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By Nageswararao K

A series of tests was carried out on one of the rock-pebble milling circuits treating complex nickel ores at Kambalda Nickel Operations of Western Mining Corporation. A mathematical model to describe the behaviour of a 508 mm hydrocyclone was developed from the data.A "flat" reduced efficiency curve was observed for the system. This was attributed to a marked difference in the specific gravity of different size fractions of the feed. A modified approach in describing the shape or the reduced efficiency curve resulted in accurate prediction of the hydrocyclone performance.

Jan 1, 1981

By R. E. McElvain

"Hydraulic transportation of solids in suspension with water or other carriers, such as oil is becoming more practical as economic situations develop with respect to the railroads and other carriers. Of significant importance, is also the increased size of the major operations and the total impact of larg- er tonnages and more critical sources of supply.There are several means of imparting energy into the solids and directing the material down a pipeline, but the centrifugal pump is emerging as the most practical piece of equipment when considering relatively large flows and recent development. We can now handle relatively high densities without interruptions. This provides the mining and transportation fields a more economical means of lifting and transporting coal and other mineral products.Equipment & MethodsWarman International has developed several methods of alternate PDP against high heads. We have, at least for the present time, shelved our pump which uses clear water to slurry method and have placed our major emphasis on the full development of the centrifugal pump. I personally see several similarities on the alternate reciprocating devices as compared with the steam piston type engine versus steam turbines. The centrifugal pump comes into its most advantageous position at about 2000 GPM and can also show advantages by means of increased mobility, when driving tunnels and in other difficult operations when considering the total economic results. We now have some interesting d<:ta on one 5 mile raw silica sand line designed for pumping at 200-400 tons per h:mr. This is a separate subject on a ""simplified approach to slurry transport"" and paper has been prepared for the Hydrotransport 5 proceedings in Germany this Spring. Reference 1 may be of interest to those who want to delve into the subject further, and I also have some advance copies of this paper."

Jan 1, 1978

By M. S. Klima, A. Simard, M. L. Turek

Laboratory testing was carried out to evaluate several devices for recovering clean coal from bituminous coal refuse material. The bulk of the testing focused on using a dense-medium cyclone to process -0.6-mm refuse material. A hindered-settling column and a spiral concentrator were also used to process 1.2x0.15-mm material. Product yields and ash contents were obtained for all tests, while partition curves were generated for selected tests from which the characteristic performance parameters (relative density of separation and probable error) were determined. The results indicated that the dense-medium cyclone was capable of cleaning down to 0.037 mm, while the other devices were effective to 0.15 mm.

Jan 1, 2002

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate (AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool.

Feb 1, 2020

By A. M. Ramadan

The composition of phosphate rocks, mainly used in manufacturing fertilizers, varies among deposits; therefore, phosphate rocks from different sources are expected to behave differently in acidulation processes. This paper examines the effect of preconcentration of phosphate ore from El-Sebaiya East, Egypt, using flotation on uranium leaching. A high-grade ore sample (27.3% P2O5, 168 mg/kg U) supplied by the Al-Nasr Mining Company, was subjected to reverse single-stage flotation to separate carbonate from the phosphate sample. Subsequently, P2O5 and U concentrations were 32.2% (92.1% recovery) and 225 mg/kg, respectively. After the leach process, the U concentration in the liquor was 319 mg/L.

Jan 1, 2014

By H. A. Bilgin, G. G. U. Aldas

"Ground vibration is the natural result of the blasting process. Many empirical formulae and methodologies including analysis of travel path effects have been developed. The scaled distance, which is the most popular approach for the calculation of the attenuation of particle velocity in the ground, has led to significant advances in the prediction of particle velocity when both explosive charge and distance vary. However, this approach does not consider the effect of ground anisotropy and existence of structural geological features on ground vibration. Therefore, in this study, the effects of these rock mass properties on types, amplitudes, and frequencies of ground vibration waves at four surface mines are examined. The results, which were implemented at Kangal coal mine, Bastas quarry and Kíbrís quarry, provided guidance for the extensive study at Orhaneli surface coal mine.As a result of the study, the authors came to the conclusion that vibration amplitudes change depending on the ground on which sensors were deployed and the conditions depending on whether measurements were done near major structural geological features. It was determined that the vibration amplitudes, measured at equal distances from the source but in different directions, change because of the propagation velocity anisotropy. Besides the change of wave type due to the kind of ground at the measurement location, it was determined that vibration anomolies were due to structural features."

