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By M. Maldonado

A flotation bank is a serial arrangement of cells. How to optimally operate a bank remains a challenge. This article reviews three reported strategies: air profiling, mass-pull (froth velocity) profiling and Peak Air Recovery (PAR) profiling. These are all ways of manipulating the recovery profile down a bank, which may be the property being exploited. Mathematical analysis has shown that a flat cell-by-cell recovery profile maximizes the separation of two floatable minerals for a given target bank recovery when the relative floatability is constant down the bank. Available bank survey data are analyzed with respect to recovery profiling. Possible variations on recovery profile to minimize entrainment are discussed.

Sep 1, 2012

By Fu Ping-Hao, Sergio Mauricio Vianna, Ewen Silvester, Emmy V. Manlapig

"Over the last 5 years, an ambitious project has been undertaken at the Julius Kruttschnitt Mineral Research Centre (JKMRC) aiming to isolate, study and, if possible, model the effect of particle size, liberation and collector adsorption density on the floatability of mineral particles. As part of this project, we have conducted highly controlled flotation test-work, combined with state-of-the-art solution and surface analytical techniques such as High Performance Liquid Chromatography (HPLC), Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) and detailed mineralogical analysis to fully characterize the flotation behavior of a natural ore.The flotation tests were undertaken using a high-grade lead-zinc ore from BHP-Billiton’s Cannington mine (Australia) in a specially designed continuously operated laboratory scale flotation rig. Solution and adsorbed collector concentrations were measured independently during the course of the flotation tests using HPLC based ex-situ techniques. Liberation studies were performed using the JKMRC Mineral Liberation Analyser (MLA) on selected size intervals of different streams to estimate the specific surface area of galena. These results were used to calculate the collector adsorption density (collector coverage) on galena particles, with the eventual aim of developing a mathematical model describing the relationship between pulp chemistry, feed mineralogy, and floatability of galena particles."

Jan 1, 2003

By E. V. Manlapig

"Some researchers postulate that the floatability of a particle in the streams of an industrial flotation circuit is a function of only its size and liberation properties. They do not discount the importance of reagent or surface contamination on particle floatability but assume that the reagent coverage or surface contamination of the particle surfaces is essentially uniform for particles of similar size and mineralogical properties when subjected to a particular chemical regime.In this paper, samples collected from batch tests performed on different streams of the Red Dog lead cleaning circuit have been characterised with respect to their size, mineral association and mineral surface exposure. An analysis of this data set indicates that particle recovery rate is significantly affected by mineralogical properties - in particular the degree of valuable mineral surface exposure.However, through the use of a nodal analysis technique developed by the authors, it can be concluded that particles with the same size and mineral composition do not all float with the same rate, but with a distribution of rates. The characteristics of this floatability distribution do not change during the flotation process. It is suspected that the particles within a size mineralogical class in this study have varying degrees of surface oxidation and that this results in varying particle flotation rates. Thus basing particle floatability on size and mineralogical effects, alone, in a flotation model is not always valid."

Jan 1, 2003

By Peter N. Holtham, Geoffrey J. Lyman, Matthew S. Brennan, Vijay Subramanian, Rui X. Rong, Tim Napier-Munn

Studies of the dense medium and classifying cyclone have been conducted using the Fluent computational fluid dynamics code. Experimental measurements of the segregation of medium in a DM cyclone by gamma-ray tomography and the performance of a novel classifying cyclone design have been used to test and interpret the 3D CFD predictions. The predictions of the CFD models were generally plausible, though more work is required to incorporate turbulent mixing of the slurry in the cyclone. The benefits of the novel cyclone design were explained by the model in terms of conditions favouring reduction of short-circuiting at the vortex finder, and the removal of the air core from the wall at the apex. Work is continuing.

Jan 1, 2003

By Rod Hocking, Nenad Djordjevic, Randolph Pax

"Semi Autogenous (SAG) mills exhibit complex interactions between the competing processes occurring inside them. Traditional practice is to measure the operation of the SAG mill at an operating point in terms of its load, power draw, steel load, ore throughput rate, water addition rate and more recently the feed size distribution. However significant departures of operating conditions can occur due to changes, for example, in ore hardness, the quest for higher throughputs and mill internal geometry.Fundamental to SAG mill operation are the internal processes that ensure that a given ore throughput and discharge grind size are obtained and maintained. These processes can be measured using non-contact acoustic emissions from the SAG mills which utilise the information rich noise that is generated by the grinding, flow and charge movement inside a mill.Non-contact acoustic in-mill measurements can be used for the validation of discrete element modelling (DEM). The approach being reported in this paper is to model the individual physical processes and then to simulated the assemblage of a physical mill."

