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By Dalton. J. L., H. P. Dibbs

An account is given of investigations into the application of two neutron methods to the on-line analysis of slurries. One deals with the application of the neutron moisture gauge principle to the determination of the water content of iron oxide slurries, and the other with the application of gamma radiation from thermal-neutron-capture to the determination of the composition of aqueous slurries of iron oxide, copper oxide, zinc oxide and sulphur. Linear relationships were found between the composition of the slurry and the neutron count-rate in the first study, and between the slurry composition and the prompt-gamma-ray count-rate in the second study. A mathematical relationship has also been developed which relates changes in the prompt-gamma-ray counts from hydrogen to changes in slurry composition.

Jan 1, 1973

1.Assessment of methane content in coal. Given a naturally low methane content in 11 Coal Seam and the fact that the areas of the 11 Seam adjacent to the tunnelway were degassing for a very, very long time due to previous development and mining, it is conservatively estimated that the remaining in -situ methane is less than 0.5m3/tonne. 2. Continuous miner cutting rate based on the past practice. The best loading rate recorded at the past operations of Smoky River Coal was 45 seconds for a 8 tonnes shuttle car. Using these records, the maximum peak loading rate potential at the face is calculated at 0.178 tonnes per one second or 10.67 tonnes per one minute. 3. Methane release at the face. ?The actual face methane liberation, conservatively assumed at 40% of the total in situ content: 0.20 m3/tonne ?The peak cutting rate: 0.178 t/sec ?The maximum (peak) face methane release: 0.20*0.178 = 0.036 m3/sec

May 1, 2003

By Adriaan de Villiers

Many conventional structural analysis and design methods in current use are not appropriate for the mining industry. Two major reasons for this are that: • The economic life of a particular mine is limited, and • Much of the equipment and machinery used by the mining industry operates at relatively low speeds. Both of these factors can have significant cost implications if they are not properly accounted for during plant design. In particular, the often used practice of mitigating excessive vibration by adding mass to machinery supports is not only expensive but may worsen the vibration effects. Some of these problems, such as increased wear and tear, are not always easy to trace back to inappropriate design. This article focuses on vibration related issues and demonstrates that the mining sector has unique problems requiring unique solutions. Vibration: the basics Historic developments leading to current vibration design practices provide the key to why such practices are often inappropriate for the mining industry. To understand this, it is necessary to introduce some basic vibration theory. Consider a simply supported beam or foundation on which a vibrating machine is mounted. For analysis of the system's dynamic response, it may be viewed as a mass attached to a spring and a damper, such as the shock absorber of a car.

Jan 1, 1992

By C J. de Beer

The Kwaggashoek East pit is one of the four production areas of Thabazimbi Iron Ore Mine. The Kwaggashoek East Open pit mines through the abandoned sublevel caving operations of the Kwaggashoek East underground workings. A risk assessment indicated that the primary risk is the occurrence of surface subsidence. Based on local knowledge, a hypothesis, that most of the cavities were filled with broken rock as a result of roof collapse and bulking of failed material was formulated. To test the hypothesis a number of geophysical methods as well as probe drilling was utilized. The results of the resistivity, gravity and ground penetrating radar surveys were inconclusive in determining the position of voids. Either there were no voids present or the resolution of the surveys was not high enough to pick it up. It is accepted that only small voids remained, and that the supported roof hypothesis is valid. As a precautionary measure all the production blast holes within the caving area were over-drilled by forty percent. This would collapse the roof of any small voids or tunnels immediately below the block. This operation proved to be successful as two of the three underground levels have been mined out with no subsidence occurring in the pit floor.

