Floatability Of Quartz Research Articles

Investigation of the effect and mechanism on the flotation performance of alkylglycine-based collectors by acyl group

The structure difference of the flotation reagent has a significant influence on its flotation performance. In this work, sodium N-lauroyl glycinate (SNG) was synthesized by introducing an acyl group into sodium N-dodecylglycinate (SN), and was using the collector in the oxide ores flotation. Properties of these two collectors were compared, and the effects behavior and mechanism of introducing the acyl group on the flotation performance of alkylglycine-based collectors to the zinc oxide minerals were systematically investigated. Flotation results proved that the introduction of C = O group into SN barely affected the floatability of smithsonite, hemimorphite and calcite, while the floatability of quartz was greatly reduced. Contact angle tests, surface tension tests, and froth collapse measurements indicated that the introduction of the acyl group into SN could selectively weaken its ability to improve the hydrophobicity of mineral surfaces, reduce its surface tension, adsorption capacity and intensity on the mineral surface, and the froth stability, thereby enhancing its selectivity, consistent with the flotation results. Fourier transform infrared spectroscopy (FTIR) analyses and density functional theory (DFT) calculations revealed that the introduction of the acyl group could increase the cross-sectional area and reduce the charge of the SNG polar groups to selectively weaken the adsorption interaction, particularly by significantly reducing the electrostatic adsorption between SNS and quartz surfaces. These also confirm that SNG is a promising highly selective collector for the flotation separation of zinc oxide minerals.

Desilication and purification of phosphogypsum waste by flotation using a photosensitive collector

Phosphogypsum (PG) is the main by-product of wet phosphoric acid production and has seriously polluted the environment. In this study, PG was purified by reverse flotation using a photosensitive azobenzene surfactant (PASF). After reverse flotation, the content of gypsum in PG increased from 89.16 % to 93.32 %, the whiteness of PG increased from 25.62 % to 60.9 %, and the content of quartz decreased from 4.87 % to 2.12 %. The Zeta potential of quartz and gypsum became positive after being treated with PASF, indicating that PASF enhanced the floatability of quartz and gypsum. The results of FTIR and XPS indicated that there were both electrostatic attraction and hydrogen bonding between PASF and quartz. Density functional theory (DFT) calculations indicated that the adsorption of PASF on the quartz surface was more stable than on the gypsum surface. Upon exposure to UV irradiation, the molecular structure of PASF was transformed from trans to cis. Meanwhile, the adsorption amount of PASF on the quartz surface was decreased and the rigidity of the corresponding adsorbed layer was increased. This work provides a method to purify PG waste, which is important for the comprehensive utilization of PG.

Starch vs. tannin as biodegradable reagents for ultrafine hematite depression

Enrichment of ultrafine liberated valuable minerals from their associated gangue phases is one of the emerging investigation topics within mineral processing and recycling. Using green flotation reagents and turning processes into eco-friendly systems is also one of the challenges in the green transition of ore beneficiation plants. Starch and Tanin as biodegradable depressants for hematite depression have been commercially used in various iron ore processing plants. However, their depression effects on ultrafine particles were not systemically assessed and compared. To fill this gap, this investigation examined the effects of starch, tannin, their mixtures (different ratios), and their different conditioning sequence on the floatability of ultrafine quartz and hematite (− 15 µm). Since the macromolecular polymer of these biodegradable depressants can bind particles together and flocculate them, turbidity analyses were used to assess their optimum ratio for hematite depression without affecting quartz floatability. Turbidity analyses provided a mixture of tannin and starch might enhance the flotation separation of quartz from hematite. Starch could flocculate ultrafine hematite particles, while tannin could disperse ultrafine quartz particles. Floatability experiments indicated that starch had the highest performance in hematite depression (lowest effect on quartz particles) compared to other conditions. Surface analyses (zeta potential and FTIR) proved floatability outcomes and highlighted starch had stronger adsorption on the hematite surface than tannin.

