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By Imre Gombköto, Barnabás Csoke

"Raw material management means not only mining and processing of primary raw materials like ores, but means also collecting and processing secondary sources of raw materials. Recycling is one of the most developing field of raw material management in Europe, and its solutions are derived from mineral processing roots and principals. Complexity and challenges of the field of recycling results innovative solutions of material processing- Since European Union identified 20 raw materials as critical (CRM) due to lack of primary sources within the border of the EU, recycling become more recognised as source of different raw materials. WEEE is the waste streams contains many of the critical elements and along them at least 15 different species of plastics of which recycling is delayed by a lack of effective separation technique. Most paper deals with separation methods based on different specific gravity, triboelectric charge or surface properties of plastic species. Plastics however have differences of thermal properties and thermoplastics, duroplasts and elastomers can be recognised. The experiments described in the paper aimed to determine thermo adhesive behaviour of plastic species often identified in WEEE streams for separation purposes. According to the results, some plastic types as PS, PP. PC or PVC and PET pairs are possible to easily separate from each other, however different additives are changing thermo adhesive properties of most of the plastics that makes industrial process difficult to develop. Along thermo adhesive behaviour, combination of physical interaction can be used to enhance separation selectivity.INTRODUCTIONPlastics has a relatively long term of history as a light, multi-functional material in construction, packaging, automotive industry and electric and electronic products. There are a numerous types of plastic species can be used for various applications therefore they amount are growing from year to year. This quantity however become part of the waste stream and while metal recycling has been done for decades due to its economic value - cheap plastic parts are less desirable as secondary products. In 2013 an annual 5% of plastic production growth has been estimated with a base data of 265 million tonnes at 2010 (Guiqing & Zhenming, 2013). Since landfill requirements are increasing while—especially in Europe where actual regulations are trying to deflect waste from landfills - landfill capacities are decreasing, costs are become more and more expensive, Applications like energy production based on plastics as a fuel or recycling are some of the options can be applied. Direct incineration of plastics are applied at many plants - in most cases where waste consist of dangerous substances are incinerated because plastics high calorific value helps correct average mixture composition enable operators reaching high enough temperature for combined power and heat generation while most of substances—like PAH, PCB or dioxins—are destroyed. Another path is using low temperature reductive cracking due to pyrolysis process, however the chance having higher concentrate of carcinogen substances in the products are higher since it applies around 400°C during the process."

Jan 1, 2016

By E. L. Schrader

Statistical Process Control (SPC) is a cooperative arrangement between a component or raw materials supplier and a manufacturing customer. The supplier must analyze his own manufacturing process and determine, predict, and control those variable elements in the circuit which affect finished product characteristics according to the customer's specifications. The results include: control of fluctuations in product characteristics to a narrow range, close communication between supplier and customer, and an increased responsibility for quality control placed on the supplier. In the mining and. processing of airfloated kaolin some unique problems arise with the SPC concept: 1) The SPC system was designed for manufacturing facilities that did not have to deal with natural variations in their raw material; 2) The airfloat process is relatively simple and offers limited opportunity to change processing steps or "fine tune" a circuit for special product needs; 3) Determining adequate sampling frequency for a plant which processes hundreds to thousands of tons per day is statistically difficult; and, 4) Due to the variety of customer industries served, different SPC programs must be set up to deal with widely varying specifications. For airfloated kaolin, SPC is "in line" process control, not after the fact "quality" control. The emphasis must be on statistically valid sampling of the kaolin ore and complete monitoring of its path through the beneficiation circuit.