Jan 1, 2006

By Lawrie D. C

Finely ground beryl was decomposed by mixing with ground limestone and soda ash and heating at 900°C for 4-6 hr. The sintered mater:al was then crushed and leached by boiling under reflux with 5N sulphuric acid for up to 4 hr. The liquor containing Be, AI, Fe and other elements as sulphates, was separated from the residue which consisted mainly of silica and gypsum, either by filtration or bydecantation washing.The clarified leach liquor was first treated to remove Fe+++ by contacting with a primary amine-kerosene solution in 2 countercurrent stages. The iron free liquor was then passed to a 4-stage counter-current extraction unit where it was contacted with O·5M di- (2 ethyl hexyl) phosphoric acid (EHPA) in kerosene. Under the operating conditions, 99 per cent of the Be and 7 per cent of the Al was extracted.The Be and Al were stripped from the organic phase by sodium hydroxide solution of suitable concentration to form soluble "beryllate" and "aluminate" respectively. Most of the Be was subsequently precipitatedas Be(OH)2 by heating the alkaline solution to 90°C, the Al remaining in solution. After filtration and washing, the Be(OH)2 could be ignited directly to BeO at about 1000°C or used as a feed to further purification stages if required.A small counter-current extraction unit was operated continuously using liquor derived from the sintering and leaching stages. Dataobtained in batch laboratory tests were confirmed. A product obtained by ignition of the washed "beryllate" precipitate contained more than 99 per cent BeO.INTRODUCTIONIn 1958 an investigation was commenced into the recovery of beryllium oxide from beryl, as part of a programme to utilize mineral resources of South Australia. A survey of the literature indicated that little work had been done on direct solvent extraction of beryllium from aqueous liquors, so it was decided to apply the experience gained in this field in uranium processing to the current problem.Preliminary extraction tests on solutions of beryllium...

Jan 1, 1965

By Horst Pöchhacker

The largest structure along the Tauern highway section between Salzburg and Villach is the 6.4-km-long Tauern Tunnel. The major geotechnical problems that came up surprisingly while driving the headings of that tunnel and their successful solution form the content of this article. A detailed discussion is presented of the special construction methods developed by systematic application of the principles of the New Austrian Tunneling Method with which even very heavily squeezing ground with large excavation areas can be mastered reliably and economically.

Jan 1, 1976

By M. Soleymani Shishvan

"Continuous mining systems containing multiple excavators producing multiple products of raw materials are highly complex, exhibiting strong interdependency between constituents. Furthermore, random variables govern the system, which causes uncertainty in the supply of raw materials: uncertainty in knowledge about the reserve, the quantity demanded by the customers, and the breakdown of equipment. This paper presents a stochastic-based mine process simulator capturing different sources of uncertainties. It aims to quantify the effect of geological uncertainty and its impacts on the ability to deliver contractually defined quantities and qualities of coal, and on the system efficiency in terms of utilization of major equipment. Two different areas of research are combined: geostatistical simulation for capturing geological uncertainty, and stochastic process simulation to predict the performance and reliability of a large continuous mining system.The process of modelling and simulation in this specific production environment is discussed in detail. Problem specification and a new integrated simulation approach are presented. A case study in a large coal mine is used to demonstrate the impacts and evaluate the results in terms of reaching optimal production control decisions to increase average equipment utilization and control coal quality and quantity. The new approach is expected to lead to more robust decisions, improved efficiencies, and better coal quality management.IntroductionContinuous coal mining systems containing multiple excavators producing multiple products of raw materials are highly complex and exhibit strong interdependencies between constituents. A network of conveyor belts is used for transportation of the extracted materials to different waste dumps or the coal stockpile.Optimal decision-making in short-term planning and production control are impacted mainly by geological uncertainty associated with incomplete knowledge of the coal deposit represented in the reserve block model. These uncertainties cause deviations from expected process performance. For more robust decision-making, understanding the impacts of these stochastic elements plays a key role."

