Flotation of small particles is one of the global challenges facing the mineral raw materials processing industry. Large amounts of non-ferrous and rare metals are lost in the flotation tailings in the form of mineral particles below 15 µm in size as a result of the low effectiveness of their capture by coarse bubbles generated in conventional flotation machines. The method of combined microflotation, developed in recent years, uses conventional coarse bubbles (CB) and microbubbles (MB) produced in the stand-alone generator of air-in-water microdispersion, which serves as the flotation carriers. Depending on the MB dose, the effect of their application may be positive or negative. The theoretical analysis of various mechanisms of particle transfer onto the surface of coarse bubbles and further into the froth layer allowed to obtain the formula for the optimal MB dose f=dd/2dprp, where dd is MB size; dp and rp respectively are the size and the density of particles. Experiments performed on the copper ore flotation tailings at the Atalaya Mining (Spain) and Chaarat Kapan (Armenia) concentrators showed that, besides the optimal MB dose in the range of 1-3 ml/g, there is another optimal MB dose in the range of 10-20 ml/g, where the copper recovery increases by several percent compared to the reference test (f = 0). The deep minimum in copper recovery is observed in the area between the optimal MB doses, which is by several percent lower than the value in the reference test.
{"title":"The role of microbubble dose in combined microflotation of fine particles","authors":"Nickolay Rulyov","doi":"10.37190/ppmp/190630","DOIUrl":"https://doi.org/10.37190/ppmp/190630","url":null,"abstract":"Flotation of small particles is one of the global challenges facing the mineral raw materials processing industry. Large amounts of non-ferrous and rare metals are lost in the flotation tailings in the form of mineral particles below 15 µm in size as a result of the low effectiveness of their capture by coarse bubbles generated in conventional flotation machines. The method of combined microflotation, developed in recent years, uses conventional coarse bubbles (CB) and microbubbles (MB) produced in the stand-alone generator of air-in-water microdispersion, which serves as the flotation carriers. Depending on the MB dose, the effect of their application may be positive or negative. The theoretical analysis of various mechanisms of particle transfer onto the surface of coarse bubbles and further into the froth layer allowed to obtain the formula for the optimal MB dose f=dd/2dprp, where dd is MB size; dp and rp respectively are the size and the density of particles. Experiments performed on the copper ore flotation tailings at the Atalaya Mining (Spain) and Chaarat Kapan (Armenia) concentrators showed that, besides the optimal MB dose in the range of 1-3 ml/g, there is another optimal MB dose in the range of 10-20 ml/g, where the copper recovery increases by several percent compared to the reference test (f = 0). The deep minimum in copper recovery is observed in the area between the optimal MB doses, which is by several percent lower than the value in the reference test.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"26 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bangqi Wei, Jie Li, Zhao Cao, Saisai Ma, Yuhan Zhang
Herein, the flotation behavior of fluorite and calcite was examined before and after starch esterification through mineral flotation experiments. Moreover, the adsorption action mechanisms on minerals before and after starch esterification were investigated using methods such as solution surface tension measurement, infrared spectroscopy, and extended Derjaguin–Landau–Verwey–Overbeek theory. The results showed that after starch esterification (esterified starch), there was a greater difference in the mineral recovery rate compared to before starch esterification (ordinary starch), with a better inhibition effect on calcite. The interaction between mineral surfaces and ordinary starch was weaker than the interaction between minerals and esterified starch. In particular, after starch esterification, the surface tension increased, two minerals contact angle decreased, the surface potential became more negative, and the difference in the mineral recovery rate was greater than before starch esterification. After the interaction between minerals and esterified starch, calcite particles displayed good dispersibility, while the cohesion between calcite particles and sodium oleate particles decreased; notably, the effect on fluorite was opposite. Calcite and esterified starch exhibited chemical adsorption, impeding the adsorption of sodium oleate onto calcite and resulting in calcite inhibition. The interaction between fluorite surface and esterified starch involved electrostatic adsorption, with sodium oleate chemically adsorbed onto the fluorite surface. Chemical adsorption proved stronger than electrostatic adsorption, enabling sodium oleate to capture fluorite.
