现代高炉注入焦炉煤气增强铁矿石烧结矿还原性

Elsayed Abdelhady MOUSA,1)* Alexander BABICH2)and Dieter SENK2)* 冶金研究和开发研究所(CMRDI), P. O. Box 87-Helwan, Cairo, 埃及 黑色冶金系 亚琛工业大学 Intzestr. 1, 52072 Aachen, 德国 (2013年3月15日收到;接受5月22日,2013)

Energy network within the integrated steel works should be used more efficiency to reduce the energy consumptions and CO2 emissions.

能源网络综合钢铁厂内应该使用更多的效率,减少能源消耗和二氧化碳排放。 大型钢铁厂应用网络资源提高能源效率，减少能源消耗和二氧化碳排放

The injection of free resources of coke oven gas (COG), which is rich with hydrogen, into the modern blast furnace is one of such measures.

免费资源的注入焦炉煤气(齿轮),这是与氢丰富,融入现代高炉是此类措施之一。 注入富氢的焦炉煤气是现代高炉采用措施之一。

In order to clarify the effect of COG injection on the reduction processes in the blast furnace; iron ore sinter was isothermally and non-isothermally reduced with different gas compositions at different temperature.

为了澄清焦炉煤气注射对还原过程的影响在高炉;铁矿石烧结是等温地和不等温地不同气体成分在不同温度降低。

为了弄清焦炉煤气注射对高炉中还原过程的影响，等温地和不等温地不同气体成分在不同温度下铁矿石烧结。

The gas compositions were selected to simulate the conditions of middle (150 m3/tHM) and intensive (300 m3/t HM) injection of COG into the blast furnace.

气体成分被选来模拟条件的中产(150立方米/吨铁水)和密集注入(300立方米/吨铁水)的焦炉煤气高炉。 模拟条件中密集注入高炉的焦炉煤气的气体成分选用(150立方米/吨铁水)和(300立方米/吨铁水)。 The results were compared to that obtained under typical blast furnace conditions without COG injection. 获得的结果相比,在典型高炉条件下没有焦炉煤气注射。

获得的结果与没有焦炉煤气注射的典型高炉条件下获得的结果比较。

The isothermal reduction at 900–1 200°C indicated the enhancement of the reduction rate as COG injection increased.

等温还原900 - 1200°C表示减速率的提高焦炉煤气注射增加。 900 - 1200°C时的等温还原表示增大焦炉煤气注射时的还原速度。

The non-isothermal reduction indicated the efficiency of intensive injection of COG in decreasing the direct reduction from 50% to only 5% at 1 200°C.

艰苦的注入效率的非等温还原显示齿轮在减少直接从50%减少到只有50%在200°C。 在1200°C下的非等温还原表示密集注入焦炉煤气效率还原从50%直接减少到只有5%

Reflected light microscopy, scanning electron microscopy and X-ray techniques were used to characterize the micro-structure and the developed phases in the origin and reduced sinter.

反射光显微镜、扫描电镜和x射线技术被用来描述微观结构和发达阶段的起源和降低烧结。 反射光显微镜、扫描电镜和x射线技术被用来描述微观结构，发展阶段的起源和降低烧结。

The rate controlling mechanism of sinter under different conditions was predicted from the correlation between apparent activation energy calculations and microstructure examination.

烧结矿的速率控制机制在不同条件下从表观活化能的计算和微结构规范。 从不同条件下表观活化能的计算和微结构规范预测烧结矿的速率控制机制。

KEY WORDS: integrated steel plant; COG; hydrogen; CO2 emissions and gaseous reduction 关键词:综合钢铁厂;焦炉煤气;氢气;二氧化碳排放和减少气体

1. Introduction 前言

The iron and steel industry is one of the main branches responsible for energy consumption and CO2 emissions. 钢铁行业是一个负责能源消耗和二氧化碳排放主要分支机构。

Despite remarkable decrease in specific CO2 emissions from the steelmaking in the industrial countries, the total amount of CO2 emissions is growing across worldwide due to the continuous increasing of steel production reached to about 1.5 billion ton in 2011.

尽管在特定的二氧化碳排放量显著降低炼钢工业国家,全球二氧化碳排放的总量增长在由于连续增加约15亿吨的钢铁产量达到2011.

2011年，尽管特定的二氧化碳排放量显著降低炼钢工业国家的二氧化碳含量,但是由于钢产量的不断增加

1)

达到了15亿吨左右全球二氧化碳排放的总量仍在增长。

Nowadays the steel industry faced increasing demand to minimize the energy consumption and gas emissions especially from ironmaking processes.

如今钢铁行业面临越来越多减少能源消耗和气体排放的需求，特别是从炼铁流程方面。

The efficient use of byproduct gases is essentially important for the profitability of steel mill operation due to the high energy volumes and the costs involved.2)

由于高耗能和高成本，气体副产品的有效利用本质上是对钢厂的盈利能力的重要操作。2)

The injection of COG into the modern blast furnace is one of effective measures for iron and steel industry to achieve low-carbon ironmaking, energy saving and emission reduction.3)

向现代高炉注入焦炉煤气是钢铁行业实现低碳炼铁，节能和减排有效的措施之一 。3)

The specific amount of generated coke oven gas by conventional coke making is in the range from 410 to 560 Nm3/t of coke depending on the volatile matters in the coal charge.4)

特定的焦炉煤气是根据煤的挥发性通过传统的炼焦得到，生成的量在410到560Nm3/吨的焦炭。4)

In 2011, the worldwide coke production reached a new record of 1.4 million tonnes with COG amounted to be more than 310 billion Nm35,6)

2011年，世界焦炭生产达到了6.414亿吨的新记录，焦炉煤气超过3100亿Nm3。5,6)

The COG is currently used after its cleaning from tar, naphthalene, raw benzene, ammonia, and sulfur for heating of blast furnace stoves, ignition furnaces in sintering plant, heating furnace in rolling mills and electric power generation in power plant.6,7)

