红土镍矿选择性还原-熔分制备镍铁合金

以硅镁型红土镍矿为原料,采用金属化焙烧-熔分工艺,通过正交试验制备金属化球团,将所得金属化球团在1500℃条件下熔融分离30min提取镍铁合金,考察影响因素对实验结果的影响.结果表明:在选择性还原制备金属化球团过程中,对金属化率的影响程度从大到小的因素依次是C/O摩尔比、焙烧温度、焙烧时间和碱度;实验可获得镍品位19%的镍铁合金;在碱度为0.8~1.2范围内,S和P分配比随着碱度的升高而增大.利用X射线衍射和扫描电镜对金属化球团及熔融分离出的渣进行微观分析,发现加入的石灰石与复杂矿相反应可释放出简单镍氧化物和铁氧化物,促进还原反应的进行,当石灰石不足时,少量铁以Fe3+的形式存在于铁金属化率70%的金属化球团中.     

钒钛磁铁矿直接还原试验研究

在热力学分析的基础上研究了实验室条件下钒钛磁铁矿配煤直接还原的特点,考察了还原机理及还原温度、反应时间和配碳量对金属化率的影响.结果表明:采用直接还原可使钒钛磁铁矿中铁的氧化物优先还原为金属铁,钛仍以氧化物的形态存在;随着温度升高,球团金属化率呈上升趋势,且上升趋势随之减缓;在xC/xO=0.9∶1时,延长反应时间金属化率增加,但反应时间过长金属铁会被再氧化,反应时间控制在20 min为宜;在xC/xO=1.1∶1时,40 min内未出现再氧化现象;低配碳(xC/xO=0.8∶1)时,球团的金属化率随还原时间、还原温度的增加而增加,1 300℃下还原10 min后金属化率即达到了90%以上.     

津布巴铁精矿含碳球团还原实验研究

高炉炼铁工艺中炼焦、球团、烧结工序是主要污染源,本实验模拟转底炉工艺采用煤粉为还原剂实现直接还原铁的清洁生产。实验以津布巴铁精矿为原料,对该铁精矿进行XRD分析、扫描电镜分析和热失重分析。实验采用含碳球团焙烧还原工艺,通过四因素三水平正交实验研究各因素对焙烧球团的金属化率的影响。结果表明:在含碳球团焙烧还原过程中,对金属化率的影响程度从大到小的因素分别为焙烧温度、碱度、焙烧时间和配碳量,其中,当配碳量为1.0,温度为1 150℃,碱度为0.37,焙烧时间为25 min是得到高金属化率焙烧球团的最佳条件,球团焙烧后的残炭量与焙烧温度和碱度也有较大关系,最终球团金属化率均在80%以上。     

钒钛磁铁精矿的预氧化研究

研究了钒钛磁铁精矿在等温预氧化条件下的物相组成及其转变情况,并将钒钛磁铁精矿原矿和预氧化后的样品以煤粉为还原剂进行直接还原,利用XRD和ICP-AES对产物进行物相和成份分析.研究结果表明:预氧化能够加速还原过程,提高金属化率,较为适宜的预氧化条件为:预氧化温度为900℃,预氧化时间为30 min;预氧化矿在1 200℃下还原60 min,比钒钛磁铁精矿原矿金属化率提高了14.0%.其强化还原的机理是:在预氧化过程中Fe3O4被氧化成Fe2O3,FeTiO3被氧化成Fe2O3.FeTiO3固溶体、Fe2O3和TiO2,破坏了钒钛磁铁精矿的结构,矿粉内部形成了大量孔隙,改善了还原反应的动力学条件,加速了还原过程.     

红土镍矿焙烧过程中的矿相转变及其对气体还原的影响

研究了印度尼西亚红土镍矿焙烧过程中的矿相转变过程以及焙烧温度对混合气体 (V (CO) : V (O₂)=50 : 50)还原的影响. 采用差热/热重分析(differential scanning calorimeter/thermal gravimetric, DSC/TG)、比表面积分析法(Brunauer Emmett Teller, BET)、X射线衍射(X-ray diffraction, XRD)、扫描电镜(scanning electron microscope, SEM)等方法综合考察了各因素对红土镍矿焙烧过程及其对后续还原的影响. 结果表明: 在焙烧阶段, 红土镍矿中的针铁矿在 300°C 左右脱除结晶水形成赤铁矿, 600~700 °C时蛇纹石分解形成无定形态硅镁酸盐, 且当温度继续升高时无定形态硅镁酸盐会结晶形成橄榄石; 利用混合气体 (V (CO) : V (O2)=50 : 50)还原红土镍矿时, 随着焙烧温度的升高, 镍和铁的金属化率也逐渐升高, 经700°C焙烧后, 还原产物镍的金属化率最高可达86.81%, 但是当焙烧温度超过橄榄石结晶温度时则不利于红土镍矿的还原, 镍的金属化率降至66.73%.     

