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By Jie-Liang Wang, Yongdan Cao, Zhao Cao

"The effect of ethylenediamine tetraacetic acid (EDTA) on flotation separation of fluorite from bastnaesite and its selectively depression mechanism on fluorite were studied by single mineral flotation, artificial mixed minerals flotation, solution chemistry analyses, Zeta potential and XPS measurements.The results show that fluorite can be deeply depressed by EDTA while the flotation of bastnaesite is almost unaffected when octanohydroxamic acid (OHA) is used as a collector. The separation index (SI) between bastnaesite and fluorite increases with the dosage of EDTA, SI can be raised from 1.18 to 12.66 when EDTA dosage increases from 0 to 2×10-3mol/L.Solution chemistry analyses show that EDTA is able to convert the Ca(OHA)2 hydrophobic precipitation on fluorite surface to a soluble Ca-EDTA complex but cannot complexly dissolve the Ce(OHA)3 precipitation on bastnaesite surface. Therefore, the Zeta potential of OHA conditioned fluorite can be reduced significantly by EDTA while the reduction degree to Zeta potential of bastnaesite is relatively low. XPS measurement shows that EDTA removes the chemically adsorbed OHA from fluorite surface but has little effect on the adsorbed OHA on bastnaesite surface. As a result, fluorite can be selectively depressed by EDTA in bastnaesite flotation, which behaves an important industrial application prospect in rare earth ore flotation.INTRODUCTIONNowadays, Rare earth elements (shortened as RE) and compounds are of significant importance for a range of rapidly expanding industrial applications including catalysis, metallurgy, renewable energy, and special materials due to their unique electrical, magnetic, optical and chemical properties [1]. The seventeen RE elements, including the lanthanide-group fifteen elements, yttrium and scandium, could be divided into three groups, i.e., light, medium and heavy RE elements based on the different solubility of RE sulfates [2]. Bastnaesite ((Ce,La)CO3), containing approximately 75% REO, is one of the most important light RE minerals [3]. Flotation is the common method to recover basetnaesite [4-6]. Nonetheless, basetnaesite is often associated with calcium-bearing gangue minerals such as fluorite, and the separation of basetnaesite and fluorite by flotation is usually difficult due to their similar surface properties and therefore floatability [7-9]. Therefore, research on high selective flotation reagents of bastnaesite over gangue minerals has attracted a lot of attention [10]."

Jan 1, 2018

By Alireza Javadi Nooshabadi, Kota Hanumantha Rao

Formation of hydrogen peroxide (H2O2), an oxidizing agent stronger than oxygen, by sulphide minerals during grinding was examined. It was found that pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite ((Zn, Fe) S), and galena (PbS) generated H2O2 in pulp liquid during wet grinding and also when the freshly ground solids are placed in water immediately after dry grinding. Pyrite produced more H2O2 than other minerals and the order of H2O2 production by the minerals was found to be pyrite > chalcopyrite > sphalerite > galena. The pH of the water influenced the extent of hydrogen peroxide formation with greater amounts of H2O2 produced at highly acidic pH. Furthermore, the effect of mixed sulphide minerals, i.e., pyrite-chalcopyrite, pyrite-galena, chalcopyrite-galena and sphalerite-pyrite, sphalerite-chalcopyrite and sphalerite-galena on the formation of H2O2 showed increasing H2O2 formation with increasing pyrite fraction. There is clear correlation of the amount of H2O2 production with the rest potential of the sulphide minerals; the greater the rest potential of a mineral the greater the formation of H2O2. This study highlights the necessity of revisiting the electrochemical and/or galvanic interactions between sulphide minerals, and interaction mechanisms between pyrite and other sulphide minerals in terms of their flotation behavior in the context of inevitable H2O2 existence in the pulp liquid.

