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Reverse flotation is a commonly used method for separating carbonate minerals from apatite, but its application to phosphate beneficiation coarse rejects, which are low in P2O5, is often costly due to the high collector dosages used. This study aimed to explore alternative techniques for preconcentration before flotation to improve recovery rates and reduce costs. Our investigation focused on dense medium separation and acid leaching. Dense medium separation, conducted at a cut-off density of 2.76, yielded a preconcentrate with 27% P2O5 and a recovery rate of 90%. The feed material had an initial P2O5 content of 20.52% and a particle size range of +40 µm to −4 mm. In contrast, acid leaching, employing an 8% acetic acid solution over 35 min, yielded a concentrate with 29.11% P2O5, an LOI of 8.99%, and a recovery rate of 100% from an ore fraction [400–200 µm] with an initial P2O5 content of 22.82% and an LOI of 15.78%. Furthermore, integrating flotation and leaching resulted in a concentrate with 32.27% P2O5 and a recovery rate of 98.38%. These findings suggest that combining acid leaching with flotation can enhance P2O5 recovery and reduce processing costs for low-grade phosphate ores. [ABSTRACT FROM AUTHOR]

Phosphorus is a vital nutrient essential for plant development and numerous biological functions. It is primarily obtained from phosphate rock through a process known as beneficiation. However, the declining reserves of high-grade phosphate rock, combined with the uneven global distribution of phosphorus and the environmental impacts associated with its extraction and use, highlight the need for a more efficient management of this critical resource. Increasingly, alternative sources of phosphorus, such as extraction from waste materials, are being explored. This study aims to assess the feasibility of recovering phosphorus from coarse rejects produced during phosphate beneficiation at a phosphate washing plant. Before conducting laboratory preparation and reverse flotation tests, the sample underwent initial laboratory examination and analysis. The sample was found to contain low-grade apatite minerals with a phosphorus pentoxide (P2O5) content ranging from 19% to 20%. Additionally, carbonate and quartz were identified as the primary accompanying minerals. Flotation experiments yielded a phosphorus recovery rate of 29% P2O5, with a carbonation rate of 1.6. Although this recovery rate is slightly below the commercial phosphate standard of 30% P2O5, it represents a significant improvement and demonstrates potential for further optimization to meet industry requirements. Consequently, these coarse discarded rejects could serve as a supplementary source of phosphorus in the future. [ABSTRACT FROM AUTHOR]

Taking Anning Phosphate Mine in Yunnan Province as the research object, this study focuses on the low P2O5 grade (20.00%), high MgO content, complex ore composition, useful minerals such as apatite, and main gangue minerals such as dolomite, quartz, and other silicate minerals. Taking advantage of the characteristic that different numbers of unsaturated bonds contained in mixed unsaturated fatty acids, which have higher solubility than single unsaturated fatty acids, can improve the hydrophobicity of dolomite, a compound mixed fatty acid reagent (ZP) was prepared by compounding oleic acid, linoleic acid, and linolenic acid at a ratio of 50% + 30% + 20%, and this reagent was used as collectors for reverse flotation of the phosphate ore. The influence of collectors on the wettability of dolomite and the effect of compound agent ZP on the particle size of collector micelles were studied. Based on single-factor experimental research, both open-circuit and closed-circuit tests were conducted. The results show that: the composite agent ZP had a better hydrophobicity effect on dolomite than that of single oleic acid reagent. When the dosage of ZP was 200 mg/L, the contact angle of dolomite could reach 74.62°. ZP collector has a higher solubility than oleic acid, which can improve flotation efficiency; By using a process of one coarse selection, three fine selections, and three sweep selections for reverse flotation, a closed-circuit test can ultimately obtain concentrate indicators with a P2O5 yield of 59. 23%, P2O5 grade of 28.36%, MgO grade of 0.63%, and P2O5 recovery rate of 80.16%. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to enhance the reverse flotation effect of hematite, dodecyl trimethyl ammonium chloride (DTAC) and a mixed anionic/cationic collector of DTAC and tall oil were selected for flotation studies on quartz and hematite. Surface tension tests, FT-IR, XPS analysis, and molecular dynamics (MD) simulations were also conducted in order to investigate the interaction mechanism of the mixed collector on the quartz surface. The results revealed that, at a natural pH (approximately 7.0) and 298 K, and with a dosage of 20 mg/L for the mixed collector (mDTAC:mtall oil = 3:1) and 4 mg/L for causticized starch, the recovery rates of quartz and hematite were 94.67% and 8.69%, respectively. Compared to the use of a single DTAC, the mixed DTAC/tail oil collector enhanced the flotation effect under constant variables. Additionally, a comparison of temperature and surface tension for monomineral flotation and artificially mixed ore flotation tests showed that the mixed collector was less influenced by temperature, compared to the single DTAC, and exhibited good resistance and more effective separation of quartz and hematite at lower temperatures. The analysis of FT-IR, XPS, and MD simulations revealed that the single DTAC collector primarily adsorbed onto quartz through physical adsorption and hydrogen bonding, while the combination of tall oil and DTAC enhanced the adsorption of the collector on the quartz surface. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The TFe grade of the mixed magnetic concentrate from a Liaoning iron ore processing plant is 53.92%. The main iron minerals are magnetic/hematite and the main gangue minerals are quartz. TD-II collector is used for reverse flotation in tins concentrator, but the pulp temperature Is 40 °C, winch leads to waste of resources. In order to improve the production index, a new low temperature collector DZ with multipolar base independently developed by Northeastern University Is used for reverse flotation of the mixed magnetic concentrate in thus concentrator. The effects of DZ dosage, pulp pH value, flotation temperature, starch dosage and CaO dosage on the flotation behavior of the mixed magnetic separation concentrate were investigated. For the mixed magnetic concentrate with TFe grade 53.92%, a new low temperature collector DZ was used under the conditions of flotation temperature 15 ± 2 °C, pulp pH value 9, depressant starch dosage 750 g/t, collector DZ dosage 150 g/t, and no activator was added. The flotation lockedcycle test of "one roughing, two cleanings and three scavergings" showed that a flotation concentrate with TFe grade 65.24% and iron recovery of 93.03% can be obtained, whereas under the conditions of flotation temperature 40 ± 2°C, pulp pH value 11, starch dosage 900 g/t, CaO dosage 900 g/t and collector TD-II dosage 350 g/t, a flotation concentrate with TFe grade 65.47% and iron recovery 90.71% can be obtained through the lockedcycle flotation test of "one roughing, one cleanings and three scavengings". The product inspections for the flotation concentrates obtained from the new low-temperature collector DZ and from the field reagent TD-II were carried out. By comparing the flotation results with the product inspection, t can be found that the new low-temperature collector DZ is a high-efficiency and high-selectivity low-temperature flotation collector, which can effectively solve the problem of energy waste in the reverse flotation process of the concentrator, save the beneficiation cost and improve the resource utilization efficiency. [ABSTRACT FROM AUTHOR]

