Abstract:In this study, the authors utilized infrared emission spectroscopy to investigate the infrared emission spectrum characteristics of a kind of natural carbonate and primary phase compositions, highlighting the radiation mechanism of carbonate rock. X-ray diffraction (XRD) and Raman spectroscopy results indicate that micro-nanoscale dolomite (70%), calcite (25%) and quartz (5%) are the primary phase compositions, with a small amount of iron manganese oxide. On the basis of blackbody radiation theory and the radiation energy spectra of samples from 400 to 2 000 cm^-1 at 80℃, the corresponding emissivity of this rock, pure dolomite, calcite and quartz are calculated as 1.010, 1.000, 0.997 and 0.958, respectively. Notably, the radiation energy spectrum calculated by emissivity and emission spectrum of dolomite shows high consistency with that of the natural carbonate at the same temperature, indicating that the radiation performance of the rock is mainly attributed to dolomite. Within the temperature and wavelength of this study, the heat capacity values of above minerals are the function of temperature and exhibit a positive correlation with infrared emissivity, and the highest heat capacity of dolomite benefits the enhancement of the whole thermal radiation performance of carbonate rock. The diameter of the mineral particles has a certain influence on the propagation of thermal radiation. When the diameter of particles is close to radiation wavelength, the attenuation of thermal radiation would decrease emissivity. The vibration of C-O and Si-O bonds in the narrow absorption band of emission spectrum (1 350~1 500 cm^-1 and 950~1 275 cm^-1) would lead to relatively high radiation energy and emissivity. This study can provide theoretical reference for infrared radiation material, i.e., using the rich and cheap natural minerals on the earth as a source of raw materials for infrared functional materials.

Abstract:The Weichang area in Hebei Province has plenty of natural zeolite resources. However, limited researches have been paid to this zeolite. In this paper, such means as XRD, XRF, FTIR, specific surface area and pore size distribution analyzer and SEM-EDS were employed to analyze the mineralogical characteristics of the natural zeolite. Benzene, methylbenzene and water vapor were used to evaluate the adsorption property of the natural zeolite. The results showed that the natural zeolite consisted of clinoptilolite and quartz and the SiO₂/Al₂O₃ ratio was 5.3. The natural zeolite had relatively high specific surface area (27.67 m²/g), a few micropores and plenty of mesopores. The zeolite exhibited good adsorption property on benzene, methylbenzene and water vapor. The maximum adsorption capacity and equilibrium time for benzene and methylbenzene were 1 309.29 mg/g and 1 101.96 mg/g, 240 min and 300 min, respectively. The adsorption systems for benzene and methylbenzene obeyed the pseudo-second-order kinetic model, and Freundlich model could fit the isotherm well. The water vapor adsorption per unit area on the natural zeolite was 0.935 8 mg/m² under 70% humidity at 30℃ for two days of adsorption.

Abstract:At low temperature of 4℃,the inorganic origin of monohydrocalcite (MHC) in Lake Nam Co was investigated by simulating the mainly ionic species and controlling the Mg/Ca ratio in the reaction system. The experimental result indicates that MHC is transformed from amorphous calcium carbonate (ACC), and the formation and stability of MHC are regulated by Mg²⁺ in the reaction solution. When Mg/Ca ratio<2 in the reaction solution, calcite and magnesian calcite are formed, and when Mg/Ca ratio>2 in the solution, MHC is formed, and the existence time in the solution increases with the Mg/Ca ratio. In the case of Mg/Ca ratio being 2, MHC exists in the solution for 48 h, then it transforms to aragonite and a small amount of magnesian calcite. The effect of Mg²⁺ in the formation of MHC lies mainly in inhibiting the nucleation of calcite, so that MHC can be formed and stable in the solution. The results could provide a certain basis for the study of inorganic origin of the MHC in Lake Nam Co.

