Micro-flotation Tests Research Articles

Hydrophilic Modification of Macroscopically Hydrophobic Mineral Talc and Its Specific Application in Flotation.

Sodium diethyldithiocarbamate (DDTC), a common collector used to enhance the hydrophobicity of minerals in froth flotation, nevertheless weakens the hydrophobicity of the talc surface. To rationalize this anomaly, the interactions of a hydrophobic alkyl group and hydrophilic mineralophilic group (-NCS2-) of heteropolar surfactant DDTC, and a water molecule with the talc (001) surface, were investigated. Herein, DFT simulations found that the talc (001) surface features natural hydrophobicity determined by the competition between adhesion (surface water) and cohesion (water-water interactions). The interaction of the hydrophobic alkyl group of DDTC with the talc surface is more favorable compared to that of the -NCS2- group and H2O, favoring the hydrophilic modification of the talc surface. Additionally, adsorption isotherms, time-of-flight secondary ion mass spectrometry (ToF-SIMS), microflotation tests, and contact angle measurements also indicate that the differences in adsorption orientation of the heteropolar surfactant DDTC on the talc surface enhance the hydrophilicity of the talc surface, leading to a decreased recovery of the talc. This study provides crucial surface chemistry evidence for the selective adsorption of heteropolar surfactants and contributes to the understanding of the mechanism for the efficient flotation separation of molybdenite from talc.

Flotation performance and adsorption mechanism of monazite after the transformation of hydrogen-based mineral phase by octyl hydroxamic acid

This study investigated the laws affecting flotation properties of monazite minerals after roasting pretreatment. The flotation performance and adsorption mechanism of monazite after roasting were investigated systematically through simulation tests, which included micro-flotation tests, Brunauer–Emmett–Teller (BET) analysis, contact angle measurement, zeta potential analysis, scanning electron microscopy energy dispersive spectroscopy, Fourier transform infrared analysis, X-ray photoelectron spectroscopy, and DFTB+. The results of the microflotation tests indicated that octyl hydroxamic acid (OHA) had a superior recovery effect on monazite at a pH of ∼9. The flotation performance of OHA on monazite was significantly better than those of salicylhydroxamic acid (SHA) and benzohydroxamic acid (BHA) under the same conditions. A molecular model of monazite after roasting was simulated and structurally optimized using DFTB+. The adsorption energies were calculated for SHA, BHA, and OHA, which confirmed the strong and stable adsorption of OHA on the surface of monazite after roasting.

Enhancement of KCl flotation through crystallization regulation during carnallite decomposition

Particle size and surface morphology have a substantial influence on flotation. Conventional grinding methods usually destroy the surface morphology while controlling the particle size. In this work, we propose a new strategy to control particle size and morphology through crystalizing regulation instead of grinding to protect the crystal face in the flotation process. Scanning electron microscopy results illustrate that the surface morphology of crystallization-regulated particles is better protected than grinding-regulated particles. The superior flotation effect of the crystallization-regulated products was validated by micro-flotation tests. The mechanism of enhanced flotation by crystalline modulation was further analyzed with the help of induction time, adhesion-desorption force, collector adsorption, and theoretical calculations, which showed that the crystallization-regulated products were more hydrophobic and had more stable adherence to the flotation bubbles. The innovative method of crystalline modulation developed in this work to improve the flotation effect provides a novel way to protect the crystal shape for the efficient flotation of potash salts, which is of great significance for the reduction of cost and increase of efficiency in the flotation process of potash salts.

Application and electrochemical depression mechanism of sodium sulfite on the flotation separation of galena–pyrite mixed concentrate in Yiliang typical high‑sulfur lead–zinc deposit

The high content of pyrite in high‑sulfur lead–zinc sulfide resources affects the electrochemical properties and floatability of galena and sphalerite, which results in difficult flotation separation. In this study, the negative effects of a high-alkaline process were weakened by introducing an efficient mixed depressant CaO + Na2SO3 in selective flotation separation of galena from pyrite. Flotation separation tests of real ore samples showed that the mixed depressant was more efficient than single CaO (5000 g/t), and the best process conditions of Pb grade 64.01 % and Pb recovery 88.45 % were obtained. The effects of Na2SO3 on the electrochemical interaction between the two minerals were studied by micro-flotation tests, electrochemical, ion dissolution, UV–Vis measurements, zeta potential measurements, and X-ray photoelectron spectroscopy (XPS) detections. Results indicated that Na2SO3 could weaken the galvanic interaction between galena–pyrite and reduce the Pb2+ dissolution from the galena surface. Na2SO3 could desorb the collector ethyl xanthate pre-adsorbed on the pyrite surface.

