Jinhong Zhang

Interests

Teaching

mineral processing, surface chemistry, surface characterization, environmental engineering

Research

mineral processing: crushing, grinding, sizing, gravity separation, flotation, sedimentation, filtration;surface chemistry: dispersion, coagulation, flocculation;industry waste treatment: mine tailing, fly ash, geopolymerization, alkali-activation to make construction material, applying waste water in mineral processing;surface characterization: FTIR, SEM/EDS, Atomic Force Microscopy (surface force measurement, surface imaging, nano-indentation)

Courses

Scholarly Contributions

Chapters

• Zhang, J., & Zhang, W. (2014). An Atomic Force Microscopy Study of the Adsorption of Collectors on Chalcopyrite. In Microscopy: advances in scientific research and education(pp 967-973). ISBN 978-84-942134-4-1: Formatex Research Center.
• Zhang, J., & Zhang, W. (2010). Applying an Atomic Force Microscopy in the Study of Mineral Flotation. In Microscopy: Science, Technology, Applications and Education(pp 2028-2034). ISBN-13: 978-84-614-6191-2: Formatex Research Center.

Journals/Publications

• Zhang, J. (2022). Zhang, J.; Zhang, W. AFM Image Analysis of the Adsorption of Xanthate and Dialkyl Dithiophosphate on Chalcocite. Minerals, 12(8), 34. doi:https://doi.org/10.3390/min12081018
• Zhang, J. (2021). An Investigation of the Adsorption of Xanthate on Bornite in Aqueous Solutions using an Atomic Force Microscope. Minerals, 24.
• Zhang, J., & An, D. (2020). A Study of Temperature Effect on the Xanthate’s Performance during Chalcopyrite Flotation. Minerals, 10(5), 426. doi:https://doi.org/10.3390/min10050426
• Zhang, J., & Feng, Q. (2020). The making of Class C fly ash as high-strength precast construction material through geopolymerization. Mining, Metallurgy & Exploration. doi:10.1007/s42461-020-00283-w
• Zhang, J., & An, D. (2019). A micro-scale investigation of the adsorption of collectors on bastnaesite. Mining, Metallurgy & Exploration.
• Zhang, J., & Feng, Q. (2019). Making mine tailings as precast construction materials through alkali-activation. Mining, Metallurgy & Exploration.
• Zhang, J., & Zhang, W. (2015). An AFM Study of the Adsorption of Collector on Chalcocite. 2015 SME Annual Meeting and Exhibit, preprint, 15-138.
• Zhang, J., Zhang, W., An, D., & Feng, Q. (2014). A study of geopolymerization of mine tailings as construction materials. XXVII Internal Mineral Processing Congress, #586.
• Zhang, J., Zhang, W., Feng, Q., & An, D. (2014). An AFM Study of the Adsorption of Oleic Acid on Fluorite. 2014 SME Annual Meeting and Exhibit, preprint.
• Zhang, J., & Zhang, W. (2012). Adsorption of collectors on chalcopyrite surface studied by an AFM. Separation Technologies for Minerals, Coal, and Earth Resources, 65-73.
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  Abstract: An atomic force microscopy (AFM) has been applied to study the adsorption of collectors on chalcopyrite surface in aqueous solutions. AFM images showed that collectors absorbed on mineral surface in patches after the chalcopyrite sample was soaked in potassium ethyl xanthate (KEX) or potassium amyl xanthate (PAX) solutions at pH 11. At the same time, as shown by the obtained AFM force curves, the adhesion between the AFM tip and the substrate increased greatly due to the collector adsorption. Rinsing with ethanol removed the patch-like absorbate instantly from the chalcopyrite surface. Patch-like absorbate was also observed on chalcopyrite surface in the solutions of two industrial collectors, i.e., Col-1 and Col-2. The potential impact of this patches adsorption on chalcopyrite flotation is discussed.
• Zhang, J., & Zhang, W. (2012). An AFM study of collectors' adsorption on minerals in copper/molybdenum flotation. 2012 SME Annual Meeting and Exhibit 2012, SME 2012, Meeting Preprints, 547-552.
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  Abstract: An atomic force microscopy (AFM) has been applied to study the adsorption of collectors on mineral surfaces in a copper/molybdenum flotation system. AFM images show that collectors absorb on chalcopyrite surface in patches at pH 11. A study of temperature effect on surface morphology excludes the possibility that these patches are nanobubbles forming on hydrophobized mineral surface. Hydrocarbon oil absorbs on molybdenite quickly, while KEX (potassium ethyl xanthate) has little affinity for molybdenite. Pyrite is much more reactive in water and its surface is easily coated in Ca(OH) 2 solutions at pH 11. Based on the obtained AFM images, the adsorption of chemicals on mineral surface and its impact on copper/molybdenum flotation were discussed. Copyright © 2012 by SME.
• Zhang, J., & Zhang, W. (2012). Multi-scale investigation of applying secondary effluent in sulfide flotation. Water in Mineral Processing - Proceedings of the 1st International Symposium, 279-290.
