mandrel drawing has been proposed which can reduce the diameter without damaging the inner surface. The methodology of the method is, a fluid is filled in the sealed tube and the pressure inside the tube during drawing is responsible for the good inner surface and wall thickness. It is also expected that the fluid can be easily discarded and that the tube can be manufactured on a long scale."

Jan 1, 2017

By Inc. Pile Dynamics, Daniel S. Belardo, Marcus Galvan, George Piscsalko

Soil nails are often utilized as a temporary or permanent earth retention technique for slope stabilization and for excavation retention for existing or new structures. Soils nails are generally advantageous as installation is relatively rapid and they can be installed beneath existing structures and where site access for equipment is limited. Due to the typically small cross-section of these elements, the inability to inspect the holes prior to grouting/concreting, and the various installation techniques utilized, quality control for assessing the integrity along the entire length is limited. Currently, quality assurance is conducted by load testing to verify the pull out capacity after installation. The load testing is typically done on a small percentage of the total number of soil nails. This paper will provide the results of a demonstration where the new Non-Destructive Test (NDT) method Thermal Integrity Profiling (TIP) was used to access the integrity of several soil nails along their entire lengths. This TIP method has been successfully used for several years to assess the integrity in drilled shafts and ACIP piles. The TIP method assesses the integrity across the entire cross-section and can identify regions where bulges, necks, and insufficient grout/concrete are present. TIP testing can also help assure that the contractor's installation methods are adequate and consistent for the intended design. For the project presented, instrumented Thermal Wire were affixed to the centered tension bars prior to placement in the excavated shafts. Temperature measurements were recorded from the hydration energy generated after grout/concrete placement, capturing the entire heating cycle. Manufactured defects were installed on the center bar at multiple locations. The results and conclusion will be discussed as well as recommendations for future use.

Jan 1, 2017

By Timothy Batchler

"Standing roof supports help to provide a stable working environment in coal mine gateroads. NIOSH participates in the development of these support systems by conducting full-scale tests in their Mine Roof Simulator. These tests have established the performance characteristics of every coal mine support system currently in use in the United States. Through these tests, mine operators and regulatory officials have acquired a fundamental understanding of the various types of support performance that guides the assessment and use of these support systems. However, some little known factors that influence support behavior can lead to misconceptions and, perhaps, a poor assessment of support behavior at times. This paper highlights several of these factors and discusses their significance. The paper also examines a current longwall tailgate support and discusses the inefficiency with this approach. Finally, the NIOSH Mine Roof Simulator (MRS) is the world’s most powerful load frame built specifically to test full-scale roof supports, including longwall shields. are addressed in this paper to provide a more in-depth assessment of the limitations of the MRS and what the MRS testing protocol is designed to do. INTRODUCTION Over the years, considerable research has been conducted to develop standing support technologies and to evaluate their performance characteristics. The load and displacement characteristics of the standing supports have been determined from full-scale testing conducted using the National Institute for Occupational Safety and Health (NIOSH) Mine Roof Simulator (MRS) (Barczak and Tadolini, 2008) located in Bruceton, PA. Performance traits, installation patterns, and ground responses are observed in various geological and mining conditions and are evaluated to determine the support performance in the field (Dolinar, 2010; Campoli, 2015; Zhang et al., 2012). Despite widespread use of standing supports, not every aspect of their performance and resulting ground support capability are always well understood. This paper discusses 10 factors, several of which are surprising, that impact standing support performance."

Jan 1, 2017

By L. Cong, C. Liu, N. Zhang, W. Cao, C. Zhou, X. Fan

"The modes of occurrence of arsenic and the effects of low-intensity leaching-flotation on arsenic removal from coal slime from the Tanggongta Plant, Inner Mongolia, China were investigated. The coal slime was examined using hydride generation inductively coupled plasma optical emission spectrometry and X-ray diffraction to obtain the content of elements and the major minerals. The modes of occurrence of arsenic in minerals were determined using selective leaching, float-and-sink analysis, and polarized light microscopy. The results indicate that pyrite is the dominant carrier of arsenic in the coal slime, which predominantly exists in association with clay. Significant proportion of the arsenic is removed by a low-intensity leaching-flotation process, consistent with the data from selective leaching and flotation of gangue. The results show that low intensity leaching-alkali washing-flotation is more efficient than direct flotation and low-intensity leaching-flotation.IntroductionUnderstanding the occurrence of arsenic in coal and its removal is significant in optimizing coal utilization, because arsenic in the environment is viewed as a potentially toxic trace element (Finkelman, Belkin, and Zhang, 1999; Hall, 2002; Smith et al., 1992; Smedley et al., 2003; Zheng et al., 1999). Many studies on the modes of occurrence and concentration trends of arsenic in different coal and washing products have been performed (Diehl, Goldhaber, and Hatch, 2004; Kolker et al., 2000; Quick and Irons, 2002; Wang et al., 2006; Fan et al., 2016). Trace elements are usually preferentially associated with certain minerals and the form that these minerals take will influence the efficiency of removal during cleaning (Quick and Irons, 2002). Arsenic is mainly associated with minerals such as pyrite, carbonate, and silicate (Demir et al., 1998; Diehl, Goldhaber, and Hatch, 2004; Zhou et al., 2014). The existence of organically bound arsenic was also confirmed using X-ray absorption (Kolker et al., 2000). However, inorganic arsenic is the principal source of pollution because of its leachability and high concentration compared with organic arsenic (Fujino et al., 2004; Gao, Lu, and Wang, 2010; Jiang et al., 2008; Kolker et al., 2000)."

