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Electrokinetic and flotation behaviors of hemimorphite in the presence of sodium oleate
Minerals Engineering 84 (2015) 74–76
Contents lists available at ScienceDirect
Minerals Engineering journal homepage: www.elsevier.com/locate/mineng
Electrokinetic and flotation behaviors of hemimorphite in the presence of sodium oleate Cheng Liu, Qiming Feng, Guofan Zhang ⇑ School of Mineral Processing and Bioengineering, Central South University, Changsha 410083, China
a r t i c l e
i n f o
Article history: Received 2 August 2015 Revised 11 September 2015 Accepted 22 September 2015 Available online 3 October 2015 Keywords: Sodium oleate Hemimorphite Flotation
a b s t r a c t The electrokinetic and flotation behaviors of hemimorphite in sodium oleate solution were studied. The results of micro-flotation experiments indicate that hemimorphite shows good floatability at pH 4.0–9.0 and pH 11.0. The point of zero charge (PZC) of hemimorphite is pH 5.1. Zeta-potential and FTIR measurements indicate that the mechanism of sodium oleate adsorption on hemimorphite involves both chemical and physical interactions. Sodium oleate mainly reacts with the Zn on the hemimorphite surface. In acid/ base pH range, the aggregation among hemimorphite particles which is more likely caused by hydrophobic interaction than electrostatic interaction improves hemimorphite’s floatability. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction Fatty acid salts are widely used as anionic collectors for silicate and oxide minerals (Fuerstenau and Pradip, 2005; Fan and Rowson, 2000). The mechanisms including individual ion electrostatic adsorption, chemical adsorption, ion–molecule dimeric complex adsorption, and the coadsorption of ion and molecule have ever been proposed for sodium oleate flotation (Somasundaran, 1983; Rao et al., 1991; Yin et al., 2012). Zinc is an important base metal in the galvanizing and automobile manufacturing industries and is conventionally produced from minerals (sphalerite, smithsonite, hemimorphite, etc.) by flotation routes (Ciccu et al., 1979; Pereira and Peres, 2005; Abkhoshk et al., 2014). Hemimorphite is a sorosilicate of formula Zn4Si2O7(OH)2H2O, was chosen because it is one of the most commercially important minerals for the extraction of zinc (Nakamura et al., 1977; Li et al., 2013). It is becoming increasingly attractive due to the depletion of zinc sulfide ores and the restrictions on sulfur emission (Yuan et al., 2010). There is significant research concerning the layer charge, anion-retention capacity, adsorption, hydrophilicity and hydrophobicity related to the adsorption about the silicate minerals minerals (Liu et al., 2015; Yu et al., 2015; Rath et al., 2014). However, very little research has been conducted concerning the flotation of hemimorphite using sodium oleate as collectors. The flotation mechanism of hemimorphite in presence of sodium oleate is unclear.
⇑ Corresponding author. E-mail address: [email protected] (G. Zhang). http://dx.doi.org/10.1016/j.mineng.2015.09.016 0892-6875/Ó 2015 Elsevier Ltd. All rights reserved.
In this study, the adsorption mechanism of sodium oleate (NaOl) on hemimorphite is studied by zeta potential measurements and FTIR analysis. The aggregation/dispersion of the hemimorphite are investigated by turbidity measurements.
2. Experimental The hemimorphite used for all experiments was obtained from Changsha, Hunan Province, China. The samples were crushed and ground using an agate mortar. The products were then dry sieved to obtain 74 lm material. Micro-flotation experiments were performed in a 40-mL hitch groove flotation cell. The purified mineral particles (2.0 g) were placed in a Plexiglas cell, which was then filled with 35 mL of distilled water. The pH of the suspension was adjusted by HCl or NaOH for 3 min, the collector was added and agitated for 3 min, and then, the pH of the suspension was measured before the flotation. The zeta-potentials were measured using a Coulter Delsa440sx Zeta analyzer instrument. The suspensions with small amount of the minerals were dispersed in a beaker magnetically stirred for 15 min in the presence of different pH value, turbidity of the suspension was measured by WGZ-3(3A) spectrometer, FTIR spectra were obtained as KBr pellets using a Fourier transform infrared spectrometer of Nicolet FTIR-740. The sample was not mixed with KBr. (0.25)g hemimorphite and (100)ml of the surfactant solution were taken into a. graduated cylinder with a glass stopper. After adding small amounts of sodium hydroxide or hydrochloric acid solutions to obtain the desired pH, the cylinder was inverted 20 times. The suspension was then allowed to settle for 3 min.