Jan 1, 2014

By A. N. Zagorodnyaya

The results of research on recovery of ammonium perrhenate from by-products of lead production are presented in the article. For the first time in the world, rhenium marketable products were produced on lead plant of Kazakhstan. Distribution of rhenium in lead production has been studied. During oxidative agglomeration of lead charge, 67.43% rhenium is sublimated and at that, 67.27% rhenium is trapped by the dusts of a system of gas purification, out of them 6.21% is transferred into different solutions, 1.89% into slime and only 0.09% into exhaust. During agglomerate smelting, up to 72% of its rhenium is sublimated and condensed in the dusts also. At leaching stage of sulphate product under dusts processing by the method of sulphatization, 15% of its content in the dusts is transferred into solution. The sorption method on the ionite ?N-21 has been proposed for recovery of rhenium from the solutions of sulphatization. At the same time, rhenium recovery from the dusts into commodity was 13%. The method of direct hydrometallurgy - leaching the dusts by solutions of sulphuric acid under presence of manganous concentrates, has been proposed as alternative method of recovery. This method has allowed increasing recovery of rhenium and other metals from the dusts into solution up to 90%~95%. Rhenium solvent extraction by ??? has been proposed for recovery of rhenium from the leaching solutions. At that, extraction of rhenium into marketable product from the dusts is above 75%.

Jan 1, 2014

By B. Orberger, J. M. Milazzo, S. B. Blancher, J. Lützenkirchen, J. L. Dubos

"Industrial dusts are commonly agglomerated using empirical recipes with binders such as bentonite, while Sludges are agglomerated into mixes. Those materials contaminate the products, are expensive and generate significant amounts of slag. Achieving cold dust agglomeration with little or no binder requires understanding the controlling parameters in order to predict and optimize the process behavior. This in turn necessitates comprehensive dust characterization to base predictions on measurable characteristics. In the present work we collected 13 Mn-rich dusts over all the process chain: feed fines, smelting, and refining dusts, as well as ferromanganese alloy dust. This is the first systematic study of dusts along the Mn-processing chain for chemical, physical and mineralogical parameters. X-Ray Diffraction, Qemscan® and laser granulometry analyses show that the mineralogy, Particle Size Distribution (PSD) and morphology evolves from complex heterogenous to simple, homogenous along the process chain: The mineralogy of the primary ore dusts shows various hydroxides, oxides, carbonates, tectosilicates and phyllosilicates. The furnace dusts contain oxides, tectosilicates and carbonates with volatiles, while the refining dusts present only oxides and metal. Finally, the Metal dust is nearly pure metal. Particle morphologies and PSD vary from jagged, irregular particles with broad PSD (>1 mm to <0.3 µm) to smooth and spherical with narrow PSD (100 µm to <0.3 µm). The Metal dust is an exception with angular particles. The Cationic Exchange Capacities (CECs) of all samples range from 0 to 22 meq/100g. Specific surface areas (SSAs) range from <0.1 to 27m²/g, and seem to decrease with from ore feed to Metal dust. This may be due to the disappearance of hydrated and/or sheet-bearing minerals, since a smaller grain size usually implies an increased SSA. The zeta potential varies strongly over the range of the samples tested. However, beside the Gabon ore which has an Isoelectric Point (IEP) ~ 4.1, the other IEP ranges between 2 and 2.5."

