Pub Date : 2024-12-21DOI: 10.1016/j.mineng.2024.109163
Yusheng Du , Qingyou Meng , Chong Han , Zhitao Yuan , Lixia Li , Jiwei Lu , Ting Liu
In this work, acid surface pretreatment improved the selective dispersion between micro-fine titanaugite (−19 μm) and ilmenite particles in pulp. Microflotation experiments showed that as the mass percentage of micro-fine titanaugite in mixed ore increased, the separation index in ilmenite flotation decreased due to micro-fine titanaugite adsorbed on ilmenite surfaces, while acid surface pretreatment weakened this adverse effect. Turbidity, optical microscope, SEM-EDS, and EDLVO theory analyses suggested that after acid surface pretreatment, these aggregations between ilmenite particles and between titanaugite particles reinforced, and they were related to the decreased surface hydrophilicity of ilmenite and the formative calcium precipitate on titanaugite surfaces, respectively. Meanwhile, the difference in surface hydrophilicity of out-of-phase particles increased. These variations between particles led to a reduction in aggregation between out-of-phase particles. AFM adhesive force analysis proved that after acid surface pretreatment, the adhesion between micro-fine titanaugite and ilmenite particles decreased, and it was lower than the increased adhesion between in-phase particles. A greater improvement in selective dispersion between out-of-phase particles treated with acid surface pretreatment occurred in pulp, further enhancing the flotation index of ilmenite.
{"title":"The mechanism of selective dispersion between micro-fine titanaugite and ilmenite particles caused by acid surface pretreatment in pulp","authors":"Yusheng Du , Qingyou Meng , Chong Han , Zhitao Yuan , Lixia Li , Jiwei Lu , Ting Liu","doi":"10.1016/j.mineng.2024.109163","DOIUrl":"10.1016/j.mineng.2024.109163","url":null,"abstract":"<div><div>In this work, acid surface pretreatment improved the selective dispersion between micro-fine titanaugite (−19 μm) and ilmenite particles in pulp. Microflotation experiments showed that as the mass percentage of micro-fine titanaugite in mixed ore increased, the separation index in ilmenite flotation decreased due to micro-fine titanaugite adsorbed on ilmenite surfaces, while acid surface pretreatment weakened this adverse effect. Turbidity, optical microscope, SEM-EDS, and EDLVO theory analyses suggested that after acid surface pretreatment, these aggregations between ilmenite particles and between titanaugite particles reinforced, and they were related to the decreased surface hydrophilicity of ilmenite and the formative calcium precipitate on titanaugite surfaces, respectively. Meanwhile, the difference in surface hydrophilicity of out-of-phase particles increased. These variations between particles led to a reduction in aggregation between out-of-phase particles. AFM adhesive force analysis proved that after acid surface pretreatment, the adhesion between micro-fine titanaugite and ilmenite particles decreased, and it was lower than the increased adhesion between in-phase particles. A greater improvement in selective dispersion between out-of-phase particles treated with acid surface pretreatment occurred in pulp, further enhancing the flotation index of ilmenite.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109163"},"PeriodicalIF":4.9,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-21DOI: 10.1016/j.mineng.2024.109159
Dezhi Liu , Yangyang Huai , Rui Liao , Binbin Li , Lingming Zeng
During the serpentine-contained sulfide ores flotation process, the presence of serpentine slimes will intensively deteriorate the flotation performance of sulfide ores due to hetero-coagulation. To handle this issue, tetrapotassium pyrophosphate (TKPP) was used as a novel depressant in this work. Micro-flotation results revealed that the addition of 5 g/L fine serpentine particle (−10 µm) caused a substantial reduction of approximately 82.5 % in pyrite recovery at pH 9. However, the detrimental impact of fine serpentine could be efficiently mitigated by the application of 30 mg/L TKPP, with a marked increase in pyrite recovery from 10.15 % to 91.25 %. The underlying mechanisms were elucidated using various characterization methods, revealing a significant shift in the surface charge of serpentine from positive to negative upon the addition of 30 mg/L TKPP, while the surface charge of pyrite remained largely unchanged. Consequently, a well-dispersion state of the mixed minerals pulp was achieved due to the identical surface charge. The alteration mechanisms of TKPP on serpentine involved the selective adsorption through forming P-O-Mg bonds and the accelerated decomposition of Mg2+ from serpentine. This study highlights the promising role of TKPP in reducing Mg in sulfide concentrator, proving a feasible solution for sulfide beneficiation operations.
