In Canada, spodumene (LiAlSi2O6) is the most common and widely explored among the lithium hard rocks. Its abundance and exploration potential have led to significant efforts in its study and development. It is noted that spodumene from Canada typically shows heterogeneous nature and simple mineralogy. The chemical components of spodumene pegmatites across different projects remain highly similar. The primary challenge in spodumene concentration lies in effectively separating it from sodic plagioclase (Na-feldspar) that shares similar crystal structure and has similar chemical composition with spodumene. This chapter presents lignosulphonate as depressant facilitating the separation of spodumene from Na-feldspar. The research employed surface chemistry, notably time-of-flight secondary ion mass spectrometry (ToF-SIMS) to explore the complexities of feldspar depression. The insights gleaned underscore potential challenges that may arise in industrial projects within Canada.

In the presence of Cu ions, a packed bed electrochemical reactor (PBER) was employed to deliberately avoid or induce galvanic coupling between pyrite and Cu‐activated sphalerite. The effect of galvanic interaction on Cu ions uptake and xanthate adsorption were investigated. Solution chemistry and surface chemistry studies (ethylenediaminetetraacetic acid extraction and time of flight secondary ion mass spectrometry) have observed that when sphalerite and pyrite were galvanically coupled, Cu ions migrated from the pyrite surface to the surface of the sphalerite. Along with the marked decrease in the adsorption of Cu ions on pyrite, xanthate adsorption on the minerals also dramatically dropped. The pseudo‐adsorption rate constant for the minerals in the mixed mode is only 0.0583 s‒1, much less than that in the decoupled mode, which is 0.1368 s ‒1. This testing program shows that the galvanic coupling of minerals contributes to more copper transfer and Cu ions preferentially adsorbed by sphalerite rather than pyrite. This affects the pyrite surface and causes it to become xanthate unflavoured.

Flotation separation of sphalerite from chalcopyrite is significantly affected by the oxidation of metal species on the surface of sphalerite, partially contributed by production of the reactive oxygen species hydrogen peroxide (H2O2) and hydroxyl radicals (OH center dot) if any during wet grinding of a complex sulphide ore. This research experimentally measures the production of H2O2 during grinding of a Cu/Zn ore from Mine Matagami (Canada) with different grinding time and in different grinding environments. Results reveal that H2O2 was formed spontaneously when the ore was ground in the ball mill. The amount of H2O2 generated increases with an increased pyrite load to the ball mill. Grinding with mild steel shows a lower measurable concentration of H2O2 in slurry relative to grinding with stainless steel balls. This appears to be in conflict with other researchers. It is found that Fe ions released from mild steel balls benefits the conversion from H2O2 to (OH center dot), but in the current H2O2 detection program hydroxyl radicals (OH center dot) could not be measured. Surface analysis of mineral grains from the mill discharge samples has identified an obvious correlation between H2O2 detected in the pulp and sphalerite surface oxidation. Lower pulp H2O2 concentrations possibly correspond to the conversion of H2O2 to OH center dot which may be linked to a more pronounced sphalerite surface oxidation.

Various studies have emphasized the importance of surface oxidation of sulfide minerals with regard to xanthate adsorption and their flotation response. However, the correlation between pyrite surface oxidation, xanthate adsorption and its flotation response has not been clearly established. The complexity lies in various intermediate sulfur oxidation products in different solution conditions. Thus, investigation of sulfur oxidation behavior is the key to understand pyrite oxidation. Ion chromatography (IC) and high performance liquid chromatography (HPLC) results showed an increase in the total amounts of occurring sulfur species with increasing slurry pH. Meanwhile, the ratio of S0/sulfur oxyanions was to become lower; X-ray Photoelectron Spectroscopy (XPS) identified the oxidized pyrite surface was rich in SO42− and FeOOH. Both the contact angle results and single mineral flotation data indicated that the more pyrite surface oxidized, the lower hydrophobicity and floatability were. Time-of-flight secondary ion mass spectroscopy (Tof-SIMS) was adopted to analyse xanthate adsorption on the surface of pyrite under conditions of either sufficient oxidation or on freshly polished surface which is assumed little oxidation. A significantly lower intensities of C4H9O and C4H9OCSS was found on the intensely oxidized pyrite surface, indicating xanthate adsorption had strong selectivity on FeS2 rather than FeOOH. The experimental results were further confirmed by theoretical calculation. The self-consistent charge density functional tight binding (SCC-DFTB) calculations indicated that the distances between the xanthate S atoms and surface Fe atoms of FeOOH were larger than the atomic radius of SFe. Essentially, the different electron configurations of their Fe atoms led to the selective adsorption of xanthate on FeOOH and FeS2 surfaces in terms of the coordination chemistry theory. This work provides valuable implications for understanding the correlation of surface oxidation, xanthate adsorption and its floatation behavior to mediate pyrite flotation.