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  Abstract: The fact that froth flotation consumes a large amount of water, even though it is one of the most efficient methods to process sulfide minerals, brings a higher pressure from the sustainable development due to increasing population and its demand of more portable water. Pioneering work of applying secondary effluent in sulfide flotation (Fisher and Rudy, 1976) showed a 2.4% reduction in Cu recovery and 16.2% reduction in molybdenum recovery when secondary effluent was used. It was also postulated that the organic carbon, in the form of humic acid, in the effluent was the most deleterious constituent causing the losses in metal recovery. We carried out a systemic investigation in both microscopic and macroscopic aspects on the possibility of using secondary effluent in sulfide flotation. AFM images showed that collectors adsorbed on mineral surface (chalcopyrite and molybdenite) in a similar manner in both clean water and treated secondary effluent. Lab flotation tests showed that the Cu and Mo recoveries obtained with treated secondary effluent were comparable to those obtained with tap water. The findings of present multi-scale investigation will help provide a cost-efficient solution to treat low quality water and mitigate its impact, and finally succeed technically in applying secondary effluent in sulfide flotation.
• Zhang, J., Ahmari, S., & Zhang, L. (2012). 'Effects of activator type/concentration and curing temperature on alkali-activated binder based on copper mine tailings. Journal of Materials Science, 47, 5933–5945.
• Siddiqui, S., Zhang, J., Keswani, M., Fuerst, A., & Raghavan, S. (2011). Study of interaction between silicon surfaces in dilute ammonia peroxide mixtures (APM) and their components using atomic force microscope (AFM). Microelectronic Engineering, 88(12), 3442-3447.
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  Abstract: Force measurements have been conducted between H-terminated Si surface and Si tip in DI-water, NH4OH:H2O (1:100), H2O 2:H2O (1:100) and NH4OH:H2O 2:H2O (1:1:100-1:1:500) solutions as a function of immersion time using atomic force microscopy (AFM). The approach force curve results show attractive forces in DI-water, NH4OH:H2O (1:100) and H2O2:H2O (1:100) solutions at separation distances of less than 10 nm for all immersion times (2, 10 and 60 min) investigated in this study. In the case of dilute ammonia-hydrogen peroxide mixtures, the interaction forces are purely repulsive within 2 min of immersion time. The adhesion forces have also been measured between the surface and the tip in DI-water, NH4OH:H2O (1:100) and H2O 2:H2O (1:100) solutions. The magnitude of the adhesion force is in the range of 0.8-10.5 nN in these solutions. In dilute APM solutions, no adhesion force is measured between the surface and the tip and repulsive forces dominated at all separation distances. © 2009 Elsevier B.V. All rights reserved.
• Zha, Z., Cohn, C., Dai, Z., Qiu, W., Zhang, J., & Xiaoyi, W. u. (2011). Nanofibrous lipid membranes capable of functionally immobilizing antibodies and capturing specific cells. Advanced Materials, 23(30), 3435-3440.
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  PMID: 21721057;PMCID: PMC3175633;Abstract: Polymerizable cholesteryl-succinyl silane was synthesized and fabricated into stable nanofibrous lipid membranes using a combined sol-gel and electrospinning process. The resulting nanofibrous lipid membranes are capable of functionally immobilizing membrane proteins such as antibodies, thereby enabling targeted cell capture via the antigen-antibody interactions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
• Zhang, J. (2011). Synthesis and characterization of mine tailings-based geopolymers. Construction and Building Materials, 25(9), 3773-3781.
• Zhang, J., Cohn, C., Qiu, W., Zha, Z., Dai, Z., & Xiaoyi, W. u. (2011). Atomic force microscopy of electrospun organic-inorganic lipid nanofibers. Applied Physics Letters, 99(10).
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  Abstract: An organic-inorganic hybridization strategy has been proposed to synthesize polymerizable lipid-based materials for the creation of highly stable lipid-mimetic nanostructures. We employ atomic force microscopy (AFM) to analyze the surface morphology and mechanical property of electrospun cholesteryl-succinyl silane (CSS) nanofibers. The AFM nanoindentation of the CSS nanofibers reveals elastic moduli of 55.3±27.6 to 70.8±35 MPa, which is significantly higher than the moduli of natural phospholipids and cholesterols. The study shows that organic-inorganic hybridization is useful in the design of highly stable lipid-based materials. © 2011 American Institute of Physics.
• Zhang, J., & Zhang, W. (2010). An AFM study of chalcopyrite surface in aqueous solution. SME Annual Meeting and Exhibit 2010, 535-539.
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  Abstract: The surface of chalcopyrite was studied in situ in aqueous solution by an atomic force microscopy (AFM). The AFM images showed that some absorbate in patches was detected on the mineral surface, after the chalcopyrite sample was soaked in 5×10-4M potassium ethyl xanthate (KEX) solution at pH 11 for 10 minutes. These patches increased in size with time elapsing. At the same time, as shown by the obtained AFM force curves, the adhesion between the AFM tip and the substrate increased greatly due to the adsorption. Rinsing with ethanol removed the absorbate from the chalcopyrite surface, as well as the big adhesion observed in KEX solution.
• Zhang, J., Wiyono, S., Lee, P., & Xiao, W. (2009). Surface characterization of xanthate adsorption on molybdenite. SME Annual Meeting and Exhibit and CMA's 111th National Western Mining Conference 2009, 2, 485-490.