Super iron concentrate, as a new type of high value-added material, has enormous development potential. The TFe grade of a magnetite ore in Gongchangling is 60.96%. The content of the main impurity SiO2 in the ore Is 33.21%, and the content of harmful elements P and S is relatively low. The iron element mainly exists in magnetite, accounting for 95.05%. The particle size of magnetite in the ore is coarse, mainly distributed in the size range + 0.074 mm, and the distribution rate being 82.37%. Magnetite in the sample occurs mainly produced in form of free particles. Some line-grained quartz embedded in magnetite in the form of inclusions, reverse inclusions and line veins, which difficult to be completely liberated. In order to realize a high value utilization of the ore, the experimental study on the preparation of super iron concentrate has been carried out. A processing flowsheet of "stage grinding & stage magnetic separation-reverse Rotation to desiliconization" has been adopted. Under the process parameters of the first-stage grinding fineness of 65% - 0.074 mm, the second-stage grinding fineness of 90% -0.025 mm, and the dosage of roughing and cleaning collectors in reverse notation 25 g/t. A high quality super iron concentrate wkh TFe grade 72.35% and Fe recovery 81.03%, SiO2 content 0.17%, and acid insoluble substance of 0.19% and trace amount of other impurities has been obtained. In addition, a high purity iron concentrate wkh TFe grade 71.37% and Fe recovery 6.07%, as well as an ordinary iron concentrate wkh TFe grade of 60.26% and Fe recovery of 6.71% have also been obtained. This technology provided a basis for the high value and grading utilization of the magnetite ore. [ABSTRACT FROM AUTHOR]

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 prelocking 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. [ABSTRACT FROM AUTHOR]

The TFe grade of an ordinary magnetite in Hebei Province is 65.25%, and the ore properties and structure are simple, which has the potential to prepare ultrapure iron concentrate. In this study, the process mineralogy of the raw ore was studied by multi-element and X-ray diffraction pattern, phase analysis and other methods, and the purification test was carried out on this basis. The results show that after the rough separation of the raw ore with a weak magnetic separation, the magnetic separation column concentrate with a TFe grade of 71.31% and the iron tailings with a TFe grade of 68.12% and a yield of 3.32% were obtained by weak magnetic separation and re-separation and magnetic separation column selection with a grinding fineness of -0.038 mm accounting for 85%. By further investigating the influence of the pharmaceutical system and technological process on the grading and recovery of iron ore concentrate, a suitable pharmaceutical system was determined. Then, the magnetic separation column concentrate was tested by 1 coarse and 3 fine reverse flotation silica reduction process, and finally the ultrapure iron concentrate containing TFe grade of 71.95% and the comprehensive recovery rate of 80.50% was obtained, and the TFe grade of flotation tailings was 68.17%, which met the standard of ordinary iron ore concentrate. Through the analysis of the chemical composition of the samples and the determination of the residual agent, it is further proved that the process can realize the preparation of ultrapure iron concentrate. Under the condition of a tail-throwing rate of 10.79%, 73.04% of the raw ore sample is converted into ultra-pure iron concentrate, which has important guiding significance for the preparation of ultra-pure iron concentrate in this area, and also provides a certain reference value for the research on the preparation of ultra-pure iron concentrate from magnetite in other parts of China. [ABSTRACT FROM AUTHOR]

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This is an article in the field of mining engineering. Ca2+ and Mg2+ are easily dissolved from fluorapatite and dolomite in the acid medium of reverse flotation, and there is a "cumulative effect" in the process of backwater circulation, which has an adverse effect on the flotation indexes. Taking fluorapatite, dolomite and quartz as the research objects, the effect of different recycle times of backwater on the flotation recovery of three single minerals was studied. The results showed that when pH value was 5, the recovery difference between dolomite and fluorapatite decreased from 72.21% to 64.19%, and the recovery of quartz maintained at about 10%; When the number of cycles reached 5, the recovery difference between dolomite and fluorapatite slightly increased to 69.74%, and the recovery of quartz slightly decreased to 11.22%. In this study, the mechanism of dissolved ions in backwater for three kinds of single minerals was revealed by measuring the number of dissolved ions, zeta potential of mineral surface and ions adsorption capacity of mineral surface under backwater circulation system.