Jan 1, 2016

By Eugene McAuliffe

AS anthracite is no longer used to a marked extent by the rail- ways of the United States (1,513,000 tons in 1933), that portion of the mining industry engaged in the production of bituminous coal is, and will continue to be, the one chiefly concerned with the future use of its product by the railways. In a period such as the present, when all enter- prise is unsettled, when fundamental principles of industrial management and control are being swept aside or else changed overnight, it is difficult to predict what will happen. The relation between the total production of bituminous coal and the volume consumed by the steam rail- ways of the United States, Classes I,

Jan 1, 1936

By A R. Sale

This paper highlights two aspects of the mineral sands industry in Australia: the development of the industry from approximately 1870 through to 1980, and the author’s experience in the industry from 1966 to date.The first real heavy mineral (HM) mining in Australia started in 1870 with the mining of heavy mineral slicks on the beaches along the east coast of Australia. The real potential of Australian heavy minerals was however only realised in the 1920s with the first production of a heavy mineral concentrate that was shipped to Canada for processing. Post WW 11 and the Korean War, Australia was the largest producer of mineral sands products in the world as well as a significant developer of associated separation equipment and technology. The number of producing companies in the east coast peaked at 33 in 1957, was reduced to ten by 1965, and subsequently further reduced to five in 1980 as a result of potential mining areas being declared National Parks or Conservation Reserves. Today there is one company, Unimin Australia Pty Ltd (formally Consolidated Rutile Ltd) operating on the east coast. In contrast there were three companies on the west coast in 1965, four companies in 1980, and four companies today (albeit not the same companies).There have been considerable ups and downs for the industry in Australia, however world wide it was renowned in the past as being an industry that attracted numerous interesting and innovative characters that played a major role in developing it into the vibrant industry that it is today. This, given the current climate, is predicted to continue into the future.The author has been continuously involved in the industry for over 45 years from 1966, initially as an electrician at Consolidated Rutile Ltd culminating in the role of General Manager/President of Iluka Resources Limited USA, prior to his retirement in 2009. His exposure has been world wide and has covered all aspects of the industry but in the main focused on project development and operational areas. During this time there have been significant technological advances, yet to some extent the basic principles have not changed at all. Some of the most noteworthy advances include the development of the Wright Spiral in 1977, the development of the Reading High Intensity Wet Magnet (WHIMS), the rare earth magnets, the CRL floating thickener and the improvement of analytical techniques. From a safety, health and environmental perspective there has been significant advances that the industry has much to be proud of. These include wetland restoration both in Australia and in the US, the restoration of farmland in Virginia and Capel, and the re-establishment of native species, for example at Eneabba and Richards Bay to name but a few.

Oct 5, 2011

By G. E. Agar, W. B. Kipkie, V. K. Drylie

"This paper describes mineral processing test work on drill core samples from an ilmenite deposit in Terrebonne County just north of Montreal.Mineralogical examination showed that the intimate associa¬tion between ilmenite and hematite precluded their separation. The maximum concentrate grade was therefore limited to 22.9% Ti. Liberation of gangue from the hemo-ilmenite grains occurred around 400 µm, a size which proved to be too coarse for recovery by flotation.Other physical separation techniques, such as elec¬trodynamic, magnetic and jigging, were tried in order to take advantage of the relatively coarse liberation size. An all-flotation procedure and a combination of jigging and flotation yielded similar separations.IntroductionInco Metals Company, through its subsidiary Canico, optioned an ilmenite deposit in Terrebonne County, just north of Montreal, and conducted a drilling campaign to confirm previous geological assessments of the deposit and to provide core samples for mineralogical study. Parts of these core samples were used for mineral processing studies, which will be described in this report. The objective was to identify suitable upgrading procedures, to determine the optimum combination of concentrate grade and recovery, and to provide suitable batches of concentrate for further treatment."