目前焦炉煤气使用是从焦油清洗后，萘，原料苯，氨，硫 for 高炉炉的加热 灼烧炉 在烧结厂，加热炉在轧钢厂 发电 在电厂

目前所使用的焦炉煤气经焦油、萘、粗苯、氨、硫磺清洗，用在高炉的加热,烧结厂熔炉点火,轧钢厂加热炉,电厂发电。6,7)

The estimations which carried out on optimizing the energy consumption in the integrated iron and steel works

1)

indicated that the utilization of COG for power generation is not always the optimal credits.4)

经过对钢铁工业的能源消耗的估计进行优化表明,焦炉煤气用于发电并不是最佳的用处。4)

The COG is consisting of e.g. 58% H2, 27%CH4, 7% CO and small amount of CO2, N2, and other elements.9) 例如，焦炉煤气包括58%氢气,27%的甲烷,7%一氧化碳和少量的二氧化碳,氮气和其他元素。9)

This composition of COG which is rich with hydrogen has attracting much attention in the recent years for its

–

utilization in the reduction processes.811)

–

最近几年，富氢的焦炉煤气在还原过程中的利用率吸引了太多的关注。811)

The flexibility of COG utilization in the integrated steel plant for DRI production through the addition of Midrex process is expected to be very efficient. 12)

综合钢铁厂在米德雷斯直接炼铁法中灵活的加入焦炉煤气生产的直接还原体，对焦炉煤气的利用率的预期是非常有效的。12)

Also the injection of COG into the blast furnace contributes of decreasing the energy consumption and CO2 emissions.

齿轮的注入到高炉的贡献减少能源消耗和二氧化碳排放

焦炉煤气注入到高炉为降低能源消耗和二氧化碳排放的贡献。

The injection of COG into the blast furnace has influence on the raceway conditions and iron ore reduction. 高炉中注入焦炉煤气会影响水沟和铁矿石还原条件。

The mathematical modelling on the injection of COG into the blast furnace tuyeres indicated better combustion

–

conditions and higher injection rate by using two injection lances compared to one lance.1315)

在焦炉煤气注入的数学模型中高炉使用两个注入喷和一个喷相比较，风量取值表示更好的燃烧条件和

–

更高的注入量。1315)

The combustion of COG hydrocarbons in the front of tuyeres by blast oxygen results in a development of carbon monoxide and hydrogen gases which increase the potential of reducing gas on account of N2.13) 在风口前面鼓氧焦炉煤气碳氢化合物的燃烧 一氧化碳和氢气 气体的发展 增加减少天然气的势 由于氮气

焦的燃烧炉煤气碳氢化合物在前面爆炸风量取值的氧气导致发展的一氧化碳和氢气气体增加的潜力减少天然气的氮气

The theoretical calculation and commercial trails which carried out on the replacement of natural gas with coke oven gas in blast furnace showed lower coke con-sumption and higher hot metal production.16)

理论计算和商业轨迹表明高炉中焦炉煤气替代天然气的降低焦炭的消耗，提高的热金属生产。16)

理论计算和商业轨迹进行天然气的替代与焦炉煤气高炉显示更低的可口可乐消费和更高的热金属生产。

The high efficiency of COG is due to the fact that it contains 3.5–4 times fewer hydrocarbons compared to that of natural gas.17)

焦炉煤气的效率高是由于绿茶中含有3.5 - 4倍减少碳氢化合物相比,天然气 它包含更少的碳氢化合物 相比,天然气

焦炉煤气的效率高是由于它包含比天然气少3.5 - 4倍的碳氢化合物。17)

This improves the combustion in the tuyere hearth, activate coke column, and increase gases utilization in the furnace.

这提高了炉风口的燃烧,激活焦炭塔,增加炉气体的利用率。

It has been noticed higher amount and higher heating value of blast furnace top gas could be generated through COG injection into the blast furnace.16)

它已注意到高量和较高的高炉炉顶煤气发热值可以通过注射入高炉煤气。

已经注意到更高数量和更高的高炉炉顶煤气热值可以通过焦炉煤气注入高炉产生。16)

Although the injection of COG into the blast furnace is practiced in some countries with different injection rate from about 30 to 280 m3/t HM but its effect for example on the sinter reducibility is not clear.9,11,18,19)

虽然一些国家对焦炉煤气在高炉内注射实行不同注射速率从约30至280立方米/吨铁水，但对烧结矿的还原性效果不明显。9,11,18,19)

Furthermore, it was reported that the maxi-mum level of COG injection at the blast furnace tuyere is thought to be 0.1 ton COG/t hot metal according to the ther-mochemical conditions while the replacement ratio is 0.98 ton of coke/t of COG.20)

此外，据报道，根据热化学条件置换率为0.98吨焦炭/吨焦炉煤气，高炉风口焦炉煤气最大水平注射量被认为是0.1吨焦炉煤气/吨铁水。20)

The current study aims at investigation of the influence of COG with different injection levels into the blast furnace on the reduction kinetics and mechanism of iron ore sinter.

目前研究的目的是探索高炉煤气在不同水平注入下的还原动力学和铁矿石烧结机理。

The gas compositions are selected to simulate experimentally the results of numerical analysis method based on raceway mathematical model, multi-fluid blast furnace model, and exergy analytical model.3)

基于回旋区数学模型，多流体高炉模型,火用分析模型,选择数值分析方法分析模拟气体成分实验的结果。3)

In the base case, PC is injection into the blast furnace (145 kg/t HM). By COG injection, PCI is decreased while oxygen enrichment is increased to main-tain a constant flame temperature. 在这样的情况下，电脑注射入高炉（145公斤/吨铁水）。焦炉煤气注射，PCI降低，富氧增加保持恒定的火焰温度。

In order to clarify the influence of COG injection on the reduction processes; the results are compared with that obtained under typical blast furnace conditions without COG injection.

