Formulation of Geopolymer Cements from Two Clays Containing Kaolinite and Muscovite: Effect of Temperature on the Physicomechanical Properties of the Products

The paper talks about the elaboration of geopolymer with two types of kaolinite clays containing muscovite. The kaolinite materials were first calcined at different temperatures, and mixed with an activator solution, called liquid precursor, at a different solid/liquid mass ratio depending on their normal consistency to produce geopolymer binders. Results show that the geopolymer products obtained from the different clays have good physichomechanical properties: their open porosity and their water absorption rate decrease while their compressive strength and their apparent density increase with the increase in calcination temperature of the clays. The density of GABD binders varies between 2.92 and 2.47 g/cm3 and that of GARD binders between 1.86 and 2.16 g/cm3. Specimens in the GABD series have the best mechanical performance, ranging from 14.43 to 31.37 MPa, while those in the GARD series oscillate between 6.18 and 11.56 MPa. These properties make kaolinite materials from this region suitable for use as construction materials for adequate waterproof structures.

Modified calcination conditions of rare alkali metal Rb-containing muscovite(KAl_2[AlSi_3O_(10)](OH)_2)

Muscovite mineral was roasted in different conditions.Rubidium leaching rate was a standard to examine the impact of various factors on calcination effect,including the agent types,roasting time,mass ratio,and roasting temperature.The results indicate that the best agent is the combination of sodium chloride and calcium chloride,and its mass ratio of muscovite/NaCl/CaCl2is1.00:0.25:0.25.Calcined at 850℃ for 30 min,the rubidium leaching rate is up to 90.12%.The reaction of muscovite ore with the chlorinating agent CaCl2was studied by TG/DSC,and the surface morphology before and after leaching was characterized by SEM.Rubidium chloride products can be obtained using t-BAMBP extraction,hydrochloric acid re-extraction,and purification.

Muscovite nanoparticles mitigate neuropathic pain by modulating the inflammatory response and neuroglial activation in the spinal cord

Despite numerous efforts to overcome neuropathic pain,various pharmacological drugs often fail to meet the needs and have many side effects.Muscovite is an aluminosilicate mineral that has been reported to have an anti-inflammatory effect,but the efficacy of muscovite for neuropathic pain has not been investigated.Here,we assessed whether muscovite nanoparticles can reduce the symptoms of pain by controlling the inflammatory process observed in neuropathic pain.The analgesic effects of muscovite nanoparticles were explored using partial sciatic nerve ligation model of neuropathic pain,in which one-third to onehalf of the nerve trifurcation of the sciatic nerve was tightly tied to the dorsal side.Muscovite nanoparticles(4 mg/100μL)was given intramuscularly to evaluate its effects on neuropathic pain(3 days per week for 4 weeks).The results showed that the muscovite nanoparticle injections significantly alleviated partial sciatic nerve ligation-induced mechanical and cold allodynia.In the spinal cord,the muscovite nanoparticle injections exhibited inhibitory effects on astrocyte and microglia activation and reduced the expression of pro-inflammatory cytokines,such as interleukin-1β,tumor necrosis factor-α,interleiukin-6 and monocyte chemoattractant protein-1,which were upregulated in the partial sciatic nerve ligation model.Moreover,the muscovite nanoparticle injections resulted in a decrease in activating transcription factor 3,a neuronal injury marker,in the sciatic nerve.These results suggest that the analgesic effects of muscovite nanoparticle on partial sciatic nerve ligation-induced neuropathic pain may result from inhibiting activation of astrocytes and microglia as well as pro-inflammatory cytokines.We propose that muscovite nanoparticle is a potential anti-nociceptive candidate for neuropathic pain.All experimental protocols in this study were approved by the Institutional Animal Ethics Committee(IACUC)at Dongguk University,South Korea(approval No.2017-022-1)on September 28,2017.

Muscovite 40Ar-39Ar age and its geological significance in Zhuxi W（Cu） deposit, northeastern Jiangxi

The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and the Late Paleozoic carbonate rocks.Three types of mineralization including skarn type,altered granite type and quartz vein veinlet type orebodies have been observed.In this study,the 40Ar 39Ar age of hydrothermal muscovite coexisting with copper mineralization in the altered granite type orebody formed near the unconformity interface is determined by step-heating technology using CO2 laser.The plateau age,isochron age,and inverse isochron age of muscovite are(147.39±0.94)Ma,(147.2±1.5)Ma,and(147.1±1.5)Ma,respectively.These ages are almost identical to the ages of ore-related granite and other mineralization types in the Zhuxi W(Cu)deposit,indicating that the Cu mineralizations occurred at the shallow depth and near the unconformity interface are contemporaneous during the Late Jurassic.This further suggested that the acompanied W and Cu mineralization in the Zhuxi W(Cu)deposit which may be controlled by the magma source is enriched in both W and Cu.

