直接还原铁在我国的发展现状及前景

直接还原铁的化学成分稳定，杂质含量低，是一种优势的炼原料，本文阐述了直接还原铁的发展状，并指出我国直接还直铁的发展具广阔的前景。     

焦炉煤气竖炉法生产直接还原铁的煤气用量探讨

用焦炉煤气生产直接还原铁既可解决气源问题,又可高效利用焦炉煤气.目前我国还没有成熟的焦炉煤气竖炉法生产直接还原铁工艺,本文通过热力学分析,从还原剂和载热体两方面来探讨焦炉煤气竖炉法生产直接还原铁的煤气用量方案.     

煤种对低品位铁矿煤基直接还原的影响

我国发展直接还原铁生产应以煤基直接还原为主，煤基直接还原过程中，煤种对产品指标影响很大，特别是对煤的反应性、灰分和挥发分含量对直接还原的影响较大，煤的质量较好时，由低品位铁矿煤基直接还原生产直接还原铁时，可获得ｗＴＦｅ≥９１％，ηｍ≥９２％ε≥８６％的良好指标。     

峨口矿氧化球团直接还原生产工艺的试验研究

介绍了实验室转鼓模拟回转窑装置中生产直接还原铁的工艺研究 ,讨论了配碳比、反应温度、反应时间等工艺参数对∑Fe、金属球强度等回转窑直接还原铁的主要质量指标的影响 ,提出了本实验原料条件下 ,回转窑生产直接还原铁的最佳工艺参数     

回转窑直接还原铁生产的试验研究

研究了实验室转鼓模拟回转窑装置中直接还原铁的生产工艺，讨论了配碳比，反应温度，反应时间等工艺参数对金属经率，脱硫率等回转窑直接还原铁的主要质量指标的影响，提出了本实验原料条件下，回转窑生产直接还原铁的最佳工艺参数。     

煤气化直接还原新工艺的研究

介绍了几种煤气化直接还原竖炉新工艺的工艺流程及其特点，通过分析对比论证，说明在我国采用富氧或全氧煤气化直接还原竖炉新工艺生产直接还原铁的必要性和可行性。     

非高炉炼铁工艺的发展及评述

介绍了近年来国内外直接还原铁的生产概况,分析了不同非高炉炼铁工艺的状况.通过对几种有代表性的工艺的分析,认为Midrex和HYL-III是最成熟最主要的直接还原炼铁工艺.FASTMET工艺近年来已不断完善,我国应在引进、消化新工艺的基础上,开发适合我国资源条件和国情的具有独立知识产权的新技术.     

反应罐直接还原铁脱硫的研究

对反应罐煤基直接还原铁进行了脱硫实验研究.研究了脱硫剂CaO加入量对海绵铁脱硫率的影响,考察了CaO、CaCO3、白云石等不同脱硫剂的脱硫效果,得到了最高脱硫率时海绵铁中硫的分布情况.     

反应罐直接还原铁精矿的动力学研究

系统地研究了反应罐直接还原铁精矿新工艺的基础理论,为铁精矿直接还原技术的应用提供了理论与实践依据.研究结果表明,海棉铁的金属化率随反应的保温温度和反应时间的增加而增大;碳气化反应的活化能为17.0 kJ/mol,气体扩散为碳气化过程的限制环节.     

钒钛磁铁精矿冷固球团催化还原机理

对添加剂催化钒钛磁铁精矿冷固球直接还原行为进行了详细的研究。包括添加剂种类和用量及催化剂催化还原机理．研究结果表明：在１０５０～１１００℃,ｍ（Ｃ）：ｍ（Ｆｅ）为０．５～０．６,还原时间３ｈ的条件下,添加ＤＡ－２催化剂与常规的Ｎａ２ＳＯ４或Ｎａ２ＣＯ３相比,钒钛磁铁精矿冷固球团煤基直接还原所得产品的金属化率提高３．１％～４．６％;该金属化球团经磨矿磁选进行铁和钒钛分离时,所得磁性产品（直接还原铁粉     

Review of current method to determine outburst threshold limits in Australian underground coal mines

Desorption rate index (DRI) was presented to the Australian underground coal industry in 1995 as a means for determining outburst threshold limits for Australian coal seams. DRI is a measure of the gas volume released from a coal sample in the first 30 s of crushing during the Q3 stage of gas content testing, multiplied by the ratio between measured Q3 and QM. Relationships were identified between QM and DRI for both CO₂ and CH₄ rich coal samples collected from the Bulli Seam at West Cliff Colliery and that identified relationship was referred to as the Bulli Seam Benchmark. The outburst mining gas content threshold limit values specified for the Bulli Seam at that time, when applied to the QM-DRI Bulli Seam benchmark, was shown to closely align with a DRI value of 900 (DRI900), for both CO₂ and CH₄ rich seam gas conditions. The Australian coal industry adopted the DRI900 as the basis for determining outburst gas content TLV for Australian coal seams. Outburst mining experience in Australia has shown that gas content is not the only significant factor that impacts outburst risk, as all significant outburst events have been associated with abnormal geological conditions, such as faults and dykes. Therefore, assessing the potential application of additional outburst risk factors, to accurately define outburst risk zones, set safe mining threshold levels, and determine appropriate mining controls, warrants further investigation. Several Australian coal mines have implemented mining procedures enabling mining to continue in areas with gas content greater than the TLV determined using the DRI900 approach, without inducing an outburst. There is a broad lack of understanding among Australian coal mine operators as to the procedure and calculations used to determine DRI. Also, there has been growing concern regarding the accuracy and validity of the DRI900 method for determining outburst TLV. A comprehensive set of gas data has been collected from Australian coal seams, including the Bulli Seam, and this data has been used to investigate the DRI, Bulli Seam Benchmark, and the applicability of using DRI900 as the basis for assessing outburst risk and determining gas content TLV. The results are presented and discussed.     