Abstract:Using sodium-based montmorillonite as raw material and based on the potentiometric titration curve and characteristic critical point, the authors divided the transformation of Al³⁺ into four morphologies, and prepared the corresponding montmorillonite. X-ray diffraction, infrared spectroscopy and thermal analysis were used. The microstructure and thermal stability of pillared montmorillonite were studied. The results show that the d₍₀₀₁₎ value of pillared montmorillonite layer spacing in zone Ⅲ increases from 12.408 1 to 18.317 5 nm. Meanwhile, the strength of the Si-O stretching vibration peak of pillared montmorillonite in zone Ⅲ decreases obviously. The dehydroxylation reaction of octahedral structure of talc shifts to low temperature zone compared with that of original ore, which indicates that pillared montmorillonite in zone Ⅲ has bonding reaction and the pillared effect is the best.

Abstract:In this study, the reductive transformations of 2-nitrophenol (2-NP) by interfacial complex systems of Fe(Ⅱ) associated with kaolinite and montmorillonite respectively were systematically investigated. The results showed that surface-bonded Fe(Ⅱ) species on the minerals can effectively improve the rate of reductive transformations. The reduction reactions of 2-NP over the complex systems can be described by the pseudo first-order kinetics. The rate constant (k) was increased with the pH, initial Fe(Ⅱ) concentration and reaction temperature. Moreover, 2-NP removal efficiency can reach 100% within 4.0 h by the presence of Fe(Ⅱ)/kaolinite system under the conditions of pH 6.7 and temperature 25℃, initial concentrations of 3.0 mmol/L Fe(Ⅱ) and 0.022 mmol/L 2-NP as well as the dose of kaolinite at 4.0 g/L. Similarly, when the solution pH increased from 6.0 to 7.3, the transformation for 2-NP removal was also clearly enhanced by the presence of Fe(Ⅱ)/montmorillonite system, but the conditions with a lower pH and a lower initial Fe(Ⅱ) concentration were quite not favorable for montmorillonite to effectively catalyze 2-NP to be reduced by Fe(Ⅱ), and the performance was even lower than that of kaolinite. This may be ascribed to montmorillonite having a higher cation-exchange capacity. Therefore, the difference in speciation of adsorbed Fe(Ⅱ) is the intrinsic reason for controling the 2-NP reductive transformation in the mentioned mineral interfacial reduction systems.

Abstract:In this paper, the authors studied the effect of AlPO₄ content on the formation of iron minerals in the cultures of A. ferrooxidans HX3, and characterized and analyzed the structures of the obtained corresponding precipitate products. The results showed that the addition of AlPO₄ had little effect on Fe²⁺ oxidation during bacterial cultivation, but it could promote Fe³⁺ hydrolysis and formation of the initial iron mineral phase and accelerate transformation of jarosite. Under the higher Al/Fe mole rates of 0.04~1, schwertmannite and jarosite could be formed. Also, iron phosphate could be formed in cultures with Al/Fe mole rates of 0.4 and 1. The higher Al/Fe mole rate and phosphate content are conducive to the formation of iron phosphate.

Abstract:In this paper, the heterogeneous reactions of H₂O₂ and SO₂ on the surface of mineral oxides (α-Fe₂O₃) were simulated by density functional theory. The adsorption mechanism and oxidation mechanism of H₂O₂ and SO₂ on the surface of α-Fe₂O₃ (001) were studied. The results showed that both SO₂ and H₂O₂ were adsorbed by Fe atoms on the surface of α-Fe₂O₃ (001). Compared with SO₂, H₂O₂ adsorbs preferentially on the surface of α-Fe₂O₃ (001), and the forms of H₂O₂ on the surface tend to be two ·OH forms. Through the analysis of the local density of states, differential charge density and Mulliken charge distribution, it was found that the co-adsorption of SO₂ and H₂O₂ was in the form of ·OH generated by H₂O₂ adsorbed on the surface of α-Fe₂O₃ (001), while SO₂ was oxidized by ·OH[S_(SO2) -charge distribution:0.79 e→1.32 e; O_(H2O2)-charge distribution:-0.77 e→-1.11 e], and ·OH+SO₂ clusters were formed. These data show that the atmospheric trace gas H₂O₂ can mediate the adsorption of SO₂ on the surface of mineral oxides and promote the transformation of SO₂. The results obtained by the authors provide a theoretical basis for understanding the heterogeneous oxidation of SO₂ by trace H₂O₂ in the atmosphere.

