Mineral Surfaces Research Articles

Comments: Pore Space Leasing: Insights From a Bakken Surface Owner’s Perspective

During a trip to western North Dakota last month to visit my family, I met with a long-time friend, Dick, who holds subsurface mineral rights and surface rights in the Bakken area. Over coffee, German sausage, and kuchen, our conversation naturally turned to the leasing of pore space. Dick has lately been approached by landmen with what they describe as “great deals” for purchasing the underlying pore space associated with his surface rights. They hesitate to provide specific offers. Instead, he described the initial interactions as “like making a deal for a new car or tractor.” The landmen reply, “I’ll need to go back to the client [my boss or manager] with your questions.” Sound familiar? Like most US states, pore space ownership correlates with surface ownership in North Dakota. In August 2022, the North Dakota Supreme Court clarified the rights of surface owners and the need for compensation for pore space use. It also created uncertainty for oil and gas operators who previously had more latitude in using pore space without compensation. Dick knows his way around the dealmaking involved in oil and gas rights leasing, having been involved in many landmen inquiries in the days of the Bakken boom and subsequent wheeling and dealing. However, pore space leasing is relatively nascent and faces similar unknowns like the early days of Bakken pitches. During his research, he came up against the same walls I have over the years while writing about pore space leasing for carbon sequestration. Becoming more apparent as deals gain momentum is the lack of specifics for comparable deals. As when purchasing a home, identifying “comps” for similar properties is a necessary part of the process. But the amounts paid for pore space are closely held, generally not publicly available. It’s impossible to determine if a deal is good or bad. Is the compensation fair? And individual surface owners and landowners rights associations (and/or their attorneys) are aware of the 45Q tax credit of $85/tonne of CO2 captured and stored available to the project developer/operator under the 2022 US Inflation Reduction Act. How should this be factored into the determination of fair compensation? For example, the Ohio River Valley Institute (ORVI), a think tank focused on the Appalachian region, in March described a proposal by Tenaska Inc. to lease underground pore space across seven counties (approximately 80,000 acres) in Ohio, Pennsylvania, and West Virginia for the sequestering of 150 million tons of CO2. In a document proposing terms for the acquisition of nearly 1,400 acres of pore space in county parklands in Washington County, Pennsylvania, Tenaska offered about $4 million for the county’s 2.6-million-metric-ton share of the CO2 between 2027 and 2056, or about $1.50 per metric ton. The ORVI called the deal “ridiculous and borderline insulting.” It supports this declaration by highlighting a comp available from August 2023. Mountaineer GigaSystem LLC offered the state of West Virginia a royalty of $3.35 per metric ton to sequester CO2 on public land in Mason County—more than two times what Tenaska is offering Washington County. It also made the point that the ultimate cost of capturing and sequestering the CO2 will not be borne by Tenaska or its customers. The 45Q tax credit will provide Tenaska $423 million annually for sequestering 5 million tons of CO2 annually. The region’s lease revenue will be $7.5 million. To align with the available comp, ORVI said Tenaska’s offer should at least match Mountaineer’s $3.35 instead of the proposed $1.50 per metric ton. In the western US, ExxonMobil is seeking to pay the US Bureau of Land Management (BLM) to inject 150 million tons of CO2 over the course of 20 years into 100,000 subsurface acres of pore space on federal lands. The proposed Snowy River CO2 project in Carter County, Montana, is still in the environmental assessment and public comment phase, and the BLM’s compensation for the use of the land is not yet publicly disclosed or finalized. Our takeaway after finishing the sausage and kuchen? As pore space leasing evolves, landowners like Dick face a complex landscape of uncertain deals and opaque compensation. With legal clarifications and potential tax credits in play, navigating these new frontiers requires keen insight and vigilance to ensure fair and beneficial agreements for all involved.