矿壳内配碳球团试制金属化球团的实验室研究

矿壳球团在带式焙烧机上焙烧还原是一种投资少、成本低的生产高炉金属化球团的直接还原法。本文从理论上分析了矿煤球团用铁精矿（加添加剂）包壳所具有的优点，并介绍在实验室研究矿壳球团的配碳量、用铁精矿包壳时添加剂种类和用量、最高还原焙烧温度和升温速度、还原焙烧气氛等因数对金属化球团强度和金属化率的影响。     

钒钛磁铁精矿直接还原反应行为及其强化还原研究

通过在钒钛磁铁精矿中添加还原煤粉和少量添加剂,研究了还原温度、还原时间和添加剂等因素对钒钛磁铁精矿金属化率的影响,并对添加剂强化还原机理进行了探讨.结果表明:还原温度、还原时间、碳铁摩尔比及添加剂对金属化率的影响较大.在还原温度1200℃、还原时间120 min的条件下,未添加添加剂时金属化率最高可达84.5%;添加质量分数3.0%Na2CO3或CaF2的条件下,钒钛磁铁精矿的金属化率可以分别达到96.5%和93.3%.     

钒钛磁铁矿含碳球团还原的影响因素

通过单因素实验考察了还原温度、还原时间及碳氧摩尔比（nC/nO）对钒钛磁铁矿含碳球团还原的影响,结合扫描电镜照片解释了钒钛磁铁矿的还原机理.实验结果表明,适当升高还原温度、延长还原时间及增加碳氧摩尔比均可以促进钒钛磁铁矿的还原,并且金属化率随还原温度的升高先急剧升高而后趋于平缓,随着还原时间的延长及碳氧摩尔比的增加而先升高后降低,而残碳量随着反应的进行不断降低.当还原温度为1350℃,还原时间为30 min,碳氧摩尔比为1.2时,球团的金属化率达到最大值.通过扫描电镜照片可以看出,球团在还原过程中形成了铁连晶,并且在不同的还原条件下铁连晶的大小及形态不同.     

高铬型钒钛磁铁矿煤基直接还原研究

将高铬型钒钛磁铁精矿、还原剂煤粉和黏结剂按一定比例配料、混匀、模压成型后进行直接还原,研究了煤种、碳氧摩尔比(COR)、还原温度、还原时间和添加剂等因素对高铬型钒钛磁铁精矿还原产物金属化率的影响,采用X射线衍射对还原产物进行物相分析.结果表明:以无烟煤为还原剂,碳氧摩尔比1.2、还原温度1 350℃、还原时间60 min的条件下,未采用添加剂时产物金属化率最高可达89.80%;在碳氧摩尔比1.2、还原温度1 250℃、保温时间30 min、添加质量分数为3%Ca F2条件下,还原产物金属化率达85.27%,有效降低了还原过程的能耗.还原温度低于1 250℃时,产物主要物相为金属铁,同时还有少量的Fe2O3,Fe3O4,Fe3C,Fe0.5M g0.5Ti2O5和Ti O2;1 300℃时,还原产物中出现Fe2VO4;高于1 350℃时,还原产物中出现了(Fe,Cr)和Ti3O5.     

含铌铁精矿含碳球团还原过程中微观结构变化研究

借助SEM、EDS、XRD、化学分析等手段,对不同还原焙烧条件下含铌铁精矿含碳球团的金属化率、形貌、物相组成及元素分布等进行表征,在实验室模拟转底炉条件下研究了直接还原过程中铁矿物和钛、铌矿物的微观结构变化。结果表明,适当地提高还原温度或延长还原时间,有助于提高球团的金属化率,本实验条件下,在还原温度1100℃时保温20min,球团金属化率达到最大,约为86%;此外,随着还原温度的升高或还原时间的延长,金属铁不断聚集、长大,形成较大的金属颗粒,并逐渐连结形成网状结构,渣铁明显分离,含铌、钛矿物也聚集在一起分布在渣相中,为后续铌和钛的富集提供了有利条件。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-