Jan 1, 2004

By Sung. Hyejin, Kyoungkeun Yoo, Oh-hyeok Kown

The sediments near coasts and ports in Korea have been found to be contaminated with heavy metals and organic matters. So far the sediments have been dumped to landfill sites or ocean. However, the number of available landfill sites is decreasing and ocean disposal of wastes was strictly prohibited. Although physical separation processes have been found to be useful for the remediation of contaminated soil with heavy metals, because the sediments consist of fine particles, it is difficult to remove heavy metal component by physical separation processes. Furthermore, the sediments contain organic matter, so there is a concern about strong stink during the sediment treatment. The present study is aimed to develop the treatment process for removing heavy metals and organic matter from the contaminated sediments. The heavy metals and organic matter were oxidized and dissolved by electro-generated chlorine, and the chlorine used is regenerated and circulated in the leaching process. This system has economic and environmental advantages to reduce the wastewater and the oxidant consumption. The leaching results show that the metal removal efficiency increased to more than 99%, and more than 50% of organic matter was decomposed.

Jan 1, 2014

By M. M. Gadde

Recent regulatory changes in the United States make it mandatory to conduct structural analysis of coal mine seals used to isolate abandoned workings from active mining areas. Different loading criteria are available for seal design depending on whether gob composition is actively monitored and maintained or not and whether the gob conditions lead to deflagration or detonation type loading. Since the loads involved in seal designs are dynamic in nature, the structural analysis must be made using dynamic stress analysis techniques. However, because of the significant complexities involved in conducting dynamic analyses, some designers use approximate simplified techniques to address the design problem. In this paper two such simplified methods are critically evaluated for their suitability to design coal mine seals. The benefits and limitations of the simplified methods are also outlined. Some comparisons are made to show the differences between sophisticated three dimensional dynamic analyses and the simplified methods and to delineate the problems associated with the latter approaches.

Jan 1, 2009

By Sam McNary

The U.S. Bureau of Mines used the East Fork Pine Creek watershed to conduct a pilot study for an inactive and abandoned mine lands inventory, during which techniques and methodologies would be developed for subsequent inventories. A total of 177 waste dump samples, 191 mill tailings samples, and 36 stream sediment samples were collected. Water samples were collected from 18 sample sites during five sampling events. Waste dump, tailings, and stream sediment samples were analyzed for antimony, arsenic, cadmium, copper, iron, lead, mercury, and zinc. Results indicate a multidisciplinary approach is necessary: disciplines should include geology, geostatistis, geochemistry, geophysics, biology, hydrology, and remote sensing; small prospects do not generally contribute to watershed contamination, major mine and mill sites may contribute metal enriched sediment of metal enriched water; speciation studies and bioavailability studies are important.

Jan 1, 1995

By Thomas M. Barczak

The 1990s brought an unprecedented increase in the development of innovative technologies to provide more effective and easier-to-install roof support in underground mines. To facilitate the application of these technologies in improving mine safety, the National Institute for Occupational Safety and Health (NIOSH) developed the Support Technology Optimization Program (STOP). STOP is a Windows-based software program that provides mine operators with a simple and practical tool to make engineering decisions about the selection and placement of these various roof support technologies. The program includes a complete database of the support characteristics and loading profiles obtained through safety performance testing of these supports at the NIOSH Safety Structures Testing Laboratory. A support design criterion in the form of the required support load density at a specified convergence can be established from four options: (1) a database of measured ground reaction obtained from various mines or ground behavior information input by the user,(2) load requirements based on a detached roof block or rock failure height, (3) criteria based on the current roof support system, and/or (4) arbitrary criteria set by the user. Using these design criteria, the program will determine the installation requirements for a particular support technology that will provide the necessary support load density and convergence control. Optimization routines are also available to determine the most efficient support design for a user-specified support installation. In addition to these performance measures, STOP can be used to compare material handling requirements and installation costs. Comparisons among the various support technologies are easily made, including a graphical analysis of relevant support parameters. This paper describes STOP and its application to optimizing standing secondary roof support systems.