Study of Silica Sinter Mineral Content, Surface Temperature, and Fluid Type of Waya Makawa Hot Spring Ploly Village, Makian Island, North Maluku

Study of Silica Sinter Mineral Content, Surface Temperature, and Fluid Type of Waya Makawa Hot Spring Ploly Village, Makian Island, North Maluku

Effects of biodegradable dispersants on the separation flotation of chalcopyrite and serpentine

The presence of serpentine slime coating on the chalcopyrite surfaces severely affects the chalcopyrite floatability. In this study, three biodegradable polymers, namely polyaspartic acid (PASP), polyepoxy succinic acid (PESA), and hydrolyzed polymaleic (HPMA) were used as dispersants to disperse the chalcopyrite and serpentine particles. The micro-flotation experiments demonstrated that the application of dispersants in the flotation effectively reduced the negative impact of serpentine over a wide pH range, restoring the recovery rate of chalcopyrite to about 85%. The XPS analysis revealed that the dispersants could be adsorbed onto the mineral surfaces through the binding of carboxyl groups with the magnesium or copper sites. As a result, the surface potentials of serpentine changed from positive to negative, while that of the chalcopyrite became even more negative, resulting in a strong electrostatic repulsion between them, which effectively eliminated the covering of the serpentine on the chalcopyrite surface. The AFM force measurements indicate a weak interaction of the polycarboxylic acids dispersants with the surface of chalcopyrite. Consequently, the adsorption of dispersants on the chalcopyrite surface has an insignificant impact on the subsequent adsorption of collectors, which is further supported by the adhesion force measurements between the air bubble and mineral surfaces. Therefore, the application of polycarboxylic acid dispersants in the flotation significantly enhanced the floatability of chalcopyrite in the presence of the serpentine fines.

Impact of mineral reactions and surface complexation on the transport of dissolved species in a subterranean estuary: Application of a comprehensive reactive transport modeling approach

Subterranean estuaries (STE) are hotspots of biogeochemical reactions. Here, dissolved constituents in waters of terrestrial and marine origin are transformed before they discharge to the coastal oceans. The involved biogeochemical reactions are complex and non-linear, calling for the application of numerical reactive transport modeling (RTM) to improve the process understanding. The aim of this study was to assess the roles of organic matter degradation and coupled secondary mineral reactions for the fate of dissolved species in STEs of sandy beaches. A comprehensive RTM approach was applied for this purpose, accounting for the effects of ion activities, pH, pe, redox reactions, mineral equilibria (calcite, goethite, siderite, iron sulfide, hydroxyapatite and vivianite) as well as surface complexation. Results show that the STE biogeochemistry and associated species fluxes are very sensitive to the assumed reaction network. For example, inorganic carbon and pH were largely controlled by calcite and siderite dynamics, and dissolved Fe2+ and HS- were precipitated as goethite, siderite and/or iron sulfides. Moreover, PO43- concentrations were affected by both the formation of vivianite or hydroxyapatite as well as surface complexation. This work helped to establish the relative importance of some of the major biogeochemical processes in the STE. However, further field studies are needed to understand which processes play a role in real-world STEs, including an exploration of the deep subsurface of STEs. Such field-based observations will improve our conceptual process understanding, which is key to developing well-constrained RTMs.

Environmental fate of monosodium methanearsonate (MSMA)-Part 1: Conceptual model.

Monosodium methanearsonate (MSMA), the sodium salt of monomethylarsonic acid (MMA), is used as a selective, broad-spectrum contact herbicide to control weeds in cotton and a variety of turf. In water, MSMA dissociates into ions of sodium (Na+) and of MMA-, which is the herbicide's active component. Certain soil microorganisms can methylate MMA to dimethylarsinic acid (DMA) other microorganisms can demethylate MMA to inorganic arsenic (iAs). To predict the groundwater concentration of iAs that may result from MSMA application, the processes affecting the environmental behavior of MSMA must be quantified and modeled. There is an extensive body of literature regarding the environmental behavior of MSMA. There is a consensus among scientists that the fate of MMA in soil is controlled by microbial activity and sorption to solid surfaces and that iAs sorption is even more extensive than that of MMA. The sorption and transformation of MMA and its metabolites are affected by several factors including aeration condition, temperature, pH, and the availability of nutrients. The precise nature and extent of each of these processes vary depending on site-specific conditions; however, such variability is constrained in typical MSMA use areas that are highly managed. Monomethylarsonic acid is strongly sorbed on mineral surfaces and becomes sequestered into the soil matrix. Over time, a greater portion of MMA and iAs becomes immobile and unavailable to soil microorganisms and to leaching. This review synthesizes the results of studies that are relevant for the behavior of MSMA used as a herbicide to reliably predict the fate of MSMA in its use conditions. Integr Environ Assess Manag 2024;20:1859-1875. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

