Pub Date : 2024-09-03DOI: 10.1016/j.hydromet.2024.106385
Ultrasonic radiation is widely used in the enhancement of leaching process with outstanding advantages in leaching efficiency. In this study, a germanium concentrate was leached with NaClO and the influence of factors such as ultrasound power and oxidant addition on the leaching efficiency of germanium from the concentrate were investigated. The leaching efficiency of germanium reached 96.8% at the initial concentration of hydrochloric acid of 8 mol/L, the oxidant dosage of 1.5 g/L NaClO, the liquid-solid volume/mass ratio of 6 mL/g, the ultrasonic power density of 13.3 W/cm3, and the stirring speed of 300 rpm for 30 min at 60 °C. The leaching efficiency was 4.50% higher at a shorter leaching time and lower temperature, than that of the conventional process, which was mainly attributed to the ultrasonic multiple effects and NaClO. Meanwhile, NaClO can effectively oxidize As(III) into non-volatile As(V), remove arsenic in germanium, facilitate the subsequent distillation, improve the leaching efficiency, and be more environmentally friendly.
{"title":"Study on ultrasonic assisted intensive leaching of germanium from germanium concentrate using HCl/NaOCl","authors":"","doi":"10.1016/j.hydromet.2024.106385","DOIUrl":"10.1016/j.hydromet.2024.106385","url":null,"abstract":"<div><p>Ultrasonic radiation is widely used in the enhancement of leaching process with outstanding advantages in leaching efficiency. In this study, a germanium concentrate was leached with NaClO and the influence of factors such as ultrasound power and oxidant addition on the leaching efficiency of germanium from the concentrate were investigated. The leaching efficiency of germanium reached 96.8% at the initial concentration of hydrochloric acid of 8 mol/L, the oxidant dosage of 1.5 g/L NaClO, the liquid-solid volume/mass ratio of 6 mL/g, the ultrasonic power density of 13.3 W/cm<sup>3</sup>, and the stirring speed of 300 rpm for 30 min at 60 °C. The leaching efficiency was 4.50% higher at a shorter leaching time and lower temperature, than that of the conventional process, which was mainly attributed to the ultrasonic multiple effects and NaClO. Meanwhile, NaClO can effectively oxidize As(III) into non-volatile As(V), remove arsenic in germanium, facilitate the subsequent distillation, improve the leaching efficiency, and be more environmentally friendly.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1016/j.hydromet.2024.106395
<div><p>This study investigated the effects of mean particle size fraction, bottom particle size, particle porosity and wettability on solution scale preferential flow behaviour via step input tracer tests in drip irrigated, narrowly and mixed-sized beds under steady state fluid flux. Nine solute transport models were used to quantify this behaviour reflected in the residence time distribution (RTD) profiles. Four were empirical models: three compartmental model configurations (CM-1, CM-2, CM-3) and tanks-in-series (TIS) model. The remainder five models were semi-empirical: advection dispersion (AD), piston exchange (PE), piston exchange - diffusion variant (PE-D), piston dispersion and exchange (PDE) and piston dispersion and exchange - diffusion variant (PDE<img>D). The model fit results showed that the mono-porosity TIS, AD and CM-2 models were the worst performers, while the dual porosity PDE and novel PDE-D models achieved the lowest average error values across the various systems. Higher levels of particle wettability coupled with capillary effects produced peculiar RTD curves that were relatively more difficult for the mono-porosity models to simulate. The model parameters investigated included the longitudinal dispersion coefficient (<span><math><msub><mi>D</mi><mi>ds</mi></msub></math></span>), dead to total volume fraction (<span><math><msub><mi>V</mi><mi>D</mi></msub><mo>/</mo><msub><mi>V</mi><mi>T</mi></msub></math></span>), dynamic to total saturation fraction (<span><math><msub><mi>β</mi><mi>d</mi></msub><mo>/</mo><msub><mi>β</mi><mi>T</mi></msub></math></span>), overall mass transfer coefficient (<span><math><msub><mi>K</mi><mi>m</mi></msub><mi>a</mi></math></span>) and maximum diffusional pore length (<span><math><mi>X</mi></math></span>). The results showed that an increase in the average particle size within the beds led to higher <span><math><msub><mi>V</mi><mi>D</mi></msub><mo>/</mo><msub><mi>V</mi><mi>T</mi></msub></math></span>, <span><math><msub><mi>D</mi><mi>ds</mi></msub></math></span> and <span><math><mi>X</mi></math></span> values, but lower <span><math><msub><mi>β</mi><mi>d</mi></msub><mo>/</mo><msub><mi>β</mi><mi>T</mi></msub></math></span> and <span><math><msub><mi>K</mi><mi>m</mi></msub><mi>a</mi></math></span> values. These indicate an overall increase in solution scale preferential flow behaviour. Decreased capillary suction and connectivity between particle pores and inter-particle voids were deemed responsible for the results. Higher levels of particle porosity acted as a buffer against these effects. Overall, the results highlight the benefit of the addition of fines (0.1–1 mm particles) during the agglomeration process in heaps to help reduce solution scale preferential flow behaviour and increase liquid hold-up. This is more necessary when the ore has low to moderate levels of porosity (surface area: <span><math><mo><</mo></math></span>2 m<sup>2</sup>/g) and will also increase the modelling options availab