Jan 10, 2000

Traditional loading systems have relied for many years on wheel and track loaders, power shovels, conveyor belts, and more recently, hydraulic front shovels. Each has certain advantages and disadvantages, depending largely on job conditions. Hydraulic backhoes were introduced several years ago as still another truck loading option. At first, buckets were small and backhoe use was limited to small earthmoving projects. Now, as backhoes are equipped with shorter sticks and bigger buckets to move larger quantities of earth. The "mass excavation" concept offers an excellent truck loading option in many situations. System Development and Advantages Mass excavation was first used successfully by contractors in site development and highway construction, loading both on-highway and off-highway trucks. Operators were able to take advantage of the excavator&apos;s ability to work in poor underfoot conditions and dig in tough materials. The technique was first applied to mining in the kaolin mines of central Georgia. Kaolin, one of the world&apos;s most abundant minerals, is used to make paper, paint, ceramics, rubber, plastics, and many other products. Since kaolin clay is slippery when wet, load-out with wheel loaders is very inefficient. Also, kaolin is found in very spotty deposits due to the weathering process involved in its formation. Consequently, draglines are also impractical for kaolin mining since they don&apos;t have the mobility to move between clay deposits. In response to these mining conditions and kaolin characteristics, mines began using excavators in mass excavation as early as 1976. They have developed a system that takes advantage of the excavator&apos;s •high penetration and breakout force in tight materials; •fast-cycling hydraulics; •ability to work in poor underfoot conditions; and •mobility in comparison to draglines. This loading method has been successful in Georgia&apos;s kaolin mines and now can be applied to other mining operations as well. The excavator&apos;s ability to carefully dig spotty ore deposits is an asset at uranium mining operations. Any mine can take ad-

Jan 3, 1982

By Catherine Cai

A granular sorbent, prepared by gel-coating polyethyleneimine (PEI) on high surface area silica followed by crosslinking with a low-molecular weight diepoxide, has significantly higher uranium capacity, greater salt tolerance, and faster kinetics than the commercial resin Dowex 21K. Though having lower U(VI)/Fe(III) selectivity than Dowex 21K, the gel-coated PEI affords much higher sorptions of both U(VI) and Fe(III) and also their separation by selective stripping with acid.

Jan 1, 1999

By Gerke Gilian, Pretz Thomas, Pehlken Alexandra

"The evaluation of health hazards within the treatment of mineral and waste materials is gaining more and more importance in industrial countries. The need to control occupational safety has been recognised, and regulations which describe general protective measurements for personnel provide a tool to protect their health. It is the aim of the paper to give an outlook for practical approaches to risk assessment and to present measures for exposure reduction in accordance with the state of the art in Germany.Both the treatment of minerals and of waste materials are described in relation to the risk assessment. The method of evaluating health hazards in the two industries is similar and therefore both examples are presented next to each other.The example presented in the paper is the German “Biostoffverordnung” (the regulation for biological materials) which is important for the waste treatment industry. All kinds of waste treatment facilities (like composting facilities, waste dumps, sorting facilities for packaging materials) are obliged to carry out an assessment of health hazards for a variety of working areas and working places. The possible safety requirements deriving from this regulation are presented and discussed under the aspect of biological hazards.All over the world each country has different guidelines and regulations but all have one target in common – to protect the employees. This can be achieved through a good management system of occupational health and safety. Therefore the health hazards have to be known and assessed.Principles of the assessment of health hazards are described through:Data collection on siteData evaluationAssessment of health hazardsDocumentation"

Jan 1, 2003

By E. V. Konoplev

Russia is one of the largest manufacturers of potash fertilizers in the world. Processing of potash ores basically is carried out by a flotation way. Potash ores of the Verhnekamsky potash deposit contain sylvite (KCl), halite (NaCl) and water insoluble impurity (up to 8 %), presented silicate- carbonate minerals, easily slimed by ore crushing in rod mills. Ore of some deposit sites, developed by ?Uralkali? Co, contains a significant amount of a carnal-lite (KCl.MgCl2.6H2O). Work practice of flotation potash plants has shown, that increase of car-nallite content in ore leads to increase magnesium ion content in a circulated plant brine (saturated salt solution of potassium and sodium chlorides-sylvite brine) and to deterioration of indicators of ore processing. In the Paper we present results of researches of floatability of various size sylvite and influences silicate-carbonate slimes on sylvite flotation in brines with the various magnesium chloride content. It is established, that with increase magnesium chloride content in the brine mainly decreases the flotation of coarse sylvite and amplifies adverse effect of silicate-carbonate slimes on sylvite flotation. In this connection deterioration of potash ore flotation is caused not only decrease sylvite floatability but also strengthening adverse action of water insoluble impurity on potash flotation. It is shown that the application of frothing agents, which render the stronger dispersive action on the colloidal-micellar structures of amine in the salt solution increases the absorption of collector on the sylvite and improves the flotation of sylvite into magnesium the containing salt solutions. The application of an organic depressor to the greatest degree of decreasing the absorption amine on the slimes and to the smallest degree possessing anionic properties proves to be most effective with the flotation carnallite of the containing potassium ores. It is offered the application the frother on a basis of glycol ethers and organic depressor on a basis of urea-formaldehyde resin. Results of industrial tests developed reagent modes for flotation treatment of ores with the raised carnallite content (to 6 %) on ?Uralkali? Co plant have shown that their application has allowed to receive equivalent indicators potash flotations at change of magnesium chloride content in the brine from 0.7 % up to 2.4 % .