Jan 1, 1980

By M. I. Al-Wakeel

Nile sediment was collected as a waste from one of the water treatment plants in Cairo, and subjected to petrographical investigation and granulometric, chemical, and mineralogical analyses. It was expected to find diatomite in that sediment but it was a surprise to find that the diatomite content amounted to about 52.01% by volume in addition to quartz, orthoclase and clay minerals. The latter are represented by montmorillonite and illite minerals. The sediment is light gray in color, soft and has low density and high surface area, such density and surface area generally decrease with temperature. The sediment absorbs 317% of its weight in water. The diatomite skeletons are the main factor responsible for its high porosity producing microporosity and low density, and these particles are concentrated in the very fine silt size fraction (11x2µm). The common diatoms in such sediment include Cyclotella ocellata Pant, and Melosira granulata (Ehr.) Ralfs. It seems that this Nile diatomaceous sediment has many advantages over the fossil diatomite, such as Fayium diatomite in Egypt, with the absence of carbonate minerals that require grinding and calcination those cause destruction of the cellular structure and energy consumption. This Nile diatomaceous sediment can be processed using sequential classification to obtain diatomite concentrate of 88.8% grade at 90.6% recovery, and a middling product of 19.4% grade and 5.8% recovery. The suggested flow sheet is quite simple to produce diatomite product for different industries at a low cost. The unusual particulate structure and chemical inertness make diatomite an ideal mineral to be used as functional filler in a wide range of industries, and as catalyst carriers and insulating material. Key words: Egypt, Nile sediment, Diatomite, Beneficiation, Sedimentation, Classification.

Jan 1, 2008

By Andrea Francioso, Roberto Folchi

In order to comply with the latest European Highway Standards, the highway Salerno - Reggio Calabria, in southern Italy, had do be widened and upgraded to reduce its vulnerability to earthquakes. Reinforced concrete viaducts, no longer needed for the new road, had to be demolished. Many bridges still to be used for the highway required refurbishment due to 50 years of wind, frost and salt corrosion. This re-furbishment and new construction had to be carried out simultaneously. To keep the highway open dur-ing the renewal process, all traffic was directed to one side of the road. Demolition was conducted ex-tremely close to operational roadways and viaducts, as close as only 2 cm (0.8 in). Care had to be taken to ensure that the stresses (vibration levels), resulting from the demolished pylons and decks hitting the ground, were below the no-damage thresholds for the nearby acceptors (structures receiving the vibra-tion stresses). These structures included bridges, houses and buried pipelines (water, oil and gas). In some cases, care also had to be taken to preserve the existing pylons supporting decks that were being demolished; since the same pylons were going to be used for the new viaducts (bridges). New continu-ous decks in weathering steel replaced the old reinforced concrete decks.

Jan 1, 2013

Process Study on Some Ag-Cu-Pb-Zn Polymetallic Ore in South China

Sep 13, 2010

By Forrest T. Moyer

Injury experience at coal mines and mechanical-cleaning plants (excluding officeworkers ) in 1967 was 222 fatal and 10,115 nonfatal disabling work injuries during an exposure time of 241.8 million man-hours. These injuries occurred at a frequency rate of 42-75 per million man-hours worked; the severity rate was 7,699 days lost or charged per million man-hours. Each of these general measures of injury experience was lower than similar data recorded for 1966. Employment at 6,885 coal mines and 569 mechanical-cleaning plants, excluding officeworkers, averaged 139,312 men in 1967. The average number of days worked was 220. Coal production totaled 560.8 million short tons, at rates of 2.32 tons per man-hour and 18.32 tons per man-day. A total of 2,779 onsite officeworkers at coal mines and mechanical- cleaning plants worked 5.2 million man-hours in 1967 without a disabling work injury.

Jan 1, 1972

Provide the U.S. mining industry with technology for designing environmentally sound, low-cost in situ leach mining operations to produce copper from small, deep, and/or low-grade copper oxide deposits. Approach Investigate the feasibility of a new mining method--in situ leach mining-as an alternative to conventional mining for copper. Study fundamental leaching technology that will facilitate future commercial operations. Develop guidelines and procedures that will enable mine operators to design and evaluate in situ leach mining operations for any specific copper oxide deposit.

Jan 1, 1989

IN this paper it is proposed to present certain features of operating practice at the Port Pirie works of The Broken Hill Associated Smelters Proprietary Limited, in the smelting in a blast furnace of lead ores carrying a high concentration of zinc.The subject matter selected for presentation is:(i) The effect of zinc on lead blast-furnace operations, together with an outline of the methods adopted in actual practice in dealing with the zinc problem.(2) Development of the height of tuyere above the bottom of the jacket, and the extension of the tapping interval and the combined effect of both factors upon the lead content of blast furnace slag.It will later be seen that one phase of the investigation carried out in connection with the effect of zinc on blast-furnace operations was largely responsible for the decision to increase to a marked degree the height of the tuyere above the bottom of the jacket.Due to this interdependence, it has been considered advisable to deal with the two features above mentioned.The high concentration of zinc in the lead-bearing materials smelted at Port Pirie has brought with it those troubles which are associated with zinc in the smelting operation.In the early stages of the history of The Broken Hill Associated Smelters Pty. Ltd. the trend towards increasing cost for labour, fuel, and stores, etc., rendered it necessary to increase the lead content of the charge, and reduce to a minimum the quantity of barren flux used.