Insight into the effect of ultrasonic treatment on surface properties and flotation behavior of chalcopyrite after galvanic corrosion of grinding media and chalcopyrite

Ultrasonic treatment is an effective means to promote chalcopyrite flotation. Chalcopyrite needs to be grinded before flotation production. During the grinding process, galvanic corrosion occurs between chalcopyrite and iron grinding media. Galvanic corrosion significantly affects the efficacy of ultrasonic treatment on chalcopyrite flotation. Nonetheless, there is still a lack of research on ultrasonic treatment of chalcopyrite after galvanic corrosion. In this study, micro-flotation tests, SEM-EDS, TOF-SIMS, XPS, ICP-OES and electrochemical tests were used to study the effects of ultrasonic treatment on the surface properties and flotation behavior of chalcopyrite before and after galvanic corrosion under different ultrasonic conditions and galvanic corrosion conditions. The results show that in the absence of galvanic corrosion, short time and low power ultrasonic treatment can improve chalcopyrite floatability. However, when the chalcopyrite after strong galvanic corrosion is subjected to ultrasonic treatment, the increase of galvanic corrosion temperature, galvanic corrosion time, ultrasound power and ultrasound time result in a marked reduction of the flotation recovery of chalcopyrite. The synergistic effect of ultrasonic and galvanic corrosion significantly inhibits the flotation recovery of chalcopyrite, which may provide a new potential way for the inhibition of sulfide ore in flotation production. The research results are helpful to expand the use range of ultrasonic processing for sulfide mineral pretreatment and flotation, and provide a theoretical reference for the application of ultrasonic treatment in sulfide minerals with galvanic corrosion.

Application of a novel auxiliary collector for molybdenite fines recovery in sustainable froth flotation production: Combining DFT calculations and experiments

The recovery of molybdenite diminishes with a reduction in particle size, which causes serious resource waste and financial loss. In this work, 1-dodecanethiol (NDM) was explored as an auxiliary collector to enhance the flotation of molybdenite fines. The flotation performance and adsorption mechanisms were revealed by micro-flotation tests, Zeta potential, contact angle, X-ray Photoelectron Spectroscopy (XPS), and density functional theory (DFT) calculations. Economic and environmental risks were assessed by industrial-scale flotation tests. The micro-flotation tests showed that NDM was more effective in improving the recovery of the −20 μm grade compared to the −38+20 μm grade. Zeta potential and contact angle results indicated that NDM significantly enhanced the hydrophobicity of the finer-grained molybdenite surface. XPS and DFT calculations revealed that water molecules acted as a significant barrier to kerosene adsorption, and NDM overcame this limitation by selectively adsorbing on the edge of molybdenite. The economic and environmental assessment indicated that NDM increased monthly product profits by $319,283.38 and was environmentally friendly, which can be extensively employed for mineral sources with similar mineralogical properties.

Synergistic adsorption mechanism of novel combined collector in flotation separation of fayalite from magnetite: Experiments and MD simulations

As an iron-bearing silicate mineral, fayalite has similar surface properties to magnetite, which makes it challenging to efficiently separate fayalite from magnetite by flotation. In this study, magnetite and fayalite were separated using novel combined collector polyoxyethylene alkyl amine (PAE) and terpinol (AT) through reverse flotation. Combined with a variety of characterization analysis and molecular dynamics (MD) simulation, the synergistic adsorption mechanism of the combined collector on mineral surface was revealed from multiple perspectives. The optimum scheme and pH response range of the combined collector were determined by micro-flotation test. Compared with PAE alone, the difference value of flotation recovery between fayalite and magnetite using combined collector was increased by 10.16%, and the dosage was reduced by 20%. Additionally, an effectively adsorption of combined collector onto fayalite surface to improve its surface hydrophobicity. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and MD simulations results showed synergistic adsorption was produced onto fayalite surface using combined collector mainly through non-polar interaction, hydrogen bond association and bridge adsorption. Furthermore, the spatial distribution and diffusion behavior of water molecules provide microscopic evidence for the enhancement of surface hydrophobicity of fayalite by combined collector.