Jan 1, 2003

By Santiago Garcia, Dariusz Lelinski, Devan Govender, Tyson Baker, Mads Jespersen

"In recent years, the scale-up of mechanical flotation machines has been attempted with greater frequency. In contrast, the development of rotor-stator designs has been subject to greater inertia. The rotor-stator components are integral to the operation of mechanical flotation machines, responsible for the key physical processes of solids suspension, gas dispersion and energy dissipation. Design modifications are predicated upon the dual purpose of meeting customer needs while achieving metallurgical performance objectives. Accomplishing the latter is a rigorous undertaking, typically involving the sequential application of fluid dynamics principles, prototyping, smaller-scale research screening studies and larger-scale development projects. This industrial evaluation details the final stages of the forced-air rotor-stator development process using a double-refractory Carlin-type gold ore. A bypass stream of the primary rougher feed was further classified into cyclone underflow and overflow products. Four rotor-stator treatments were evaluated using parallel flotation rows coupled with a randomized statistical design. Only two treatments are compared in this initial assessment. Metallurgical responses were measured as a function of the random variation of key machine factors. Machine characterization measurements complemented the analysis of flotation performance indicators."

Jan 1, 2014

By W. H. Cheung

Nickel (Ni) plays a major role in the production of steel and other major alloys. There are two sources of Ni: laterite and sulphide ores. Global reserves of sulphide ores are being rapidly depleted, while there are enormous reserves of Ni laterite, much of it in Australia. As well as being present in huge amounts, Ni laterites have the advantage of containing cobalt (Co), a valuable mineral. Over the past decade, these factors have been driving the industry to explore the processing of Ni laterite. A route that has been used commercially in processing nickel laterite ore involves the thermal activation of the minerals by pre-reduction followed by ammoniacal leaching (Caron). Although this process has been effective in processing the goethite rich laterite minerals, the higher-grade serpentine-based minerals have been shown to be less susceptible to this process. This has been attributed to the formation of inert olivine phases. In this study, we examined the use of an alternative lixiviant, sulphuric acid, in leaching pre-reduced limonite and weathered saprolite nickel laterite ores. The specific aim of this study was to examine the sulphuric acid leaching of Ni and Co from pre-reduced laterite minerals, and to understand the role of mineral transformations in this metal dissolution. Synchrotron based X-ray diffraction was used to examine the transformation of goethite (FeOOH) to spinels and serpentine mineral ((Mg,Fe)3Si2O5(OH)4) to olivine. Reduction tests were carried out using CO and CO2 reducing gas mixtures and temperatures from 400 °C to 700 °C. The rate of formation and disappearance of specific Bragg peaks during reduction of specific minerals were used to derive an understanding of these solid-state reactions. Laboratory based reduction tests and leaching in sulphuric acid were used to validate the effect of these mineral transformations. The results suggest the versatility of sulphuric acid in leaching nickel from spinels and olivine, which was achieved at the expense of lower selectivity. Cobalt dissolution was found to be dependent on the nature of ferro-cobalt alloy formed during reduction.

Jan 1, 2014

By Pawel Strzalkowski, Marta Baszczynska, Urszula Kazmierczak

The paper presents issues related to interference of mining activities with the environment. Exploitation of mineral resources causes primarily a modification of the landscape. All of the negative impacts on environment are short-lived and last as much as it takes to exploit the raw material. After the mine closure reclamation is necessary during which all aspects that reduce harmful effects of the mining activities on the environment must be taken into account. Current ways of reclamation allow recreating natural environment, which is different from the original and enriched in diverse new values. This requires propositions of new forms of converted land development through a detailed analysis of technical, natural, planning, economic and social sphere requirements. Before making final decisions regarding selection of direction of reclamation, a thorough analysis of the key factors has to be carried out. All steps related to the implementation of the reclamation project are shown in the paper using Limestone Mine "Górazdze" located in the south-western part of Poland as an example. This paper also presents an analysis of current ways of post-mining reclamation towards agricultural and forestry landscape, along with our own suggestion for their extension in order to preserve biodiversity. For choosing optimal solutions the most relevant criteria were considered: existing natural values and possibility of their protection. Taking into account the economic and social aspects, supported by natural potentials, implementation of tourism and recreation in this area were proposed. It was shown that this proposition would not interfere with the current trends of the natural landscaping. Finally, after completion of reclamation and land development in the considered mine area, creation of a geo-park was proposed along with appearance of geotourism in the area. To illustrate the proposed forms of post-mining land development in the form of maps, an ArcGIS(ESRI) software was used.