Green hematite depression for reverse selective flotation separation from quartz by locust bean gum

Reverse cationic flotation is currently the main processing technique for upgrading fine hematite from silicates. Flotation is known as an efficient method of mineral enrichment that deals with possibly hazardous chemicals. Thus, using eco-friendly flotation reagents for such a process is an emerging need for sustainable development and green transition. As an innovative approach, this investigation explored the potential of locust bean gum (LBG) as a biodegradable depressant for the selective separation of fine hematite from quartz through reverse cationic flotation. Various flotation conditions (micro and batch flotation) were conducted, and the mechanisms of LBG adsorption have been examined by different analyses (contact angle measurement, surface adsorption, zeta potential measurements, and FT-IR analysis). The micro flotation outcome indicated that the LBG could selectively depress hematite particles with negligible effect on quartz floatability. Flotation of mixed minerals (hematite and quartz mixture in various ratios) indicated that LGB could enhance separation efficiency (hematite recovery > 88%). Outcomes of the surface wettability indicated that even in the presence of the collector (dodecylamine), LBG decreased the hematite work of adhesion and had a slight effect on quartz. The LBG adsorbed selectively by hydrogen bonding on the surface of hematite based on various surface analyses.

Mechanism of ultrasonic cavitation to improve the effect of siderite on quartz flotation

In order to effectively eliminate the effect of fine carbonate minerals on quartz flotation, the influence of fine siderite on quartz flotation was studied as well as the mechanism or role of ultrasonic treatment in the process. The results of adsorption capacity measurement and flotation solution chemical calculation show that fine siderite and its dissolved components have a great influence on the collector consumption and the surface properties of quartz. In addition, SEM, EDS and XPS analysis were used to study the surface morphology and chemical environment changes of quartz with and without ultrasonic treatment. The results of flotation test show that the recovery of quartz increase from 38.79% to 58.38% under the condition that ultrasonic time was 0.5 min and ultrasonic power was 200 W. The mechanical effect caused by ultrasonic cavitation can clean the quartz surface to a certain extent and increase its active sites, thus improving the floatability of quartz.

Collector mixtures and their synergistic effect on quartz floatability

Sinergy is the interaction of two or more agents to produce a combined effect greater than the sum of their separate effects. Etherdiamine yields superior results for quartz floatability in a Hallimond tube and higher selectivity in the reverse bench scale cationic flotation of an iron ore, when compared to ethermonoamine. Blending these collectors yields better results than each one used individually characterizing a synergistic effect. This work evaluated the effects of the collectors ethermonoamine, etherdiamine and the mixture of these at the ratio 1:1 on the flotation of the quartz through the microflotation and bench flotation tests with a typical Brazilian iron ore. The results demonstrated the occurrence of synergistic effects in tests performed at concentrations of 1 and 3 mg/L and pH 10.5, in the absence of a depressant. In the presence of a depressant, the synergy was not observed under the same tested conditions, due to the collector-depressant interaction. On other hand, the bench flotation tests indicated the occurrence of synergy regarding silica content in the concentrate while an additive effect was observed for the iron recovery and Selectivity Index index demonstrating that a feasibility of using collector mixtures in this process, was not clearly achieved on the tested ratio 1:1.

Effective flotation separation of malachite from quartz with a selective collector: Collection ability, separation performance and adsorption mechanism