{"title":"Comparison of non-reactive solute transport models for the evaluation of fluid flow in packed beds with implications for heap leaching practice","authors":"","doi":"10.1016/j.hydromet.2024.106395","DOIUrl":"10.1016/j.hydromet.2024.106395","url":null,"abstract":"<div><p>This study investigated the effects of mean particle size fraction, bottom particle size, particle porosity and wettability on solution scale preferential flow behaviour via step input tracer tests in drip irrigated, narrowly and mixed-sized beds under steady state fluid flux. Nine solute transport models were used to quantify this behaviour reflected in the residence time distribution (RTD) profiles. Four were empirical models: three compartmental model configurations (CM-1, CM-2, CM-3) and tanks-in-series (TIS) model. The remainder five models were semi-empirical: advection dispersion (AD), piston exchange (PE), piston exchange - diffusion variant (PE-D), piston dispersion and exchange (PDE) and piston dispersion and exchange - diffusion variant (PDE<img>D). The model fit results showed that the mono-porosity TIS, AD and CM-2 models were the worst performers, while the dual porosity PDE and novel PDE-D models achieved the lowest average error values across the various systems. Higher levels of particle wettability coupled with capillary effects produced peculiar RTD curves that were relatively more difficult for the mono-porosity models to simulate. The model parameters investigated included the longitudinal dispersion coefficient (<span><math><msub><mi>D</mi><mi>ds</mi></msub></math></span>), dead to total volume fraction (<span><math><msub><mi>V</mi><mi>D</mi></msub><mo>/</mo><msub><mi>V</mi><mi>T</mi></msub></math></span>), dynamic to total saturation fraction (<span><math><msub><mi>β</mi><mi>d</mi></msub><mo>/</mo><msub><mi>β</mi><mi>T</mi></msub></math></span>), overall mass transfer coefficient (<span><math><msub><mi>K</mi><mi>m</mi></msub><mi>a</mi></math></span>) and maximum diffusional pore length (<span><math><mi>X</mi></math></span>). The results showed that an increase in the average particle size within the beds led to higher <span><math><msub><mi>V</mi><mi>D</mi></msub><mo>/</mo><msub><mi>V</mi><mi>T</mi></msub></math></span>, <span><math><msub><mi>D</mi><mi>ds</mi></msub></math></span> and <span><math><mi>X</mi></math></span> values, but lower <span><math><msub><mi>β</mi><mi>d</mi></msub><mo>/</mo><msub><mi>β</mi><mi>T</mi></msub></math></span> and <span><math><msub><mi>K</mi><mi>m</mi></msub><mi>a</mi></math></span> values. These indicate an overall increase in solution scale preferential flow behaviour. Decreased capillary suction and connectivity between particle pores and inter-particle voids were deemed responsible for the results. Higher levels of particle porosity acted as a buffer against these effects. Overall, the results highlight the benefit of the addition of fines (0.1–1 mm particles) during the agglomeration process in heaps to help reduce solution scale preferential flow behaviour and increase liquid hold-up. This is more necessary when the ore has low to moderate levels of porosity (surface area: <span><math><mo><</mo></math></span>2 m<sup>2</sup>/g) and will also increase the modelling options availab","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23DOI: 10.1016/j.hydromet.2024.106387
In the present study, the sorption of perrhenate ions from sulfuric acid liquors was studied using three types of polymer ion exchange resins. An anion exchange resin type 1 (a copolymer of 2-methyl-5-vinylpyridine with divinylbenzene (VP-DVB)) as well as two polyfunctional resins containing anion and cation exchange functional groups, namely, type 2 (a carboxylated VP-DVB with pyridine-2-carboxylic acid (picolinic acid) functional group) and type 3 (an aminophosphorylated VP-DVB with pyridine-2-[(methylamino)methyl]phosphonic acid functional group), were studied. The resins before and after rhenium sorption were characterized by FT-IR spectroscopy and XPS spectroscopy. The incorporation of additional acidic functional groups into the polymer matrix of the VP-DVB resins led to a slight decrease in the rhenium anion exchange capacity. At the same time, polyfunctional resins make it possible to strip rhenium with hydrochloric acid. A completely new process for the preconcentration of rhenium as a halide compound, which will contribute to the low-cost production of metallic rhenium, can be implemented using these new polyfunctional resins. Column sorption experiments using real uranium leach liquors demonstrated an exchange capacity of 33.2 mg of Re per gram of resin and a concentration factor in the eluate of ∼2500. The possibility of anion exchange recovery of rhenium from uranium leach liquors by Type 3 resin followed by direct precipitation of potassium hexachlororhenate from hydrochloric acid desorption liquor was demonstrated. The present study provided a new resin for rhenium recovery with excellent adsorption and elution characteristics, which is a promising candidate for practical applications.