Jan 1, 1987

By M G. Hawtin

The Rocklands copper project is a multilode, iron oxide copper gold (IOCG) + cobalt mineralised system located in the Eastern Fold Belt of the Mt Isa Inlier. Rocklands orebodies cover a range of oxidation zones from oxide, to supergene and primary. Each zone contains different economic minerals of interest. The supergene zones contain significant amounts of native copper and the primary zones are dominated by chalcopyrite. The juxtaposition of these oxidation zones and minerals make it an interesting mineralisation system.Current mine production sampling collects a nominal 3 kg drill chip sample from a 1 m composite, RC drilled interval. A site specific sampling procedure was needed to quantify introduced sampling error when taking grade control samples. Due to oxidation and mineralogical variation in ore zones we needed to develop a practically achievable sampling methodology that ensures minimum sample mass and sample error requirements are achieved to ensure ‘representative’ samples for all ore types.These issues are planned to be resolved using an experimentally derived method using principles from the Theory of Sampling. This method uses an experimental calibration of parameters K and a for Gy’s fundamental sampling error formula using a modified 32-piece sampling tree experiment to compile sampling nomograms for the primary and supergene ores. This paper demonstrates the process undertaken to improve the quality and standard of existing mine production sampling procedures at the Rocklands operation.Results indicate a sample mass of 5 kg for RC drill chips is appropriate for both the primary and supergene ores to achieve a fundamental error below 0.01 or 10 per cent relative error, which is slightly higher than the existing sampling protocol of 3 kg. An additional experiment is recommended to compile sampling nomograms using the exact laboratory comminution and mass reduction stage information to assess the use of a 3 kg sample. The results also indicate no changes are required to existing sampling protocols when sampling RC drill chips in primary and supergene ore at Rocklands.Sampling nomogram results also provide a useful ‘rule of thumb’ reference guide to other mining and exploration companies to help understand minimum sample mass requirements and sampling error during exploration drilling, resource evaluation and mining production stages when targeting similar IOCG mineralised systems. A sample mass of 5 kg is recommended when RC drilling similarly IOCG mineralised prospects and deposits in the Cloncurry area. Future test work is recommended when additional open cuts become active as well as including resource drilling drill core to provide better three-dimensional sample representivity.CITATION:Hawtin, M G, 2017. Minimum sample mass from reverse circulation grade control drilling at Rocklands copper project, in Proceedings Tenth International Mining Geology Conference 2017, pp 337–346 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Kenneth R. Hancock

The importance of "Mineral Pigments" can best be shown by noting that the world production is estimated to be in excess of 47 billion kilograms (52 million st). This quantity if pack- aged in the common 22.6 Kg (50 Lb.) bag and placed end to end would circle the world over 500 times. This world production figure is based on a broad concept that pigments, extenders, and fillers have essentially similar functions. In this paper mineral pigments are products produced synthetically or from selected minerals and through pulverization have characteristics of pigments.

Jan 1, 1985

By I. Y. Motovilov, S. A. Telkov, M. B. Barmenshinova, Z. S. Abisheva

As a rule, removing waste rock at the beginning of the process improves the conditions for the flotation of minerals, and also reduces the operating costs of crushing, grinding and flotation. Lead-zinc ores in the Shalkiya deposit of the Republic of Kazakhstan are classified as difficult for enrichment, but taking into account their significant reserves, they are one of the main potential ores for the production of lead and zinc. Under industrial conditions, for processing ores of the Shalkiya deposit, a selective flotation concentration scheme with the production of lead and zinc concentrates is recommended. However, according to the recommended scheme, it is not possible to obtain high-quality concentrates of lead and zinc, with high metal recovery. The paper presents the results of studies of preliminary gravitational enrichment of lead-zinc ore in the Shalkiya deposit. Based on the fractional analysis for the particle size range of -40+8 mm, Henri- Reingard enrichment curves were constructed, separation density (2730 kg /m3) was established to isolate the light fraction with the lowest possible lead and zinc content, and gravity enrichment indices (0.7-0.71) were determined. It was found out that when using gravitational enrichment of the original large-sized ore in the Shalkiya deposit, tails are released at the beginning of the technological process with a yield of up to 20% with the extraction of silica up to 30%, calcite up to 11% and carbonaceous matter up to 12%. As a result of the studies, it was found that the beneficiation of crushed lump ore could be conducted in heavy suspensions. One of the positive aspects of the use of gravitational enrichment is the reduction of energy costs for grinding the heavy fraction, which was experimentally proved in this article. Keywords: Lead-zinc ores, Shalkiya deposit, fractional analysis, gravitational enrichment, floating fraction, sunken fraction, separation density

Jan 1, 2020

By J. R. Arnold

The problem of recovering gold from a cyanide solution has been plaguing metallurgists since the cyanidation process was discovered in Glasgow, Scotland.1 The "perfect" method has never been found and this paper will not purport to fill that gap. But we, at Gold Fields, feel that we have developed a workable, cheap and efficient method of producing a refinery - ready product that has several distinct advantages over conventional electroplating techniques. The Gold Fields replating system is presently being used at their Ortiz and Mesquite operations. In short, the system electroplates the gold out on stainless steel wool, instead of mild steel wool as is usually done, then replates the gold by reversing the current onto stainless steel plates. By doing this the steel wool can be reused many times, the gold can be scraped off the plates cleanly and quickly, the operating costs are reduced and the slag production is greatly reduced.

