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An Integrated Solid Waste Management Method for Western Macedonia, Greece

Sep 13, 2010

By H. P. Willard, R. W. Gates

Basic Inc., has been mining magnesite and brucite for 27 years at Gabbs, Nev. This is a medium sized open-pit mine. The magnesite deposits are in north-western Nye County about 30 miles east of Luning, Nev., on the west slope of the Paradise Range, at an elevation between 5000 and 6000 ft. The magnesite and associated brucite is used to make magnesia refractories employed principally in the steel industry and magnesium oxide for various chemical uses.

Jan 10, 1963

By N. A. Gjostein

From their study of the anisotropy of grain boundary mobility in aluminum, the authors conclude that tilt boundaries have a higher mobility than twist boundaries because the atomic misfit at the pure-twist boundary is relatively small compared to the misfit at a tilt boundary for a given amount of misorientation. If this is true, then one would expect a twist boundary to have a lower grain boundary energy than the corresponding tilt boundary. Fig. 6, taken from the work of Gjostein and Rhines,10 shows that this is indeed the case for [001]-cu tilt and twist boundaries in the high-angle region, thus lending support to the authors' conclusion.

Jan 1, 1968

By Brian P. Stapleton, Bill M. Stewart, Joel R. Warneke, Curtis C. Clark

Of the 28 accident/injury classifications listed by the Mine Safety and Health Administration, handling materials is second only to roof falls in terms of generating the highest number of reportable accidents in active underground coal mines. Two materials-handling activities that cause numerous injuries each year are the categories of “handling supplies or material, load and unload” and “moving power cables.” Mechanization and mine worker activity training are two methods that can aid in preventing these injuries. This paper describes three mechanical methods—the mobile manipulator, the in-mine hoist, and a cable-handling system—being developed and tested at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Two of the devices are specifically designed for loading, unloading, and moving supplies and materials, and the third device is for handling trailing cables in the confined spaces of coal mines. Also described are safety solutions developed for underground coal mines geared to showing miners safe and unsafe ways of performing various materials-handling tasks.

By J. Pesl, R. Hurman Eric

Metal-slag phase compositions of molten iron and ilmenite smelting slags or solid titanate phases were determined between 1500° and 1700°C. The influence of oxygen partial pressure and impurity oxide additions including Al2O3, Cr2O3, MgO and SiO2 were investigated along with amount of reductant-carbon. The XRD revealed that the quenched slag crystallized as pseudobrookite (M3O5) solid solution in equilibrium with iron. Silica additions formed separate silicate phases because of its immiscibility in the titanate phase. Under strong reducing conditions iron oxide was almost completely reduced and the slag phase solidified as a consequence thereof. Cr2O3. SiO2 and MnO were also reduced to a high degree. Under weak reducing conditions the slag was fully molten and non of the impurity oxides were reduced. A significant portion of manganese, some magnesia and silicon, in the form of SiO gas, were removed via the gas phase due to their considerable vapour pressures. Alumina was not reduced under the applied conditions. A comparison of the experimental results with industrial data clearly suggested that industrial ilmenite smelting process operated under non-equilibrium conditions.

Jan 1, 2005

By Changsheng Song

With increasing depth of coal mining in China, the number of coal and gas outbursts has been increasing for years. By means of destressing the protective seam, the gas in the protected seam is drained to reduce gas concentration in the high gassy seams, thus ultimately attaining simultaneous extraction of coal and gas. Base on the simulated material scale modeling and numerical simulation, the protective seam mining method was practiced at No. 8 coal mine in Pingdingshan city. After extracting the No. 15 seam, the overlying strata movement and the deformation of No. 9-10 protected seam were studied. The experiments showed that it was feasible to destress the protected seams with large interburden thickness. As the protective seam was being mined, the protected seam experienced dynamic movement process and the change in vertical stress in the No. 9-10 seam assumed ?W? shape. When the face had advanced 656 ft (200m) from the setup room, the No. 9-10 seam was fully destressed, resulting in easy gas drainage in the destressed zone. Recommendations on mining sequence of multiple seams mining in the Pingdingshan coal areas were made.