Jan 1, 2014

By J. O. Winget

Phosphonic acid and iminodiacetic acid chelating resins were investigated to assess their potential as selective ion exchangers for separating lanthanide elements and yttrium . The affinity of phosphonic acid resin for lanthanides increases with increasing atomic number , and that of iminodiacetic acid resin for lanthanides increases with atomic number to a maximum for element 62 and then declines with atomic number throughout the remainder of the series . Elution sequences of the elements with mineral acid eluants corresponded favorably with equilibrium data , whereas the elution sequence obtained with chelating eluants was proportional to the relative values of the stability constants of the chelating agents with the lanthanides . Separation of lanthanide mixtures into groups of light and heavy elements with iminodiacetic acid resin appears feasible .

Jan 1, 1964

By J. H. Zietsman, M. W. Erwee, P. J. A. Bezuidenhout, Q. G. Reynolds

"Pyrometallurgical furnaces are tapped through tap-holes that are opened with drills and oxygen lances. The lance is often used on its own or as the last step of opening the tap-hole. Interaction of oxygen with molten material inside the tap-hole can occur, and is a phenomenon that is not well understood. As part of a study that focuses on the effect of lancing on flow inside and around the furnace tap-hole, a cold-model validation was done. The validation study focuses on validating the MULTIPHASEINTERFOAM multiphase flow solver in OpenFOAM® for the problem involved. The sensitivity of the model to different materials properties (viscosity and density in particular) is presented with both cold models and the results from flow simulations in OpenFOAM®. IntroductionMany pyrometallurgical operations are carried out in furnaces where molten material accumulates continuously. Once enough material has accumulated and is ready to be removed from the furnace, material is tapped through one or more tap-holes in the furnace. Tap-holes differ significantly in both geometry and materials of construction, depending on the process involved – examples of different types of tap-hole configurations can be found in, for example, Nelson and Hundermark (2014). Tapholes all share one common feature: they are high, wear areas of the furnace. Molten material at high temperature flows through these areas, after which the tap-hole is sealed, usually using tap-hole clay. The purpose of the tap-hole clay is to harden inside the tap-hole and seal it until the next tap.Once ready to tap, a pneumatic drill and/or oxygen lance is used to open the tap-hole. The extent of lancing a furnace tap-hole depends strongly on the type of furnace. In, for example, many blast furnace operations lancing is limited as much as possible, and done only if drilling was not effective. In other operations, such as on small-scale pilot furnaces with short tap-holes, only lancing is used to open the tap-hole."

Jun 1, 2019

By G A. Wellwood

What do all iron ore mines have in common? Perfect production days! Yes, those harmonious 24-hour periods when the stars align and the daily output number rockets past the long-term average to hit new heights. While perfect days are always welcome, the focusing question iswas that just a ‘flash in the pan’ (due to a special cause) or an indication of the process’s capability (with clues to the common causes) which, if addressed, could make every day perfect? In the context of today’s operating environment, with the need to maximise productivity at minimum cost, it’s an important question.Investigations reveal that the throughput difference between a perfect production day and the average is often in the order of 40 per cent, and that bulk solids handling (BSH) system deficiencies are the largest (&gt;50 per cent) class of lost opportunity. Root causes for underperformance of elements in BSH systems can often be traced back to the detailed design and even study-stage oversights. Essentially baked into the fabricated plant, operations are effectively forced to accept them at the point of practical completion and then deal with the consequences for the life of the mine. Subsequent normalisation of these defects in the planning process reduces visibility and hence the impetus for long-term solutions in favour of lower targets and quick fixes to keep the show on the road. On an industry wide basis the design processes and assumptions responsible for BSH system underperformance become enshrined as common practice and hence repeated across sites and organisations.In addition to making the case for action, practical steps that can be taken to help realise the significant productivity prize and avoid the problems in first place are provided.CITATION:Wellwood, G A, 2017. One perfect (production) day – a bulk solids handling perspective, in Proceedings Iron Ore 2017, pp 443–452 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Tariq B. Hamid