75
C. Liu et al. / Minerals Engineering 84 (2015) 74–76
864.9
1087.4
933.5
600.8 677.1 559.8 448.9
1712.8 1559.2 1446.5 1424.9 1634.6
The effects of pH value on the zeta potential and flotation recovery of hemimorphite are shown in Fig. 1. The point of zero charge (PZC) of hemimorphite occurred at pH 5.1. In the presence of sodium oleate, the PZC of hemimorphite changed slightly, and the PZC of hemimorphite moved from about pH 5.1 to 2.3. In 2 10 4 mol/L sodium oleate solution, the hemimorphite showed a better floatability throughout the pH range of 4.0–9.0 and pH 11.0. The flotation recovery reached a maximum value at pH 8.0 which is attributed to increases in the concentrations of oleate anions and ionic-molecular complexes.
3445.0
3.1. Electrokinetic and flotation behavior of hemimorphite
2921.3 2851.2
3446.5
3. Results and discussions
721.8
Turbidity and pH of the suspension were measured by WGZ-3(3A) and pH spectrometer, respectively.
4000
3500
3000
2500
2000
1500
1000
500
Wavenumbers (cm-1) Fig. 2. FT-IR spectra of sodium oleate, sphalerite, smithsonite, and hemimorphite.
3.2. FITR analysis
1457
2851
2922
Fig. 2 shows the FT-IR spectra of sodium oleate, sphalerite, smithsonite and hemimorphite. In the FT-IR spectrum of sodium oleate, the bands at 2921.3 cm 1 and 2851.2 cm 1 can be attributed to the CAH stretching vibration of the ACH2A and ACH3 groups, respectively. The bands at 1712.8 cm 1, 1559.2 cm 1, 1446.5 cm 1, and 1424.9 cm 1 can be attributed to the ACOOA vibration. Among these bands, the band at 1712.9 cm 1 can be attributed to the C@O stretching vibration, whereas the band at 1559.2 cm 1 can be attributed to the ACOOCA asymmetric stretching vibration. The bands at 1446.5 cm 1 and 1424.9 cm 1 can be attributed to the ACOOCA symmetric stretching vibration. The band at 721.8 cm 1 can be attributed to the A(CH2)nA deformation (Nájera, 2007; Tandon et al., 2001). Several characteristic bands for hemimorphite were observed (Poulet and Mathieu, 1975). The FTIR spectra of hemimorphite at pH 4.0, 7.0, and 11.0 conditioned with NaOl are shown in Fig. 3. Two strong bands in the 3000–2700 cm 1 region and a weak transmittance band in 1470– 1440 cm 1 region were observed and shown in Fig. 3. The peaks at 2922 cm 1 and 2851 cm 1 can be attributed to the CAH stretching vibration of the ACH2A and ACH3 group, respectively (Fukami et al., 1998; Tandon et al., 2001). The peak at 1457 cm 1 belonged to ZnAOl complex appeared on hemimorphite surfaces. Fig. 4 shows the turbidity of hemimorphite as a function of pH in presence and absence of sodium oleate. The turbidity results demonstrated that dispersibility of hemimorphite in pure water
Fig. 3. FT-IR spectra of hemimorphite untreated and treated by 2 10 NaOl at different pH.
4
mol/L
Zeta potential (mV) Fig. 4. Turbidity of hemimorphite untreated and treated by 2 10 a function of pH.
Fig. 1. Zeta potential of hemimorphite in presence and absence of sodium oleate, flotation hemimorphite as a function of the conditioning pH with sodium oleate.
