Promoting sulfidation of smithsonite by zinc sulfide species increase with addition of ammonium chloride and its effect on flotation performance

Wu D., Ma W., Wen S., Deng J., Bai S.

Sodium sulfosalicylate was used for the first time to enhance the sulfidation–flotation of smithsonite. Sodium sulfosalicylate could facilitate the flotation of smithsonite, and increase the flotation recovery by ∼28%. Inductively coupled plasma analysis indicated that the surface dissolution of the enhanced sulfurized smithsonite decreased significantly. X-ray photoelectron spectral analysis revealed that smithsonite can be sulfurized easily by using sodium sulfide with sodium sulfosalicylate. The effect of sodium sulfosalicylate on zinc-oxide ore flotation has been verified. Compared with the direct sulfidation–flotation of zinc-oxide ore, enhanced sulfidation–flotation can improve the concentrate grade by 3.83% and the concentrate recovery by 7.63%. Therefore, the addition of sodium sulfosalicylate played a significant role in smithsonite sulfidation, which improves the flotation performance.

Deng R., Zuo W., Ku J., Yang Z., Hu Y.

A cationic organic silicone surfactant (DTA) with specially designed functional groups was developed as a flotation collector for smithsonite. This surfactant was synthesized via the reaction between hexaethyldisiloxane and N -β-(aminoethyl)-γ-aminoisobutylmethyldimethoxy silane using tetramethylammonium hydroxide as a catalyst. Its flotation performance was validated by flotation tests using pure minerals. The results illustrated that DTA has strong collecting ability and better selectivity for smithsonite against quartz, calcite and dolomite compared to the traditional collectors such as octadecylamine, tetradecylamine and dodecylamine. Based on the analysis of FTIR spectra, zeta-potential measurements, X-ray photoelectron spectroscopy and density functional theory calculations, it can be concluded that the adsorption mechanism of DTA on the surface of smithsonite was mainly dominated by chemisorption and electrostatic adsorption. DTA's unique properties, which include two coordination sites ( NH 2 and NH ), and the “parachute” shape structure of OSi(C 2 H 5 ) 3 , resulted in superior collecting powers for smithsonite.

Wu D., Ma W., Wen S., Bai S., Deng J., Yin Q.

Sulfidation-flotation is commonly performed to recover base metal oxide ores. Sulfidation could become the key process in recovering zinc from zinc oxide ores. We investigated the common zinc oxide mineral. An ammonium salt was used to enhance sulfidation-flotation of smithsonite. The effect of ammonium ions on sulfidation and flotation of smithsonite was investigated by microflotation, inductively coupled plasma analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. Addition of the ammonium salt facilitates flotation of smithsonite and improves the flotation recovery by ∼25%. Solubility tests under different conditions indicate that the surface solubility of smithsonite in the presence of ammonium ions significantly decreases. Energy-dispersive X-ray spectroscopy based semi-quantitative analysis shows that the concentration of sulfur on the ammonium enhanced sulfurized smithsonite surface is 8.55%, whereas that on the sulfurized smithsonite surface is 2%. XPS analysis reveals that smithsonite is more easily sulfurized by sodium sulfide in the presence of ammonium ions. Therefore, ammonium ion addition can be used to enhance sulfidation of smithsonite and improve the flotation performance.

Feng Q., Wen S.

The interaction between sulfide-ion species and smithsonite surfaces and its response to flotation performance were investigated by means of microflotation experiments, surface-adsorption tests, zeta-potential determination, and X-ray photoelectron spectroscopy (XPS) analysis. The microflotation experiments results indicated that addition of Na2S elicited a positive effect on the smithsonite floatability within an appropriate concentration range (

Zhang X., Hu Y., Sun W., Xu L.

Khaleghi B., Noaparast M., Shafaei S.Z., Bayat S., Aghazadeh S., Amini A.

A representative sample of zinc oxide from Dashteh Sefid mine was obtained and then mineral characterization studies were done. The results of mineralogical analysis showed that the main zinc-bearing minerals are smithsonite, hemimorphite and gangue minerals are quartz and dolomite. In the present paper, the effect of important factors including sodium sulfide, collector type (AC and AC/KAX), collector amount, sodium silicate, CMC dosage and frother type (MIBC and pine oil) were investigated. Design of experiment was carried out by the means of Design Expert 7 using Fractional Factorial 26–1. The results indicated that collector type, collector amount, CMC and frother dosage were the most effective factors controlling the zinc flotation recovery. For the zinc grade, it was found that all six parameters play a significant role. The maximum recovery and grade of zinc obtained 97.71% and 10.39% under the following optimum conditions: sodium sulfide, 5935.23 g/t; collector type, AC/KAX; collector amount, 654.09; sodium silicate, 300; CMC dosage, 600; frother type, MIBC. The result of two-stage cleaner flotation showed that zinc grade could be increased up to 16.2% with zinc recovery of 61.39%.

