天然铁矿石为氧载体的生物质化学链气化制合成气实验研究

在一个小型鼓泡流化床反应器上以Ar气为流化介质,对以天然铁矿石为氧载体的生物质化学链气化制合成气过程进行了研究。考察了反应温度对合成气组分、气体产率、碳转化率以及气化效率的影响,反应时间对合成气组分的影响;探讨了氧载体存在对生物质气化过程的影响。结果表明,天然铁矿石可以作为生物质化学链气化制合成气反应过程的氧载体,代替富氧空气或高温水蒸气作为生物质气化的气化剂;随着温度的升高,产物气体中CO、H₂的浓度逐渐增加,CO₂、CH₄浓度缓慢降低;随着反应时间的延长,合成气中H₂、CO、CH₄的相对浓度缓慢增加,而CO₂相对浓度逐渐降低;氧载体的存在能显著提高气体产率和碳的转化率及气化效率。扫描电镜-能谱(SEM-EDS)分析表明,当超过850 ℃时,铁矿石氧载体颗粒表面烧结现象明显,但反应前后,颗粒表面的成分及含量基本保持不变。     

拜耳法干式赤泥基本特性及堆场运行特征分析

拜耳法赤泥矿物成分特殊,力学性能较差,平果铝赤泥堆场利用拜耳法赤泥筑坝在国内尚属首次。通过对拜耳法赤泥颗分情况、矿物及化学组成、物理力学特性等进行试验研究,认为赤泥中Fe2O3含量较高、粒径较细且属于级配不良的土; 结合平果铝赤泥堆场目前的运行情况,分析了赤泥堆场目前运行时存在的排水系统、赤泥固结等几个问题,指出了赤泥堆场堆存后期有可能由于赤泥排水缓慢而导致堆场底部赤泥长期被水浸泡,从而对堆场的稳定性造成一定影响。     

Thermal Behavior of Galena Ore in Chlorine Atmospheres

The thermal behavior of a purified galena in a chlorine surrounding was determined. The kinetic of the chlorination of galena and the stoichiometry of this reaction between 723 to 973 K (450 to 700°C) were measured by thermogravimetry. The microstructural characterization of the solid residues were determined by SEM, EDXS and XRD. The ΔH _vap of the produced lead chloride volatilization was obtained by the application of Clausius-Clapeyron equation considering the process in an equilibrium state. This revised version was published online in July 2006 with corrections to the Cover Date.     

N-溴代丁二酰亚胺滴定法测定铁矿石中铁

铁矿石经盐酸溶解后,用Ｈ２Ｏ２氧化,使Ｆｅ＾２＋氧化成Ｆｅ＾３＋。加入过量的ＶＣ还原Ｆｅ＾３＋,剩余ＶＣ用ＮＢＳＭ滴定。方便简便,快速,终点敏锐,精了,准确度高,ＲＳＤ≤０．３％,相对误差〈０．４％,并可选择性地滴定矿石中的三价铁。     

影响进口铁矿中硫含量检测的重要因素

从北仑口岸进口的几种主要铁矿物相分析着手，讨论了铁矿的矿物组成对高频燃烧红外吸收法测定铁矿中硫含量的影响，为消除在个别矿种中硫的检测中存在的干扰提供理论依据。     

Mössbauer spectroscopy study of mechanically alloyed Fe2O3–(Al, Co and WC) systems

Mössbauer spectroscopy revealed that a central hyperfine interaction doublet and an additional sextet characterized the appearance of new phases in the mechanically alloyed Fe₂O₃–Al and Fe₂O₃–Co systems. In the Fe₂O₃–Al system, the intensity of the central super paramagnetic doublet which represents small particles of iron, increased with increasing milling time from 5 to 30 h of mechanical alloying. The magnetic sextet characterizing hematite vanished in the room temperature Mössbauer spectra of samples produced after 25 h of mechanically alloying the 50% Fe₂O₃ and 50% Al system. In general XRD peak broadening was observed as a result of extensive material structural distortion and formation of small particles. Fe, Al₂O₃ and mixed iron–aluminium oxide phases were identified in the XRD patterns with a small persistence of the iron oxide up to 20 h of mechanically alloying the 1:1 system Al–Fe₂O₃. In the 50% Co–50% Fe₂O₃ system, a 55% abundant new phase CoFe₂O₄ was observed, from the Mössbauer spectra of the system. The presence of this new phase was confirmed by the XRD analysis. The high energy ball milling of WC–Fe₂O₃ revealed a more effective grinding compared to hematite alone. The hematite particles were reduced to nanosized particles.     

用新显色剂PMNHA分光光度测定钒钛铁矿及其冶炼炉渣中的钒

建立了一个高选择性和简便的用显色剂N-苯基-1-甲氧基-2-萘甲酰氧肟酸(PMNHA)分光光度测定钒的方法。该试剂的三氯甲烷溶液能迅速地从2.25—4.50M盐酸中萃取钒(V)的紫色配合物。其配合物最大吸收在540nm,钒(V)与PMNHA的摩尔比为1:2,很多外来离子,特别是大量的钛不干扰钒的测定。钒含量在0—28ppm范围遵守比耳定律。本文拟定的测钒操作方法,简单、快速、准确,用若干标样核对,测得结果与推荐值很符合。     

Influence of particle size and mineral phase in the analysis of iron ore slurries by Laser-Induced Breakdown Spectroscopy

Laser-Induced Breakdown Spectroscopy (LIBS) was applied to the analysis of iron ore concentrates. The objective was to determine the influence of particle size and mineral phase on the LIBS signal. The LIBS spectra of hematite and magnetite ore concentrates were qualitatively indistinguishable from each other but magnetite yielded systematically less than hematite. This behavior could be set into an empirical equation to correct the iron peak intensities according to the level of magnetite in the analyzed sample. Similarly, an increase of the LIBS signal was observed as the particle size of the ore samples decreased. Again, an equation could be written down to correct the intensity of either iron or silicon in response to a variation of the average particle size of the ore concentrate. Using these corrections, proper response of the silicon signal against the concentration of silica in the samples was restored. The observed dependence of the strength of the iron signal upon the mineral phase is attributed to oxidation of magnetite into hematite.     

稀土矿石成分分析标准物质的研制

介绍两种稀土矿石成分分析标准物质的研制过程。采用X射线荧光光谱法检验标准物质的均匀性和稳定性，标准物质的均匀性和稳定性良好。由8家具有权威性的测试单位协同定值及对数据进行数理统计，确定了该标准物质的标准值及标准偏差。     

青海油砂矿的物理化学特性

油砂矿的物理、化学性质是其开发利用的关键因素之一 ;作者利用多种分析手段 ,揭示了青海出露油砂的特殊有机物化学组成与分布及其物理性质 ,其轻质组分含量很高 ,饱和烃含量高达近一半 ,而胶质、沥青质重组分含量低 (<38 % ) ,H和C原子比甚高 ,直链烷烃分布规整 ,主要集中在C19～C37 范围 ,物理参数处在普通重油范围内 ;该种物理、化学性质独特的出露油砂在全球为首次发现 ,是青海油砂矿特殊的地理地质环境所造成的 ,作者建议其开采宜采用钻井采油和露天开采依次进行的新组合方法