{"title":"Anion exchange recovery of rhenium from industrial liquors followed by direct synthesis of a rhenium halide salt","authors":"","doi":"10.1016/j.hydromet.2024.106387","DOIUrl":"10.1016/j.hydromet.2024.106387","url":null,"abstract":"<div><p>In the present study, the sorption of perrhenate ions from sulfuric acid liquors was studied using three types of polymer ion exchange resins. An anion exchange resin type 1 (a copolymer of 2-methyl-5-vinylpyridine with divinylbenzene (VP-DVB)) as well as two polyfunctional resins containing anion and cation exchange functional groups, namely, type 2 (a carboxylated VP-DVB with pyridine-2-carboxylic acid (picolinic acid) functional group) and type 3 (an aminophosphorylated VP-DVB with pyridine-2-[(methylamino)methyl]phosphonic acid functional group), were studied. The resins before and after rhenium sorption were characterized by FT-IR spectroscopy and XPS spectroscopy. The incorporation of additional acidic functional groups into the polymer matrix of the VP-DVB resins led to a slight decrease in the rhenium anion exchange capacity. At the same time, polyfunctional resins make it possible to strip rhenium with hydrochloric acid. A completely new process for the preconcentration of rhenium as a halide compound, which will contribute to the low-cost production of metallic rhenium, can be implemented using these new polyfunctional resins. Column sorption experiments using real uranium leach liquors demonstrated an exchange capacity of 33.2 mg of Re per gram of resin and a concentration factor in the eluate of ∼2500. The possibility of anion exchange recovery of rhenium from uranium leach liquors by Type 3 resin followed by direct precipitation of potassium hexachlororhenate from hydrochloric acid desorption liquor was demonstrated. The present study provided a new resin for rhenium recovery with excellent adsorption and elution characteristics, which is a promising candidate for practical applications.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1016/j.hydromet.2024.106383
In this study, the mineralogy of a novel resource of deep-sea sediments containing rare earth elements (REEs) was investigated, along with the leaching of REEs using hydrochloric acid. The results revealed that, apart from 62.0% of the Ce found in the Mn oxides, the other REEs in the deep-sea sediments mostly existed in hydroxyapatite mineral which can be easily decomposed via a hydrochloric acid leaching. An optimized REEs leaching percentage of 89.5% was achieved using 2.0 mol/L hydrochloric acid as the leaching agent, with a liquid-solid ratio of 4:1, at 60 °C for 30 min. However, Mn oxides remained stable during the leaching process, resulting in a low Ce leaching percentage of 30.7%. Under the optimized conditions, Mn oxides could be decomposed by adding 30% H2O2 as a reducing agent, leading to improved leaching percentages of Ce and REEs to 86.6% and 93.2%, respectively. The high leaching efficiency of REEs may further increase the utilization potential of this novel resource.