Deep excavation is commonly associated with construction of different deep below-grade structural elements (e.g., basement walls and slabs, tunnels, retaining walls, tanks, utilities, etc.) Deep Excavation Retaining Systems (DERS) are required when open cuts with safe slopes are not possible. Careful analysis, design, and planning of the DERS are required to provide safe below-grade construction and secure nearby structures from damaging effects that may result from the deep excavation. Selection and design of temporary or permanent DERS (e.g., soldier pile and lagging, sheet piling walls, secant pile walls, tie backs, etc.) can have significant impact on time, cost, and performance. In order to design DERS using conventional methods, it is necessary to obtain shear strength parameters, angle of internal friction (ø), and cohesion (c), of retained soils. Residual shear strength parameters (ø&apos;res, c&apos;res) obtained from drained direct shear tests and triaxial tests on saturated samples have been commonly used in practice for the analysis and design of DERS. However, there are cases where ground water table remains at or below the base of excavation during the design lifetime of DERS. In such cases, the soil above the ground water table is in an unsaturated state. Therefore, it is important to account for the unsaturated conditions of soils in order to optimize the design of DERS. This paper is focused on implementing the basic concepts of unsaturated soils mechanics including matric suction and soils-water characteristic curve (SWCC) to estimate design shear strength parameters of unsaturated soils (i.e., ø°, c&apos;, and ø&apos;) for the design of a cantilever sheet pile walls, a typical case of study of the DERS. The results of this study indicate that the determination of unsaturated soil strength shear strength parameters is simple. In addition, using unsaturated soil mechanics theories has an outstanding impact on the design of retaining systems.

Jan 1, 2006

By J. E. Shelton

Flotation tests are described on samples of two lowgrade nickeliferous ores of Oregon and Washington. The sample from the Congress mine, Ferry County, Wash., contained 1.2 percent Ni, occurring chiefly as millerite. The sample from the Shamrock mine, Jackson County, Oreg., contained 2.20 percent Ni and 0.78 percent Cu occurring chiefly as pentlandite, nickeliferous pyrrhotite, and chalcopyrite. The millerite in the Congress ore was concentrated by flotatioin with aulfydric collectors in a series of locked tests to recover 73 percent of the nickel as a 7 percent bulk concentrate. By successively regrinding and floating the bulk concentrate, it was further concentrated to 12.4 percent Ni at a recovery of 59 percent and 21.8 percent Ni at a recovery of 50 percent. Attempts at selective concentration of the copper-nickel Shamrock ore were only partly successful because of the intimate association of pentlandite and chalcopyrite. The nickel concentrate, which contained 86 percent of the nickel, had an analysis of 4.42 percent Ni and 1.03 percent Cu. The copper concentrate had an analysis of 18.8 percent Cu and 1.96 percent Ni and contained 48.5 percent of the copper. A bulk sulfide concentrate contained 92 percent of the copper and 01 per¬cent of the nickel and had an analysis of 4.17 percent Ni and 1.63 percent Cu.

Jan 1, 1956

By Ronald E. Heuer, Debra L. Virgens

INTRODUCTION Behavior of clay soils in response to tunneling is reasonably well understood by reference to the tunnel stability factor NT = Pz/su (Peck, 1969; Heuer, 1974). With this analysis tool, care must be taken to use a value of clay shear strength which represents the actual mass strength, considering such factors as slickensided fissures often found in stiff and hard clays. Behavior of clean sand and gravel soils is also reasonably well understood. Above the water table these soils must be assumed to act as running ground unless they are known to have significant cementation or have a very dense and angular interlocked grain structure. Below the water table they must be tunneled using some form of groundwater control such as dewatering, grouting, freezing, or internal fluid pressure in the tunnel such as compressed air or a slurry tunneling machine. The internal fluid pressure must approximately balance the external water head. Without such precautions these soils behave as flowing ground and may yield large volumes of water flow into the tunnel. A wide range of very fine sand, silty sand, cohesionless silt, and clayey sand soils exist in nature in a variety of geologic environments. The behavior of these soils in response to tunneling, and guidelines for anticipating their behavior, are not well described in the literature. Because of their content of fine particles, these materials may behave as if they initially have appreciable cohesion and moderate to low permeability. They may exhibit significant standup time, and require tunnel internal fluid pressure (compressed air or slurry pressure) less than the full external water head. It is important to be able to estimate the behavior of these soils when planning construction methods. For example, if the external water pressure is 140 kPa (20 psi), but soil stability at the tunnel face can be achieved as a compressed air pressure of 80 kPa (12 psi), a large cost savings may result.

Jan 1, 1987