Mechanism of separating muscovite and quartz by flotation

Flotation experiments were performed to investigate the separation of muscovite and quartz in the presence of dodecylamine(DDA), tallow amine(TTA) and dodecyltrimethylammonium bromide(DTAC). The adsorption mechanisms of these three kinds of amines on muscovite and quartz were studied by FT-IR spectrum analysis, contact angle measurement and molecular dynamics(MD) simulation. The results reveal that the separation of muscovite from quartz is feasible at strong acid pulp condition using amine collectors. TTA and DTAC show poorer collecting ability for flotation of the two minerals compared with DDA. Physical adsorption is found to be the main adsorption module of amine collectors on muscovite and quartz by FT-IR analysis. MD simulation results show a strong physical adsorption ability of DDA+ cation on muscovite and quartz(muscovite(001):-117.31 kJ/mol, quartz(100):-89.43 kJ/mol), while neutral DDA molecular can hardly absorb onto the surface of these two minerals. These findings provide a novel explanation for the flotation mechanism from the perspective of MD simulation.

Preparation and Tribological Properties of Lanthanum-doped Muscovite Composite Particles as Lubricant Additives in Lithium Grease

Lanthanum-doped muscovite(MC) composite particles(hereinafter abbreviated as La-MC) were prepared by the mechanical solid-state-chemistry-reaction method, followed by surface modification with oleic acid. The microstructure of materials was characterized by SEM, XRD, EDS and FTIR. Furthermore, the friction-reduction and anti-wear properties of MC and La-MC as lubricant additives in lithium grease were evaluated using a four-ball friction and wear tester. The results showed that La(OH)_3 nanoparticles were coated on the surface of muscovite. Both MC and La-MC can effectively improve the friction-reduction and anti-wear properties of lithium grease and La-MC presents better tribological properties than MC. The excellent tribological properties of La-MC can be attributed to the formation of the adsorbed La-MC film and the chemical reaction film mainly composed of Fe_2O_3 and SiO_2 on the worn surface, as well as the catalysis of lanthanum element during the friction process.

Potassium recovery from muscovite using NaCl-roasting followed by H_(2)SO_(4)-leaching

The present study aims at the recovery of potassium from muscovite mica(which contains K_(2)O;~10 wt%)using NaCl-roasting coupled with H_(2)SO_(4)-leaching process.The preliminary acid leaching studies applying different mineral acids resulted in a potassium recovery of 8%−18%.The optimum leaching conditions for the maximum recovery were 4 mol/L H_(2)SO_(4),60 min leaching time and liquid-solid ratio 4 mL/g at 90℃.However,the roasting of muscovite with additive NaCl(muscovite:NaCl mass ratio of 1:1.00,900℃,45 min)followed by H_(2)SO_(4)-leaching(95℃,60 min)extracted potassium to the tune of 98%.Under similar roasting conditions,the H_(2)O-leaching process extracted only 60%of potassium.The effects of various roasting and leaching parameters such as temperature,time,NaCl concentration,acid concentration,liquid-solid ratio on potassium extraction were evaluated.The appearance of the sylvite(KCl)mineral phase in the NaCl-roasted muscovite and its disappearance in the acid/water leached residue confirmed the physical and chemical distortions of the muscovite crystal structure.The possible mechanism of potassium release from the complex muscovite structure was elucidated based on available literature substantiated by characterizations using X-ray diffraction(XRD)and scanning electron microscopy with energy dispersive X-rays spectroscopy(SEM-EDX).

Generation of Muscovite/ Two-Mica Granil and Intracontinental Subduction

This paper discusses generahon of muscovite/ two-mica granite and their genetic relations to intracontinental subduchon. The major constraints of the formation of muscovite granite,taking Higher Himalaya for an example, are demostrated from multiple-aspects of geology,petrology, geochemistry, experimental petrology and geophysics .We suggest that the magma generates in the Main Central Thrust (Mad ) (30-35km ), and has higher temperature of 750-800℃, H2O-undersatorated and large capability to be emplacement into the sedimentary covers to form real igneous intrusion, rather than generster at the base of the thickened continental crust and has lower temperature of 600-650 ℃, H2O-saturated and less capability of emplacement to form intrusion in silo/semi-situ. A reasonable model of thermal structure of the intracontinental subduction zone is presented. Combining the possible material of magma source and the experimental phase relatioedps, we demonstrate in detail that the main magma source of the muscovite granitc is the pelitic rocks at top of the subduedon slab at the adjacent region of the subduction end. In addition, the H2O-saturate and wear saturated granitic magmas are formed at the wedge comer of the overlying slab. A new conclusion is reached that the generation Of muscovite granite is a result of the intracontinental subduction, in other words,the development of muscovite granite is a main signature to recognize the indacontinental subduction zone.