Jan 1, 1986

By Lloyd Williams, H. K. Gibbs, William L. Crentz, J. W. Miller

"Reserves This investigation shows that the Poplar Creek is the most important bed in Scott County from a production standpoint. Although the Poplar Creek bed contains the largest reserve, the Big Mary has a larger recoverable reserve. Estimates of reserves also have been made for the Pewee, Red Ash, Windrock, Upper Pioneer, Jellico, and White Oak beds.Known measured and indicated reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 143 million tons as of January 1, 1954. Of this total, 74 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.Recoverable reserves of coal are estimated in beds 28 inches and more thick. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian region. The weighted average recovery for all beds in Scott County, as determined by this investigation, is 52.4 percent. This percentage is based on the total thickness of coal in the bed (less partings three-eighths inch or more thick) rather than on the thickness of the coal mined. Based on the weighted average percentage of recovery for all beds in Scott County, the recoverable reserves of coal are estimated to be 39 million tons as of January 1, 1954.Coal Analyses Chemical analyses of coal samples taken for this study show that the coal in Scott County is of high-volatile a bituminous rank except the Upper Pioneer bed, which is shown to be high-volatile B bituminous. The Pewee bed shows typical low-sulfur characteristics. The high ash and sulfur in the Big Mary are characteristic of that bed. The Poplar Creek is moderately low in ash and sulfur in areas where there is no parting in the bed."

Jun 1, 1956

By L. Martin, M. Raffaldi, M. Stepan, D. Benton

The Office of Mine Safety and Health Research, Spokane Mining Research Division, is continuing its high-energy, high-displacement testing of field-scale shotcrete panels. A test program was developed to determine the relationship between applied force, displacement and energy for both unreinforced and reinforced shotcrete panels. Reinforcement options consisted of synthetic macro-fibers, sprayed polyurea liners, chain-link mesh, welded-wire mesh and combinations of them. During testing, photogrammetry was used to measure the geometric changes of the panels, including volume changes and panel cracking. These measurements were correlated with the load and displacement data, allowing visual observation to be related to the applied force and displacement. The test results provide a comparison of the mechanical performance of the various panel types and can assist in interpreting the condition of installed surface support. Visual assessment of the loading cycle and strength capacity of shotcrete in underground excavations will improve mine safety by providing a means to better quantify the stability of installed shotcrete support.

Jan 1, 2016

F. E. BACHMAN, Buffalo, N. Y. (Communication to the Secretary) : The investigation so fully described by Mr. Laudig was undertaken with the idea of determining if it is possible to learn by expesiment, without an actual trial in the furnace, what economical results can be expected from the use of a given ore-mixture. The research was necessarily preliminary, and the results obtained are only to be depended upon so far as they relate to the samples treated. With the exception of the ores obtained from the stock-piles of the Buffalo Furnace Company, and several samples taken at a neighboring furnace, there is no certainty that the ores represented the average shipments of any mine. For this reason the publication of the names of the ores might do producers a great injustice. The names of the ores arc therefore withheld, and their identity is further .veiled by leaving out of the analyses the phosphorus-contents. The investigation was begun with the preconceived idea that the rate of reduction would be found to be dependent upon the accessibility of the particles of the ore to the action of the reducing-gas. In other words, a spongy, brown hematite or a very fine Mesabi would be the easiest reduced. I had formed a scale with No. 21 first, No. 30 second, No. 1 third, Nos. 5, 24, 25 and the remaining Mesabis fourth, etc , which is sufficient to show how much actual results differ from a judgment based on physical characteristics. The ore expected to be most easily reduced proved to be 25th in the list, while the one placed

Jan 1, 1897

Lignite is a kind of easy-to-slime and low rank coal. It is hard to be separated by the conventional wet coal beneficiation technologies. Meanwhile, in recent decades, a large amount of fine coal (-6 mm) is generated as the mechanized mining technology has been progressively deployed in coal sector, which causes a great difficult for lignite beneficiation and upgrading due to lack of efficient technology available. In this paper, a vibrated gas-fluidized bed was used to separate the -6 mm fine lignite particles. Separation experiments of -6+3 mm and -3+1 mm lignite were carried out in a laboratory-scale vibrated gas-fluidized bed. The effects of several parameters including the superficial air velocity, vibration intensity, bed height and exterior moisture content on the separation performance were experimentally studied. The results show that the optimal separation performance was achieved when the superficial air velocity is 0.3, the vibration intensity is 1.4, the bed height is 50 mm, the exterior moisture content is below 4% (-6+3 mm) and 2% (-3+1 mm). And the probably error E values of -6+3 mm and -3+1 mm size fraction of lignite are 0.202 and 0.225 respectively. The results indicate that a vibrated gas-fluidized bed can provide an effective solution for -6 mm lignite separation.