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  Abstract: Surface characterization techniques, i.e. contact angle measurement, atomic force microscopy (AFM) surface force and surface imaging measurement, were applied to investigate the molybdenite surface in aqueous solution. It was shown that the cleaved basal surface of molybdenite was very hydrophobic with a 92 degree water contact angle. The non-polar component of the solid surface free energy is 50.52 mJ/m2 while the polar components are almost zero. The solid surface was not reactive and was only weakly charged at the pH 6. When the aqueous media changes from water to 1×10-4 M KEX solution, the measured contact angle, adhesion force and surface roughness all increase slightly. However, ethanol rinsing made the surface change back to the bare substrate. It was suggested that the hydrophobic chemical, i.e. dixanthogen, which was shown in the morphology of patches by the AFM image, physically adsorbed on the hydrophobic molybdenite surface through the hydrophobic interaction.
• Zhang, J., & Yoon, R. (2008). An AFM study of the surface force between TiO₂ surfaces in C_NTACl solutions. Hydrometallurgy 2008: Proceedings of the 6th International Symposium, 1134-1142.
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  Abstract: Direct surface force measurements have been carried out between titania surfaces in water and in CnTACl (n = 14, 18) solutions using an Atom Force Microscope (AFM). It was found that the surface potential for rutile is about -50mv. The Hamaker constant A131 is 4±1×10 -20 J for rutile in water. In CnTACl (n = 14, 18) surfactant solutions, the force curves show a repulsion/attraction/repulsion transition changing with surfactant concentration. The strongest long range attraction was observed between the TiO2 surfaces in C nTACl solutions in the vicinity of respective p.c.n. (point of charge neutralization), which decreases with surfactant chain length increasing. The long-range attractive hydrophobic force was discussed in terms of the charged-patch model of Miklavic et al. (1994) and the model proposed by Eriksson et al. (1989). The discussion sheds light on the origin of the long-range attractions observed between hydrophobic surfaces.
• Zhang, J., Yoon, R., & Eriksson, J. C. (2007). AFM surface force measurements conducted with silica in C_nTACl solutions: Effect of chain length on hydrophobic force. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 300(3 SPEC. ISS.), 335-345.
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  Abstract: Surface forces were measured using an AFM with silica surfaces immersed in CnTACl (n = 12-18) solutions in the absence of added salt. The results showed long-range attractive forces that cannot be explained by the DLVO theory. The long-range attractions increased with increasing surfactant concentration, reaching a maximum at the point of charge neutralization (p.c.n.) and then decreased. The long-range forces decayed exponentially, with the decay lengths increasing from 3 to 32 nm as the chain length of the surfactants increased from C-12 to C-18. The measured forces can be fitted to the charged-patch model of Miklavic et al. [S.J. Miklavic, D.Y.C. Chan, L.R. White, T.W. Healy, J. Phys. Chem. 98 (1994) 9022-9032] by assuming patch sizes that are much larger than the values reported in the literature. It was found that the decay length decreases linearly with the effective concentration of the CH2/CH3 groups of the CnTACl homologues raised to the power of -1/2, which is in line with the Eriksson et al.'s hydrophobic force model derived using a mean-field approach. It appears, therefore, that the long-range attractions observed in the present work are hydrophobic forces originating from changes in water structure across the thin surfactant solution film between the silica surfaces. It is conceivable that hydrocarbon chains in solution disrupt the surface-induced water structure and cause a decrease in hydrophobic force. This observation may also provide an explanation for the very long-range forces observed with silylated, LB-deposited, and thiol-coated surfaces. © 2007 Elsevier B.V. All rights reserved.
• Lobato, E., Zhang, J., Yildirim, I., Yoon, R., & Yordan, J. (2006). Characterization of surface free energies of talc powders using the thin layer wicking technique. 2006 SME Annual Conference - Functional Fillers and Nanoscale Minerals: New Markets/New Horizons, 2006, 101-114.
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  Abstract: Thin layer wicking technique was used to determine the contact angles (Θ) of different liquids on powdered talc samples. The measured contact angles were used to calculate the surface free energies (γ S) of talc and its components, which included dispersion (γ SAB), acidic (γ Sd), basic (γ S+), and acid-base (γ SAB) surface free energies, using the van Oss-Chaudhury-Good (OCG) equation. The surface free energy characterization was conducted on both the basal and edge surfaces. The results showed that talc is a low surface energy solid, and that its basal surfaces are basic, while its edge surfaces are acidic. It has also been found that the hydrophobicity of talc increases with decreasing particle size, indicating that fracture occurs preferentially along the basal surface of talc. As the particle size is reduced beyond a certain limit, however, talc becomes increasingly hydrophilic, indicating that talc begins to fracture along the edge surfaces, thereby exposing more hydrophilic surfaces.