Sodium silicate(s), also known as “water glass”, are one of the oldest and most widely used industrial chemicals. Its first use in Canadian operations can be traced back to around 1925, which coincided with early use of xanthates in mineral flotation. Silicate functions as a sulphide and non-sulphide gangue mineral dispersant, depressant and modifying reagent in grinding and flotation operations. It is believed that soluble sodium silicate promotes selectivity of value added sulphides against gangue minerals, resulting in both grade and recovery improvement. This paper seeks to link improved grade/recovery to the interaction characteristics of minerals and the sodium silicate. A systematic study was performed with individual mineral species, an artificially designed model ore and the feed ore from a copper flotation operation. The function of sodium silicate was evaluated in the context of colloidal chemistry and linked to mineral surface chemistry. Measurement of pulp rheology and mineral zeta potential identified that sodium silicate works as a dispersant. The dispersion is accomplished by increasing a mineral’s net surface charge, resulting in a change in slurry viscosity. Bench scale laboratory flotation tests suggest that better dispersion leads to a diminished interaction of chalcopyrite with gangue. The improved Cu grade and recovery then are likely in response to an increased accessibility to collector along with a linked increase in particle bubble attachment resulting in better separation efficiency. ToF-SIMS surface chemical analysis of the flotation samples found a higher proportion of sodium silicate on minerals from the flotation tailings relative to the concentrates. Moreover, attachment of sodium silicate appears to be mineral specific; the data indicates that sodium silicate favours the surface of gangue phases over the value sulphides.

When it comes to Pb-Zn ores with high amounts of pyrite, the major problem encountered is the low separation efficiency between galena and pyrite. By virtue of high dosage of lime and collector sodium diethyl dithiocarbamate (DDTC), pyrite and zinc minerals are depressed, allowing the galena to be floated. However, there have been significant conflicting reports on the flotation behavior of galena at high pH. In this context, correlation of the surface adsorption and oxidation with the floatability difference of galena and pyrite in high-alkaline lime systems would be a key issue for process optimization. Captive bubble contact angle measurements were performed on freshly polished mineral surfaces in situ exposed to lime solutions of varying pH as a function of immersion time. Furthermore, single mineral microflotation tests were conducted. Both tests indicated that the degree of hydrophobicity on the surfaces of galena and pyrite increased in the presence of DDTC at natural or mild pulp pH. While in a saturated lime solution, at pH 12.5, DDTC only worked for galena, but not for pyrite. Surface chemistry analysis by time-of flight secondary ion mass spectrometry (Tof-SIMS) confirmed the preference of DDTC on the galena surface at pH 12.5, which contributed to a merit recovery. Further important evidence through measurements of Tof-SIMS, ion chromatography, and highperformance liquid chromatography indicated that in high-alkaline lime systems, the merit floatability of galena could exclude the insignificant contribution of elemental sulfur (S-8) and was dominantly attributed by the strong adsorption of DDTC. In contrast, the poor flotation response of pyrite at high pH was due to the prevailing adsorption of CaOH+ species. This study provides an important surface chemistry evidence for a better understanding of the mechanism on the better selectivity in the galena-pyrite separation adopting high-alkaline lime systems.

This study focuses on the influence of ball mill medium and size on the properties of copper-zinc ore pulp and mineral surface by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and special designed grinding ball mill were applied. The pH, ORP (oxidation-reduction potential), conductivity and dissolved oxygen during grinding were monitored with redesigned chamber. The results show that, with grinding time prolonging, pH gradually increases, while dissolved oxygen content and ORP decrease rapidly. Smaller diameter of spherical grinding medium will result in greater consuming rate of the dissolved oxygen content, whereas lower ORP and pulp ions concentration. Surface chemistry analysis TOF-SIMS was performed on mill discharged sphalerite. It demonstrates that the formation of iron oxide and hydroxide species on sphalerite surface, as well as different types and different sizes of grinding medium can affect the mineral surface. Compared with spherical grinding diameter of 2.54 cm, diameter of 1.27 cm could supply more iron ions for pulp and improve electricity reactions during grinding, thus leading to the formation of more iron oxide and hydroxide species on sphalerite surface and lower adsorption of cupric ions (Cu2+). The same is also true for mild steel compared with stainless steel. From above, the pulp and sphalerite surface chemistry are decided by the types and sizes of grinding medium.