{"title":"Enhancement mechanisms of tetrapotassium pyrophosphate on flotation separation of pyrite from fine serpentine","authors":"Dezhi Liu , Yangyang Huai , Rui Liao , Binbin Li , Lingming Zeng","doi":"10.1016/j.mineng.2024.109159","DOIUrl":"10.1016/j.mineng.2024.109159","url":null,"abstract":"<div><div>During the serpentine-contained sulfide ores flotation process, the presence of serpentine slimes will intensively deteriorate the flotation performance of sulfide ores due to hetero-coagulation. To handle this issue, tetrapotassium pyrophosphate (TKPP) was used as a novel depressant in this work. Micro-flotation results revealed that the addition of 5 g/L fine serpentine particle (−10 µm) caused a substantial reduction of approximately 82.5 % in pyrite recovery at pH 9. However, the detrimental impact of fine serpentine could be efficiently mitigated by the application of 30 mg/L TKPP, with a marked increase in pyrite recovery from 10.15 % to 91.25 %. The underlying mechanisms were elucidated using various characterization methods, revealing a significant shift in the surface charge of serpentine from positive to negative upon the addition of 30 mg/L TKPP, while the surface charge of pyrite remained largely unchanged. Consequently, a well-dispersion state of the mixed minerals pulp was achieved due to the identical surface charge. The alteration mechanisms of TKPP on serpentine involved the selective adsorption through forming P-O-Mg bonds and the accelerated decomposition of Mg<sup>2+</sup> from serpentine. This study highlights the promising role of TKPP in reducing Mg in sulfide concentrator, proving a feasible solution for sulfide beneficiation operations.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109159"},"PeriodicalIF":4.9,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ironmaking- steelmaking is a material and energy intensive process with a resource efficiency of only ∼ 33 %. Resource efficiency enhancement requires recovering the wasted/unutilized material by-products and the energy associated with them in various forms. This review attempts to identify the material leakages and energy losses at each step of steelmaking (from iron ore mining) and explores approaches to plug the energy and material leakage; material efficiency brings in energy savings indirectly. Besides the material loss, accumulation of the by-products (slime/tailings, steel slag, etc.), carbon emission, etc., cause environmental and ecological damage. The review discusses the prospects of slimes/tailings beneficiation through physical and physicochemical methods (often after some pretreatments). The manuscript also discusses the need to recover heat from molten slags (BF slag and BOF slag) to reduce the energy intensity. Further, it discusses the endeavors to overcome the latent hydraulic activity of granulated BF slag and ways to enhance the acceptability of BOF slag in different applications. A brief sum-up of global efforts towards net zero emission (in line with the Paris Declaration) through carbon recycling, low emission intensity processes, alternate fuels, etc., is included. Lastly, the authors list the challenges of the Indian iron & steel industry and the efforts from the government and steel industries towards achieving the projected crude steel production (300 million tons) without crossing the emission intensity thresholds (Paris Declaration). The endeavors strengthen the sustainability of the steel industry.