In this study, we focused on the collecting features and sorption mechanism of stearyl diethanolamine (SDA) used as a novel collector towards the surfaces of quartz and malachite, to recover efficiently malachite from quartz. The flotation results demonstrated that DSA displayed an excellent collection performance for quartz but not for malachite. At pH 6.50, with 8 mg/L SDA, effectively recovering malachite from quartz was achieved by reverse flotation, in which 92.71 % of malachite was recovered and 91.91 % of quartz was removed, coupled with a high separation efficiency (SE) of 84.63 % and a high concentrate Cu grade of 52.52 %. Surface wettability studies suggested that SDA significantly improved the surface hydrophobicity of quartz but not malachite, as evidenced by the significantly increased contact angle of quartz (from 24.16° to 97.16°), which resulted in the excellent floatability of quartz. Adsorption amount detection results revealed that the adsorption density of SDA on quartz was much higher than that on malachite, namely 0.065 mg/g for quartz and 0.0049 mg/g for malachite, which enhanced the hydrophobicity of quartz. Zeta potential characterization and FTIR detection evidenced that apart from the strong electrostatic attraction interaction of the positively charged SDA+ with the quartz surface with negative charge, the strong adsorption of SDA onto quartz also depended much on the hydrogen bonding interaction between quartz’s Si-OH groups and SDA’s hydroxyl groups. Therefore, SDA can be regarded as a highly selective quartz collector to realize the effective recovery of malachite.

Study on the influence of particle size on the flotation separation of kaolinite and quartz

The influences of particle size on the flotation separation of kaolinite and quartz was explored by flotation tests of full-size and various sizes, zeta potential analysis. The flotation separation effects of kaolinite and quartz mixed minerals under different conditions were analyzed by calculating the characteristic parameters such as K, R ∞ , Km, SI and SE. Results show that in the sodium oleate scenario, kaolinite has better floatability under neutral conditions, while quartz has better floatability at pH 12. Ca 2+ has little effect on the floatability of kaolinite but it does inhibit the floatability of quartz under acid and weak alkali conditions. As well it can improve the floatability of quartz at a pH 12. In the two mineral flotation separation tests, reverse flotation had better selectivity for coarse-grained minerals. The maximum separation efficiency of the mixed ore with a particle size of 0.125–0.075 mm was 71.88%, the recovery of kaolinite in the concentrate was 84.97%, and the recovery of quartz amounted to 13.10%. It is of great significance to the research on the flotation separation of kaolinite and the high resource utilization of kaolinite. • 0.250–0.030 mm can be separated through positive and reverse flotation. • −0.030 mm fine kaolinite and quartz can't be separated by sodium oleate flotation. • When pH is less than 8, Ca 2+ is conducive to positive flotation separation. • Conforms the first kinetic model, reverse flotation has high separation efficiency.

Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach

Grinding is the most energy-intensive step in mineral beneficiation processes. The use of grinding aids (GAs) could be an innovative solution to reduce the high energy consumption associated with size reduction. Surprisingly, little is known about the effects of GAs on downstream mineral beneficiation processes, such as flotation separation. The use of ecofriendly GAs such as polysaccharide-based materials would help multiply the reduction of environmental issues in mineral processing plants. As a practical approach, this work explored the effects of a novel polysaccharide-based grinding aid (PGA) on magnetite's grinding and its reverse flotation. Batch grinding tests indicated that PGA improved grinding performance by reducing energy consumption, narrowing particle size distribution of products, and increasing their surface area compared to grinding without PGA. Flotation tests on pure samples illustrated that PGA has beneficial effects on magnetite depression (with negligible effect on quartz floatability) through reverse flotation separation. Flotation of the artificial mixture ground sample in the presence of PGA confirmed the benefits, giving a maximum Fe recovery and grade of 84.4 and 62.5%, respectively. In the absence of starch (depressant), PGA resulted in a separation efficiency of 56.1% compared to 43.7% without PGA. The PGA adsorption mechanism was mainly via physical interaction based on UV–vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR), and stability analyses. In general, the feasibility of using PGA, a natural green polymer, was beneficial for both grinding and reverse flotation separation performance.