Feb 23, 2014

By David K. Hylbert

This study investigated stratigraphic and structural causes of roof falls in room-and-pillar drift coal mines in nine mines in eastern Kentucky. A contract modification provided for remote sensing studies in the Dunkard Basin of West Virginia and Pennsylvania. Results of stratigraphic and structural studies of an earlier contract (H0133018) were applied to several new mines. It was found that similar rock sequences contributed to unstable roof conditions. Structure contour and isopach maps were found useful In projecting these trends together with fence diagrams. Using Landsat imagery, a direct relationship was found between lineament direction and the trends of rock jointing, roof fall zones, "snap top" zones and sandstone channels in the examples cited. It was found that, by analyzing lineament intersections, from 50 percent to 65 percent coincided with roof falls.

Jan 1, 1980

By H. Kinilakodi

In 2008, the authors developed a methodology for identifying underground coal mines at high risk for major-hazard events. It focused on major hazard-related violations of safety standards associated with high-risk conditions. Later, using a sample of 103 mines with 2008 and 2009 data, injury measures and U.S. Mine Safety and Health Administration (MSHA) citation data were combined into a safe performance index (SPI). The SPI was used to assess the relative safety-related risk of mines, including by mine-size category. In this paper, comparisons are made of SPI-associated, normalized safety performance measures across mine-size categories, with emphasis on small-mine safety performance as compared to large and medium-sized mines. Mining Engineering, 2011, Vol. 63, No. 10, pp. 73-77. Official publication of the Society for Mining, Metallurgy and Exploration, Inc.

Jan 1, 2011

By Bertrand L. Johnson

Pure talc is a hydrous magnesium silicate (Mg3Si4010(OH)2). Pyrophyllite, although it resemble: talc in certain physical properties and uses, is a hydrous aluminum silicate (Al2Si4010(OH)2) - like kaolin, except that kaolin has a somewhat different composition (Al2Si205(OH)4) and structure. Soapstone can be considered essentially an impure talc grid when pulverized is used for many of the same purposes as talc. Massive, compact varieties of talc often are called steatite. PROPERTIES Talc and pyrophyllite are characterizes; by their softness (hardness on Mohs' scale, 1) their greasy feel, pearly luster, white color, and perfect basal cleavage. They have similar crystal structures, and this similarity explains the close resemblance of the two minerals in physical acid chemical properties. Talc is a good electrical insulator, resists the action of most acids and alkalies, and has an exceptional heat-retaining capacity. Its specific gravity is about 2.7.

Jan 1, 1939

By Thomas Bakley, Rob Lee, Jay Rodgers

The present state of technology in Controlled Blasting uses standard explosives’ products to create a crack between holes along a desired line of break. The resulting pre-split, post-shear or cut line is often of variable quality with unwanted damage at right angles to the desired cut line. A new concept in Detonating Cord manufacturing has provided a radically different performing explosive. This new Cord has reduced the Velocity of Detonation by more than a third. It changes the Detonation Pressure proMe of Detonating Cord to a lower and longer sustained pressure pulse. In addition, it develops more gas than conventional cords. At the same time it maintains all of the handling and reliability advantages of conventional Detonating Cord.

Jan 1, 2001

By L. Allan White

Instrumental analysis is an indispensable tool to many phases of research on rare-earth metals and their compounds; therefore, the development of new and improved instrumental techniques is essential. This report describes an emission spectrometric analytical method using direct-current carbon-arc excitation of various rare-earth-oxide mixtures. Lanthanum oxide serves the dual purpose of an internal standard and a constant major constituent. The versatility of the method was demonstrated by three different applications: (a) Analysis of complex rare-earth concentrates; (b) determination of impurities in high-purity rare-earth oxides; and (c) detection of rare-earth elements in other types of matrices, such as those resulting from beneficiation of rare-earth ores. The average error of analysis in the concentration range of 0.2 to 10.0 percent was 14.6 percent for a group of complex synthetic mixtures of rare-earth oxides. An average error of analysis in the concentration range of 0.05 to 0.50 percent was 21 percent for a group of high-purity rare-earth oxides.