Gold losses related to carbonaceous matter (CM) during processing are a significant problem in the gold processing industry. Inherent CM in gold ores can behave similarly to activated carbon in its ability to adsorb gold cyanide. This phenomenon is termed preg-robbing as the surface adsorbed gold cannot, for the most part, be recovered. Research has identified that gold adsorption by inherent CM is linked to the specific surface area, pore structure, degree of C disorder and surface functional groups. One of the strategies to inhibit CM preg-robbing prior to leaching is a chemical oxidation; a process linked to modification of the surface functionality. In this study, the variability in gold cyanide adsorption due to oxidation with different reagents has been investigated. Variability in gold cyanide adsorption by CM is examined in relation to structural and surface modifications using TOF-SIMS, XPS and Raman spectroscopy.

Changes in mineral surface properties during grinding play a key role in flotation performance. Time of flight secondary mass spectrometry (ToF-SIMS) surface chemical analytical studies have shown that flotation separation of sphalerite from chalcopyrite is significantly affected by the oxidation of metal species on the surface of sphalerite. The intensity of iron oxyhydroxyl species on the surface of sphalerite has a positive correlation with poor recovery of sphalerite. Given the link between the presence of oxide species on the surface of sphalerite and a lower recovery during copper flotation, a laboratory study was initiated to evaluate the potential for sphalerite surface oxidation control and improving recovery through grinding. For the investigation, a ball mill that allowed for monitoring pulp chemistry during grinding was utilized to study the impact of grinding conditions on selective flotation of sphalerite. ToF-SIMS was used to identify and measure the variability in sphalerite surface species as a result of the different test parameters. Variable mill parameters include two types of grinding media, aeration conditions, addition of FeSO4, and altering the pyrite content in the feed ore. ToF-SIMS analyses of mill discharge samples identified higher intensities of iron oxyhydroxyl species on sphalerite surface subsequent to grinding with mild steel balls, in condition of aeration, use of FeSO4, and by increasing the pyrite content of the feed ore. The higher adsorption of iron oxyhydroxyl species on the surface of sphalerite should be consistent with the lower recovery. To verify this, bench-scale flotation tests in the presence and absence of FeSO4 were performed; results correlated iron oxyhydroxyl species with the poor sphalerite recovery. Copyright (c) 2017 John Wiley & Sons, Ltd.

A modified xanthate compound similar to xanthogen formates, S-benzoyl O-isobutyl xanthate (BIBX), was designed by introducing a carbonyl and a benzyl group into the xanthate structure. The preparation, recovery performance, and mechanism of adsorption of this compound to chalcopyrite is discussed. BIBX was synthesized using a one-pot approach with superior efficiency, which has important commercial implications. BIBXs performance in the recovery of and mechanism of adsorption to chalcopyrite was investigated via flotation tests, adsorption quantity measurements, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. The results show that BIBX displays a substantially stronger collecting ability toward chalcopyrite than sodium isobutyl xanthate and O-isopropyl-N-ethylthionocarbamate. Moreover, BIBX displays superior selectivity for chalcopyrite compared to pyrite. The adsorption data indicate that BIBX can be applied under slightly acidic or alkaline conditions. BIBX behaves like a bidentate ligand, bonding with the chalcopyrite copper through the thiol sulfur and carbonyl oxygen atoms. These findings are supported by FTIR and XPS data. DFT calculations predict two distinct adsorption geometries, one with one Cu atom to form a six-membered ring complex and another with two Cu atoms to form an "irregular pentagon"-shaped complex.

