Abstract
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 SiO
2
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.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Dodecylamine is one of the most commonly used amine collectors for the reverse flotation of magnesite ore. Through a combination of experimental research and computational simulation, the effect of ...n-octanol on the removal of impurities by the reverse flotation of magnesite ore was studied. The test results show that when the dosage of dodecylamine was 60 mg/L, the flotation rates of magnesite and dolomite were 59.53% and 58.02%, respectively, and the flotation rate of quartz was 97.60%. In the presence of n-octanol, the flotation rate of magnesite decreased to 56.41%, and the flotation rates of dolomite and quartz increased to 61.30% and 99.59%, respectively. The test results show that the addition of n-octanol can improve the selectivity of minerals under the same amount of collector. The adsorption of dodecylamine (dodecylamine and n-octanol) on the surface of magnesite, dolomite and quartz was simulated using quantum chemical calculations based on density functional theory (DFT) and implemented in the CASTEP module of Materials Studio. The results show that dodecylamine can adsorb to magnesite, dolomite and quartz, and the adsorption effect was strongest on quartz. After adding n-octanol, the population value of the bond between the agent and magnesite decreased from 0.19 to 0.17, indicating that the adsorption effect of the agent on magnesite was weakened. The population value of the bond between the drug and dolomite increased from 0.19 to 0.23, indicating that the adsorption effect of the drug on dolomite was enhanced. H28, H29, and H2 in the drug form bonds with O12, O20, and O20 on the surface of quartz (101), respectively, and the population values were 0.43, 0.25, and 0.09, respectively. The adsorption sites of the drug and the quartz were increased, and the adsorption effect of the quartz was markedly improved. The test and simulation results show that the dosage of the agent can be reduced in the presence of n-octanol. N-octanol is not only beneficial to the removal of silicon by amine reverse flotation but also has a certain beneficial effect on the removal of calcium by reverse flotation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To enhance the performance of traditional cationic collector, a novel polyhydroxy amine collector N-(2,3-Propanediol)-N-dodecylamine (PDDA) was designed by introducing one propylene glycol group into ...dodecylamine (DDA). It was prepared by a nucleophilic substitution reaction, which showed better solubility and hydrophobicity than DDA and was firstly employed as the collector for the separation of hematite and quartz. Flotation tests showed that PDDA had an excellent flotation performance and significantly better selectivity than DDA. In addition, the flotation performance and adsorption mechanism of PDDA on hematite and quartz surfaces were studied using Fourier transform infrared spectroscopy (FT-IR), zeta potential and X-ray photoelectron spectroscopy (XPS) tests. These results demonstrated that the interaction between PDDA and the minerals’ surfaces was mainly electrostatic adsorption and hydrogen bond, while PDDA tended to adsorb on the surfaces of quartz more than that of hematite. Performance optimization of amine collectors by introducing hydroxyl was also verified, which was of great meaning to the design, development, and application of the polyhydroxy cationic collector. In conclusion, PDDA could be used as a potential collector in the flotation separation of quartz and hematite.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Interpersonal touch is intimately related to the emotional bond between the touch giver and the touch receiver. Which bodily regions we touch in those individuals in our social network is ...relationship specific. Perception of interpersonal touch is altered in psychiatric disorders characterised by body image disturbances (BIDs). Here, we examined whether the 'imagined' experience of social touch in individuals with BIDs is body topography- and relationship-specific. By using an interactive media mobile App, the Virtual Touch Toolkit, high versus low levels of BIDs participants completed heatmaps of full-body virtual avatars, to indicate the body regions they find soothing/unpleasant to be touched by a loved one versus an acquaintance. Self-reports of interoceptive awareness and dysmorphic concerns were also measured. Overall, imagined touch was rated as the most soothing when received from a loved one, and also when this was delivered to 'social' body regions. The importance of the social relationship for the imagined tactile interactions was particularly evident for the high levels of BIDs group, with greater problems with interoceptive awareness predicting higher soothing touch ratings when this was received by a loved one. Despite the evidence that imagined bodily contacts between meaningful people is the most pleasant for socially acceptable bodily regions, our findings may suggest a greater sensitivity to relation-specific bodily patterns of social touch particularly in the high level of BIDs group. Heightened interoceptive awareness may also play a key role in this experience of bodily affective contacts. Future research for body-oriented therapy for BIDs is encouraged to systematically probe the efficacy of imagined social touch interaction protocols which use more plausible, ecological, scenarios where touch is delivered by loved ones and to socially acceptable bodily regions.
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Semi-autogenous (SAG) mills are widely used grinding equipment, but some ore with critical particle sizes cannot be effectively processed by SAG mills and turned into pebbles. This research aims to ...analyze and compare the properties of raw ore and pebbles from a zinc- and tin-bearing ore. The results show that the contents of sphalerite, cassiterite, biotite, antigorite, pyroxferroite, ferroactinolite, and ilvaite in the raw ore are higher than those in the pebbles, and that the pebbles have higher contents of hedenbergite, chlorite, epidote, actinolite, etc. Meanwhile, the abrasion and impact resistance of pebbles is greater than that of the raw ore. In addition, the sphalerite is evenly embedded, and the grinding process is regular. Fine cassiterite associated with harder minerals is difficult to dissociate; it is often found in softer or brittle minerals which may be easily ground into ore mud. The cassiterite in the pebbles is associated with hard and brittle hedenbergite and soft chlorite, making it difficult to recover. This research provides a good foundation for evaluating the recovery value of pebbles and improving the productivity of the SAG process.