Jan 1, 2018

By Anand Anupam

Conventionally, beneficiation in Indian coal washeries is done using dense medium cyclones upto the size of 0.5 mm. Coal fines below 0.5 mm size are extensively cleaned by froth flotation. There are many problems associated with flotation of Indian coals, e.g. poor response of coal particles to flotation, misplacement of fine high-ash material to froth, loss of good quality coarser coals (within ?0.5 mm size range) to tailing streams, high cost of reagents, water contamination, etc. In addition, sophisticated control systems for efficient management of the fines washing circuits are needed. Thus, there is an escalation in the capital and processing costs. In view of these facts, studies were carried out to establish the cleaning potential of dense medium cyclones for beneficiation of fine coal down to a size of 0.1 mm, essentially aimed at reducing the load on fine coal circuits mainly comprising of flotation. ROM Coal (in the size range of -2 + 0.1 mm) obtained from JogtaOCM,Jharia coalfield possessing relatively low ash (about 21%) was used in this study. Purpose for using low ash coal was to further lower, its ash content down to 8% which is comparable, to the ash content of imported coal. After characterization studies, nine tests were carried out on the prepared feed sample for its beneficiation using a dense medium cyclone of non-conventional design (very low cone angle and longer barrel), by varying its apex and vortex finder diameters. The efficiency of separation has been evaluated using Tromp curves. It could be established that it is possible to produce a clean coal of 8% ash, with Ep value of 0.044, using Jogta OCM coal by treating it in a modified dense medium cyclone. These results are summarized and discussed in detail in the present paper. Keywords: dense medium, cyclone, fine coal, beneficiation, Jharia coal

Sep 1, 2012

By V. A. Luganov

The processing of pyrite concentrates may be accomplished with a preliminary enrichment due to withdrawal of iron sulfides from initial concentrate. The withdrawal of iron sulfides is possible with the help of magnetic separation when the magnetic iron sulfides (pyrrhotites) separate from non-magnetic fraction?the sulfides of non-ferrous metals. The conversion of non-magnetic pyrite to magnetic pyrrhotites of adjusted structure occurs because of roasting with the withdrawal a part of sulfur. The resultant pyrrhotites are strong ferromagnetic with hexagonal structure. This paper contains results of studying magnetic properties of pyrrhotites, findings of the de-composition of initial pyrite with the consequence homogenizing of product and hardening of product of decomposition in liquid nitrogen. Define the type of pyrrhotites super lattice structure, was established that at increasing of sulfur contention the magnetic properties of pyrrhotites are change ? pyrrhotite begin evince the properties of antiferromagnetic material and magnetic susceptibility of material is interruptive changing from 0 to 1.7×10-3~1.9×10-3 SI units/g system. The paper contains results of technological researching of pyrrhotizing-magnetizing roasting of pyrite concentrates in different condition: in unoxidizing, with the decreasing contention of oxygen and in autogenous regime in air atmosphere. Established that the magnetic susceptibility of products depend of pyrite degree dissociation and achieve 2×10-3~3×10-3 SI units/g system at 40%~45% desulphurization. Defined the conditions of steady regime autogenous roasting, at resultant products possess coefficient of magnetization, and this can be used magnetic separation for separating ferromagnetic pyrrhotites from gangues and non-magnetic sulfides of non-ferrous metals. This technology of pyrrhotizing roasting is recommended for effecting in industrial condition. The initial materials and products of roasting subjected to chemical, thermogravimetric, Moss-bauer spectroscopy and X-ray analysis, defined the magnetic properties.

Jan 1, 2014

By L. X. Zeng

The low-grade nickel resource is very abundant in the western China. To make the best of the low grade nickel ore, we studied the process mineralogy and beneficiation process of nickel ore in the Yangliuping of Sichuan province. The grade of nickel is 0.45% in the nickel ore and the nickel exists in the sulfide including pyrrhotite, nickel pyrite, chalcopyrite primarily. The nickel distributes in pentlandite and magnetite over 90% and the copper does in the chalcopyrite over 95%. The carri-er minerals of useful elements tend to concentrate in space for concentration. As is shown in grain-size analysis of three major minerals, there are some more fine-grained grains with the percent of from 10% to 15% (<40 µm) and from 3.5% to 5.5% (<20 µm). So there will be some smaller size disseminated sulfide minerals difficulty to liberate in the process of concentration. The liberation degree of sulfide is not high and there are much associativity in the sulfides. Therefore, we should reclaim the sulfide aggregation dominating as pentlandite when concentrating. In addition, the sulphide minerals is so brittle that we should take care of preventing from crashing when grinding. The gangue mineral is mostly metamorphic mineral including serpentine, chlorite and amphibole which is easy to be argillization and difficult to concentrate.