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This is an essay in the field of mineral processing engineering. The process mineralogy study of a manganese carbonate ore from Hubei Province shows that the main valuable minerals of this ore are kutnohorite, calcimangite and a small amount of pyrolusite with fine monomer dissociation, the gangue minerals are dolomite, quartz and mica. The present manganese carbonate ore belongs to refractory low-grade manganese carbonate ore with high calcium and phosphorus. There are few studies on this type of manganese ore, thereby the treatment process is complicated with the low product grade and the high cost. The mineral processing results of this study reveal that, under the condition of 90% of the products from stage grinding to -74 μm, manganese minerals were recovered by magnetic separation through the process of cleaning mixed concentrate with one roughing and one cleaning tailings, and further enriched by one-stage reverse flotation desilication. Finally, a manganese concentrate with Mn grade of 27.10%, P/Mn ratio of 0.009 and Mn recovery of 58.21% was obtained, which can be mixed with other low-phosphorus manganese concentrates as the metallurgical industrial raw material to meet the industrial requirements.

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dolomite, a prominent calcium-bearing gangue mineral found in carbonate-type zinc oxide ores, poses a significant challenge for effective flotation separation alongside smithsonite due to their highly similar surface properties. The present study explores the potential of 2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctanoic acid (2-DMPT) as a collector for the reverse flotation of smithsonite from dolomite. Micro-flotation experiments indicated that saponified 2-DMPT exhibited superior collecting ability and selectivity for dolomite over smithsonite under highly alkaline conditions. Specifically, the flotation recovery of dolomite reached 62%, whereas only 6% of smithsonite was recovered in the flotation foam products. Zeta potential and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) analysis revealed that changes in pH values had minimal influence on the collector's adsorption onto dolomite, while significantly hindering its adsorption on the smithsonite surface. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis showed that 2-DMPT could form hydrophobic complexes with the active Ca2+ sites on the dolomite surface at pH 11.5. However, the interaction between smithsonite and carboxylic groups of 2-DMPT under the same conditions was relatively weaker, facilitating their reverse flotation separation. As a result, 2-DMPT shows promise as a potential collector for the reverse flotation process, effectively removing dolomite from smithsonite and reducing acid consumption in subsequent acid-leaching processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to enhance the reverse flotation effect of hematite, dodecyl trimethyl ammonium chloride (DTAC) and a mixed anionic/cationic collector of DTAC and tall oil were selected for flotation studies on quartz and hematite. Surface tension tests, FT-IR, XPS analysis, and molecular dynamics (MD) simulations were also conducted in order to investigate the interaction mechanism of the mixed collector on the quartz surface. The results revealed that, at a natural pH (approximately 7.0) and 298 K, and with a dosage of 20 mg/L for the mixed collector (mDTAC:mtall oil = 3:1) and 4 mg/L for causticized starch, the recovery rates of quartz and hematite were 94.67% and 8.69%, respectively. Compared to the use of a single DTAC, the mixed DTAC/tail oil collector enhanced the flotation effect under constant variables. Additionally, a comparison of temperature and surface tension for monomineral flotation and artificially mixed ore flotation tests showed that the mixed collector was less influenced by temperature, compared to the single DTAC, and exhibited good resistance and more effective separation of quartz and hematite at lower temperatures. The analysis of FT-IR, XPS, and MD simulations revealed that the single DTAC collector primarily adsorbed onto quartz through physical adsorption and hydrogen bonding, while the combination of tall oil and DTAC enhanced the adsorption of the collector on the quartz surface.

We analyzed a novel cationic collector using chemical plant byproducts, such as cetyltrimethylammonium bromide (CTAB) and dibutyl phthalate (DBP). Our aim is to establish a highly effective and economical process for the removal of quartz from collophane. A micro-flotation test with a 25 mg·L−1 collector at pH value of 6–10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite. Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process (using a 0.4 kg·t−1 new collector at pH = 6) results in a collophane concentrate with 29.33wt% P2O5 grade and 12.66wt% SiO2 at a 79.69wt% P2O5 recovery, providing desirable results. Mechanism studies using Fourier transform infrared spectroscopy, zeta potential, and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite. The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite. The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min−1. This is considerably higher than that of a conventional cationic collector. [ABSTRACT FROM AUTHOR]

In order to realize the desilication of phosphate rock by reverse flotation, the selection of appropriate amine collectors and reasonable flotation conditions are the key to the desilication of phosphate rock by reverse flotation. Through flotation experiments, the collection effects of four different amine collectors, including fatty amines, amine ethers, ether amines and oxidized amines, on quartz were compared. The experiments show that different amine collectors have different flotation properties for collophanite at the same pH value. In weakly alkaline medium, the basic order of the collection capacity of fatty amine reagents for SiO2 is as follows: the flotation collection performance of coconut diamine for silicate minerals is better than that of n-octylamine, dodecylamine, coconut diamine and isothirteen amine, but the loss rate of phosphorus by isothirteen amine reagent is lower, followed by coconut diamine, dodecylamine, coconut oil amine and n-octylamine had greater loss of phosphorus. The collection capacity of amine ethers for SiO2 is as follows: the collection capacity of coconut amine polyoxyethylene ether for silicate minerals is stronger than that of dodecylamine polyoxyethylene ether, and the P2O5 loss rate of flotation tailings of dodecylamine polyoxyethylene ether is higher than that of coconut amine polyoxyethylene ether; The collection capacity of ether amine reagents for SiO2 is as follows: the collection capacity of isodecanetramine for silicate minerals is weaker than that of C10 ether amine, and the loss rate of P2O5 of isodecanetramine flotation tailings is higher than that of C10 ether grease; The test results show that the flotation performance of the same type of amine reagent is basically similar, and there are some small differences. The collection capacity of fatty diamine with the same carbon chain composition for collophanite is stronger than fatty monoamine. The basic order of flotation performance from strong to weak is diamine > monoamine > ether amine > amine ether > oxide amine.

