Abstract:Three typical manganese coatings, i.e., rock varnish, dendrite and soil iron-manganese cutan, were collected and corresponding thin sections were made for laboratory research. The authors utilized optical microscope, micro-Raman spectrometer, scanning electron microscope and energy dispersive X-ray detector to systematically study the micro morphological features, mineral assemblage and elements distribution of these three manganese coatings. The results suggest that rock varnish is dark layered or botryoid deposit which consists of birnessite, hematite, goethite, clay minerals, etc., indicating a highly-mixed coating. The boundary between rock varnish and substrate, and also the microlaminations which arise from the manganese content fluctuation within the sample profile, are obvious on closer inspection. Dendrite is black branch-like coating and mainly composed of hollandite-group minerals. Unlike rock varnish, dendrite, enriched in manganese and devoid of silicon and aluminum, shows pilotaxitic texture with its substrate. Soil iron-manganese cutan, a kind of black soft deposit, comprises birnessite, hematite, goethite, ilmenite, clay minerals, etc., and can be further divided into an outer black manganese-rich belt and inner yellowish-brown iron-rich belt. The micro morphological features of these manganese coatings, together with elements distribution, reveal intimate relationship with their formation mechanism.

Abstract:With rough tin concentrate of Datun dressing plant as the study object, the authors used chemical analysis, X-ray diffraction analysis and optical microscopy analysis to investigate chemical composition, mineral composition and mineral assemblage of rough tin concentrate. The results indicate that the grade of tin in rough concentrate is 13.80%, and tin mainly exists in the form of cassiterite. The TFe possesses 30.78% in rough tin concentrate, and mainly exists in the forms of limonite and pyrrhotite, whereas the pyrrhotite is the main factor for the high sulfur content of the rough tin concentrate. The main gangue minerals are dolomite, tremolite, tourmaline, quartz, muscovite, fluorite etc., and gangue minerals and cassiterite have complex association relationship and encapsulation relationship. According to the results of process mineralogy, the rough tin concentrate of Datun dressing plant is suitable for pre-desulfurization by flotation, which is designed to desorb the sulfide, and the gravity separation process of flotation tailings should be adopted to improve tin grade and recovery. The results of the study provide scientific basis for process modification and rational exploitation of tin resources in Datun dressing plant.

Abstract:The Dexing copper deposit is one of the famous porphyry copper deposits characterized by low grade and multi-elements in China. In the past years, only the Cu element was recovered, and the other elements, such as Re, Co, Au and Ag, were hardly considered in the heap leaching process. In this study, XRD, SEM and EDS, EMPA, ICP-MS analysis and phase analysis were conducted to study mineral composition variations, modes of occurrence and spatial distribution regularity of associate elements in order to put forward the feasible evaluation on comprehensive utilization in this paper. The main conclusions are as follows:Au mainly occurs as native gold; Ag occurs as both simple substance and compounds; Co mainly occurs as isomorphs; Mo and Re elements have no economic value in the heap leaching field due to their very low content. However, recovery of Co element in the acid water reservoir can possess important economic value with its higher content of 19 g/t and its higher leaching rates of 73%. Au and Ag are just potential resources with the much lower leaching rates and the lower average content of 0.1 g/t and 0.39 g/t, respectively. Besides, the further study should be performed with regard to recycling rutile due to its rich content and its average particle size of 20 μm.

Abstract:In this study, TiO₂ was loaded onto natural nano mineral chrysotile/leached silica by using hydrolysis of tetrabutyl titanate at room temperature using sol-gel method. The morphological properties and microstructure of the supporters and catalysts at different calcination temperatures were characterized by N₂ adsorption/desorption, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photocatalytic reactivities of these different catalysts were investigated by UV-assisted degradation of 10 mg/L Rhodamine B. The results show that the TiO₂-loaded silica calcined at 750℃ exhibits significantly excellent reactivity with the removal rate of Rhodamine B up to about 91.57% after irradiation for 40 min, the good adsorption capabilities of the supporters can also contribute to the removal rate of Rhodamine B.