Liu C., Feng Q., Zhang G., Ma W., Meng Q., Chen Y.

The effects of Pb(II) ions on the flotation of hemimorphite was investigated by micro-flotation tests, zeta-potential measurements, solution chemistry and Fourier transform infrared spectroscopy. The micro-flotation results indicated that the Pb(II) effectively improved the flotation of hemimorphite minerals. Good floatability of minerals was obtained in the pH region 7 to 9. Adsorption/precipitation of the hydrolyzed species of lead cations occurred in this pH region, these species promote sodium oleate adsorption and from lead oleate on the surface of hemimorphite.

Feng Q., Wen S., Zhao W., Deng J., Xian Y.

The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na 2 S, and the increase in the Na 2 S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na 2 S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na 2 S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite.

Wu D., Wen S., Deng J., Liu J., Mao Y.

Zinc extraction from low-grade mineral resources of oxidized zinc has recently become a focus of study. Sulfidation is an important process in oxidized ore flotation. In this study, the influence of sulfur ion adsorption on smithsonite surface was investigated with the use of zeta potential, inductively coupled plasma (ICP), scanning electron microscope (SEM), and X-ray photoelectron spectroscopic studies. Zeta potential measurements of sodium sulfide showed that sulfur ions were adsorbed onto the surface of pure smithsonite, as evidenced by the increased negative charge and the decrease in the pH IEP of smithsonite from 7.7 to 6 after sodium sulfide treatment. The ICP test revealed the gradual reduction in sulfur ion adsorption onto the surface of smithsonite in pulp sulfur. After 30 min of absorption, C S in the solution declined from 1000 × 10 −6  mol/L to 1.4 × 10 −6  mol/L. SEM results showed that the mineral surface was partially changed to ZnS film after sodium sulfide treatment, whereas EDS analysis results showed that 2% S is contained on the smithsonite surface. X-ray photoelectron spectroscopy results indicated the presence of a characteristic signal peak of sulfur ions after sulfidation. Sulfur concentration increased to 11.89%, whereas oxygen concentration decreased from 42.31% to 13.74%. Sulfur ions were not only present during chemical adsorption, but were also incorporated into the crystal lattices of minerals by the exchange reaction between S 2− and CO 3 2− ions.

Ejtemaei M., Gharabaghi M., Irannajad M.

In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy.

Mehdilo A., Irannajad M., Zarei H.

Shi Q., Zhang G., Feng Q., Deng H.

Both smithsonite and calcite are calcite-group minerals which are isomorphous with one another. They are similar in many physical and chemical properties, and may partially or fully replace one another, which make the separation of smithsonite from calcite inefficient and ineffective in flotation. The present study was undertaken to investigate the solubility properties of individual calcite and smithsonite minerals and their mixtures, and establish correlation between solution chemistry and flotation behavior. Solution chemical calculations show that the species distribution of smithsonite and calcite was strongly affected by solution pH value. With the increase of pH, the measured solubility of calcite is very close to the theoretical value, while that of smithsonite is less than the theoretical value, illustrating that surface precipitations of zinc hydroxide and hydrozincite are possible. In the mixed system, solution chemical calculations show that the conversion from smithsonite and calcite to hydrozincite and zinc hydroxide is spontaneous. The flotation behavior of smithsonite and calcite was studied with the supernatants, and XPS analysis was conducted to detect surface properties. Both simulation results and experimental data show that surface conversion from calcite to zinc species has a vital influence on the separation of smithsonite from calcite by flotation.

Mehdilo A., Zarei H., Irannajad M., Arjmandfar H.

The flotation of smithsonite from tailing which comes from the cerussite flotation circuit was investigated using Armac C and Armac T as amine collectors. The results indicated that the dosage of sodium sulfide, collector type, and desliming are the main affecting factors on the Zn grade and recovery of smithsonite flotation concentrate. Armac T acts a little more selectively than Armac C, and enhances the Zn grade of the concentrate, while Armac C improves the recovery of Zn. At the mixture ratio of Armac C:Armac T = 1:6, without consumption of any gangue depressants, an optimal concentrate with 94.4% recovery, and 42.3% Zn grade is obtained. In this condition, the collectors’ consumption is decreased significantly. Desliming prior to flotation is essential for successful recovery of smithsonite.