为了阐明焦炉煤气注射对还原过程的影响，其结果与典型的高炉条件下获得无焦炉煤气注射相比。

The reduction has been carried out isothermally at temperatures in the range of 900–1 200°C. 在900 -1 200°C的温度范围进行等温还原反应。 减少进行了等温地在温度范围900 - 1200°C。

On the other hand the non-isothermal reduction was carried out under continuous variation of gas compositions and heating rate simulates the blast furnace conditions with different amount of COG injections.

另一方面，非等温还原反应在模拟高炉不等量焦炉煤气注射，气体的组合物和加热速率连续变化的条件下进行。

The structure and morphological changes of original and reduced sinter were intensively studied and correlated with the reduction kinetics and mechanism.

原来和降低烧结的结构和形态的变化是深入研究还原反应的动力学和还原机理。 的结构和形态变化和降低烧结原深入的研究和与还原的动力学和机理。 2. Experimental Techniques 2.实验技术

The reduction of industrial iron ore sinter has been carried out using a laboratory system as shown in Fig. 1. 工业铁矿石烧结还原已使用实验室系统如图1所示进行

The system consisted of vertical tube Tammann furnace connected with an automatic sensitive balance. 该系统由垂直管Tammann炉连接自动敏感天平。

Alumina reaction tube was fitted inside the graphite heating tube where the heat transferred mainly by radiation to the sinter samples.

氧化铝反应管安装石墨管加热，热传递主要是通过对烧结的样品的辐射。

The holey alumina crucible containing samples were hold by a Pt wire and connected to a balance for continuous measuring of the weight loss as a function of time.

多孔氧化铝坩埚含有样品经铂丝连接到一个测量作为时间的函数连续减轻体重的天平。

With a pneumatic cylinder, the crucible containing the sinter samples were lifted up and down within less than 1.0 second into the furnace.

应用气动缸，在小于1秒内将装有烧结样品的坩埚升降到到Tammann炉。

The temperature was measured with platinum thermocouple which fixed near to the sample. ，测定样品固定在温度的铂热电偶。 样本固定在测量温度的铂热电偶附近。

For isothermal reduction; purified N2 with flow rate of 1.0 liter/min was purged in the reaction tube from the bottom during the heating up of the furnace to the pre-determined temperature.

等温还原;净化N2流量的1.0升/分钟清除在反应管从底部在预先确定的炉的加热温度。 等温还原；在预定温度下用流速1升/分钟的高纯氮气在反应管底部吹扫加热炉。

At the applied temperature, the sinter pieces with average size 8–10 mm and average weight 20 g were placed in the alumina crucible (diameter = 30 mm, length = 40 mm)and centered in the middle of hot zone in the furnace. 应用温度下,烧结块放置在氧化铝坩埚(直径= 30毫米,长度= 40毫米)中，平均大小8 - 10毫米,平均体重20克，集中在炉的加热区。

After soaking the sample at this temperature for 10 minutes, a reducing gas simulated the base condition without COG injection, middle COG injection (150 m3/tHM), and intensive COG injection (300 m3/tHM) as given in Table 1 is purged into the reduction alumina tube with flow rate of 4.0 liter/min.

样品在此温度下浸泡10分钟后，模拟还原气体在基础条件无焦炉煤气注入，中间焦炉煤气注射（150立方米/ 吨铁水），和密集的焦炉煤气注射（300立方米/ 吨铁水）如表1中给出的是清除进入氧化铝管中还原体流速4升/分钟。

浸泡后的样品在这个温度为10分钟,减少气体模拟基础条件没有齿轮注射,中间齿轮注射(150立方米/三卤

甲烷),和密集的齿轮注射(300 m3 / tHM)如表1给出了清除到减少氧化铝管流量的4.0升/分钟。

The conditions of base, middle COG injection, and intensive COG injection will be referred hereafter as case 1, 2 and 3; respectively.

基础的条件，中间注射焦炉煤气，密集注射焦炉煤气将分别简称案例1，2和3。 基条件、中间齿轮注射和密集的齿轮注射以后将被称为用例1、2和3,。分别

These scenarios are selected based on the results of simulated blast furnace with COG injection.3) 这些场景选择结果的基础上模拟高炉与齿轮注射。

这些场景都是根据模拟高炉与焦炉煤气注塑选择的结果。3)

The gas composition of case 1 corresponds to the typical blast furnace operation with about 145 kg/tHM PCI and about 3% oxygen enrichment.

案例1的气体成分对应于典型的高炉操作与约145公斤/ tHM PCI和富氧3%左右。 例1中的气体组合物对应于典型的高炉操作约145公斤/ 吨铁水 PCI和3%氧富集。

The gas composition of case 2 and 3 corresponds to the blast furnace operation with middle and intensive COG through the decreasing of PCI to 115 and 85 kg/tHM and increasing the oxygen enrichment to 19 and 38% respectively.

例2和3的气体成分对应于的高炉操作中间和密集的焦炉煤气通过PCI的降低到115和85千克/吨铁水和分别增加富氧至19%和38％。

气体成分的案例2和3对应于高炉操作中密集的COG通过PCI 115和85公斤/ THM和增加氧浓度分别为19和38%的减少。

案例2和3的气体组成，通过PCI的降低到115和85千克/吨铁水和分别增加富氧至19和38％对应的高炉操作中，密集的焦炉煤气。

The time was accounted for 150 min in all isothermal reduction tests. 在所有等温还原试验的时间里占150分钟。

For non-isothermal reduction; similar flow rate, size and weight of sinter which used in the isothermal reduction was applied while the gas composition was changed for cases 1–3 as given in Table2.

对于非等温还原，采用和等温还原相似的流量、尺寸和烧结重量，例1-3中气体成分在表2中已给出的。 非等温还原;流量相似,大小和重量的烧结使用的等温还原应用在气体组分变化情况在表1 - 3。 非等温还原；相似的大小和流量，在等温还原使用烧结重量时气体成分为例1–3中给出的表了。

The heating rate starting from room temperature up to 1 200ºC was selected to simulate the blast furnace conditions and fixed for all cases.

