Talc Research Articles

Spatially Resolved Elastic Modulus of Magnesium Silicate Hydrate: A Cementitious Material

Spatially Resolved Elastic Modulus of Magnesium Silicate Hydrate: A Cementitious Material

Insights on the effects of carbonates and phosphates on the hydration of magnesia (alumino-)silicate cements

Cements based on magnesium oxide (MgO) and reactive (alumino-)silicates (xSiO2-yAl2O3) have drawn increasing attention owing to their potential to be produced using raw materials with low CO2 emissions. This study examines how the phase assemblages and compressive strengths of magnesia (alumino-)silicate cements are influenced by the addition of sodium hexametaphosphate (NaHMP) and sodium carbonate (Na2CO3). Cement paste samples with a Mg/Si molar ratio of 1.5 and Al/Si molar ratios of 0 and 1.0 were prepared using microsilica (SF) and metakaolin (MK), respectively, and investigated using SEM, TGA, XRD, and 29Si, 27Al, 31P, and 13C MAS NMR. The results showed that the addition of NaHMP and sodium carbonate enhanced the reactivity of the raw materials in the Al-free MgO-SF systems, with magnesium silicate hydrate (M-S-H) being the primary hydrated phase. After 91 days, the degrees of reaction of microsilica were ∼86% and 96% for systems containing 0 and 2.5 wt % Na2CO3, respectively. In contrast, the reactivity of metakaolin in the Al-containing MgO-MK systems was limited to ∼53%, irrespective of Na2CO3 addition, likely due to the excess sodium hexametaphosphate covering the surface of MK. Here, the main reaction products were magnesium aluminosilicate hydrate (M-A-S-H) and hydrotalcite (Mg6Al2CO3(OH)16·4(H2O))-like phases. Despite the MgO-SF systems displaying higher degree of reaction than the MgO-MK systems, the latter exhibited higher compressive strength. Sodium carbonate increased the compressive strength of the MgO-SF systems but decreased that of the MgO-MK systems. Thermodynamic modelling was also carried out and the results generally agreed with the phase formation observed with XRD and solid-state NMR.

Influence of Solid Waste Material Content on the Properties of Steel Slag-Waste Clay Brick Ceramic Bricks

Steel slag and waste clay brick are two common solid wastes in industrial production, and their complex chemical compositions pose challenges to the production of traditional alumina silicate ceramics. To investigate the influence of steel slag and waste clay brick on the performance of CaO–SiO2–MgO ceramic materials, this study examined their effects on the mechanical properties, crystal composition, and microstructure of the ceramics through single-factor experiments. The results demonstrate that when keeping the dosage of waste clay brick and talcum powder constant, a 43% dosage of steel slag yields optimal performance for the ceramic materials with a modulus of rupture of 73.01 MPa and a water absorption rate as low as 0.037%. Similarly, when maintaining a constant dosage of steel slag and talcum powder, a 41% dosage of waste clay brick leads to superior performance of the ceramic materials, with a modulus of rupture reaching 82.17 MPa and a water absorption rate only at 0.071%. Furthermore, when keeping the dosage of steel slag and waste clay brick constant, employing a talcum powder dosage of 24% results in excellent performance for the ceramic materials with a modulus of rupture measuring 73.01 MPa while maintaining an extremely low water absorption rate at only 0.037%. It is noteworthy that steel slag contributes to akermanite phase formation while talcum powder and waste clay brick contribute to diopside phase formation.

The Effects of Organically Modified Lithium Magnesium Silicate on the Rheological Properties of Water-Based Drilling Fluids.