Shi Q., Feng Q., Zhang G., Deng H.

The effect of the smithsonite/water interface properties on the floatability of the mineral without and in the presence of sodium carbonate was examined through zeta potential measurements, microflotation tests, and the concentration of Zn2+ ions measurement, in the pH range from 7 to 11. The isoelectric point value of the mineral was achieved at pH 8.0, and the species Zn2+, OH−, HCO3−, CO32−, and H+, as well as the reabsorption of hydrolysis products would determine the smithsonite–solution interface properties. Smithsonite presents high floatability with sodium oleate (1.5 × 10−4 mol/L) between pH 7.0 and 8.0. Above pH 8.0, the smithsonite floatability decreases abruptly, and the polymeric zero-charged Zn(II) hydrolyzed species [ Zn ( OH ) 2 ( H 2 O ) 2 ] n 0 is proposed for depressing the floatability of smithsonite. With the sodium carbonate added into the solution, the isoelectric point value of the mineral was achieved at pH 8.2. The smithsonite interface, having more surface cation sites and zinc species in the Stern layer, gives rise to the floatability in the pH range from 7.0 to 8.7. Due to the formation of Zn(CO3)22−, the decrease of the concentration of the hydrolyzed species [ Zn ( OH ) 2 ( H 2 O ) 2 ] n 0 makes smithsonite more floatable than that without the Na2CO3 at 8.7

Sun W., Su J., Zhang G., Hu Y.

A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10−4 % Ag (mass fraction) from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb2+ and has a sulfidation on oxidized lead minerals. The results also show that Na2CO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.

Yang W., Tang Y., Han G., Miao Y., Zhao W., Feng Q.

Khalil A., Ait-khouia Y., Beniddar H., El Ghorfi M., Hakkou R., Taha Y., Benzaazoua M.

Li R., Shao Y., Li J., Liu C., Chen H., Meng X., Jia X.

The increasing demand for zinc resources and the declining availability of sulfide zinc ore reserves have made the efficient utilization of zinc oxide a topic of considerable interest. In this study, a ternary composite collector ABN (Al-BHA-NaOL system) was applied to the direct flotation of smithsonite. Micro-flotation studies showed that at pH 9, ABN exhibited better adsorption on smithsonite, achieving a recovery rate of 80.62%. Visual MINTEQ 3.1 and zeta potential analysis confirmed that ABN predominantly reacted with Zn(OH)2(aq) on the surface of smithsonite. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis results elucidated the formation of Al-O bonds through chemical adsorption on the smithsonite surface. Additionally, powder contact angle measurements indicated that ABN enhances the surface contact angle of smithsonite. These results illuminate that ABN is adsorbed by reacting with O sites on hydroxylated metal ions on the smithsonite surface, with Al serving as the adsorption center, thereby achieving separation and purification. Due to ABN’s adsorption characteristics, smithsonite can achieve efficient and clean direct flotation recovery without sulfidization.

Luo Y., Sun W., He S., Peng J., Jiang F.

Chen H., Zuo Q., Wu D., Wu F., Kong N., Cao J.

Li B., Zhang G., Shi Q.

Zhang S., Liang G., Xian Y., Wen S.

Triethanolamine (TEA) is a promising eco-friendly alternative to inorganic ammonia for enhancing surface sulfidization and flotation recovery of smithsonite. Micro-flotation experiments revealed an enhancement in smithsonite recovery to 95.21% with TEA modification, comparable to the results obtained using ammonia. The mechanisms behind the ability of TEA to enhance the sulfidization process were investigated through surface analysis and molecular dynamics simulations. TEA modification increased the content of sulfidization products, the proportion of crucial S22− in adsorbed products, and the thickness and size of the sulfidization product layer. The complexation of TEA with Zn sites formed positively charged Zn–TEA complexes that adsorb onto the smithsonite surface. These complexes promoted negatively charged HS− adsorption, creating a multi-layered adsorption structure. Moreover, TEA modification reduced the total energy required for the sulfidization. These findings open up new possibilities for using eco-friendly reagents in mineral processing, highlighting the potential of TEA in green mineral processing practices.

Jia K., Jin Y., Liu S., Qin W., Zhang C., Li G., Cao Y.