加热速率从室温到1 200ºC选择模拟高炉条件和的

加热速率从室温到1 200ºC选择模拟高炉条件和固定的所有情况。 所有例子模拟的高炉升温速率都是从室温到1200ºC并且固定。

加热速率从室温开始至1200℃被选择来模拟高炉条件和固定的所有情况。

The total time was 240 min in all non-isothermal experiments.

总时间为240分钟在所有非等温实验。 什么的总时间？？？？？？？？？

在所有非等温实验中总时间是240分钟。

During the reduction experiment, the weight loss was continuously recorded as a function of time. 在还原试验中，连续记录损失的重量，损失的重量为时间的函数。

At the end of experiment, the reduced sinter was lifted up and putted in a closed chamber under high flow rate of Ar to avoid the reoxidation during cooling.

实验结束时，降低烧结矿被举起，放在高流量的Ar，避免在冷却过程中的再氧化在封闭室。

在实验结束时，还原的烧结矿被举起和推到一个封闭高流速的Ar的腔室内，以避免冷却过程中的再氧化。

For partial reduction, the oxygen weight loss required to achieve a certain reduction extent was pre-calculated and the reaction was stopped when the weight loss reached the predetermined value.

对还原的部分，氧气重量的损失在一定程度范围内是经过预先计算，并且当减重达到预定值后停止反应。 The total reduction degree was determined depending on the calculation of oxygen represented in iron oxides of sinter.

总的还原程度取决于烧结矿中的铁氧化物中氧气的计算。

Table 1 Composition of the applied reducing gases in isothermal trials. 表 1 等温试验所施加的还原性气体的组成

CO,

vol.%

例1：普通条件 例2：中间焦炉煤气

45

(150 m3/t HM) 例3：密集注入焦炉煤气

55

(300 m3/t HM)

35

10

0.

0.39

20

35

0.44

0.31

37

vol.% 8

vol.% 55

0.22

H2,

N2,

H2/CO

(H2 + CO) 0.18 H2/

Table 2. Gas composition and heating rate scenario of non-isothermal reduction.

序号 1 2 3 4 5 6

温度ºC ，升温速率 K/min. RT-200ºC, 10 K/min. 200–400ºC, 10 K/min 400–900ºC, 10 K/min. 900–1 000ºC, 2 K/min. 1 000–1 200ºC, 5 K/min. 1 200ºC, 0 K/min for 60 min.

例1 CO–H2–CO2–N2 Vo l .%

0-0-0-100 22-0-23-55 27-3-15-55 30-5-10-55 37-8-0-55 37-8-0-55

例2 CO–H2–CO2–N2 Vo l .%

0-0-0-100 30-12-23-35 35-15-15-35 40-15-10-35 45-20-0-35 45-20-0-35

例3 CO–H2–CO2–N2 Vo l .%

0-0-0-100 40-27-23-10 45-30-15-10 50-30-10-10 55-35-0-10 55-35-0-10

Table 3. Chemical analysis of iron ore sinter.

元素 质量百分数

Fe 57.0

FeO 5.09

Mn 0.47

SiO2 4.722

Al2O3 1.134

CaO 11.5

MgO 0.99

P 0.041

S 0.018

CaO/SiO2 2.43

Table 4. Porosity and density of applied sinter.应用烧结的孔隙度和密度。 测量项目 价值 体积密度g/mL 4.1158 表观密度g/mL 4.5802 总孔隙度g/mL 10.14 The iron ore sinter was examined before and after reduction by reflected light microscope (RLM- Leica Aristomet) and scanning electron microscope-backscattered electron image (SEM-EDX/BSE, ZEISS DSM 962).

铁矿石烧结前检查和烧结还原后通过反射光显微镜(RLM- Leica Aristomet)和电子显微镜扫描，背散射电子图像(SEM-EDX/BSE, ZEISS DSM 962).

The porosity of sinter was measured by poresizer (Micrometrics 9320).

烧结体的孔隙度是由压泵仪（Micrometrics poresizer 9320）进行测定。

The formed phases and its quantitative analysis were identified by high performance X-ray diffractometers (Cu-Kα1 radiation).

形成相和其定量分析是由高性能的X-射线衍射仪确定(Cu-Kα1 radiation).

3. Results and Discussion 3. 结果与讨论

3.1. Characterization of Raw Materials 3.1. 原材料的特性

The chemical analysis of iron ore sinter is given in Table3. The X-ray diffraction analysis of the applied sinter exhibited that the sinter was composed of three main phases:hematite, calcium silicate, and calcium ferrites as given in Fig. 2.

铁矿石烧结矿化学分析给出在表3。所施加的烧结表明烧结是由三个主要阶段的X-射线衍射分析：赤铁矿，硅酸钙，钙和铁氧体 如图2。

铁矿石烧结的化学分析示于表3。所施加的烧结体的X-射线衍射分析显示出了烧结由三个主要阶段：赤铁矿，硅酸钙，钙和铁酸盐作为图给出。 2。

The microstructure of sinter sample was examined by RLM as given in Figs. 3(a)–3(d). 对烧结样品的显微组织进行了检查，RLM为给定的图。3(a)–3(d). The phases were analysed by SEM-EDX. 该阶段通过SEM-EDX分析。

Figure 3(a) showed dense structure of sinter with random distribution of pores. 图3（a）显示，烧结矿致密结构的孔隙随机分布。

Figure 3(b) showed pale white dense grains (m) at the outer surface which is magnetite. 图3（b）显示的是磁铁矿外表面的淡白色致密颗粒（M）。

Figure 3(c) exhibited hematite phase (h) and the presence of calcium ferrite phase (CF) appeared as flakes between and on the outer surface of hematite.