Jan 1, 2014

By Vincent C. Smith, Agit Singh, Bernard Muller

The control of minerals processing plants is by no means trivial. In order to address some of the difficulties, it was decided to develop and test a model predictive controller (MPC) for a milling circuit. A milling simulator was written to test the MPC controller. Due to the large number of tuning parameters in a controller of this type, an optimising algorithm was written that automatically tunes the controller. Good, robust control was obtained when the controller was tuned using this algorithm. The controller was tested for various scenarios that are often encountered in the minerals processing industry. When problems were encountered, the MPC algorithm was specially adapted to accommodate for these difficulties. Control was further improved by using feedforward control as well as quadratic programming. The movement of the manipulated variables was reduced by using a region of uncertainty that allows the controlled variable to vary within a specified region around the setpoint. Integrators were handled by adapting the algorithm slightly and adding an optional integral error portion in the MPC controller. The performance of the enhanced MPC controller was compared to PI controllers on both the simulator and a commercial plant. The MPC controller showed faster responses with less interaction in both cases.

Jan 1, 2003

By J. Bouchard, Ali Vazirizadeh, R. del Villar

"The amount of water reporting to the concentrate correlates well with the solid entrainment. It is well known that the frother and collector dosage as well as the froth depth and gas rate influence the amount of water reporting to the concentrate. This is also true for gas dispersion properties such as gas holdup and bubble surface area flux. On the other hand, a positive bias rate, required to reduce hydraulic entrainment, also affects water recovery and thus the particle recovered by entrainment (depending on the their size). Up until now, the effect of the gas rate on the water recovery has been studied, but no comprehensive investigation on the gas holdup, bubble size and bubble surface area flux has yet been reported. This research precisely aims at addressing this issue. The experimental work was carried out under a constant gas flow rate to eliminate the gas volume effect, while other gas dispersion properties have been varied by modifying the frother concentration and the shearing water introduced to the frit-and-sleeve sparger. A constant froth depth and no wash water were used, in order to be able to evaluate the exclusive correlation between the water recovery and the bubble surface area flux and/or the bubble size. It is worth mentioning, that the particle size of the hydrophobic particles did not show a significant effect on the amount of water going to the concentrate. Not surprisingly, experimental results demonstrate that water recovery increases with the bubble surface area flux and with the gas hold-up."

Jan 1, 2014

By Anatoly Usov

The detailed researches of a broad circle of problems connected to development of the electric pulse method destruction materials (EPD) of a various nature and area of use are executed. The electrical and power characteristics of process, physical fundamentals of selectivity of a breakdown and destruction are investigated, the device of electric pulse (EP) disaggregation and ?omminution of materials are developed, the technological efficiency of disintegration of industrial minerals estimated. Due to its technological advantages, the EPD could have a great potential in minerals mining and processing technologies. Low specific power and weight-and-size characteristics of EP installations based on the existing out-of-date electric equipment are at present the main reasons hindering the effective application of the method in mining and processing technologies. The main studies carried out in Russia in the field of electro technical equipment development for EP technology are presented. The pulse capacitors service life affects greatly the economic efficiency of the process because the capacitors cost accounts for a considerable, and in some cases, the most part of the operational costs. Determined and analyzed in the study are the ways which could significantly improve the specific characteristics of high voltage pulse generators (VPG), such as to use of high-frequency voltage transformation to develop a charger; to use pulse transformers (PT) with iron magnetic circuits made of materials characterized by high magnetic permeability, in pulse generating circuits; as well as to use special ways which could produce voltage pulses with a short front. The experiments have proved the possibility to adapt these technological solutions for EP devices, and a further strategy of the EP technologies development and application has been suggested on this base. Keywords: electric pulse disaggregation, electric pulse installation, charger battery, high voltage pulse generator

