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By R. Sripriya, Ch. V. G. K. Murty, N. D. Rao, P. V. T. Rao, A. Ramu

Studies were carried out to improve the performance of hydrocyclones at Tata Steel's chrome ore beneficiation plant in Sukinda, India. The optimal cut point of the hydrocyclones was determined in the laboratory using a stub cyclone. In the tests, the operating and design variables, including spigot diameter, density of feed slurry and inlet pressure, were varied. Subsequently, plant trials were carried out, and attempts were made to develop a model of the hydrocyclone using the Rao, Lynch and Plitt model. The cyclone efficiency was represented by the parti¬tion curve, and the performance was evaluated mathematically from a reduced efficiency curve, represented by the equation:

Jan 1, 2000

By John Petty, John Loviza

As a blaster, have you ever had that uneasy feeing in the pit of your stomach as a codes enforcement official drives onto your jobsite? Have you ever needed an ally in a court of law against an unjust damage claim? Have you ever wished for a better and more open relationship with the guys who wear the badges?

Jan 1, 1996

By Ralph E. Hartline, Wilfred Tapper

The Strataflow process for locating water entry in producing, wells is now available. This method as now practiced utilizes the fact that fluids of different salinities have different electrical resistivities. By introducing into the well a fluid of a markedly different salinity than that of the fluid being produced, a pronounced resistivity change will occur at the point of entry. By running a Strataflow survey the points of major and minor water entry may be interpreted from changes in the resistivity of fluid in the hole. Strataflow results are obtained with the well operating under almost normal producing conditions, and are a logical primary step in any workover program, having as its purpose shutting off of the water. INTRODUCTION Water production is a serious problem in many producing oil wells. It certainly increases lifting costs and in some cases presents a disposal problem. It often aggravates corrosion problems and can even endanger oil production. With accurate information to guide an effective workover program, many marginal wells could be restored to Profitable Production. The shortcomings of previous meth- ods of water entry location were recognized. The Strataflow process is the result of several years of development and field testing directed toward overcoming these limitations. It represents the continued development of a process reported by Silverman and Brown. The earlier work established the basic soundness of fresh-to-salt water resistivity contrast in delineating zones of water entry, but its application was limited by the difficulty of maintaining static balance of the well during preparation for the test. A more serious deterrent to its use, however. was its unadaptability to existing well logging service equipment and field operating methods. STRATAFLOW PRINCIPLE The general principle of the new method involves, first, conditioning the well by displacing the fluid in the bore of the well adjacent to the zone to be tested by a conditioning fluid which is miscible with the formation fluid. This displacement is carried out without interruption of the well production. The conditioning fluid must have some measurable physical, chemical, nuclear, or electrical property which is distinctive from that of the formation fluid. As the well continues to produce. formation liquid entering the well bore dilutes the conditioning fluid so that zones of entry may be determined by making a log of the property undergoing change. This general principle may be applied to indicate zones of either water or oil entry by suitable selection of conditioning fluid and proper logging equipment. The Strataflow process, as it is currently practiced for water entry location, uses fresh water as the conditioning fluid and depends for its operation upon the marked difference of electrical resistivity between this fresh water and the salty water produced by the formations. If possible. any necessary modifications of the well equipment are made a week or so before the test. The well is then returned to normal production. On the day the test is to be carried out. the conditioning water is landed at the bottom of the well and the test is made without interrupting production except for a brief period required for the conditioning water to consolidate into a continuous column extending to a point well above the test section. With this general description of the process in mind, a more detailed step-by-step description of the process will be clearer. PRELIMINARY PREPARATION OF WELL The Strataflow survey, as it is currently practiced for water entry location, is applicable only to pumping wells. Since the required electrical measurements are made by a special

Jan 1, 1952

By J. W. Jang

The wear behaviors of grinding media with different chemical compositions and microstructures in wet grinding of a quartz-pyrrhotite mixture was investigated under various environments. The marked ball wear tests showed that the wear rate could be minimized by a suitable combination of martensite and ferrite within the same ball. A ball composed solely of hard martensite exhibited increased wear under an oxygen environment, while balls composed of both soft ferrite together with hard martensite exhibited decreased wear due presumably to the difference in their passivation? behaviors. The galvanic interactions between the two phases as well as among these phases and an electroactive mineral were investigated through electrochemical measurements under abrasive conditions in a slurry. The rates of formation of passive films controlled the corrosion currents of the high chromium steel media. Corrosive wear and its effect on flotation are discussed using the passivation kinetics model thereby developed.