图3（c）表现出的赤铁矿相（H）和铁酸钙相（CF）呈薄片状，存在赤铁矿的外表面。

Figure 3(d) illustrated the presence of calcium silicate phase (CS) distributed between calcium ferrites。 图3（d）说明了铁酸钙中硅酸盐相（CS）的分布。

The total porosity of sinter in addition to the bulk and apparent density were measured by poresizer as given in Table 4 while the pore size distribution is shown in Fig. 4.

用poresizer如表4给出而孔径分布曲线如图4所示是除了体积和表观密度的烧结矿的总孔隙度。

烧结体的除了体积和表观密度的总孔隙度是由poresizer测定，如表4中给出，而细孔径分布示于图。 4。 烧结除了大部分的总孔隙度和表观密度是衡量poresizer如表4中给出而poresize分布是图4所示。

It can be seen two different modes of pores in sinter; small pores which have diameter in range of 0.1–1.0 μm and large pores in the range of 10–100 μm。

可以看出两种不同模式的毛孔在烧结;小毛孔的直径在0.1 - -1.0范围μm和大孔范围内的10 - 100μm。 可以看出两种不同孔隙模式中烧结;小孔具有直径在0.1-1.0微米和大孔隙在10-100微米的范围内的范围。 可以看到两种不同的孔隙中烧结方式；孔隙小，在0.1–1μM和大孔隙10–100米范围内μ直径范 可以看到两种不同的孔隙中烧结方式；孔隙小，在0.1–1μM和大孔隙10–100米范围内μ直径范围 3.2. Isothermal Reduction of Sinter

Typical reduction curves of sinter isothermally reduced by different gas mixtures at 900–1 200ºC are given in Figs.5(a)–5(c) for case 1–3 respectively

典型曲线,减少烧结等温地减少不同气体混合物在900 - 1 200ºC给出Figs.5(a)5(C)1 - 3分别

烧结等降低由不同的气体混合物在900–1 200ºC典型减少曲线在图中给出。5（一）–5（C）为1–分别为3

可以看到两种不同的孔隙中烧结方式；孔隙小，在0.1–1μM和大孔隙10–100米范围内μ直径范围 烧结矿是典型的下降曲线由不同的气体混合物在900〜200℃等温降低（一）-5（c）就个案1-3分别给出了图5，图

The reduction degree was calculated based on the oxygen of iron oxides in sinter.21) 基于铁的氧化物在烧结中的氧的还原度计算

In all cases the reduction degree increased with temperature. 在所有情况下的还原度随温度。

In each case the reduction rate started relatively fast at the initial stages and then converted to stable manner at different time according to the applied temperature till the end of reduction.

在每一种情况下，还原速度开始较快在初始阶段，然后转换为稳定的方式在不同的时间根据实际温度直到结束时减少。

在每种情况下，压下率开始相对快速的初始阶段，然后转换为稳定的方式在不同的时间，根据所施加的温度，直到还原的结束。

In case 1, the reduction reached a maximum value of 54% at 1 200ºC after 150 min while the lowest reduction value of 38% is obtained at 900ºC.

在案例1中，减少达到最高值54% 1 200ºC 150分钟后，最低38%的减少值在900ºC.获得

在案例1中，而在900ºC。得到的38％的最低值减少的减少达到了54％，至1200℃后150分钟的最大价值

The difference between reduction curves decreased with rising temperature and became unremarkable at 1 100 and 1 200ºC while this difference increased in going from case 2 to 3.

还原曲线之间的差异随温度升高而减少，在1 100和1 200ºC成为不起眼而从2到3的情况下这种差异的增加。

减少曲线间的差异变随温度的升高，并在1100和1200℃变得不值一提，而这种差异在持续的情况下2〜3增加。

The reduction degree increased in case 2 and 3 to become 1.5 (83%R) and 1.83 (99%R) times higher than that in case 1 at 1 200ºC;respectively.

在个案2和3的还原度提高到成为1.5（83％R）和比在案例1高1.83（99％R）倍在1200℃;分别。

The comparison between the reduction curves for case 1–3 at the same temperature is given in Figs. 6(a)–6(d). 为1-3的情况下在相同温度下的还原曲线之间的比较，列于图图6（a）-6（d）所示。

At all temperatures, the reduction showed the maxi-mum value in case 3 and the minimum value in case 1. 在所有温度下，还原反应在例3显示出最大值和例1中的最小值。

The reduction degree in case 3 is in range of 1.8–1.9 times higher than that in case 1 as the difference of reduction reached to 35–45%.

案例3中的还原度在1.8–高1.9倍的范围比例1为减少达35–45%的差异。

This difference decreased between case 3 and 2 to become in the range of 7–16% which represented 1.1–1.2 times higher in case 3 compared to case 2.

这种差异减少例3和例2之间，例3中成为7–16%代表1.1–1.2倍相比案例2案范围。

In general, the higher COG injection was resulted in higher potential of reducing gas (CO + H2) and consequently higher reduction rate of sinter.

在一般情况下，较高的COG注射导致还原气（CO + H 2），因此烧结体的高还原率的高电位。 在一般情况下，较高的焦炉煤气注射导致较高的还原气势（CO + H2）和烧结矿的还原率也高。 3.3. Reduction Kinetic and Mechanism 还原反应动力学和机理

In order to clarify the positive effect of COG injection on the sinter reducibility, the reduction rate (dr/dt) at the initial stages (15%) and at moderate (45%) stages of reduction was calculated and plotted against the corresponding temperature, as indicated in Figs. 7(a) and 7(b) respectively.

为了阐明COG注射液对烧结矿的还原性的积极作用 在初始阶段（15％），并在减少的中等（45％）阶段的缩小率（DR/ DT）的计算和绘制在相应的温度，如图所示。7（与图7（b）分别。

It can be observed that, at both the initial (15%) and moderate (45%) reduction stages, the reduction rate increased gradually with temperature for case 2 and 3 while its slowly increased at temperature ≥1 100ºC in case 1.

