Valentina InnocenziIda De MichelisFrancesco FerellaFrancesco Vegliò...
8页
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0085" view="all">The separation of yttrium and calcium from acid leach liquor obtained from leaching of fluorescent lamp phosphors has been investigated by solvent extraction with D2EHPA and Cyanex 272 in kerosene. The preliminary tests suggested that D2EHPA was more efficient than Cyanex 272 for separation of yttrium. The experimental tests allowed to define the best process conditions, among those investigated, to separate and recover yttrium selectively. The best separation circuit included three-stage cross current extraction with 20%v/v D2EHPA in kerosene (O/A=1/1, room temperature, 10 min of contact, pH 0.02) and stripping step in counter current with 1.5M sulfuric acid (O/A=1/1, room temperature, 30min of contact). After stripping, yttrium was recovered as oxalate by the addition of oxalic acid. According to the experimental results, a hydrometallurgical process was developed. The final recovery from leach liquor was around 90% and the grade of the final product was 97.5% as hydrated yttrium oxalate. The main impurity was sulfur, 1.28% wt, in addition to traces of other elements such as Si (0.057% wt), Zn (0.015% wt), Eu (0.14% wt) and Fe (0.02% wt).</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0010">Highlights</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0090" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">The paper is focused on recovery of yttrium from fluorescent lamp phosphors.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">Yttrium was separated from calcium, the main impurity, by solvent extraction.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">D2EHPA was more effective than Cyanex 272 in extraction of yttrium.</ce:para></ce:list-item><ce:list-item id="li0020"><ce:label>?</ce:label><ce:para id="p0020" view="all">The overall recovery of yttrium from leach liquor was around 90%.</ce:para></ce:list-item><ce:list-item id="li0025"><ce:label>?</ce:label><ce:para id="p0025" view="all">Grade of the final product was 97.5% as hydrated yttrium oxalate.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0065" view="all">A systematic study of diasporic bauxite flotation using commercial oleic acids with different iodine values as collector was conducted in this paper. Bench scale flotation tests for diasporic bauxite ore and micro-flotation tests for relevant pure minerals (including diaspore, pyrophyllite and kaolinite) were carried out at different conditions using commercial oleic acids with iodine values of 65, 121 and 131. The results suggest that an increase in the iodine value of oleic acid would lead to improved flotation separation of diaspore from aluminosilicates. Use of the commercial oleic acid with iodine value of 131 in closed-circuit flotation tests allowed us to obtain a concentrate with alumina-to-silica (A/S) ratio of 5.33 and alumina recovery of 85.56% from the feed ore (A/S ratio=3.39). Chemical analyses of these commercial oleic acids found that an increase in the iodine value was associated with increased proportion of linoleic acid in the commercial oleic acids. To fundamentally understand the correlation between the iodine value of commercial oleic acids and the efficiency of flotation separation of diaspore from aluminosilicates, the computational studies of frontier molecular orbital energy of oleic and linoleic acid were done, and the results suggest that linoleic acid has higher chemical activity than oleic acid and its chemical adsorption on diaspore is more stable than that of oleic acid.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0010">Highlights</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0070" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">Oleic acids with different iodine value were used for bauxite flotation.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">Organic species in oleic acids with different iodine value were analyzed.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">Frontier molecular orbital energy of oleic and linoleic acid were calculated.</ce:para></ce:list-item><ce:list-item id="li0020"><ce:label>?</ce:label><ce:para id="p0020" view="all">Linoleic acid has small frontier orbital energy high activity than oleic acid.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0080" view="all">The utilization of abundant low-grade iron ores is potentially important to many countries in the word, especially to China. These iron ores contain many detrimental impurities and are difficult to upgrade to make suitable concentrates for the blast furnace. In this paper, the beneficiation of a low-grade hematite ore fines containing carbonates with magnetization roasting and magnetic separation was proposed and studied. The hematite and siderite are almost completely converted into magnetite by 8wt% coal at roasting temperature of 800°C for 8min. Under the optimized conditions, a high grade magnetic concentrate containing 65.4wt% iron with an iron recovery of 92.7% was achieved. Meanwhile, the effects of roasting temperature, reaction time and coal to ore ratio on the magnetic properties of roasted materials were investigated using a vibration sample magnetometer (VSM). The results show that the magnetic susceptibility and magnetism saturation of hematite ore can be highly increased due to the selective conversion of hematite and siderite into magnetite caused by magnetization roasting which facilitates their separation from non-magnetic minerals.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="graphical" xml:lang="en" view="all"><ce:section-title id="st0010">Graphical abstract</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para>Display Omitted</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0015" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0015">Highlights</ce:section-title><ce:abstract-sec id="as0015" view="all"><ce:simple-para id="sp0090" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">The beneficiation of a hematite ore fines with magnetization roasting and magnetic separation was proposed and studied.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">The magnetic properties of ore can be enhanced due to the selective conversion of hematite and siderite into magnetite.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">Magnetization roasting can be applied effectively for the processing of carbonate-containing hematite ore.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
Arif Tirto AjiJari AromaaBenjamin P. WilsonMari Lundstr?m...