Plant and laboratory test work was performed in order to optimize a copper/zinc flotation separation circuit at Matagami concentrator, Canada. The testing identified a significant difference between the laboratory testing and the plant flotation, particularly for the sphalerite recovery in the rougher copper concentrate. Tests indicate that sphalerite recovery of the flotation concentrate in the laboratory testing was significantly higher than in the plant. The ToF-SIMS surface analysis identifies surface species responsible for the discrepancy in Zn recovery. It shows that sphalerite flotation is in response to the collector attachment and a significant enrichment of Cu on the surface of sphalerite grains. A comparative surface chemical analysis was performed on both sphalerite and chalcopyrite grains from the plant flotation and laboratory testing in order to identify surface species variability between the two testing. Two significant observations were revealed. First, there is considerably more hydrophilic iron oxyhydroxide on sphalerite surface from the plant flotation sample relative to those from the lab testing. The secondary coating likely completely or partially passivates sphalerite surfaces, reducing Cu enrichment and hence sphalerite floatability. Secondly, comparing the surface chemistry on sphalerite and chalcopyrite, the hydrophilic iron oxyhydroxide species have preference for the sphalerite grains relative to chalcopyrite. Despite numerous studies on the effect of galvanic coupling during grinding, there is limited documented evidence on the effect of the milling environment on the flotation and plant operations. This observation suggests that interaction between sulphide minerals and grinding media have a significant influence on subsequent flotation. This paper discusses the results of a detailed surface chemical evaluation of sphalerite grains from both the plant and laboratory testing in the context of grinding environments and pulp chemistry.

The flotation separation is the general method to recover molybdenite from a concentration containing molybdenite and bismuthinite, although the whole circuit could be long and complicated. In this paper, a novel selective electro-oxidation of molybdenite process has been introduced and systematically investigated for bismuthinite purification. It was found that Mo could be selectively separated by the electro-oxidation method under the conditions of pH not less than 9.0 and the applied potential at between 3.0V and 4.0V, by this circumstance Bi was hard to extract. The effects of NaCl concentration, liquid/solid ratio and stirring speed on electro-oxidation leaching were investigated. Optimum leaching conditions were found as follows: operated at room temperature, leaching time=2.5h, NaCl concentration=4mol/L, pH=9–10, applied potential=3.4V, liquid/solid ratio=30mL/g, stirring speed=400rpm. Under these conditions, Mo extraction yield was obtained at 98.4% and 99.3% of Bi remained in the residue. The chlorine evolution reaction at the anode which was effected by leaching pH was studied by linear scan voltammetry. Mechanism of electro-oxidation leaching of Mo was studied by cyclic voltammetry. Furthermore, the mass transfer of Mo from leachate to organic phase was introduced, and the two phase transfer could obtain as high as 99.6%.

The influence of lead nitrate on rare earth flotation in the presence of hydroxamates as collectors has been investigated by a combination of micro-flotation tests and time of flight secondary ion mass spectrometry (ToF-SIMS) surface chemical analysis. Micro-flotation tests identified a link between lead nitrate dose and an improved grade of REE minerals for concentrates. The testing also identified differences in the flotation behaviour of light rare earth (LREEs, La or Ce bearing minerals) and Y and Zr bearing minerals. TOF-SIMS analyses evaluated the variability in surface components on undifferentiated REE grains from the concentrates and tails samples in response to the varied lead nitrate dosing in micro-flotation tests. The surface analyses showed that both the REE grains and gangue phases reporting to the concentrate have higher relative surface proportions of both Pb and collectors as compared to those reporting to the tails. It is noted that the lead does not appear to be associated with an increase in collector adsorption, so the grade of REE can go up is not by selective adsorption of collectors. The significantly higher intensity of Pb species identified on the surface of the concentrate would suggest that lead addition can actually reverse the surface charge making it efficient for collectors to adsorb onto surfaces that they could not easily close to. It is also possible PbOH+ potentially acting as a point activator. (C) 2014 Elsevier Ltd. All rights reserved.