Soluble mineral flotation paradox: Improved recovery with no sign of collector adsorption on minerals signifies colloidal attraction between bubble-bound collector colloids and mineral particles

Froth flotation uses air bubbles to separate mineral particles based on the difference in mineral surface hydrophobicity. Collectors are needed to selectively hydrophobize the surface of targeted minerals to augment the difference in surface hydrophobicity between wanted minerals and unwanted ones. Here, we showed that this classical (well-established) principle fails to describe the flotation of water-soluble minerals. Our systematic micro-flotation tests using soluble minerals (NaCl and KCl crystals) in brines and three popular collectors (dodecylamine hydrochloride, sodium dodecylsulfate, and sodium laurate) showed a substantial flotation recovery of the salt minerals without detected collector adsorption at the mineral surfaces by X-ray photoelectron spectroscopy (XPS). Complementary particle size distribution measurement indicated the occurrence of sub-micron collector colloids in saturated brines. Moreover, the flotation recovery agreed well with the measured contact angle, suggesting the attraction between bubble-bound collector colloids and salt crystal surfaces. These paradoxical results signify a new principle underlying the flotation of soluble minerals, i.e., the selective colloidal attraction between bubble-bound collector colloids and salt particles enables the flotation separation of soluble minerals.

The selective flotation separation of apatite from dolomite using carrageenan as an innovative bio-based inhibitor

The direct flotation is highly effective in enhancing the quality of concentrate products and removing the content of magnesium for the beneficiation of middle and low grade phosphate ore. This study introduces carrageenan (CG) as an innovative dolomite inhibitor and assesses its effectiveness through micro-flotation tests with sodium oleate (NaOL) as a collector. At pH 10, the combination of 40 mg/L CG and 4 × 10−4 M NaOL successfully separated dolomite from apatite, the artificially mixed ore tests produced a concentrate assaying 32.23 % P2O5 with 76.44 % P2O5 recovery. Results demonstrate CG's strong inhibition of dolomite while minimally affecting apatite. The interaction mechanisms of CG with apatite and dolomite were investigated through various analyses including ICP-OES tests, zeta potential measurements, FTIR tests, contact angle measurements, XPS analysis, AFM tests, and ToF-SIMS analysis. Findings suggest that CG adsorbs strongly to dolomite surfaces by chemisorption between carboxyl groups and Ca sites, whereas it adsorbs weakly to apatite surfaces by hydrogen bonds between carboxyl and hydroxyl groups with F sites. Thus, CG shows promise as an innovative bio-based inhibitor for separating apatite from dolomite using direct flotation.

Enhancement mechanism study on the fine hematite flotation by hydrophobic glass microspheres

Previous studies have primarily focused on the use of coarse mineral particles or hydrophobic materials as carriers, whereas this study was the first to investigate the impact of different hydrophobic glass microspheres (HGM-butane, HGM-pentane and HGM-octane) on the flotation behavior of fine hematite, and it revealed the interaction mechanism through Zeta potential and flotation kinetics analysis. The results of micro-flotation tests indicated that the addition of HGM-pentane can increase the flotation recovery of fine hematite from 65.27 % to 84.64 %, which was significantly better than using the collector NaOL alone. Zeta potential results showed that the incorporation of HGM-pentane caused a further negative shift in the surface potential of hematite, enhancing its adsorption capacity with bubbles. Flotation kinetics analysis demonstrated that the addition of HGM-pentane increased the flotation kinetic constant, promoting the flotation rate of fine hematite. This study revealed that the interaction between hydrophobic glass microspheres and fine hematite was primarily through hydrophobic forces and electrostatic attraction, forming a hematite-HGM complex, which in turn improved the flotation recovery of fine hematite. This provided a theoretical basis for the development of efficient flotation reagents and offers new insights into the efficient utilization of fine hematite.

