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By D. E. Deegan, G. Holcroft, T. P. Johnson

"The rising cost of extracting metals from existing traditional deposits, increasingly stringent environmental regulations and a greater awareness of corporate social responsibility issues are all factors in stimulating the examination of mine tailings and small-scale alluvial deposits as a potential source of new raw materials. Furthermore, despite tougher economic times the demand for commodities remains strong, in no small part as a result of the growth of the world’s emerging economies.This combination of social and economic factors looks set to continue in the long term which will encourage greater recovery of materials from previously ignored sources such as mine tailings and ores from alluvial deposits.An expansion in the recovery of useful materials from mining-related activities is likely to require the use of robust and innovative techniques that have a built-in degree of future-proofing; DC plasma technology is one such technology.As a result of its ability to separate the valuable metal and minerals from the waste material while destroying hazardous compounds, Tetronics’ DC arc technology offers an alternative approach to resource recovery from a wide range of mine ores. Harmful cyanide compounds and the vast quantities of water used in conventional hydrometallurgical processing are avoided when plasma processing is adopted. DC arc technology also brings additional benefits, including: the extremely effective destruction of organic materials, the conversion of the inorganic material into a re-useable aggregate and the high tolerance of the process to fine and dusty materials. This paper presents details of Tetronics’ DC arc technology as one of the key pyro-metallurgical solutions available for the recovery of valuable materials from traditional mine ores and tailings, as well as giving specific examples of how the technology has been successfully employed in the recovery of enriched slags, ferroalloys and other metals."

Jan 1, 2016

By R. C. Becker

Welding is playing an important role in the manufacture of construction equipment as used in the mining industry. It provides design possibilities which are unique to this method of manufacture, and normally makes possible lighter weight but stronger products, which can be a definite advantage to a user. Welding is an industry that has experienced major developments over the past decade, all of which have improved our capability to make better welds and make them more economically. International Harvester Company has been introducing these newer welding methods into its manufacturing plants, particularly those producing construction equipment, just as fast as their value has been proven. This paper discusses how modern welding methods are contributing to the manufacture of strip mining equipment.

Jan 1, 1966

By Jesús L. Valenzuela, José R. Parga, Salvador Aguayo, Héctor Moreno

The Merrill Crowe zinc-precipitation process has been applied worldwide on a large number of operations for the recovery of gold and silver resulting in a higher consumption of zinc dust from cyanide solutions. However, in some of plants this precipitate is of low quality, because lead, cadmium and especially copper are precipitated along with gold and silver. The low quality precipitate also requires more fluxes in smelting and shortens crucible life. In this study, a process is introduced to remove copper, silver, lead and cadmium from barren solutions following the Merrill-Crowe process. Copper and silver are removed by precipitation in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. The recovery of lead and cadmium ions with natural hydroxyapatite using cow bone powder (CBP) as a new adsorbent material, is introduced. CBP is capable of removing lead and cadmium ions from aqueous cyanide solutions with 99% efficiency. It has the ability to compete with other existing commercial adsorbents for the removal of lead and cadmium. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 99 %; and for the cyanide associated with copper cyanide complexes, the recovery was 90%. Finally, the precipitate quality was improved 400% .This procedure was successfully run at three mines in México.