The adsorption mechanism of NH4+ on clay mineral surfaces: Experimental and theoretical studies

In-situ leaching based on NH4+ is commonly employed for the separation and extraction of rare earths. However, the residual ammonium salt is affiliated on clay minerals, and liable to be leached out which poses a serious threat to the aquatic environment. To better develop the leaching agents for rare earth extraction based on ammonium ions, some fundamental data on the interaction between NH4+ and minerals must be investigated. This study explores the adsorption mechanism of the primary constituent minerals of rare-earth ores on ammonium ions. According to the density functional theory (DFT) calculations via first principles, the plane of montmorillonite (001), halloysite (001), kaolinite (001), kaolinite (00−1), illite (001) and illite (010) electron density difference in the adsorption process shows that NH4+ is adsorbed on the surface of clay minerals by electrostatic action and hydrogen bonding, and the average adsorption energy of NH4+ is in the order of montmorillonite > halloysite > illite > kaolinite. Correspond with the theoretical results, the experiments testified the microscopic mechanism of NH4+ adsorption. The residual ammonium salts in weathered crust leaching rare earth ores are adsorbed on montmorillonite, halloysite, illite and kaolinite with a capacity of 0.56, 0.45, 0.38 and 0.34 mg/L, respectively. Most of the absorbed ammonium on clay minerals was found to be with the water-soluble state rather than ion-exchange state. These water-soluble forms can be efficiently eluted by disrupting their interface interactions to leach out.

Investigation of Seasonal Variations in Glencore’s Kidd Creek Cu-Zn ore flotation

Water management in mining and mineral processing operations is becoming increasingly important in the 21st century due to water scarcity concerns and as part of a greater push for sustainability. The aim of this study is to investigate the impacts of seasonal water quality in the Glencore’s Kidd Creek copper-zinc concentrator in Timmins, Ontario, Canada.Mineralogy results indicate that the Kidd ore consists primarily of pyrite (22%) and quartz (22%), followed by pyrrhotite (9%), sphalerite (8%) and chalcopyrite (7%).Investigating the flotation of Kidd Creek ore at bench scale between March 2022 and February 2023 identified seasonal trends in both copper and zinc flotation. However, post hoc analysis could not identify which months were significant. Oxidation of the ore samples or the use of process water could have contributed to an increase in sphalerite floated to the copper concentrate by 20 to 30% in summer months. Sphalerite surfaces in July have higher intensities of copper and collector species resulting in higher zinc recovery in the copper concentrate. Species in the process water and on the mineral surfaces may partially explain the differences in performance between the spring and the summer months.

The selective flotation separation of apatite from dolomite and calcite utilizing a combination of 2-chloro-9-octadecenoic acid collector and sodium pyrophosphate depressant

In apatite flotation, oleic acid is a commonly used fatty acid collector but is limited by its selectivity and solubility. Acknowledging the reactivity of the α-C atom within oleic acid molecular structure, this study introduces a Cl atom at this site, leading to the synthesis of a novel collector, 2-chloro-9-octadecenoic acid (2-Cl-9-ODA). This collector is utilised in the flotation separation of apatite from its associated carbonate gangue minerals, dolomite and calcite. Flotation experiments reveal that the application of 2-Cl-9-ODA collector, in conjunction with sodium pyrophosphate (NaPP) inhibitor, facilitates the effective separation of these three minerals. Analysis on these mineral surface solubilities, augmented by NaPP, illustrates a solubility sequence: calcite surpasses dolomite, which marginally exceeds apatite. Interestingly, this sequence inversely matches the flotation recoveries, suggesting the superior recoveries of apatite over dolomite and significantly over calcite. The inhibition effect of NaPP on dolomite and calcite flotations is inferred to associate closely with the scarcities of the surface Ca2+ ions. Moreover, adsorption quantity and zeta potential experiments indicate that NaPP depressant significantly reduces the adsorption amounts of 2-Cl-9-ODA on dolomite and calcite surfaces, while barely affecting its adsorption on apatite. First-principles calculations show that the Cl atom introduction allows 2-Cl-9-ODA collector to adopt a parallel adsorption configuration on the mineral surfaces, decreasing its collecting abilities. This research offers theoretical underpinnings for the industrial use of 2-Cl-9-ODA collector in apatite flotation and delivers key understandings for the advancement of groundbreaking apatite flotation collectors.