Abstract:The eutrophication is closely related to the accumulation of phosphorus in surface water. Therefore, the removal of dissolved phosphorus in water is the key to reducing the risk of eutrophication. In the past 10 years, the utilization of rare earth elements as an agent for sewage dephosphorization has achieved good results. In this study, the capability of eight crystalline rare earth oxides (Y₂O₃, La₂O₃, CeO₂, Pr₆O₁₁, Nd₂O₃, Sm₂O₃, Eu₂O₃ and Dy₂O₃) for removing phosphorus was detected. The results show that La₂O₃ has the best phosphorus removal performance, followed by Pr₆O₁₁, Y₂O₃, Eu₂O₃, Nd₂O₃. Sm₂O₃ and Dy₂O₃ have weak effects. CeO₂ has no phosphorus removal capability at all. The kinetic behavior of phosphorus adsorption on the surface of rare earth oxides is more in line with the quasi-first-order reaction model. The adsorption isotherm is consistent with the Langmuir model. The experiment reflects the alteration of rare earth oxides after phosphorus removal and the variance of pH value in the liquid during the process of phosphorus removal. It is believed that the dephosphorization of using the rare earth oxide to remove phosphorus is mainly by adsorption. The precipitation induced by the dissolution of oxides also plays a role. In order to avoid the declining of the surface adsorption capacity caused by agglomerate of the rare earth oxides in the water, the authors loaded the micro-nano particles of the La₂O₃ on the surface of different clay minerals. This design has significantly improved the phosphorus removal capability of the rare earth oxides. The amount of absorbed phosphorus was increased by approximately 25%. The phosphorus removal performance of the three clay minerals with the same amount of La₂O₃ was not significant. The improvement of rare earth oxide particle dispersion by clay minerals might be the main reason for increasing the phosphorus removal capability.

Abstract:In this study, the heavy metal contaminated soils were prepared by adding a certain amount of copper, nickel and cadmium salts. The bentonite and tetraethylenepentamine modified bentonite (amino-bentonite) were added to the prepared soils as repair agents, and then available heavy metals were extracted by simulated acid rain and mixed extractant. The extraction rate of heavy metals in each contaminated soil was below 0.1% by simulated acid rain with pH of 3.5. The extraction capability of the mixed extractant for the available heavy metals in the contaminated soil was much stronger than that of the simulated acid rain. Adding bentonite and amino-bentonite could passivate copper, nickel and cadmium in soils. The amino-bentonite had stronger passivation capability for copper, nickel and cadmium than bentonite, because there was complexation between the grafted amino group on the amino-bentonite and the metals. The comprehensive evaluation shows that amino-bentonite is a passivation material with application prospects for copper, nickel and cadmium contaminated soils.

Abstract:Sulfide semiconductor minerals are widely distributed in the earth crust. Some of the sulfide minerals with narrow band gaps, such as pyrite, chalcopyrite, and pyrrhotite, can generate natural thermoelectric potential to convert the thermal energy within the earth to electrical energy under the geothermal gradient. In this paper, the authors selected natural sulfide mineral samples such as pyrite, pyrrhotite, galena, chalcopyrite, bornite and bornite-chalcocite-hematite mineral assemblage to study their thermoelectric properties. The results indicated that, at the temperature of 300~700 K, except that the pyrrhotite exhibited electrical transmission of metal conductors with low Seebeck coefficient and ultra-high conductivity, pyrite and chalcopyrite samples were n-type semiconductors, while bonite and the bornite-chalcocite-hematite mineral assemblage sample were p-type semiconductors, which exhibited significant Seebeck coefficient of 150~500 μV/K and a conductivity of 5~95 S/cm, indicating that samples had the capability for producing significant thermoelectric effects under geothermal gradients. Thermal conductivity was calculated based on thermal diffusivity measured by laser flash diffusivity method, theoretical specific heat capacity and density of the sample, and the results of the thermal conductivity showed that bornite and the sulfide mineral assemblage samples exhibited low thermal conductivity less than 1 W/(m ·K), indicating that the samples could form a large temperature difference under the influence of local heat source. According to the basic theory of thermoelectricity and the geothermal gradient, the authors constructed the natural thermoelectric effect model to calculate the natural thermoelectric potential, additional surface current density and thermoelectric conversion efficiency generated by the sulfide semiconductor minerals, where empirical formulas were summarized. It is found that sulfide minerals can produce a natural thermoelectric potential of about 100 mV at 300~650 K, and the maximum thermoelectric conversion rate can reach 4‰. In addition, the additional surface current density generated by mineral bodies can be calculated by the dipole current source model. Therefore, sulfide semiconductor minerals may act as natural thermoelectric conversion media to profoundly affect the transformation and transfer of energy inside the Earth.