{"title":"The inhibition mechanism of esterified starch on flotation separation of fluorite and calcite","authors":"Bangqi Wei, Jie Li, Zhao Cao, Saisai Ma, Yuhan Zhang","doi":"10.37190/ppmp/190698","DOIUrl":"https://doi.org/10.37190/ppmp/190698","url":null,"abstract":"Herein, the flotation behavior of fluorite and calcite was examined before and after starch esterification through mineral flotation experiments. Moreover, the adsorption action mechanisms on minerals before and after starch esterification were investigated using methods such as solution surface tension measurement, infrared spectroscopy, and extended Derjaguin–Landau–Verwey–Overbeek theory. The results showed that after starch esterification (esterified starch), there was a greater difference in the mineral recovery rate compared to before starch esterification (ordinary starch), with a better inhibition effect on calcite. The interaction between mineral surfaces and ordinary starch was weaker than the interaction between minerals and esterified starch. In particular, after starch esterification, the surface tension increased, two minerals contact angle decreased, the surface potential became more negative, and the difference in the mineral recovery rate was greater than before starch esterification. After the interaction between minerals and esterified starch, calcite particles displayed good dispersibility, while the cohesion between calcite particles and sodium oleate particles decreased; notably, the effect on fluorite was opposite. Calcite and esterified starch exhibited chemical adsorption, impeding the adsorption of sodium oleate onto calcite and resulting in calcite inhibition. The interaction between fluorite surface and esterified starch involved electrostatic adsorption, with sodium oleate chemically adsorbed onto the fluorite surface. Chemical adsorption proved stronger than electrostatic adsorption, enabling sodium oleate to capture fluorite.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiantao Gu, Zhitao Yuan, Yusheng Du, Wei Ji Lu, Chuan Yang, Hongyang Lv
Oxidation roasting was proposed to treat the problem of the weak magnetic properties of ilmenite. The effects of roasting temperature, roasting time and cooling method on the results of ilmenite magnetic separation were studied. At the same time, the mechanism of the oxidation roasting process was analyzed by XRD, VSM, SEM-EDS. Determine ilmenite suitable oxidation roasting conditions for roasting temperature 750 °C, roasting time of 20 min, and cooling method of air cooling; at this time, the yield of 96.79% can be achieved in the magnetic field intensity of 238.74 kA/m. The XRD results showed that phase changes in the roasting process occur in the order of ilmenite to hematite and rutile to pseudobrookite. The results of VSM showed that the maximum specific magnetization coefficient of ilmenite increased from 3.25×10-5 m3/kg to 5.58×10-5 m3/kg after roasting, and the magnetic property was enhanced. The results of SEM-EDS showed that the phase transition of ilmenite during the roasting process occurs in a spatial order from the edge of the particles to the interior.
{"title":"Enhancement of ilmenite magnetic properties by oxidation roasting and magnetic separation","authors":"Jiantao Gu, Zhitao Yuan, Yusheng Du, Wei Ji Lu, Chuan Yang, Hongyang Lv","doi":"10.37190/ppmp/190706","DOIUrl":"https://doi.org/10.37190/ppmp/190706","url":null,"abstract":"Oxidation roasting was proposed to treat the problem of the weak magnetic properties of ilmenite. The effects of roasting temperature, roasting time and cooling method on the results of ilmenite magnetic separation were studied. At the same time, the mechanism of the oxidation roasting process was analyzed by XRD, VSM, SEM-EDS. Determine ilmenite suitable oxidation roasting conditions for roasting temperature 750 °C, roasting time of 20 min, and cooling method of air cooling; at this time, the yield of 96.79% can be achieved in the magnetic field intensity of 238.74 kA/m. The XRD results showed that phase changes in the roasting process occur in the order of ilmenite to hematite and rutile to pseudobrookite. The results of VSM showed that the maximum specific magnetization coefficient of ilmenite increased from 3.25×10-5 m3/kg to 5.58×10-5 m3/kg after roasting, and the magnetic property was enhanced. The results of SEM-EDS showed that the phase transition of ilmenite during the roasting process occurs in a spatial order from the edge of the particles to the interior.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"30 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huaiying Fang, Xiaosheng Ji, Jianhong Yang, Yuxuan Yang, Tianchen Ji, Chaoming Wei
The size of the discharge outlet of a cone crusher directly impacts the size of the aggregate produced. However, the discharge outlet is still adjusted manually, which has a significant error and affects production efficiency. For this reason, this study proposed an adaptive control method for cone crushers based on aggregate online detection. Firstly, the aggregate image was segmented using an instance segmentation model and the anchor and structure of the model were optimised. Then, this study proposed an evaluation method for quickly and accurately assessing the overall segmentation effect of network models. By comparing the results with those before optimisation, the accuracy of the optimised network model was improved from 0.923 to 0.940. Finally, an adaptive control experiment was conducted based on the online aggregate detection results. The experimental results showed that the discharge particle size distribution of the cone crusher becomes more stable after intelligent control is added, with the variance of the proportion of cumulative gradation at 15 mm decreased from 34.3 to 14.4. These results indicated that the developed adaptive control system effectively controls the fine processing of coarse aggregates and significantly improves the quality of aggregate crushing and processing.