Jan 1, 2008

Study on a Novel Polymer/Bentonite Compound Adsorbent for Removal of Cu(II) from Aqueous Solution

Sep 13, 2010

By James A. Finch

"I offer a personal view of what the next 30 years holds for mineral processing. Re-stating that mineral processing will remain a vibrant industry in raw material production, growth opportunities in waste management are identified. The processing sequence familiar now (mining -mineral processing -extraction) will become more interwoven. In situ processing (i.e., milling underground) will evolve from concept to demonstration. Opportunities to exploit physical properties altered in chemical (pyro-and hydro-) processing will present themselves. In primary grinding, the path to AG/SAG milling will progress with little deviation but opportunities in regrinding are wide open. Flotation will see the trend to designing bubble/particle reactors accelerate simultaneously with a vigorous response from mechanical cell suppliers. Gravity separation remains a bastion of the lone inventor but I anticipate that the new lines will come from the waste management business. I finish by examining the ""research cycle"", identifying growth in small ""high tech"" companies and university research centres.IntroductionI have been asked to offer a personal view of""where we are going in mineral processing?"". Gazing into crystal balls is quite a cottage industry as we approach the end of the millennium. Academics are often asked to assume the role of visionary, I presume because it is considered in their mandate, to reflect and philosophize (or, less charitably, because they are considered to have the time). Since this is the 30th Annual Canadian Mineral Processors Operators Conference, I am tempted to suggest the next 30 years as my frame of reference. This is about equivalent to one engineer's career or, given it takes typically 15 years to go from concept to realization in mineral process engineering (Napier-Munn, l 997a), about 2 ""invention cycles"". With this length of cycle, much that is familiar now will remain so over the 30 years.Research and development (R&D) is in response to need. The overarching need in mining is to find new ore bodies. Process developments cannot compensate for a depleting deposit or a declining commodity price. Mineral processing R&D is characterized by incremental gains, aimed at pushing the mine down the cost per tonne league table. Breakthroughs are the exception (flotation at the turn of the century was one). This must be kept in mind when trying to predict the future in our business."

Jan 1, 1998

By Alan D. Curtis

A standard planning block model for Phelps Dodge North America Operations has been developed to improve mine planning efficiency and performance in a skill starved environment. The model saves time on software management and training, consolidates data and standard information/output, enhances evaluation and strategic process, and improves communication between sites.

May 1, 2007

"NI 43-101 is a rule that governs how issuers disclose scientific and technical information about mineral projects to the public in Canada. The disclosure standards apply to oral statements as well as written documents and websites. NI 43-101 does not apply to disclosure concerning petroleum, natural gas, bituminous sands or shales, groundwater, or coal be methane. NI 43-101 first came into force on Feb. 1, 2001 and was revised in December 30, 2005. As a “National Instrument”, the law has been passed in each provincial and territorial legislature across Canada.“PART 1 DEFINITIONS AND INTERPRETATION 1.1 Definitions - In this Instrument “adjacent property” means a property(a) in which the issuer does not have an interest;(b) that has a boundary reasonablyproximate to the propertybeing reported on; and (c) that has geological characteristics similar to those of the property being reported on; “data verification” means the process of confirming that data has been generated withproper procedures, has been accurately transcribed from the original source and is suitable to be used; “development property” means a property that is being prepared for mineral production and for which economic viability has been demonstrated by a feasibility study; “disclosure” means any oralstatement orwritten disclosure made by oron behalf of an issuer and intended to be, orreasonablylikely to be, made available to the public in a jurisdiction of Canada, whether or not filed under securitieslegislation, but does not include written disclosure that is made available to the public only by reason of having been filed with a government or agencyof government pursuant to a requirement of lawother than securities legislation; “early stage exploration property” means a property that has(a) no current mineral resources or mineral reserves defined; and (b) no drilling or trenching proposed; in a technical report being filed in a local jurisdiction; “exploration information” means geological, geophysical, geochemical, sampling, drilling, trenching, analytical testing,assaying, mineralogical, metallurgical and other similar information concerning a particular property that is derived fromactivities undertaken to locate, investigate, define or delineate a mineral prospect or mineral deposit; “feasibility study” means a comprehensive studyof a mineral deposit in which all geological, engineering, legal,operating, economic, social, environmental and other relevant factors are considered in sufficient detail that it could reasonably serve as the basis for a final decision by a financial institution to finance the development of the deposit for mineral production; “historical estimate” means an estimate of mineral resources or mineral reserves prepared prior to February 1, 2001;“IMMM Reporting Code” means the classification system and definitions of mineral resources and mineral reservesapproved by The Institution of Materials, Minerals, and Mining in the United Kingdom, as amended; “JORC Code”means the Australasian Code for Reporting of Mineral Resources and Ore Reserves prepared by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute ofGeoscientists and Mineral Council of Australia, as amended; “mineral project” means any exploration, development or production activity, including a royalty interest or similarinterest in these activities, in respect of diamonds, natural solid inorganic material, or natural solid fossilized organic material including base and precious metals, coal, and industrial minerals;"