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CEKLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
The adoption of machine learning (ML) models has ignited a paradigm shift in seismic analysis, fostering enhanced efficiency in capturing patterns of seismic activity with reduced need for ...time-consuming user interaction. Here, we investigate automated event detection and extraction of seismic phases using two widely used ML models: EQTransformer and PhaseNet. We applied both the models to four weeks of continuous recordings of aftershocks using a temporary array following the 30 November 2022, ML 5.6 earthquake near Peace River, Alberta, Canada. Both the tools identified >1000 events over the recording period. The aftershocks are located in close proximity to the ML 5.6 mainshock as well as to wastewater disposal operations that were ongoing at the time. Both the methods reveal an aftershock distribution that was not identified by the regional network; however, we find that events detected by PhaseNet have smaller event location errors and better depict subtle fault structures at depth, despite identifying ∼200 events less than EQTransformer. Our results highlight the advantages of using ML models for rapid detection and assessment of seismicity following felt events, which is important for rapidly assessing seismic hazard potential and risk.
Because of the viscoelasticity of the subsurface medium, seismic waves will inherently attenuate during propagation, which lowers the resolution of the acquired seismic records. Inverse-Q filtering, ...as a typical approach to compensating for seismic attenuation, can efficiently recover high-resolution seismic data from attenuation. Whereas most efforts are focused on compensating for high- frequency energy and improving the stability of amplitude compensation by inverse-Q filtering, low-frequency leakage may occur as the high-frequency component is boosted. In this article, we propose a compensation scheme that promotes the preservation of low- frequency energy in the seismic data. We constructed an adaptive shaping operator based on spectral-shaping regularization by tailoring the frequency spectra of the seismic data. We then performed inverse-Q filtering in an inversion scheme. This data-driven shaping operator can regularize and balance the spectral-energy distribution for the compensated records and can maintain the low-frequency ratio by constraining the overcompensation for high-frequency energy. Synthetic tests and applications on prestack common-reflection-point gathers indicated that the proposed method can preserve the relative energy of low-frequency components while fulfilling stable high-frequency compensation.
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•EO groups improves dispersibility and ion tolerance of AECNa.•Optimal performance is obtained when 3 EO groups inserted.•Ca ions cannot activate quartz with AECNa.•Electrostatic ...interaction between EO groups and ions improves ion tolerance.
Flotation using a fatty acid collector is always restricted by ions, temperature, and other factors in production. In this study, sodiumfatty alcohol polyoxyethyleneether carboxylate with 3, 5, and 7 EO repeating units (AEC3Na, AEC5Na, and AEC7Na, respectively) were synthesized to improve the performance of fatty acids. The flotation performance and adsorption mechanism for calcium species (including calcite, dolomite, and quartz activated by calcium ions) were investigated, and the methods used include flotation tests, surface tension tests, contact angle measurements, X-ray photoelectron spectroscopy (XPS) measurements, and density functional theory (DFT) calculations. The flotation results show that the optimum amount of the AECNa series was lower than that of sodium oleate (NaOL), and the collecting ability decreased gradually with the increase in the number of EO repeating units. Additionally, the EO group has an anti-activation effect on the fatty acid collector, and AECNa will not collect quartz activated by Ca2+ ions. AEC3Na with 3 EO repeating groups has advantages such as better capture ability and dispersibility, and is apromisingcollector in the replacement of fatty acids. The mechanism analysis shows that AECNa collectors still adsorb by forming chemical bond between carboxyl groups and calcium sites on calcite and dolomite surfaces. The EO groups significantly improved the surface activity and dispersibility of fatty acids. Meanwhile, multiple ether bonds in the EO groups can attract ions electrostatically, weakening the effect of ions on the polar group of collectors and thereby leading to the anti-activation effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Novel collector (OBHA) was synthesized and firstly used in bastnaesite flotation.•OBHA exhibited strong collecting ability and good selectivity.•OBHA can achieve the flotation ...separation of bastnaesite from calcite and barite.•Lattice matching plays an important role in selective adsorption process.
In order to improve the flotation separation efficiency of bastnaesite from barite and calcite, a novel collector, octylamino-bis-(butanohydroxamic acid) (OBHA), with large molecular structure and two functional groups was synthesized based on the molecular design of flotation reagents theory. OBHA was adopted as collector in both single, mixed binary and mixed ternary mineral flotation, the results indicated that bastnaesite could be selectively enriched from mixed mineral. Zeta potential measurements, Fourier transform infrared analysis, X-ray photoelectron spectroscopy analysis and DFT calculation were performed to study the selective adsorption mechanism of OBHA. Zeta potential measurements, FTIR spectra analysis and XPS detection demonstrated that OBHA was chemically adsorbed on bastnaesite surface, whereas the interaction between OBHA with calcite and barite was weak. DFT calculation results indicated OBHA matched well with bastnaesite surface thereby improved the selectivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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