Co-modification of chrysocolla with ammonia and 1,2-diaminopropane and its response to flotation

Chrysocolla is a typical copper oxide with unique structural characteristics and a variable chemical composition, which make its recovery by flotation considerably challenging. A novel ammonia-1,2-diaminopropane-xantahte (NH3·H2O-1,2-DAP-xanthate) flotation method was proposed in this study for its effective recovery. Compared with the 1,2-DAP-xanthate system, the recovery of chrysocolla was substantially increased from 73.43 % to 95.26 % using the NH3·H2O-1,2-DAP-xanthate system. X-ray photoelectron spectroscopy, zeta potential, Fourier transform infrared spectroscopy, xanthate adsorption capacity, and time-of-flight secondary ion mass spectrometry analyses showed that the increase in the chrysocolla flotation recovery was attributed to an increased in the effective xanthate adsorption on the chrysocolla surface. The additional adsorption of xanthate could be attributed to the alteration of the surface properties of the chrysocolla by NH3·H2O, which exposed more copper sites and reduced the hydrophilic component of the surface. This promoted the effective adsorption of more 1,2-DAP on the mineral surface. Thus, more chelated copper formed, which improved the mineral surface activity and increased the number of active sites interacting with the xanthate.

A Third of Organic Carbon Is Mineral Bound in Permafrost Sediments Exposed by the World's Largest Thaw Slump, Batagay, Siberia

ABSTRACTOrganic carbon (OC) in permafrost interacts with the mineral fraction of soil and sediments, representing < 1% to ~80% of the total OC pool. Quantifying the nature and controls of mineral–OC interactions is therefore crucial for realistic assessments of permafrost‐carbon‐climate feedbacks, especially in ice‐rich regions facing rapid thaw and the development of thermo‐erosion landforms. Here, we analyzed sediment samples from the Batagay megaslump in East Siberia, and we present total element concentrations, mineralogy, and mineral–OC interactions in its different stratigraphic units. Our findings indicate that up to 34 ± 8% of the OC pool interacts with mineral surfaces or elements. Interglacial deposits exhibit enhanced OC–mineral interactions, where OC has undergone greater microbial transformation and has likely low degradability. We provide a first‐order estimate of ~12,000 tons of OC mobilized annually downslope of the headwall (i.e., the approximate mass of 30 large aircrafts), with a maximum of 38% interacting with OC via complexation with metals or associations to poorly crystalline iron oxides. These data imply that over one‐third of the OC exposed by the slump is not readily available for mineralization, potentially leading to prolonged OC residence time in soil and sediments under stable physicochemical conditions.

Selective adsorption mechanism of polyoxyethylene alkyl amine in reverse flotation separation of fayalite and magnetite without depressant