Jan 1, 2003

By Kjell Winther

"Hydralift Scanmec introduced early in the eighties a new and different mill design for very large grinding mills. The design described has actually no size limitation upwards and is so far suggested with motor power up to 40 MW. The mill is furnished with gearless ring motor drive transmission. It is totally fabricated, without heavy castings. The first installation, an 8, 1 MW ball mill dia. 6,5 m x 9,65 m length, has been in continous operation in 13 years without problems. Total grinding costs has been reduced with 3 0% compared to traditional smaller mills. Reductions has been achieved in maintenance cost, power consumption, liner wear and grinding media consumption.So far 3 ball mills of the described design are delivered and in operation, one grinding Iron ore and two grinding Nickel ore.IntroductionThe design of mills for mineral ore dressing has basically been unchanged since grinding in mills started some I 00 years ago, in spite of the fact that mills have grown larger and larger. This has resulted in structural and mechanical problems, causing expensive failures and loss of production.Hydralift Scanmec engineers were designing mills for more than 20 years according to the old «rules». As they experienced interest for an increase in the mill size at the time when reports about failing mills were published, they started analyzing the different mill parts to find new solutions. One goal was to only use elements from proven technology in the new design. Two key items were ring motor (wrap around motor)(Isch et al. 1977, Meintrup and Klein 1982, Ranze 1983) and large diameter pad bearings (wrap around bearings)(Fuller 1984), both acknowledged from other industries."

Jan 1, 1995

By D. Stüben, G. P. Glasby

"Abstract - Shallow submarine hydrothermal fluids from Paleohori Bay off the Greek Island of Milos have been investigated in detail. The extensive gas and warm (max. 93°C) water vents are enriched in major components such as C1-, Na+, Si, Ca2+, Mn, PO4 3-, NH4 +, K+, Sr2+, H2S and CH4 and depleted in Mg2+, O2 and SO4 2- relative to ambient seawater. Based on zero-Mg calculations, it is deduced that the submarine vent fluids are related to the geothermal reservoir beneath Milos which has a similar chemical composition. Fluid samples from each vent in Paleohori Bay represent a mixture of hydrothermal end-member fluids derived from the upper and deeper geothermal reservoir systems of Milos, a mantle-derived source, a high-chloride fluid resulting from phase separation of geo thermal fluids and a steam-heated CO2-rich meteoric water. Résumé - À l’île de Milos dans la mer d’Égée, des fluides sous-marins hydrothermaux en eau profonde ont été récherchés en détail près de la baie de Paleohori. Les larges émanations de gaz et d’eau chaude (temperature maximale: 93°C) sont enrichies en constituants principaux tels que de Cl-, Na+, Si, Ca2+, Mn, PO4 3-, NH4+, K+, Si, Sr2+, H2S et CH4 et appauvries en Mg2+, O2, SO4 2- comparé à l’eau de mer environnante. Selon le calcul du zéro-Mg, nous en déduisons que les fluides sous-marins hydrothermaux sont dérivés du réservoir géothermal sous l’île de Milos car leur composition chimique est la même. Les prélèvements des fluides de chaque source hydrothermale représentent un mélange de fluides hydrothermaux dérivés des réservoirs géothermaux supérieur et inférieur, d’une source dérivée du manteau, d’un fluide très enrichi en chlorure produit par la séparation des phases et de l’eau météorique enrichie en CO2 et chauffée par la vapeur."