Jan 1, 2017

By Qinghua Song, Jianhong Chen, Shan Yang, Zhiyong Zhou

"The development process of Metal Resources Technical and Economic Evaluation Expert System (MRTEEES) is introduced in the aspects of requirements analysis, design of the expert system, main functions of the expert system and features of the expert system. The system is based on C/B/S mixed mode and uses ASP.NET technology with .Net Framework being chosen as the development platform and metal resources database providing data support at the bottom layer. The system is an auxiliary management system for metal resources technical and economic evaluation and has the basic functions of auxiliary decision analysis, metal resources database management, data management and comprehensive query. Technical and economic evaluation model can be set up by users independently according to at which stage a project is, mainly including exploration stage, development stage and production stage, and according to the mining methods, for example underground mining, surface mining and in-situ leaching mining. Then, the technical and economic evaluation parameters can be generated. By inputting the value of each parameter in a simple and convenient way, the evaluation results can be directly calculated out and shown in the form of diagrams among others, and feasibility evaluation report can also be automatically generated, making the technical and economic evaluation process accurate and efficient. As the system can achieve the functions of scenario analysis, sensitivity analysis, shareholder’s returns analysis, horizontal comparison of different projects, it can improve the ability of project senior decision makers for rapid response to the rival and meet the demand of pricing negotiations. IntroductionWith the arrival of a new round of industrialization upsurge in both developing and developed countries, growth of demand for metal resources is entering a new stage. Population involved in the new industrialized countries is about four times that of all previous industrialized countries, implying resource consumption increases dramatically both in speed and in quantity. It is a must to seize the strategic opportunity of developing and utilizing metal resources around the world to lay abundant resource base for national industrialization. Objectively speaking, global configuration of metal resources is an inevitable tend. Presently, many issues, for example, resources exploration, mining, merge of mining companies, metal trades, mining financing, etc., generally show the feature of globalization. For the reality that competition for metal resources is becoming fiercer, industry standards of mineral resources will undoubtedly be improved. Occupying large scale mineral resources with high grade and developing them with low cost is the base for the survival of mining companies and metal resources merchants. With the growing demand of global investment in mineral resources exploration, which is at the upstream of the industry chain, geological exploration industry is promising. Globally building market relationships for mineral resources exploration companies is key to their sustainable development. Developing large and super-large deposit with low cost is also an important approach to enhancing core competence of a country or an enterprise. Mining companies around the world are rushing to purchase mineral resources globally. However, in different countries, economic, financial and tax systems for mineral resources vary greatly, and mining and processing techniques, technical parameters and equipment selection also change a lot. Thus, pro-phase research work is necessary for feasibility evaluation of mineral resources projects and it can be time wasting if taken in the traditional way. It is necessary to accelerate the process considering the complex and rapidly changing international situation."

Jan 1, 2017

By Thomas Kuhn, Anna Wegorzewski

"INTRODUCTIONPolymetallic nodules from the Clarion and Clipperton Zone (CCZ) within the equatorial NE Pacific Ocean show high concentration of economic important strategic metals such as Ni, Cu, Co, Mo and Rare Earth Elements (REE). The content of those metals in nodules is depending on (i) the supply during individual growing periods, (ii) the environment conditions as well as (iii) on different manganese minerals, which occur in nodules. The incorporation of the metals can vary within the structure (incorporated into the structure / over vacancies of the structure) and this can be relevant for the further metallurgical treatment.Mineralogy of Mn-nodules from the CCZ and the incorporation of metalsManganese nodules consist of nm to µm thick layer growth structures (LGS) of different genetic origin (hydrogenetic/suboxic-diagenetic). Those LGS form due to the precipitation of Mn-and Fe-(oxy) hydroxide colloids from the oxygen rich near-bottom water and/or pore water (hydrogenetic growth; Halbach et al., 1988) or from suboxic (depleted in O2 <5µmol O2/l; Hein and Koschinsky 2013)) near-bottom water/pore water (suboxicdiagenetic growth; Halbach et al., 1988; Wegorzewski and Kuhn, 2014).In general, metals dissolved in seawater will be adsorbed and complexed on the oxide surfaces according to their different surface charge. The surface charge of the Mn-Fe (oxy) hydroxides depends on the pHzpc (zpc: zero point of charge). In seawater dissolved hydrated cations (Ni2+, Cu2+, Co2+) are adsorbed preferentially on the negatively charged Mn-oxide (MnO2 -) surface (pHzpc 2.8). In contrast, negatively and neutrally charged complexes (e.g., Ti(OH4); REE(CO3)2 -, MoO4 2-) are adsorbed on the surface of Fe-oxy hydroxide colloids (FeOOH+) which have a slightly positively charged surface (pHzpc 8.5; Stumm and Morgan, 1981; Koschinsky and Halbach 1995)."

