生物土壤结皮对库布齐沙漠北缘土壤粒度特征的影响

对库布齐沙漠北缘不同发育阶段的生物土壤结皮及其下层土壤粒度特征进行分析。结果表明：流动沙地和藻类结皮表层均以细砂和中砂成分为主,藓类结皮表层以细砂和极细砂为主。生物土壤结皮表层的中粉砂至黏土、粗粉砂和极细砂含量均高于其下层土壤。两种结皮样地均属于分选性较差等级,但结皮下层土壤分选性中等,3类曲线均不对称,属于正偏-极正偏等级,藓类结皮和藻类结皮表层的峰形均属于中等尖锐水平,而流动沙地的曲线尖窄。生物土壤结皮的成土作用随着结皮的发育阶段和土层深度的增加而表现出差异性和复杂性。     

Relationship between geoacoustic properties and chemical content of submarine polymetallic crusts from offshore Brazil

Abstract

Marine mining is the ocean’s new exploration frontier, and polymetallic crusts (PMCs) and ferromanganese nodules are considered a strategic resource for the future. Acoustic geophysical methods are a valuable tool for oceanic research and have been employed for several decades in the exploration of marine resources and environmental evaluations. The main objective of this work was to investigate the correlation between the chemical composition of PMCs from three different areas along the Brazilian continental margin and their physico-acoustic attributes (P-wave velocity, density and acoustic impedance). The results show that the geoacoustic properties of PMCs are correlated to their chemical composition. Measurements showed positive and negative trends between acoustic impedance and studied elements (Fe, Mn, Co, Cu, Zn, W and Ni) according to the direction of measurement, indicting high anisotropy levels. Our study sheds initial light on the correlation between acoustic properties and metal content of PMCs. The study facilitates assessments of the acoustic responses of PMCs allowing more efficient prospection and exploitation compared to ship-board geophysical techniques that are too qualitative to identify PMCs. The results can contribute to determining the best procedures and techniques for more efficient future exploration of this resource.     

现代海底热液柱中锰元素的分析及其地球化学

研究锰在热液中的地球化学性质对于更好地了解热液在海洋中的循环过程和扩散情况很有意义,虽然影响热液中锰的地球化学性质的因素很多,但锰确实是示踪热液活动的最敏感、最有效的元素之一。主要总结了现代海底热液柱中锰元素的分析方法进展,同时对热液柱中锰元素的地球化学特征进行了研究。     

从低品位碳酸锰矿石中富集回收锰的绿色化学工艺研究

阐述了采用铵盐法从低品位碳酸锰矿石中富集回收锰的方法,该方法是将低品位碳酸锰矿石与NH4Cl通过研磨混合均匀,在管式炉中于450℃焙烧1h,焙砂采用热水浸取,得到氯化锰浸出溶液。用焙烧过程产生的氨气及二氧化碳气体通过真空通入浸出液,将锰沉淀下来,过滤、干燥后得到锰精矿;滤液蒸发浓缩、结晶,得到了NH4Cl固体,可以复用。结果表明,采用该工艺的锰回收率达90％以上。认为该方法是一种从低品位碳酸锰矿石中富集回收锰的绿色化学工艺。     

Aqueous Oxidation of Sulfur(IV) Catalyzed by Manganese(II): A Generalized Simple Kinetic Model

The reaction kinetics of S(IV) autoxidation catalyzed by Mn(II) in the pH range 3–5 typical for atmospheric liquid water, was investigated. For reactions with pH maintained constant during the reaction course, the predictions obtained by a simple integral approach cover kinetic results only for concentrations of HSO ₃ ⁻ up to 0.2 mM at pH 4.5. Thus, a generalized simple kinetic model, which can be used for predicting the reaction kinetics in wider concentration, pH and temperature ranges, was derived. This model is based on the assumption that the reaction rate is proportional to the concentration of a transient manganese-sulfito complex formed in the initial step of a radical chain mechanism. In the proposed power law rate equation

锰银氧化矿选冶工艺的研究现状及进展

锰银氧化矿在中国是一种重要的矿床类型 ,但在目前经济技术条件下仍属于难选冶和无商业价值的矿石类型。文章对国内外锰银氧化矿选冶技术的研究现状和进展进行了比较全面的评述     

Superficial alteration and soluble salts in the calcarenite weathering. case study of almohade monuments in Rabat: Morocco