To address the problem of insufficient temperature and salt resistance of existing polymer viscosity enhancers, we designed an organic-inorganic hybrid composite as a viscosity enhancer for water-based drilling fluids, named LAZ, and it was prepared by combining a water-soluble monomer and lithium magnesium silicate (LMS) using an intercalation polymerization method. The composite LAZ was characterized using Fourier transform infrared spectroscopy, transformed target X-ray diffractometry, scanning electron microscopy, and thermogravimetric analysis. The rheological properties of the composite LAZ were evaluated. The composite LAZ was used as a water-based drilling fluid viscosity enhancer, and the temperature and salt resistance of the drilling fluid were evaluated. The results showed that the composite LAZ presented a complex reticulation structure in an aqueous solution. This reticulation structure intertwined with each other exhibited viscosity-enhancing properties, which can enhance the suspension properties of water-based drilling fluids. The aqueous solution of the composite LAZ has shear dilution properties. As shear rate increases, shear stress becomes larger. The yield stress value of the aqueous solution increases as the composite LAZ's concentration increases. The aqueous solution of the composite LAZ exhibits strong elastic characteristics with weak gel properties. The addition of the composite LAZ to 4% sodium bentonite-based slurry significantly increased the apparent viscosity and dynamic shear of the drilling fluid. The drilling fluids containing the composite LAZ had good temperature resistance at 150 °C and below. The rheological properties of brine drilling fluids containing the composite LAZ changed slightly before and after high-temperature aging at 150 °C.

3D-printed calcium magnesium silicates: A mini-review

Calcium magnesium silicates (CMS) represent a class of minerals with diverse applications in fields ranging from geology to materials science. With the advent of additive manufacturing technologies, particularly 3D printing, novel opportunities have emerged for the synthesis and utilization of CMS-based materials. In this mini-review, we provide a thorough overview of recent advancements in the 3D printing of CMS compounds, including diopside (DPS), bredigite (BR), and akermanite (AKT). We discuss the synthesis methods, properties, and potential applications of 3D-printed CMS materials, with a focus on their role in biomedical applications. Furthermore, we highlight challenges and prospects in the field, emphasizing the importance of continued research and innovation in harnessing the full potential of 3D-printed CMS materials.

The impact of environmental humidity on the mechanical property and microstructure of magnesium silicate hydrate cement

Environmental factors have a significant impact on the performance of cement-based materials. As a new type of low-carbon cementitious material, the performance of magnesium silicate hydrate cement (MSHC) under different environmental humidity conditions is crucial for its application. This study aimed to investigate the effects of environmental humidity on the hardening properties of MSHC. Compressive strength tests of MSHC were conducted under four different relative humidity (RH) conditions (RH of 33%, 58%, 75%, and 97%) and water curing (RH-w) condition. Microanalysis techniques were employed to reveal the strength mechanisms of MSHC under different environmental humidity conditions. The results showed that MSHC exhibited the optimal mechanical performance when RH was 75%, reaching 42.29 MPa. When RH was 58%, the compressive strength of MSHC was close to the optimal level, which was 41.02 MPa. However, under other humidity conditions (RH33, RH97, and RH-w), the compressive strength of MSHC was much lower than the optimal level, decreasing by 30.93%, 41.90%, and 63.66%, respectively. Pore structure analysis showed that the volume of detrimental pores (>100 nm) in the sample was the lowest when RH was 75%. Compared with RH75, the volume of detrimental pores in RH33, RH58, RH97, and RH-w increased by 20.47%, 9.83%, 36.77%, and 156.92%, respectively. In addition, the variation of environmental humidity resulted in different polymerization levels in the M-S-H gel, and higher degrees of polymerization were observed when RH was 58% and 75%.

Potentials of spaceborne imaging spectrometer PRISMA, ASTER, and ALOS-1 PALSAR datasets for mineral mapping and geological controls of mineral deposit in Jahazpur, Rajasthan, India

Palaeoproterozoic rocks of the Jahazpur region are well known for talc mineralization and its mining. The present study attempts to identify and map the talc and associated minerals and their structural control using multi-source remote sensing datasets. Remote Sensing studies were carried out using the relative band depth methods for the ASTER dataset for mapping talc and other associated minerals of the region. Principal Component Analysis (PCA), Independent Component Analysis (ICA), and Minimum Noise Fraction (MNF) were applied to the PRISMA dataset to map the lithology of the region. Along with that, the Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) algorithms map the talc and clay minerals using the PRISMA dataset. ALOS – 1 PALSAR dataset had been utilized to delineate the various lineaments present in the region at different angles. The obtained mineral maps form the ASTER had been validated with results of the PRISMA classified map and showed a good number of similarities. The obtained results from remote sensing have been further validated with the help of field survey and XRD analysis which confirms the presence of talc and clay minerals in the region. The structural pattern of the lineament shows the similarity in the direction orientation with the Jahazpur Thrust. Dolomites and clay minerals were mapped around the talc mining region which suggests that the alteration of these minerals played an important role in the formation of talc. Clay minerals were also mapped there and formed due to the weathering of the granites of Berach and Jahazpur present in the region. Both talc and clay deposits are present at the higher lineament density zones which represents the structural control over the mineralization. Therefore, the mineral deposits of the Jahazpur region are mineralogical and structurally controlled.