Study on flotation behavior and mechanism of galena flotation separation from chalcopyrite by sodium periodate depressant

The successful separating galena and chalcopyrite by flotation presents difficulties owing to their analogous surface chemical properties. This study investigated sodium periodate (SP) as a novel depressant for selectively oxidizing and modifying chalcopyrite and galena surfaces, enabling successful flotation separation. In micro-flotation tests were carried out at pH 8.5 and SP concentration of 5 × 10−4 mol/L. The grades of Cu and Pb in the copper concentrate were 27.87 % and 23.13 % with recoveries of 81.22 % and 27.78 %, respectively. SP selectively inhibited galena floatability while preserving chalcopyrite floatability. The selective depression mechanism research of SP in flotation separation process showed that galena surface hydrophobicity was significantly reduced by SP, which in turn prevented the collecting agent from adhering to galena. In the presence of SP, hydrophilic species such as PbSO4 and Pb(OH)2 were generated on the surface of galena, which decreased its ability to float. Conversely, on the chalcopyrite surface, hydrophobic products such as CuS2, CuSn, and S0 were formed, having little effect on its floatability. A model was developed to elucidate the mechanism underlying the selective flotation separation of the chalcopyrite and galena using SP.

Enhanced marmatite activation by copper with ammonium sulfate: An experimental and DFT investigation

The presence of iron atoms on the marmatite surface hinders effective interaction between the activator and the mineral, leading to unsatisfactory flotation performance through direct copper (Cu) activation. Hence, this study introduced ammonium sulfate to enhance the marmatite-activation capability by Cu ions. Additionally, the reinforcement mechanism was investigated through microflotation tests, atomic force microscopy (AFM), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and density-functional theory (DFT) calculations. Microflotation results demonstrated that the addition of ammonium sulfate as a complexing reagent increased the flotation recovery of marmatite by 17.36%. AFM analysis revealed that marmatite subjected to enhanced activation (i.e., in the presence of ammonium sulfate) exhibited a considerably higher surface roughness than that subjected to direct Cu activation. Moreover, the average height of hill-shaped materials on the marmatite surface notably increased to 9.6 nm after enhanced Cu activation. SEM-EDS analysis revealed that the concentration of Cu atoms (2.2%) on the marmatite surface after enhanced Cu activation was nearly three times that (0.8%) after direct Cu activation. Additionally, XPS results indicated a considerably higher presence of the Cu–S component on the marmatite surface after enhanced Cu activation than after direct Cu activation. ToF-SIMS analysis indicated an increase in the fragment peaks of Cu+, CuOCS2+, OCS2−, and OC2H2S2− on the surface of enhanced-activated marmatite. Additionally, DFT calculations indicated that the presence of NH3 molecules enhanced electron transfer between Cu and S on the hydrated marmatite surface. The marmatite (1 1 0) surface exhibited more negative adsorption energy of Cu ions after the action of NH3 molecules, and NH3–Cu showed a more stable adsorption configuration than Cu. Therefore, the addition of ammonium sulfate enhanced the Cu activation for marmatite, thereby improving flotation performance.

Investigation into the impact of Mn2+ and its interaction with calcite in the flotation of rhodochrosite

The unavoidable Mn2+ ions in pulp were considered in the flotation of rhodochrosite, and its effect and relative interaction mechanism on the floatability of calcite served as a typical gangue mineral were investigated through microflotation tests, zeta potential measurements, SEM-EDS detection, solution chemistry calculation, adsorption experiments, FTIR and XPS analyses. There exhibited a good separation performance of rhodochrosite against calcite with OHA collector, but in the presence of Mn2+ ions, the floatability of calcite was closed to rhodochrosite within a pH of 8.0–10.0, which resulted in the separation difficulty between them. As evidenced, the surface of calcite could be modified by Mn2+ ions, its isoelectric point shifted positively from 8.91 to 10.06, and Mn2+ species detected on calcite surfaces were in close proximity to rhodochrosite. It indicated that MnCO3 precipitates were generated on the surface of calcite. After modified by Mn2+, the calcite surface became more active and obviously increased the adsorption amount of OHA. It was verified from zeta potential and XPS analyses that Mn species on the surface of calcite were active sites for OHA adsorption, likely the hydroxamate group of OHA collector chelated with Mn species to form hydrophobic compounds. As a result, Mn2+ ions in pulp would reduce the flotation selectivity of rhodochrosite from calcite, thus it is necessary to eliminate the disadvantage of Mn2+ for strengthening flotation.

Effect of Pre-Sulfidization on the Octadecyl Amine Adsorption on the Smithsonite Surface and Its Flotation.