In terms of the iron concentrate, the TFe grade is 65.50% and mainly gangue is quartz with the content of 4.82%. Additionally, the content of harmful impurity, sulphur and phosphor, is low. Following grinding-magnetic separationis able to enhance the mFe content and grade of concentrate for the reason that the content of mFe is 98.74% and other iron phase is nonmagnetic. The process of prescreening-grinding-classification-magnetic separation-reverse flotation is adopted to the super-grade iron concentrate experimental study of an iron concentrate from Sichuan. When the screen size is 0.074 mm and grinding fitness is -0.038 mm 90%, using the thenanoceramic balls as milling medium, super-grade iron concentrate with yield 24.23%, TFe grade 71.71%, quartz content of 0.16%, acid insoluble content of 0.16% could be obtained. In the process, the usage of corn starch is 600 g/t and the usage of collector is 100+50+50 g/t. The process is reasonable and significantly feasibility with low energy consumption and simple reagent system. Additionally, the process could obtain normal iron concentrate with the yield of 72.25% and TFe grade of 65.47% which could be considered as good iron concentrate product to sell.

Through the single mineral flotation test, the flotation behavior of magnesite and dolomite in the dodecylamine flotation system and the influence of the regulator Fe3+ on the floatability of the two minerals were studied. Based on Fourier Infrared Spectroscopy (FTIR) and contact angle test, the mechanism of Fe3+ was studied. The flotation test results show that in the dodecylamine system, under the natural pH condition of the pulp, the floatability of dolomite is better than that of magnesite. There is a certain floatation difference between magnesite and dolomite, and the addition of a small amount of Fe3+ significantly improves the floatation difference of the two minerals. Infrared spectroscopy test results show that the adsorption of dodecylamine on the surface of dolomite is mainly electrostatic adsorption, dolomite CO32− out-of-plane bending vibration and CO32− in-plane bending vibration are almost unchanged, and -CH3 and -CH2 are symmetrical and asymmetrical. The peak value of extensional vibration increases. The contact angle test results show that the addition of a small amount of Fe3+ enhances the hydrophobicity of dolomite, which has the effect of activating dolomite.

A small amount of magnetite is associated with the Shizhuyuan Tungsten Molybdenum Bismuth Fluorite polymetallic ore, the total iron grade is 7.15%, the iron grade in the magnetite is 1.68%, which is 23.50% of the total iron. “Shizhuyuan method” is used in the whole beneficiation process of the tungsten-molybdenum-bismuth-fluorite polymetallic ore, in which the magnetite is preferentially removed by medium magnetic separation before recovering tungsten, molybdenum, bismuth, fluorite and other useful minerals, in order to avoid the interference of magnetite to the subsequent separation operation, the coarse magnetite concentrate is produced. In order to further improve the comprehensive utilization rate of mineral resources and excavate the new economic growth point of the mining enterprises, it is decided to carry out the experimental study on beneficiation of coarse concentrate of magnetite ore. Through the study on the properties of the magnetite coarse concentrate, it is found that the magnetite coarse concentrate has fine particle size distribution and high magnetic sulfur content. In order to improve the quality of magnetite concentrate, the grade of iron in magnetite concentrate must be raised, and the sulfur content in magnetite concentrate must be reduced. To raise the iron grade of magnetite concentrate, fine grinding method is used to separate magnetite from its monomer, and then the iron grade of magnetite concentrate can be raised by weak magnetic separation, while to reduce the sulfur content of magnetite concentrate, reverse flotation is generally used to remove sulfur, it is necessary to find out the process flow and parameters of reverse flotation desulfurization suitable to the property of the ore in order to ensure the efficient removal of magnetic sulfur from magnetite ore. After the systematic experimental study on beneficiation, it is determined that the final magnetite concentrate quality can be greatly improved by first demagnetizing, then by reverse flotation, and then by stage grinding. When the magnetite rough concentrate grade TFe 38.19% and S 4.51% , the final magnetite concentrate grade TFe 60.85% , S 0.99% and iron recovery 72.13% can be obtained. The process has been applied in the field, and good results have been achieved by optimizing the configuration of the field flow structure.

In view of the difficulty and low efficiency of fine hematite flotation, nanobubbles with special interfacial properties were applied to reverse the flotation of hematite to improve the flotation behavior and separation performance of fine particles. The Box-Behnken response surface method was used to design the experiments and optimize the reagent dosage for reverse nanobubble flotation of hematite from the flotation feed at Anqian Mineral Processing Plant by specifically analyzing the effect of each factor and the interactions between factors on the flotation performance. The results show that collector TD-Ⅱ and corn starch had more significant impacts on grade and recovery than lime and the interactions between starch, lime, and collector TD-Ⅱ had significant effects on iron grade. The iron recovery is 82.27 % and the iron grade is 67.32 % for the concentrate when 3.0 kg/t corn starch, 1.5 kg/t lime, and 0.78 kg/t collector TD-Ⅱ are added. The kinetic flotation experiments confirm that the introduction of nanobubbles in flotation can improve flotation kinetics and concentrate recovery. The application of the nanobubble flotation process will help resolve the difficulty in the efficient flotation of fine particles, which is of great significance to improving the technical performance indicators and economic benefits of the mineral processing plant. [ABSTRACT FROM AUTHOR]

