用磁处理油酸钠溶液浮选钛铁矿及增效机理研究

研究了磁处理油酸钠溶液对钛铁矿和钛辉石浮选的影响.研究发现磁处理油酸钠溶液使钛辉石回收率由75.0%降至60.6%,钛铁矿回收率由75.2%降至69.3%;磁处理后的油酸钠溶液中钛铁矿和钛辉石的Zeta电位均正移,且钛辉石正移幅度较大,说明磁处理后油酸钠对钛铁矿的选择性增加.通过研究磁处理后油酸钠溶液的电导率、表面张力和光谱性质的变化揭示磁处理影响浮选的机理.磁处理后油酸钠溶液的电导率和表面张力增加,溶液中氢键作用减弱,促进了油酸根离子的释放,数量增多且得以释放的油酸根离子选择性吸附在钛铁矿表面,使钛铁矿和钛辉石之间的可浮性差异扩大.     

铁钛平行分选对微细粒钛铁矿强磁选的影响

采用"铁钛平行分选"工艺对高压辊磨超细碎的-3.2 mm钒钛磁铁矿进行选别实验,研究了强磁选对钛铁矿的分选效果.当磨矿细度为-74μm粒级占80%时,辊压产品选钛给矿的单体解离度较颚破产品高0.58%,辊压产品-19μm+11μm粒级中铁氧化物的单体含量较颚破产品低1.38%.与颚破产品采用"阶段磨矿-阶段分选"工艺相比,"铁钛平行分选"得到的强磁精矿中Ti O2的回收率提高5.11%,-19μm粒级的含量降低2.62%.不同粒级钛铁矿在分选空间中的受力分析表明,当粒度降低时,钛铁矿所受的比阻力急剧增加,而比磁力却有所降低,这增加了钛铁矿颗粒被磁场捕获的难度."铁钛平行分选"能够降低选别过程中微细粒钛铁矿的新生成量,改善钛铁矿的强磁选别效果.     

基于高强度调浆的钛铁矿浮选研究

以攀枝花钛选厂的强磁精矿为研究对象,通过浮选试验、浊度试验和扫描电镜分析,系统研究了高强度调浆对钛铁矿浮选的影响及其作用机制.研究发现,经捕收剂诱导疏水后,钛铁矿与钛辉石颗粒间容易发生异相团聚现象,细粒钛辉石随钛铁矿进入精矿产品,造成钛辉石的非选择性上浮.经高强度调浆处理,精矿TiO₂品位大幅提升.浮选指标由常规调浆处理时的精矿TiO₂品位39.97%,回收率78.09%,提升至精矿TiO₂品位43.79%,回收率79.28%.高强度调浆产生的流体力场能够消除钛铁矿与钛辉石颗粒间的异相团聚,强化钛铁矿与钛辉石颗粒间的分散状态,是高强度调浆提升钛精矿TiO₂品位的内在原因.     

磺化聚丙烯胺在钛铁矿和长石上的吸附特性和絮凝行为

用凝胶渗透色谱法(GPC)研究了人工合成高聚物磺化聚丙烯酰胺(PAMS)在微细粒钛铁矿和长石上的吸附特性及它们的絮凝行为;用光电子能谱(ESCA)和分子轨道(MO)理论研究了絮凝剂PAMS与钛铁矿和长石的作用机理;并根据絮凝剂与矿物作用的差别进行了微细粒钛铁矿、钒钛磁铁矿、长石矿料的絮凝分离试验. PAMS在矿物表面上的吸附量与其平衡浓度有线性关系.吸附量随平衡浓度增加而增加.在钛铁矿上的吸附量及吸附量强度均比长石大.分子轨道理论分析和光电子能谱证实PAMS的磺酸基在钛铁矿表面与过渡金属离子形成络合物;而在长石上是弱氢键作用. 采用一种新的工艺流程:选择性混合絮凝-磁选-超声波解絮凝-磁选可从含20.35％TiO_2及29.7％Fe的物料中选出钛铁矿精矿和钒钛磁矿精矿,品位分别为42.12％TiO_2,58.10％Fe;回收率相应为83％及90％.     