Effect of Ether Mono Amine Collector on the Cationic Flotation of Micaceous Minerals—A Comparative Study

Micaceous minerals, known as layer silicates, are counted mostly as the gangue minerals associated with valuable minerals, especially iron oxides. They mainly reject through the reverse flotation process using the cationic collectors, e.g., ether amines, to improve process sustainability. Although ether amines have been applied for floating the wide range of silicates, few investigations explored their adsorption behaviors on the micaceous minerals. In this study, flotation of phlogopite, biotite, and quartz (for comparison purposes) in the presence of Flotigam®EDA (EDA) (commercial ether monoamine collector), at pH 10 was investigated through the single mineral micro–flotation experiments. Adsorption behaviors were explored by the contact angle, residual surface tension measurements, and zeta potential analyses. Micro–flotation outcomes indicated that the quartz floatability was more than phlogopite and biotite. In the presence of 30 mg/dm3 EDA, their recoveries were 97.1, 46.3, and 63.8%, respectively. Increasing EDA concentration made a substantial increase in micaceous minerals’ floatability. Adsorption assessments confirmed that increasing the EDA concentration resulted in higher adsorption of EDA onto the surface of micaceous minerals than the quartz (all by physical adsorption). Such a behavior could be related to the nature of micaceous minerals, including their layer structure and low hardness.

Citric acid inhibits the floatability of quartz in Mg<sup>2+</sup> system

Citric acid inhibits the floatability of quartz in Mg<sup>2+</sup> system

Study on regulators of purifying magnesite ore by cationic reverse flotation

The floatability of magnesite, dolomite and quartz is a major factor affecting the removal of silicon and calcium from magnesite ore. The effect of the regulators sodium hexametaphosphate (SH), sodium silicate (SS), trisodium phosphate (TP), tannic acid (TN) and monoammonium oxalate (OA) on the floatability of magnesite, dolomite, and quartz under the ether amine (EAH) system was studied. The results show that the five regulators have relatively little influence on the floatability of quartz and magnesite. Dolomite can be activated when the dosage of SH is less than 40 mg/L; however, dolomite can be inhibited when the SH dosage is greater than 40 mg/L. The other four regulators have inhibitory effects on dolomite, and TN and TP have strong inhibitory effects on dolomite. Under the conditions of optimum grinding fineness, pH and collector dosage, a recovery of approximately 70% and a concentrate with a grade of over 47% were obtained by three stages of reverse flotation using sodium hexametaphosphate and water glass as regulators and Haicheng magnesite ore with an SiO2 content of 2.38% and a CaO content of 0.75%. Potentiometric measurements and infrared spectroscopy analysis show that physical adsorption occurs between the three minerals and collectors, while the interaction of magnesite and dolomite with SH and SS involves both physical adsorption and chemical adsorption.

New perspectives in iron ore flotation: Use of collector reagents without depressants in reverse cationic flotation of quartz

The reverse flotation of the iron ore with etheramine collector is significantly impacted when the iron-bearing silicates and the kaolinite are present in the silicates gangue mineral complex. This paper aims to propose a new amidoamine collector N-[3-(Dimethylamino)propyl]dodecanamide for iron ore reverse flotation with a potential of removing the iron oxides depressant. The contact angle and electrophoretic mobility measurements as well as the flotation experiments were performed on the pure quartz, kaolinite and hematite samples to compare its effect with the etheramine which is widely used as collector in reverse flotation of iron ores. Infrared spectroscopy was performed to study the adsorption of the amidoamine collector on the surface of the minerals studied.Amidoamine collector showed a significant selectivity towards quartz while the flotation of hematite and kaolinite were inhibited at pH 10 without the presence of a depressor. A total floatability of quartz was explained by increased contact angle from 10° to about 50° without impacting significantly the contact angle measured on the hematite (9.4° to 17°). Surface hindrance effect caused by the structure of the N-[3-(Dimethylamino)propyl]dodecanamide collector on the hematite surface is the most suitable hypothesis concerning the high selectivity regarding the iron ore reverse flotation process.