In this study, the influence of activating treatment on the demineralization of a lignite sample utilizing the reverse flotation was studied. A lignite sample containing 42.09% ash, 0.86% sulfur, 38.46% volatile matter and 19.45% fixed carbon was used in experiments. Quartz, clay mineral, feldspar (plagioclase) mineral and mica mineral were determined as dominant minerals. The activation of gangue minerals (particularly quartz) using lead, tin, iron, and aluminum salts were performed. The influences of different parameters were investigated. Reverse flotation results demonstrated that a clean coal having 35.81% ash and 61.81% combustible yield could be gained in the usage of tin salt. [ABSTRACT FROM AUTHOR]

In this study, an optimized method was presented for the reverse quartz flotation in iron ore purification where sodium oleate (NaOL) was always selected as the collector due to its accessibility and economic benefits. Three alcohol ethoxylates, octylphenol ethoxylate (OP-10), nonylphenol ethoxylate (NP-10) and fatty alcohol ethoxylates (AEO-9) were introduced to improve the collecting performance of NaOL in the reverse flotation of quartz. It turned out that the addition of alcohol ethoxylates was helpful to increase the recovery of quartz in the flotation with the order of OP-10 > NP-10 > AEO-9. To characterize the adsorption of NaOL on activated quartz in different surfactant systems, Fourier-Transform Infrared Spectroscopy (FTIR) and Quartz Crystal Microbalance with Dissipation (QCM-D) were employed. Furthermore, the contact angles of the quartz surface that interacted with different surfactant systems were measured to investigate the synergy effect of NaOL and alcohol ethoxylates on the hydrophobicity of quartz. It turned out that alcohol ethoxylates promoted the adsorption of NaOL on the activated quartz, resulting in an increase in the hydrophobicity of quartz also in the order of OP-10 > NP-10 > AEO-9, which well explained the flotation results. Regular Solution Theory (RST) and the dilution effect based on the surface tension analysis were utilized to elucidate the synergy mechanism between NaOL and the alcohol ethoxylate. [ABSTRACT FROM AUTHOR]

Mineral flotation test， combined with laser particle size test， scanning electron microscope (SEM)， mineral surface potential and XPS (X-ray photoelectron spectroscopy) were used to study the behavior and mechanism of polyoxyethylene oxide (PEO) flocculation of fine kaolinite in the process of hematite reverse flotation. The flotation test showed that the addition of PEO improves the mineral recovery of kaolinite and the separation efficiency of artificial mixed ore， which is conducive to promoting the reverse flotation separation of hematite and kaolinite. The results of laser particle size test and SEM showed that PEO does not flocculate hematite， but flocculates kaolinite particles to increase their apparent particle size. Zeta-potential tests and XPS analysis indicated that chemical adsorption of PEO occurs on the surface of kaolinite particles， and its Zeta-potential is positively shifted. Therefore， PEO has certain guiding significance in the study of reverse flotation separation of hematite and kaolinite. [ABSTRACT FROM AUTHOR]

Purpose. In this work, the influence of flotation reagents on the separation yield of the phosphate-carbonate system is studied. The investigation is conducted by the reverse flotation process in double stage of the phosphate ores from the Jebel Onk deposit-Algeria. Methodology. The experimental part can be divided into three aspects, a mechanical preparation of the samples, and flotation tests in the first stage followed by a double flotation and, finally, characterization of the flotation products by different physicalchemical analysis techniques. Findings. Reverse flotation double stage process was applied on two classes of phosphate ores (C1: 40–250 and C2: 250–500 μm). The samples are constituted by phosphatic elements (apatite), cemented by a mixture of a great amount of dolomite with low amounts of quartz, clay and calcite. Flotation results showed that P2O5 recovery was higher for C2 compared to C1. Thus, oleic acid and double tartrate of sodium-potassium could be considered as the best reagent since the P2O5 recovery content corresponds to 29.27 and 31.25 % for C1 and C2, respectively. Compared to the oleic acid and pine oil reagent, the recoveries of P2O5 were 28.85 and 30.55 % for C1 and C2, respectively. However, when other reagents as (oleic acid + phosphoric acid) and (oleic acid + diesel fuel) were used, the recovered amount of P2O5 was found to be less important, 27.80 and 27.10 % for class C1, and 30.14 and 29.15 % for C2, respectively. Originality. During this study two main axes were discussed: the first one was the influence of flotation reagents on flotation of the first and second stages, the second one was to study the effect of grain size on the flotation yields. The flotation process has been shown to be effective both in terms of depressed phosphate elements in the phosphate concentrates and in gangue floated in the flotation tailings. It can be seen that the concentrate contents of around 32 % is achieved in P2O5 with superior recoveries of 99 %. Practical value. The results of analyses carried out on the flotation products showed, in most cases, that the streams are richer in phosphate elements (fluorapatite, carbonate hydroxylapatite, carbonate fluorapatite) and a low amount of carbonates (dolomite and calcite), unlike floating, mainly made up of dolomite with a small amount of phosphated elements. [ABSTRACT FROM AUTHOR]

