一水硬铝石矿活化焙烧工艺研究

利用马弗炉对我国一水硬铝石矿进行了活化焙烧的实验研究,以降低拜耳法溶出的温度.研究了焙烧温度、焙烧时间等因素对铝土矿的溶出性能的影响,将活化焙烧矿的溶出性能与原矿的溶出性能进行了对比.利用SEM技术对活化焙烧矿的微观形貌进行表征.实验结果表明:合适的活化焙烧工艺条件为焙烧温度585℃,焙烧时间60 min.在此焙烧条件下,当达到最大溶出率时,焙烧矿的溶出温度较原矿下降了40℃.     

活化焙烧一水硬铝石矿增浓溶出过程动力学

探讨了一水硬铝石型铝土矿在一定条件下活化焙烧后 ,作为后加矿的增浓溶出过程动力学 .得出焙烧矿在增浓溶出过程中受化学反应控制 ,且为一级反应 .推导出了该过程的动力学方程 ,并求得了相应的表观活化能为1 34 .5kJ/mol.对于更深入研究这一新的氧化铝生产工艺流程 ,在原有拜耳法流程基础上 ,通过适当改造 ,达到增产降耗 ,提高我国氧化铝工业在国际市场上的竞争力具有一定的理论意义     

一水硬铝石型铝土矿溶出的动力学模型

针对广西平果－水硬铝石矿溶出过程的特点进行了研究，发现广西平果一水硬铝石型铝土矿的溶出过程不应该用收缩末反应模型来描述，用整体反应核模型对广西一水硬铝石型铝土矿的溶出过程进行了数学模拟，得到了溶出过程的动力学模型，希望这种模型能对铝土矿的溶出过程提供新的理论基础。     

力化学对铝土矿溶出的作用

力化学方法处理铝土矿,可明显改善其溶出性能．对国内２种有代表性的铝土矿：广西平果矿和山西普铝矿采用该法处理,使矿石中的一水硬铝石结构发生变化,从而降低了溶出温度及溶出用碱液浓度,并提高了溶出速率．对力化学引起的反应性能变化及其内在原因进行了探讨．据此确认该法对我国氧化铝工业节能降耗、提高经济效益具有实际意义．     

高硫铝土矿氧化焙烧脱硫的节能条件优化

氧化焙烧法处理高硫铝土矿,具有操作简便、能够同时去除矿石中有机物的优点,但仍存在着能耗高以及一水硬铝石脱水造成氧化铝溶出困难等问题.本研究基于黄铁矿和一水硬铝石的热分析和恒温焙烧实验结果,发现黄铁矿脱硫与一水硬铝石脱水反应起始温度接近,但脱硫反应速率慢而脱水反应速率快,从而提出通过降低焙烧反应温度、延长反应时间来提高脱硫率、抑制脱水率的处理工艺.通过模拟样品和实际样品的焙烧条件优化实验,确定硫含量为3.8%的铝土矿最佳脱硫处理条件为:空气气氛下,焙烧温度460~470℃,焙烧时间15~20min,处理后铝土矿含硫量低于0.5%,符合拜耳法氧化铝生产工艺的要求.     

高硫铝土矿氧化焙烧脱硫研究

针对一水硬铝石高硫型铝土矿,以河南2种地方矿石为原料进行焙烧除硫的研究,并通过对焙烧矿的物相分析进行理论上的探讨。在此基础上,对焙烧矿和原矿的高压溶出进行比较试验,研究溶出液中S2-含量的变化以及焙烧过程对溶出性能的影响。结果表明:硫的物相不同,其硫的脱除率不同;矿石经焙烧后,铝土矿中的黄铁矿FeS2的特征衍射峰消失,而出现了Fe2O3的衍射峰;同时,原矿的一水硬铝石β-AlOOH的衍射峰也消失,而产生了α-Al2O3的衍射峰;原矿经焙烧后溶出液中S2-的质量浓度显著降低,溶出性能更好;对于以黄铁矿为硫的主要物相的河南A矿,在600℃、焙烧60min后,与原矿同时在240℃、焙烧60min进行溶出试验,焙烧矿溶出液中S2-的质量浓度由原矿的1.78g/L下降到0.15g/L,同时,矿石的溶出率由85.27%提高到91.26%。     

粗粒径高硫铝土矿焙烧前后脱硫及溶出性能研究

对贵州省某一水硬铝石型的高硫铝土矿进行焙烧脱硫实验研究。探究焙烧时间、焙烧温度等条件对脱硫的影响,并借助XRD对焙烧机理进行分析;在这个基础上,对比矿物焙烧前后的高压溶出实验,观察两种溶出液中的硫的变化规律以及溶出性能的改变。结果表明:在焙烧温度700℃、时间为30 min及粒径为830μm时,矿石中硫含量从2.33%降至0.68%;矿石经过高温焙烧后,矿石成分发生改变,溶出性能得以提高;对于硫存在形式以黄铁矿为主的高硫铝土矿,焙烧后溶出液的硫浓度相比原矿溶出液大幅降低,且硫的溶出率由原矿的28.8%降至14.8%,氧化铝相对溶出率增加到95%以上。     

用增溶溶出技术处理一水硬铝石矿

以氢氧化铝作为后加矿,采用增溶溶出技术处理一水硬铝石矿·研究了一段溶出配料摩尔分数、增溶温度、后加矿加入量、增溶时间对溶出效果的影响·确定了增溶溶出的工艺条件:一段配料摩尔分数控制在1 55～1 60,增溶温度为210～220℃,增溶时间为15～20min,后加矿加入量为一段溶出时矿石量的10%～15%·此条件下铝土矿的溶出率达到88 8%以上,溶出液的摩尔分数降至1 4以下·结果表明,此方法可以降低溶出液的摩尔分数,提高氧化铝的溶出率·     

低品位高硫铝土矿静态焙烧脱硫及溶出性能

以低品位高硫铝土矿为原料,通过静态焙烧-活化溶出技术路线,解决脱硫同时兼顾溶出性能。采取XRD,SEM和Materials Studio等手段,分析焙烧脱硫-活化溶出过程中氧化铝及一水硬铝石晶体转变,得出焙烧矿最佳溶出条件,对比分析原矿与焙烧矿溶出动力学。研究结果表明:焙烧促使一水铝石晶体减小,氧化铝晶体变大、结晶更加完整;当静态焙烧温度为600℃和时间为180 s时,焙烧后铝土矿中硫质量分数为0.29%,脱硫率为75.83%;在600℃焙烧90 s时,矿石最佳溶出条件为溶出温度280℃、溶出时间70 min、苛碱质量浓度为245 g/L、CaO添加质量分数10%,此时氧化铝相对溶出率为94.8%;正交实验结果表明影响氧化铝溶出率的主次因素排序为温度、CaO添加质量分数、时间、苛碱质量浓度;原矿与焙烧矿在溶出过程中其表观活化能分别为48.89 kJ/mol和63.99 kJ/mol,氧化铝溶出主要受内扩散控制;焙烧矿和原矿在特定溶出条件下氧化铝相对溶出率(y)与溶出温度(T)之间的关系分别为:y=u(T)=-372.59+2.800 53T-0.004 06T~2和y=u(T)=-563.42+4.324 69T-0.007 14T~2,以焙烧矿经验公式作为参数优化依据,在285℃时氧化铝溶出率为95.63%。     

拜耳法氧化铝的理论溶出率

本文根据一水硬铝石型铝土矿溶出赤泥的物相组成,导出了溶出一水软铝石——一水硬铝石型铝土矿和一水硬铝石型铝土矿的氧化铝理论溶出率计算公式。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.