• Zhang, J., Yoon, R. -., Mao, M., & Ducker, W. A. (2005). Effect of dissolved gas on the force between silica and glass in aqueous ocyadecyltrimetylammonium chloride solutions. Australasian Institute of Mining and Metallurgy Publication Series, 659-664.
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  Abstract: Froth flotation relies on an attractive force between a particle and a bubble to selectively extract particles from a mixture. The range and magnitude of this attractive force is an area of ongoing investigation. We describe measurements of the effect of dissolved gases on the long-range attractive surface forces between a silica plate and a glass sphere in aqueous octadecyltrimethylammonium chloride (C18TACl) solutions. The measurements follow on the work of Sakamoto et al (2002) who have concluded that long-range interactions occur in air-equilibrated surfactant solutions but not in degassed solutions. In the present work, we have measured attractive forces that have a much larger in magnitude than the expected van der Waals force in solutions that were degassed by the same procedure used by Sakamoto et al (2002). We find that the forces are most attractive at 5 × 10-6 M18TACl, which is close to the charge compensation point (ccp) of the glass sphere. At this concentration, the attractive force decays exponentially with distance and the decay length is 34 in air-saturated solution, and 38 nm in degassed solutions. In both air-equilibrated and degassed solution, the force is quite sensitive to the concentration of surfactant. The force is also sensitive to the pH. We note that our degassing procedure increases the pH of the solution from about 5.7 to 6.6 (presumably by removal of dissolved CO2). We find that the forces measured in degassed solution can be reproduced by using a solution that was equilibrated in air, then the pH was increased by addition of NaOH. Therefore, we conclude that the main effect of degassing in our experiments is to raise the pH. We show that the range and magnitude of the attractive force decreases in the presence of salt (NaCl). This suggests an electrostatic mechanism for the attraction. Possible mechanisms for the attractive force are examined, including the mechanisms that rely on a patchy coverage of surfactant on the silica surface.
• Zhang, J., Yoon, R., Mao, M., & Ducker, W. A. (2005). Effects of degassing and ionic strength on AFM force measurements in octadecyltrimethylammonium chloride solutions. Langmuir, 21(13), 5831-5841.
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  PMID: 15952830;Abstract: Sakamoto et al. (Langmuir 2002, 18, 5713) conducted AFM force measurements between silica sphere and fused-silica plate in aqueous octadecyltrimethylammonium chloride (C 16TACl) solutions and concluded that long-range attractive force is not observed in carefully degassed solutions. In the present work, AFM force measurements were conducted by following the procedures described by Sakamoto et al. The results showed the presence of an attractive force that was much stronger than the van der Waals force both in air-saturated and degassed solutions. The force was most attractive at 5 × 10 -6 M C 18TACl, where contact angle was maximum. At this concentration, which is close to the charge compensation point (ccp) of the glass sphere, the long-range decay lengths (D) were 34 and 38 nm in air-saturated and degassed solutions, respectively. At 10 -5 M, the decay length decreased from 30 to 4 nm upon degassing. This decrease in decay length can be explained by a pH increase (from 5.7 to 6.6), which in turn causes additional surfactant molecules to adsorb on the surface with inverse orientation. The attractive force was screened by an added electrolyte (NaCl), indicating that the attractive force may be of electrostatic origin. Therefore, the very long decay lengths observed in the absence of electrolyte may be ascribed to the fact that the ccp occurs at a very low surfactant concentration. © 2005 American Chemical Society.
• Mao, M., Zhang, J., Yoon, R., & Ducker, W. A. (2004). Erratum: Thin film of air at the interface between water and smooth hydrophobie solids? (Langmuir (2004) 20 (1843-1849)). Langmuir, 20(10), 4310-.
• Mao, M., Zhang, J., Yoon, R., & Ducker, W. A. (2004). Is there a thin film of air at the interface between water and smooth hydrophobic solids?. Langmuir, 20(5), 1843-1849.
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  Abstract: Optical measurements using an ellipsometer are inconsistent with the existence of continuous air films that are greater than about 0.1 nm in thickness at the interface between water and silicon wafers that have been rendered hydrophobic through the adsorption of silane agents. If adsorbed air consists of discrete bubbles, then the separation between the bubbles must be much greater than the radius of a bubble. For example, an approximate calculation for 80 nm radius bubbles that are attached with the macroscopic contact angle shows that the minimum spacing consistent with our data is in the range of 5 μm to infinite separation, depending on the sample. Although these putative bubbles would be sparsely distributed, we cannot rule out a density that is great enough to affect surface force apparatus measurements. A new variant of the multiple incidence method for ellipsometry is described and used to decrease the error in determining the thickness of adsorbed films.