Abstract:All sphalerites from 19 ore deposits were crystallized in cubic phases with various chemical compositions. The substitution of Fe element for Zn ranges from 0.235% to 14.826%, while the substitution of Cd element for Zn ranges from 0.133% to 1.576%. With the change of the Fe element from low to high, the color of natural sphalerite becomes darker and eventually becomes black, and the band gap, which was narrow than pure ZnS, was reduced from 3.18 eV to 2.28 eV, with all response in visible light excitation. The photocatalytic performance indicates that the sample with both lower Fe content and higher Cd content shows the highest activity to degrade Methyl orange (MO). For example, the degradation of MO (30 mg/L) with efficiency reached 82.11% under visible light irradiation for 4 h by natural sphalerite with Fe 4.262% and Cd 1.576% (1 g/L). The Fe content in sphalerite contributed to the band gap value and the range of light spectrum responses, while Cd content affected photocatalytic properties. The results obtained by the authors provide the scientific basis for the profitable utilization of base metal resources like natural sphalerite.

Abstract:In this study, nanosphere and nanorod hematite were synthesized through electrode position, and both were confirmed as the pure and sole phase of hematite by XRD and Raman. Morphological observations by SEM of electrodes showed that the diameter of nanosphere hematite particles was 20±5 nm, and nanorod hematite particles synthesized in eletrolyte containing ethylene glycol had the length of 90±10 nm and the diameter of about 20 nm. They both exhibited significant absorption in the range of 300~550 nm in the UV-Vis spectroscopy, and the calculated bandgap width for nanosphere and nanorod hematite was 2.00 eV and 1.99 eV, respectively. The calculated carrier density for nanospheres was 3.16×10²⁰ cm^-3 and that for nanorods was 1.95×10²¹ cm^-3, fitted through Mott-Schottky curves measured in 1 M KOH solution. The results of photoelectrochemical experiments indicated that the current density of nanorods was lifted up to 5.5 times with illumination compared with that under dark condition under the potential of 0.6V (vs. Ag/AgCl). Nevertheless, the fact that the current density of nanospheres rose by just about 77% indicated that, although both nanosphere and nanorod hematite exhibited photoelectric response, the nanorods performed a more remarkable capacity in photoelectrocatalysis.

Abstract:As the problem of environmental pollution has become increasingly aggr avated,the conversion of solar energy catalyzed by semiconductor material has c aused much concern in the field of catalytic and environmental protection.Nano-hematite electrodes with different deposition time were synthesized by electroch emical method more quickly and effectively in this paper.X-ray Diffraction (XRD) and Raman spectroscopy confirmed that the electrode had single phase of hemati te.Morphology information was obtained by Atomic Force Microscope (AFM).The na no-hematite had a particle size of 52.1(±1.48) nm×50.5(±1.49) nm,and the su rface height was concentrated in the range of 70~100 nm,which was consistent with the normal distribution law.Moreover,the UV-Vis Diffuse Reflectance spectr a illustrated the significant absorption of visible light from 350 nm to 600 nm, and the calculating result of band gap was about 2.0~2.1 eV.In photoelectro ch emical experiments,the photocurrent density-time curve and I-V curves indicated that the electrode had great photoelectrocatalysis activity and the reaction pr ocess accorded with the Langmuir-Hinshelwood kinetics model.Furthermore, 10-minute-deposited hematite electrode was used to investigate the activity of photoelectrocatalytic degradation of phenol.The results showed that degradation rate o f phenol reached 62% after 6 h under a constant potential of 0.65 V versus SCE (Saturated Calomel Electrode) and the constant of reaction rate k was 0.16 h^-1 (R₂=0.996) when the first-order kinetics reaction model was fitted. It is thus s hown that the electrochemically deposited nano-hematite possesses satisfying con ductive properties and the capability of degrading phenol and other organic poll utions.