Mechanical and Thermal Properties of Muscovite and Density Polyethylene-reinforced and–toughened Polypropylene Composites

The mechanical and thermal properties of polypropylene （PP）/muscovite/ low-density polyethylene （LDPE）/ polypropylenegraftmaleic anhydride （PP-g-MAH） ternary composites were investigated. In PP matrix, muscovite, LDPE, and PP-g-MAH were added as strengthening agent, toughening agent, and compatibilizer, respectively. The effects of dosages of the added materials were analyzed. The - experimental results show that the optimum recipe of PP/muscovite/LDPE/PP-g-MAH composites is 100/10/6/20 （mass ratio）. Compared with the pure PP, the mechanical properties of PP/muscovite/LDPE/PP-g-MAH composites, including notched impact strength, Rockwell hardness and flexural strength, are improved. Although tensile strength is slightly decreased, they have better toughness. Filled with muscovite, the heat-resistance and heat-decompostion of the composites are improved.

Muscovite is protective against non-steroidal anti-inflammatory drug-induced small bowel injury

AIM: To evaluate the effect of muscovite in preventing small bowel injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs).

Infl uencing Mechanism and Interaction of Muscovite on Thermal Decomposition of Ammonium Polyphosphate

The interaction mechanism and phase evolution of ammonium polyphosphate（APP）mixed with muscovite（APP/muscovite）were studied by TG,XRD and SEM,respectively,during heating.When the temperature is not higher than 300 ℃,muscovite has no effect on the thermaldecomposition of APP,and the initialdecomposition temperature of APP/muscovite at 283 ℃ is basically the same as the APP at 295 ℃,and the main thermaldecomposition products are polyphosphoric acid and NH_4H_2PO_4 at 300 ℃.The polyphosphoric acid,the decomposition products of APP,can enable K and Siout of muscovite and interact with muscovite chemically to generate Al_2O_3·2SiO_2,α-SiO_2 and phosphates（AlPO_4 and K_5P_3O_（10））compounds during 400 ℃-800 ℃,which own obvious adhesive phenomenon and porous structure with the apparent porosity of 58.4%.Further reactions between phosphates other than reactions among Al_2O_3·2SiO_2 and α-SiO_2 can generate KAlP_2O_7 at 1 000 ℃ and the density of residualproduct is improved by low melting point phosphate filling pore to form relatively dense structure and decrease the apparent porosity to 44.4%.The flame resistant and self-supported ceramic materials are expected to enhance the fire-retarding synergistic effect between APP and muscovite.

Properties and Structure of Microcrystal Muscovite Composite Superabsorbent

Microcrystal muscovite composite superabsorbents（MMCSA） were prepared by water solution polymerization using acrylic acid, acrylamide and itaconic acid as comonomers and microcrystal muscovite as an inorganic additive. Properties, such as water absorbency, salt absorbency, gel strength, water retention capacity and structure of MMCSA characterized by SEM and XRD, were investigated. Water absorbency, salt absorbency, gel strength, water retention capacity and thermostability were enhanced by incorporation of suitable amount of microcrystal muscovite. Water absorption of MMCSA was rapid, requiring 24.55 min to reach 63% of equilibrium absorbency（1218 g/g）. Microcrystal muscovite was physically combined into the polymeric network without destroying its polycrystalline structure and microcrystal muscovite composite superabsorbent had some irregular, undulant, and small microporous holes with sheet-like microcrystal muscovite distributed in the polymeric matrix.

Effect of doping concentration on the performance of solar cell constructed from (Muscovite/TiO₂/Dye/Al)

Solar cells were fabricated from (Muscovite/ TiO2/Dye/Al), the effect of temperature, concen- tration and light intensity on the electrical prop- erties of (Muscovite/TiO2/Dye/Al) was studied. The relationship between current and voltage was found to be algorism, which is in agreement with the ordinary relation for solar cells. When dye concentration was increased the conductivity, fill factor and efficiency were also increased. This result is found to be in conformity with the theoretical relations. The small energy gaps for their samples show that they are semiconductors. The maximum efficiency obtained is 33.2%.