本研究调查了含有稀土元素(REEs)的深海沉积物新资源的矿物学,以及使用盐酸浸出稀土元素的情况。结果表明,除了 62.0% 的铈存在于锰氧化物中外,深海沉积物中的其他稀土元素大多存在于羟基磷灰石矿物中,而羟基磷灰石矿物很容易通过盐酸浸出法分解。使用 2.0 mol/L 盐酸作为浸出剂,液固比为 4:1,在 60 °C 下浸出 30 分钟,REEs 的最佳浸出率为 89.5%。然而,锰氧化物在浸出过程中保持稳定,导致 Ce 浸出率较低,仅为 30.7%。在优化条件下,加入 30% 的 H2O2 作为还原剂可分解锰氧化物,从而使 Ce 和 REEs 的浸出率分别提高到 86.6% 和 93.2%。REEs 的高浸出效率可进一步提高这种新型资源的利用潜力。
{"title":"Hydrochloric acid leaching of rare earth elements from a novel source of deep-sea sediments and advantage of reduction with H2O2","authors":"","doi":"10.1016/j.hydromet.2024.106383","DOIUrl":"10.1016/j.hydromet.2024.106383","url":null,"abstract":"<div><p>In this study, the mineralogy of a novel resource of deep-sea sediments containing rare earth elements (REEs) was investigated, along with the leaching of REEs using hydrochloric acid. The results revealed that, apart from 62.0% of the Ce found in the Mn oxides, the other REEs in the deep-sea sediments mostly existed in hydroxyapatite mineral which can be easily decomposed via a hydrochloric acid leaching. An optimized REEs leaching percentage of 89.5% was achieved using 2.0 mol/L hydrochloric acid as the leaching agent, with a liquid-solid ratio of 4:1, at 60 °C for 30 min. However, Mn oxides remained stable during the leaching process, resulting in a low Ce leaching percentage of 30.7%. Under the optimized conditions, Mn oxides could be decomposed by adding 30% H<sub>2</sub>O<sub>2</sub> as a reducing agent, leading to improved leaching percentages of Ce and REEs to 86.6% and 93.2%, respectively. The high leaching efficiency of REEs may further increase the utilization potential of this novel resource.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1016/j.hydromet.2024.106386
The key to achieving sustainable metal extraction development is to avoid the generation of high-salt wastewater from the source. Here, a new system for the extraction and separation of lanthanide elements Eu(III), Gd(III) and Tb(III) from the acetic acid solution using HEHEHP (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) was studied. The corresponding parameters including contact time, HEHEHP concentration, concentrations of rare earth metal ions and acetic acid in the initial solution, aqueous/organic phase volume ratio (R(A/O)), and temperature were considered to optimize the conditions for the separation of different rare earth elements. The results showed that the separation coefficients of Tb(III)/Gd(III) and Gd(III)/Eu(III) in the acetic acid system were approximately 6.2 and 1.7, with HEHEHP of 0.15 mol/L and R(A/O) of 2:1, and the extraction efficiency of RE(III) reached approximately 73.1%, which was higher than that in the hydrochloric acid and sulfuric acid systems. The mechanism associated with the extraction reaction was evaluated and discussed by the maximum loading capacity method, chromatographic analysis, and FT-IR spectrometric analysis. The mechanism followed a cation exchange reaction and acetic acid did not participate in the extraction process. The feasibility of the separation of Tb(III) from Eu(III) and Gd(III)was also given in terms of the separation coefficients between different elements at different extraction conditions. Since saponification is not necessary in the acetic acid extraction system, it can considerably reduce wastewater discharge to the ecological environment from the source.
{"title":"Environmentally friendly non-saponification solvent extraction and separation process for RE(III) (RE = Eu, Gd and Tb) in acetic acid solution using HEHEHP/n-heptane","authors":"","doi":"10.1016/j.hydromet.2024.106386","DOIUrl":"10.1016/j.hydromet.2024.106386","url":null,"abstract":"<div><p>The key to achieving sustainable metal extraction development is to avoid the generation of high-salt wastewater from the source. Here, a new system for the extraction and separation of lanthanide elements Eu(III), Gd(III) and Tb(III) from the acetic acid solution using HEHEHP (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) was studied. The corresponding parameters including contact time, HEHEHP concentration, concentrations of rare earth metal ions and acetic acid in the initial solution, aqueous/organic phase volume ratio (R<sub>(A/O)</sub>), and temperature were considered to optimize the conditions for the separation of different rare earth elements. The results showed that the separation coefficients of Tb(III)/Gd(III) and Gd(III)/Eu(III) in the acetic acid system were approximately 6.2 and 1.7, with HEHEHP of 0.15 mol/L and R<sub>(A/O)</sub> of 2:1, and the extraction efficiency of RE(III) reached approximately 73.1%, which was higher than that in the hydrochloric acid and sulfuric acid systems. The mechanism associated with the extraction reaction was evaluated and discussed by the maximum loading capacity method, chromatographic analysis, and FT-IR spectrometric analysis. The mechanism followed a cation exchange reaction and acetic acid did not participate in the extraction process. The feasibility of the separation of Tb(III) from Eu(III) and Gd(<em>III</em>)was also given in terms of the separation coefficients between different elements at different extraction conditions. Since saponification is not necessary in the acetic acid extraction system, it can considerably reduce wastewater discharge to the ecological environment from the source.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-18DOI: 10.1016/j.hydromet.2024.106384
Trichloroisocyanuric acid (TCCA), which is used for gold leaching, is an alternative to cyanidation due to its lower toxicity and higher efficiency. This study investigated the gold recovery procedures from highly effective chloride leaching solution using the D301 resin. This approach prevented the inhibition of gold adsorption when using activated carbon. Herein, the optimal conditions for gold adsorption were discussed, including establishing adsorption kinetics and isotherms, and calculating adsorption activation energy. Additionally, SEM (Scanning Electron Microscope), FTIR (Fourier Transform Infrared Spectroscopy), and XPS (X-ray Photoelectron Spectroscopy) techniques were used to reveal the mechanism of gold adsorption using D301 resin. Under optimal conditions (pH 4.0, temperature 25 °C, time 120 min), an average adsorption percentage of 99.2% was achieved. Analysis of the adsorption data confirmed that gold adsorption followed the pseudo-second-order kinetic model and Freundlich adsorption isotherm. The calculated activation energy was 9.69 kJ mol−1, indicating a predominance of physical adsorption involving ion exchange reactions with protonated tertiary amine groups in the D301 resin beads. Furthermore, among various eluents tested in desorption experiments, a solution containing a mixture of thiourea and hydrochloric acid with 0.4 mol L−1 and 0.8 mol L−1, respectively, demonstrated superior efficiency, achieving a successful desorption percentage reaching 95.7 ± 0.3% within 80 min. After three cycles of resin regeneration, the regeneration efficiency reached 91.2% while maintaining an average adsorption percentage of 95.3%.