Abstract:Lead is widely distributed in nature, and its soluble salts have great toxicity to animals, plants and human bodies. The removal of lead pollution in the environment by biological remediation such as fungi has becomes one of the hot topics. In this paper, the anatase electrode was synthesized using sol-gel method, and characterized by X ray diffraction (XRD), the Raman, environmental scanning electron microscopy (ESEM) and electrochemical testing. The light-semiconductor mineral-microbial system was successfully constructed with anatase electrode and Aspergillus niger Bpb1. The effect of photoelectron on adsorption of lead ions by Aspergillus niger was studied. The experimental results showed that the adsorption rate of the experimental group increased by 33.6% on average with the highest being 42% compared with the control group. The photoelectron did not affect the morphology of lead minerals. Combined with energy spectrum test and previous literature, the authors found that lead ions were combined with organic acids to form minerals with organic lead salts, which were twined in hyphae. In this study, the anatase photoelectron could enhance the adsorption rate of lead ion by fungi, but did not affect its morphology.

Abstract:In this study, biochar supported nanosized zero valent iron composite (NZVI/BC) was assembled from biochar and nanoscale zerovalent iron (NZVI), while NZVI was prepared by liquid phase reduction method. The XRD patterns showed that NZVI/BC was composed of biochar and NZVI. SEM indicated that NZVI particles agglomerated greatly, and dispersed well after being distributed on biochar grains. The focus was placed on the effects of the solution pH, dosage and ratio of Fe/C for the composite as well as the initial concentration of NO₃^- on the reduction of nitrate by NZVI/BC. The research clearly demonstrates that NZVI/BC exhibits highly efficient reductive capability. The reductive removal rate of NO₃^- reached approximately 75% within 2 h by using NZVI, and reached approximately 96% by NZVI/BC under the same certain condition. Therefore, NZVI/BC is a promising scavenging material for nitrate.

Abstract:Electrochemical technology offers an alternative solution to many environmental problems because electrons provide a versatile, efficient, cost-effective, and clean reagent. The technology includes electrocatalysis, heterogeneous photocatalysis, photoelectrocatalytic (PEC) process and so on. Birnessite electrodes were synthesized by electrochemical method in this paper. Mineral phase and morphology were studied by X-ray Diffraction (XRD) and scanning electron microscope (SEM). UV-Vis absorption spectra demonstrated that the birnessite had a significant absorption of visible light from 300 to 600 nm and a direct band gap of 2.14 eV. Moreover, the flat band potential was 1.15 V and the carrier concentration was 3.3×10¹⁹ cm^-3 as evaluated by Mott-Schottky. The results demonstrate that birnessite is a great n-type visible light excitation semiconducting material. Meanwhile, a cheaper and more efficient solar cell was used to replace the traditional electrochemical devices such as electrochemical workstation, which realized an enhanced photoelectrocatalytic activity of birnessite. Methyl orange degradation rate was 90.2% at 60 min, which was higher than the sum of degradation rate of birnessitephotocatalysis (2.2%) and electrocatalysis (33.6%). Effective utilization of sunlight was realized and photoelectrocatalytic activity of birnessite was promoted. Moreover, energy was saved and the degradation efficiency was increased. Cyclic degradation showed that decrease degree of the fourth round degradation rate (86.8%) was lower than 5%, compared with the first round (90.3%), and this shows that it has a stability of long term operating. The results obtained by the authors provide a more energy saving, advantageous, and environmentally friendly technique for organic wastewater treatment in the field of environmental mineralogy.