{"title":"Adaptive control method and experimental study of cone crusher based on aggregate online detection","authors":"Huaiying Fang, Xiaosheng Ji, Jianhong Yang, Yuxuan Yang, Tianchen Ji, Chaoming Wei","doi":"10.37190/ppmp/188759","DOIUrl":"https://doi.org/10.37190/ppmp/188759","url":null,"abstract":"The size of the discharge outlet of a cone crusher directly impacts the size of the aggregate produced. However, the discharge outlet is still adjusted manually, which has a significant error and affects production efficiency. For this reason, this study proposed an adaptive control method for cone crushers based on aggregate online detection. Firstly, the aggregate image was segmented using an instance segmentation model and the anchor and structure of the model were optimised. Then, this study proposed an evaluation method for quickly and accurately assessing the overall segmentation effect of network models. By comparing the results with those before optimisation, the accuracy of the optimised network model was improved from 0.923 to 0.940. Finally, an adaptive control experiment was conducted based on the online aggregate detection results. The experimental results showed that the discharge particle size distribution of the cone crusher becomes more stable after intelligent control is added, with the variance of the proportion of cumulative gradation at 15 mm decreased from 34.3 to 14.4. These results indicated that the developed adaptive control system effectively controls the fine processing of coarse aggregates and significantly improves the quality of aggregate crushing and processing.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"34 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water quality, particularly hardness, plays an important role in affecting the floatability of minerals as it interferes with the chemical/electro-chemical characteristics of mineral surfaces and their interactions with flotation reagents. It could become unpredictable when water sources characterized by different calcium or magnesium ion distributions were involved. This study aimed to identify the role of Ca2+/Mg2+ ions in the recycled water on the cationic reverse flotation selectivity of iron oxides through a series of bench/micro flotation tests, zeta potential, powder contact angle, and Fourier Transform Infrared (FTIR), etc. The results pointed out that the use of recycled tailing water deteriorates the flotation selectivity and dilutes the concentrates. This can be largely attributed to the presence of Ca2+ ions at higher concentrations as they induce a drop in the Fe recovery and an increase in SiO2 content while an increase in the content of Mg2+ ions seems to have little effect on the quality of concentrate. As evidenced by the data from micro-flotation, powder contact angle, zeta potentials, and FTIR, a hydrophilic colloidal layer formed by Ca-based hydrolyzed compounds, such as Ca(OH)+ or, CaCO3(s), etc., on quartz could change its zeta potentials and disturb its interactions with a cationic collector. They also play a role in weakening the flocculation of starch on hematite probably by pre-locking the acidic groups on the starch remnants and contracting their configurations, thus preventing their adsorption on mineral surfaces. However, magnesium ions seem to be beneficial to in strengthening the flocculation of starch on hematite as magnesium-based species could act as adsorption bridges of between starch and mineral surfaces.