Jan 1, 2017

By R. L. Miller

"Miners worldwide use a tremendous amount of energy in producing finished minerals for the end user market. In accomplishing this goal, they incur energy costs that can range from 20% to 30% of the total cost of production, so there is fertile ground for cost savings. To unlock this huge value in cost reduction, energy analysis is the key and is broken into several segments: 1. Fuel analysis for power generation 2. Energy supply & demand 3. Opportunity cost for lack of power 4. Backup power 5. Power contracts 6. Energy efficiency 7. Renewable energy 8. Continuous energy management FUEL ANALYSIS FOR POWER GENERATION What is the first thing we evaluate when looking at power supply alternatives for the mining industry’s large power requirements? Is it 1) site, 2) engineering, procurement, and construction companies, 3) independent power producers, 4) turbine vendors, 5) grid connections, or 6) fuel supply, logistics, and infrastructure? In evaluations of power supply alternatives for mining companies with special emphasis in developing countries, there is one over-riding conclusion: reliable fuel supply drives the energy generation economic engine. Evaluating several different fuels including liquefied natural gas (LNG), natural gas, diesel, heavy fuel oil, and liquefied petroleum gases (LPG) among others, the best project outcomes are those where fuel supply, pricing, logistics, and infrastructure are given an extensive amount of time during the analysis stage. In an assessment of the twenty-year costs of generating power from multiple fuels, each fuel’s costs were placed into three separate net present value (NPV) buckets of: 1) capital, 2) operating and maintenance, and 3) fuel. Within a range of 65% to 85% for all fuels, fuel cost was the largest component of the NPV of the life cycle power generation costs. So if 65% to 85% of your life cycle power generation cost is one item, shouldn’t miners spend a corresponding amount of time in the analysis stage fully understanding this key determinant for a successful power project? In developing countries where power generation infrastructure may not exist or does not exist at the same level as is found in North America and Europe, fuel analysis becomes even more important. One of the key questions for fuel importation in developing countries is the draft at existing ports to allow larger vessels to dock at the jetty. Can larger ocean-going tankers dock at the port for off-loading, or is the port’s draft too shallow, thus forcing a Single Point Mooring (SPM) system or Conventional Buoy Mooring (CBM) system to be constructed at substantial capital expense? Once fuel can be imported, sufficient onshore storage capacity should exist, or must be built to off-load the entire fuel cargo from the larger ships. Additionally, the throughput capacity of the pipeline from SPM/CBM must allow a rapid unloading of the fuel from ship to shore to eliminate steep demurrage costs for the project."

Jan 1, 2017

By Eduardo Lozano, Vilem Petr

The use of explosives brings countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition, and avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation.

Jan 1, 2017

By M. V. Rowley, D. D. Warkentin

With high commodity prices, tightening operating budgets and increasing disposal costs, there is an increasing interest in processing municipal waste streams, such as the ash derived from combustion processes. This paper describes laboratory development work for a process to recover metal values from the finer fractions of these wastes. The work was initially aimed at recovery of copper and the removal of lead and other heavy metals from the ash residue, but results showed gold and silver recovery to be an important objective as well. The process uses gravity and flotation as the principal separation steps, with gold recovery occurring mainly in the flotation stage. The particle size range and chemistry of the ash presented numerous challenges to developing a suitable flotation method, but an effective flowsheet was developed by separating the ash into a fine fraction and a separate slime fraction, each with a unique flotation strategy. Specialized conditioning stages and careful reagent selection have resulted in effective gold and silver recovery from a range of ash types and sources. The work has resulted in a patent being issued for a process based on this novel approach to the treatment of combustion wastes.