可以观察到，同时在最初的（15％）和中等（45％）还原阶段，例2和3的还原率随温度增加而逐渐增加，同时例1在温度≥1100℃时它慢慢增加。

In addition, the difference between the rate of reduction in case 2 and 3 increased with temperature at both the initial and moderate reduction stages.

此外，例2和例3的还原反应速率增加的差异表现在温度的初始和适度减少阶段， 。

The rate controlling mechanism at different reduction stages can be predicted from the apparent activation energy calculation and microstructure investigations.

不同还原阶段的速率控制机制可以从表观活化能的计算和微观结构的研究加以预测。 速率控制机制在不同阶段减少可以从表观活化能计算和显微组织的调查进行预测。

The values of apparent activation energy were calculated from Arrhenius equation which is given in Eq. (1). 表观活化能的值可从阿伦尼乌斯方程给出的公式计算。

−

K r = Koe Ea/RT

where,

–

Kr: reduction rate constant (s1),还原速率常数

–

Ko: frequency factor (s1),频率因子

–

Ea: apparent activation energy (kJ. mole1),表观活化能

––

R: universal gas constant通用气体常数 (8.314*103 kJ mole–1K1), and T: absolute temperature 绝对温度(K)

The relationship between the logarithm of reduction rate and the reciprocal of absolute temperature at 15% and 45% reduction is given in Figs. 8(a) and 8(b) respectively.

15%和45%还原的还原速率的对数和绝对温度的倒数关系分别如图8(a) 和8(b)。

还原率和在15%和45%减少绝对温度的倒数的对数之间的关系是给定的图。8（a）和（b）分别为8。 的减少率的对数与绝对温度的15％的倒数和减少45％之间的关系示于图。图8（a）和8（b）分别。 The computed values of apparent activation energy from Arrhenius equation are given in Table 5. 从阿伦尼乌斯方程得到的表观活化能计算值在表5中给出。

The relationship between the activation energy values and the rate controlling step is given in Table 6.22)

）

活化能值和速率控制的步骤关系如表6中所给出的。22

These values indicated that at the initial stages (15%) the reduction is most likely controlled by a combined effect of gaseous diffusion and interfacial chemical reaction with more participation of chemical reaction in case 1. 这些值表明，在初始阶段（15%）的减少是通过综合作用的气体扩散和界面化学反应与更多的参与的情况下，1的化学反应最有可能控制。

这些值表明，在初始阶段（15％）的减少很可能是由气体扩散和界面化学反应的综合效应控制在1的情况下化学反应的更多的参与。

这些数值表明 初始阶段(15%) 的还原反应是最有可能控制 由一个气体扩散的综合效应和界面化学反应 更多化学反应的参与 例1

As the reduction proceeds (45%) the reduction mechanism is still combined effect of gaseous reduction and interfacial chemical reaction with more participation of gaseous diffusion in cases 2 and 3 as the activation energy values deceased.

在反应过程(45%) 还原机理 结合 气体还原的组合效应和界面化学反应 更多的参与气体扩散 例2和例3 活化能

The microstructure examination of sinter reduced up to 45% with different gas mixtures was used to clarify the reduction mechanism suggested by apparent activation energy calculations as shown in Fig. 9.

烧结矿的显微组织 降低至45% 不同的气体混合物 用于 澄清/弄清楚 还原机制的建议 通过表观活化能的计算 表9中给出的

It can be seen that the outer layer consist mainly of metallic iron with some grains of wüstite which decreased in going from case 1 to case 3.

可以看出外层主要由金属铁的维氏体晶粒,从降低例1到例3。

On the other hand the middle layer and core of samples were consisted mainly of iron oxides with the presence of few grains of metallic iron which increased from case 1 to case 3.

另一方面，中间层和核心样品主要由铁的氧化物与金属铁晶粒的增加从1到3的存在。

The presence of wüstite with metallic iron in relatively porous structure in case 1 indicated that the reduction mechanism was mainly chemical reaction while the disappearance of metallic iron in the core of sample indicated the participation of gaseous diffusion mechanism in the rate controlling step.

维氏体与金属铁在相对的多孔结构在壳体1的存在表明，减速机构，主要是化学反应，同时在样品的芯金属铁的消失指示的气体扩散机制中的速率控制步骤中的参与。 Wüstite在案例1中相对多孔结构的金属铁的存在表明，还原机理主要是化学反应而在金属铁样品的核心的消失表明气体扩散机制的速率控制步骤的参与。

维氏体在例1中相对多孔结构的金属铁中的存在表明，反应的还原机理主要是化学反应而金属铁试样的核心的消失表明在速率控制步骤参与反应的气体的扩散机理。

In case 2 and 3, the wüstite grains in outer layer were few which give the chance for the reducing gas to diffuse into the middle and core layer.

在例2和例3，维氏体外层颗粒很少给了中间层和核心层还原气体扩散的机会。 As the diffusion of reducing gas takes place the resistance increased especially for CO. 还原性气体的扩散发生的阻力增大尤其是对于CO。

the diffusivity of reducing gas molecule is inversely proportional to the square root of its molecular weight.23) 还原气体分子的扩散系数与其分子量的平方根成反比。23)

The diffusivity of H2/H2O is 3–5 times faster than that of CO/CO2 depending on the applied temperature.24) H2/H2O中的扩散系数取决于施加的温度，比CO/CO2快3-5倍。24)

The disappearance of metallic iron grains in the core of sinter samples in case 1 and its increasing ingoing from case 2 to case 3 indicated that the diffusivity of reducing gas mixtures increased as the H2/CO ratio increased as given in Table 1.

烧结样品核心金属铁颗粒例1和例3中的消失和例2和例3中持续增加表明混合还原气体的还原系数随H2/CO比值增加而增加

The effect of temperature and gas composition on the micro-structure of sinter reduced at 900 and 1 200ºC for 150 min is shown in Figs. 10 and 11 respectively.