{"title":"Effects of Ca2+/Mg2+ ions in recycled water on the reverse flotation properties of iron oxides","authors":"Min Tang, Yan Wu, Jiahao Fu","doi":"10.37190/ppmp/188465","DOIUrl":"https://doi.org/10.37190/ppmp/188465","url":null,"abstract":"Water quality, particularly hardness, plays an important role in affecting the floatability of minerals as it interferes with the chemical/electro-chemical characteristics of mineral surfaces and their interactions with flotation reagents. It could become unpredictable when water sources characterized by different calcium or magnesium ion distributions were involved. This study aimed to identify the role of Ca2+/Mg2+ ions in the recycled water on the cationic reverse flotation selectivity of iron oxides through a series of bench/micro flotation tests, zeta potential, powder contact angle, and Fourier Transform Infrared (FTIR), etc. The results pointed out that the use of recycled tailing water deteriorates the flotation selectivity and dilutes the concentrates. This can be largely attributed to the presence of Ca2+ ions at higher concentrations as they induce a drop in the Fe recovery and an increase in SiO2 content while an increase in the content of Mg2+ ions seems to have little effect on the quality of concentrate. As evidenced by the data from micro-flotation, powder contact angle, zeta potentials, and FTIR, a hydrophilic colloidal layer formed by Ca-based hydrolyzed compounds, such as Ca(OH)+ or, CaCO3(s), etc., on quartz could change its zeta potentials and disturb its interactions with a cationic collector. They also play a role in weakening the flocculation of starch on hematite probably by pre-locking the acidic groups on the starch remnants and contracting their configurations, thus preventing their adsorption on mineral surfaces. However, magnesium ions seem to be beneficial to in strengthening the flocculation of starch on hematite as magnesium-based species could act as adsorption bridges of between starch and mineral surfaces.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140992959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
XianWu Huang, Yuxiao Wang, ZhiHong Zhu, Haili Shang, Zhao Cao
Collecting information on the flotation foam characteristics is important for controlling flotation production conditions. Foam images acquired during coal slurry flotation are affected by factors such as ambient lighting, contributing to uneven grayscale images with low brightness and contrast. Brightness enhancement of foam images is often required when using network models to extract feature information from the images. The paper proposes a foam image brightness enhancement algorithm based on a multiscale convolutional neural network. The method employs a skip connection structure based on a summation connection design based on logarithmic functions and introduces a loss function based on logarithmic transformation in the network. At the same time, branching networks of different complexity are designed in the network to further help alleviate the gradient vanishing problem. The experimental results show that when evaluating the quality of images after brightness enhancement of foam images and the public dataset MIT, the numerical results of using the proposed skip connection structure in the proposed network are overall better than using the resblock structure, and the proposed loss function is better than is better than using the L2 loss function. The proposed network greatly improves the visual effect of flotation foam images and lays the foundation for feature extraction of flotation foam images and intelligent flotation production.
收集有关浮选泡沫特性的信息对于控制浮选生产条件非常重要。在煤泥浮选过程中获取的泡沫图像会受到环境光线等因素的影响，导致图像灰度不均匀，亮度和对比度较低。在使用网络模型从图像中提取特征信息时，通常需要增强泡沫图像的亮度。本文提出了一种基于多尺度卷积神经网络的泡沫图像亮度增强算法。该方法采用了基于对数函数求和连接设计的跳转连接结构，并在网络中引入了基于对数变换的损失函数。同时，在网络中设计了不同复杂度的分支网络，以进一步帮助缓解梯度消失问题。实验结果表明，在对泡沫图像和公共数据集 MIT 进行亮度增强后的图像质量评估时，在所提出的网络中使用所提出的跳转连接结构的数值结果总体上优于使用 resblock 结构的结果，所提出的损失函数也优于使用 L2 损失函数的结果。提出的网络大大改善了浮选泡沫图像的视觉效果，为浮选泡沫图像的特征提取和智能浮选生产奠定了基础。
{"title":"Coal slurry foam image enhancement based on multiscale convolutional network","authors":"XianWu Huang, Yuxiao Wang, ZhiHong Zhu, Haili Shang, Zhao Cao","doi":"10.37190/ppmp/188277","DOIUrl":"https://doi.org/10.37190/ppmp/188277","url":null,"abstract":"Collecting information on the flotation foam characteristics is important for controlling flotation production conditions. Foam images acquired during coal slurry flotation are affected by factors such as ambient lighting, contributing to uneven grayscale images with low brightness and contrast. Brightness enhancement of foam images is often required when using network models to extract feature information from the images. The paper proposes a foam image brightness enhancement algorithm based on a multiscale convolutional neural network. The method employs a skip connection structure based on a summation connection design based on logarithmic functions and introduces a loss function based on logarithmic transformation in the network. At the same time, branching networks of different complexity are designed in the network to further help alleviate the gradient vanishing problem. The experimental results show that when evaluating the quality of images after brightness enhancement of foam images and the public dataset MIT, the numerical results of using the proposed skip connection structure in the proposed network are overall better than using the resblock structure, and the proposed loss function is better than is better than using the L2 loss function. The proposed network greatly improves the visual effect of flotation foam images and lays the foundation for feature extraction of flotation foam images and intelligent flotation production.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"14 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141006016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaofeng Zhang, Qi Li, Wenqing Qin, Cheng Liu, Siyuan Yang
It is challenging to separate fluorite from calcite due to their same calcium activated sites on their surfaces. The copolymer of maleic and acylic acid (PMAA) was used to inhibit the calcite in the flotation of fluorite. Micro-flotation results exhibited that sodium oleate (NaOl) had a good ability to collect fluorite and calcite in the scope of pH 7-10. The PMAA treatment prior to NaOl selectively depressed the floatability of calcite while allowed the flotation of fluorite, and the artificial minerals mixture plotted that fluorite/calcite could be effectively separated in the presence of PMAA/NaOl. Zeta potential results suggested that NaOl collector was absorbed on the PMAA-conditioned calcite surface but did not adsorb on the PMAA-conditioned fluorite surface. XPS results and calculational chemistry revealed the chemical interaction occurred between calcite surface and PMAA which was attributed to the calcium ions of calcite surface interacting with -COOH group of PMAA.