To improve the magnesia removal effect of collophane and increase the P2O5 grade of phosphorus concentrate, the fatty acid collector mixed with sodium dodecyl sulfate (SDS) was used as the compound collector in reverse flotation for magnesia removal in acid system. Solution surface tension measurement, Zeta potential test and infrared spectrum analysis were conducted to analyze the intensified effect of compound collector for dolomite removal. The results showed that under the conditions of grinding fineness -0.074 mm accounted for 89.8%, sulfuric acid dosage 12.0 kg/t, phosphoric acid dosage 3.0 kg/t, SDS compound proportion 3%, collector dosage 1.0 kg/t, the P2O5 grade of concentrate is increased from 25.7% to 29.94%. SDS can reduce the surface tension of slurry, which is conducive to the formation and stability of flotation foam. Zeta potential became negative due to the compound collector adsorbed on the mineral surface. Moreover, the -CH2 antisymmetric stretching vibration peak originated from fatty acid and SDS were detected after the interaction of collectors with dolomite. The compound collector was effectively adsorbed on the surface of dolomite, enhancing the magnesium removal effect of collophane. [ABSTRACT FROM AUTHOR]

A study into the possible separation of feldspar from quartz in a Bangladesh river sand sample was undertaken with the aim of producing a high-grade quartz product for potential use in glassmaking. Flotation was used to upgrade two river sand concentrates, with sizings of +250 µm and −250 µm, from the Brahmaputra River. Feldspar was floated from quartz using dodecylamine as collector in an acidic circuit at pH 2–2.5 after a mica prefloat. For the −250 µm fraction, the best quality quartz product assayed 96.8 wt% SiO2 and 1.95 wt% Al2O3 with 46.7 wt% of the feed quartz recovered at a quartz content of 89.1 wt% quartz. A test on the +250 µm fraction, which was firstly ground then deslimed at 50 µm before mica and feldspar flotation stages, produced a quartz product assaying 99.5 wt% SiO2 and only 0.3 wt% Al2O3 with a quartz content of 98 wt%. [ABSTRACT FROM AUTHOR]

Lignite is extremely hydrophilic; thus it is difficult to upgrade its quality by conventional flotation. In this study, cetylpyridinium chloride monohydrate (CCM) was used as the collector for quartz. The effect of CCM dosage on reverse flotation of Shengli lignite was investigated by different slurry mixing methods. And the dissolution properties of CCM and its mechanism of collecting quartz were studied via surface tensitometer and FTIR. The flotation results show that, due to the strong hydrophilicity of Shengli lignite, the performance of direct flotation is poor. With reverse flotation, the yield of clean coal and the flotation perfection are obviously improved. Besides, the reverse flotation with the zero-conditioning is more efficient than the conventional one. FTIR results show that the adsorption of CCM barely change the functional groups of quartz, indicating that CCM was adsorbed on the surface of quartz through electrostatic adsorption to collect quartz. Meanwhile, CCM adsorption significantly reduces the content of hydroxyl oxygen-containing functional groups of quartz, leading to an increase of the content of hydrophobic groups such as long-chain alkyl. As a result, the hydrophobicity of quartz was improved, and the reverse flotation of lignite was promoted.

The former flotation process of Wangji Collophanite（Ph1）is direct-reverse flotation processes. In the production practice, there are some problems such as high grade of final tailings, low yield and recovery rate. In this paper, through test research and technological transformation, the original direct-reverse flotation processes was changed into single reverse flotation process, and the production process index was improved ,the recovery was improved by 9.78 percentages.

Different adsorption states of PASF on the quartz surface before and after UV irradiation. [Display omitted] • A photosensitive azo surfactant (PASF) can improve the whiteness and purity of phosphogypsum by flotation. • The cis–trans structures of PASF can be converted into each other under certain conditions. • The quartz surface appeared to be less hydrophilic compared to gypsum after PASF was dropped onto the surfaces. • After UV irradiation, the foaming ability of PASF decreased and the adsorption capacity of PASF on the quartz surface decreased. • When PASF is converted from a trans to a cis structure, it desorbs from the quartz surface for the large steric hindrance. Phosphogypsum (PG) is the main by-product of wet phosphoric acid production and has seriously polluted the environment. In this study, PG was purified by reverse flotation using a photosensitive azobenzene surfactant (PASF). After reverse flotation, the content of gypsum in PG increased from 89.16 % to 93.32 %, the whiteness of PG increased from 25.62 % to 60.9 %, and the content of quartz decreased from 4.87 % to 2.12 %. The Zeta potential of quartz and gypsum became positive after being treated with PASF, indicating that PASF enhanced the floatability of quartz and gypsum. The results of FTIR and XPS indicated that there were both electrostatic attraction and hydrogen bonding between PASF and quartz. Density functional theory (DFT) calculations indicated that the adsorption of PASF on the quartz surface was more stable than on the gypsum surface. Upon exposure to UV irradiation, the molecular structure of PASF was transformed from trans to cis. Meanwhile, the adsorption amount of PASF on the quartz surface was decreased and the rigidity of the corresponding adsorbed layer was increased. This work provides a method to purify PG waste, which is important for the comprehensive utilization of PG. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic separation, flotation, and alkali leaching were conducted in the process. • The concentrate's Fe grade increased from 65.56% to 72.30% following beneficiation. • High-purity magnetite with a purity of 99.91% was prepared. • Implementing this preparation process helps reduce CO 2 emissions in China. In pursuit of environmental protection and green, low-carbon economic development, China has proposed the dual-carbon strategies of carbon peak and carbon neutrality. To achieve the dual-carbon goals, traditional steel metallurgical production processes are gradually shifting towards green and low-carbon hydrogen metallurgical processes. However, hydrogen metallurgical processes have strict requirements for raw materials and typically require the utilization of high-grade iron concentrates. The scarcity of high-grade iron ore in China severely constrains the development of hydrogen metallurgical processes. Therefore, this study proposes the utilization of ordinary magnetite concentrate to produce high-grade magnetite. Comprehensive analytical methods, including chemical analysis, X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD) analysis, laser particle size testing, optical microscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and mineral liberation analysis, were employed to elucidate the mineralogical characteristics of the iron concentrate. The analysis revealed that the iron concentrate had a total iron (TFe) grade of 65.56 %, with SiO 2 and Al 2 O 3 contents of 8.28 % and 0.38 %, respectively. Subsequently, a combined beneficiation process involving magnetic separation, flotation, and chemical leaching was conducted. Experimental results showed that a single magnetic separation obtained an iron concentrate grade of 67.52 % with an overall recovery of 86.18 %. Following magnetic separation, flotation was conducted to increase the concentrate grade. With one roughing and four cleaning flotation stages, a concentrate grade of 72.19 % and a 36.36 % overall recovery were achieved. A subsequent leaching operation after flotation yielded high-purity magnetite with a Fe grade of 72.30 % and an overall recovery of 35.68 %. The high-purity magnetite was confirmed to have a purity of up to 99.9 % based on chemical titration, XRD analysis, magnetic susceptibility measurement, and SEM analysis. Furthermore, detailed kinetics studies on leaching were conducted to elucidate the reaction mechanism, revealing an apparent activation energy of 25.70 kJ/mol. The successful implementation of this process will provide a benchmark for producing similar high-purity magnetite concentrates and contribute to China's dual-carbon goals. [ABSTRACT FROM AUTHOR]