The Nechalacho project is the most advanced large heavy rare earth elements (HREE) project outside of China. Open circuit and locked cycle flotation tests along with pilot plant testing of rare earth elements (REE) concentration from the host rocks are accomplished with collectors of alkyl phosphates and the modifier of citric acid. In this study, the function of citric acid in the separation of rare metals against silicates is investigated by a combination of micro-flotation tests and time of flight secondary ion mass spectrometry (ToF-SIMS) surface chemical analysis. It was observed that there was little effect of citric acid on the REE recovery in the micro-flotation tests conditioned with de-ionized water (DIW). To evaluate the flotation response with excess secondary ions in the pulp, micro-flotation tests were performed to look at changes in recovery as a result of adding Al ions and the subsequent presence of citric acid. The results from three micro-flotation tests (DIW, DIW with the addition of 100 mg/L Al and DIW + 100 mg/L Al and 500 g/t citric acid) revealed that the addition of Al ions led to a decrease of REE grade, a lower REE minerals recovery and/or an unexpected promotion of silicates to the concentrate. Citric acid reduced the negative effect generated by the Al ions in the flotation, which was shown by an improvement in REE grade. ToF-SIMS surface analysis of undifferentiated grains from the tests with and without citric acid revealed that grains reporting to the concentrate are doing so in response to collector attachment in combination with having more secondary Al on their surface. Citric acid may partially form aqueous soluble metal-ligand complexes resulting in less Al ions on the grains surface, which were rejected to the tailings. Citric acid also may form chelation competing for adsorption on gangue minerals, resulting in a diminished effectiveness of the activation site. (C) 2015 Elsevier Ltd. All rights reserved.

In this paper, a Gemini surfactant, ethane-1,2-bis(dimethyl-dodecyl-ammonium bromide) (EBAB), was introduced as a collector for reverse cationic flotation separation of quartz from magnetite, and its adsorption mechanisms on the two minerals and air/water interface were also investigated by FTIR spectra, zeta potential, density functional theory (DFT) calculation and surface tension. The flotation results showed that EBAB presented stronger collecting power than the conventional monomeric surfactant dodecylammonium chloride (DAC) and superior selectivity for quartz against magnetite. The results of FTIR spectra and zeta potential measurements demonstrated that the interaction of EBAB with quartz and magnetite was mainly through electrostatic attraction, which was further confirmed by DFT calculation. EBAB was preferred to adsorb on the negatively charged surface of quartz, increasing its zeta potentials and improving its hydrophobicity. Adsorption of EBAB at the quartz/water interface could be divided into four stages as the concentration of EBAB was increased in solution. At low concentrations, adsorption was controlled primarily by electrostatic interactions, but when the zeta potential of quartz was reversed from negative to positive, hydrophobic chain interactions controlled the adsorption process. EBAB's unique properties, such as high positive grouping Mulliken charge of -CH2N+(CH3)(2)(CH2)(2)(CH3)N+CH2-, and strong "surface activity" at the air-water interface, made it be a superior cationic collector for reverse flotation desilication from iron ores. (C) 2014 Elsevier B.V. All rights reserved.

The application of hydroxamic acid as flotation collectors is fast becoming of significant interest for the selective flotation of oxide minerals along with upgrading oxidised based metal ores and minerals. In the hydroxamate molecule, both O and N atoms in the -CONHOH group are identified as coordination atoms in many complexes and their characteristic structure determines the strength of the chelation complex between the hydroxamate and metal ion. The chelating performance of hydroxamates with transition metals including Cu, Ni, Zn, Fe, Cr, Mn and Co, the alkaline-earth metals (Be, Ca) and heavy metal (Pb) has been studied. Cytec has developed and patented a range of alkyl hydroxamates as flotation collectors for oxidised base metal sulphides, metal oxide minerals and precious metals. This paper introduces two new structures of hydroxamate collectors (Cyclohexyl and 4-tert-butylbenzoyl hydroxamates) and evaluates their characteristics relative to alkyl and benzoyl hydroxamates. Laboratory small-scale flotation tests were conducted with ilmenite and wolframite. The use of 4-tert-butyl benzoyl hydroxamate resulted in a best flotation performance for ilmenite. A relatively low cyclohexyl hydroxamate dosage was required in the flotation of wolframite to obtain comparable results to the alkyl and benzoyl hydroxamates. It is also shown a significantly improved flotation performance with 4-tertbutyl benzoyl hydroxamate in the flotation of ilmenite plant ore in comparison to the oleic acid or fatty acid collectors typically used for ilmenite flotation.