Jan 1, 1959

By Roberto Maldonado Astorga

El presente texto señala la implementación del modelo de gestión para las operaciones de Volcán Campaña Minera, basado en el Modelo de Gestión de Malcom Baldrige. El modelo tiene el objetivo de establecer un proceso sistemático y estandarizado que asegure la mejora contínua y en línea con la visión de la empresa que apunta al logro de la excelencia operativa. La estrategia se divide en tres módulos: Módulo de Organización, Módulo de Gestión y Módulo de Comunicación. Asimismo se busca, implementar círculos de optimización permanente, monitorear de forma sistemática la ejecución de iniciativas de mejora y seguir el impacto en los indicadores.

Nov 1, 2014

By A Parry, C Fitzmaurice

After conducting laboratory ore sorting testwork on samples of a low grade nickel ore stockpile at Western Areas’ Flying Fox nickel mine, a mobile crushing, screening and ore sorting plant was located adjacent to the stockpile. An initial two month trial of the ore sorter program proved successful and was extended to process the entire Flying Fox low grade stockpile in a further four month campaign. A total of 167 660 t of low grade ore was processed, providing highly upgraded feed trucked 26 km to the Cosmic Boy concentrator. A more than three-fold grade increase was achieved on ore sorter accepts. The moderately upgraded fines that by-passed the mobile ore sorter were also subsequently blended into plant feed. This paper describes the mineralogy of the Flying Fox low grade ore, the mobile ore sorting campaign and provides some commentary on the economic and environmental benefits achieved in the ore sorting campaign. The ore sorting campaign demonstrated the benefits of being able to utilise mobile ore sorting equipment temporarily located adjacent to sub-economic low grade stockpiles in order to effectively treat these stockpiles and produce viable plant feed.CITATION:Parry, A and Fitzmaurice, C, 2018. The upgrading of low-grade nickel ore stockpiles at Western Areas Ltd Forrestania operations, using a mobile ore sorting plant, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 541–550 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Foster Fraas

The response of minerals in magnetic separators is in accordance to dynamic rather than static magnetic susceptibility values . The dynamic value varies with respect to both passage speed through the separating field and time of exposure in a preliminary treatment field . Tests on 16 minerals and solids have demonstrated that both of these factors affect different minerals in different ways .

Jan 1, 1964

By W. Kunda

Silver nitrate solution is a very common product in hydrometallurgical processes involving the treatment of various silver bearing materials. Silver is recovered by electrolysis. The alternative method for the recovery of silver from aqueous solutions is the precipitation by hydrogen at elevated temperature and pressure. A previous study by the authors revealed the feasibility of this technique for the silver ammine sulfate system. Further study showed different behavior for silver in the silver ammine nitrate system and a systematic study was initiated to establish the optimum conditions for the process. The study showed that the process can be controlled by (1) composition of the feed solution, (2) temperature and (3) hydrogen pressure. The recovered silver product was in the form of very fine powder.

Jan 1, 1989

By P Jonsén, S Larsson, M Parian, B I. Pålsson

The question of effective energy utilisation in grinding mills is not new. There are several conflicting arguments about tumbling mills, whether the efficiency is around 1 per cent or maybe 10 per cent, or even much lower. The energy not used is assumed to be lost as heating of the pulp, the grinding mill body, the charge, generation of shock waves and vibrations, etc. Stirred media mills on the other hand are generally considered to have better energy utilisation, but their energy efficiency is still not that clear. To shed some light on this a pilot-scale, wet stirred media mill was investigated over a range of operating conditions. The wet stirred media mill is a Drais PMH 5 TEX pearl mill fitted with an electric motor at 11 kW. It has been investigated over a range of operating conditions to try to balance the dissemination of the input energy in forms of the net grinding energy, mechanical energy losses, and the heating transferred to the pulp, the mill, the charge, and the cooling water. It is found that approximately 20–40 per cent of the input energy accounts for the grinding process. Also, that the difference between gross and net input electrical energy is mainly disseminated as heating of the pulp and cooling water. Mechanical energy losses appear to be much smaller than the heating effects. The use of a dispersant seems to mainly influence the heating effect.

Aug 24, 2022