Abstract:To understand the mechanism of magnetic variation of red earth in southern China, the authors investigated magnetic characteristics, characteristics of magnetic minerals and degree of weathering of Jiujiang red earth by using magnetic susceptibility instrument, scanning electron microscope and X-ray fluorescence spectrograph. The results indicate that the upper sandy clay has experienced weaker weathering than the lower net-like red earth, but it has a higher magnetic field strength than the lower net-like red earth. The increase in magnetic strength is closely related to the content of superparamagnetic particles and multidomain magnetite. Increasing weathering results in the destruction of the magnetite crystals and the transformation of ferromagnetic minerals to weakly magnetic minerals, which is the main reason causing a lower magnetic strength of net-like red earth than magnetic strength of the sandy clay. The results also indicate that multidomain magnetite in red earth is not formed in weathering and pedogenesis but in the weathering residue from the parent material of the red earth. From middle Pleistocene to late Pleistocene, the climate changed from hot and humid to cold and dry and weathering intensity gradually decreased, resulting in more ferromagnetic minerals in the upper sandy clay than in the lower net-like red earth. Therefore, the main magnetic-bearing minerals in red earth are not the products formed in weathering and pedogenesis, and magnetic characteristics of red earth can't reveal the climate change.

Abstract:To explore the toxic effects of chrysotile asbestos and ceramic fibers on pulmonary inflammation and oxidative stress in Wistar rats, the authors randomly divided early weaning clean level of Wistar rats into 3 groups, namely, chrysotile asbestos exposure group, ceramic fibers exposure group and negative control group. The Wistar rats were administered by intratracheal instillation of chrysotile asbestos and ceramic fibers at the concentration of 2.0 mg/mL once a month. And 6 rats were sacrificed at 1, 6, and 12 months to observe pathological changes of lung tissues, bronchoalveolar lavage fluid (BALF) and lung tissues related indicators. The results showed that there were different degrees of pathological changes in the exposed groups, and the total number of white blood cells in BALF of exposed groups was higher than that in the negative control group at each time point (p<0.05). The percentage of white blood cells, neutrophils and lymphocytes in the exposed group increased with the prolonged exposure time (p<0.05), and the percentage of macrophages decreased (p<0.05). The content of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and nueclear factor-κB (NF-κB) in lung tissues of the exposed groups was higher than that in the negative control group at each time point and increased with the prolonged exposure time (p<0.05), and the content in the chrysotile asbestos exposure group was higher than that of the ceramic fiber exposure group (p<0.05). The concentrations of reactive oxygen species (ROS), malondialdehyde (MDA) in lung tissues of the exposed groups were higher than those in the negative control group at each time point and increased with the prolonged exposure time (p<0.05), and those in the chrysotile asbestos exposure group were higher than the ceramic fiber exposure group (p<0.05). The superoxide dismutase (SOD) activity of the exposed groups decreased with the prolonged exposure time (p<0.05); there was no difference between exposed groups and the negative control group at 1 month (p>0.05); those in the chrysotile asbestos exposure group were lower than those in the ceramic fibers exposure group and lower than those in the negative control group at 6 and 12 months (p<0.05). All these results prove that chrysotile asbestos and ceramic fibers could cause toxic effects of inflammation and oxidative stress in lung tissues of rat, and chrysotile asbestos induced toxicity was stronger than ceramic fibers.