Sep 1, 2012

By Mingxia Liu, Qi Liu, Tao Jiang

"In addition to physical parameters such as small mass and high specific surface area of fine and ultrafine minerals, chemical parameters such as the adsorption affinity of collectors on the minerals also plays an important role in fine particle flotation. In this study, we have examined collectors with two different ionized groups, carboxylate and hydroxamate, on the flotation of fine niobium oxide (pyrochlore). To facilitate comparison, two hydrocarbon radicals were tested: octyl and oleoyl, which led to four collectors that were studied: octyl hydroxamic acid (OHA), sodium octanoate (C8OONa), oleoyl hydroxamic acid (C18HA), and sodium oleate (NaOl). Small-scale flotation and isothermal microcalorimetric titration measurements were performed to determine the flotation recoveries of different sized pyrochlore and the enthalpic behavior after adsorption of the collectors on pyrochlore. It was found that the flotation performance of the carboxylate-based collectors was generally inferior to hydroxamate-based collectors. Sodium octanoate could not float pyrochlore irrespective of the particle size of the pyrochlore tested. With a longer hydrocarbon chain, sodium oleate was effective to float the relatively coarse pyrochlore (>20 µm) but its collection efficiency dropped sharply for particles smaller than 20 µm. On the other hand, the two hydroxamate-based collectors, octyl hydroxamic acid and oleoyl hydroxamic acid, showed good collecting ability to both the coarse and fine pyrochlore. The isothermal microcalorimetric titration studies indicated a consistent correlation of chain length with floatability of collectors for relatively coarse pyrochlore, as well as a positive relationship between the adsorption affinity and fine pyrochlore flotation recoveries. The key finding of this study was that efficient fine particle flotation could be achieved when strongly chemisorbing collectors were used.INTRODUCTION The first detailed study of the effect of particle size on flotation was made by Gaudin (1931) with sulphide ores. In 1942, Gaudin again demonstrated that (Gaudin et al., 1942) fine particles possess different flotation properties from larger particles. Since then the effect of particle size on froth flotation has been an important research topic by many researchers, e.g., Gaudin (1957), Miettinen et al. (2010), Warren (1976) Jameson (2010), summarizing the behavior of fine particles in terms of their low particle momentum, leading to low rate of collision with bubbles which reduces the chance of adhesion. The suggested remediation methods are mainly based on two approaches: increasing particle size or decreasing bubble size (Warren, 1976). Sand-fine splitting followed by separate flotation treatment of the sand and fines, using deep flotation cells, using starvation quantities of collectors, and using long flotation times, are also strategies to address the problems of fine particle flotation."

Jan 1, 2018

By Aysan Molaei, Kristian Waters

Solvent extraction is the one of the most common techniques for recovering metal ions from aqueous systems. However, solvent extraction is generally limited to relatively high concentrations and requires a high organic/aqueous ratio. Predispersed solvent extraction (PDSE) is a modified solvent extraction technique in which organic phase pre-comminute into colloidal liquid aphrons (CLAs). In this study, the extraction of copper by the PDSE technique was investigated. The main focus of this study was on the characterization and application of CLAs under different operational conditions, and to investigate the effects of different parameters on the extraction of copper from dilute streams. The effect of phase volume ratio (PVR), initial extractant concentration and initial copper concentration was studied and optimum conditions for copper removal using CLAs generated by LIX 984N as extractant, oil soluble and water soluble surfactants were proposed. Experimental observations indicated that PVR and initial LIX 984N concentrations had a significant effect on copper extraction.