Utilizing an efficient activator is an efficient solution to overcome the low recovery flotation of zinc oxide ore. We proposed amino acids as new high-efficiency biological activators for zinc oxide ore flotation and systematically studied the effects of amino acids as activators in the flotation of zinc oxide ore. Fourier transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and density functional theory (DFT) calculations were conducted to reveal the activation mechanism of amino acids in smithsonite flotation. The results showed that tryptophan (Trp) significantly promoted the floatability of smithsonite by coordinating with zinc sites on the surface of smithsonite. The addition of Trp broke the Zn-O bonds in the crystal and exposed more highly active Zn on the crystal surface, which easily reacted with sodium oleate. At the same time, Trp increased the concentration of Zn2+ in the pulp, and an appropriate amount of Zn2+ in the solution owned a certain activation effect, which finally improved the adsorption of NaOL on the surface of smithsonite. DFT showed that Trp interacted strongly with smithsonite, and the carboxyl O atom of Trp coordinated with Zn on the surface of smithsonite.

Luo A., Chen J.

Smithsonite is an important zinc oxide ore that is mainly recovered through flotation. Previous studies have demonstrated that fatty acid collectors, notably oleic acid, are effective in smithsonite flotation. However, the efficiency of oleic acid is substantially affected by temperature changes. Currently, there is a lack of research on low-temperature collectors for smithsonite flotation. This study aims to determine the flotation recoveries of smithsonite utilizing three novel collectors: sodium lauryl fatty acid amide, dodecyl hydroxamic acid, and 2-ethylhexyl phosphate, as well as the traditional collector, oleic acid. These reagents were examined at various temperatures, dosages, and pH levels using microflotation experiments. The findings indicate that all three of the novel collectors are efficient in recovering smithsonite. Notably, 2-ethylhexyl phosphate can achieve relatively high recovery of smithsonite at low temperatures, which sets it apart from oleic acid. Furthermore, density functional based tight binding (and more) (DFTB+) methods were utilized to disclose the adsorption mechanisms of collectors. Additionally, molecular dynamics simulations were adopted to determine why the use of 2-ethylhexyl phosphate and oleic acid as collectors had different effects on the flotation behaviors of smithsonite at different temperatures. Overall, the results significantly contribute to the understanding of smithsonite flotation at low temperatures.

ZHANG G., GAO Y., WANG M.

Zhou H., Guo J., Zhu G., Xu H., Tang X., Luo X.

The sulfuration pretreatment is essential in enhancing the floatability of zinc oxide ore during the flotation process. The conventional vulcanizing agent employed in the sulfuration process, however, has proven to be ineffective and environmentally unfriendly. The dosage of this agent must be strictly regulated to ensure optimal flotation efficiency of zinc oxide ore, as excessive or insufficient amounts can have a negative impact. To address these issues, a more efficient and environmentally friendly vulcanization agent called sodium thiocyanate (NaSCN) has been introduced to enhance the sulfuration flotation of smithsonite. It also demonstrated the effective sulfidation of smithsonite by sodium thiocyanate, which also exhibits superior vulcanization effects compared to sodium sulfide. By applying NaSCN at a concentration of 6 × 10-4 mol/L, the recovery rate of zinc ore can achieve 88.75 %. Moreover, the vulcanization conditions utilizing sodium thiocyanate offer greater ease of management. The vulcanization mechanism of smithsonite was investigated through FTIR, Zeta potential, and XPS analysis. The findings indicate that the dentate ligand SCN– derived from sodium thiocyanate can undergo chemical adsorption onto the surface of smithsonite through either sulfur (S) or nitrogen (N) elements. The interaction leads to the formation of zinc-thiocyanate anions, which enhance the surface hydrophobicity and expand the mineral collection sites. The overall findings suggest that sodium thiocyanate exhibits promising potential as a highly efficient vulcanization agent for smithsonite, providing valuable insights for the flotation of this mineral.

Liao R., Wen S., Liu J., Bai S., Feng Q.