Abstract:Lead pollution is a kind of environmental pollution, which leads to serious problems to ecology and human health. In such a situation, how to repair lead pollution is a key issue that needs to be solved urgently. Compared with other lead pollution remediation methods, bioremediation has unique advantages. Penicillium polonicum, the fungi used in this experiment, is the strain with proven high tolerance and high adsorption rates to lead. On the basis of previous studies, the main purpose of this experiment is to improve the adsorption and immobilization capability of Penicillium polonicum to lead. Double chamber electrolytic cell was used in this experiment to observe the effect of the current on the growth environment and the adsorption of lead by fungi at different voltage ranges from 0.5 V to 1.5 V. The results show that the electric current could either promote or inhibit the adsorption and immobilization of lead ions by Penicillium polonicum. The effect of the current is related to the voltage. The current could enhance the adsorption and immobilization of lead by the strain under the most appropriate voltage range between 1.0 V and 1.25 V.

Abstract:Due to the poor adsorption performance and extreme toxicity of the heavy metal cadmium ion, it is of great practical significance to explore an efficient adsorption material for cadmium immobilization. In this paper, the modification by grafting sulfhydryl silane onto kaolinite was investigated and confirmed by infrared spectroscopy which proved that sulfhydryl groups were successfully introduced onto the surfaces of kaolinite. At the same time, silane modification did not cause the change of kaolinite in the crystal structure. Batch experiments were conducted to investigate the adsorption characteristics of kaolinite and modified kaolinite (K-SH) for Cd²⁺ under different conditions, mainly including pH and adsorption time. The adsorption kinetics of cadmium ions by the two materials is in agreement with the pseudo-second-order kinetic model. Nevertheless, the relevant adsorption isotherm equation showed a good fitness with the Langmuir model. The calculated maximum adsorption capacity of K-SH is 4.375 mg/g, which is 20 times higher than that of original kaolinite. The modified kaolinite grafted with sulfhydryl groups provided a large number of new adsorption sites on its surface, thus significantly improving the capacity of adsorption and immobilization for cadmium ions by coordination and complexation. It is therefore held that sulfydryl organic silicane-grafted kaolinite is a promising soil remediation material.

Abstract:In order to discuss and determine the dissolution kinetics law and influence factors of the dissolution of Ca²⁺ and Mg²⁺ in coral sand, the authors conducted dissolution experiments of Ca²⁺ and Mg²⁺ in aqueous solution under different conditions of the solid-liquid ratio, the rotational speed of the shaker, the particle size of coral sand, the temperature, the pH value, and the salt content of the solution. The results show that Ca²⁺ and Mg²⁺ dissolution in coral sand gradually increased with the reaction time, and the higher the speed, solid-liquid ratio and temperature, the greater the dissolution of Ca²⁺ and Mg²⁺, and the lower pH value is beneficial to the dissolution of Ca²⁺ and Mg²⁺. When particle size of coral sand is 2.36~4.75 mm, and the salt content is 100 mg/L, the dissolution amount of Ca²⁺ and Mg²⁺ reaches the maximum. The statistical analysis shows that the rotational speed, temperature and solution pH have significant influence on the dissolution of coral sand, whereas the pH value among them seems to be the greatest influence factor. Kinetic studies show that the dissolution of coral sand in water is consistent with the internal diffusion model of shrinking nuclei, which suggests that internal diffusion rate is the decisive factor controlling the dissolution reaction. In addition, from 15℃ to 40℃, the dissolution activation energy of Ca²⁺ and Mg²⁺ in coral sand is 78.07 kJ/mol and 74.91 kJ/mol respectively.

Abstract:Advanced oxidation technology based on sulfate radicals is widely used in environmental pollution control with high efficiency and low pollution. In this paper, the system was used to repair soil. Experimental study was carried out in the aspects of the Na₂S₂O₈/Fe²⁺ molar ratio, the pH value of the system and the dosage of Na₂S₂O₈/Fe²⁺. The results show that, when the molar ratio of Na₂S₂O₈/Fe²⁺ is 2:3, the degradation effect of oil pollutants is the best, and the pH value of the system has little effect on the degradation effect. The optimal amount of sodium persulfate and ferrous sulfate solution with 0.1 mol/L concentration is 2 mL and 3 mL in 1 g soil, the degradation effect of No.2 soil is most obvious. Therefore, the amount of contaminated soil per ton is about 2×10⁶ mL, 3×10⁶ mL.