{"title":"Avenues of resources efficiency enhancement in iron and steel production","authors":"T.C. Alex, Rashmi Singla, D.P. Sahoo, K.D. Mehta, Sanjay Kumar","doi":"10.1016/j.mineng.2024.109160","DOIUrl":"10.1016/j.mineng.2024.109160","url":null,"abstract":"<div><div>Ironmaking- steelmaking is a material and energy intensive process with a resource efficiency of only ∼ 33 %. Resource efficiency enhancement requires recovering the wasted/unutilized material by-products and the energy associated with them in various forms. This review attempts to identify the material leakages and energy losses at each step of steelmaking (from iron ore mining) and explores approaches to plug the energy and material leakage; material efficiency brings in energy savings indirectly. Besides the material loss, accumulation of the by-products (slime/tailings, steel slag, etc.), carbon emission, etc., cause environmental and ecological damage. The review discusses the prospects of slimes/tailings beneficiation through physical and physicochemical methods (often after some pretreatments). The manuscript also discusses the need to recover heat from molten slags (BF slag and BOF slag) to reduce the energy intensity. Further, it discusses the endeavors to overcome the latent hydraulic activity of granulated BF slag and ways to enhance the acceptability of BOF slag in different applications. A brief sum-up of global efforts towards net zero emission (in line with the Paris Declaration) through carbon recycling, low emission intensity processes, alternate fuels, etc., is included. Lastly, the authors list the challenges of the Indian iron & steel industry and the efforts from the government and steel industries towards achieving the projected crude steel production (300 million tons) without crossing the emission intensity thresholds (Paris Declaration). The endeavors strengthen the sustainability of the steel industry.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109160"},"PeriodicalIF":4.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.mineng.2024.109161
Yan Miao, Guangke Ye, Binbin Li, Hong Zheng, Guofan Zhang
Pyrite is the most abundant metallic sulphide ore in nature and has semiconducting properties that induce electrochemical reactions. Scholars have conducted many related electrochemical studies, but studies on the unconventional environment with low dissolved oxygen (DO) in high altitude area are relatively few. In this study, we have designed and built a high altitude simulation test platform, investigated the electrochemical property changes of pyrite, analyzed the form of DO interaction pattern by DFT calculations, and studied the interface properties of the pyrite by XPS and SEM-EDS. We found DO takes away the H atoms from the water molecules on the pyrite surface and promotes hydroxylation by DFT calculations. The DO content in the flotation slurry at high altitude areas is lower due to low air pressure. Under the weakly alkaline (pH = 8.5) condition, the surface corrosion rate is lower at high altitude condition, which is favorable to the formation of the S0 deactivation layer, which improves the hydrophobicity of the pyrite surface and makes it easier to adsorb fine particles. The study provides a theoretical basis for the pH-DO value adjustment technique for sulphide ore flotation and also provides guidance for the regulation of pyrite surface wettability at high altitude areas.
{"title":"Electrochemical and interfacial studies on the oxidation of pyrite at high altitude area","authors":"Yan Miao, Guangke Ye, Binbin Li, Hong Zheng, Guofan Zhang","doi":"10.1016/j.mineng.2024.109161","DOIUrl":"10.1016/j.mineng.2024.109161","url":null,"abstract":"<div><div>Pyrite is the most abundant metallic sulphide ore in nature and has semiconducting properties that induce electrochemical reactions. Scholars have conducted many related electrochemical studies, but studies on the unconventional environment with low dissolved oxygen (DO) in high altitude area are relatively few. In this study, we have designed and built a high altitude simulation test platform, investigated the electrochemical property changes of pyrite, analyzed the form of DO interaction pattern by DFT calculations, and studied the interface properties of the pyrite by XPS and SEM-EDS. We found DO takes away the H atoms from the water molecules on the pyrite surface and promotes hydroxylation by DFT calculations. The DO content in the flotation slurry at high altitude areas is lower due to low air pressure. Under the weakly alkaline (pH = 8.5) condition, the surface corrosion rate is lower at high altitude condition, which is favorable to the formation of the S<sup>0</sup> deactivation layer, which improves the hydrophobicity of the pyrite surface and makes it easier to adsorb fine particles. The study provides a theoretical basis for the pH-DO value adjustment technique for sulphide ore flotation and also provides guidance for the regulation of pyrite surface wettability at high altitude areas.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109161"},"PeriodicalIF":4.9,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Printed circuit board (PCB) assemblies constitute a concentrated source of valuable metals. This study evaluates the performance of a complete hydrometallurgical process for extracting and recovering rare earth elements (REE), Cu, Ni, Ag and Au from leachates produced from PCB found in smartphones via four selective leaching steps. In a REE leachate ([Dy] = 43 mg/L, [Gd] = 5 mg/L, [Nd] = 266 mg/L, [Sm] = 35 mg/L, [Tb] = 8 mg/L, [Ho] = 2 mg/L), 92 % of REE was precipitated at room temperature with H2C2O4/REE molar ratio of 2/1. Calcination of the REE-oxalate precipitates at 800 °C resulted in a mixture of rare earth oxides (REO) with a 91 % purity. From the base metal leachate ([Cu] = 19,376 mg/L and [Ni] = 1,264 mg/L), Cu was electrodeposited during 120 min (pH = 3, current 270 A/m2) while Ni was precipitated by addition of oxalic acid (H2C2O4/Ni molar ratio of 2/1, pH 4.4, T = 60 °C, t = 60 min), followed by calcination at 600 °C for 4 h to form NiO (93 % purity). Three oxidative leaching steps (10 % w/v solids, T = 80 °C, t = 180 min, 1.0 M H2SO4, 67 g H2O2/L, T = 80 °C, t = 180 min) solubilized 97 % of Ag. Subsequently, with the addition of Cu (Cu/Ag mass ratio of 2), at room temperature and 120 min, Ag was precipitated 99.4 % in the first leachate ([Ag] = 488 mg/L). A Zn/Au mass ratio of 30 precipitated 99.1 % of gold at the room-temperature from the gold leachate ([Au] = 107 mg/L).