7页
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0085" view="all">In electrorefining, Group 15 impurities arsenic, antimony and bismuth, may precipitate within the bulk electrolyte as floating slimes and contaminate the copper cathodes. In order to determine the impurity specific thresholds related to the formation of suspended solids, synthetic copper electrorefining electrolytes with different concentrations of arsenic, antimony and bismuth were investigated by a continuous filtration method. The amount and composition of the floating slimes obtained were evaluated in terms of the initial impurity concentrations present in the synthetic electrolyte. As a result, the specific influence of arsenic, antimony and bismuth on the floating slime formation was ascertained. The results suggest that there is an upper limit in electrorefining electrolytes for antimony (Sb) of 800mg/L for floating slime formation, although the limit for Bi was less clear. Furthermore, the structure of the synthetic floating precipitates produced were analyzed using both SEM-EDS and XRD and showed typical amorphous structure of floating slimes with particle size of approximately 25μm and predicted composition of BiAsO<ce:inf loc="post">4</ce:inf>, SbAsO<ce:inf loc="post">4</ce:inf>, Sb<ce:inf loc="post">2</ce:inf>O<ce:inf loc="post">3</ce:inf>and Bi<ce:inf loc="post">2</ce:inf>O<ce:inf loc="post">3</ce:inf>.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0010">Highlights</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0090" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">Floating slime formation is significantly affected by antimony concentration in electrolyte</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">Results suggest a threshold limit of [Sb] ≥800 mg/L for floating slime formation.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">As concentration in the electrolyte influences the level of antimony arsenate in the floating slime.</ce:para></ce:list-item><ce:list-item id="li0020"><ce:label>?</ce:label><ce:para id="p0020" view="all">Bi concentration in the precipitate is independent of Bi solution concentration and can result from the adsorption of Bi oxide on other floating compounds.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0050" view="all">As an experimental study, the research in this paper was conducted to illustrate the influence of solids content and composition of cemented paste backfill (CPB) on the material's rheological and mechanical characteristics. A new type of CPB was used in this research, which was composed of waste rock as coarse aggregates, fly ash as fines, lime slag as activator proportions and ordinary Portland cement as binder. The mechanical strength of CPB improved significantly with an increase in the solids content, but the workability decreased because the water content decreased. When the solids content was 75% by weight (wt.%), the slump value was 165mm, which met the requirement for pumping. At a solids content of 75%, the CPB also had an unconfined compressive strength (UCS) of 1.83MPa, tensile strength of 0.401MPa, and Poisson's ratio of 0.136 at a curing time of 28days. Increasing the fly ash proportion caused the workability and mechanical strength of the CPB to increase until they reached maximum values, at which point subsequent increases caused the values to decrease. The workability of CPB reached its peak when fly ash proportion was 35wt.%, and the mechanical strength reached its peak at 45wt.%. The workability of CPB decreased as the lime slag proportion increased. The strength of CPB also increased with an increase in the lime slag proportion, however, only until it reached 12wt.%, at which point the strength began to decline. The addition of more cement resulted in much better mechanical performance of the CPB samples, especially with longer curing times. However, workability of CPB increased as cement portion increased in the range of 0% to 2.5%, before decreasing over the range of 2.5%–5.0%.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0010">Highlights</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0055" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">A new cemented paste backfill (CPB) composed by waste materials was presented.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">How the factors influence rheological and mechanical properties of CPB was studied.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">Non-contact digital photogrammetry method was used to test Poisson's ratio of CPB.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
Grant R. BallantyneBenjamin BonfilsMalcolm S. Powell
10页