Jan 1, 2017

"Real-time, on belt analysis of minerals is becoming increasingly important and critical in modern operations, especially in the mine-to-mill. Prompt gamma neutron activation analysis has long been utilised for real-time elemental analysis in bulk materials, with Scantech's GEOSCAN being the instrument of choice in the minerals sector. Working in the minerals space for 15 years, the GEOSCAN has been successfully implemented in a wide range of minerals applications including iron, copper, lead-zinc, manganese, phosphate and more, and it caters for the very high demands and increasing requirements of a contemporary processing facility. An area of focus has been on increasing the analysis frequency to allow for rapid analysis results with the same high degree of accuracy typically expected of the GEOSCAN. This paper discusses the underlying research and technology that has enabled such rapid analysis and presents a range of examples using a thorough statistical approach on real production material, demonstrating achievable accuracy over a short analysis time, and dispelling common myths about the speed of the technique. Potential applications are discussed to conclude the paper.INTRODUCTION Technology and the information it can provide plays a critical role in the evolving modern mineral processing landscape. The importance of technology to analyse various features of ores and concentrates being processed is obvious, and recent years has seen the advance of numerous technologies to provide a variety of real-time measurements on conveyed material flows. From sampling apparatus to particle size analysis to weight and density meters to full elemental analysis, the availability of information enables a variety of improvements in the process leading to improved efficiency and increased revenue. To maximise the potential benefits, access to real-time information is imperative, and rapid updates of information become necessary to make appropriate process control decisions based on the most relevant and up-to-date information."

Jan 1, 2017

By Jamal Rostami, Asok Ray, Samer S. Saab Jr., Wenpeng Liu

Ground instability, such as roof or rib failures, is one of the most serious and frequent safety hazards that occur in underground mining, tunneling, and underground construction. The ground-related parameters and features of interest, in assessing roof or rib failures, are location, frequency, and orientation of the joints, voids, as well as rock-strength. These parameters are the main components of rock mass characterization that offers effective strategies for ground support, which, in turn, allow one to mitigate the risks related to ground instability. The main objective of this study is to determine the location of joints and classify rock-strengths by analyzing the drilling data recorded from an instrumented roof bolter while drilling for rock bolt installation during the operational cycle. For this purpose, computer programs based on updated pattern recognition algorithms were developed for joint-detection and classification of rock types to offer an estimated strength. This paper briefly introduces ongoing research on joint detection, especially for joints with an aperture less than 0.125in (3.175mm), by employing an instrumented roof bolter in controlled environments. To improve the capability and precision of joint detection programs in detecting the joints from the drilling data and reducing the number of false alarms, many laboratory tests with various simulated joints and rock-strengths were carried out at a J.H. Fletcher & Co. facility. This paper reviews testing procedures, data analysis, updated algorithms used for joint detection, and discusses the latest round of testing in samples with simulated joints at various angles along the borehole.

Jan 1, 2017

By Dhanaji S. Chavan, Thallak G. Sitharam

"It is well known that sites comprising of saturated loose sand undergoes large deformations, due to liquefaction, during seismic shaking. To cope with this, different mitigation techniques such as vibroflotation, deep dynamic compaction, compaction grouting, deep soil mixing etc. have been used in practice. However, as all these methods are costly, a new mitigation technique is required. Air injection has emerged as a new mitigation technique in which air is injected into the saturated loose sand. The introduced air makes the pore fluid mixture compressible and results into decrease in the generation of excess pore water pressure during seismic shaking. This paper reviews the laboratory and field studies performed to investigate the effect of air injection on liquefaction resistance. In addition to this, previous research in the direction of desaturation has evolved different techniques to generate gas in saturated sand. These techniques have also been discussed in the present paper. All the field and laboratory studies have shown that even a slight decrease in the degree of saturation increases the liquefaction resistance significantly.Keywords: desaturation, air injection, liquefaction resistance, pore pressureINTRODUCTIONEarthquake events in the past, caused liquefaction of loose saturated sands at many sites in the world. The consequence of liquefaction varied from small deformations to catastrophic failures such as flow slides, lateral spreading, sand boiling etc. (Kramer, 1996). To reduce the liquefaction potential of such soils, different mitigation techniques have emerged across the world. Some of the most widely used mitigation techniques are vibroflotation, deep dynamic compaction, compaction grouting and deep soil mixing (Idriss and Boulanger, 2008).Yoshimi et al. (1989) found that the liquefaction resistance of partially saturated sand is significantly higher than that of saturated loose sand. Further, Pietruszczak et al. (2003) proposed desaturation of the saturated loose sand as a new liquefaction mitigation technique. It is observed that the liquefaction resistance of sandy soil is enhanced significantly owing to the desaturation caused during construction of sand compaction piles (Ishihara et al. 2003). Over past few years research is being carried out on desaturation of sandy soil and its liquefaction resistance ( Ishihara et al. 2003; Okamura and Soga 2006; Yegian et al. 2006; Yegian et al. 2007; Takemura et al. 2009; Eseller-bayat et al. 2013; He et al. 2013; Marasini and Okamura 2015; Zeybek and Madabhushi 2016). As a result of this, different techniques of desaturation have also emerged. Different studies conducted in this direction and their outcome has been discussed in the section to follow."

Jan 1, 2017