多粘类芽孢杆菌和红球菌对微细粒锡石可浮性影响研究

针对微细粒锡石浮选回收难问题,采用纯矿物浮选试验的方法,以多粘类芽孢杆菌和红球菌作为浮选捕收剂,研究了pH值、菌量、作用时间、菌培养时间、粒度等因素对锡石浮选回收率的影响规律。结果表明,多粘类芽孢杆菌对粒度小于13μm锡石浮选回收率最大为85.04%,对粒度为13～<38μm锡石的浮选回收率最大为75.03%。红球菌对粒度小于13μm锡石浮选回收率最大为72.77%,对粒度为13～<38μm锡石的浮选回收率最大为56.32%。多粘类芽孢杆菌对微细粒锡石的浮选效果普遍优于红球菌,且多粘类芽孢杆菌对细粒锡石(粒度小于13μm)具有更好的回收效果。扫描电镜和Zeta电位测试结果表明,多粘类芽孢杆菌和红球菌均可吸附在锡石表面上,改变了锡石的表面电位,影响微细粒锡石浮选回收率。     

倾斜式浮选柱用于超细粒煤脱灰的工艺研究

用倾斜式浮选柱对平均粒度小于15 μm的超细粉煤进行降灰的工艺试验研究,讨论了不同因素对浮选效果的影响.通过正交试验选择最佳工艺,用最佳工艺经过3次浮选得到灰分小于3%的超净煤.     

Ca2+对钛铁矿与钛辉石浮选行为的影响

以油酸钠为捕收剂,研究钛铁矿与钛辉石表面离子的溶出行为,并考察加入与脱除Ca2+对钛铁矿和钛辉石浮选行为的影响.研究结果表明:在浮选体系中加入Ca2+,对钛铁矿的浮选影响不大,但在碱性条件下活化了钛辉石的浮选;在浮选过程中,钛铁矿与钛辉石表面均有大量Ca2+溶解于矿浆中;脱除溶解离子后,钛铁矿的可浮性在弱酸性pH区间变化不大,在碱性pH区间明显变差,钛辉石在整个pH区间可浮性均变差;在脱除溶解离子后的矿浆体系中加入Ca2+,2种矿物在碱性矿浆环境下的可浮性都有所恢复;在碱性条件下,呈羧基络合物和氢氧化物沉淀形式存在的Ca2+吸附在钛辉石表面,使钛辉石表面油酸根离子的吸附活性质点增加,是Ca2+起活化作用的主要原因.     

氧化剂对低浓度硫酸溶解钛铁矿的影响

采用加入氧化剂和降低硫酸浓度等方法对传统的钛白粉生产工艺进行改进,探讨了氧化剂加入量、硫酸浓度、搅拌速度、反应时间等条件对钛铁矿酸解率的影响.通过正交实验获得了氧化剂对低浓度硫酸溶解钛铁矿的最佳工艺条件:KMnO4的加入量为钛铁矿质量的0.5％,硫酸浓度为60％,在600 r/min的搅拌速度下,控制温度为150℃后连续反应60 min.按这些工艺条件,钛铁矿酸解率可达到96％.     

LD泵浦NYAB晶体的激光自倍频特性

用LD作泵浦光源,在NYAB晶体上实现了1.06μm～0.53μm 的激光自倍频运转.泵浦(?)值功率为24.75mW,0.53μm 绿光最大输出功率2.2mW,最大转换效率为1.1%.     

超导配线的丝网印刷工艺研究

用硝酸盐热分解法制备Y-Ba-Cu氧化物高温超导微粉,与有机载体混合调配成超导浆料。用丝网印刷-烧结工艺,在高铝陶瓷基板上制得了厚约20～30μm,零电阻温度82K的厚膜超导电带。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the