Jan 1, 2014

By F. Vagnon, A. M. Ferrero, M. Pirulli, A. Segalini

"The topic of this study is the design of flexible fences to mitigate the risk due to debris flow phenomena by means of theoretical and experimental studies analysed in framework of the Rock Engineering System (RES).The study of the interaction between debris flows and flexible barriers is a major challenge since many different aspects concerning both the slope characteristics and the structure features are involved. Debris flows are often triggered by the mobilization of debris deposits that are generated by rock fall of adjacent rock walls. The rock debris deposits are difficult to be characterized by the physical and mechanical point of view due to their large variability in volume distribution and, moreover, when dealing with high mountains environment, they are also strongly affected by the presence of water at different phases (solid or liquid) depending on the temperature. The debris deposit turns unstable in relation with the geotechnical and environmental features of the areas and the instability evolution in high mountain steep valley is often a debris flow. Debris flow destructive potential is very high and protections are often needed to reduce the debris flow risk.This complexity determines the needs of comprehensive study able to include the global basin dynamic and the environmental conditions. An a-priori analysis of the influence of the different aspects can be useful to focus on the real driving aspects of the problem. Due to the complexity of the system the application of the RES methodology is recommended in order to clearly define the different assumptions needed, their influence on the simulations and a comparison among them.RES allows investigating triggering criteria, flow and depositional processes and interaction of flows with protection fences in a rational way. For this purpose, an interaction matrix is created: it summarizes the key geotechnical parameters that influence debris flows, their interactions and debris/engineering protection opera behaviour. The goal is to quantify the diagonal-off terms to assess the residual risk after barrier construction, using back analysis from real debris flow event and data collection from literature.This methodology is applied to analyze a debris flow event in the Italian Western Alps where numerical analyses are carried on to assess flow characteristics to be used for fence design through the application of an analytical and numerical model developed by the authors (Brighenti et al, 2013). In particular, the velocity and deposition heights have been estimated using the numerical code RASH3D (Pirulli, 2010), which is a single-phase model based on depth-averaged Saint Venant equations. Pathways of different lengths are studied to assess the input data necessary to design the protection barrier and to determine the associated risk. Simulation of the barrier at different places along the valley will also allow to determine optimal barrier location in terms of minimum residual risks by comparing the velocity, the volume and the energy of the debris after the barrier impact.The work will produce a possible design scheme to be adopted in this environment."

Jan 1, 2015

By B. Grinbaum, A. Mazuelos, F. Carranza, N. Iglesias, M. Avila, J. L. Lozano, G. Perez, R. Romero, M. \/aliente

Following a failure of a tailings pond darn at a mine in Andalusia, Spain, a huge effluent stream, that contained about 1 g/1 Zn and significant amounts of ferrous, ferric, calcium, copper, aluminium and manganese cations has to be treated, to prevent pollution of a nature reserve. EGMASA, as the regional government environmental agency, suggested to improve the current depuration process by recovery of the Zn from the effluent. A solvent extraction (SX) followed by electrowinning (EW) was proposed and developed to remove zinc.. A pre-treatment stage consisting in bio-oxidation of ferrous iron by using a bacterial process followed by an alkaline precipitation was employed because iron in the effluent is incompatible with both the SX and the EW processes. The SX process was developed successfully at the laboratory scale and verified in a pilot plant on-site, using two Bateman Pulsed Columns for extraction and stripping of zinc. The results were satisfactory obtaining a recovery of 90% of Zn. The process was suitable for industrial application.

Jan 1, 2008

By S. Hunt, S. Jayasekera, J. Kyle, N. Perera, K. Stone

A preliminary investigation has been conducted to determine the conditions for the precipitation of phosphate from the liquor produced after a hydrochloric acid pre-leach and rare-earth recovery from a rare earth containing fluorapatite concentrate from the Nolans rare earth deposit in the Northern Territory of Australia. The results show that at 50oC the phosphate can be precipitated in two stages using limestone to produce a Stage 1 precipitate containing most of the impurities including iron (94%), aluminium (92%), fluoride (98%), uranium (84%) and thorium (94%), followed by a relatively pure Stage 2 dicalcium phosphate precipitate (DCP) containing only 0.05% Fe, 0.05% Al, 0.1% F, 0.01% U, and <0.01% Th. The initial Stage 1 precipitate contained about 25% of the phosphate while the remaining 75% reported to the Stage 2 phosphate precipitate. Depending on the required radioactivity specifications, the amount of phosphate in the Stage 1 precipitate could be reduced. Reagent requirements were 11.4 kg limestone (as pure CaCO3) per cubic metre of solution for the Stage 1 precipitate and 39.7 kg limestone (as pure CaCO3) per cubic metre for Stage 2. The analysis of radionuclide balance indicated that radionuclides deported mainly to the final filtrate (86.4%) compared to Stage 1 precipitate (5.4%) and Stage 2 precipitate (8.2%). Settling and pressure filtration tests indicated the precipitates were both readily settled and filtered. The final moisture contents of the Stage 1 and Stage 2 precipitates were 62.5% and 49.3%, respectively.

