粉尘含碳球团还原方式及气氛对其还原挥发性能的影响

在１１５０℃和１２５０℃，０．１Ｌ／ｍｉｎ和１０Ｌ／ｍｉｎ的气量下，对通入含不同ＣＯ２量的氮气影响粉尘含碳球团还原速度的实验研究表明，以滚动方式所造球团中氧化物的还原完全以间接还原方式进行，气氛中非还原气体流速（或流量）的增加对粉尘含碳球团氧化铁不速度有显著的降低作用，但还原温度提高则气量增加造成的氧化铁还原速度降低有显著和抵消作用，气氛对球团中的挥发速度影响很小，对铅的挥发速度几乎不产生影响。     

碱度对热压含碳球团软熔滴落性能的影响

热压含碳球团是一种利用煤的热塑性提高冶金性能的新型炼铁原料,具有还原速度快、高温强度高、原料适应性强等优点。在固定碳氧比n(FC)/n(O)为1.00的条件下,通过改变热压含碳球团碱度,系统研究了碱度对热压含碳球团软熔滴落性能的影响。研究表明:碱度对软化区间、熔化区间、滴落率等软熔滴落性能参数有显著的影响。随着碱度的增加,软化区间t40-t4先变窄后加宽,在碱度为1.40时最窄,降至331℃;熔化区间tD-tS先缓慢变窄后急剧加宽,在碱度为1.00时最窄,降至47℃;滴落率先增加后降低,在碱度为1.20时滴落率最高,达到22.22%。从软熔滴落性能角度综合考虑,实际生产热压含碳球团时其适宜的碱度范围为1.00~1.20。     

含碳球团还原技术研究现状

分析了含碳球团还原的特点,对含碳球团各种还原工艺进行了比较,提出了含碳球团还原技术的发展方向。     

粘结剂对含碳球团还原的影响

水玻璃已被证明是用于含碳球团的理想粘结剂，作研究了在９００～１２００℃、氮气氛中粘结剂（水玻璃）对含碳球团还原的影响。对实验数据进行了动力学分析，给出了理论解释，并指出了其在生产中的应用。结果表明：水玻璃可促进含碳球团还原。该还原反应由球团内矿粒层中的气相内扩散控制，加入水玻璃并没有改变这一限制环节，但可减少该环节的阻力。     

含碳球团还原反应及其技术

对含碳球团的自还原反应和工艺中涉及的燃烧和氧化反应进行了论述,分析了煤的性质、氧化性气氛对含碳球团自还原性的影响;介绍并且评价了现有和正在研发的含碳球团直接还原法和熔融还原法。     

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。     

含碳球团还原机理研究

在１２２３－１４７３Ｋ的Ｎ２气氛下研究了石墨粉粒度、铁精矿粉粒度、温度、碳含量地含碳球团的速度的影响，结果表明，石墨粉和铁精矿粉粒度越小，还原温度和碳含量越高，含碳才还原速度越大，基于碳气化反应、气相扩散和界面反应和含碳球团的速度方程均能较好地处理本研究的数据，根据Ａｒｒｈｅｎｉｕｓ方程计算出的碳敢化反应和界面反应活化能分别为２２７．７和２９４．１４ｋＪ／ｍｏｌ；计算出的气相扩散为限制环节的含碳球     

热压含碳球团技术发展及其应用前景

介绍了热压含碳球团技术研究进展概况及其生产工艺,详细阐述了JFE对含碳热压球团的研究,并对其应用前景进行了分析。     

高炉炉料配加热压含碳球团软熔滴落性能的试验研究

 以常用的炼铁原料为基础,系统研究了配加不同比例的热压含碳球团对高炉炉料的软熔滴落性能的影响,并进行了理论分析。研究表明,配加热压含碳球团对高炉综合炉料的软化区间、熔化区间、滴落率和透气性等软熔滴落性能参数有显著的影响。随着热压含碳球团配比的增加,软化区间t40-t4逐渐变宽;熔化区间tD-tS逐渐变窄,熔化开始温度tS逐渐升高,滴落温度tD逐渐降低;滴落率先增加后降低,当配比为40%时,滴落率最高,为6710%;最高压差先下降后升高,但在配加热压含碳球团条件下,炉料的最高压差都有所降低。从综合炉料的软熔滴落性能综合考虑,高炉炉料配加热压含碳球团的适宜配比应为40%~50%。     

含碳球团竖炉直接还原试验研究

文中报告了９００～９７０℃下含碳球团竖炉直接还原热模拟试验的结果,试验结果表明：含碳４％～８％冷固结含碳球团的冶金性能,可以满足竖炉直接还原的要求;同时发现在含碳球团竖炉直接还原过程中,仍以气体还原为主,但固体碳直接还原的比例随温度升高而增加。并研究了含碳球团竖炉直接还原的规律和工艺参数。     

Fundamental Study on Carbon Composite Iron Ore Hot Briquette Used as Blast Furnace Burden

Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%–50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi‐fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced.     