Effect of Radioactive Minerals Potentiality and Primordial Nuclei Distribution on Radiation Exposure Levels within Muscovite Granite, Wadi Nugrus, Southeastern Desert, Egypt

The studied area at Wadi Nugrus, Southeastern Desert, Egypt, is located between lat. 24°41'00'' and 24°41'35''N and long. 34°36'47'' and 34°37'09''E. The rock types are represented by layered metagabbros, biotite schists, gneisses, granodiorites, and Muscovite granites. The muscovite granite of Wadi Nugrus, is small exposure in size (~5.0 km2), emplaced along NW-SE trend, with about 0.5 - 4.5 Km in length and 100 - 250 m in width and intruding the biotite schists. The studied muscovite granite is composed mainly of plagioclases, potash feldspars, quartz, biotite and muscovite. The recorded minerals assemblage can be classified into secondary U-minerals (uranophane and meta-autunite), U-bearing minerals (uranothorite and columbite) and accessory minerals (zircon, flourite, allanite, zinnwaldite and hematite). The U/eU is more unity where, the measured chemical uranium is higher than the measured equivalent uranium in the most analyzed samples especially in trenches, which reflect disequilibrium state. The activity concentrations range from 251.72 to 1096.2 Bq·kg-1 for 232Th, from 494 to 2593.5 Bq·kg-1 for 226Ra, and from 1314.6 to 1846.7 Bq·kg-1 for 40K. The obtained radiological data show that the average internal and external hazard indices are 9.11 and 5.78, respectively which are more than unity and highly exceeding the permissible limits (International Commission on Radiation Protection, ICRP). The internal and external hazards are mainly due to 226Ra nuclei while the absorbed dose rate (nGy/h) is related to 232Th nuclei. The contributions of the three nuclei in the total absorbed dose rates and internal and external hazardous, for 226Ra, it contributes by 72% in Hin, 57% in Hex and 55% of DR, for 232Th it contributes by 24% in Hin, 37% in Hex and 36.9% of DR, while for 40K it contributes by 4.1% in Hin, 6.4% in Hex and 8.1% of DR.

Method for grinding and delaminating muscovite

A method of dry grinding muscovite based on the use of knife-mills is reported.It was possible to produce mica with a particle size below 100 and 45μm.After grinding,the samples were submitted to sonication treatment,which promoted delamination of the material.The particle size distribution shows that sonicated mica has more particles in the size range 10-50μm than does non-sonicated mica have. This also indicates a decrease in the average particle size.Characterization of the treated muscovite by scanning electron microscopy revealed a highly delaminated material with a plate-like structure.The products were characterized by chemical analysis and X-ray diffraction,too.This mica has already been used for the synthesis of pearlescent pigments.

Structural modification in swift heavy ion irradiated muscovite mica

Two-layer monoclinic （2M） muscovite mica sheets with a thickness of 12 μm are irradiated with Sn ions at room temperature with electronic energy loss （dE/dx）e of 14.7 keV/nm. The ion fiuence is varied between 1 ×10^11 and 1 ×10^13 ions/cm^2. Structural transition in irradiated mica is investigated by x-ray diffraction （XRD）. The main diffraction peaks shift to the high angles, and the inter-planar distance decreases due to swift heavy ion （SHI） irradiation. Dehydration takes place in mica during SHI irradiation and mica with one-layer monoclinic （1M） structure is thought to be generated in 2M mica after SHI irradiation. In addition, micro stress and damage cross section in irradiated mica are analyzed according to XRD data. High resolution transmission electron microscopy （HRTEM） is used on the irradiated mica to obtain the detailed information about the latent tracks and structural modifications directly. The latent track in mica presents an amorphous zone surrounded by strain contrast shell, which is associated with the residual stress in irradiated mica.

Synthesis and Swelling Behaviors of Microcrystal Muscovite Composite Superabsorbent by Photopolymerization

A new microcrystal muscovite composite superabsorbent was synthesized by UV photopolymerization using 2-hydroxy-2-methylpropiophenone（1 173） as photoinitiator,N,N-methylene bisacrylamide（MBA） as crosslinker,acrylic acid（AA）,acrylamide（AM） and sodium 4-styrenesulfonate（SSS） as comonomers.Factors affecting water and salt absorption of the microcrystal muscovite composite superabsorbent,such as crosslinker amount,microcrystal muscovite concentration,photoinitiator content,and SSS concentration,were systematically studied.Water retention capacity of the composite superabsorbent was also investigated.The results show that microcrystal muscovite composite superabsorbent has water absorbency of 550 g/g,salt absorbency of 62 g/g,and water retention of 60% after heating at 70 ℃ for 40 h.The microcrystal muscovite is physically combined into the polymeric network without destroying its polycrystalline structure and the surface of the microcrystal muscovite composite superabsorbent has some deep and small holes.