Jan 1, 1931

By B. Anameric

The pig iron nugget process is gaining in importance as an alternative to the traditional blast furnace. Throughout the process, self-reducing?fluxing dried greenballs composed of iron ore concentrate, reducing-carburizing agent (coal), flux (limestone) and binder (bentonite) are heat-treated. During the heat treatment, dried greenballs are first transformed into direct reduced iron (DRI), then to transition direct reduced iron (TDRI) and finally to pig iron nuggets. The furnace temperature and/or residence time and the corresponding levels of carburization, reduction and metallization dictate these transformations. This study involved the determination of threshold furnace temperatures and residence times for completion of all of the transformation reactions and pig iron nugget production. The experiments involved the heat treatment of self-reducing?fluxing dried greenballs at various furnace temperatures and residence times. The products of these heat treatments were identified by utilizing optical microscopy, apparent density and microhardness measurements.

Jan 1, 2007

By S. Atallah

A survey was conducted relating to the current practices for the classification of hazardous locations in coal preparation plants. Several plants processing bituminous, anthracite and lignite coal in Pennsylvania, West Virginia, North Dakota, Colorado, Montana and Wyoming were visited. Coal preparation plant operations and designers as well as MESA inspectors were interviewed. The National Electrical Code was discussed with selected members of the NFPA committee and electrical equipment manufacturers. Data provided by MESA on fire and explosion accidents in coal preparation plants were examined. The requirements of the pertinent Federal Regulations, National Electrical Code, National Electrical Manufacturers Association and Underwriters' Laboratories were compared and evaluated. This report consists of two parts. Part I: "Analysis and Review" provides a summary of the findings. Part II: "Recommended Guidelines" consists of recommended uniform guidelines that may be used for interpreting the National Electrical Code as it applies to the classification of hazardous areas in coal preparation plants.

Jan 1, 1977

A reliable laboratory method to characterize the response of free gold particles to flash flotation conditions has been developed. The test has been performed on free milling gold ores as well as synthetic ores, using either a gravity concentrate or gold powder as the gold source, to assess the floatability of gold particles. Trends in free gold flotation kinetics, as well as size and milling effects, were identified for gold recovery based on the different feed types, reagent dosages, and residence times. It was shown that the ultimate recoveries and kinetic trends of gold particles from the gravity concentrate could be enhanced with increased dosage of collector, potassium amyl xanthate. Interestingly, in comparison to gravity-recoverable gold, recovery from pure Au powders was better in collectorless flotation, and cumulative recovery decreased with higher levels of collector addition. Improved coarse particle recovery appeared linked to increased collector additions for both the gravity concentrate and the pure gold powders. In general, coarse gold particles demonstrated slower kinetic rates thaen the fine or intermediate components incomparable tests.

Jan 1, 2015

By Terry O. Arney

This paper is a description of the digital Data Acquisition and control System that is installed at Cities Service's Pinto Valley Concentrator. Pinto Valley Concentrator ? The Pinto Valley Concentrator (5, 41 is located approximately seven miles west of the town of Miami, Arizona. The Concentrator is situated south of the open pit mine and was designed to process 40,000 tons of ore per day with an average grade of .45% copper. The comminution process consists of primary, secondary, and tertiary crushing, and single-stage closed-circuit grinding 161. Concentration of the copper sulfides is by means of froth flotation. Concentrates are transferred to the Inspiration Consolidated Copper Company smelter in Miami, Arizona through a slurry pipeline.

Jan 1, 1976