Development of compound feed recipes for broiler chickens (13-28 days) using vermiculite

Recently, in the CIS countries and abroad, to compensate for the mineral deficiency of feed rations and reduce their cost, substances of natural origin have increasingly begun to be used: zeolites, travertines, sapropels, bentonites, etc. The prlackblem of the widespread use of natural minerals in the diet of farm animals and poultry represents a pressing issue, given their distinctive properties, waste-free technology, environmental friendliness, and relatively low cost. One of these minerals suitable for use in poultry nutrition is vermiculite (hydromica, hydrous silicate of magnesium and iron of variable composition). The purpose of the study is to determine the physicochemical composition of vermiculite from the Kulantau deposit, and its use as a mineral in the production of animal feed and development of compound feed recipes for broiler chickens Cobb500. The physicochemical parameters of vermiculite, a natural mineral, have been determined. The research analyses were carried out in the research laboratory for assessing the quality and safety of food products of the Almaty Technological University. Feed recipes were developed at LLP “AGRO FIT KAPSHAGAY”. The compound feed recipes for Cobb 500 broiler chickens of 13-28 days were tested at JSC “Alel agro”, in poultry house No. 3.

Novel Anti-Wear Performance of Nano Magnesium Silicate Hydroxide in Boundary Lubrication Under High Temperature

Abstract In the operation of the machine, the tribological properties of the lubricant are apt to deteriorate with temperature elevation. Therefore, it is of great significance to seek a lubricant additive with good high-temperature tribological properties. In this study, the tribological performance of nano magnesium silicate hydroxide (MSH) as a lubricant additive were investigated at 40–200 ℃ and the results show that the wear of the sliding surface lubricated by PAO10 with MSH as the additive is very slight. The worn surface was characterized by the scanning electron microscope (SEM), Raman spectrometer, and X-ray photoelectron spectrometer (XPS). The experimental results display that the electrostatic adsorption between [Si4O10]4− released from MSH and steel surface contributes to the formation of SiO2 film; whereas ion exchange reaction between the phase transformation product of MSH in the contact zone and steel surface results in the chemical bonding Si–O–Fe, and the existence of the bonding facilitate the formation of the protective tribofilm with strong adhesion at high temperature.

Antithrombotic pharmacodynamics and metabolomics study in raw and processed products of Whitmania pigra Whitman

ObjectiveAs a traditional Chinese medicine, leech has obvious pharmacological activities in anticoagulantion and antithrombosis. Whitmania pigra Whitman (WP) is the most commonly used leech in the Chinese market. It is often used in clinical applications after high-temperature processing by talcum powder to remove the fishy taste and facilitate crushing. The anticoagulant and thrombolytic active ingredients are protein and polypeptide, which may denaturate and lose activity after high-temperature processing. The rationality of its processing has been questioned in recent years. This study aims to investigate the effect of talcum powder scalding on the antithrombotic activity of WP in vivo and to discuss its pharmacodynamic mechanism in vivo. MethodsRaw and talcum-powdered processed WP were administered intragastrically for 14 days, and carrageenan was injected intraperitoneally to prepare a mouse model of tail vein thrombosis. The incidence rate of tail vein thrombosis and the thrombus area under pathological tissue sections were calculated to evaluate the antithrombotic effect between raw and processed WP. Non-targeted metabolomics was conducted using UPLC-Q-TOF/MS technology to analyze the changes of small molecule metabolites in the body after administration of WP. ResultsAfter intragastric administration, both the raw product and the processed product of WP could inhibit the thrombosis induced by carrageenan, and the processed product had a more apparent antithrombotic effect than the raw product. The administration of WP could regulate the changes of some small molecular metabolites, such as amino acids, lipids, and steroids, in Sphingolipid metabolism and Glycerophospholipid metabolism. ConclusionsBased on the results of pharmacodynamics and metabolomics, processed WP will not reduce the antithrombotic activity of WP. This study provided a scientific basis for the rational use of leeches.