The significance of zinc oxide ore as an important supplementary source to meet the growing demand for zinc resources has been underscored. In this study, a combination of dodecylamine (DDA) and sodium diethyl dithiocarbamate (DDTC) was employed as a mixed collector system to enhance the flotation of smithsonite. The utilization of the DDA/DDTC mixed collector led to a remarkable flotation performance improvement of nearly 30% compared to using 2 × 10-4 M DDA alone. The evidence for the synergistic effect of DDA and DDTC was demonstrated through measurements of adsorption capacity and zeta potential. Moreover, solution surface tension measurements indicated that the mixed collector system contributed to a decrease in surface tension. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were employed to verify the simultaneous physisorption and chemisorption of DDA and DDTC on the sulfidized smithsonite surface. Additionally, the variation in contact angles demonstrated that the mixed collector effectively enhanced the hydrophobicity of smithsonite. Molecular dynamics (MD) simulations revealed that DDTC and DDA undergo multilayer adsorption on the smithsonite (1 0 1) surface, with DDTC promoting the adsorption of DDA.

Liu M., Chen D., Hu B., He P., Chen Y., Zeng H., Zhang C., Zhu J.

Ammonium sulfate [(NH4)2SO4] is an effective activator of malachite sulfidization flotation. In this work, we explored the effects of ammonium ion (NH4+) and copper ion (Cu2+) on malachite sulfidization flotation and investigated the underlying mechanism. Flotation experiments demonstrated that NH4+ can not only eliminate the negative effects of Cu2+, but also work together with Cu2+ to further promote malachite sulfidization flotation in a certain concentration range. Zeta potential, SEM-EDS, and X-ray photoelectron spectroscopy analysis results indicated that the single Cu2+ weakened the oxidation of S (II) species on the malachite surface and reduced the formation of sulfides. In the presence of NH4+, Cu2+ did not inhibit the formation of sulfides on malachite surface but worked with NH4+ to promote it. Aqueous speciation calculation and adsorption test revealed that NH4+ and Cu2+ interacted to form Cu (II)–NH3 complexes, which reacts with S (II) species to form a copper sulfide substance that is more easily adsorbed on the malachite surface than the copper sulfide colloid formed by the reaction between Cu2+ and S (II) species. This leads to the improvement of surface sulfidization.

Liao R., Wen S., Liu J., Bai S., Feng Q.

The escalating demand for zinc resources has been positioning zinc oxide ore as an invaluable supplementary resource to cater to zinc supply requirements. There is now a growing focus on optimizing the efficient flotation of zinc oxide ore. In this study, experiments were conducted using dodecylamine (DDA) and octyl hydroxamic acid (OHA) as combined collectors, along with pre-sulfidization by sodium sulfide, to enhance smithsonite flotation. The use of the DDA–OHA combined collector resulted in a significant improvement of over 25% in the recovery when compared with the use of DDA as a single collector. Adsorption capacity measurements and zeta potential measurements provided evidence for the synergistic effect of DDA and OHA. Solution surface tension measurements indicated that the combined collector system helped stabilize the flotation foam. Analysis of treated smithsonite by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy further verified the chemical and physical adsorption of DDA and OHA on the surface of smithsonite. The measurement of contact angles of treated smithsonite showed that the combined collector effectively increased the hydrophobicity of the mineral. Molecular dynamics simulations suggested that OHA and DDA undergo multilayer adsorption on the sulfidized smithsonite (1 0 1) surface and that the presence of OHA promotes the adsorption of DDA.

Liao R., Feng Q., Wen S., Zuo Q., Zhou Y., Liu J.

In this study, the effects of hydrolytic polymaleic anhydride (HPMA) on the flotation separation of fine smithsonite from fine calcite in the Na2S-Pb(II)-xanthate system were investigated. The micro-flotation tests showed that the floatability of fine calcite was significantly decreased after the addition of 40 mg/L of HPMA, while only a slight effect was observed on smithsonite. The inductively coupled plasma optical emission spectrometry (ICP-OES) analysis revealed that the addition of 50 mg/L HPMA dissolved 16.62 mg/L of Ca2+ ions from the calcite surface into the pulp. The analysis of total organic carbon (TOC) and Fourier transform infrared spectroscopy (FTIR) revealed that the HPMA could also chemical adsorption onto the calcite surface. The ultraviolet-visible spectroscopy and zeta potential results indicated that the HPMA blocked the formation of Pb(Ⅱ)-S species on the calcite surface, thus reducing the adsorption of xanthate. The X-ray photoelectron spectroscopy (XPS) analysis further confirmed that the HPMA achieved chemisorption and formed Ca-COOM onto the calcite surface, and the Pb and S contents on the calcite surface decreased significantly after HPMA treatment in the Na2S-Pb(II) system. The molecular dynamics simulation results agreed with the flotation test and measurements analysis results in this work, which explains that HPMA shows stronger adsorption performance on the calcite surface.