{"title":"Evaluation of a novel depressant PMAA for the separation of fluorite from calcite using NaOl as a collector","authors":"Xiaofeng Zhang, Qi Li, Wenqing Qin, Cheng Liu, Siyuan Yang","doi":"10.37190/ppmp/188272","DOIUrl":"https://doi.org/10.37190/ppmp/188272","url":null,"abstract":"It is challenging to separate fluorite from calcite due to their same calcium activated sites on their surfaces. The copolymer of maleic and acylic acid (PMAA) was used to inhibit the calcite in the flotation of fluorite. Micro-flotation results exhibited that sodium oleate (NaOl) had a good ability to collect fluorite and calcite in the scope of pH 7-10. The PMAA treatment prior to NaOl selectively depressed the floatability of calcite while allowed the flotation of fluorite, and the artificial minerals mixture plotted that fluorite/calcite could be effectively separated in the presence of PMAA/NaOl. Zeta potential results suggested that NaOl collector was absorbed on the PMAA-conditioned calcite surface but did not adsorb on the PMAA-conditioned fluorite surface. XPS results and calculational chemistry revealed the chemical interaction occurred between calcite surface and PMAA which was attributed to the calcium ions of calcite surface interacting with -COOH group of PMAA.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141013407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bauxite tailings slurry is a type of solid waste produced in the process of bauxite washing and beneficiation. It has poor engineering properties, that is, self-consolidation settlement unusually cannot be completed during several decades. To investigate the sedimentation properties of bauxite tailings, bauxite tailings slurry, phyllite residual soil, and kaolinite, we conduct sedimentation tests on these materials in varying pH and salt solution environments. The influence mechanism of the surface electrical properties of clay particles on the settlement of tailings slurry is investigated using the zeta potential test. The findings reveal that increases in the cation concentration and valence state lead to compression of the electric double layer on the surface of three types of soil particles, resulting in a decline in the repulsive potential energy and an increase in the gravitational potential energy. This in turn contributes to a reduction in the settling stable void ratio. As the pH increases, the zeta potentials of the three soils gradually decrease from positive to negative. A change in the pH at the isoelectric point, PZCedge, triggers the transformation of the kaolinite mineral arrangement. When the pH is either greater than or less than the isoelectric point, an increase or decrease in the pH results in expansion of the electric double layer of the clay particles and an increase in the pore content. The results of this study suggest that bauxite tailings mud is more likely to settle in an acidic environment than in an alkaline environment, thus an acidic settling environment should be utilized for bauxite tailings produced in industrial production.
{"title":"Influence of pH and salt solution on the sedimentation properties of fine bauxite tailings","authors":"Haihao Yu, Zhixiao Bai","doi":"10.37190/ppmp/186326","DOIUrl":"https://doi.org/10.37190/ppmp/186326","url":null,"abstract":"Bauxite tailings slurry is a type of solid waste produced in the process of bauxite washing and beneficiation. It has poor engineering properties, that is, self-consolidation settlement unusually cannot be completed during several decades. To investigate the sedimentation properties of bauxite tailings, bauxite tailings slurry, phyllite residual soil, and kaolinite, we conduct sedimentation tests on these materials in varying pH and salt solution environments. The influence mechanism of the surface electrical properties of clay particles on the settlement of tailings slurry is investigated using the zeta potential test. The findings reveal that increases in the cation concentration and valence state lead to compression of the electric double layer on the surface of three types of soil particles, resulting in a decline in the repulsive potential energy and an increase in the gravitational potential energy. This in turn contributes to a reduction in the settling stable void ratio. As the pH increases, the zeta potentials of the three soils gradually decrease from positive to negative. A change in the pH at the isoelectric point, PZCedge, triggers the transformation of the kaolinite mineral arrangement. When the pH is either greater than or less than the isoelectric point, an increase or decrease in the pH results in expansion of the electric double layer of the clay particles and an increase in the pore content. The results of this study suggest that bauxite tailings mud is more likely to settle in an acidic environment than in an alkaline environment, thus an acidic settling environment should be utilized for bauxite tailings produced in industrial production.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":" 120","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140221244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The rare earth molten salt electrolytic slag (REMSES) has recently attracted significant attention due to its potential environmental hazards and high content of rare earths and lithium, leading to a surge in recycling efforts. In this study, we propose and demonstrate a novel and straightforward process for the simultaneous extraction of rare earths and lithium from REMSES through lime transformation and sulfuric acid leaching at low temperatures. Firstly, during the lime transformation process, REMSES is converted into hydroxides that can be easily dissolved in acids. Secondly, REEs and Li present in the slag are co-extracted using a conditional sulfuric acid leaching method, resulting in 95.72% REEs leaching efficiency and 99.41% Li leaching efficiency under optimal conditions. Finally, REEs and Li in the solution are precipitated using oxalic acid and trisodium phosphate with precipitation efficiencies of 99.02% for REEs and 94.85% for Li respectively. This innovative process enables the conversion of REEs and lithium from REMSES into high-purity products (a mixture of REOs with 99.31% purity; Li3PO4 with 98.93% purity), thereby facilitating their valuable utilization.