Jan 1, 2014

By W. Dziurzynski, St. Wasilewski, T. Palka, A. Krach

"Air parameter monitoring systems, regardless of gasometrical protections, provide a significant number of measurement data. The obtained data broadens the knowledge on processes taking place in underground workings and shows the relationships and influence of machines and technological processes on the variability of ventilation parameters in the areas of longwalls. Nowadays, computer simulation methods are increasingly used to reproduce the flow of air and methane mixture in the area of longwalls equipped with shearers. The paper presents the results of a research experiment covering a long-term observation of a longwall area during mining with a shearer using sensors from the mine's monitoring system. Data from sensors for methane concentration, pressure and velocity were used and additional ventilation measurements were taken to determine the parameters characterising the air flow in the area. The influence of different machine cycles in the longwall on the changes of air parameters in the area of the longwall was shown. A numerical model of the ventilation area was developed and the computer program VentZroby was used for the calculations, which allows for the simulation of the process of ventilating the area of the active longwall during the extraction of coal with the use of a shearer and haulage of the run-of-mine. Computer simulation of the influence of the shearer's operation and the methane inflow associated with the distribution of the mixture of air and methane was carried out. The results of the simulation were compared with the data recorded by the monitoring system’s sensors during the measurement experiment. Comparison of the recorded methane concentration courses with the results of a computer simulation of the air and methane flow conditions in the mining area showed changes in the gassiness. INTRODUCTION Studies carried out in the Polish and global mining industry show that methane is an obvious factor in limiting mining production due to the loss of continuity in the operation of longwall complexes in hard coal mines under methane emission hazard (Schatzel et al., 2008). In addition, methane hazards have a significant impact on the safety of the operators of machinery in the longwall. The requirements of Polish regulations and the practice of safe operation of mining longwalls require correct determination of gas concentration, volume flow, as well as pressure and temperature of the flowing air. As part of the research undertaken in the Budryk (Wasilewski, 2010) and Bielszowice (Dziurzynski et al., 2009) mines to assess the methane hazard in the longwalls and workings in the vicinity of the longwall, research experiments were carried out, during which air parameters were recorded by the mine monitoring system and additional testing equipment in different cycles of shearer operation."

Jan 1, 2019

By Eric Poulin, Anthony Clapperton, Jocelyn Bouchard, Jaime Cristobal Rojas-Montes, Benjamin Legare

"Several grinding mill dynamic simulators have been developed in the last half-century. However, complete circuit simulations are mainly limited to academic investigations, and on-site applications for advanced control or real-time optimization are scarce. One particular issue that has certainly curbed a more widespread use is the time and efforts required for model calibration. This paper illustrates this challenge and presents a calibration method based on dynamic simulation using industrial data and laboratory testwork. The simulator models discussed originate from the work of Austin and Luckie (1972) for grinding mills, and Plitt (1976) for hydrocyclones. A two-stage approach based on a least squares minimization allows determining calibration parameters values. Firstly, laboratory testwork are required for characterizing breakage coefficients of the ore. Secondly, step change responses and their simulation— effect of ore and water feed rates on output flow rates and size distributions—allows identifying transport/mixing conditions. Simulation results are in agreement with actual process responses to variations of feed conditions obtained from a plant survey.INTRODUCTIONDynamic models for grinding circuits has been intensively studied since the 1970's notably by Austin and Luckie (1972b), Klimpel and Austin (1984), Rogovin and Hogg (1988), Napier-Munn et al. (1996), Liu and Spencer (2004), and King (2012) among others. The resulting models primarily serve in simulation applications for process equipment sizing, which incidentally also helps developing a better understanding of comminution operations. An obstacle curbing a more widespread and targeted use of grinding simulation for process control and optimization purposes is the time and efforts required for dynamic model calibration. It remains a cumbersome task that is typically not well detailed in technical papers. This could explain why dynamic process simulators are mainly confined to academic applications."

Jan 1, 2016

By Gordon A. Irons, H. Y. Hwang

An impinging gas jet on a water surface was studied to understand momentum transfer in oxygen steelmaking. Depth, width and oscillation frequency of the jet cavity were measured and the splashes interpreted with Kelvin-Helmholtz instability and combined Rayleigh-Taylor and Kelvin-Helmholtz instability theory. A model to calculate separate gas and liquid velocities, applying the exact momentum boundary condition, is proposed.