{"title":"Gold recovery from chloride leach solution of TCCA using D301 anion exchange resin and elution with thiourea","authors":"","doi":"10.1016/j.hydromet.2024.106384","DOIUrl":"10.1016/j.hydromet.2024.106384","url":null,"abstract":"<div><p>Trichloroisocyanuric acid (TCCA), which is used for gold leaching, is an alternative to cyanidation due to its lower toxicity and higher efficiency. This study investigated the gold recovery procedures from highly effective chloride leaching solution using the D301 resin. This approach prevented the inhibition of gold adsorption when using activated carbon. Herein, the optimal conditions for gold adsorption were discussed, including establishing adsorption kinetics and isotherms, and calculating adsorption activation energy. Additionally, SEM (Scanning Electron Microscope), FTIR (Fourier Transform Infrared Spectroscopy), and XPS (X-ray Photoelectron Spectroscopy) techniques were used to reveal the mechanism of gold adsorption using D301 resin. Under optimal conditions (pH 4.0, temperature 25 °C, time 120 min), an average adsorption percentage of 99.2% was achieved. Analysis of the adsorption data confirmed that gold adsorption followed the pseudo-second-order kinetic model and Freundlich adsorption isotherm. The calculated activation energy was 9.69 kJ mol<sup>−1</sup>, indicating a predominance of physical adsorption involving ion exchange reactions with protonated tertiary amine groups in the D301 resin beads. Furthermore, among various eluents tested in desorption experiments, a solution containing a mixture of thiourea and hydrochloric acid with 0.4 mol L<sup>−1</sup> and 0.8 mol L<sup>−1</sup>, respectively, demonstrated superior efficiency, achieving a successful desorption percentage reaching 95.7 ± 0.3% within 80 min. After three cycles of resin regeneration, the regeneration efficiency reached 91.2% while maintaining an average adsorption percentage of 95.3%.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1016/j.hydromet.2024.106381
Spent hydrodesulfurization (HDS) catalysts containing large amounts of valuable metals, such as Mo and V, are hazardous solid wastes but also valuable secondary resources. However, the current recovery process suffers from the difficulty of balancing the leaching efficiency of Mo and V and their selectivity over Al. This work focused on the effect of phase transformation during roasting operation on the leaching behavior Mo, V, and Al and adopted an oxidation roasting followed by mixed alkali of Na2CO3 and NaOH leaching process to recover Mo and V from spent HDS catalysts. The results indicated that the phase transformation of Mo, V, and Al species during oxidation roasting process played a crucial role in achieving efficient leaching of Mo and V, as well as reducing leaching efficiency of Al. This transformation involved the change in Mo and V species changed from low valent compounds to high valent oxides, and Al2O3 from γ-phase to θ- and α-phases. In addition, efficient and selective leaching of 99.3% Mo and 97.8% V was realized, with only 0.03% Al being dissolved, by roasting the spent catalysts at 700 °C for 2 h and then leaching with a mixed solution of 1.2 mol/L Na2CO3 and 1.6 mol/L NaOH. The efficient and selective leaching of Mo and V can significantly reduce the burden of subsequent separation and purification, which provided an important prerequisite for the development of a new process for the recovery of Mo and V from HDS spent catalysts in alkaline systems.