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0080" view="all">Accurate characterisation of ore competence through controlled single particle impact can enable improved modelling of comminution process response to ore variability. A simple relationship is presented to relate the energy input and feed particle size to the breakage progeny with two fitting parameters. Previous techniques have focused either on low energy repeated impacts or high energy single impacts and have been applied over relatively small ranges of particle sizes. The method presented builds on previous understanding to unite these two disparate fields on feed particle sizes over more than two orders of magnitude. The method has been tested on 5 ores from 37.5mm to 250μm over energies from 0.02 to 3.5kWh/t. The resultant standard error of 3.3% is lower than other benchmarked models, with considerably fewer fitting parameters and no use of splining functions required. The direct calculation of appearance function for any feed size and input energy renders the proposed model well suited to incorporation in comminution process models. Further testing is required on additional ores, and further interpretation is required to obtain mechanistic explanations for the empirical fits to the model parameters.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="graphical" xml:lang="en" view="all"><ce:section-title id="st0010">Graphical abstract</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para id="sp0085" view="all">Example of the model relationship between feed particle size and percentage passing<ce:italic>t<ce:inf loc="post">1.2</ce:inf></ce:italic>(probability of breakage) and<ce:italic>t<ce:inf loc="post">10</ce:inf></ce:italic>(traditional degree of breakage).</ce:simple-para><ce:simple-para>Display Omitted</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0015" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0015">Highlights</ce:section-title><ce:abstract-sec id="as0015" view="all"><ce:simple-para id="sp0090" view="all"><ce:list id="l0005"><ce:list-item id="li1005"><ce:label>?</ce:label><ce:para id="p1005" view="all">A new two-parameter model is presented to fully describe the progeny size resulting from single sided impact breakage.</ce:para></ce:list-item><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">An accurate fit is achieved on 5 ores over a wide range of sizes and energies –0.25 to 37.5mm and 0.02 to 3.5kWh/t.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">This approach provides a link between low energy, probability of breakage and high energy, t<ce:inf loc="post">10</ce:inf>models.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">This technique reduced the number of model parameters from 18 to 2 or 3 and halved the average standard error to 3.3%.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
查看更多>>摘要：<![CDATA[<ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0005" xml:lang="en" view="all" class="author"><ce:section-title id="st0005">Abstract</ce:section-title><ce:abstract-sec id="as0005" view="all"><ce:simple-para id="sp0070" view="all">Coal desulfurization is imperative to creating clean coal and reducing harmful emissions during the burning process. Due to the lack of effective technology in the field of fine coal dry separation, a novel microwave-enhanced magnetic property processing method was demonstrated in this manuscript. Using representative simulated minerals, the response and absorption characteristics of coal pyrite were intuitively demonstrated while analyzing the selective absorption mechanisms of different minerals in fine coal. Results show that the coal pyrites from Inner Mongolia were reduced by approximately 20% after 60s of microwave treatment, and 60% after 90s. The binding energy and chemical shift were quite large when the oxidation state was high. Fe<ce:sup loc="post">2+</ce:sup>and troilite FeS were oxidized to Fe<ce:inf loc="post">2</ce:inf>O<ce:inf loc="post">3</ce:inf>after 60s microwave treatment, and to Fe<ce:sup loc="post">3+</ce:sup>after 90s. Dynamic equilibrium was reached after 3min of microwave treatment. The conversion rate was lower for pyrite to pyrrhotite than for pyrrhotite to troilite. The conversion of pyrrhotite to troilite appeared to be sensitive to the amount of microwave treatment. The specific susceptibility dropped rapidly and was nearly an order of magnitude greater than the raw coal. This study indicates a high possibility for coal desulfurization through this dry method enhanced with microwave energy.</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0010" class="graphical" xml:lang="en" view="all"><ce:section-title id="st0010">Graphical abstract</ce:section-title><ce:abstract-sec id="as0010" view="all"><ce:simple-para>Display Omitted</ce:simple-para></ce:abstract-sec></ce:abstract><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns="http://www.elsevier.com/xml/ja/dtd" id="ab0015" class="author-highlights" xml:lang="en" view="all"><ce:section-title id="st0015">Highlights</ce:section-title><ce:abstract-sec id="as0015" view="all"><ce:simple-para id="sp0080" view="all"><ce:list id="l0005"><ce:list-item id="li0005"><ce:label>?</ce:label><ce:para id="p0005" view="all">Microwave-enhanced magnetic property process proposed for coal desulfurization.</ce:para></ce:list-item><ce:list-item id="li0010"><ce:label>?</ce:label><ce:para id="p0010" view="all">Networker analyzer used to analyze pyrite response and absorption characteristics.</ce:para></ce:list-item><ce:list-item id="li0015"><ce:label>?</ce:label><ce:para id="p0015" view="all">XPS was used to study combined states and surface chemical analysis of coal.</ce:para></ce:list-item></ce:list></ce:simple-para></ce:abstract-sec></ce:abstract>]]>
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