Jan 1, 1999

By X Zhang, B McFadzean, P E. Ngoepe, B Nemutudi, P P. Mkhonto, S Pikinini

There is still a huge challenge in efficiently recovering the arsenides minerals that are largely concentrated in the Platreef Bushveld Complex which constitutes about 21 per cent of the platinum group minerals (PGMs). Therefore new collectors are required to improve the recovery separation of hard to float minerals, in particular sperrylite. The triazine modifications are promising reagents for mineral flotation and have not been given much attention in minerals processing. The adsorption of sodium 2,6-dithio-4-butylamino-1,3,5-triazine (SDTBAT), sodium 2,6- ditrithiocarbonate-4-butylamino-1,3,5-triazine (SDTTCBAT) and sodium normal butyl xanthate (SNBX) on sperrylite (100) surface were performed to identify a well performing collector molecule. We observed that the triazine collectors preferred to bridge on surface As and Pt atoms through the S atoms. We found that the adsorption energies were in the order: SDTTCBAT > SDTBAT > SNBX, indicating that the SDTTCBAT had strong exothermic adsorption on sperrylite and pyrite. These results showed that the ditrithiocarbamate had a great influence in the adsorption strength on the sperrylite surface. Importantly it was found that the triazine collector had stronger adsorption than the xanthate, which portrayed a promising replacement of xanthate collector. These results paved a way for design of novel collector for sperrylite and other chalcogenide minerals to improve their recovery.

Aug 24, 2022

By S. E. Olsen, M. Tangstad, G. Tranell, K. Berg, S. Gaal

In this study, the reduction behaviours of MnO and SiO2containing slags by solid carbonaceous materials was investigated in both small and larger-scale laboratory experiments. Five types of carbonaceous material were investigated: 2 graphites, industrial coke, anthracite and eucalyptus charcoal. The effects of the reductant type/properties on the reduction kinetics, metal composition and metal yield, have been quantified. Results show that the reduction rate is highly dependant on the type of carbon used. It was found that the reductant type significantly influenced the SiO2reduction while it did not seem to have a large effect on the MnO reduction. This may be due to the different CO2and SiO reactivities of the materials.

Jan 1, 2004

By R. S. Dean

The original flotation reagents were certain oils selected for a combination of properties that occurred fortuitously. It was recognized quite early in the study of flotation mechanism that, in order to function, an oil must have an active group-one that differs from the remainder of the molecule in its affinity for water or the mineral particle. Wark4 gives credit for recognition of this elementary chemical principle to the senior author of this report.5 However, it was soon found that simple hydrocarbons could not be used as flotation reagents and that two of the functions, which were combined in the early flotation oils such as pine and eucalyptus, could be obtained in separate compounds and their relative intensity controlled to advantage. These two functions were called collecting and frothing.

Jan 1, 1944

By Dale S. Preece, Stephen H. Chung

Electronic detonators and the attendant precise detonation timing that they facilitate are having a measurable effect on rock blasting in terms of improved fragmentation and vibration control. These improvements are increasingly well documented which is driving the expanding use of electronic detonators. In spite of the growing body of positive evidence concerning the benefits of precise delay timing, very little work has been done to document the impact of electronic detonators on the movement of rock. In this study 3-D computer programs, used to predict blasting induced rock heave, including the effects of detonation timing, are used to simulate the effect of precise timing on rock movement. Implementation includes quick, precise timing between blastholes going down a row and then much longer delays between rows of blastholes. For example an effective blast design might call for precise 3 ms delays between blastholes along a row and then 60 or 72 ms between rows. Several options are studied in this paper using computer simulations to draw some conclusions about the underlying physics affecting the process and how precise timing might have a positive impact on blasting induced rock motion.