A preliminary study on preparation and properties of magnesia based clinker with zeolite and magnesite

Dead burnt magnesia is the main raw material of magnesium phosphate cement, which is widely used in road repair works. However, due to the high energy consumption and high cost in the production and preparation process of dead burnt magnesia, its application is limited to a certain extent. In this work, a magnesia based clinker containing a considerable number of magnesium oxide and magnesium silicates phase was prepared by co-firing of zeolite powder and magnesite at low temperature (1200–1300 ℃). The results show that high temperature than 1200℃ results in less free MgO. Intermediate phases 2CaO·MgO·2SiO2 formed in clinker at 1250℃ and 1300℃. The workability of the pastes made from calcined cement clinker was proved to be better than that of traditional magnesium potassium phosphate cement (MKPC). The compressive strength can reach 30 MPa after curing for 7 days. Compared with the traditional MKPC, the hydration heat of the new magnesia based cement is greatly reduced. Lower calcination temperature on the cement clinker resulted in fewer cracks and pores on the surface of magnesia based cement and denser structure of the hydration products.

A facile electrochemical immunosensor based on EDTA-Pb2+ complexation reaction

The sensitivity of electrochemical (EC) sensors has been improved through the development of multiple approaches. However, the majority of EC sensors were limited in their practical application by high costs or tedious procedures. Herein, based on ethylenediaminetetraacetic acid (EDTA)-Pb2+ complexation reaction, a facile and affordable immunosensor was designed. Pb2+-magnesium silicate hydrate was served as the sensing substrate. The immunorecognition process was carried out in the Eppendorf tube, and antibody-functionalized Pb2+-polydopamine was utilized as immunoprobe. In the tube, the quantitative and appropriate excess of EDTA was introduced to complex with Pb2+ on the immunoprobes. The remaining EDTA was added to the sensing substrate surface to coordinate with some Pb2+ in it. This leaded to the reduction of the EC signal of Pb2+, which was related to the antigen concentration. Using prostate-specific antigen as the model analyte, the sensitive detection was realized with a low limit of detection (30.49 fg mL−1). Remarkably, the assay results were available within 24 min, sensibly faster than the most existing EC sensors.

Magnesium recovery from ferronickel slag by reaction with sodium hydroxide

Ferronickel (FeNi) slag, as the main solid byproduct of the FeNi industry, has the potential to be utilized other than as roadbed material. To broaden the applications of FeNi slag (such as CO2-capturing materials), there is a need for a treatment that breaks the magnesium silicate bonds and transforms the magnesium into MgO. As an initial study, this research treated FeNi slag by using sodium hydroxide followed by water-washing. The present authors evaluated several alkali treatment variables; such as temperature (523 K and 773 K), time (1–8 h), and mass ratio between FeNi slag and NaOH (1:0.75–1:4). The magnesium in FeNi slag was recovered as MgO. By using a FeNi slag:NaOH mass ratio of 1:2, a temperature of 773 K, and a time of 4 h, 97.34% of the magnesium was recovered, and 83.35% of the silicon was removed. During alkali treatment, the Mg-based compound in FeNi slag undergoes a transformation from MgSiO3 to Mg2SiO4 to MgNa2SiO4 and, finally, to MgO. On the other hand, the Fe-based compound transforms olivine to Fe2O3 to spinel (Fe2MgO4 and Fe3O4) and, finally, to FeNaO2. The alkali treatment process of FeNi slag using NaOH followed by water washing is also known to make the product morphology porous and has a large surface area (11.62 m2/g). In terms of economics, this process will be economical when considering the by-product (Na4SiO4) generated.

Elongated particulate burden in an individual who died of mesothelioma and had an occupational history as a talc “mucker”

Introduction Tissue from a 77-year-old man diagnosed with mesothelioma was referred with a request for identification of the presence of fibrous structures in tissue samples. The individual’s work history including working as a “mucker” at a specific “industrial” talc mine. Methods Ferruginous bodies in the tissue digests as well as asbestos fibers were found. A bulk sample of a talc containing product from that mine was also analyzed. Discussions/Conclusions The correlation between the unique asbestos mineral/fibrous content of the talc to which he was exposed and findings of the same type of asbestos found in his lung is discussed. The type of asbestos found (tremolite) is a “non-commercial” type of asbestos that has been identified in some talc deposits. Tremolite, like all forms of asbestos is a causative agent for mesothelioma-the disease from which this individual suffered.