Jan 1, 2004

By L. G. Bergh

The experience developing a supervisory control and information systems in a SX pilot plant is presented. The plant is located at the Process Control Laboratory, Santa Maria University, in Chile. In this work, the problem of controlling this process is discussed and related literature is briefly reviewed. Then, an innovative control scheme organized in three levels, local, hydrodynamic, and metallurgical supervisory controls is presented in an architecture including field controllers, PLC, and PC networks. Operating decisions in the metallurgical supervisory control are taken with incomplete information from on-stream analyzers. The control proposed is based on metal and acid concentration predictions of intermediate and exiting streams through the use of dynamic and static models and flow rates and input concentration measurements. Preliminary results are presented. The main objectives are to develop and test intelligent techniques in a hybrid system, and to study measurement and supervisory control problems. It is expected to produce reliable results that will contribute to improve the efficiency of this emerging and important process.

Jan 1, 2007

By R. Grau

"After commissioning and start-up of the first 500m3 TankCell® flotation cell in 2014, the over 300m3 mechanical flotation cells have earned their place in large-scale flotation operations. These 500 to 630m3 cells, designed for projects with large throughputs, are proven to provide savings in project capital and operational expenditure through savings in foot print, energy consumption, and less equipment to install and maintain. Addition to savings in different phases of a project, these cells provides operational flexibility and has shown improvements in metallurgical performance. In this paper a case study from Kevitsa TankCell® e500 installation and Buenavista del Cobre TankCell® e630 installations will be given.INTRODUCTION After development (Grönstrand and Bourke, 2008), characterization (Morales et al. 2009; Yanez et al. 2009; Grönstrand at al. 2009), validation (Elgueta et al. 2009; Coleman and Dixon, 2010), and more than 350 industrial installations of the Outotec TankCell® e300 flotation cell, the well proven energy efficient TankCell® product family introduced the TankCell® e500 forced-air flotation cell late June 2012 (Outotec.com, 2012). The introduction of the 500 m3 flotation cell followed by introduction of a 630 m3 flotation cell, TankCell® e630, in October 2014 (Outotec.com, 2014). These large flotation cells are designed for projects with high throughputs where the number of cells needed for operation with smaller equipment would become large. The benefits of this size of flotation cells comes from the lower capital expenditures due to lower equipment costs, savings in plant footprint, less installation work with less auxiliary equipment, lower energy consumption, and less units per installation resulting in less components, spare parts and maintenance.The first TankCell® e500 was commissioned and taken into operation in October 2014 at FQML Kevitsa Cu-Ni-PGE concentrator, nowadays owned by New Boliden. The first TankCell e630 was taken into operation in January 2018 at GrupoMexico’s Buenavista del Cobre Cu-Mo concentrator. The start-ups of the first TankCell® e500 and TankCell® e630 followed with test work where the hydrodynamic performances of the cells were characterized and metallurgical performance studied. The results of the TankCell® e500 test work were presented in detail by Mattsson et al (2015a; 2015b) and TankCell® e630 by Grau et al. 2018. In this paper the metallurgical improvements achieved with the large cell installations will be presented."

Jan 1, 2019

By F. W. Gray

Foreword: It is not my purpose, in this address, to write the history of the Geological Survey of Canada, which has from time to time been reviewed by the officers of the Survey itself, and by men more competent than myself to handle so large a subject, but rather to set out some of the reasons for the regard in which the Survey is held by our Institute, the body best qualified to speak for the mining men of Canada. And, a further purpose is to publish the desire of our Institute that the work of the Survey shall be maintained at the highest pitch of efficiency the resources of our country. will permit, because to scrimp expenses on the Survey is &apos;to save at the spigot and lose at the bunghole." A historical examination of the grounds on which it may be asserted the Geological Survey has been, and still is, of fundamental economic value to our country, discloses a prescience on the part of the forefathers of Canada, calling for our admiring gratitude, and reveals a unanimity among the real leaders of Canadian thought, on the value of geological knowledge, that is impressive in its continuance dawn to this date. There seems always to have been before our people the realisation that large stretches of Canada are unfitted for agricultural settlement, and that our glaciated areas, the barrens and tundra of the North, and our extensive mountain ranges, had promise of compensating mineral content which the geologist and the prospector, labouring together through the years, would disclose. The Geological Survey is one of Canada&apos;s oldest public services, distinguished by an unimpaired tradition of honourable and useful labour. Founded in 1843, under William Edmond Logan, not yet &apos;Sir William&apos;, one year after the Act of Union, it was directed by him until 1869, or into the early years of Confederation, so that the early years .of the Survey were also, politically, the formative years of Canada, as we know her today.