Dolomite, a prominent calcium-bearing gangue mineral found in carbonate-type zinc oxide ores, poses a significant challenge for effective flotation separation alongside smithsonite due to their highly similar surface properties. The present study explores the potential of 2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctanoic acid (2-DMPT) as a collector for the reverse flotation of smithsonite from dolomite. Micro-flotation experiments indicated that saponified 2-DMPT exhibited superior collecting ability and selectivity for dolomite over smithsonite under highly alkaline conditions. Specifically, the flotation recovery of dolomite reached 62%, whereas only 6% of smithsonite was recovered in the flotation foam products. Zeta potential and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) analysis revealed that changes in pH values had minimal influence on the collector’s adsorption onto dolomite, while significantly hindering its adsorption on the smithsonite surface. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis showed that 2-DMPT could form hydrophobic complexes with the active Ca2+ sites on the dolomite surface at pH 11.5. However, the interaction between smithsonite and carboxylic groups of 2-DMPT under the same conditions was relatively weaker, facilitating their reverse flotation separation. As a result, 2-DMPT shows promise as a potential collector for the reverse flotation process, effectively removing dolomite from smithsonite and reducing acid consumption in subsequent acid-leaching processes.

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is critical for water quality in flotation as it dramatically influences the chemical/electrochemical properties of mineral surfaces and their interactions with reagents. Many potential variations could alter the water chemistry: water recirculation, mineral dissolutions, reagent additions, etc. This study aimed to identify the key elements from the recycled water sources affecting the separation efficiency in a typical industrial flotation circuit of iron oxides through a series of bench/micro flotation tests, zeta potential measurement, etc. The built-up and distribution of the dominant cations/anions in the process water from the roughers in the flotation system was also analyzed and recorded by Inductively Coupled Plasma-Optical Emission (ICP-OES) for a period of about three months when the operations were stable. The flotation results pointed out that a concentrate with a sharp increase of 6.0% Fe recovery and 2.5% SiO2 content was obtained by using the recycled tailing water only in comparison by using fresh water. In contrast, a slight uptrend in the grade of Fe but a substantial loss of near 6.5% Fe recovery occurs by using the treated sewage water alone instead. This could attribute to the ion distributions in these water sources, in which Ca2+, Fen+, Mg2+ or SO42- ions were determined as the key ions influencing the flotation behaviors of the iron ore. But the competitive effects of Fe3+ ions were more significant than the ones of Ca2+ or Mg2+ ions. And the occurrence of starch could deteriorate the dilution of silicates in concentration induced by Fe3+/Fe2+ ions. It can be explained by zeta potential measurement or solution chemistry of those ions, indicating that at 8.5-9.0, the coating of the precipitates of Fe(OH)3(s) induced by iron ions alters a reverse on the zeta potentials of quartz. The presence of SO42- ions, however, has a positive role in reducing the possibility of slime coating on silicates due to acting as a chelating agent of iron ions. [ABSTRACT FROM AUTHOR]

Recovery and grade are the two crucial performance parameters commonly used in mineral processing plant operations. These two parameters are interdependent. An increase in recovery would result in a decreased product grade and vice versa. The present study enumerates concentration efficiency (CE),which can be adopted exclusively for processing low-grade hematite ore by WHIMS—the reverse flotation route to produce a pellet grade concentrate. In this study, the ore's amenability by wet high-intensity magnetic separation followed by the reverse flotation of a magnetic concentrate route is investigated on BHQ samples of the Sandur schist belt (Kumaraswamy hills), India, after its characterization by microscopic and XRD studies. Dodecyl amine acetate was used as a collector to float siliceous gangue while depressing hematite using the freshly synthesized caustic starch as a depressant. The separation efficiency of the flotation was evaluated by estimating the grade, recovery, and concentration efficiency. The WHIMS conducted using the feed with the particle size minus 106 µm (d80 = 82 µm) followed by reverse flotation produced a pellet grade concentrate assaying 64.60% Fe, a 0.32 alumina-to-silica ratio with 60.4% Fe recovery, and a yield of 37.4% with 79.0% concentration separation efficiency. [ABSTRACT FROM AUTHOR]