{"title":"Recovery of rare earths and lithium from rare earth molten salt electrolytic slag by lime transformation, co-leaching and stepwise precipitation","authors":"Xinglan Li, Peidi Luo, Zishuai Liu, Xuekun Tang, Baqun Zhang, Jiangfeng Guo","doi":"10.37190/ppmp/186333","DOIUrl":"https://doi.org/10.37190/ppmp/186333","url":null,"abstract":"The rare earth molten salt electrolytic slag (REMSES) has recently attracted significant attention due to its potential environmental hazards and high content of rare earths and lithium, leading to a surge in recycling efforts. In this study, we propose and demonstrate a novel and straightforward process for the simultaneous extraction of rare earths and lithium from REMSES through lime transformation and sulfuric acid leaching at low temperatures. Firstly, during the lime transformation process, REMSES is converted into hydroxides that can be easily dissolved in acids. Secondly, REEs and Li present in the slag are co-extracted using a conditional sulfuric acid leaching method, resulting in 95.72% REEs leaching efficiency and 99.41% Li leaching efficiency under optimal conditions. Finally, REEs and Li in the solution are precipitated using oxalic acid and trisodium phosphate with precipitation efficiencies of 99.02% for REEs and 94.85% for Li respectively. This innovative process enables the conversion of REEs and lithium from REMSES into high-purity products (a mixture of REOs with 99.31% purity; Li3PO4 with 98.93% purity), thereby facilitating their valuable utilization.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"129 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140223570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miguel Maldonado, Ignacio Ramos, Alonso Pinto, Cesar O Gomez
The impact of air distribution on the metallurgical performance of a flotation bank operating with a mineral slurry having a moderate and high frother concentration is assessed. A flotation bank of two and three 5L Denver cells was implemented, and air flow was distributed down the bank as increasing and decreasing profiles. It was observed that when operating the bank configurations with a moderate frother concentration (10 ppm DF 400) the increasing profile provided the highest Cu enrichment ratio at the expense of a slight reduction in Cu recovery. This increase in selectivity was mainly due to a significant reduction in the water recovery and mass-pull in the first cell. When the bank operated with a high frother concentration, i.e., well beyond the CCC, a significant increase in water recovery was observed, producing a significant loss in selectivity that could not be compensated by air profiling.
{"title":"Effect of air profiling and frother concentration on a flotation bank performance","authors":"Miguel Maldonado, Ignacio Ramos, Alonso Pinto, Cesar O Gomez","doi":"10.37190/ppmp/186274","DOIUrl":"https://doi.org/10.37190/ppmp/186274","url":null,"abstract":"The impact of air distribution on the metallurgical performance of a flotation bank operating with a mineral slurry having a moderate and high frother concentration is assessed. A flotation bank of two and three 5L Denver cells was implemented, and air flow was distributed down the bank as increasing and decreasing profiles. It was observed that when operating the bank configurations with a moderate frother concentration (10 ppm DF 400) the increasing profile provided the highest Cu enrichment ratio at the expense of a slight reduction in Cu recovery. This increase in selectivity was mainly due to a significant reduction in the water recovery and mass-pull in the first cell. When the bank operated with a high frother concentration, i.e., well beyond the CCC, a significant increase in water recovery was observed, producing a significant loss in selectivity that could not be compensated by air profiling.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"57 S271","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140224053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：