Abstract:Chrysotile asbestos from four major mining areas in China was selected to prepare inhalable dust with particle size less than 10 μm. Male Wistar rats were exposed by non-exposure tracheal instillation and weighed and sacrificed at the time in 1, 3 and 6 months. The lung tissues were quickly separated, the lung morphology was observed and weighed, and the lung organ coefficient was calculated. The pathological changes of lung tissue were observed by light microscopy with HE staining, and the expression of p53 and p16 genes were determined by RT-PCR to investigate the biosafety of chrysotile fiber in China. The results show that the size of chrysotile fiber in the main mining areas was less than 10 μm, which could meet the standards of inhalable dust. The structure and active groups of the dust before and after grinding were not damaged. The body weight of the Wistar rats was significantly reduced, the lung weight was significantly increased, and the lung organ coefficient was increased. The lung tissues of Wistar rats in the exposed group showed severe pathological changes, and there were different degrees of congestion, edema, inflammatory cell infiltration and fibrosis. The expression of p53 and p16 genes in the lungs of Wistar rats exposed to 1~6 months was significantly decreased. Based on the above results, it was found that the inhalable fiber dust of chrysotile asbestos in four major mining areas in China damaged the lung tissue of Wistar rats in different degrees and ways. With the prolonged exposure time, the expression of p53 and p16 in the lung of Wistar rats was significantly decreased. It is inferred that the inhalable fiber dust of chrysotile asbestos in four major mining areas in China has the risk of lung cancer.

Abstract:To explore whether vitamin B complex (folic acid, B6 and B12) can inhibit the acute lung injury of PM_2.5 in rats, the authors randomly divided 56 SD rats into control group, different doses (0.4, 2.0, 10.0 mg/mL) of PM_2.5 exposure groups and corresponding vitamin B complex intervention groups (0.02 mg/mL folic acid, 1 mg/mL vitamin B₆, 0.002 5 mg/mL vitamin B₁₂). The lung tissue of rats was taken for HE staining to observe histopathological changes and calculate pathological scores. The bronchoalveolar lavage fluid (BALF) was collected to determine the content of total protein (TP), lactate dehydrogenase (LDH), alkaline phosphatase (AKP), acid phosphatase (ACP), malondialdehyde (MDA), superoxide dismutase (SOD) and Catalase (CAT). The results showed that PM_2.5 exposure could cause different degrees of pathological damages of lung tissue in rats, and vitamin B complex could alleviate those damages. Compared with the control group, the content of LDH, AKP, ACP, TP and MDA in BALF of low, medium and high dose of PM_2.5 groups significantly increased (P<0.05), while the activity of SOD and CAT significantly decreased (P<0.05). The content of TP and MDA increased with the increase of PM_2.5 doses (P<0.05). The content of LDH, TP and MDA significantly decreased in the intervention groups of three PM_2.5 doses (P<0.05), while SOD and CAT activity significantly increased (P<0.05). The content of ACP was significantly reduced in BALF in low and high dose of PM_2.5+vitamin B complex groups (P<0.05). There was no significant change in ACP content in BALF in the medium dose of PM_2.5+vitamin B complex group. Only the low dose of PM_2.5+vitamin B complex group exhibited a decrease in AKP content (P<0.05), and the other intervention groups showed no significant change in AKP content. Therefore, it is held that PM_2.5 could break the pulmonary oxidation-antioxidant balance to cause acute lung injury in rats, while vitamin B complex could alleviate the damage to protect the body.