In this paper, an amino-trisiloxane Gemini cationic surfactant, butane-1,4-bis(dimethyl-(3-(3-aminopropyl trisiloxane-3-yl)-propyl)-ammonium bromide) (BBAB) was prepared, and its flotation potential was assessed on kaolinite, pyrophyllite and illite minerals. The flotation results showed that changes to the pulp pH did not significantly influence BBAB's collecting power in floating three aluminosilicate minerals. In addition, BBAB was a stronger collector than the conventional monomeric surfactant dedecyl trimethylammonium bromide (DTAB) or dodecylamine (DDA). The results of FTIR spectra, zeta potential measurements and density functional theory (DFT) calculations indicated that the interaction of BBAB with the three aluminosilicates was mainly through electrostatic attraction. BBAB's unique properties, such as high positive grouping Mulliken charge of -CH2N+(CH3)(2)(CH2)(4)(CH3)(2)N+CH2-, and "parachute" shape structure of [(CH3)(3)SiO](2)SiCH3, resulted in superior collecting powers for the aluminosilicate minerals. (C) 2013 Elsevier Ltd. All rights reserved.

The Thor lake deposit is a world class resource of rare earth (REE) metals and minerals in Canada. Development work to optimize a REE mineral recovery process flow sheet is underway, however, given the ore mineralogy; the developed reagent scheme is relatively complex. As part of a research project, micro-flotation tests were conducted on a feed sample in order to examine factors affecting stream partitioning. SEM–EDX was performed to evaluate variability in grain composition between streams (concentrate and tails) and TOF-SIMS surface analysis was used to determine statistically significant differences in surface species particularly related to potential activation (or depression) of the examined mineral phases. SEM–EDX analysis reveal that the concentrate has a significantly higher proportion of REE bearing grains (carbonates and phosphates) relative to the tail (almost none were identified). Spectral fingerprinting by TOF-SIMS has allowed for the identification of all reagent species investigated. Reagent signal intensity discrimination on test stream mineral surfaces was observed by the TOF-SIMS analysis using reagents at plant concentration levels. TOF-SIMS analysis confirmed that REE bearing grains reporting to the concentrate are doing so in response to collector attachment whereas grains reporting to the tail are doing so in response to a lack of collector and/or in combination with the presence of the depressant. The surface analysis of gangue phases reveal a similar reagent discrimination; the signal intensity of collector species was significantly higher on the concentrate samples relative to the tails while depressant species were significantly enriched on the surface of the gangue phases in the tail samples. A detailed evaluation of the surface species representing the various reagents used in flotation scheme revealed a distinct competitive relationship between two of the reagents. The surface analysis identified that when used in concurrently, there appears to be a negative feedback resulting in a significant reduction in loading for several of the collectors on grains reporting to the concentrate. An evaluation of the effect of reagents on REE mineral in pilot plant is currently under way.

The separation of rhenium from molybdenum in aqueous solution has always been a problem in hydrometallurgy. The separation of rhenium from the electro-oxidation leachate of molybdenite and its mechanism were investigated. The results show that pH of the leachate significantly affects adsorption rate compared with other experimental parameters. When temperature is 30 °C, pH=8, and adsorbing time is 1 h, adsorption rates of rhenium and molybdenum are 93.46% and 3.57%, respectively, and separation factor of D301 resin for rhenium and molybdenum is 169.56. In addition, the separation factor is higher when the initial molybdenum concentration in model solution is increased. The saturated adsorption capacity of D301 resin for molybdenum and rhenium calculated based on simulated results are 4.263 3 mmol/g and 4.235 5 mmol/g, respectively. D301 resin is an effective separation material of rhenium from electric-oxidation leachate of molybdenite. The adsorption kinetics results also show that the adsorption of rhenium is easier than that of molybdenum, and the adsorption process of D301 for rhenium and molybdenum may be controlled by liquid film diffusion.

Gemini quaternary ammonium salt surfactants, butane-α, ω-bis(dimethyl dodeculammonium bromide) (BDDA) and ethane-α, β-bis(dimethyl dodeculammonium bromide) (EDDA) were adopted to comparatively study the flotation behaviors of kaolinite, pyrophyllite and illite. It was found that three silicate minerals all exhibited good floatability with Gemini cationic surfactants as collectors over a wide pH range, while BDDA showed a stronger collecting power than EDDA. FTIR spectra and zeta potential analysis indicated that the mechanism of adsorption of Gemini collector molecules on three silicate minerals surfaces was almost identical for the electronic attraction and hydrogen bonds effect. The theoretically obtained results of density functional theory (DFT) at B3LYP/6-31G (d) level demonstrated the stronger collecting power of BDDA presented in the floatation test and zeta potential measurement.