The low-grade zinc oxide ore was sulfidized to increase the efficiency of flotation, but the effect of pre-sulfidization on the adsorption mechanism of octadecyl amine (ODA) on the smithsonite surface is currently unclear. In this study, the effect of pre-sulfidization on the adsorption mechanism of ODA and the flotation behavior was studied using smithsonite and pre-sulfidized smithsonite as the samples by zeta potential, contact angle measurement, total organic carbon analyzer (TOC), quartz microcrystalline balance (QCM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and micro-flotation tests. Micro-flotation tests showed that the pretreatment of sulfidization could improve the floatability of smithsonite. Zeta potential and contact angle measurements demonstrated that pre-sulfidization could favor the adsorption of ODA, which is further confirmed by the adsorption tests of ODA using TOC and QCM. Furthermore, FTIR and XPS analysis showed that pre-sulfidization changes the adsorption mode of ODA, changing it from physical adsorption to chemical adsorption. These results suggested that the favorable effect of pre-sulfidization on the adsorption of ODA and the flotation of smithsonite might provide important guidance for industrial application.

Utilization of Lead Nitrate to Enhance the Impact of Hydroxamic Acids on the Hydrophobic Aggregation and Flotation Behavior of Cassiterite.

Lead nitrate (LN) is frequently employed as an activator in the flotation of cassiterite using hydroxamic acids as the collectors. This study investigated the effect of LN on the hydrophobic aggregation of cassiterite when benzohydroxamic acid (BHA), hexyl hydroxamate (HHA), and octyl hydroxamate (OHA) were used as the collectors through micro-flotation, focused beam reflectance measurement (FBRM) and a particle video microscope (PVM), zeta potential, and the extended DLVO theory. Micro-flotation tests confirmed that LN activated the flotation of cassiterite using the hydroxamic acids as collectors. Focused beam reflectance measurement (FBRM) and a particle video microscope (PVM) were used to capture in situ data on the changes in size distribution and morphology of cassiterite aggregates during stirring. The FBRM and PVM image results indicated that the addition of LN could promote the formation of hydrophobic aggregates of fine cassiterite, when BHA or HHA was used as the collector, and reduce the dosage of OHA needed to induce the formation of hydrophobic aggregates of cassiterite. The extended DLVO theory interaction energies indicated that the presence of LN could decrease the electrostatic interaction energies (Vedl) and increase the hydrophobic interaction energies (Vhy) between cassiterite particles, resulting in the disappearance of the high energy barriers that existed between the particles in the absence of LN. Thus, cassiterite particles could aggregate in the presence of LN when BHA, HHA, or a low concentration of OHA was used as the collector.

COMPARATIVE ANALYSIS OF FLOTATION EFFICIENCIES BETWEEN MICROFLOTATION CELL AND BATCH FLOTATION CELL TESTS

One of the most important methods in the beneficiation of sulfide ores is flotation. Flotation experiments on a laboratory scale are mainly carried out through batch flotation and microflotation tests. In this study, comparative flotation experiments of pyrite minerals were conducted under the same conditions using the two methods mentioned above. A series of experiments were carried out with different pH values and collector dosages selected as flotation parameters. The highest flotation recovery was obtained at a pH of 7.5 with the use of PAX. Furthermore, within the conditions studied, a correlation of 94% was found between the two flotation techniques when using PAX, while it was 98% in the use of PEX. In this study. It was shown that the microflotation method can be used to estimate the efficiency values that can be obtained with batch flotation experiments.

Flotation separation of hematite from quartz with dodecyl trimethyl ammonium chloride and sodium dodecyl sulfonate collector

Through a series of testing methods, including micro-flotation tests, contact angle test, ζ-potential analysis, FTIR, and XPS, the behavior and mechanism of flotation separation of hematite and quartz by mixed anionic-cationic collectors (Dodecyl Trimethyl Ammonium Chloride (DTAC) and Sodium Dodecyl Sulfonate (SDS), DS for short) were investigated. Additionally, the froth performance of the mixed collector was examined through froth stability experiments. The study revealed that the inclusion of DS collectors significantly enhanced the flotation separation efficiency of quartz-hematite, with the addition of SDS leading to a reduction in the foam viscosity of DTAC. Notably, at a pH of 7 and with a DTAC to SDS mass ratio of 2:1, the mixed collector demonstrated exceptional performance in the flotation separation of quartz and hematite, achieving a quartz recovery of 91.85 % and a hematite recovery of 11.45 %. This efficacy was corroborated by ζ-potential measurements, FT-IR analysis, and XPS analysis, which confirmed the physical adsorption of DS on the mineral surfaces. Importantly, the adsorption dynamics were found to be influenced by the different surface charge characteristics of quartz and hematite. Specifically, the higher negative charge on the surface of quartz resulted in unaffected DTAC adsorption in the presence of SDS, while on hematite surfaces, the DTAC interaction with SDS led to the partial desorption of DTAC. Consequently, the adsorption of DTAC on hematite surfaces was reduced, facilitating the selective separation of quartz and hematite.