{"title":"Leaching and recovery of rare earth elements, copper, nickel, silver and gold from used smartphone circuit boards","authors":"Salmata Diallo , Lan-Huong Tran , Dominic Larivière , Jean-François Blais","doi":"10.1016/j.mineng.2024.109157","DOIUrl":"10.1016/j.mineng.2024.109157","url":null,"abstract":"<div><div>Printed circuit board (PCB) assemblies constitute a concentrated source of valuable metals. This study evaluates the performance of a complete hydrometallurgical process for extracting and recovering rare earth elements (REE), Cu, Ni, Ag and Au from leachates produced from PCB found in smartphones via four selective leaching steps. In a REE leachate ([Dy] = 43 mg/L, [Gd] = 5 mg/L, [Nd] = 266 mg/L, [Sm] = 35 mg/L, [Tb] = 8 mg/L, [Ho] = 2 mg/L), 92 % of REE was precipitated at room temperature with H<sub>2</sub>C<sub>2</sub>O<sub>4</sub>/REE molar ratio of 2/1. Calcination of the REE-oxalate precipitates at 800 °C resulted in a mixture of rare earth oxides (REO) with a 91 % purity. From the base metal leachate ([Cu] = 19,376 mg/L and [Ni] = 1,264 mg/L), Cu was electrodeposited during 120 min (pH = 3, current 270 A/m<sup>2</sup>) while Ni was precipitated by addition of oxalic acid (H<sub>2</sub>C<sub>2</sub>O<sub>4</sub>/Ni molar ratio of 2/1, pH 4.4, T = 60 °C, t = 60 min), followed by calcination at 600 °C for 4 h to form NiO (93 % purity). Three oxidative leaching steps (10 % w/v solids, T = 80 °C, t = 180 min, 1.0 M H<sub>2</sub>SO<sub>4</sub>, 67 g H<sub>2</sub>O<sub>2</sub>/L, T = 80 °C, t = 180 min) solubilized 97 % of Ag. Subsequently, with the addition of Cu (Cu/Ag mass ratio of 2), at room temperature and 120 min, Ag was precipitated 99.4 % in the first leachate ([Ag] = 488 mg/L). A Zn/Au mass ratio of 30 precipitated 99.1 % of gold at the room-temperature from the gold leachate ([Au] = 107 mg/L).</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109157"},"PeriodicalIF":4.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1016/j.mineng.2024.109158
Guihua Zheng , Zhe Yang , Kangkang Sun , Hongguang Lv , Liqiang Ma
Particle shape plays a crucial role in mineral processing and is largely influenced by grinding. However, traditional descriptions of particle shape using circularity are often inadequate to reveal the grinding mechanism. This study applied a new aspect ratio (AR)-modified roundness to quantify particle shape. The shape of anthracite particle as a function of different grinding conditions was analyzed using AR-modified roundness in comparison with circularity. Statistical analysis of the t-test was used to validate the data reliability. The results indicated that AR-modified roundness provides a more comprehensive and accurate characterization of particle shape and evaluation of abrasion mechanism. Additionally, the grinding media and grinding time influence the shape of particles across different size fractions in the milled products, highlighting the intricate interplay between these factors. This paper offers insights on optimizing grinding processes to improve processing efficiency by exploring how milling conditions influence particle shape.