Evaluation of ED-XRF for the detection of inorganic adulterants in turmeric, paprika and oregano

Herbs and spices are known to be prone to food fraud and accurate analytical tools are needed to detect adulterants. Amongst the potential adulteration, dilution with bulking agents has regularly been reported, especially with inorganic materials such as talc or brick powder. Energy Dispersive X-Ray Fluorescence (ED-XRF) spectrometry is a well-established non-destructive analytical technique for qualitative and quantitative elemental analysis of a wide variety of samples. ED-XRF was here evaluated for the detection of inorganic adulterants in turmeric, paprika and oregano, which were selected as representative for the herbs & spices food category. Magnesium, silicon, and calcium were identified as elements to detect talc, soapstone, brick/clay powder, and chalk inorganic adulterants. ED-XRF successfully detected adulterated samples when spiked down to 5% (w/w) in the selected herbs and spices. With its ease-of-use and speed, ED-XRF is well adapted for the monitoring of inorganic adulteration of herbs and spices along the supply chain.

Nanoclay Hydrogel Microspheres with a Sandwich-Like Structure for Complex Tissue Infection Treatment.

Addressing complex tissue infections remains a challenging task because of the lack of effective means, and the limitations of traditional bioantimicrobial materials in single-application scenarios hinder their utility for complex infection sites. Hence, the development of a bioantimicrobial material with broad applicability and potent bactericidal activity is necessary to treat such infections. In this study, a layered lithium magnesium silicate nanoclay (LMS) is used to construct a nanobactericidal platform. This platform exhibits a sandwich-like structure, which is achieved through copper ion modification using a dopamine-mediated metallophenolic network. Moreover, the nanoclay is encapsulated within gelatin methacryloyl (GelMA) hydrogel microspheres for the treatment of complex tissue infections. The results demonstrate that the sandwich-like micro- and nanobactericidal hydrogel microspheres effectively eradicated Staphylococcus aureus (S. aureus) while exhibiting excellent biocompatibility with bone marrow-derived mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs). Furthermore, the hydrogel microspheres upregulated the expression levels of osteogenic differentiation and angiogenesis-related genes in these cells. In vivo experiments validated the efficacy of sandwich-like micro- and nanobactericidal hydrogel microspheres when injected into deep infected tissues, effectively eliminating bacteria and promoting robust vascular regeneration and tissue repair. Therefore, these innovative sandwich-like micro- and nanobacteriostatic hydrogel microspheres show great potential for treating complex tissue infections.

Dual-functional superhydrophobic coatings on biodegradable Mg alloys via nano-SiO2 particles assisted surface modification

In the exploration of next-generation biocompatible implant materials, magnesium (Mg) alloys have great potential due to their inherent biodegradability. The current study delineates the development of dual-functional coatings for Mg alloys, incorporating zinc (Zn) and calcium (Ca), characterized by both anti-bacterial and anti-corrosion attributes. These coatings were synthesized by integrating surface groups of magnesium hydroxide/magnesium oxide with surface atoms of nano‑silicon dioxide (nano-SiO2) particles, leading to the formation of magnesium silicate junctions. Subsequently, these interfacial surfaces were functionalized using organofluorosilanes. With the application of the coating, a notable enhancement in the static contact angle of water from 43.7° ± 1.1° to 158.4° ± 1.3° was observed. The anti-adhesive properties of the coating against bacteria were assessed through inoculation assays with Staphylococcus aureus, a predominant agent of implant-associated infections. No bacterial colonization on the Mg4Zn0.5Ca alloy surface was detected when the dual-functional coatings were applied. While a hydrogen evolution (HE) of 4.78 mL/cm2 was measured on uncoated surfaces, the HE reduced significantly to 0.35 mL/cm2 for coated alloy surfaces. Analysis using Nyquist plots unveiled a polarization resistance of coated surfaces that was an order of magnitude higher than uncoated surfaces. As a result, Mg alloys covered with a dual-functional nanocoating layer demonstrate favorable characteristics, such as diminished corrosion rates and enhanced resistance against bacterial adhesion. Such coatings negate the necessity for subsequent surgical removal of bone implants, consequently mitigating potential bacterial infections and the concomitant medical expenses.

