铁矿石烧结料层温度模拟模型

以烧结理论为基础, 通过描述料层与抽风气体之间传热、传质过程, 建立以焦炭燃烧、碳酸盐的分解、水分的干燥与冷凝、混合料熔融与凝固等物理化学过程为基础的烧结料层温度模拟模型, 并设计开发了相应的铁矿石烧结料层温度模拟系统。该系统可以计算出任何时刻、任何高度料层及气体的温度, 模型计算结果与烧结杯实验结果准确率达90%。     

钒钛磁铁矿冷压含碳球团的粘结剂选择

为了提高钒钛磁铁矿冷压含碳球团的强度, 选用膨润土、糖浆及玉米面作粘结剂, 对比了3种粘结剂对球团性能的影响, 从而确定适合转底炉工艺的较优粘结剂及最佳配加量。结果表明: 膨润土加入量超过6%时, 制备球团性能能够达到转底炉工艺要求, 但导致球团内铁品位降低程度较大;添加糖浆作粘结剂时, 在实验研究范围内, 球团性能尚未达到工艺要求, 且存在压球过程中脱模困难问题;而选用玉米面作粘结剂制备球团时各方面都能达到工艺要求。玉米面(含量2.5%)加入到浓度为4%的NaOH溶液中发酵15 min左右, 所得球团的湿球落下强度为4.8次, 湿球抗压强度为55.1 N, 干球落下强度为24.8次, 干球抗压强度为648.1 N, 湿球爆裂温度为400 ℃, 满足转底炉生产的各项指标。     

真菌菌丝球HX对活性艳红X-3B的脱色作用

将培养的脱色菌HX菌丝球用于偶氮染料活性艳红X-3B的脱色,研究了培养时间、温度、pH值、培养方式及染料浓度对菌丝球脱色的影响。结果表明:菌丝球接入质量浓度为200mg/L的活性艳红X-3B培养基12h时,染料脱色率为44.6%,120h脱色率可达98.2%;温度为25℃,30℃和35℃时脱色率比较接近,35℃时的脱色率最大,达94.8%;染料培养基呈弱酸性时脱色率较高,pH值为5时,72h脱色率最高达91%;振荡培养较静置条件下的脱色率要高,两者在120h时的脱色率分别为98.2%和24.3%。     

温度对高磷鲕状赤铁矿含碳球团直接还原影响

对高磷鲕状赤铁矿含碳球团直接还原进行了研究。结果表明,1100℃以下时,提高温度可以显著提高球团金属化率;1100℃以上时,继续提高温度对球团金属化率影响不大。球团金属化率越高,磁选精矿铁品位越高。还原温度不仅显著影响球团的金属化率,还影响金属铁相的长大及磁选效果。因此,控制适宜的温度对高磷鲕状赤铁矿含碳球团直接还原至关重要。     

新型黏结剂强化冷固结球团的作用机理

 黏结剂在冷固结球团中必不可少,目前广泛使用的冷固结球团有机、无机黏结剂如CMC、膨润土和水泥等均会在高温下失效,导致球团高温强度严重下降,因此,寻找一种高温强度良好的黏结剂是目前需要解决的问题。采用新型黏结剂制备冷固结球团,通过XRD和SEM-EDS等对新型黏结剂球团制备原料及球团性能特征进行分析,同时探讨黏结剂对球团冷态抗压强度及高温强度的影响及其作用机理。试验结果表明,黏结剂以流动状态存在于冷固结球团中,可有效吸附或包裹铁矿粉颗粒,增加黏结剂配比可同时提高球团的冷态抗压强度及高温抗压强度;在高温还原性气氛下焙烧冷固结球团,由于发生还原反应,球团金属化率提高,铁矿粉颗粒间空隙增大,导致球团强度下降,焙烧时间为30～90 min时,球团金属化率及抗压强度变化趋势最明显;焙烧初期,球团抗压强度不会发生快速下降,且焙烧结束后球团强度仍可保持为100 N/个左右。     