Jan 1, 1932

By W. Leblanc, J. Phalen

This paper tells the story of a serious mine fire on a mechanized longwall face in a submarine coal mine at Glace Bay, Nova Scotia. The story gives, in chronological order, a technical account of the steps taken to investigate, fight and contain the fire. The time during which the events took place spans from June 19 to November 7, 1975.

Jan 1, 1976

By A. Rao, J. A. Davidson, B. L. Jones, K. W. Bowes, D. Craib

Supported by ANSTO, Groundwater Science and Inception Consulting Engineers, Boss has embarked on a series of technical projects aimed at reinforcing the Project’s capability to meet its export permit production capability. This paper will focus on three aspects of this technical program: Reducing the cost of resource expansion through smart use of low cost, surface target generation techniques; Improving the rate of uranium leaching and solution stability (gypsum, jarosite) through lixiviant chemistry modifications; and Development of an ion exchange (IX) process to increase production capacity, and integration of IX and the current solvent extraction circuit with the existing uranium precipitation and product preparation circuits.

Jan 1, 2020

By L. Gutierrez, M. Pawlik

The rheology artificial mixtures of bitumen with fine quartz of varying bitumen content, as well as actual oil sand ores, was investigated under different physicochemical conditions (pH, temperature). All rheological measurements were conducted using a Haake Rotovisco VT550 rotational viscometer, connected to a fixture specifically designed to measure properties of settling suspensions. It was found that at low bitumen contents (1 %, wt.) the pH of the slurries was the most important parameter that controlled the rheology of quartz-bitumen slurries. At higher bitumen contents (10%, wt.), it was a combination of high temperature and high pH that gave the lowest apparent viscosities and yield stresses of the model mixtures. These model observations correlated well with the rheology data obtained for slurries of actual oil sand ores. The overall results were discussed in terms of aggregation-dispersion phenomena between bitumen and mineral particles.

Jan 1, 2009

The use of QemSCAN in providing mineralogical input to detailed ore and product characterization has proved of immense value in recent years. In this paper, a brief review of selected Cu-case studies is presented to demonstrate the versatility of automated, quantitative mineralogy by QemSCAN. This versatility ranges from measurement and analysis strategies through to data processing and presentation. As a rapid diagnostic service, it is common to find that only grain size, the degrees of liberation and/or ore mineral modal mineralogy are of interest. By contrast, the detail afforded by the simultaneous determination of both gangue and ore minerals can alert mineral engineers to fatal flaws and attributes deleterious to processing that are directly a function of silicate and other gangue mineralogy. Examples of the latter effects include the influence of micaceous minerals and acid consuming species, while the former include fluorine minerals, which can provide both processing and environmental challenges.

Jan 1, 2007

By A. S. Nortjé

At South Deep Gold Mine longhole stopes are backfilled using a cemented Cyclone Classified Tailings in its hydraulic state. The need to contain the hydraulic fill until cured requires a barricade. Due to the massive size of the stopes, the tailings can exert enormous forces on any such barricade. Barricades have long been in use, but recent failures in Australia and the large rate of filling required at South Deep solicited a robust design. A robust design must examine all foreseeable failures and the barricade must be able to resist all expected and, within limits, unexpected loads. The design should also be simple to construct and cost effective, limiting the impact of construction errors and unnecessary delays to production.

May 1, 2007

A study was made to determine the effect of increasing concentrations of dissolved oxygen on the floatability of galena pyrite and chalcopyrite. Adsorption, flotation and contact-angle tests were done in deoxygenated, in air-saturated and in oxygen-saturated solutions. The results showed that the adsorption of collector increased as the concentration of oxygen increased. Adsorption followed the exponential law r = kC'/"• Discontinuities in the curves were observed after the adsorption of several monolayers of collector. Although adsorption increased with increasing oxygen concentration, the floatability of the pyrite minerals did not increase, because oxidation had adverse effects on the floatability of these minerals. The floatability of galena was maximum in oxygen-saturated solutions, pyrite was depressed and chalcopyrite was also slightly depressed. Contact-angle tests proved that a bubble could not be attached to large flat surfaces in deoxygenated solutions, because sufficient surface free energy was not available for adhesion after the deformation of the bubble. In the presene of air, all the minerals yielded the same maximum angle of 72 degrees, characteristic of isopropyl xanthate.