高炉使用含碳复合炉料的原理

 高炉炼铁正朝着高产、低污染、低能耗的方向发展,为了实现这一目标,包括高炉使用含碳复合炉料等一些革新的炼铁技术已经被提出或实际应用。铁焦、热压含碳球团是将铁矿粉和煤粉按一定比例混合后制成的新型含碳复合炉料。研究结果指出,含碳复合炉料相比于传统的高炉炉料（烧结矿和球团矿）具有高温强度高、还原性能好以及原料适应性强等优势。阐明了高炉使用含碳复合炉料的基本原理,介绍了铁焦制备的工艺流程及应用情况,重点进行了热压含碳球团制备工艺流程、冷态冶金性能、高温冶金性能、高炉使用热压含碳球团等试验研究,最后利用多流体高炉数学模型对高炉使用热压含碳球团操作进行了模拟研究。研究表明,高炉使用一定量的含碳复合炉料可以降低热空区温度,增加产量,降低焦比,高炉热利用效率明显提高,操作性能得到有效改善。     

基于低温快速预还原的熔融还原炼铁流程

提出了基于低温快速预还原的熔融还原炼铁流程。由三部分组成:熔融气化炉,主要功能是熔化海绵铁和产生预还原所需的还原煤气;预还原部分,由两级快速循环床和一级矿粉预热床组成,主要功能是将矿粉转变成高金属化率的铁粉,金属化率大于85%;煤气处理,包括尾气换热、煤气洗涤、煤气增压、脱除CO2等工序,功能是调节预还原所需的煤气成分、煤气量与温度。新工艺采用精矿粉或粒度小于1 mm的矿粉,具有还原温度低、反应接近平衡态、金属化率高等特点,吨铁燃料比有望在600 kg左右,实现炼铁工艺的高效、节能与减排。     

Direct Reduction of Mixtures of Manganese Ore and Iron Ore

This paper presents recent results of direct reduction investigation of different combination of blends of manganese ore, iron ore and coal at the Department of Ferrous Metallurgy (IEHK) of RWTH Aachen University. A mixture of iron and manganese ore in a ratio of 75/25 is a good raw material for steelmaking of high Mn‐alloyed grades. The experimental studies consisting of reduction of (a) fine material and (b) agglomerated material (briquettes) were carried out in the range of 1273 to 1673 K. The behaviour of combined reduction of manganese ore and iron ore and the employment in the direct reduction on a coal and gas basis for production of steels with high Mn content were investigated. It was found that a high metallization degree for Mn can be reached at 1273 K with the reduction of manganese ore by hydrogen‐containing gas. Addition of carbon monoxide to the reducing gas retarded the reduction process. The addition of coal to manganese ore and iron ore blends increased the degree of reduction. The results of carbothermic reduction of briquettes consisting of a mixture of manganese ore and iron ore combined with coal as reducing agent show that a high temperature, a low Mn/Fe ratio and a high Fe₂O₃ content have a favourable effect on the degree of reduction. In order to obtain a high degree of metallization, the temperature should be higher than 1473 K. The reduction of briquettes at higher temperatures (up 1573 K) has shown a molten phase and the separation of slag and metal.     

Application of carbon composite iron ore hot briquette to innovative ironmaking process

As a new type of ironmaking raw materials,carbon composite iron ore hot briquette(CCB) is the product of fine iron ore and fine coal by hot briquetting process.On basis of experimental research on the manufacturing and metallurgical properties of CCB,this study focused on the application of CCB to blast furnace ironmaking and newly-developed shaft furnace smelting reduction processes.Firstly,the metallurgical properties of CCB are experimentally tested and compared with the common iron-bearing burdens.Th...     

球团矿高温还原过程中抗压强度变化及机理

 运用自行设计制造的固态物料高温抗压强度与蠕变在线测试仪,分别测试球团矿在不同温度及还原度状态下的抗压强度及蠕变量,用以表征球团矿在高炉内不同位置的抗压能力。研究发现：未发生还原反应球团矿在中性气氛中,当温度达到1 000 ℃时,球团矿的抗压强度为2 750 N以上,继续升温,球团矿抗压强度下降迅速;球团矿在还原气氛下,还原初期球团矿抗压强度比同温度下中性气氛球团矿抗压强度有较大下降,当温度高于900 ℃时,球团矿抗压强度只有1 250 N,且在抗压试验中形变明显。微观结构分析表明：还原过程中高价铁氧化物到低价铁氧化物变化过程中晶格增大、新生铁相基体孔隙增加、裂纹产生以及颗粒间固相固结减弱是导致强度下降的主要原因。