Jan 1, 2014

By Y. S. Li

The life cycle assessment method is applied to investigate the environmental impacts of cop-per-slag and copper-ore concentration process. Some environmental load data of copper production are obtained. The result indicates that damage level of human health, ecosystem quality and re-sources respectively is 0.174, 0.0203, 0.246 in the copper-slag concentration and 0.112, 0.0136, 0.299 in the copper-ore concentration. Environmental impact of copper-slag production (0.44) is more than that of copper-ore production (0.42), but can meet the environmental protect demand. With domestic copper concentrate supply gap enlarging, recovering copper from slag will lead to a significant improving of resource utilization and development of circulation economics.

Jan 1, 2014

By Mike Daniel, Eric Wang

"Several new large copper and gold concentrators have been built and commissioned around the world in the past five to eight years. The success of the ramp-up from these very large concentrators has varied. CITIC SMCC Process Technology was engaged to assist some of these mines by gaining a better understanding of the factors that influence throughput capacity. As such, site-specific throughput forecast models that are influenced by SAG mill performance were developed. The forecast models are easy to interpret and modify and can greatly assist the mine management to make predictions and informed decisions for a range of site improvements. The models investigate the influence of SAG mill performance with respect to ore competency, derived from SMC Test® via the measured DWi model parameter. In some cases the benefits of blasting and from fine tuning milling operations are already incorporated into the "site-specific" forecast models. The methodology follows rigorous plant data analysis that is analogous to a "Mine-to-Mill®" optimisation project. The CITIC-SMCC model validation includes extensive data collection, which includes drill core analysis, ore characterisation and comprehensive comminution circuit operational data to assess the limitations within the comminution circuit within the operating mine. The results and models may be used to define the operating base lines of the processing areas and identify improvement opportunities upstream and downstream of the comminution circuit. The predictive capability of the models use logged production data and has enabled the user to differentiate between alternative circuit configuration options and identify optimum operating conditions. This approach minimises the ongoing requirement for costly plant surveys. The improvement strategy for each site, included the ongoing measurement of grindability, rock strength and via the Bond and SMC Test® respectively. Some commentary as to what other practitioners do with input data and their models is also presented as this highlights some of their shortcomings relative to the CITIC-SMCC methods."

Jan 1, 2014

By F. Ngoroma

Concentrators processing PGM bearing ores make use of polysaccharide depressants to reduce the recovery of the undesired naturally floatable gangue minerals, mainly silicates, present in the ore. Recent work has shown that high depressant dosages can completely depress naturally floatable gangue and thus prevent it from reporting to the concentrate. These high depressant dosages can, however, have a negative effect on the recovery of valuable minerals present in the ore by reducing the stability of the froth. In order to counterbalance the effects of depressant addition, frothers are added. It is, however, preferable to maintain independent control over bubble size and froth stability which is difficult to achieve with only one frother. An alternative strategy is, to use a blend of frothers, e.g. a weaker frother in combination with a stronger frother. Such a system allows an additional degree of freedom: changing the ratio of the two frothers, that would provide more independent control of bubble size and froth stability. This study demonstrates, through the use of batch flotation tests, how blending low molecular weight alcohols with commercially available frothers impact the solids and water recovery, as well as the valuable mineral recovery and concentrate grade in different PGM ores. Higher water and solids recoveries together with higher valuable mineral recoveries (>90% copper and >70% nickel) were obtained from tests using frother blends.