Jan 1, 2014

By Lokesh K. Thakur, Peter Radziszewski

"For the cases tested (11 mills with 15 operating conditions), the Bond abrasion test steel media wear rate prediction gives an overall error of 73% and a standard deviation of 192.5%. However, total steel media wear in a given mill (ball or SAG) grinding process is a product of three recognised wear mechanisms -- impact, abrasion, and corrosion. A total media wear model can be defined on the assumption that the effect of each wear mechanism can be independently determined which allows for a total media wear model to be defined as the summation of the wear result of each mechanism (eqn. 1). It is assumed that impact and abrasive media wear is a function of the energy dissipated in impact and abrasion as estimated by a DEM charge motion simulation. Corrosive media wear is assumed to be a function of the media surface area present in a mill.The 3 initial tests developed (steel abrasion wheel, corrosion batch mill, impact chamber) coupled with the impact and abrasion energy spectra from a DEM charge motion simulation produced total steel wear rate results for the same cases as the Bond abrasion test giving an overall error of 0% and a standard deviation of 66.1%. However, if one were to consider the general observation that wear is proportional to energy and maintain the assumption that corrosion is proportional to media surface area then one would realize that the total media wear eqn. (1) can be reduced to eqn. (2). As this is a linear equation and one has, for the same mill, media wear and operating data for three different operating cases, one obtains three equations with three unknowns. This defines a simple matrix manipulation to determine the constants k1, k2 and k3. From the previous data set, we had 6 identical mills grinding the same ore but having different worn liner profiles and charge volume which provided the opportunity to average out the ki values over 20 combinations of 3 cases. With the determined ki values, it was possible to determine a second estimate of the contributions of impact, abrasion and corrosion to total media wear giving an overall error of 0% and a standard deviation of 56%."

Jan 1, 2003

By Carin Laubscher, Francis W. Petersen, Jaap P. Smit

Waste streams, such as acid mine drainage, are often characterised by low pH values and high concentrations of heavy metals, dissolved solids, calcium and sulphates. Although lime remediation effectively removes most of the heavy metals as hydroxides, it is less effective at lowering levels of sulphates. Various methods of removing sulphates from effluents exist, such as precipitation with lime, precipitation with barium salts, co-precipitation with calcium carbonate, reverse osmosis, and ion exchange. Mintek developed a chemical precipitation (SAVMIN) process to treat acid mine drainage, which entails the addition of lime to precipitate the metal hydroxides, and the subsequent formation (precipitation) of calcium sulphoaluminate or ettringite. The key to the viability of the new technology lies in the correct use, regeneration and recycling of Al(OH)3 used to precipitate the ettringite. The water produced by this process is suitable for disposal to watercourses or for agricultural, domestic or industrial consumption. No brines are produced as the salts are converted to solid hydroxides, gypsum and calcium carbonate. The technology has been tested on several different waters in pilot plant campaigns. Results obtained indicate that potable water can be produced (containing less than 200 mg/L sulphate and no heavy metals) as long as the monavalent ions (Na+, Cl-, etc.) are within limits.

Jan 1, 2003

By Megan Becker, Cyril O’Connor, Jenny Wiese, Gaynor Yorath

The effect of particle shape on true flotation has been widely reported. The present paper presents results obtained in investigating the effect of particle shape on the entrainment of particles during the flotation process. Different hydrophilic minerals with particles of varying aspect ratios were used and their shape determined using rheological tests and QEMSCAN. Their entrainment properties showed a close relationship to their shape with the recovery due to entrainment increasing as the aspect ratio of the particles increased. The effect of surface charge, by changing pH, and size of particles showed that the effect of shape was sustained at different pHs and particle sizes. Proposals are made to explain these observations in terms of the known relationships between drag coefficients and terminal velocities and shape. Since it has been previously reported that different milling procedures can affect particle shape, these results indicate that it is possible that such different procedures may result in increased entrainment of hydrophilic minerals.

Jan 1, 2014

By Sanggono Adisasmito

"The quality of the higher education in Indonesia is being improved by implementing a program financed by the World Bank under a project named QUE (Quality for Undergraduate Education). The investments are provided to selected study programs through a competitive selection process. The grant finances staff development, the purchase of equipments, textbooks, consumables, technical assistance, and incentives for outstanding faculties such as teaching grants, project grants, lecture note awards, and educational policy studies. These additional investments are provided to produce chemical engineering graduates that will compete beyond the national market.Chemical Engineering Department of Institut Teknologi Bandung in Indonesia has been selected to receive the QUE grant beginning the year 2000 and ending the year 2004. The department is actively involved in the mineral processing issues, particularly in the aspects of energy supply and the environmental protection. The activities are distributed in different laboratories and areas of expertise, such as: thermodynamics and utility systems, process equipment, chemical reaction and catalysis, microbiology and bioprocess engineering, process control, ceramics, as well as polymer and membrane technology. The main objectives of the QUE project are to improve the undergraduate program in the following aspects: Relevance, Academic atmosphere, Institutional management and commitment, Sustainability, as well as Efficiency and productivity, or abbreviated as RAISE. At the end of every fiscal year, the progress of the program is evaluated to measure the effectiveness of the project.The achievement of the QUE project objectives were assessed using performance indicators developed during the program design. There are six indicators to measure the performance of the individual program of study, such as: (1) Admission Test score, (2) average students' Grade Point Average (GPA), (3) average graduates' length of study, (4) graduates' waiting time before getting first job, (5) Test of English as Foreign Language (TOEFL) score, (6) Graduate Record Examination (GRE) score. Essentially, the RAISE evaluation criteria will be used to perform three main functions, such as (1) to measure the achievement through the six quantitative performance indicators, (2) to support the progress of evaluation and reporting throughout the implementation of the program, (3) to provide a universal framework for qualitative evaluation."