4
mol/L NaOl as
is strong, which shows the same tendency with the absolute value of zeta potential without sodium oleate (see Fig. 1), after treated with 2 10 4 mol/L sodium oleate, the turbidity decreased
76
C. Liu et al. / Minerals Engineering 84 (2015) 74–76
significantly indicating that stable and excellent flocculation can be obtained in the weak acidic conditions. Generally, the phenomena of aggregation can be explained by the extended DLVO theory. The aggregation/dispersion of hemimorphite suspension the presence of sodium oleate showed opposite tendency with the flotation results in Fig. 1. 4. Conclusion The PZC of hemimorphite occurred at pH 5.1. The negative zeta potential of hemimorphite is increased with the increase in pH values. Chemical and physical interactions occurred between the sodium oleate and the mineral surface. Although the negative zeta potential of hemimorphite and the adsorption of sodium oleate on hemimorphite are higher at alkaline pH region, hemimorphite showed a better floatability in the pH range from 4.0 to 9.0 and pH 11.0. The anomalous flotation behavior of hemimorphite using sodium oleate as collector may be attributed to the aggregation or dispersion behavior of hemimorphite in various pH range in the presence of sodium oleate. Acknowledgement The authors acknowledge the support of the Major State Basic Research Development Program of China (973 program) (2014CB643402). References Abkhoshk, R.E., Jorjani, E., Al-Harahsheh, M.S., Rashchi, F., Naazeri, M., 2014. Review of the hydrometallurgical processing of non-sulfide zinc ores. Hydrometallurgy 149, 153–167.
Ciccu, R., Curreli, L., Ghiani, M., 1979. The beneficiation of lean semi oxidized lead– zinc ores. In: Proc. 13th Int. Minerals Process. Cong., Processing of Oxidized and Mixed Oxide-Sulfide Lead–Zinc Ores, Warsaw, pp. 125–145. Fan, X., Rowson, N.A., 2000. The effect of Pb(NO3)2 on ilmenite flotation. Mineral Eng. 13 (2), 205–215. Fuerstenau, D., Pradip, 2005. Zeta potentials in the flotation of oxide and silicate minerals. Adv. Colloid Interface Sci. 114–115, 9–26. Fukami, Y., Maeda, Y., Awazu, K., 1998. Raman and FT-IR studies of photodynamic processes of cholesteryl oleate using IRFELs. Nucl. Instrum. Methods Phys. Res. B 144, 229–235. Li, Cun.-xiong. et al., 2013. Kinetics of hydrothermal sulfidation of synthetic hemimorphite with elemental sulfur. Trans. Nonferrous Met. Soc. China 23, 1815–1821. Liu, Weijun, Zhang, Jie, Wang, Weiqing, et al., 2015. Flotation behaviors of ilmenite, titanaugite, and forsterite using sodium as collector. Miner. Eng. 72, 1–9. Nájera, J.J., 2007. Phase transition behaviour of sodium oleate aerosol particles. Atmos. Environ. 41 (5), 1041–1052. Nakamura, R., Arikata, K., Suginohara, Y., Yanagase, T., 1977. Structure of silicates as studies by trimethylsilylation. Kogaku Shuho-Kyushu Daigaku 50 (5), 635–641. Pereira, C.A., Peres, A.E.C., 2005. Reagents in calamine zinc ores flotation. Miner. Eng. 18, 275–277. Poulet, H., Mathieu, J.P., 1975. Vibration spectra and structure of hemimorphite. Bulletin de la Societe Francaise de Mineral. et de Crystallographica 98, 3–5. Rao, K.H., Cases, J.M., Forssberg, K.S.E., 1991. Mechanism of oleate interaction on salt-type minerals. J. Colloids Interf. 145 (2), 330–347. Rath, Swagat S., Sinha, Nishant, Sahoo, Hrushikesh, et al., 2014. Molecular modeling studies of oleate adsorption on iron oxides. Appl. Surf. Sci. 295, 115–122. Somasundaran, P., 1983. Flotation mechanism based on ion-molecular complexes. J. Central South Inst. Min. Metallurgy 8 (S2), 59–68 (in chinese). Tandon, P., Raudenkolb, S., Neubert, R.H.H., Rettig, W., Wartewig, S., 2001. X-ray diffraction and spectroscopic studies of oleic acid–sodium oleate. Chem. Phys. Lipids 109, 37–45. Yin, Xihui, Gupta, Vishal, Du, Hao, Wang, Xuming, Miller, Jan D., 2012. Surface charge and wetting characteristics of layered silicate minerals. Adv. Colloid Interface Sci. 179–182, 43–50. Yu, Fushun, Wang, Yuhua, Zhang, Lei, Zhu, Guangli, 2015. Role of oleic acid ionicmolecular complexes in the flotation of spodumene. Miner. Eng. 71, 7–12. Yuan, Tiechui, Cao, Qinyuan, Li, Jie, 2010. Effects of mechanical activation on physicochemical properties and alkaline leaching of hemimorphite. Hydrometallurgy 104, 136–141.