{"title":"Effect of grinding media, time, and particle size on coal particle shape: Interpretation of aspect ratio-modified roundness for products of ball and rod mills","authors":"Guihua Zheng , Zhe Yang , Kangkang Sun , Hongguang Lv , Liqiang Ma","doi":"10.1016/j.mineng.2024.109158","DOIUrl":"10.1016/j.mineng.2024.109158","url":null,"abstract":"<div><div>Particle shape plays a crucial role in mineral processing and is largely influenced by grinding. However, traditional descriptions of particle shape using circularity are often inadequate to reveal the grinding mechanism. This study applied a new aspect ratio (AR)-modified roundness to quantify particle shape. The shape of anthracite particle as a function of different grinding conditions was analyzed using AR-modified roundness in comparison with circularity. Statistical analysis of the <em>t</em>-test was used to validate the data reliability. The results indicated that AR-modified roundness provides a more comprehensive and accurate characterization of particle shape and evaluation of abrasion mechanism. Additionally, the grinding media and grinding time influence the shape of particles across different size fractions in the milled products, highlighting the intricate interplay between these factors. This paper offers insights on optimizing grinding processes to improve processing efficiency by exploring how milling conditions influence particle shape.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109158"},"PeriodicalIF":4.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1016/j.mineng.2024.109155
Taotao Sun , Mian M. Ahson Aslam , Guangquan Chen , Changsheng Peng
In this study, the pyrolytic reduction of iron oxides contained in red mud using biomass-derived reductive gases was explored. Wheat straw and rice husk were evaluated together with activated carbon and graphite for their effectiveness in converting iron oxides to magnetite. Thermodynamic analyses using thermogravimetric-mass spectrometry (TG-MS) demonstrated that CO, H2, CH4, and biochar could effectively reduce iron oxides, with CO being particularly effective at lower temperatures. Optimal parameters for iron recovery were identified through an orthogonal experimental design, highlighting wheat straw as the superior biomass feedstock due to its high yield of reducing gases and fast reduction kinetics. Single-factor optimization emphasized the importance of temperature and red mud-to-biomass ratio. Optimization of pyrolytic reduction conditions revealed that wheat straw achieved the highest iron recovery rate of 75 % and a concentrate grade of 42 % at 550 °C, with a red mud-to-wheat straw ratio of 1:2, a heating rate of 12 °C/min, and a reduction time of 40 min. Mechanistic studies using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy showed hematite in red mud transforming into magnetite, with some aluminum atoms substituting for iron to form iron-aluminum spinel, impacting the concentrate grade. This is a promising method for recycling iron from red mud, mitigating environmental impact, and conserving resources.
{"title":"Low-temperature biomass pyrolytic reduction and recovery of iron oxides from red mud","authors":"Taotao Sun , Mian M. Ahson Aslam , Guangquan Chen , Changsheng Peng","doi":"10.1016/j.mineng.2024.109155","DOIUrl":"10.1016/j.mineng.2024.109155","url":null,"abstract":"<div><div>In this study, the pyrolytic reduction of iron oxides contained in red mud using biomass-derived reductive gases was explored. Wheat straw and rice husk were evaluated together with activated carbon and graphite for their effectiveness in converting iron oxides to magnetite. Thermodynamic analyses using thermogravimetric-mass spectrometry (TG-MS) demonstrated that CO, H<sub>2</sub>, CH<sub>4</sub>, and biochar could effectively reduce iron oxides, with CO being particularly effective at lower temperatures. Optimal parameters for iron recovery were identified through an orthogonal experimental design, highlighting wheat straw as the superior biomass feedstock due to its high yield of reducing gases and fast reduction kinetics. Single-factor optimization emphasized the importance of temperature and red mud-to-biomass ratio. Optimization of pyrolytic reduction conditions revealed that wheat straw achieved the highest iron recovery rate of 75 % and a concentrate grade of 42 % at 550 °C, with a red mud-to-wheat straw ratio of 1:2, a heating rate of 12 °C/min, and a reduction time of 40 min. Mechanistic studies using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy showed hematite in red mud transforming into magnetite, with some aluminum atoms substituting for iron to form iron-aluminum spinel, impacting the concentrate grade. This is a promising method for recycling iron from red mud, mitigating environmental impact, and conserving resources.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109155"},"PeriodicalIF":4.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1016/j.mineng.2024.109154
