Investigation into rheological characteristic and foaming behaviour of molten slags

The rheological characteristic and foaming behaviour of molten slags have been investigated at different temperatures and with different additives, such as coke, coal and CaO. In the experiment of rheological characteristic, a modified rotational viscometer with variable revolution's speed was applied. Therefore, constitutive equations and rheological parameters of molten slags have been established. The tolerance-analysis method is applied to judge whether a molten slag belongs to Newtonian fluid or not. The results of foaming behaviour in the blowing gas show that addition of coarse grain coke and coal decreases the foam height. However, the carbonaceous materials of fine grain and CaO powder can cause the increase in foam height. It has also been found from the experimental results that the foam index ∑ is only available for slag of Newtonian fluid in blowing gas. The reason may be well explained with the rheological characteristic of molten slags.     

Minimum rate sampling and reconstruction of signals with arbitraryfrequency support

We examine the question of reconstruction of signals from periodic nonuniform samples. This involves discarding samples from a uniformly sampled signal in some periodic fashion. We give a characterization of the signals that can be reconstructed at exactly the minimum rate once a nonuniform sampling pattern has been fixed. We give an implicit characterization of the reconstruction system, and a design method by which the ideal reconstruction filters may be approximated. We demonstrate that for certain spectral supports the minimum rate can be approached or achieved using reconstruction schemes of much lower complexity than those arrived at by using spectral slicing, as in earlier work. Previous work on multiband signals have typically been those for which restrictive assumptions on the sizes and positions of the bands have been made, or where the minimum rate was approached asymptotically. We show that the class of multiband signals which can be reconstructed exactly is shown to be far larger than previously considered. When approaching the minimum rate, this freedom allows us, in certain cases to have a far less complex reconstruction system     

LF精炼过程中硫分配比和脱硫动力学方程研究

通过 ＬＦ精炼脱硫工业实验,确定了在不同条件下熔渣和钢水中的实际硫分配比．在二元碱度较高时,大部分实验数据与经验公式计算值相差近 ２－４倍 此外,用反应平衡计算的值要比实验数据大许多.在本实验条件下,脱硫速率和时间之间有较好的线性关系,脱硫传质系数为 ２．６７×１０－３ｃｍ／ｍｉｎ．该结果为ＬＦ炉生产中脱硫提供了必要的依据.     

HPLC测定聚丙烯餐具中12种抗氧化剂迁移量

目的建立高效液相色谱法,测定聚丙烯餐具中12种抗氧化剂的迁移量。方法采用蒸馏水、质量分数为3%的乙酸溶液、质量分数为10%的乙醇溶液、质量分数为20%的乙醇溶液、质量分数为50%的乙醇溶液、异辛烷、聚2,6-二苯基苯乙烷这7种食品模拟物浸提聚丙烯餐具中的12种抗氧化剂,经高效液相色谱-二极管阵列检测器测定,利用外标法进行定量。结果质量浓度为5.0~100.0 mg/L的范围内,12种抗氧化剂线性关系良好,R2≥0.9995,检出限为0.5~2.0 mg/L,平均回收率在87.1%~98.7%,相对标准偏差在0.8%~3.1%。结论利用HPLC法测定聚丙烯餐具中12种抗氧化剂的迁移量,该方法操作简便、快速、灵敏,可为食品接触材料中抗氧化剂分析提供参考。     

水中总有机碳溶液标准物质的研制

目的研制一种适用于相关检测仪器校准及分析方法评价的国家有证标准物质。方法经过标准物质原材料的选择、特性量值的测量方法、标准物质的制备方法、均匀性检验、12个月稳定性考察以及定值测量,并对样品的均匀性、测量的分散性及其他因素引入的不确定度分量分析和确定后,计算得到水中总有机碳标准物质测量过程不确定度的合成结果。结果水中总有机碳溶液标准物质的均匀性良好,稳定性优异,标准值定值结果为1000mg/L,相对扩展不确定度为2%。该标准物质已获批国家二级标准物质,编号为:GBW(E)082426。结论该标准物质性能良好,可满足食品、药品、日化、环境保护及化工产品研究和检测的需要,可用于相关仪器(总有机碳分析仪)的校准、分析方法评价,为统一相关量值发挥应有的作用。     

COREX喷煤不同喷枪的模拟试验研究

对同轴射流的套筒喷枪和交叉射流的斜插喷枪的流动特性进行了分析和对比。在COREX喷煤模拟燃烧炉内,对两种喷枪进行了喷煤试验。通过比较不同参数条件下喷吹煤粉的利用率,发现套筒式喷枪的效果要优于斜插冷却喷煤管喷枪。其原因是相同流速和流量条件下,同轴射流比交叉射流的行程要长,即煤粉与氧接触的时间长,因此套筒式喷枪有利于煤粉燃烧。     

安钢2200m~3高炉喷煤降焦生产实践

安钢2200m3高炉在精料的基础上,通过积极调整送风制度和装料制度,优化高炉操作,合理采用强化冶炼等措施,实现了焦比330kg/t、煤比160kg/t的生产指标,在喷煤降焦方面取得了新的进展。     

首秦1号高炉降低燃料比和提高喷煤比的工业实践

首秦1号高炉的技术装备、工艺水平、自动控制和环保节能等方面的新技术都达到了较高水平。高炉达到设计指标后,在原燃料质量不断提高的同时,采用技术创新与技术进步,解决了高炉单系统流程给生产带来的新问题,使得新技术、新装备能力达到较高水平,生产综合指标不断提高。实现燃料比低于492 kg/t,煤比高于180kg/t,在国内同类高炉中位于领先的水平。     

丰满大坝历年灌浆情况综述

丰满大坝运行之初渗漏严重,测到的最大渗漏量达16380L/min,为了防渗堵漏和降低坝体扬压力,对大坝进行了近60年的多次灌浆处理,本文综述了历次灌浆情况。     

基于烧结基础特性的新评价方法指导烧结配矿

 对国外10种常见的铁矿粉进行了研究,着重测试其烧结基础特性。考虑到以往烧结基础特性的评价指标忽视过程信息,使用模拟烧结过程中的单个因素指标对烧结基础特性指标进行定量描述的特点, 采用了一种全新的评价指标,该指标包含了烧结的过程信息,因此能较全面地对毅星粉的烧结基础特性进行评价。根据新方法对不同配矿方案的烧结杯试验结果进行预测,烧结杯试验结果证明了该预测的有效性,试验结果认为,巴卡粉与毅星粉在小比例配比条件下可进行互替。