Jan 1, 1989

By Tumilty JA, Douglas WD

With a view to characterising activated carbons with respect to their ability to adsorb gold from cyanide solutions, an attempt was made to establish correlations between the equilibrium capacity constant of the activated carbon for gold (k value) and five other parameters. These parameters were percentage ash content, iodine number, methylene blue value, surface area, and pH respectively. Twenty four different proprietary brand activated carbon products were examined, the correlations being established by means of linear regression analysis. It was shown that a significant correlation only existed between k and pH value. This was interpreted in terms of the presence of oxide complexes on the activated carbon surface. Further test specifications as developed at the Anglo American Research Laboratories are also outlined with a view to the selection of activated carbons suitable for use in' a carbon-in-pulp operation. Methods for assessing both the capacity and the kinetic response of carbons for gold adsorption are presented, while the measurement of attrition resistance, particle size distribution and moisture and solubles content is also outlined. The measurement of the capacity constant for gold adsorption together with attrition resistance are considered to be necessary in the initial selection of a suitable carbon.

Jan 1, 1982

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

By Evan J. Owen, Virginia T. McLemore

There are tens of thousands of inactive mine features in 274 mining districts in New Mexico (including coal, uranium, metals, and industrial minerals districts). However, many of these mines have not been inventoried or prioritized for reclamation. Many of these mines have existing mine wastes, generated during mineral production, which could have potential for critical minerals, especially since the actual mineral production was generally for precious and base metals and not critical minerals. The purpose of this project is to characterize and estimate the critical mineral endowment of mine wastes and “beta-test” USGS sampling procedures. This project is important to the state of New Mexico because critical mineral resources must be identified before land exchanges, withdrawals or other land use decisions are made by government officials. Future mining of mine wastes that potentially contain critical minerals will directly benefit the economy of New Mexico. Possible re-mining of mine wastes could clean up these sites and pay for reclamation. Furthermore, this project will include training of younger, professional geologists and students in economic and reclamation geology by the PIs.

Feb 1, 2024

Detailed mapping in the Permian-Triassic clastic sediments of the Southern Alps delineates a number of strike-slip faults, both dextral and sinistral, associated with the major Alpine Fault to the west and displacing a tight array of fault blocks. Concurrent steeply plunging folds are deforming early major folds of probable Cretaceous age, and generating schist locally. To the east a major collapse zone has developed along the crest of a Cretaceous anticline, located over an ancient Permian submarine scarp, with a number of small normal faults. Further east, extensive Carboniferous to Triassic rocks of much the same appearance are exposed as horsts and grabens in a large possible extension zone through central and east Canterbury. This may have crept incrementally from Cretaceous from the offshore Bounty Trough to reach the eastern margins of the Southern Alps in the Pleistocene.

Jan 1, 1990

By T. Mudder, R. Cellan, R. Waterland, J. Whitlock, B. N. Nelson

The effectiveness of anaerobic in-situ biological treatment for the immobilization of selenium, molybdenum, and uranium in an alluvial aquifer was examined using long-term column tests. A series of organic substrate and nutrient combinations were tested to determine removal effectiveness, optimum supplement concentrations and ratios. Final column testing was conducted to determine the chemical stability of the treatment by-products/treatment compounds by dosing the columns continuously with elevated redox untreated alluvial groundwater.