Recep Kurtulus , Mahtab Akbarzadeh Khoei , Marco Cantaluppi , Juho Yliniemi
This study investigated electric arc furnace (EAF) slag dissolution in varying NaOH solutions (10 M, 0.1 M, and 0.01 M) and assessed the impact of ultrasonication on enhancing element release. After conducting dissolution tests based on 1/100 g/mL as the solid-to-liquid ratio, ICP-OES analysis was used in determining the dissolved elemental concentrations, while XRD, FTIR, BET, and XPS measurements facilitated understanding of the alterations in the structure and surface. According to the findings, Al, Si, Ca, and Fe elements dissolved in different concentrations, depending on the alkalinity level and technique applied. Higher alkalinity led to more Al and Si species dissolving, reaching up to 12 % dissolution. In contrast, moderate and slight alkalinity reduced the extent of dissolution (< 5 %) for Al and Si or even caused the disappearance of some species. Additionally, the results showed that ultrasonication provided more element releases, with up to 50 % enhancement, compared with stirring. XRD patterns revealed that the EAF slag had an intricate crystal structure including more than 15 phases. Use of 10 M NaOH solution resulted in a considerable breakdown of the EAF slag structure and the formation of new phases, whereas the change in structure was less prominent in 0.1 M and 0.01 M NaOH conditions. In another aspect, BET analysis showed that both alkalinity and ultrasonication increased the particle surface area. In conclusion, this study revealed that EAF slag released different elements with various concentrations and NaOH molarities, and ultrasonication was able to enhance the dissolution process to a certain degree.
本研究考察了电弧炉炉渣在不同NaOH溶液（10 M、0.1 M和0.01 M）中的溶解情况，并评估了超声波对促进元素释放的影响。以1/100 g/mL为固液比进行溶解测试后，采用ICP-OES分析测定溶解元素浓度，XRD、FTIR、BET和XPS测量有助于了解结构和表面的变化。根据研究结果，铝、硅、钙和铁元素的溶解浓度不同，取决于碱度水平和应用的技术。碱度越高，Al和Si的溶解度越高，溶解度可达12%。相反，中度和轻度碱度降低了溶解程度(<；5%)，甚至导致某些物种的消失。此外，结果表明，与搅拌相比，超声能提供更多的元素释放，释放强度可提高50%。XRD分析表明，电炉渣具有复杂的晶体结构，包括15个以上的相。使用10 M NaOH溶液时，电炉渣的结构发生了较大的破坏，形成了新的相，而在0.1 M和0.01 M NaOH条件下，结构变化不太明显。另一方面，BET分析表明碱度和超声处理均增加了颗粒表面积。综上所述，电炉渣释放出不同浓度、不同NaOH摩尔浓度的不同元素，超声处理能在一定程度上促进其溶解过程。
{"title":"Effects of combined alkalinity and ultrasonication on element release and structural alteration in EAF slag","authors":"Recep Kurtulus , Mahtab Akbarzadeh Khoei , Marco Cantaluppi , Juho Yliniemi","doi":"10.1016/j.mineng.2024.109154","DOIUrl":"10.1016/j.mineng.2024.109154","url":null,"abstract":"<div><div>This study investigated electric arc furnace (EAF) slag dissolution in varying NaOH solutions (10 M, 0.1 M, and 0.01 M) and assessed the impact of ultrasonication on enhancing element release. After conducting dissolution tests based on 1/100 g/mL as the solid-to-liquid ratio, ICP-OES analysis was used in determining the dissolved elemental concentrations, while XRD, FTIR, BET, and XPS measurements facilitated understanding of the alterations in the structure and surface. According to the findings, Al, Si, Ca, and Fe elements dissolved in different concentrations, depending on the alkalinity level and technique applied. Higher alkalinity led to more Al and Si species dissolving, reaching up to 12 % dissolution. In contrast, moderate and slight alkalinity reduced the extent of dissolution (< 5 %) for Al and Si or even caused the disappearance of some species. Additionally, the results showed that ultrasonication provided more element releases, with up to 50 % enhancement, compared with stirring. XRD patterns revealed that the EAF slag had an intricate crystal structure including more than 15 phases. Use of 10 M NaOH solution resulted in a considerable breakdown of the EAF slag structure and the formation of new phases, whereas the change in structure was less prominent in 0.1 M and 0.01 M NaOH conditions. In another aspect, BET analysis showed that both alkalinity and ultrasonication increased the particle surface area. In conclusion, this study revealed that EAF slag released different elements with various concentrations and NaOH molarities, and ultrasonication was able to enhance the dissolution process to a certain degree.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109154"},"PeriodicalIF":4.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1016/j.mineng.2024.109150