Effect of lead ions treatment on the flotation behavior of lime-depressed pyrite in a butyl xanthate system

Pyrite is often found alongside other sulfide minerals and is typically suppressed by lime during industrial flotation to selectively enrich with other valuable minerals. Given the continuous depletion of mineral resources, recycling these suppressed resources has become necessary. Consequently, the reactivation of lime-depressed pyrite is crucial for its recovery via flotation. This study investigated the lead (Pb) nitrate to activate lime-depressed pyrite. Various analytical techniques, including micro-flotation tests, zeta potential measurements, contact angle measurements, ultraviolet–visible spectrophotometry, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM-EDS) were employed to investigate the activation mechanism of Pb2+ on lime-depressed pyrite. The treatment with Pb2+ resulted in a significant enhancement in the recovery of lime-depressed pyrite flotation, achieving a maximum recovery of 98.33 %. Analysis through zeta potential, XPS, and SEM-EDS revealed that Pb species reacted with lime-depressed pyrite surfaces to form Pb-S and Fe-O-Pb species. This reaction enhanced the active sites and adsorption of collectors on lime-depressed surfaces, consequently increasing the hydrophobicity of the pyrite particles.

Selective adsorption mechanism of polyoxyethylene alkyl amine in reverse flotation separation of fayalite and magnetite without depressant

Effective flotation separation of magnetite from iron-bearing silicate minerals is difficult with conventional collectors because of their similar surface properties. In this work, polyoxyethylene alkyl amine (PAE), which is easy to prepare and has high surface activity, was used for the reverse flotation separation of fayalite and magnetite for the first time, and its selective adsorption mechanism was revealed. The micro-flotation tests results show that compared with dodecylamine (DDA), the separation effect of PAE on fayalite and magnetite was significantly improved. When pH was 6.5 and PAE dosage was 20 mg/L, the selective separation of fayalite and magnetite can be achieved by reverse flotation without depressant. The results of zeta potential and contact angle measurement shown that PAE was significantly adsorbed on fayalite compared with magnetite, so the hydrophobicity of fayalite treated by PAE was effectively enhanced. In addition, the differential adsorption of PAE on fayalite and magnetite was further verified by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulation, where PAE was adsorbed on the surface of fayalite by electrostatic adsorption and hydrogen bonding, while electrostatic repulsion caused PAE to be removed from the surface of magnetite. The angle between the ethylene oxide chains of PAE at adsorption equilibrium reflects the stress state of NH+ and –OH. Therefore, the selective flotation separation of magnetite and fayalite was realized based on the electrical difference of mineral surface and PAE structural characteristics.

Study on expanding flotation performance differentiation of quartz and magnesite by amino-trimethylphosphonic acid in dodecylamine system

In this paper, amino trimethylene phosphonic acid (ATMP) was introduced into the separation process of magnesite and quartz, in order to reduce the content of associated minerals in magnesite and improve the industrial utilization value of magnesite. Micro-flotation tests showed that under the system of dodecylamine as collector, ATMP can selectively depress magnesite within the alkaline pulp environment. When the dosage of ATMP was 100 mg/L and the pulp pH was 11, the flotation recovery of magnesite was 12.65 % and that of quartz was 91.00 %. Additionally, the findings of the artificial mixed mineral flotation showed that a concentrate with a grade of 43.53 % MgO and a recovery of 91.03 % was achieved. Zeta potential, FTIR and XPS analyses demonstrated that ATMP chelated with the active site Mg2+ on the surface of magnesite through –PO3 group. In addition, DFT calculation indicated that the adsorbed ATMP increased the distance of N atom in dodecylamine (DDA) to the surface of magnesite from 2.671 Å to 5.106 Å. The interaction energy between DDA and magnesite increased from −201.28 kJ/mol to −136.75 kJ/mol, resulting in it difficult for DDA to adsorb on the magnesite surface. However, ATMP was difficult to adsorb on the quartz surface and had no effect on the interaction between DDA and quartz. Therefore, the selective depression effect of ATMP on magnesite was realized.