Contents lists available at ScienceDirect
Minerals Engineering journal homepage: www.elsevier.com/locate/mineng
Electrokinetic and flotation behaviors of hemimorphite in the presence of sodium oleate Cheng Liu, Qiming Feng, Guofan Zhang ⇑ School of Mineral Processing and Bioengineering, Central South University, Changsha 410083, China
a r t i c l e
i n f o
Article history: Received 2 August 2015 Revised 11 September 2015 Accepted 22 September 2015 Available online 3 October 2015 Keywords: Sodium oleate Hemimorphite Flotation
a b s t r a c t The electrokinetic and flotation behaviors of hemimorphite in sodium oleate solution were studied. The results of micro-flotation experiments indicate that hemimorphite shows good floatability at pH 4.0–9.0 and pH 11.0. The point of zero charge (PZC) of hemimorphite is pH 5.1. Zeta-potential and FTIR measurements indicate that the mechanism of sodium oleate adsorption on hemimorphite involves both chemical and physical interactions. Sodium oleate mainly reacts with the Zn on the hemimorphite surface. In acid/ base pH range, the aggregation among hemimorphite particles which is more likely caused by hydrophobic interaction than electrostatic interaction improves hemimorphite’s floatability. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction Fatty acid salts are widely used as anionic collectors for silicate and oxide minerals (Fuerstenau and Pradip, 2005; Fan and Rowson, 2000). The mechanisms including individual ion electrostatic adsorption, chemical adsorption, ion–molecule dimeric complex adsorption, and the coadsorption of ion and molecule have ever been proposed for sodium oleate flotation (Somasundaran, 1983; Rao et al., 1991; Yin et al., 2012). Zinc is an important base metal in the galvanizing and automobile manufacturing industries and is conventionally produced from minerals (sphalerite, smithsonite, hemimorphite, etc.) by flotation routes (Ciccu et al., 1979; Pereira and Peres, 2005; Abkhoshk et al., 2014). Hemimorphite is a sorosilicate of formula Zn4Si2O7(OH)2H2O, was chosen because it is one of the most commercially important minerals for the extraction of zinc (Nakamura et al., 1977; Li et al., 2013). It is becoming increasingly attractive due to the depletion of zinc sulfide ores and the restrictions on sulfur emission (Yuan et al., 2010). There is significant research concerning the layer charge, anion-retention capacity, adsorption, hydrophilicity and hydrophobicity related to the adsorption about the silicate minerals minerals (Liu et al., 2015; Yu et al., 2015; Rath et al., 2014). However, very little research has been conducted concerning the flotation of hemimorphite using sodium oleate as collectors. The flotation mechanism of hemimorphite in presence of sodium oleate is unclear.
⇑ Corresponding author. E-mail address: [email protected] (G. Zhang). http://dx.doi.org/10.1016/j.mineng.2015.09.016 0892-6875/Ó 2015 Elsevier Ltd. All rights reserved.
In this study, the adsorption mechanism of sodium oleate (NaOl) on hemimorphite is studied by zeta potential measurements and FTIR analysis. The aggregation/dispersion of the hemimorphite are investigated by turbidity measurements.
2. Experimental The hemimorphite used for all experiments was obtained from Changsha, Hunan Province, China. The samples were crushed and ground using an agate mortar. The products were then dry sieved to obtain 74 lm material. Micro-flotation experiments were performed in a 40-mL hitch groove flotation cell. The purified mineral particles (2.0 g) were placed in a Plexiglas cell, which was then filled with 35 mL of distilled water. The pH of the suspension was adjusted by HCl or NaOH for 3 min, the collector was added and agitated for 3 min, and then, the pH of the suspension was measured before the flotation. The zeta-potentials were measured using a Coulter Delsa440sx Zeta analyzer instrument. The suspensions with small amount of the minerals were dispersed in a beaker magnetically stirred for 15 min in the presence of different pH value, turbidity of the suspension was measured by WGZ-3(3A) spectrometer, FTIR spectra were obtained as KBr pellets using a Fourier transform infrared spectrometer of Nicolet FTIR-740. The sample was not mixed with KBr. (0.25)g hemimorphite and (100)ml of the surfactant solution were taken into a. graduated cylinder with a glass stopper. After adding small amounts of sodium hydroxide or hydrochloric acid solutions to obtain the desired pH, the cylinder was inverted 20 times. The suspension was then allowed to settle for 3 min.