Sep 1, 2012

This study examines the surface alteration and flotation behaviour of synthetic moncheite, PtPd(BiTe)2, in the presence of pentlandite. The telluride minerals contribute around 20% ~ 30% and up to 45% of the PGM present in the Platreef ore and are considered to be slow floating as there is evidence of these minerals reporting to the tailings. It was proposed that oxidation products from other minerals and grinding media would affect the mineral surface composition and floatability thereby causing inadvertent depression of moncheite due to precipitating ions. ToF-SIMS analyses (time of flight secondary ion mass spectrometry) was used to characterise the mineral surface as well as the extent of surface alteration. Microflotation was used to deter-mine the hydrophobicity of the synthetic minerals. Conditioning of moncheite in the presence of pentlandite reduced the flotation response of the + 38 -106µm size fraction from > 99% to 56%. This was due to pentlandite dissolution products (iron and nickel hydroxy species) which formed overlayers on the mineral surfaces thereby inhibiting the adsorption of collector. In addition, further grinding of these samples, with and without pentlandite conditioning showed a negative effect on recovery due to the fineness of the particle size distribution and there was no advantage gained from any possible exposure of fresh sites in the sample.

Jan 1, 2014

By F. Boylu

In this study, Ca-bentonite was subjected to a series of systematic hydrocyclone tests with the aim of developing separation procedures and in turn achieving optimum recoveries. In hydrocyclone tests, vortex and apex diameters and also feed pressures were investigated. In each hydrocyclone set, vortex diameter was kept constant while the other two parameters varied to produce bentonites con-centrates of various smectite contents. The separation efficiencies were evaluated based on the cation exchange capacity (CEC), particle size and swelling index. The detailed hydrocyclone tests showed that, upgrading of Ca-bentonites require procedures different from the bentonites reported in the literature. Sodium and mixed bentonites are easy- to-disperse and easy-to-separate whereas calcium types need to be scrubbed rigorously for disintegration. Scrubbing properties of ca-bentonite were investigated as a function of scrubbing time and percent solids by weight (PS). The scrubbing conditions at 700 rpm for 1.5 hours and percent solids of 30 % were found more effective for achieving a better quality bentonite. In addition to the parameters mentioned above, the effect of percent solids on hydrocyclone separation was also studied. Although Ca-bentonites permit studying at higher percent solids, increasing solids content of the pulp deteriorated the quality of the clean products. Application of an appropriate separation scheme enabled the development of a unique separation procedure involving stage wise scrubbing followed by hydrocycloning which yielded calcium bentonite concentrates with CEC of 90 meq/100 g and high swelling indexes of 12 mL from the original bentonite of 65 meq/100 g and 7.0 mL, respectively. These results indicate that upgraded bentonite products can be conveniently used in various diverse industrial applications including bleaching earth, desiccant, cat litter, paper etc.

Jan 1, 2014

By M. Y. Zhou

The paper elaborates on the significance of producing ultra-low-moisture ore concentrate, the operating principle and technical features of thermocompression- filtration process, the kinetics involved in the dewatering process, and the technological process system and equipment used. It is pointed out that it is possible to reduce the moisture of fine ore concentrate to a minimum. By way of example, the case of the treatment of flotation molybdenum (Mo) using the thermocompression- filtration process is cited.

Jan 1, 2014

By P. Bevilacqua

In this paper the possibility to complete the copper recovery and to enrich in PVC a mixture of plastic granules obtained by grinding electrical cables are investigated. The recovery of a large part of the copper still present among the plastic granules was possible by means of a mechanical screening, the finer polymeric fraction was collected, at the same time. In order to complete the copper polymer separation the following techniques were employed. Counter current separation in water, static dense medium separation with zinc chloride solution and copper extraction with nitric acid and subsequent electrolytic deposition. A Tri-Flo® dynamic dense medium separator was employed in order to separate the lighter polymeric fraction, from the heavier polymeric fraction, mainly PVC. Water or a salt-water solution was employed to feed the separator device.