Investigations into the identification and control of outburst risk in Australian underground coal mines

Australian coal mines currently use gas content to assess outburst risk. The gas content threshold values for each mine are indirectly determined from measurement of gas volume liberated from 150 g coal samples during Q_3 residual gas content testing. It has been more than twenty years since this method, known as desorption rate index(DRI), was presented to the Australian coal industry, and in that time, there have been significant changes in mining conditions and the outburst threshold limits used at the benchmark Bulli seam mines. NSW Regulations list matters to be considered in developing control measures to manage the risk of gas outburst, and specifies that gas content, or DRI method, is used as the basis for determining outburst control zone. Whilst Queensland Regulations state that a coal or rock outburst is a high potential incident, there is no guidance provided to assist mine operators to define outburst prone conditions. A research project is planned at UOW to investigate the application of the DRI method and other potentially significant factors, such as gas pressure, coal toughness and permeability, which can be utilised by mine operators to assess outburst risk and determine appropriate outburst threshold limits and controls.     

Effect of Na<Subscript>2</Subscript>CO<Subscript>3</Subscript> and CaCO<Subscript>3</Subscript> on coreduction roasting of blast furnace dust and high-phosphorus oolitic hematite

Iron was recovered from blast furnace dust and high-phosphorus oolitic hematite in the presence of Na₂CO₃ and CaCO₃ additives. The functions of Na₂CO₃ and CaCO₃ during the coreduction roasting process were investigated by XRD and SEM-EDS analyses. Results indicate that these additives not only hinder the reduction of fluorapatite, CaCO₃ also decreases the P content of direct reduced iron (DRI) by increasing the reduction alkalinity. P remains as fluorapatite in the slag, which can be removed by grinding and magnetic separation under optimal conditions. The Na₂CO₃ promotes hematite reduction and improves the iron recovery (ε_Fe) by replacing the FeO from fayalite, which results in quick growth and aggregation of metallic iron and improvement of ε_Fe in DRI. A DRI with 91.88 mass% Fe, and 0.065 mass% P can be achieved at a recovery of 87.86 mass% under the optimal condition.     

电炉法生产IF钢的工艺研究

提出了用电炉法生产IF钢的合理工艺配置,阐明了通过采取相应的技术措施如选择合适的炉料配比(增加铁水、DRI或生铁的使用量)、正确的生产操作(如电炉内吹氧喷碳造泡沫渣、钢包内脱氧,注意钢水在连铸过程中的保护浇注等)并配备合适的钢水二次精炼设备如LF+VTD-OB后,可以生产部分IF钢(CQ,DQ和DDQ级)产品.     

提高反应罐直接还原铁反应速率的研究

采用铁精矿粉压型的方法,在实验室条件下,进行了不同温度、时间条件下的反应罐直接还原实验.与铁精矿粉松装状态的实验结果对比,铁精矿粉压型还原时间缩短,还原速度提高,反应活化能值相近,反应的控速环节未变,仍是碳的气化反应控速,分析了铁精矿粉压型后还原速度提高的原因.     

Drillability prediction in some metamorphic rocks using composite penetration rate index(CPRI)——An approach

Assessment of drillability of rocks is vital in the selection, operation, and performance evaluation of cutting tools used in various excavation machinery deployed in mining and tunneling. The commonly used rock drillability prediction methods, namely, drilling rate index(DRI) and Cerchar hardness index(CHI)have limitations in predicting the penetration rate due to differential wear of the cutting tool in rocks with varied hardness and abrasivity. Since cutting tools get blunt differently in different rocks, the stress beneath the tip of the bit decreases until it reaches a threshold value beyond which the penetration rate becomes constant. In this research, a new composite penetration rate index(CPRI) is suggested based on the investigations on four metamorphic rocks viz. quartzite, gneiss, schist and phyllite with varied hardness-abrasivity values. The penetration-time behavior was classified into active, moderate, passive,and dormant phases based on the reduction in penetration rate at different stages of drilling. A comparison of predicted penetration rate values using DRI and CPRI with actual penetration rate values clearly establishes the supremacy of CPRI. Micro-structure and hardness-based index was also developed and correlated with CPRI. The new indices can help predict cutting tool penetration and its consumption more accurately.     

高温煤气可再生脱硫剂与脱硫过程

煤气的高温脱硫净化是IGCC和DRI生产的瓶颈,直接影响整个过程的热效率。采用氧化铝负载氧化锰的锰系脱硫剂,具有良好的850℃高温脱硫再生性能。锰系脱硫剂的活性中心是Mn-Al-O尖晶石物相,在850℃高温下可以进行较完全的体相S/O交换反应,得到较好的硫容。实验证明,锰系脱硫剂中,Mn/Al良好的相互作用是脱硫剂可再生的关键,不管是浸渍法制备的脱硫剂还是共沉淀法制备的脱硫剂都可以得到较高硫容。采用共沉淀方法可以很容易得到更高Mn负载量,当Mn含量为46.4%时,其硫容可达到30 g（S）/100 g（脱硫剂）。脱硫实验表明,脱硫反应是快反应过程,使用SO2作为再生气体,可以将脱硫剂再生反应与Clause反应耦合生成单质S,从而实现S的资源化回收。通过造粒后的脱硫剂的活性测试和机械性能测试,该脱硫剂在850℃高温下无论是化学性质还是机械强度性质都是稳定的。     

A New High Quality EAF Charge

In order to so1ve the problem of the shortage of scrap, especially high quality scrap, granular pig iron, a new substitute for scrap or DRI (direct reduction iron) has been developed. The technical process of decarbonized granular pig iron has been evaluated. The result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity burden equivalent to heavy scrap.