Isotopic Compositions of Sulfur in the Jinshachang Lead–Zinc Deposit, Yunnan, China, and its Implication on the Formation of Sulfur-Bearing Minerals

The Jinshachang lead–zinc deposit is mainly hosted in the Upper Neoproterozoic carbonate rocks of the Dengying Group and located in the Sichuan–Yunnan–Guizhou(SYG) Pb–Zn–Ag multimetal mineralization area in China.Sulfides minerals including sphalerite,galena and pyrite postdate or coprecipitate with gangue mainly consisting of fluorite,quartz,and barite,making this deposit distinct from most lead–zinc deposits in the SYG.This deposit is controlled by tectonic structures,and most mineralization is located along or near faults zones.Emeishan basalts near the ore district might have contributed to the formation of orebodies.The δ34S values of sphalerite,galena,pyrite and barite were estimated to be 3.6‰–13.4‰,3.7‰–9.0‰,6.4‰ to 29.2‰ and 32.1‰–34.7‰,respectively.In view of the similar δ34S values of barite and sulfates being from the Cambrian strata,the sulfur of barite was likely derived from the Cambrian strata.The homogenization temperatures(T ≈ 134–383°C) of fluid inclusions were not suitable for reducing bacteria,therefore,the bacterial sulfate reduction could not have been an efficient path to generate reduced sulfur in this district.Although thermochemical sulfate reduction process had contributed to the production of reduced sulfur,it was not the main mechanism.Considering other aspects,it can be suggested that sulfur of sulfides should have been derived from magmatic activities.The δ34S values of sphalerite were found to be higher than those of coexisting galena.The equilibrium temperatures calculated by using the sulfur isotopic composition of mineral pairs matched well with the homogenization temperature of fluid inclusions,suggesting that the sulfur isotopic composition in ore-forming fluids had reached a partial equilibrium.     

阿富汗艾娜克铜矿西矿区构造成矿特点

通过对阿富汗艾娜克铜矿矿区地质条件的研究,分析了矿区的构造特征。剖析了艾娜克复式背斜及其北翼1—3号次级背、向斜构造特征和4组断裂构造特征。探讨了矿区的主要构造活动(褶皱和断裂)对艾娜克铜矿控矿的影响。     

Heavy metal contamination of an arid river environment: Gruben River, Namibia

The dispersal of metalliferous pollution from several spoil heaps produced during 20th century copper mining in the Gruben River valley, Namibia is examined. The Gruben River flows through an extremely arid environment with an average rainfall of ˜25 mm p.a. The potential for physical and chemical remobilisation of Cu, Zn and Ni is assessed by examining the spatial and temporal distribution of metal-contaminated sediment deposited within the confines of the channel. The relationships between metal content, grain size, geomorphic environment and the downstream distribution of metals are discussed. The phase-specific heavy metal concentrations of sediments, collected as part of the downstream sampling programme, are also examined using progressively more aggressive sequential acid extractions. In addition, metal concentrations are compared with Dutch guidelines for soil contamination to ascertain the extent of environmental risk.Total metal concentrations show that the Gruben valley is highly contaminated, particularly with respect to Cu and Ni concentrations, which exceed Dutch target values for Cu (36 ppm) in 94.7% and Ni (35 ppm) in 90.5% of samples, respectively. Zn concentrations are much lower with only 6.3% of the samples exceeding the target value (140 ppm). As might be expected, the metal–sediment concentrations of Cu are the most highly elevated, with a peak value of 10,500 ppm being recorded from material collected from suspended sediment transported during a minor flow event that occurred in March 1999. Lower energy and fine-grained sedimentary environments are shown to be clearly associated with higher metal concentrations. Sequential extractions of metals show that of the three principal elements considered in this study, only a negligible proportion of Cu (0.41%) is held in the exchangeable phase. Ni and Zn were below detection limits. Although the total metal concentrations in the Gruben River valley sediments are extremely high and are in themselves a concern, the small percentage of metals held in the exchangeable phase and the low potential for remobilisation under the arid conditions would suggest that they pose only a minor risk to the environment.     