Tannin: An eco-friendly depressant for the green flotation separation of hematite from quartz

Reverse cationic flotation is the most known beneficiation method for the separation of fine hematite particles from silicates. In this process, the depression of the hematite surface is an essential factor. Thus, the development of environmentally friendly depressants plays a critical role. Tannin (TA) as a natural and eco-friendly organicreagent has not yet been considered for such a purpose. Through the reverse cationic flotation, the depression effect of TA was investigated by single and mixture of minerals. Micro-flotation tests and wettability analysis based on contact angle measurements by the captive bubble method (CBM) were conducted. The surface adsorption mechanism of TA on the hematite and quartz was explored through turbidity, zeta-potential measurements, surface adsorption tests, and Fourier transform infrared (FT-IR) analyses. The micro-flotation results indicated that TA could selectively depress more than 90% of hematite, while its effect on quartz floatability was negligible (<8% depressing). Surface wettability analysis demonstrated that TA in the presence of 30 mg/L collector could significantly increase the work of adhesion of hematite from 135.5 to 143.1 erg/cm2, whereas it increased the work of adhesion of quartz from 117.1 to 120.7 erg/cm2. Surface adsorption analysis depicted that in the presence of 100 mg/L TA, the adsorption amount of TA on the hematite surface was 0.99 mg/g, while this amount for quartz was 0.17 mg/g (around 6 times lower than hematite). Turbidity measurements, applied to clarify the aggregation – dispersion behavior of pure minerals in the TA presence, showed that TA had a dispersion effect on the quartz particles, whereas TA caused hematite aggregation. Surface analyses proved that TA selective adsorption occurred on the hematite surface mainly by chemisorption. In contrast, poor physical adsorption was the main interaction between TA and the quartz surface.

Synergistic Effect of Binary Surfactant Mixtures in Two-Phase and Three-Phase Systems.

Cationic alkyltrimethylammonium bromides (CnTAB, with n = 8, 12, 16, 18) and their mixtures with n-octanol as a nonionic surfactant were chosen as a model system to study the synergistic effect on foamability (two-phase system) and floatability (three-phase system) of quartz in the presence of binary mixtures of ionic/nonionic surfactants. The foam height of one-component solutions and binary mixtures and floatability of quartz particles were characterized as a function of the surfactant concentration and the number of carbons (n) in the alkyl chain of CnTAB. The experimental results of foamability and floatability measurements in one-component and mixed solutions revealed the synergistic effect, causing a significant enhancement in the foam height and recovery of quartz. In the presence of n-octanol, the height of foam increased remarkably for all CnTAB solutions studied, and this effect, whose magnitude depended on the CnTAB hydrophobic tail length, could not be justified by a simple increase in total surfactant concentration. A similar picture was obtained in the case of flotation response. The mechanism of synergistic effect observed in mixed CnTAB/n-octanol solutions was proposed. The discussion was supported by molecular dynamics simulations, and the probable mechanism responsible for synergism was discussed. In addition, an analysis allowing accurate determination of the concentration regimes, where the synergistic effect can be expected, was given. It was shown that for the two-phase system, the n-octanol molecule preadsorption at the liquid/gas interface causes an increase in CnTAB adsorption coverage over the level expected from its equilibrium value in the one-component solution. In the case of the three-phase system, the synergistic effect was related to the ionic surfactants serving as an anchor layer for n-octanol, which, in water/n-octanol solution (one-component system), do not adsorb on the surface of quartz.

A Study on the Electric Surface Potential and Hydrophobicity of Quartz Particles in the Presence of Hexyl Amine Cellulose Nanocrystals and Their Correlation to Flotation