Daniel Uliana, Carina Ulsen
X-ray microtomography image analysis has demonstrated a great potential in in three-dimensional and non-destructive mineral samples characterization. Therefore, there is a drive from the international scientific community to develop new methodologies for three-dimensional image analysis, with the commitment to seek increasingly accurate results and better predictability in mineral processing. The main argument for this research approach is the mitigation of stereological bias, which is inherent in the analysis of two-dimensional (2D) images from optical and scanning electron microscopy techniques, despite being very robust, reliable and widely used techniques in mineral research for some decades. However, in addition to stereological bias, other sources of error should be considered, from sample preparation to the inherent limitations of the different analytical techniques. Thus, this work aims to contribute to the critical analysis of 2D and 3D mineralogical results and their impact on mineral liberation spectra of low-grade Brazilian iron ores with different mineralogical assemblages and textural relationships. Considering the four iron ore samples studied, no significant differences were observed in the overall 2D and 3D iron oxides liberation for sample IO-1 (not liberated) and sample IO-3 (with a high liberation degree). For sample IO-2 (with significantly higher liberation below 0.053 mm), the 2D results overestimate the overall liberation by 9 % when compared to 3D data. In sample IO-4, although the 2D liberation results range from 84 to 97 % in the range −0.15 + 0.020 mm, the 3D liberation values reach a maximum of 75–79 % in fractions below 0.053 mm, indicating a high stereological bias in all fractions, with an overestimation of 22 % of the overall liberation of the 2D results.
{"title":"Mineral liberation by 3D X-ray microtomography and SEM-based image analysis in low-grade iron ores with different mineralogy and texture","authors":"Daniel Uliana, Carina Ulsen","doi":"10.1016/j.mineng.2024.109150","DOIUrl":"10.1016/j.mineng.2024.109150","url":null,"abstract":"<div><div>X-ray microtomography image analysis has demonstrated a great potential in in three-dimensional and non-destructive mineral samples characterization. Therefore, there is a drive from the international scientific community to develop new methodologies for three-dimensional image analysis, with the commitment to seek increasingly accurate results and better predictability in mineral processing. The main argument for this research approach is the mitigation of stereological bias, which is inherent in the analysis of two-dimensional (2D) images from optical and scanning electron microscopy techniques, despite being very robust, reliable and widely used techniques in mineral research for some decades. However, in addition to stereological bias, other sources of error should be considered, from sample preparation to the inherent limitations of the different analytical techniques. Thus, this work aims to contribute to the critical analysis of 2D and 3D mineralogical results and their impact on mineral liberation spectra of low-grade Brazilian iron ores with different mineralogical assemblages and textural relationships. Considering the four iron ore samples studied, no significant differences were observed in the overall 2D and 3D iron oxides liberation for sample IO-1 (not liberated) and sample IO-3 (with a high liberation degree). For sample IO-2 (with significantly higher liberation below 0.053 mm), the 2D results overestimate the overall liberation by 9 % when compared to 3D data. In sample IO-4, although the 2D liberation results range from 84 to 97 % in the range −0.15 + 0.020 mm, the 3D liberation values reach a maximum of 75–79 % in fractions below 0.053 mm, indicating a high stereological bias in all fractions, with an overestimation of 22 % of the overall liberation of the 2D results.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109150"},"PeriodicalIF":4.9,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1016/j.mineng.2024.109156