This work analyzes the stone superficial deterioration of some monuments in Rabat city. The rock is a calcarenite with porous texture, rich in calcium carbonates and fossils. The techniques used to study the surfaces altered by blackening or black crusts, are the SEM equipped with EDX microprobe, the X-ray diffraction, and the analysis of the soluble salts by ionic chromatography for anions and flame spectrometer for cations. They reveal significant contents of calcium sulphates, mainly gypsum, often associated with sodium chlorides. These salts known to have a destructive effect on the calcareous stones seem to be originated from the contamination by atmospheric pollutants, particularly sulfur dioxide, and by the marine sprays.     

控制北太平洋深水中 Pb、Nd 同位素演化的不同因素

近年研究表明，大洋中溶解的 Pb和 Nd 以陆源来源占主导。但对 Pb和Nd 进入大洋的途径存在很大争议。笔者研究了3块中北太平洋铁锰结壳（CJ01，CLD01，CB12）的元素含量和 Pb、Nd 同位素组成。根据 Co 含量经验公式法定年，结合几块结壳的剖面 Pb 同位素演化曲线与 Os 同位素演化曲线，确定所研究的中北太平洋铁锰结壳的底部年龄约为 75Ma。3块结壳不论磷酸盐化与否，其 Pi、Nd 同位素随时间的演变曲线均十分相似，且 Pb 同位素演化趋势与北太平洋岩心（LL44－GPC3）中的风沙的 Pb 同位素演化趋势相似。这些结壳的 Nd 同位素演化趋势也相似，但与岩心 LL44－GPC3 中风沙的 Nd 同位素的演化曲线完全不同。由此得到以下结论:(1)通过研究2块结壳，首次提出太平洋铁锰结壳的年龄超过70Ma，得到了白垩纪末及整个新生代中北太平洋深水 Pb、Nd 同位素的演化。并且揭示磷酸盐化不会明显改变结壳中的 Pb、Nd 同位素组成。（2）风沙是中太平洋深水溶解 Pb 的主要来源。太平洋中的 Pb 由来自大陆风沙富放射成因 Pb 和来自火山弧非放射性成因 Pb 之混合，二者的量随时间变化。60Ma 之前，北美大陆粉尘是太平洋 Pb 的主要来源，而从40 Ma 开始，亚洲大陆粉尘对 Pb 总量的贡献日益重要。在约55 Ma 期间是大陆粉尘对海水 Pb 贡献最小的时期，与温暖气候相吻合。（3）风成粉尘对中北太平洋深水中的 Nd 的贡献可以忽略。新生代太平洋边缘火山岩风化侵蚀作用加强，是中北太平洋ENd值升高的主要原因。     

甘肃省成县金家坪锰矿地质特征及找矿前景

通过对该区区域地质背景及金家坪锰矿地质特征的分析,认为该锰矿石形成可分为陆相期、海相期、成矿物质固化失水结晶期及成矿后裂隙充填期4个阶段。矿床成因属海相沉积—次生再造型锰矿。     

Analysis of F, Al, Mn, Zn, Fe, Cu, Ca and Mg concentrations in brick teas from main producing areas in China

Brick-tea-type fluorosis is a peculiar endemic disease in China, which had been discovered in minority areas of western China since 1980, and distributed mainly in Tibet, Inner Mongolia, Gansu, Xinjiang, Qinghai and parts of Sichuan Province. The prevalence rate of fluorosis in Tibetan and Mongolian nationality people was higher. Epidemiological investigation showed that fluorosis morbidity and degrees were different in different brick-tea drinking areas, and it was probably caused by drinking various kinds of brick tea from different regions. Therefore, we collected 33 samples of brick tea from six provinces where minority nationalities were accustomed to drinking a large quantity of brick tea. F concentrations were determined by the combustion hydrolysis-ion selective electrode method. The results showed that among the brick teas, the F concentrations ranged from the minimum 74.1 mg/kg in Yunnan Province to the maximum 991.2 mg/kg in Sichuan Province. Besides, there was a great difference among the various kinds of brick tea, and F concentrations decreased in the order of Kang brick tea, Green brick tea, Black brick tea, Mi brick tea, Fu brick tea, Chitsu ping tea, Puerh tea, and Tuo tea. The average F concentration in brick teas was 431.92 mg/kg.