75
C. Liu et al. / Minerals Engineering 84 (2015) 74–76
864.9
1087.4
933.5
600.8 677.1 559.8 448.9
1712.8 1559.2 1446.5 1424.9 1634.6
The effects of pH value on the zeta potential and flotation recovery of hemimorphite are shown in Fig. 1. The point of zero charge (PZC) of hemimorphite occurred at pH 5.1. In the presence of sodium oleate, the PZC of hemimorphite changed slightly, and the PZC of hemimorphite moved from about pH 5.1 to 2.3. In 2 10 4 mol/L sodium oleate solution, the hemimorphite showed a better floatability throughout the pH range of 4.0–9.0 and pH 11.0. The flotation recovery reached a maximum value at pH 8.0 which is attributed to increases in the concentrations of oleate anions and ionic-molecular complexes.
3445.0
3.1. Electrokinetic and flotation behavior of hemimorphite
2921.3 2851.2
3446.5
3. Results and discussions
721.8
Turbidity and pH of the suspension were measured by WGZ-3(3A) and pH spectrometer, respectively.
4000
3500
3000
2500
2000
1500
1000
500
Wavenumbers (cm-1) Fig. 2. FT-IR spectra of sodium oleate, sphalerite, smithsonite, and hemimorphite.
3.2. FITR analysis
1457
2851
2922
Fig. 2 shows the FT-IR spectra of sodium oleate, sphalerite, smithsonite and hemimorphite. In the FT-IR spectrum of sodium oleate, the bands at 2921.3 cm 1 and 2851.2 cm 1 can be attributed to the CAH stretching vibration of the ACH2A and ACH3 groups, respectively. The bands at 1712.8 cm 1, 1559.2 cm 1, 1446.5 cm 1, and 1424.9 cm 1 can be attributed to the ACOOA vibration. Among these bands, the band at 1712.9 cm 1 can be attributed to the C@O stretching vibration, whereas the band at 1559.2 cm 1 can be attributed to the ACOOCA asymmetric stretching vibration. The bands at 1446.5 cm 1 and 1424.9 cm 1 can be attributed to the ACOOCA symmetric stretching vibration. The band at 721.8 cm 1 can be attributed to the A(CH2)nA deformation (Nájera, 2007; Tandon et al., 2001). Several characteristic bands for hemimorphite were observed (Poulet and Mathieu, 1975). The FTIR spectra of hemimorphite at pH 4.0, 7.0, and 11.0 conditioned with NaOl are shown in Fig. 3. Two strong bands in the 3000–2700 cm 1 region and a weak transmittance band in 1470– 1440 cm 1 region were observed and shown in Fig. 3. The peaks at 2922 cm 1 and 2851 cm 1 can be attributed to the CAH stretching vibration of the ACH2A and ACH3 group, respectively (Fukami et al., 1998; Tandon et al., 2001). The peak at 1457 cm 1 belonged to ZnAOl complex appeared on hemimorphite surfaces. Fig. 4 shows the turbidity of hemimorphite as a function of pH in presence and absence of sodium oleate. The turbidity results demonstrated that dispersibility of hemimorphite in pure water
Fig. 3. FT-IR spectra of hemimorphite untreated and treated by 2 10 NaOl at different pH.
4
mol/L
Zeta potential (mV) Fig. 4. Turbidity of hemimorphite untreated and treated by 2 10 a function of pH.
Fig. 1. Zeta potential of hemimorphite in presence and absence of sodium oleate, flotation hemimorphite as a function of the conditioning pH with sodium oleate.