Effective flotation separation of magnetite from iron-bearing silicate minerals is difficult with conventional collectors because of their similar surface properties. In this work, polyoxyethylene alkyl amine (PAE), which is easy to prepare and has high surface activity, was used for the reverse flotation separation of fayalite and magnetite for the first time, and its selective adsorption mechanism was revealed. The micro-flotation tests results show that compared with dodecylamine (DDA), the separation effect of PAE on fayalite and magnetite was significantly improved. When pH was 6.5 and PAE dosage was 20 mg/L, the selective separation of fayalite and magnetite can be achieved by reverse flotation without depressant. The results of zeta potential and contact angle measurement shown that PAE was significantly adsorbed on fayalite compared with magnetite, so the hydrophobicity of fayalite treated by PAE was effectively enhanced. In addition, the differential adsorption of PAE on fayalite and magnetite was further verified by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulation, where PAE was adsorbed on the surface of fayalite by electrostatic adsorption and hydrogen bonding, while electrostatic repulsion caused PAE to be removed from the surface of magnetite. The angle between the ethylene oxide chains of PAE at adsorption equilibrium reflects the stress state of NH+ and –OH. Therefore, the selective flotation separation of magnetite and fayalite was realized based on the electrical difference of mineral surface and PAE structural characteristics.

On the Use of Styrene-Based Nanoparticles to Mitigate the Effect of Montmorillonite in Copper Sulfide Recovery by Flotation.

Clay minerals have different negative effects on the froth flotation process such as low adsorption of collectors on valuable minerals, increased pulp viscosity, and the reduction in recovery and grade concentrates of copper sulfides. This study aims to evaluate the use of polystyrene-based nanoparticles (NPs) for the froth flotation of chalcopyrite and their ability to mitigate the negative effect of montmorillonite on the recovery of this sulfide. The experimental stage consisted of preparing a type of polystyrene-based nanoparticle (St-CTAB-VI), which was analyzed by dynamic night scattering (DLS) to establish its hydrodynamic size. Then, the effect of NPs on chalcopyrite's angle's in the presence and absence of montmorillonite (15%) was evaluated and compared with the contact angle achieved using potassium amyl xanthate (PAX) and a mixture of PAX and NPs. In addition, zeta potential measurements were carried out to investigate the interactions between the chalcopyrite and the montmorillonite or the NPs under fixed concentrations and microflotation tests were performed employing different times to evaluate the chalcopyrite recovery in the presence of montmorillonite, using NPs and mixtures with PAX. Finally, turbidity analysis as a function of time was performed to evaluate the occurrence of sedimentation and flocculation phenomena in suspensions of 15% montmorillonite in the presence and absence of chalcopyrite, nanoparticles, and mixtures of NPs and PAX. The results indicated that the mixture of NPs and PAX contributed to increasing the contact angle of chalcopyrite in the presence of montmorillonite. This can be associated with the presence of molecular and nanometric collectors that generated a higher hydrophobicity on the chalcopyrite particles, contributing to reducing the presence of clay minerals on the mineral surface. In addition, the mixture of NPs and PAX promoted the generation of nanoparticles on the sulfide mineral surface, which helps to detach the slime and facilitate the bubble/mineral attachment step during flotation.

Evolution of sulfur species on malachite surfaces in the presence of calcium and magnesium ions and implications for xanthate flotation

The depletion of mining resources has led to a sharp increase in gangue minerals. The use of flotation technology with seawater, which is rich in Ca2+ and Mg2+, has gradually increased. However, these ions may affect the flotation process. Herein, we study the effects of the addition of Ca2+ and Mg2+ on the process and products of malachite sulfidization. Analysis of the S layer on the mineral surface indicates that the quantities of S components generated on the malachite surface decrease in the presence of Ca2+ and Mg2+. Additionally, Ca2+ and Mg2+ induce the excessive generation of oxidized S species (SOn2−) during sulfidization, which inhibits the formation of Cu2S. Furthermore, both the solubility of malachite and the consumption of collector ions in the solution increase in the presence of Ca2+ and Mg2+. Microflotation experiments confirm that Ca2+ and Mg2+ result in insufficient sulfidization properties on the malachite surface and reductions in the activity of the sulfidization products, leading to a decrease in sample floatability.