含大量有价金属(如钼和钒)的加氢脱硫(HDS)催化剂废料是危险的固体废物,但也是宝贵的二次资源。然而,目前的回收工艺难以平衡钼和钒的浸出效率及其对铝的选择性。本研究重点研究了焙烧操作过程中的相变对 Mo、V 和 Al 的浸出行为的影响,并采用氧化焙烧后再用 Na2CO3 和 NaOH 混合碱浸出的工艺来回收 HDS 废催化剂中的 Mo 和 V。结果表明,氧化焙烧过程中 Mo、V 和 Al 物种的相变对实现 Mo 和 V 的高效浸出以及降低 Al 的浸出效率起着至关重要的作用。这种转变涉及 Mo 和 V 物种从低价化合物转变为高价氧化物,Al2O3 从 γ 相转变为 θ 和 α 相。此外,通过将废催化剂在 700 °C 下焙烧 2 小时,然后用 1.2 mol/L Na2CO3 和 1.6 mol/L NaOH 混合溶液浸出,实现了 99.3% Mo 和 97.8% V 的高效和选择性浸出,仅溶解了 0.03% Al。钼和钒的高效和选择性浸出可大大减轻后续分离和提纯的负担,这为开发在碱性体系中从加氢脱硫废催化剂中回收钼和钒的新工艺提供了重要的先决条件。
{"title":"Efficient and selective recovery of Mo and V from spent hydrodesulfurization catalysts via oxidation roasting followed by Na2CO3 and NaOH leaching","authors":"","doi":"10.1016/j.hydromet.2024.106381","DOIUrl":"10.1016/j.hydromet.2024.106381","url":null,"abstract":"<div><p>Spent hydrodesulfurization (HDS) catalysts containing large amounts of valuable metals, such as Mo and V, are hazardous solid wastes but also valuable secondary resources. However, the current recovery process suffers from the difficulty of balancing the leaching efficiency of Mo and V and their selectivity over Al. This work focused on the effect of phase transformation during roasting operation on the leaching behavior Mo, V, and Al and adopted an oxidation roasting followed by mixed alkali of Na<sub>2</sub>CO<sub>3</sub> and NaOH leaching process to recover Mo and V from spent HDS catalysts. The results indicated that the phase transformation of Mo, V, and Al species during oxidation roasting process played a crucial role in achieving efficient leaching of Mo and V, as well as reducing leaching efficiency of Al. This transformation involved the change in Mo and V species changed from low valent compounds to high valent oxides, and Al<sub>2</sub>O<sub>3</sub> from γ-phase to θ- and α-phases. In addition, efficient and selective leaching of 99.3% Mo and 97.8% V was realized, with only 0.03% Al being dissolved, by roasting the spent catalysts at 700 °C for 2 h and then leaching with a mixed solution of 1.2 mol/L Na<sub>2</sub>CO<sub>3</sub> and 1.6 mol/L NaOH. The efficient and selective leaching of Mo and V can significantly reduce the burden of subsequent separation and purification, which provided an important prerequisite for the development of a new process for the recovery of Mo and V from HDS spent catalysts in alkaline systems.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.hydromet.2024.106382
The regeneration of failed hydroxyoxime extractants in the copper hydrometallurgy industry is crucial. However, the existing regeneration system has limitations in terms of operability, yield, and environmental friendliness, which restricts its industrial application. This paper presents a clean one-pot ammoximation regeneration system for the in-situ preparation of hydroxylamine for the oximation of aldehydes, catalyzed by TS-1 with NH3 and H2O2. It was tailored based on the characteristics of the degraded organic phase produced by long-term operation at the copper solvent extraction site. The developed system demonstrates an excellent regeneration conversion efficiency (>90%) for the degraded copper-extracted organic phase. Following regeneration, the copper extraction efficiency of the organic phase reaches the same level as the fresh organic phase and maintains good copper extraction stability even after multiple extraction cycles. Moreover, the phase separation performance was improved through optimization. This regeneration system meets the demand for environmentally friendly and resourceful utilization of degraded waste organic phases in copper extraction systems.