Abstract:In this study, the authors chose 123 breast pathological mineralization samples and made a micro-morphology classification study using optical microscope as well as scanning electron microscope. Then, the relationships between the type of breast mineralization and the age of the patient as well as the type of breast lesion and the stage of cancer were discussed by using statistical methods. Based on the resolvable morphology under the optical microscope, the authors divided the mammary mineralization into two types:granular aggregates and massive aggregates; granular aggregates are regular granular calcifications less than 200 μm, with a few having rings. The band structure is tightly bound to the organic structure; the block aggregate is assembled by flaky calcification with the size more than 200 μm, and the aggregates' shape is irregular. Statistical analysis shows that, with the increase of age, the pathological proportion of the aggregates increases, while the pathological proportion of the granular aggregates decreases, and the sensitive age partition is 50 years old; the granular aggregates appear separately in patients over 50 years old and under 50 years old. The probabilities are 24% and 53%, respectively; the mass aggregates are predominant in patients with breast carcinoma in situ (71.4%), and the granulating aggregates are predominant in patients with breast fibroadenomas (64.5%). This study can provide a new auxiliary method for the diagnosis of breast cancer based on the refined mineralogical feature of breast mineralization.

Abstract:The crystal chemical behavior of zinc in bioapatite is different from that in geological body, thus the traditional theory of apatite isomorphism substitution is not completely applicable to the Ca site substitution in bioapatite. In order to explain the appearance of zinc in bioapatite, the authors made a review on the existence of zinc and the mechanism of zinc substitution for Ca site and the influence of zinc substitution in this paper. The implications of crystal chemistry of zinc in bioapatite on the diagnosis and treatment of human tumors were also discussed. Both theoretical and experimental results show that zinc incorporation into bioapatite can take place by occupying the Ca2 vacancy of the defect complex and the local structure would shrink as a whole. The substitution of zinc would have a great impact on crystallite dimension, crystallinity, cell parameters and so on. When zinc is fixed in the lattice of pathological calcification associated with human tumors, it might affect the zinc content in surrounding tissues and body fluids, thus affecting the metabolism of zinc in human body.

Abstract:Based on cathodoluminescence (CL) images, the authors present LA-ICP-MS and SHRIMP U-Pb zircon data of biotite-quartz schist and granitic leucosomes in the Shigu-Liming area. Most zircon grains separated from biotite-quartz schist show clear oscillatory zoning, and most of them from granitic leucosomes are characterized by core-rim structure with strongly or weakly oscillatory zoned cores and narrow black rims. Analysis of zircon cores from biotite-quartz schist and granitic leucosomes yielded U-Pb ages of 2 637~743 Ma with age peak at 858~852 Ma, indicating that their sediments were mainly transported from Neoproterozoic magmatic rocks of western Yangtze Block and also from Archean to Paleoproterozoic basement rocks and deposited after~852 Ma. These zircon rims have low Th/U ratios (<0.1) indicating the timing of anatexis. U-Pb analysis spots yielded ages of 225~197 Ma, and this age population is completely consistent with the age range of the Permian-Triassic metamorphic events of Jinshajiang-Diancangshan-Ailaoshan complex.

Abstract:Volatiles such as H₂O, CO₂, F, Cl and S are important components of the mantle. They play vital roles in the seismic characteristics and conductivity of the mantle, mantle inhomogeneity, mantle rheology, mantle melting and melt evolution despite their low content in the mantle. Research on volatiles of melt inclusions in minerals and glass has become a hotspot. Furthermore, the melt inclusion is the best medium to study the composition of the mantle and magma volatiles by virtue of their unique advantages. The melt inclusion directly captures the components in the magma during the formation of the mineral. Due to the presence of the host mineral, the melt inclusions can maintain independent evolution without being affected by the external environment, so that the volatile information on the magma can be well preserved. At the same time, investigating the volatiles of melt inclusions is the direct way to obtain the volatile content of magma prior to the magma eruption, so lots of studies of melt inclusions have been conducted to restore the volatile content before magma eruption. If the modern analytical methods, such as scanning electron microscopy, electron microprobes and ion probes, are used to perform detailed petrographic observations on melt inclusions combined with experimental studies to determine the changes after the capture of the melt inclusions, the melt inclusions would play an important role in the study of the volatile content of the magma system and source processes. Thus, this paper systematically introduces several important problems on studying the volatiles in melt inclusions, including the analytical methods, solubility of volatiles in magma, the reliability of volatiles data and the application of volatiles.