Jan 1, 1970

By A. Karzhau, B. Aldamzharov, Y. Tussupbekov

"This case study produced for the metal mine operating in Kazakhstan, which has ventilation controlled manually and working continuously at maximum speed to keep air flowing through each part of the mine 24 hours a day. The mine auxiliary ventilation has been designed with the maximum length of ducting systems with extra air volumes to compensate for potential leakage. The mine provided auxiliary ventilation to all production stopes even to those, which for various operating reasons become temporarily inactive. However, mine safety has to consider risks associated with the deficit of fresh air for mine gases dilution and removal. The mine needs additional investments for re-designing ventilation network and therefore needs to estimate financial risks associated with it. The aim of this study is to conduct risk analysis for ventilation network optimisation processes at the operational metal mine in Kazakhstan. Mine ventilation surveys were undertaken for validation of the computerised ventilation model. The mine ventilation network modelling has been undertaken to be compliant with Kazakhstan mining regulations. Results of the mine ventilation optimisation processes were analysed in terms of financial risks for investments into reconstruction of the ventilation shafts, extension of the ventilation network, variable speed fans and automated regulators. Savings were resulted from improving ventilation system efficiency by reduce airflow in areas without mining activity and redistributing existing ventilation capacity. Based on savings derived from the optimised ventilation network an additional NPV has been received. Stochastic modelling use Monte Carlo simulation producing representation of possible outcomes for the additional NPV considering electricity pricing as a major variability. As result probability distribution for the optimised ventilation network demonstrates the additional NPV in a range of 1.6 - 2.2 million US$ in the corresponding defined value of 90%. Moreover, there is only 5% chance that the additional NPV to be less than 1.5 million US$. Conducted risk analysis for ventilation network optimisation processes gives considerations on volume of investments into the mine ventilation system.INTRODUCTIONCosts for mine ventilation are typically increasing when mines expand to deep levels. Some underground mines in Kazakhstan still use continuously operating fans at its maximum capacity. This is not helping to save energy and costs that are in many cases very significant. This case study produced for the metal mine operating in Kazakhstan, which has ventilation controlled manually and working continuously at maximum speed to keep air flowing through each part of a mine 24 hours a day. The mine auxiliary ventilation has been designed with maximum length of ducting systems and extra air volumes to compensate for potential leakage. The mine provided auxiliary ventilation to all production stopes even to those, which for various operating reasons become temporarily inactive. However, mine safety has to consider risks associated with the deficit of fresh air for mine gases dilution and removal from the mine workings (Sabanov, 2019). The mine needs additional investments for re-designing ventilation networks and therefore need to estimate financial risks associated with it. The aim of this study is to conduct risk analysis for ventilation networks optimisation processes at the operational mine in Kazakhstan. Mine ventilation surveys for validation of the computerised ventilation model have been undertaken"

Jan 1, 2019

By Minerals Refining Company, Gerald Luttrell, Biao Li, Robert Bratton, Roe-Hoan Yoon, Stan Suboleski, Nikhil Gupta

Flotation is regarded as the best available method of upgrading coal and mineral fines in the mining industry. However, its efficiency deteriorates rapidly with decreasing particle size. Furthermore, ultrafine concentrates are difficult to be dewatered economically. Due to these technological problems, some operators are forced to discard at least part of the ultrafine materials to tailings (or refuse) ponds, causing significant losses of valuable resources and creating environmental concerns. To address these technological issues, a new separation process named hydrophobic-hydrophilic separation has been developed on the basis of the recent advances in the science of hydrophobic interactions. The results obtained to date show that the process can recover and dewater ultrafine particles simultaneously with high separation efficiencies. Following a series of extensive laboratory tests, the process has been scaled up to proof-of-concept and pilot-scale continuous tests. The results obtained with desliming cyclone overflows, screenbowl effluents, and by-zero coal flotation feeds can be cleaned to less than 4% ash and moisture with over 97% organic matter (or coal) recoveries. The results obtained with mineral fines also showed encouraging results.

Jan 1, 2016