在900和1 200ºC， 150分钟后温度和气体成分对烧结还原矿微观结构的影响分别如图10和11所示。 Figure 10 showed few grains of metallic iron in the outer layer in case 1 and it is completely disappeared in the core of sample.

图10显示例1外层中存在的少数的金属铁颗粒并且在样品的核心中完全消失。

On the other hand more metallic iron grains appeared in the outer layer of case 2 and 3 in a relatively pores structure.

另一方面，例2和例3的外层相对孔道结构中出现更多的金属铁粒。

In the middle layer the metallic iron were segregated as the structure became dense while its appearance decreased in the core.

在中间层中的金属铁 被隔离 作为结构变得致密当它的出现减少 核心中

Figure 11 showed the effect of higher temperature (1 200ºC) on the structure of metallic iron. 图11表明高温 (1 200ºC)对金属铁结构的影响。

The metallic iron grains became denser and larger compared to that at 900ºC. 与900℃时相比金属铁颗粒变得大而致密的。

The iron oxides in the form of hematite and wüstite were only appeared in case 1 and case 2 respectively. 铁氧化物只是在例1和例2分别以赤铁矿和方铁矿的形式出现。

3.4. Non-isothermal Reduction of Sinter 非等温还原烧结矿

The non-isothermal reduction curves of sinter reduced under different conditions of temperature and reducing atmosphere are given in Figs. 12(a)–12(c).

不同温度条件和还原气氛条件下非等温还原烧结矿还原曲线在图12(a)–12(c)给出. The reduction conditions were given in Table 2. 还原条件在表2中给出。

It can be noticed that there was no reduction took place at temperature lower than 600ºC (up to 60 min) in all cases regardless the composition of the applied gas mixtures.

可以看到，无论所施加的混合气体的组分是什么，在三种条件下发生的还原在低于600ºC下（反应60分钟以上）。

After that (starting from 60 min), the reduction was sharply increased with different rate depending on the reduction potential of applied gas mixtures in each case.

在这之后（从60分钟开始）时，还原反应急剧以不同速率增加是由每个例子中施加的混合气体的还原电位决定的。

This remarkable increase of reduction took place as hematite is reduced to magnetite and magnetite to wüstite up to temperature of about 850ºC.

At 850–1 000ºC, the reducing speed shortened as the reduction of wüstite to metallic iron took place. 在850–1 000ºC，方铁矿还原为金属铁时还原速度缩短。

At 1 000–1 200ºC, the changing of the gas mixtures in each case to higher reduction potential through stopping the flow of CO2 in addition to the continuous increasing of temperature resulted in higher reduction rate with different extent.

1 000–1 200ºC，在每一种情况下通过停止二氧化碳的喷入，混合气体的变化获得较高的还原电位，除此之外对温度的不断提高导致不同程度的还原速率增大。

The comparison between the reduction degree for case 1, 2, and 3 is given in Fig. 13. 对于例1，2，和3中的还原程度之间的比较示于图13。

It indicates that the reduction of sinter in case 1 (simulate normal blast furnace conditions) exhibited the smallest reduction degree which reached to only ~50% after 240 min.

它表明例1（模拟正常高炉炉况）中烧结矿的最小还原度其中240分钟后达到只有〜50％。

On the other hand the reduction degree in case 2 and 3 (simulate the conditions of 150 and 300 m3/tHM injection of COG)was reached to 75% and 95% respectively. 另一方面，在例2和3（模拟条件150和300立方米/ 吨铁水注射焦炉煤气）的还原度分别达到75%和95%。

The microstructure photomicrographs of reduced sinter are given in Fig.14. 还原烧结的显微照片图14给出。

The matrix structure consisted of metallic iron and lower oxides in case 1 and 2. 例1和例2的基体组织包括金属铁和较低的氧化物。

In case 3 the iron oxides completely disappeared even at the core of the sample and the metallic iron became predominate all over the matrix.

在例3中，铁的氧化物完全消失，即使在样本的核心，金属铁在所有基质中成为占主导地位。

The qualitative and quantitative analysis of the phases developed in the sinter non-isothermally under different gas

conditions has been carried out using high performance X-ray diffractometers as given in Fig. 15 and Table 7 respectively.

对不同气体条件下的非等温烧结的发展阶段的定性和定量分析已经采用了高性能的X射线衍射仪分别在如图15和表7中给出。

It can be seen that the metallic iron is greatly increased from 16 wt.% in case 1 to more than 79 wt.% in case 3 on account on the reduction of wüstite which decreased from 75.4 wt.% to only 2 wt.%. 可以看出，该金属离子在例1中从16wt.%大大增加甚至超过例3中的79wt.% 帐户上

方铁矿的还原从75.4wt.% 减少到只有2wt.% 。

These finding indicated that the reduction under conditions simulated the injection of 150 m3/tHM (case 2) and 300 m3/tHM (case 3) of COG was very effective in the enhancement of the reduction rate of sinter.

这些发现表明，模拟的还原条件下的150立方米/ 吨铁水（例2）和300立方米/ 吨铁水（例3）的焦炉煤气喷射对烧结矿还原率的提高非常有效。

The improving of the reduction degree of sinter especially at temperature lower than 1 100ºC is very effective factor in decreasing the coke consumption in the blast furnace.25–27)

提高烧结矿的还原度，是高炉中降低焦炭消耗非常有效的因素尤其是在温度低于1100ºC时。

The coke consumption is related strongly to the direct reduction of wüstite which takes place at temperature of about 1 100ºC as given in Eqs. (2)–(4).

焦炭的消耗与方铁矿在1100ºC发生的的直接还原密切相关如公式(2)–(4)。 As the direct reduction decreases with COG injection, the coke consumption decreases. 焦炉煤气喷射下直接还原降低，焦炭消耗降低。

The results of non-isothermal reduction given in Fig. 13 indicates that the reduction degree at 1100ºC in case 3 (~55%R) was 1.7 times higher than that in case 1 (35%R) and this value was increased to 1.9 at 1 200ºC.