Proceedings Publications

• Zhang, J., & Feng, Q. (2019, Feb 25-Feb 27). APPLYING FLY ASH AS A HIGH STRENGTH WATER-RESISTANT PRECAST CONSTRUCTION MATERIAL THROUGH GEOPOLYMERIZATION. In 2019 SME Annual Meeting and Exhibit, preprint.
• Zhang, J., & Zhang, W. (2018, September). An AFM Study of the Adsorption of Amyl Xanthate on Copper Sulfides. In XXIX Internal Mineral Processing Congress.
• Zhang, J., An, D., & Withers, J. (2019, Feb 25-Feb 27). A Study of the Adsorption of Collectors on Bastnaesite. In 2019 SME Annual Meeting and Exhibit, preprint.
• Zhang, J., & Feng, Q. (2016, Feb 21-Feb 24). Applying the mixture of mine tailings and fly ash as construction materials. In 2016 SME Annual Meeting and Exhibit, preprint.
• Zhang, J., & Zhang, W. (2016, Feb 21-Feb 24). An AFM Study of the Adsorption of Collector on Bornite. In 2016 SME Annual Meeting and Exhibit, preprint.
• Zhang, J., & Zhang, W. (2016, September). An AFM Study of the Adsorption of Ethyl Xanthate on Copper Sulfides. In XXVIII Internal Mineral Processing Congress.

Presentations

• Zhang, J. (2020, Jan 31, 2020). A study of the Chemicals’ Adsorption on Mineral Surface for Froth Flotation. Invited seminar. Clariant company (Tucson center): Clariant company.
• Zhang, J. (2020, Nov. 19, 2020). A study of the Chemicals’ Adsorption on Mineral Surface for Froth Flotation. 15th Chemical Dynamics Working Group. Ensco company (FL headquarter, virtual meeting): Ensco.
• Zhang, J. (2020, September 17-18, 2020). Study of the Chemicals’ Adsorption on Mineral Surface in Flotation. II International Congress of Mineral Processing PROCESSMIN 2020. Virtual Conference (Peru).