Jan 1, 2002

By M Reisi, H Waterer, M Savelsbergh, F Engineer

The Hunter Valley Coal Chain Coordinator (HVCCC) Limited is the primary planning organisation responsible for the export of coal through the Port of Newcastle, Australia. HVCCC stakeholders include producers (mining companies), rail track owners, above rail operators, and terminal operators. The HVCCC is tasked with coordinating the activities of all the corresponding parts of the coal export supply chain so as to maximise the system efficiency. The HVCCC also has a forward looking planning role: with demand for coal expected to double in the next decade, strategic capacity planning is a core activity for the HVCCC. Optimisation and simulation models are key aids in such activity. They are used to suggest and evaluate infrastructure expansions and operating policy changes. These models require input data in the form of shipping stems, which are arrival streams of ships at the port, together with their cargo types and composition, and date and time of arrival.Although everyone is familiar with the expression ægarbage in equals garbage outÆ, relatively little research is dedicated to the issues surrounding input data generation. In this research we seek to redress this, and have developed a method for generating high quality shipping data. Shipping stems used as input should be realistic, reflecting key characteristics of historical patterns. They should accurately represent future demand scenarios. Yet they should also have controllable parameters that can be used to test what-if scenarios, such as are required by the HVCCC to answer questions about future infrastructure or operational plans.Here we review our process for achieving this, and give a case study analysing the effects of different shipping stems on the performance of the coal chain, as measured by a capacity assessment tool. The latter is an optimisation model that takes shipping stem and infrastructure data as input, and calculates key supply chain performance metrics. The potential benefits of alternative demand management strategies are analysed by measuring the performance of the coal chain given different shipping stems obtained via the stem generatorÆs controllable parameters.

Sep 26, 2011

By C. Hsu

Underground coal gasification (UCG) is becoming more popular as the reserves of good quality, mineable coal are starting to diminish, and yet the global energy demand from coal is still increasing. The purpose of this research project was to investigate cavity formation within a coal block due to the combustion reactions in the context of UCG. The cavity plays a pivotal role in the UCG process, as it is essentially the gasification reactor. Cavity formation in an in situ gasification process using the forward combustion linking method (FCL) had been investigated, and a laboratory model was created to simulate the process. The experiment was performed by drilling a U-shaped tunnel into a coal block, which was then combusted internally with air that was fed through an injection hole. A heating element (at approximately 500°C) was used to supply the required heat for combustion at the base of the injection well. The coal blocks were analysed using micro-focus X-ray tomography. The tomography results showed that the coal tended to crack along the bedding plane after a short duration of combustion, due to either the formation of clinker or the expansion of swelling vitrinite along the horizontal tunnel. The deposit was thicker at the base of the injection well compared to the base of the production well; this may have been caused by the turbulence of the air flow and the relatively high oxygen concentration at the base of the injection well. A comparison of the results with work by Daggupati et al. (2010) showed the same trend, despite the slightly different methodology applied.

Jan 1, 2014

By Mario A. Terceros H., K. Rainer Massarsch

"ABSTRACTThe Expander Body (EB) technology has been used successfully to increase the pile toe capacity of bored piles in loose to medium dense soil. An important advantage of the EB system is the ability to monitor the EB expansion process, which provides important information regarding soil strength and soil stiffness. This information, obtained for each installed pile, can be used to determine the actual shape and pile toe area. The expansion pressure can be used to design the pile base capacity.The Expander Body system has been recently improved by incorporating the possibility of post-grouting of the soil below the expanded pile toe. This improvement measure provides additional strength and stiffness to the pile toe and reduces pile settlement.The shaft bearing capacity of bored piles can be increased by using a soil displacement auger, which avoids soil decompression and increases lateral soil stress. This paper describes the principle of the EB system. During the past 20 years, a large number of EB piles have been installed in Bolivia and elsewhere, providing a sound database. Results from field loading tests are presented. A comprehensive study of test piles with and without EB base has been carried out which demonstrates the improvement effects that can be achieved by the EB pile system and the combination with the displacement auger pile method. A design concept for the EB pile system with the full displacement auger pile is presented. A high degree of quality control can be achieved by monitoring the entire pile installation process, including the displacement pile and the Expander Body.1. IntroductionIn many regions of South America, soil deposits consist often of predominantly loose to medium dense sands and silts, often with high groundwater table. In the Santa Cruz area in central Bolivia, such soils are frequently quaternary sediments, deposited by the river Piray. The city of Santa Cruz is located at the right bank of the river.The most common deep foundation method during the last 30 years has been cast in situ piles, augered and concreted under support of bentonite slurry. The design of such piles has been based on SPT results. However, SPT is often performed without quality control and the reliability of geotechnical data is therefore often poor. Traditional methods of pile installation with simple well drilling equipment of insufficient capacity are frequently used. Such methods lack basic requirements of quality control. Such piles have usually low toe resistance and work mainly by shaft resistance . Although the construction process and materials are cheap, the final product has variable and limited capacity. However, the most serious deficiency is that actually achieved pile capacity and pile settlement can be erratic and difficult to predict, leading to uncertainties with regard to actual foundation performance."