In situ heavy metals (copper, lead and cadmium) in different plankton compartments and suspended particulate matter in two coupled Mediterranean coastal ecosystems (Toulon Bay, France)

We monitored the concentrations of copper, lead and cadmium in seawater, in suspended particulate matter (SPM) and in bacteria, phyto- and zooplankton communities separated from abiogenic particles, over a one year cycle in two coupled Mediterranean coastal ecosystems (Little Bay (LiB) and Large Bay (LaB)). Metals were present in seawater in the order Cu > Pb > Cd in both bays and showed important variations within the same month than among months. In LiB, their concentrations were between 0.62 and 2.82 μg Cu l⁻¹, 0.16 and 19 μg Pb l⁻¹ and 0.007 and 0.14 μg Cd l⁻¹, respectively, whereas in LaB, they were between 0.23 and 2.11 μg Cu l⁻¹, 0.09 and 0.76 μg Pb l⁻¹ and not detected and 0.65 μg Cd l⁻¹. SPM play an important role on metal adsorption, especially for copper. Bioaccumulation factors showed that bacteria and phytoplankton accumulate metals whereas zooplankton tends to biodiminish them in the plankton food web.     

A Study of the Thermodynamics and Kinetics of Copper Adsorption Using Chemically Modified Rice Husk

The use of rice husk as a low cost adsorbent for the removal of copper from wastewater has been explored in a laboratory scale experiment. The rice husk used for the study was treated with alkali to increase the sorption properties. The influence of metal ion concentration, weight of biosorbent, stirring rates, temperature and pH were also evaluated, and the results are fitted using adsorption isotherm models. From the experimental results it was observed that almost 90–98% of the copper could be removed using treated rice husk. The Langmuir adsorption isotherm, Freundlich isotherm and Tempkin isotherm models were used to describe the distribution of copper between the liquid and solid phases in batch studies, and it was observed that the Langmuir isotherm better represented the adsorption phenomenon. The experimental rate constant, activation energy, Gibbs free energy, enthalpy and entropy of the reaction were calculated in order to determine the mechanism of the sorption process.     

硫酸（亚硫酸）盐渍土单次盐胀和冻胀发育规律研究

对盐胀和冻胀规律的研究有助于深入认识硫酸（亚硫酸）盐渍土的工程性质。通过对天山北麓水磨河流域细土平原区硫酸（亚硫酸）盐渍土盐胀和冻胀试验研究发现：（1）随着温度的降低,试样盐胀和冻胀率逐渐增大。试样冻结前土体产生的膨胀是盐胀,试样冻结后产生的膨胀是盐胀和冻胀,当土体达到-15℃以后,土体盐胀和冻胀趋于稳定。（2）硫酸钠含量不变的情况下,随着含水量的增大,其起胀温度降低。土体起胀温度取决于土体中硫酸钠析水结晶温度、硫酸钠结晶含量的多少、土体结构、内摩阻力、粘聚力、土颗粒间的引力、土体孔隙间和孔隙接触间吸收结晶硫酸钠的程度。（3）硫酸钠含量增加,其单次盐胀和冻胀率变化区间增大。     

硫酸铁钾转化法制取硫酸钾

以钛白副产绿矾和氯化钾为原料 ,采取硫酸铁钾转化法制备硫酸钾。该工艺既具有反应时间短、操作控制方便、产品质量符合国标要求等优点 ,又治理了钛白粉厂环境污染 ;既具有一定的经济效益 ,又有一定的社会效益。     

闹牛山铜矿床火山机构控矿特征及次火山岩系列演化

闹牛山铜矿床受火山机构控制,反映了成矿作用从供矿→运矿→集中→定位的全过程,次火山岩从基中性→中性→酸性方向演化,铜矿与次火山岩具有同空间,同时间（或稍后）,同源的特征。     

钛白废液的治理与综合利用硫酸钾溶解平衡的热力学研究

本文应用热力学基本原理和方法研究硫酸钾溶解平衡,结果表明,硫酸钾在纯水中的溶解度随温度变化符合前人总结的实验规律,而在４３℃的钛白废水液液中硫酸钾有反常深 现象,这为确定硫酸钾结晶析出的最佳温度提供了热力学依据,通过热力学计算,论证了硫酸钾溶解平衡符合势学基本原理。     

氯化钾与硫酸钠制硫酸钾工艺的优化

根据 K+ ,Na+∥ Cl-,SO4 2 -— H2 O体系相图 ,提出了氯化钾与芒硝制备硫酸钾工艺中新的工业化生产循环和解决钾芒硝富集问题的具体方案 ,取得良好效果。