Xiayu Zheng, Xingzhe Li, Li Du, Sheng Zhou, Yuhua Wang, Dongfang Lu
Ultrafine ilmenite minerals (−0.019 mm) in vanadic titanomagnetite ore deposit in Panxi area of China were generally separated by hydraulic classification and discharged into tailings as these fine minerals will severely deteriorate subsequent flotation process, resulting in a great waste of titanium resources. Methods combining high gradient magnetic separation (HGMS) followed by flotation were usually developed for recovering ultrafine ilmenite, which commonly had defects of long flowsheet, high reagent consumption and environmental pollution. In this study, high gradient magnetic separation coupling with magnetic fluid (HGMSCMF) was adopted to recover ultrafine ilmenite in Panxi area. Effect of MnCl2 concentration (magnetic susceptibility of fluid), applied induction and pulsating frequency on TiO2 grade and recovery of magnetic products in HGMSCMF were systematically investigated. Under optimal conditions of MnCl2 concentration 40 %, applied induction 0.8 T and pulsating frequency 300 r/min, magnetic concentrate assaying 46.09 % TiO2 could be obtained under TiO2 recovery of 43.58 % through three stages of HGMSCMF. Numerical simulation of capture of ilmenite and titanaugite particles by matrices were conducted, based on which variation of ratio of captured ilmenite particles with MnCl2 concentration and applied induction were studied. Theoretical results corresponded well with experimental results and indicated good adaptability of HGMSCMF to mineral particle size. A clean and short flowsheet incorporating recycling of magnetic fluids for continuous recovery of ultrafine ilmenite was developed. HGMSCMF presented great superiority and application prospect in cleaner and efficient utilization of ultrafine ilmenite, as well as other refractory weakly magnetic minerals.
{"title":"Clean and short flowsheet of recovering ultrafine ilmenite by high gradient magnetic separation coupling with magnetic fluid","authors":"Xiayu Zheng, Xingzhe Li, Li Du, Sheng Zhou, Yuhua Wang, Dongfang Lu","doi":"10.1016/j.mineng.2024.109156","DOIUrl":"10.1016/j.mineng.2024.109156","url":null,"abstract":"<div><div>Ultrafine ilmenite minerals (−0.019 mm) in vanadic titanomagnetite ore deposit in Panxi area of China were generally separated by hydraulic classification and discharged into tailings as these fine minerals will severely deteriorate subsequent flotation process, resulting in a great waste of titanium resources. Methods combining high gradient magnetic separation (HGMS) followed by flotation were usually developed for recovering ultrafine ilmenite, which commonly had defects of long flowsheet, high reagent consumption and environmental pollution. In this study, high gradient magnetic separation coupling with magnetic fluid (HGMSCMF) was adopted to recover ultrafine ilmenite in Panxi area. Effect of MnCl<sub>2</sub> concentration (magnetic susceptibility of fluid), applied induction and pulsating frequency on TiO<sub>2</sub> grade and recovery of magnetic products in HGMSCMF were systematically investigated. Under optimal conditions of MnCl<sub>2</sub> concentration 40 %, applied induction 0.8 T and pulsating frequency 300 r/min, magnetic concentrate assaying 46.09 % TiO<sub>2</sub> could be obtained under TiO<sub>2</sub> recovery of 43.58 % through three stages of HGMSCMF. Numerical simulation of capture of ilmenite and titanaugite particles by matrices were conducted, based on which variation of ratio of captured ilmenite particles with MnCl<sub>2</sub> concentration and applied induction were studied. Theoretical results corresponded well with experimental results and indicated good adaptability of HGMSCMF to mineral particle size. A clean and short flowsheet incorporating recycling of magnetic fluids for continuous recovery of ultrafine ilmenite was developed. HGMSCMF presented great superiority and application prospect in cleaner and efficient utilization of ultrafine ilmenite, as well as other refractory weakly magnetic minerals.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109156"},"PeriodicalIF":4.9,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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