Abstract:Mixed metal oxides constitute a common kind of material in nature, in which Mg-Al mixed oxide (MMO) is widely distributed in the basic-ultrabasic magmatic rocks, evaporates of rivers-lakes and marine sedimentary rocks. In this study, MMO was obtained by calcining of Mg-Al hydrotalcite. Its rehydration features and the related transformation mechanism in silicic alkaline solution under hydrothermal condition were investigated by changing reaction time. X-ray diffraction (XRD) patterns showed that MMO reconstructed to form hydrotalcite firstly, after that hydrotalcite transformed to saponite gradually, along with the formation and disappearance of impure phase (e.g., natrodavyn). ²⁹Si and ²⁷Al MAS NMR results suggested that Al³⁺ cations tended to occupy the tetrahedral sites on tetrahedral sheets. The new findings of this research have great significance for understanding the stability of hydrotalcite, heterogeneous nucleation and growth of hydrotalcite and silicate minerals as well as the formation processes of the hydrothermal saponite deposits.

Abstract:In this study, A549 cells were exposed to PM_2.5 dust-fall of different concentrations. MTT assay was used to evaluate cell viability. Cell morphology was observed through Scanning Electron Microscopy (SEM). Flow cytometry was used to detect the cell cycle induced by PM_2.5. Then the expression levels of p53, p21, CDK1, c-myc and lncRNA H19 were detected by RT-PCR, and cyclin B1 was measured by Western-blot. In addition, the expression of p53, c-myc and CDK1 in A549 cell was detected after transferring H19 siRNA, with the purpose of investigating the mechanism of A549 cell cycle arrest induced by PM_2.5. The results showed that, compared with the control group, A549 cell viability was declined in a dose-dependent manner and time-dependent effect. It was observed that cell morphology was changed and the cell membrane surface adsorbed a large amount of dust particles. The proliferation of A549 cells was inhibited in G2/M phase after being treated by PM_2.5 for 24 h, and the expression of CDK1 and cyclin B1 was decreased by increasing the expression of p53, p21 and H19. In addition, the expression of H19 was successfully inhibited by transferring H19 siRNA, and then the expression of CDK1 was further decreased. It is inferred that exposure to PM_2.5 could inhibit the expression of CDK1 and cyclin B1 by activating p53 and p21 activity, induce G2/M phase arrest, and finally inhibit A549 cell proliferation. In addition, after being exposed to PM_2.5, lncRNA H19 may play a specific oncogenes role in treated cells in that it participated in the cell cycle progression by binding to p53 and c-myc, and hence low expression of H19 caused G2/M phase arrest more obviously.

Abstract:The mutagenicity of inhalable mineral granules (IMG) and interaction with Epidermis staphylococcus, E. coli were studied by Ames test to analyze whether IMG and IMG/body normal flora complex has mutagenicity. The results show that Ames test of the quartz and quartz/E. coli complex on TA98 and TA100 strains assumes positive reaction, Ames test of quartz/epidermis staphylococcus complex on TA98 strains assumes position reaction, whereas Ames test of montmorillonite, calcite, albite and complex from interaction with body normal flora exhibits negative reaction, which suggests that the quartz has direct mutagenic effect, quartz/body normal flora complex still has mutagenicity, but the mechanism of the phenomenon that base replacement mutation effects of quartz disappeared after interaction with Epidermis staphylococcus needs further research.