Jan 1, 2014

By Alix Thierart, Yann Rouillard, Bernard Catalano

Bessac's presence in Singapore started in 2014 with the construction of the Thomson metro line, which includes 18 miles of twin-bore tunnels and 22 stations split into 17 construction packages. Bessac joint venture was allotted the T219 lot. The works include the construction of a new 660-foot (200-meter) long transfer station, two parallel 19-foot (5.8 m) ID tunnels and a pedestrian underpass. The urban context and the very soft ground stratum imposed to utilize unusual tunneling techniques, from upgrading a slurry TBM to a high-density slurry TBM to launch with very low cover and canopy pipe roofing completed with a MTBM without retrieval shaft.

Jun 23, 2024

By T Ueda an, T Sasaoka, A Yabuki, H Shimada

The basic concept of auger mining is to extract coal beyond the economic limits of surface mining technology by drilling holes of an appropriate diameter size into the exposed seam of the highwall as deep as is technically, economically and operationally feasible. This method of mining is used at the final highwall of typical surface mining operations. This paper describes the auger mining systems and discusses the methods to increase the coal recovery in auger mining from a field trial in Australia.

Jan 1, 2003

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining community about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

May 1, 2008

By W. J. González

With the increasing demand for minerals and the decline in the quality of ore reserves, technologies to maximize recovery are critical to a mine?s economic success. Many mining waters exhibit the potential to form hardness-based inorganic scales, which inhibit effective mineral recovery. Often, a continuously-fed chemical deposit control program is implemented by the mine site to inhibit these scales. The use of retractable scale coupons is the current industry standard for monitoring these programs; however, a key drawback to their use is the limited, and sometimes untimely amount of information they provide. A proprietary fouling analyzer has been developed that can be used to continuously monitor the formation of inorganic scales in mining process streams. Consequently, it can be used to continually, and more effectively, communicate the efficacy of an antiscalant program, thereby providing the ability to compare different scale control programs and to optimize their feedrates. Case studies presented validate the applicability of this technology to help optimize mineral recovery.

Feb 23, 2014

By Robert J. McCarthy

Many technologies have been adopted over the last half century for the haulage of material from open pit mining operations. Some of the technologies utilized include rail, off-highway trucks, conveyors, and slurry pipelines - each having its unique application and benefits. Over time, truck haulage has become the primary means of surface mine material movement, though recently it has been plagued by problems of tire shortages, high diesel fuel costs, labour shortages, and carbon emissions. This paper focuses on In-Pit Crushing and Conveying (IPCC) as a competitor to truck haulage which has the potential to solve many of these problems. An overview of the available technology is presented along with measures required to overcome perceptional if not physical barriers to implementing this technology in modern open pit mines.

May 1, 2011

The four major contracts for the construction of Museum Station are: 1) Installation of Soldier Piles, 2) Structural Contract including the temporary support, 3) Architectural Finishes which include Electrical and Mechanical Services and 4) Supply and Installation of lifts and escalators. Specific areas of interest include the fabrication, installation and removal of temporary support steelwork, the monitoring of ground loading, and the interface between the structure and. the temporary support. The information collated during construction confirmed the design assumptions and criteria. No major changes'were required in the design of the construction methods. The open cut excavation and construction of this major structure in an inner city area was significant by any standard and was successfully completed with minimum disruption to the public and without damage to adjoining or surrounding property.

Jan 1, 1981

By H. De Cizancourt

France.—Pechelbronn remains about the only producing field, 41 per cent of the 1937 output of 496,525 bbl. being mined by shaft and 59 per cent produced from pumping wells. At present Gabian has only a very small production. During 1937 there was no private undertaking for petroleum research. Only the Office National des Combustibles Liquides has done any drilling, unsuccessfully, at Pezenas and Frangy-Chilly. Algeria.—No new research has been made and Tliouanet, a small acreage pool that has been declining for several years, gave only 2193 bbl. in 1937. Morocco.—The SociCt6 Chhrifienne des Petroles continues active work. First tests of production made on the Jurassic structures of the Tselfat and Bou Draa must be mentioned for 1937. In connection with these tests, which have yielded 16,495 bbl., 14 new wells have been located

Jan 1, 1938

The seemingly insatiable world demand for mineral and energy products is continuously pushing out the frontiers of exploration and development in countries around the Pacific Rim.

Jan 1, 1990