Jan 1, 2014

By P. Matias

The study involved two projects that will produce copper concentrate and may have their operations integrated. Transport by trucks, conveyor belt, and the equipment called RopeCon were evaluated as options for the ore transport between the sites. A rainforest stretch, that Vale S.A. demands to preserve, is situated between the projects. It was suggested to further review RopeCon because it presents minimal interactions with the environment. To design the preliminary system layout, a research was done on the rainforest cover height data, but the information found was scarce and imprecise. For preserving the local forest, the use of this data would conduct to the oversizing of RopeCon towers and, consequently, overestimation of its costs. For the acquisition of reliable information, a method was developed using local data acquired through airborne laser survey. The volume between the digital surface and terrain models was calculated to generate a surface representing the forest cover height. It was revealed, by plotting the points obtained from this surface, that 85% of the vegetation is below 25 m. This height is suggested to review the preliminary project with a more accurate design of the equipment towers, thus reducing its costs estimates. The method permits the precise location of the large trees, making easier to find a pathway, for linear-shaped facilities, that would minimize the creation of vegetation-free zones as a measure to protect equipments against falling trees and forest fires. Keywords: forest cover, mining projects facilities, digital models, airborne laser survey

Sep 1, 2012

By Tatyana A. Ivanova, Tamara N. Matveyeva, Anatoliy A. Fedorov, Tatyana V. Nedosekina, Valentin A. Chanturiya

An ingenious methodology purposively developed by the authors for comprehensive assessment of flotation properties, electrophysical characteristics and. crystal chemistry features of natural gold-bearing sulfide minerals of different origin has been used in this study. Examination of the elemental composition of the minerals, ion-molecular components of the liquid phase in suspensions, surface properties of sulfides and different flotation reagents sorption forms was performed using the methods of X-ray phase and spectral analysis, potentiometry, UV and IR spectrometry, computer image analysis, and computer simulation techniques. The role of isomorphous impurities in the formation of hydrophobic sulfhydric collector layers on mineral surfaces in complex ore processing has been elucidated. The parameters characterizing the variability of the Fe:S ratio in pyrite of different origin have been determined based on non-stoichiometry characteristics of natural gold-bearing sulfide crystals. An ingenious method of formatting and linear approximation of experimental data was used to find out the quantitative relationships between the impurity content, electrophysical characteristics, non-stoichiometry and floatability of pyrite from a number of different deposits. The effect of the impurity species present in sulfides on the characteristic pH value marking the floatability peaks as such and their trend of shift towards higher alkalinity has been revealed. A theoretical substantiation has been given to prognostic assessment criteria for processing characteristics of gold-bearing sulfide minerals with varying composition. New flotation reagents and advanced reagent systems which help to increase the contrast of processing characteristics for different gold-bearing sulfides, resulting in improved selectivity, have been developed. The mechanism of selective flotation of precious metal-bearing Fe and As sulfides achieved by using short-chain dithiocarbamates and a mixture of cyclic trithiocarbonate with oxyalkylsulfides has been analyzed.

Jan 1, 2003

By M. Etelapaa

A new approach to controlling the process of selective flotation of sulphide minerals from pyrite in a lime environment is covered in the presentation. Advantages of process control based on the electrochemical potential of slurry controlled by ?? ? electrode are proved and compared to conventional methods of ?? ? metering and conductometry. Keywords: flotation, electrochemical potential, automation dosing system, neural network