In this work, the study of hexyl amine cellulose nanocrystal (HAC) as a renewable and environmentally-friendly reagent for the flotation of quartz (QRZ) is expanded with a focus on the changes of electrical states at the solid-liquid interface, the range of solid-gas interactions, and their impact on flotation operations under a turbulent regime. Furthermore, particle-bubble attachment probabilities were measured with the recently engineered automated contact timer apparatus (ACTA), a versatile technique used to deduce the wettability of microparticles and potentially predict their floatability. Therefore, the findings of the ACTA proved that, with sufficiently hydrophobic QRZ (i.e., HAC concentration ≥ 0.667 mgHAC/m2QRZ), stable particle-bubble attachments occur at particle-bubble distances in the range of tens of micrometres. The distances for the successful attachment of HAC-coated QRZ particles exceed the range of interactions reported in literature so far and imply the existence of structural or hydrodynamic phenomena acting between particle and bubble surfaces. The occurrence of so-called non-compressive particle-bubble attachments is shown to correlate with a significant increase in the floatability of QRZ, where recoveries up to 90% were obtained. Based on the experimental results, some insights on the nature of the long-range interactions responsible for the particle-bubble attachment of hydrophobic particles are provided.

Evaluation of hematite and quartz flotation kinetics using surfactant produced by Rhodococcus erythropolis as bioreagent

Abstract The use of biosurfactants as reagents represents a promising alternative to the conventional surfactants used in the mineral industry because they may present low toxicity and high biodegradability. Therefore, this research studied the hematite and quartz flotation kinetics using surfactant produced by Rhodococcus erythropolis as bioreagent. The flotation kinetics of both minerals were evaluated under established conditions: biosurfactant concentration of 10 mg/L and solution pH of 3. The maximum floatability values were of 99.98% and 17.53% for hematite and quartz, respectively, after 2 minutes of flotation. Finally, the kinetics study indicated that the experimental data of hematite floatability was better fitted to both the first and non-integral order kinetics, while the experimental data of quartz floatability was better fitted to the non-integral order kinetic.

Depressants in nanoemulsion systems applied to quartz and hematite microflotation

Nanoemulsion systems were investigated in the microflotation of quartz and hematite. Four different depressants were used: Maizena®, soluble starch, amidex, and amylose. The nanoemulsions comprise in a single stable phase varying amounts of water, kerosene, Flotigam EDA® (collector), and n-butyl alcohol, allowing all flotation reagents to be added at the same time, reducing interfacial tension and favoring their application in the process. Microflotation tests were performed in a modified Hallimond Tube and the zeta potential values of the minerals were determined in the presence and absence of reagents. Quartz floatability was not affected by depressants, even when concentrations of 100ppm of depressant were used in the nanoemulsion. The determined isoelectric point of quartz (pH 2). High levels of hematite depression were obtained for all depressants (80%–90% depression). Quartz floatabilities of up to 95% were achieved by using nanoemulsions in the process.

Effects of the calcite on quartz flotation using the reagent scheme of starch/dodecylamine

Quartz and calcite are the representative gangue minerals exited in the hematite ores while the interactions between these gangue minerals are still unknown. The roles of calcite slimes on the quartz flotation using corn starch as the depressant and dodecylamine (DDA) as the collector were studied though micro-flotation tests, zeta potential measurements and DLVO theory calculations. The micro-flotation results showed that calcite significantly affected the quartz flotation. The flotation recovery of quartz largely reduced with the addition of fine calcite particles under the starch/DDA reagent scheme. The zeta potential results illustrated that there is an electro-steric attraction between quartz and calcite slimes, leading to the coating of calcite on quartz surface. The depressant starch could be absorbed onto the surface of coated calcite slimes and prevented the adsorption of DDA collector, thereby decreased the floatability of quartz. DLVO calculation confirmed the hetero-coagulation in the quartz-calcite slimes system.

Analysis of quartz floatability using design of experiments

Abstract Quartz floatability in cationic reverse flotation depends on the suitable choice of surfactant type and the conditions under which they are applied. The design of experiments (DOE) allows the evaluation of process variables, in a structured and independent way, with statistical validation and a limited number of tests. Tests of microflotation of quartz, in the size range -150 +75 µm, using factorial design of experiments, showed that etherdiamine leads to higher level of quartz floatability than ethermonoamine, favored by increase in collector concentration, at the high level of pH tested (11.0). Floatability values above 90% were achieved with the use of 3 mg/L of ether diamine for both pH levels, while with ether monoamine the target was reached only at pH 11.