图13中给出非等温还原的结果表明例3在1100ºC时的还原度（〜55％R）是例1的（35％R）的1.7倍，1200℃时这个值增加到1.9。

This proves that the direct reduction will decrease by 90% at temperature > 1 200ºC in case 3 compared to that in case 1.

例3与例1相比，说明在温度> 1 200ºC时直接还原将减少90%。

Based on this estimation, only 5% direct reduction will take place at temperature higher than 1 200ºC in case 3 compared to 50% in case 1.

在此基础上估计,相比例1 的50%，例3只有5%的直接还原将在温度高于1200ºC时发生。

公式 若干

The increasing of the difference between the reduction curves as the time proceeded (steps 5 and 6) can be attributed not only to the higher reducing power of applied gas mixtures but also to the higher efficiency of H2 as the temperature increased.

随着步骤5和步骤6的进行，还原曲线之间的差值增加的原因不仅是因为喷射混合气体的高还能力还有H2的效率随着温度的升高而提高。

From the thermal point, the reduction efficiency of H2 becomes higher than that of CO at > 810ºC due to the

endothermic reaction as given in Eq. (5).

从热力学的角度，由于吸热反应公式（5）温度大于810ºC时H2还原效率高于CO。

Although the reduction of wustite with H2 is accompanied by heat absorption but this amount of heat is accounted for only 18% of that consumed in the direct reduction given in Eq. (4).

虽然方铁矿和H2的还原伴随着吸热但是吸收的热量仅占直接还原消耗热量的18%公式(4)。

FeO+ H2=Fe +H2O ΔH°=+28.01 kJ/ mol ..... (5)

This finding clarifies well the enhancement of the reduction process of sinter under conditions simulate the COG injection into the blast furnace.

这一发现解释了模拟高炉喷射高炉煤气条件下，烧结矿还原过程的提高。

The vital role of COG injection is expected to participate in decreasing the direct reduction and consequently the coke consumption in blast furnace.

预计喷射的焦炉煤气对减少直接还原反应有重要作用，因而减少高炉中焦炭的消耗。

However the effect of hydrogen concentration in the gas mixtures on the water gas shift reaction and consequently the coke consumption will be studied in our next investigations.

鉴于混合气体中氢的浓度影响着水煤气变换反应，因此，焦炭消耗将是我们的下一个研究课题。 4. Conclusions 总结

In this study, the reduction behaviour of sinter was carried out under conditions simulated blast furnace operation with different injection level of COG.

在这项研究中，我们模拟了烧结矿在高炉喷吹不同焦炉煤气条件下的还原行为。

The reduction condition was simulated the typical blast furnace conditions (case 1),injection of 150 m3/tHM COG (case 2), and injection of 300m3/tHM (case 3). 模拟的还原条件分别是典型高炉炉况（例1）、喷吹焦炉煤气150立方米/吨铁水（例2）和300立方米/ 吨铁水（例3）。

The isothermal reduction was carried out at 900–1200ºC while the non-isothermal reduction took place from room temperature up to 1 200ºC.

等温反应在900〜1200ºC进行，而非等温反应是室温到1200℃。 The main finding can be summarised as follows: 主要结果可归纳如下：

(1) The isothermal reduction was greatly enhanced in case 3 and case 2 compared to that in case 1. 相比例1，等温还原在例3和例2中得到了大大提高。

The reduction degree increased in case 2 and 3 to become 1.5 and 1.83 times higher than that in case 1 at 1 200ºC; respectively.

1200ºC时，例2和例3的还原度分别增大例1的1.5和1.83倍。

The difference in reduction degree in case 2 and 3 is in the range of 7–16% while it is increased between case 1 and 2 to reach to 35–45%.

例2和例3之间还原度的差异在7–16%而例1和例2达到35–45%。

(2) A correlation between apparent activation energy and microstructure examination of reduced sinter were carried out to elucidate the reduction mechanism:

表观活化能和还原烧结体显微组织检验之间关系阐明还原机理：

at the initial stages (15% reduction) the reduction is most likely controlled by a combined effect of gaseous

diffusion and interfacial chemical reaction with more participation of chemical reaction in case 1.

例1，在初始阶段（15%还原）的还原最有可能是气体扩散和更多化学反应参与的界面化学反应综合作用控制的。

At moderate reduction stages (45% reduction), the reduction mechanism is still combined effect of gaseous reduction and interfacial chemical reaction with more participation of gaseous diffusion in cases 2 and 3.

例2和例3，中等还原阶段（45％还原）还原机理仍然是由气体还原和更多气体扩散参与下的界面化学反应综合影响的。

(3) The non-isothermal reduction exhibited the smallest value (~50% reduction) in case 1 while it increased to 75% and 95% in case 2 and 3 respectively.

非等温还原在例1表现为最小的值（〜50％还原）而在例2和例3分别增至75％和95％。

This indicates that only 5% direct reduction will take place at temperature higher than 1200 ºC in case 3 compared to 50% in case1.

这表明，相比例1的50%，高于1200ºC时例3只有5%的直接还原发生。

(4) The isothermal and non-isothermal results exhibited the efficiency of COG injection into the blast furnace in the enhancement of the reduction process and consequently the decreasing of coke consumption and CO2 emissions.

等温和非等温的结果表明高炉还原过程中喷吹焦炉煤气的效率，从而，减少焦炭的消耗和二氧化碳的排放。 Acknowledgements 致谢

The authors wish to thank for his cooperation and participation in the experiments of the current work. 作者要感谢Mr. J. S. Rathore对当前实验工作的合作和参与。

The authors gratefully acknowledge the financial support provided to the corresponding author of this research by Alexander von Humboldt Foundation in Germany.

作者感谢德国亚历山大•冯•洪堡基金会对通讯作者研究项目提供的资金支持。

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