Abstract:In this study, the human pathologic calcification samples were selected from human heart valve, artery, thyroid, ovarian and breast. Focusing on 38 cases of five different types, the authors carried out a systematic infrared spectrum characterization and, with the help of infrared spectrum method, inferred the presence of the carbonate group and evaluated the carbonate substitution in bioapatite structure. It was found that the basic composition of the five kinds of typical pathologic calcification product was carbonate-hydroxylapatite (CHA). The carbonate content of the samples in the same part remained the same,but the differences of the average content of the carbonate in different parts were obvious. The average content of CO₃^2- in the thyroid as well as the breast was 6.2, 3.3% lower than that in the heart valve. The average content of CO₃^2- in the heart valves was the highest. The infrared spectra showed that the pathological bioapatite mainly was the B-type carbonate substitution (CO₃^2- for PO₄^3-), accompanied by a small amount of A-type carbonate substitution (CO₃^2- for OH^-). The forward contact of the carbonate content inferred by the spectroscopic measurements and the ratio of B/A substitution was unconspicuous.

Abstract:Chrysotile asbestos is a kind of asbestos that is controversial in safety, and it is of great significance to study its pathogenesis in a reasonable and feasible way to reflect its exposure process. A multiple non-exposed intratracheal instillation method was used to expose male Wistar rats under the condition of different concentrations of chrysotile asbestos. After exposure for 1, 3 and 6 months, the rats' body weight and lung coefficient were recorded, and pulmonary tissue and HE Staining slices were observed. The brochoalveolar lavage fluid (BALF) was collected to measure the change of different kinds of white cells, total protein (TP), lactate dehydrogenase (LDH), acid phosphatase (ACP) and alkaline phosphatase (AKP). The results showed that a low mortality was presented by using the multiple intratracheal instillation method. The body weight increased slowly and lung coefficient increased with the time and dosage. The edema, granuloma and atrophy appeared in pulmonary tissue. The increased inflammatory cells, destroyed alveolar and fibrosis were observed by HE staining. Chrysotile asbestos induced the increase of total white cells, the neutrophils and lymphocytes percentages, but the reduction of the macrophages percentage in BALF. The values of TP, LDH, ACP and AKP in exposure groups were higher than those in control group with a significant dose-response correlation. All these results prove that the multiple intratracheal instillation method could be used to simulate the chronic exposure of chrysotile asbestos. The Xinkang chrysotile asbestos could induce lung injury through destroying the lymphocytes, alveolar epithelial cells and alveolar epithelial-capillary barrier.

Abstract:Bitumen, natural copper and quartz generally occur in the interstitial site of mineral grains in dark mass in amygdaloidal basalt from Puge County, southern Sichuan. Natural copper formed after the decomposition of organic matter into bitumen and gases. The authors detected that the content of bitumen and that of natural copper exhibit negative correlation. In the dark clumps, the higher the bitumen and quartz, the lower the copper, but the higher the natural copper and quartz in nearby places, and the interval of crystallization time and space between natural copper and bitumen is very short. The commonly recognized sequence is quartz →bitumen→ native copper. The carbon isotope and infrared spectrum suggest that bitumen is of biogenesis and originated from the carbonate rocks in Permian strata. The results from the homogenization temperature of inclusions in quartz and Raman spectrum indicate that the organic matter in the hydrothermal fluids can be decomposed into bitumen and natural gas (CH₄) under the temperature >350℃; the higher the temperature, the higher the maturity of organic matter, the higher the content of organic carbon in bitumen, the lower the natural copper content in residual bitumen.

Abstract:The trace element geochemical compositions of 3 Early Cretaceous coal seams (20 coal samples, 1 parting sample) from the 0-1 borehole in the Shengli coal field of Inner Mongolia was investigated by using inductively coupled plasma mass spectrometry (ICP-MS). The results show that No. 1 and No.2 coals are lignite (V_daf>44%, transmittance PM<50%) with high ash yield and high sulfur content, the No. 4 coal is long-flame coal (V_daf=42%, PM=53%) with low ash yield and low sulfur content. Compared with average values for coals in the world reported, Sb is enriched; V, Zr, Nb, Hf, and W are slightly enriched in the three coal seams, and the concentrations of other trace elements are either close to or much lower than the world's averages. Relative to things of the upper continental crust, the rare earth elements and yttrium in 20 coal samples are all characterized by heavy REY enrichment, whereas the parting sample is characterized by light REY enrichment.