Jan 1, 2005

By Poltak Sinaga

PT Kaltim Prima Coal?s 13-km (8-mile) overland conveyor (OLC) was commissioned in 1991. It is a conventional three-roller, 35 degree trough belt type. Cost and performance optimization during initial design resulted in a 5.4-m/sec (17.7-ft/sec) belt speed, 1,000 mm- (40 in.-) belt width to convey 1.35 kt/h (1,490 stph) and 7 Mt/a (7.7 million stpy) of coal. Despite a high initial figure, the belt speed was lifted to 6.5 m/sec (21 ft/sec) in 1996 to accommodate mine throughput in-crease. In 2002, a new low loss ST2100 1,100 mm- (43 in.-) wide belt replaced the ST2250 that was due to be changed-out. An upgrade project was initiated at the end of 2003 to further increase the belt speed to increase the OLC capacity to 30 Mt/a (33 million stpy). Upgrading the OLC by increasing the belt speed was the lowest capital option. Increasing belt width and/or modifying the trough angle to have larger cross sectional area was not an economical option because it would require expensive changes and significant down time of the OLC. To achieve 30 Mt/a (33 million stpy), the belt speed had to be increased to 8.5 m/sec (28 ft/sec). Although such high belt speed looked feasible, there was no information at that time of other OLC operating at such high speed. There was a risk that the conveyor would not operate safely and reliably at higher speeds. This risk was escalated by the fact there was no facility to lower or fine-tune the belt speed once the higher belt speed was implemented.

Jan 1, 2009

By M. Le Roux

Fine coal (-500 µm) is notoriously difficult to dewater. It is not uncommon for a dewatered product to have a moisture content as high as 30 per cent after vacuum filtration. This poses several handling and financial problems to such an extent that a lot of fine coal is discarded onto slurry waste ponds. A novel way of dewatering fine coal was developed at North-West University. It entails deliberately damaging the filter cake during dewatering to allow for an increased flow of air through the cake at the expense of the applied pressure differential. This method resulted in an average improvement in final cake moisture of between 3 per cent and 5 percent when executed in the laboratory under controlled conditions. A device was designed that could be fitted onto existing belt filters that would damage the filter cake as it passes by. This device was tested on a vacuum belt filter installation at a coal beneficiation operation in the Waterberg coal field in South Africa. The results showed a 3 per cent reduction in final moisture of the cake, proving the validity of the method at full industrial scale.

Jan 1, 2012

By Don A. Toth

Until recently, the fire protection systems used to protect mining equipment were based on generically designed, off the- shelf concepts. These systems were reliant on single agent approaches and were generally comprised of a series of small twenty or thirty pound chemical canisters that would discharge their contents when triggered by thermal detection means. As the equipment grew in capacity, the logic used to increase the protection was to add more chemical canisters to the system. Hydraulic excavators and large-scale mining trucks grew dramatically in size into the 1990?s and beyond; with this growth came the increase in major losses due to fire. This was evidenced throughout this period, and continues to be of great concern today. During this presentation you will learn of the significant changes that have come about as a result of this history. Today, dual-agent products, infrared detection and unit-specific, engineered systems are the primary phrases used when discussing how to best protect this equipment from fire loss. This session is a must for anybody looking to optimally protect their equipment assets and for those looking to renew and/or secure new insurance for high value equipment in the future.

Apr 1, 2005

By Howard I. Young

WHEN so many statements are being made relative to the requirements of zinc metal, it is difficult for some of us who are acquainted with the industry to visualize how it is possible to step up production so as to supply some of the fantastic requirement figures that are published from time to time. I shall attempt to approach this subject from the standpoint of existing conditions which affect production, also keeping in mind the price ceiling under which the industry operates. Total production of primary and secondary zinc in the United States for 1941 will be about 878,000 tons, to which should be added about 36,000 tons of Mexican slab zinc available for consumption or export from the United States, giving a total available of 914,000 tons. Production of slab zinc of all grades in 1942 should be 953,000 tons. Adding the available Mexican supply should bring the total to 989,000 tons.

Jan 1, 1942