Optimization of fungicidal and acaricidal metabolite production by endophytic fungus Aspergillus sp. SPH2

The endophytic fungus Aspergillus sp. SPH2 was isolated from the stems of the endemic plant Bethencourtia palmensis and its extracts were found to have strong fungicidal effects against Botrytis cinerea and ixodicidal effects against Hyalomma lusitanicum at different fermentation times. In this study, the fungus was grown using three different culture media and two methodologies, Microparticulate Enhancement Cultivation (MPEC) and Semi-Solid-State Fermentation (Semi-SSF), to increase the production of secondary metabolites during submerged fermentation. The addition of an inert support to the culture medium (Semi-SSF) resulted in a significant increase in the extract production. However, when talcum powder was added to different culture media, unexpected results were observed, with a decrease in the production of the biocompounds of interest. Metabolomic analyses showed that the production of aspergillic, neoaspergillic, and neohydroxyaspergillic acids peaked in the first few days of fermentation, with notable differences observed among the methodologies and culture media. Mellein production was particularly affected by the addition of an inert support to the culture medium. These results highlight the importance of surface properties and morphology of spores and mycelia during fermentation by this fungal species.Graphical

An environmentally friendly strategy for reducing the environmental risks of heavy metals adsorbed by kaolinite

Plenty of heavy metals (HMs) that are adsorbed on clay minerals (such as kaolinite), in addition to low molecular-weight organic acids (such as oxalic acid (OA)) with high activities, are widespread in the natural environment. In the present study, the effects of OA on the environmental behaviors of Pb2+/Cd2+ adsorbed by kaolinite have been investigated. The effectiveness and mechanisms of calcium silicate (CS) and magnesium silicate (MS) in reducing the environmental risks of the HMs have also been studied. The results showed that the releases of Pb2+/Cd2+ increased with an increasing concentration of OA. When different dosages of CS/MS were added to the aging system, a redistribution of HMs took place and the free form of Pb2+/Cd2+ decreased to very low levels. Also, the unextractable Pb2+/Cd2+ increased to high levels. Furthermore, a series of characterizations showed that the released HMs were re-captured by the CS/MS. In addition, the CS immobilized the OA in the solution during the aging process, which also facilitated an immobilization of the carbon element in the environment. In general, the present study has contributed to a further understanding of the transport behaviors of the HMs in natural environments, and of the interactions between CS (or MS), the environmental media, and the heavy metal contaminants. In addition, this study has also provided an eco-friendly strategy for an effective remediation of heavy metal pollution.

Talcum powder coated polydimethylsiloxane (PDMS) film flexible large-deformation separation system and stable forming process in bottom-up ceramic vat photopolymerization

In the bottom-up vat photopolymerization process for ceramic materials, the as-built part is generated layer-by-layer from the bottom of the slurry vat. The separation process between the solidified layer and the bottom of the slurry vat introduces significant vertical separation forces due to various resistance forces. Particularly in fabricating large cross-section parts, larger separation forces are more prone to induce crack propagation or detachment of the as-built part from the substrate, resulting in printing failures. This study introduces a novel approach involving the application of a talcum powder-coated polydimethylsiloxane (PDMS) film to address this issue, aiming to reduce the adhesion between the PDMS film and the bottom of the slurry vat. The developed system exhibits flexible separation capabilities during the build platform's lifting process. Compared to traditional unmodified PDMS film separation systems, the modified system demonstrates an average reduction of 93% in the maximum separation force. Notably, as the cross-sectional area of the printing increases, the magnitude of the increase in maximum separation force of the modified system compared to the unmodified system drops significantly. This characteristic facilitates the successful printing of larger-sized parts. The talcum powder-coated PDMS separation system proves effective in successfully printing aviation ceramic cores, triply periodic minimal surface (TPMS) models, teeth model with a cross-sectional size of 85 mm × 65 mm in solid geometry and a bone model exceeding 150 mm in height.