Jan 1, 2003

Spent automobile catalyst is an important secondary resource of PGMs (platinum group metals) and the recovery is significant. Various methods of recovery technology have been reported and applied in practical production, including pyro- and hydrometallurgical processes. Since the grade of PGMs in the catalysts is so low, approximately 0.5 wt. %, the present recycling technologies require high energy-consumption, it is of great significance to enrich the PGMs with some energy saving physical separation methods as a pretreatment. Automobile catalyst is usually composed of cordierite phase as a substrate and alumina phase, with PGMs, which covers the cordierite phase. We adopted the quenching pretreatment, one method of thermal shock, to generate micro-cracks between the two phases and separate the alumina phase from cordierite. Quenching was carried out by heating the catalysts in an electric furnace of different temperatures followed by rapid soaking into cold water. It was found that the phase boundary between alumina and cordierite was broken in the quenching and selective separation (detachment) of alumina from the cordierite could be achieved in the following surface grinding. The effect of quenching was checked by microscopic observation, hardness measurement, and chemical analysis. This paper figures out the stress formula of the quenching process, which is largely connected with layer thickness and temperature gradient by using an FEM (Finite Element Method) simulation and clarifies the mechanism of crack generation in the quenching process. Keywords: automobile catalyst, PGM, quenching process, FEM

Sep 1, 2012

By K. C. Corin

It is well known that the grinding circuit plays a crucial role in flotation. The effect of pulp chemistry during grinding is often overlooked. It is believed that the surface properties of the minerals can be adjusted during flotation rather than during grinding. However, recent development in surface analysis techniques (TOF-SIMS, XPS, and AES etc.) have proven that the hydrophilic iron hydroxides formed at the mineral surface during grinding make it difficult for collector adsorption, which may result in poor grades and recoveries of the valuable minerals. This study investigated the effect of the pulp chemistry conditions during milling and the subsequent effects on flotation performance of an Nkomati ore. The results have shown that there was approximately 10 % increase in Ni recovery, when the ore was ground at a dissolved oxygen (DO) concentration of 0 ppm (DO-0) in comparison to no gas control during the grinding stage. However, when the pH was changed from 9 to 11, no gas control resulted in a 20 % decrease in the Ni recovery compared to only 5 % decrease in the Ni recovery at DO-0. A noteworthy observation is that controlling a combination of DO and pH during grinding is of critical importance for better floatability and selectivity for such a system. It also became clear from this study that the presence of oxygen is critical to the consumption of xanthate, which is consistent with the general literature. It has been established that grinding at lower DO levels/redox potentials (Eh) in the presence of xanthate significantly improves the flotation performance of the valuable minerals.

Sep 1, 2012

By Fiona Sofra, Briony C. Ruse, David B. Boger

"The sustainability of the mining industry must be addressed through improving tailings management. The use of thickened tailings and pastes stems from a paradigm shift towards designing tailings disposal sites to suit their surrounding environment, rather than manipulating the environment to accommodate the tailings. Thickened tailings and pastes usually exhibit non-Newtonian behaviour, so a thorough understanding of the rheological characteristics of the material is required in order to determine the disposal plant operating conditions.Full Cost Accounting techniques may be used to provide financial justification for the implementation of alternative tailings disposal techniques through the calculation of a disposal cost per tonne of tailings over the life of the facility. Improved disposal methods such as thickened tailings disposal involve additional initial capital expenditure but reduce environmental impacts. The cost savings associated with environmental impact mitigation are reflected in Full Cost Accounting outcomes.Rheological characterisation is significant as a design basis that may be analysed using Full Cost Accounting to justify the initial capital expenditure of dry disposal systems for improved environmental performance."

Jan 1, 2003