STPP and EDTMPS synergistically enhance the flotation separation of scheelite from fluorite and calcite

In this paper, the synergistic effects of sodium tripolyphosphate (STPP) and sodium ethylenediamine tetramethylenephosphonate (EDTMPS) for the flotation separation from fluorite and calcite were investigated. Flotation tests conducted at various scales demonstrated that the combined inhibitor of STPP and EDTMPS can significantly enhance the separation efficiency of scheelite from fluorite and calcite. For low-grade scheelite in Luanchuan, the combined inhibitor can improve the WO3 grade of scheelite roughing concentrate without compromising the recovery of scheelite roughing, thereby reducing the burden of the Petrov process. Based on the results from X-ray photoelectron spectroscopy and atomic force microscopy, coupled with other surface analysis, it’s evident that STPP and EDTMPS are more readily adsorbed onto the surfaces of fluorite and calcite due to the unique in electrostatic repulsion and steric resistance.The co-adsorption of STPP and EDTMPS covers a more extensive mineral surface area, enhancing the hydrophilicity of fluorite and calcite surfaces. This, in turn, heightens the resistance of the mineral surfaces to subsequent sodium oleate (NaOL) adsorption. As a result, the floatability difference among the three calcium-bearing minerals is expanded, optimizing the separation efficiency.

Auxiliary collector optimizing foam characteristic and adsorption behavior towards efficient flotation desilication of bauxite

The desiliconization of bauxite through flotation poses challenges due to the limitations of conventional collectors like oleic acid. Hence, there is an urgent need to explore more selective alternatives to enhance efficiency. In this study, sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate (SLS), and benzohydroxamic acid (BHA) are explored as auxiliary collectors with sodium oleate (NaOL) to enhance its efficiency and selectivity. Bench-scale tests reveal that combined collectors exhibit superior flotation efficiency and concentrate quality compared to NaOL alone, both in laboratory settings and actual bauxite ores. Detailed mechanistic insights are provided from both macroscopic and microscopic perspectives. Macroscopic analyses uncover differences in foam and pulp properties among the combined collectors, indicating that the NaOL + BHA system offers moderate foaming performance, stability, and homogeneity, enhancing collection efficacy and selectivity. Microscopic investigations elucidate the adsorption mechanism between combined anionic collectors and mineral surfaces using the quartz crystal microbalance with dissipation (QCM-D) and Fourier transform infrared spectroscopy (FTIR). QCM-D analysis shows that SDS, SLS, and BHA weaken NaOL adsorption on kaolinite surfaces and accelerate reagent desorption, with BHA having the most significant effect. These findings provide valuable insights for optimizing bauxite flotation processes with improved efficiency and selectivity.

An ab-initio deep neural network potential for accurate large-scale simulations of the muscovite mica-water interface

Mineral-water interfaces play a critical role in several geochemical processes relevant to the habitability of our planet. These processes are often underpinned by the hydration of the ions covering the mineral surface and the resultant ion exchange with the aqueous environment. Muscovite mica, whose surface is nominally covered by K + ions, has long been considered an ideal system for probing some of these processes. However, despite several decades of both experimental and computational work, there still remains a lack of consensus on ion hydration and exchange at the mica-water interface. To obtain a detailed microscopic picture of these processes, we have developed an ab-initio based deep neural network potential (DP) describing the potential energy surface (PES) of the mica(001)-water interface. Our training dataset consisted of bulk mica, bulk liquid water, the mica(001) surface in vacuum and the explicit mica(001)-water interface, both with different surface K + arrangements. The trained model is able to reproduce the energies and forces derived from Density functional theory (DFT) based on the SCAN exchange correlation functional with good accuracy. For the surface in vacuum, K + ions located in the ditrigonal cavities composed of 2 Al atoms are predicted to be energetically more favourable, while the specific surface arrangement of K + ions does not affect the water density profile at the mica-water interface. The developed model sets the stage for estimating the energetics of the ion-exchange process at affordable computational cost without compromising the accuracy of first-principles methods.