MgO、TiO2对镁质钒钛球团矿综合冶金性能的影响

 以球团厂实际配矿为基础,选取铁矿粉OA、OB、OC和OD,以膨润土作为黏结剂进行试验分析MgO和TiO2对镁质钒钛球团矿冶金性能的影响,并得出合适的TiO2质量分数和MgO质量分数,为生产镁质钒钛磁铁矿球团提供理论依据。结果表明,当[w(MgO)]从1.25%升高到2.34%,球团矿抗压强度从2 511降低到2 453 N/P,还原膨胀指数降低了13.17%;当[w(TiO2)]从3.97%升高到5.07%,球团矿抗压强度从2 511降低到2 383 N/P,还原膨胀指数略有下降,影响较小。球团矿中的[w(MgO)]从1.32%升高到2.38%,球团矿的熔融温度区间降低了40%,改善了其熔滴性能,但MgO固溶体等难还原矿物降低了球团的还原度指数。球团矿综合冶金性能最优的配比参数（质量分数）为OA矿粉50%、OB矿粉21%、OC矿粉10%、OD矿粉19%和膨润土1.8%。     

高铁煤泥作还原剂直接还原褐铁矿研究

以高铁煤泥为新型还原剂, 直接还原褐铁矿。通过与无烟煤对比, 探索了还原剂用量、还原温度和还原时间对褐铁矿直接还原的影响。采用X射线衍射(XRD)和扫描电镜(SEM)等手段, 研究了褐铁矿原矿及其煤泥球团在不同温度下的物相和形貌。结果表明：煤泥用量25%, 经1 200 ℃直接还原20 min后, 可得到金属化率 86.4%的金属化球团。在直接还原反应中, 不仅包括铁氧化物向金属铁的还原, 而且存在中间产物与脉石反应生成铁橄榄石和铁尖晶石再还原生成金属铁, 金属铁在产物中主要以金属铁颗粒的形式存在, 渣铁相界面分明, 最佳状况下渣相中检测不到铁氧化物, 煤泥中的铁氧化物随反应的进行被还原为金属铁, 一定程度上提高了球团金属化率。     

接枝ABS和AS掺混生产ABS树脂技术

综合叙述了接枝ABS粉料和AS珠粒料树脂掺混生产ABS树脂技术。     

An assessment of granular urea/ammonium sulphate and urea/potassium nitrate fertilizers on nitrogen recovery by ryegrass

The comparative effects of ammonium sulphate (AS), potassium nitrate (KNO₃), urea (U) or combined 1:1 (w/w) U/KNO₃, U/AS granular products were investigated on dry matter (DM) yield and¹⁵N utilisation by perennial ryegrass grown under controlled environmental conditions.The DM yield and apparent N recovery with the single N sources was in the order KNO₃ > AS > U. The¹⁵N budget in shoots, roots and soil indicated that only 55% of the urea N was recovered at the end of the experiment compared with 87% and 86% for AS and KNO₃ respectively. The DM yield and apparent N recovery from the combined U/AS source was significantly higher than would be expected (P < 0.01) based on the proportions of each N source in the mixture. Differentially labelling the U and AS with¹⁵N indicated that AS enhanced the shoot % utilisation of urea by 38% (P < 0.001) whereas urea reduced the shoot % utilisation of AS by 14% (P < 0.01). These results indicate that an interaction occurred between U and AS when combined in a 1:1 (w/w) ratio in the same pellet.     

Comparison of release devices for stoat (Mustela ermined) semiochemicals used as montane vole (Microtus montanus) repellents

Fenced enclosures were used to simulate peak populations of montane voles (Microtus montanus) for field bioassays of a stoat (Mustela erminea) scent mixture in various controlled-release devices. A 1 1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane was dispensed in capillary tubes, clay pellets (activated alumina), rubber septa, and plastic rope. Release devices were placed near, or attached to, young apple trees planted in blocks in two enclosures containing high populations of voles. The stoat scent mixture in rubber septa and plastic rope significantly reduced vole attack of trees compared with a control, pellets, and capillary tubes. In terms of complete girdling (tree mortality), this odor in septa and rope also significantly reduced feeding compared with the control, and the rubber septa formulation was more effective than either the pellets or capillary tubes. Fenced populations of voles may be used effectively to conduct field bioassays during low years in vole cycles. Variations of release devices (with this stoat scent mixture) based on rubber septa for broadcast application to depress vole population density and survival, and plastic rope attached to individual trees to generate an avoidance response, should be used for forest and agricultural crop protection.