在铜湿法冶金工业中,失效羟肟类萃取剂的再生至关重要。然而,现有的再生系统在可操作性、产量和环保性等方面存在局限性,限制了其工业应用。本文介绍了一种清洁的单锅氨肟化再生系统,用于在 TS-1 与 NH 和 HO 催化下原位制备羟胺,用于醛的肟化反应。该系统是根据铜溶剂萃取场所长期运行产生的降解有机相的特性定制的。所开发的系统对降解的铜萃取有机相具有出色的再生转化效率(大于 90%)。再生后,有机相的铜萃取效率达到了与新鲜有机相相同的水平,即使经过多次萃取循环也能保持良好的铜萃取稳定性。此外,通过优化还提高了相分离性能。该再生系统满足了铜萃取系统中降解废有机相的环保和资源化利用需求。
{"title":"Efficient ammoximation and regeneration of degraded hydroxyoxime CP150 over TS-1 molecular sieve/H2O2 system and reuse for solvent extraction of Cu(II)","authors":"","doi":"10.1016/j.hydromet.2024.106382","DOIUrl":"10.1016/j.hydromet.2024.106382","url":null,"abstract":"<div><p>The regeneration of failed hydroxyoxime extractants in the copper hydrometallurgy industry is crucial. However, the existing regeneration system has limitations in terms of operability, yield, and environmental friendliness, which restricts its industrial application. This paper presents a clean one-pot ammoximation regeneration system for the in-situ preparation of hydroxylamine for the oximation of aldehydes, catalyzed by TS-1 with NH<sub>3</sub> and H<sub>2</sub>O<sub>2</sub>. It was tailored based on the characteristics of the degraded organic phase produced by long-term operation at the copper solvent extraction site. The developed system demonstrates an excellent regeneration conversion efficiency (>90%) for the degraded copper-extracted organic phase. Following regeneration, the copper extraction efficiency of the organic phase reaches the same level as the fresh organic phase and maintains good copper extraction stability even after multiple extraction cycles. Moreover, the phase separation performance was improved through optimization. This regeneration system meets the demand for environmentally friendly and resourceful utilization of degraded waste organic phases in copper extraction systems.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141986699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-31DOI: 10.1016/j.hydromet.2024.106380
The low bio-production of Fe3+ as a leaching agent is one of the main limitations to implementing industrial bio-processes at feasibility conditions. The main limitation of the bio-oxidation process of Fe2+ is the low oxygen transfer to the aqueous phase because of the low oxygen solubility. This study assesses the effectiveness of the venturi jet as an innovative and intensive aeration device for overcoming the oxygen limitation in a continuous ferrous oxidation process in a fixed-bed reactor with immobilized acidithiobacillus ferrooxidans, in contrast to the conventional diffuser aeration device. Firstly, the influence of the airflow and the influence of the medium concentration were determined for the following parameters for both aeration devices; Volumetric mass transfer coefficient (kLa), Standard Oxygen Transfer Rate (SOTR), Standard Aeration Efficiency (SAE), and Standard Oxygen Transfer Efficiency (SOTE). Then, both aeration devices were compared in a continuous bio-oxidation process in an up-flow packed bio-reactor (UFPB). The system performance was assessed by monitoring temperature, pH, oxidation-reduction potential, and dissolved oxygen concentration for 69 days. Findings displayed that when aerating with the diffuser, the ferrous oxidation rate was restricted by the low dissolved oxygen availability, being about 1 ppm (1 mg L−1). Under these oxygen-limiting conditions, the maximum ferrous (Fe2+) oxidation rate was 9.09 g L−1 h−1. However, when aerating with the venturi jet, the dissolved oxygen concentration increased up to 2.70 mg L−1, achieving a maximum of 29.11 g L−1 h−1. So, this study has demonstrated that the change in the aeration device has resulted in an improvement in the process, achieving a 3.5-fold increase in the oxidation rate. Furthermore, the venturi jet offered additional advantages over the diffuser, such as requiring less power to deliver the same amount of air, being unaffected by jarosite precipitates, and not requiring a supply of compressed air.
{"title":"Improving the transfer of dissolved oxygen in a biological Fe2+ oxidation process using a venturi jet as an intensive aeration system","authors":"","doi":"10.1016/j.hydromet.2024.106380","DOIUrl":"10.1016/j.hydromet.2024.106380","url":null,"abstract":"<div><p>The low bio-production of Fe<sup>3+</sup> as a leaching agent is one of the main limitations to implementing industrial bio-processes at feasibility conditions. The main limitation of the bio-oxidation process of Fe<sup>2+</sup> is the low oxygen transfer to the aqueous phase because of the low oxygen solubility. This study assesses the effectiveness of the venturi jet as an innovative and intensive aeration device for overcoming the oxygen limitation in a continuous ferrous oxidation process in a fixed-bed reactor with immobilized <em>acidithiobacillus ferrooxidans</em>, in contrast to the conventional diffuser aeration device. Firstly, the influence of the airflow and the influence of the medium