4
mol/L NaOl as
is strong, which shows the same tendency with the absolute value of zeta potential without sodium oleate (see Fig. 1), after treated with 2 10 4 mol/L sodium oleate, the turbidity decreased
76
C. Liu et al. / Minerals Engineering 84 (2015) 74–76
significantly indicating that stable and excellent flocculation can be obtained in the weak acidic conditions. Generally, the phenomena of aggregation can be explained by the extended DLVO theory. The aggregation/dispersion of hemimorphite suspension the presence of sodium oleate showed opposite tendency with the flotation results in Fig. 1. 4. Conclusion The PZC of hemimorphite occurred at pH 5.1. The negative zeta potential of hemimorphite is increased with the increase in pH values. Chemical and physical interactions occurred between the sodium oleate and the mineral surface. Although the negative zeta potential of hemimorphite and the adsorption of sodium oleate on hemimorphite are higher at alkaline pH region, hemimorphite showed a better floatability in the pH range from 4.0 to 9.0 and pH 11.0. The anomalous flotation behavior of hemimorphite using sodium oleate as collector may be attributed to the aggregation or dispersion behavior of hemimorphite in various pH range in the presence of sodium oleate. Acknowledgement The authors acknowledge the support of the Major State Basic Research Development Program of China (973 program) (2014CB643402). References Abkhoshk, R.E., Jorjani, E., Al-Harahsheh, M.S., Rashchi, F., Naazeri, M., 2014. Review of the hydrometallurgical processing of non-sulfide zinc ores. Hydrometallurgy 149, 153–167.
Ciccu, R., Curreli, L., Ghiani, M., 1979. The beneficiation of lean semi oxidized lead– zinc ores. In: Proc. 13th Int. Minerals Process. Cong., Processing of Oxidized and Mixed Oxide-Sulfide Lead–Zinc Ores, Warsaw, pp. 125–145. Fan, X., Rowson, N.A., 2000. The effect of Pb(NO3)2 on ilmenite flotation. Mineral Eng. 13 (2), 205–215. Fuerstenau, D., Pradip, 2005. Zeta potentials in the flotation of oxide and silicate minerals. Adv. Colloid Interface Sci. 114–115, 9–26. Fukami, Y., Maeda, Y., Awazu, K., 1998. Raman and FT-IR studies of photodynamic processes of cholesteryl oleate using IRFELs. Nucl. Instrum. Methods Phys. Res. B 144, 229–235. Li, Cun.-xiong. et al., 2013. Kinetics of hydrothermal sulfidation of synthetic hemimorphite with elemental sulfur. Trans. Nonferrous Met. Soc. China 23, 1815–1821. Liu, Weijun, Zhang, Jie, Wang, Weiqing, et al., 2015. Flotation behaviors of ilmenite, titanaugite, and forsterite using sodium as collector. Miner. Eng. 72, 1–9. Nájera, J.J., 2007. Phase transition behaviour of sodium oleate aerosol particles. Atmos. Environ. 41 (5), 1041–1052. Nakamura, R., Arikata, K., Suginohara, Y., Yanagase, T., 1977. Structure of silicates as studies by trimethylsilylation. Kogaku Shuho-Kyushu Daigaku 50 (5), 635–641. Pereira, C.A., Peres, A.E.C., 2005. Reagents in calamine zinc ores flotation. Miner. Eng. 18, 275–277. Poulet, H., Mathieu, J.P., 1975. Vibration spectra and structure of hemimorphite. Bulletin de la Societe Francaise de Mineral. et de Crystallographica 98, 3–5. Rao, K.H., Cases, J.M., Forssberg, K.S.E., 1991. Mechanism of oleate interaction on salt-type minerals. J. Colloids Interf. 145 (2), 330–347. Rath, Swagat S., Sinha, Nishant, Sahoo, Hrushikesh, et al., 2014. Molecular modeling studies of oleate adsorption on iron oxides. Appl. Surf. Sci. 295, 115–122. Somasundaran, P., 1983. Flotation mechanism based on ion-molecular complexes. J. Central South Inst. Min. Metallurgy 8 (S2), 59–68 (in chinese). Tandon, P., Raudenkolb, S., Neubert, R.H.H., Rettig, W., Wartewig, S., 2001. X-ray diffraction and spectroscopic studies of oleic acid–sodium oleate. Chem. Phys. Lipids 109, 37–45. Yin, Xihui, Gupta, Vishal, Du, Hao, Wang, Xuming, Miller, Jan D., 2012. Surface charge and wetting characteristics of layered silicate minerals. Adv. Colloid Interface Sci. 179–182, 43–50. Yu, Fushun, Wang, Yuhua, Zhang, Lei, Zhu, Guangli, 2015. Role of oleic acid ionicmolecular complexes in the flotation of spodumene. Miner. Eng. 71, 7–12. Yuan, Tiechui, Cao, Qinyuan, Li, Jie, 2010. Effects of mechanical activation on physicochemical properties and alkaline leaching of hemimorphite. Hydrometallurgy 104, 136–141.