Geochronology,geochemistry and geodynamics implications of Middle Triassic garnet-bearing muscovite monzogranite in central Jilin Province

Zircon LA-ICP-MS U-Pb geochronology and geochemical analyses are undertaken for the garnet-bear-ing muscovite monzogranite in Yitong area, central Jilin Province. The formation age and petrogenesis of the granite are determined, and the regional tectonic background is discussed. Zircons from the granite are euhe-dral-subhedral in shape, and display fine-scale oscillatory growth zoning, indicating a magmatie origin. LA- ICP-MS zircon U-Pb dating result indicates that the garnet-bearing muscovite monzogranites formed in the mid-dle Triassic （243 Ma ）. The garnet-bearing muscovite monzogranites have high SiO2 （SiO2 = 74.1%- 76.49% ）, rich aluminum （A1203 = 14.47%-14.68% ） and alkali （ NazO ＋ K20 = 4.31%-7.9% ）, low Fe203T and MgO （MgO =0.1%-0. 13% , Fe203T =0.46%-1.02% ）. The ratio of CaO/Na20 is between 0.17--0. 21. The garnet-bearing muscovite monzogranites in Yitong region are relatively enriched in light rare earth elements （LREEs） and large ion lithophile elements （LILEs） , and depleted of heavy rare earth elements （HREEs） and high field strength elements （HFSEs）. They are characterized by high Sr and Ba, poor Rb and Y, and negative Eu abnormally （δEu =0.48-0.62） , with Rb/Sr 〈 1. The εHf（t） values and TDM2 of zircons range from ＋ 6. 10 to ＋ 8.00 and from 725 Ma to 814 Ma, respectively. The above features indicate that gar- net-bearing muscovite monzogranites in Yitong area were derived from partial melting of metasedimentary rock. These granites have high Sr/Y ratios, which suggest they formed in a thickened continental crust. Combined with the coeval granitic rocks in central Jilin Province, we suggested that a significant eollisional and thickening event took place during the Middle Triassic.

3-18 Investigations of Latent Track and Vibrational Spectra of Muscovite Mica Irradiated by Swift Heavy Ions

Muscovite mica sheets with a thickness of 12 m were irradiated by swift heavy ions Kr and Bi from Heavy IonResearch Facility in Lanzhou(HIRFL). The uences range from 11010 to 11012 ions/cm2. The electronic energyloss (dE/dx)e increases from 5.9 to 31.5 keV/nm. The vibrational modi cations in irradiated mica were investigatedby Fourier-transform infrared spectroscopy and the latent tracks were observed by transmission electron microscope(TEM). The infrared spectrum shows that motions from all atom types in the muscovite mica structure could befound in modes for all vibrations. As shown in Fig. 1, the intensity of all vibrational modes in mica, including theOH stretch motion at 3621 cm??1, decreased with the increasing (dE/dx)e. The similar tendency is found in samplesirradiated by swift heavy ions with increasing ion uence. It is indicated that defects and structural modi cationsgenerated during swift heavy ion irradiation, and more defects are introduced by irradiation with higher ion uence.

Mineralogical feature and geological significance of muscovites from the Longyuanba Indosinian and Yanshannian two-mica granites in the eastern Nanling Range

Emplacement P-T condition estimations using granites are important for understanding metamorphic and erosional processes of orogenic belt.Granites are widespread in South China and a majority of them are peraluminous.Particularly,over 91%of the Indosinian granites exposed in the region are peraluminous in composition.It is extremely hard to determine the pressure of intrusion of these peraluminous granites due to the absence of amphibole,a good mineral barometer commonly identified in metaluminous granites.Muscovite is a common mineral in peraluminous granites,certain kind of it could be used as a mineral barometer to constrain the emplacement pressure of peraluminous granites.In this paper,results of petrographic and geochemical studies of muscovites from the Indosinian and early Yanshanian two-mica granites at the Longyuanba in the eastern Nanling Range are reported.Based on petrographic studies,the primary muscovite can be discriminated from the secondary muscovites.Muscovites from the Indosinian two-mica granites are enriched in Ti,Al,Mg,and Na,and depleted in Fe and Mn.Geochemically,these muscovites were considered as primary,whereas those from the Yanshanian two-mica granites fall into the area of secondary muscovite on discrimination diagrams.Barometer estimations show that pressures calculated for primary muscovites are accurate,but those calculated for secondary muscovites are overestimated.The average pressure of emplacement of the Longyuanba Indosinian two-mica granites is 5.9 kbar,corresponding to^19 km in depth,suggesting that the Indosinian granitic magmas were probably generated by partial melting of a thickened crust root in a compressional tectonic setting.