Sep 1, 2012

By M. D. Amirova

Cyanide-free technology of complex copper-lead ores flotation may be improved through enlarged range of pH values, enhanced copper recovery into copper concentrates due to additional recovery of secondary copper sulfides, as well as through enhanced efficiency of lead sulfides depression in process of new flotation modifiers-based selective separation. Study of the effects of flotation modifier (of metal nature) on minerals surface conditions proved that the xanthate is practically not adsorbed on the galenite surfaces due to minerals hydrophilization. Joint effects of sodium sulfite and modifier enhance process conditions for intensive galenite depression and at the same time for effective chalcopyrite and chalcosine flotation within a large pH values range (from pH=8 to pH=10). Identified mechanisms carry inference that proposed chemical reagent treating method is very promising for selective copper-lead concentrates separation. Potential use of carbon-containing materials as zinc flotation modifier to enhancing zinc recovery in processes of lead-zinc ores treatment has been studied. In our flotation tests we used Shalkiya (South Kazakhstan) lead-zinc ores containing such impurities as carbon shales, which presence impedes the process of saleable concentrates production and gives rise to excessive consumption of flotation agents due to the xanthate adsorption on the carbon. Lead and zinc concentrates were produced by process stages as follows: ores milled to 95% Cl. -0.074 +0; lead and zinc roughing flotation and further recleaner and testing operations. Test flotation in open process cycle resulted in enhancing zinc recovery into zinc concentrates by 21.1% and increasing zinc content in zinc concentrates by 3.96% that evidences promising potentialities for use of carbon-containing products as additional zinc flotation modifier. Works were carried out under National Program 2003~2005 of fundamental researches ?Physical and Chemical Mechanisms of Interactions in Multicomponent Solid and Liquid Systems Specific for Integrated Processing of Complex Metal-Containing Minerals and Technogenic Raw Materials? and contractual Agreement 2005 Optimization of Production and Technology of Shalkiya Lead-Zinc Ores Processing at Kentau Dressing Works.

Jan 1, 2014

By Janne Kauppi, Kaj Jansson, Piia Suvio, Saara Hagnäs

"Historically the focus at the mineral processing sites has been to improve the production operations, while little focus has been set on how factors, such as the quality of water used in the process affects the metal recovery. Simultaneously increasing public pressure and water scarcity is driving the mining industry to recycle more water back to the process, which in turn leads to accumulation of impurities within the recycled water. This paper presents a concept for a systematic approach on targeting the impurities that have a negative effect on the metal recovery at the flotation circuit by using a novel solution called Process Water Recycling Plant (PWRP). These plants are designed with specific ore type in mind. PWRP produces cost-effectively process water to different target qualities, especially for flotation purposes enabling higher and more stable flotation recovery. It consists of pre-designed and standard water treatment units for a wide range of volumes. The application-specific configuration of units is governed by the water quality requirements, and can be designed according to specific customer needs. Testing has been carried out in order to investigate, which recycling water impurities affect the different ore types and how the metal recovery in flotation is affected as a consequence of the poor-quality water. The results indicate that every ore type is impacted differently and without a good understanding on how the water quality impacts the process performance, adverse effects on the flotation recovery can occur.INTRODUCTION With a focus on where water is used within the mineral processing, it has become evident that even though water is used in several different processes, majority of the water losses within the site occur at the tailings processing and the tailings storage facility. New tailings management technologies that can increase the recovery of water are actively being developed, but the key to improving the efficiency of water use and reducing the operational risks lies in closing the water loops and increasing the slurry density in the tailings processing. With this shift from conventional tailings technologies towards paste and dry stacking, water efficiency is vastly improved, but it might in turn lead to process water challenges with impurities, reagents and fines being recycled and accumulated within the production processes."

Jan 1, 2018

By A. Shibayama

Soil contamination by organic compounds is one of the most concerned issues on polluted soil. It is well known that there are limited methods to remediate the contaminated soil on site. Especially, the in-situ method for contaminated soil is too difficult to de-contaminate the organic pollutant. In this study, the fundamental ability of soil remediation, which aimed to decrease oil concentration in, in-situ process, have been researched by using a high pressure gas generated from ?crush composition? on artificially oil contaminated soil. The n-hexadecane (n-C16H34) and other organic compounds were selected as soil oil contaminators, gravimetric analysis by soxhlet extraction and GC-MS were used as qualitative and quantitative analysing methods. For the experimental examination, the influences on the difference in the concentration of n-hexadecane (and other organics), the tamping amount, position and repetition of crush composition in soil, and scale (size) of experimental model were investigated. The n-hexadecane concentration reduced by the explosive effect of crush composition showed a reasonable decrease of about 30 wt%~60 wt% compared to the initial n-hexadecane. The removed amount of n-hexadecane and distance from explosion point of the crush composition was related in scale and model of contaminated soil.

Jan 1, 2014