The depression mechanism of magnesium on the flotation of sphalerite with different iron contents: DFT and experimental studies

Previous studies have not examined the effect of iron content in sphalerite on magnesium depressing sphalerite. Herein, the impact of magnesium on the sphalerite flotation with different iron contents was investigated through experiments and various analytical techniques in this work. Flotation trials showed that the depression of magnesium on the flotation of sphalerite could be significantly improved with the increasing iron contents. Solution chemical calculations indicated that MgOH+ was the dominant group in solution under high-alkalinity environment. Zeta potential measurements demonstated that substitution of iron in sphalerite promoted adsorption of MgOH+ on the mineral surface. FTIR analysis indicated that Mg(OH)2 was more likely to adsorb on the surface of high iron marmatite. Surface properties investigations corroborated that Mg could produce Mg(OH)2 on the high-iron marmatite surface, improving the hydrophilicity of the surface. DFT calculations confirmed that the surface of iron-substituted sphalerite was more likely to interact with Mg(OH)2 than MgOH+. The present work provides new mechanistic sight for the depression of magnesium on the flotation of sphalerite with different iron contents.

Preparation of superior magnetite concentrate from waste tailings with clean energy: Semi-industrial utilization, economic profits, and environmental benefits

The effective utilization and clean recycling of tailings are important to solve land occupation and waste mine pollution problems. A semi-industry experiment of hydrogen-based mineral phase transformation for tailings is conducted with a roasting temperature of 500 °C, a reducing gas concentration of 20 %, a total gas volume of 12 m3/h, and a handing capacity of 100 kg/h. A concentrate product with an iron grade of 66.75 % and a recovery of 82.79 % was obtained. The detail roasted iron phases of 23.96 % Fe3O4 (A) and 47.93 % Fe3O4 (B) were obtained. The maximum saturation magnetization increased from 6.69 to 18.96 A·m2·kg−1 after roasting. The surface of Fe3O4 occurred on the iron mineral surface. The SEM-EDS results showed the order of reduce behavior. In addition, the pollutions of the roasting process were controlled strictly, and the final benefit was calculated to be $33.86 million.

Organoclays Based on Bentonite and Various Types of Surfactants as Heavy Metal Remediants

The rapid industrial development of civilization has led to the need for the development of new materials to clean up chemically contaminated wastewater and soils. Organoclays, based on smectite minerals and various types of surfactants, are one of the most effective sorbents for adsorbing organic and inorganic pollutants. Organoclays are clay minerals that have been modified by the intercalation or grafting of organic molecules. The main mechanism of interaction between organic substances and organoclays involves the adsorption of the substances onto the surface of the clay mineral, which has an expanded structural cell. Various types of surfactants can be used to synthesize organoclays, including cationic, anionic, and amphoteric surfactants. Each type of surfactant has different properties that affect the clay’s ability to sorb. Cationic forms of trace elements, such as heavy metals, can also be adsorbed by organoclays. Data on the adsorption of these substances by organoclays are provided, along with information on how to synthesize them using various surfactants. This review also discusses the main mechanisms of interaction between these substances and clays and the various methods used to create organoclays. It is clear that the adsorption of heavy metals by organoclays is not influenced by their structure or properties, as they belong to the category of surfactant, but rather by their overall chemical structure and characteristics. The wide variety of surfactant types leads to different effects on the adsorption properties of trace elements.

Process and mechanism of recovery of lepidolite and spodumene by flotation with synergistic action of alkali corrosion and Mg(II)

How to efficiently extract lithium resources from raw ore plays an important role in promoting the development of new energy fields dominated by lithium. Therefore, this paper proposes a co-flotation process for lepidolite and spodumene. The process involves synergistic alkaline corrosion treatment synergistic with magnesium (Mg2+) ion activation. Micro-flotation experiments had proven the high efficiency of the process for recovering the two main lithium-containing minerals in this paper. Alkaline corrosion and Mg2+ synergistic action could effectively promote the adsorption of the collectors on the mineral surface using adsorption capacity detection, X-ray photoelectron spectroscopy detections, and zeta potential measurement. At the same time, there were adsorption differences between the two minerals under different treatment conditions. Additionally, the influence of alkali corrosion conditions on the morphology of the two minerals, the flocculation state after synergistic activation, and the mechanism and difference of adsorption morphology were explored through particle size analysis, scanning electron microscope measurements, energy dispersive spectrometer detection, and atomic force microscope detection.