concentration were determined for the following parameters for both aeration devices; Volumetric mass transfer coefficient (k<sub>L</sub>a), Standard Oxygen <em>Transfer</em> Rate (SOTR), Standard Aeration Efficiency (SAE), and Standard Oxygen Transfer Efficiency (SOTE). Then, both aeration devices were compared in a continuous bio-oxidation process in an up-flow packed bio-reactor (UFPB). The system performance was assessed by monitoring temperature, pH, oxidation-reduction potential, and dissolved oxygen concentration for 69 days. Findings displayed that when aerating with the diffuser, the ferrous oxidation rate was restricted by the low dissolved oxygen availability, being about 1 ppm (1 mg L<sup>−1</sup>). Under these oxygen-limiting conditions, the maximum ferrous (Fe<sup>2+</sup>) oxidation rate was 9.09 g L<sup>−1</sup> h<sup>−1</sup>. However, when aerating with the venturi jet, the dissolved oxygen concentration increased up to 2.70 mg L<sup>−1</sup>, achieving a maximum of 29.11 g L<sup>−1</sup> h<sup>−1</sup>. So, this study has demonstrated that the change in the aeration device has resulted in an improvement in the process, achieving a 3.5-fold increase in the oxidation rate. Furthermore, the venturi jet offered additional advantages over the diffuser, such as requiring less power to deliver the same amount of air, being unaffected by jarosite precipitates, and not requiring a supply of compressed air.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1016/j.hydromet.2024.106379
The phosphoric acid produced by the nitric acid method cannot be used as an industrial-grade product as a result of the high calcium nitrate content. It can only be used for fertilizer production due to difficulty of complete removal of calcium nitrate. Herein, an efficient approach for the removal of calcium nitrate from the phosphoric acid produced by the nitric acid process was studied. The proposed process is based on solvent extraction with N, N, N′, N′-tetracyclohexyl-3-oxyglutaramide (TCHDGA). The effects of time, diluent, temperature, impurity ions, and the concentrations of extractant and nitric acid on the extraction of Ca2+ were considered. A series of characterization tests involving FT-IR spectroscopy, XPS analysis, slope analysis and X-ray single crystal diffracted analysis revealed that the stoichiometry of the complex is (Ca(NO3)2)(TCHDGA)3. The concentration of Ca2+ in phosphoric acid drops below 5 mg/L a three-stage cross-current extraction process. The stripping efficiency of calcium nitrate in the organic phase by water is above 99.9%. The extraction efficiency of Ca2+ by TCHDGA remained above 96.8% after ten extraction-stripping cycles, realizing the efficient removal of calcium nitrate in the phosphoric acid produced by nitric acid process without changing the traditional production conditions.
由于硝酸钙含量较高,硝酸法生产的磷酸不能用作工业级产品。由于难以完全去除硝酸钙,只能用于化肥生产。在此,研究了一种从硝酸法生产的磷酸中去除硝酸钙的有效方法。所提出的工艺基于 N,N,N′,N′-四环己基-3-氧戊二酰胺(TCHDGA)的溶剂萃取。考虑了时间、稀释剂、温度、杂质离子以及萃取剂和硝酸浓度对钙萃取的影响。通过一系列表征测试,包括傅立叶变换红外光谱、XPS 分析、斜率分析和 X 射线单晶衍射分析,发现复合物的化学计量为 (Ca(NO))(TCHDGA)。通过三级横流萃取工艺,磷酸中的钙浓度降至 5 mg/L 以下。水对有机相中硝酸钙的汽提效率高于 99.9%。经过十次萃取-剥离循环,TCHDGA 对 Ca 的萃取效率保持在 96.8%以上,在不改变传统生产条件的情况下,实现了对硝酸法生产的磷酸中硝酸钙的高效去除。
{"title":"Removal of calcium from phosphoric acid produced by the nitric acid process using solvent extraction with TCHDGA and stripping with water","authors":"","doi":"10.1016/j.hydromet.2024.106379","DOIUrl":"10.1016/j.hydromet.2024.106379","url":null,"abstract":"<div><p>The phosphoric acid produced by the nitric acid method cannot be used as an industrial-grade product as a result of the high calcium nitrate content. It can only be used for fertilizer production due to difficulty of complete removal of calcium nitrate. Herein, an efficient approach for the removal of calcium nitrate from the phosphoric acid produced by the nitric acid process was studied. The proposed process is based on solvent extraction with N, N, N′, N′-tetracyclohexyl-3-oxyglutaramide (TCHDGA). The effects of time, diluent, temperature, impurity ions, and the concentrations of extractant and nitric acid on the extraction of Ca<sup>2+</sup> were considered. A series of characterization tests involving FT-IR spectroscopy, XPS analysis, slope analysis and X-ray single crystal diffracted analysis revealed that the stoichiometry of the complex is (Ca(NO<sub>3</sub>)<sub>2</sub>)(TCHDGA)<sub>3</sub>. The concentration of Ca<sup>2+</sup> in phosphoric acid drops below 5 mg/L a three-stage cross-current extraction process. The stripping efficiency of calcium nitrate in the organic phase by water is above 99.9%. The extraction efficiency of Ca<sup>2+</sup> by TCHDGA remained above 96.8% after ten extraction-stripping cycles, realizing the efficient removal of calcium nitrate in the phosphoric acid produced by nitric acid process without changing the traditional production conditions.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}