Through the single mineral flotation test, the flotation behavior of magnesite and dolomite in the dodecylamine flotation system and the influence of the regulator Fe3+ on the floatability of the two minerals were studied. Based on Fourier Infrared Spectroscopy (FTIR) and contact angle test, the mechanism of Fe3+ was studied. The flotation test results show that in the dodecylamine system, under the natural pH condition of the pulp, the floatability of dolomite is better than that of magnesite. There is a certain floatation difference between magnesite and dolomite, and the addition of a small amount of Fe3+ significantly improves the floatation difference of the two minerals. Infrared spectroscopy test results show that the adsorption of dodecylamine on the surface of dolomite is mainly electrostatic adsorption, dolomite CO32- out-of-plane bending vibration and CO32- in-plane bending vibration are almost unchanged, and -CH3 and -CH2 are symmetrical and asymmetrical. The peak value of extensional vibration increases. The contact angle test results show that the addition of a small amount of Fe3+ enhances the hydrophobicity of dolomite, which has the effect of activating dolomite. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dissolution characteristics of minerals, dissolution of flotation agents in solutions, and equilibrium of dissociations and associations serve as the basis for determining the optimal conditions for the effective components of flotation agents and for evaluating the interaction between flotation agents and minerals. This basis provided the theoretical support for the flotation separation of minerals. Based on this, the flotation separation of magnesite and calcite was realized using sodium dihydrogen phosphate, also known as monosodium phosphate (MSP), as a regulator and dodecylamine (DDA) as a collector. When MSP was used in the DDA system, single-mineral and binary mixed-ore flotation tests revealed that the floatability of calcite was significantly greater than that of magnesite and the separation of magnesite and calcite was more effective, respectively. Zeta potential measurements showed that MSP-containing negative groups could selectively reduce the zeta potential of calcite and promote the adsorption of DDA-containing positive groups on the surface of the calcite. However, this effect was negligible on the zeta potential of magnesite. Due to the stronger affinity of MSP to Ca2+ than that to Mg2+, as demonstrated by Fourier transform infrared and X-ray photoelectron spectroscopy analyses, the MSP was adsorbed onto the surface of calcite primarily by hydrogen bonds rather than magnesite, which promoted the stronger adsorption of DDA-containing positive groups on the surface of the calcite. As a result, the differences in the floatability of magnesite and calcite were enlarged by MSP. Thus, MSP can be utilized an effective regulator for the efficient separation of magnesite from calcite via reverse flotation. [ABSTRACT FROM AUTHOR]

This paper takes the lignite coal sample from Baori Hiller of Inner Mongolia as the research object.Through the coal flotation reverse flotation test and orthogonal test, the surface characteristics and flotation characteristics of lignite were analyzed and studied, and the types, dosages and processes of the lignite flotation were investigated.The results showed that the de-flotation effect of dodecyl amine(DDA)on lignite was better than that of octadecyl amine(ODA)and cetyltrimethylammonium bromide(CTAB).When the DDA dosage is 1 400 g/t, the reverse flotation efficiency is 6.89 %, the floating tail minimum ash is 11.23 %, the floating tail yield is 84.46 %, and the maximum difference between the floating fine and floating tail ash is 5.25 %. When the dosage of DDA is fixed and the dosage of dextrin is 1 600 g/t, the floating ash is divided into 15.58 %, the floating ash is 10.77 %, and the difference is 4.81 %; The effect of the amount of DDA, dextrin and octanol on the yield of floating tail was not significant, while the effect of DDA on floating tail ash was significant, but the effect of dextrin and octanol on floating tail ash was not significant.For lignite, continuous low-floating(10.20 %)and high recovery(up to 70 %)of clean coal can be obtained by successive multiple reverse flotation processes.Amine collectors have a good collection effect on minerals such as quartz, silicate and carbonate in lignite due to their physical adsorption and complex adsorption.In the pulp, the hydrogen atoms in the dextrin interact with a large number of strongly electronegative atoms such as oxygen and nitrogen present on the surface of the lignite to form a strong hydrogen bond, thereby forming a hydrophilic film on the surface of the coal particles, so that the coal particles become hydrophilic and suppressed.

Chlorite is often associated with hematite and tends to form microfine particles during grinding, making it challenging to recover and separate from hematite through flotation. This study innovatively applies an ester-based cationic polyacrylamide (CPAM) as a flocculant in a reverse flotation system using dodecylamine (DDA) as a collector, to flocculate and recover microfine-grained chlorite. The method achieves efficient separation between microfine chlorite and hematite. Laser particle size testing and optical microscopy show that CPAM significantly increases the apparent particle size of microfine chlorite, causing it to aggregate into flocs, while having a extremely weak effect on hematite flocculation. Further analysis using techniques like Zeta potential, contact angle measurement, Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) reveals CPAM's stronger adsorption affinity for chlorite compared to hematite. The ester groups in CPAM selectively form hydrogen bonds with chlorite's surface H atoms, enhancing its hydrophobicity. Particle-bubble attachment angle testing confirms that the flocculated chlorite flocs exhibit better floatability and higher efficiency in collision and adhesion with bubbles. Thus, CPAM serves as an efficient flocculant for reverse flotation separation of microfine chlorite and hematite. [Display omitted] • Flocculation reverse flotation of microfine-grained chlorite and hematite. • Application of CPAM containing ester groups as a novel hydrophobic flocculant. • Selective flocculation of microfine-grained chlorite. • Analyzed the adsorption mechanism of CPAM on the surface of hematite and chlorite. • Visualized the analysis of the wrapping angle between chlorite and bubbles. [ABSTRACT FROM AUTHOR]