链篦机—回转窑直接还原的适宜焙烧温度

在实验室进行了链篦机－回转窑直接还原的试验研究。结果表明：还原产品的铁收率得与入窑球团的抗压强度、抗磨能力正相关关系;球团抗压强度及抗磨能力取决于链篦机的焙烧温度。提高链篦机焙烧温度是提高链篦机－回转窑直接还原法铁假得率和杜绝结的重要途径。     

马钢链箅机-回转窑氧化球团试验研究

基于马钢球团原料条件,在模拟试验装置中研究了链箅机-回转窑氧化球团生产的料层高度、鼓风干燥热风温度、抽风干燥热风温度、预热热风温度和回转窑焙烧等工艺参数。在配用40%(质量分数)赤铁精矿时,采用最佳链箅机-回转窑工艺参数条件下,获得了冶金性能良好的成品球团矿,主要指标为:单球抗压强度3 113 N,转鼓强度93.16%,抗磨指数2.00%,w(TFe)63.64%,w(FeO)1.62%。     

有关我国链箅机-回转窑球团对标挖潜指标的探讨

1国内外链箅机-回转窑球团技术发展状况 1．1国外链箅机-回转窑球团技术发展情况 1960年世界上第一套生产铁精矿球团的链箅机-回转窑生产线于美国亨博尔特球团厂建成投产，链箅机宽2．84m，长21．64m；回转窑直径3．05m，长36．6m，单机产量33万t／a。国外链算机-回转窑球团生产系统经过几十年的发展，通过对链一回球团厂焙烧过程的气体系统进行数代的改进，采用完美的焙烧模型控制整个球团焙烧工艺过程。到     

球团强度对回转窑内铁收得率的影响

在实验室Х８００ｍｍ回转窑火力模型上进行了球团强度对直接还原回转窑产品铁收得率影响的试验研究。研究结果表明：球团强度对回转窑内铁的收得率有重大影响，入窑前球团的抗压强度和转鼓强度（耐磨强度）是影响回转窑铁收得率的主要因素。     

链箅机-回转窑系统中的氧化球团冷却

1链箅机-回转窑系统概述 铁矿球团目前在世界范围内已被广泛采用，氧化球团矿早已成为高炉炉料的重要组成部分。铁矿球团经过几十年的发展至今形成了三种主要的球团工艺方法，即竖炉球团法、链箅机-回转窑球团法、带式焙烧机球团法。其中竖炉球团法除在中国外已逐渐走向衰落，其产量在整个球团矿产量中所占的比例已经很低，因此目前用于工业生产的主要是链箅机-回转窑球团法和带式焙烧机球团法。根据美国Allis Mineral System（以下简称AMS，现在已并入METSO）公司的统计，采用链箅机-回转窑法生产的球团矿产量占整个铁矿球团产量的百分之五十左右。     

500万t链箅机-回转窑球团工艺及装备

钢铁行业是耗能大户,为实现节能减排,设备的大型化已经成为发展的必然趋势。在湛江500万t链箅机-回转窑球团的设计过程中,避免了以往链箅机-回转窑球团厂遇到的一些实际问题,开发的大型造球机提高了效率、降低了单耗,成功实现大型链箅机头尾双传动,应用先进的焙烧监控技术防止结圈,实现球团添加内配煤技术,膨润土拆袋全自动技术,以及耐火材料烘烤等先进技术,为推动大型链箅机-回转窑球团工艺的发展迈出了重要的一步。     

生球爆裂温度的影响因素及提高途径

通常用在1．0～2．0m／s气流速度下，10％生球有裂纹或爆裂时的温度作为生球的爆裂温度。爆裂温度是评价生球质量的一个重要指标，它对球团生产尤其是竖炉球团生产至关重要。目前，生产球团矿有3种形式：竖炉、带式焙烧机、链箅机-回转窑。对于带式焙烧机与链箅机一回转窑，可以根据生球的热敏感性选择合适的干燥工艺，而对于竖炉来说，干燥介质温度、     

煤粉对铝土矿球团性能的改善

利用铁矿球团链箅机-回转窑工艺对热量高效利用的特点,需要对铝土矿进行造球,使之能够更好地适用于链箅机。在实验室焙烧设备中进行焙烧试验。试验结果表明:铝土矿球团的水分含量较高,物料粒度过细,在干燥预热过程中易破裂;在配料中加入适量的煤粉可以改善球团质量。     

对球团竖炉技术发展的几点设想

1 前言 国内目前球团矿生产的主要工艺方法有带式焙烧法、链箅机-回转窑法、竖炉法三种。以前由于带式焙烧机和链箅机-回转窑建设投资和制造要求相对较高，一般都适宜于生产规模较大的钢铁企业或矿山，而对于生产规模适中的中小型企业来讲，则采用竖炉法生产球团矿。但目前随着竖炉大型化技术的突破，竖炉法球团生产仍将会占有一席之地。     

链箅机-回转窑工艺生产碱性球团矿工业试验

摘要：在实验室研究的基础上,开展了链箅机-回转窑工艺生产碱性球团矿工业试验。结果表明,生产二元碱度（CaO/SiO2）为1.0左右的球团矿时,与酸性球团矿生产工艺相比,将预热段温度提高30℃左右,回转窑窑头温度降低10℃左右,链箅机的机速降低0.3m/min左右,成品球团矿的抗压强度可达到或稍高于酸性球团矿。碱性球团的还原膨胀率受球团矿抗压强度以及碱度影响较大,当球团矿抗压强度相当于（或大于）酸性球团矿,且碱度大于1.0时,其还原膨胀率才能低于或接近酸性球团矿。     

Effects of the Composition of Residual Materials from Steelwork on the Crushing Strength of DRI

The goal of this study is to investigate the effects of the composition of residual materials, such as the basicity and (C/O_red)_mol, as well as the reduction temperature and time, on the crushing strength of direct reduced iron (DRI) under the carbothermic reduction through the rotary hearth furnace (RHF) process. Laboratory‐ scale experiments were executed to examine the DRI quality in the RHF operation. It is observed that when the composition of residual materials varies or the reduction temperature and time decrease, DRI crushing strength becomes lower than the 60 kg/piece requirement for blast furnace feed stock. Both basicity and (C/O_red)_mol of the residual materials would affect the crushing strength of DRI. As B₂ increase, the crushing strength of DRI also rises, and the maximum value is when the basicity is 1.4. The result shows that as the value of (C/O_red)_mol rose above 1.20, the DRI strength declined.     

回转窑一步法直接还原铁生产的试验研究

以新疆磁铁精矿为原料,采用一步法直接还原,研究高强度、高还原性预热球团的制备及煤基直接还原的工艺.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化率、脱硫率等回转窑直接还原铁的主要质量指标的影响,提出了本试验原料条件下,回转窑生产直接还原铁的最佳工艺参数.研究结果...     

球团矿氧化焙烧及还原过程中的强度变化

研究了球团矿在氧化焙烧和还原过程中抗压强度的变化规律.通过焙烧试验得到了球团矿必要的焙烧温度.通过还原反应后的高温抗压强度研究估算了球团矿焙烧中必要的强度.使用可调气氛高温抗压试验机研究了相应球团矿在氧化焙烧过程中的强度变化规律.球团矿在焙烧过程中有一个强度大幅下降的特定温度.如果该温度高于必要的焙烧温度,焙烧工艺是可行的.     

Influence of Direct Reduction Condition of Hematite Pellets with H2/CO on the Oxidation Behaviour of DRI in Air

Direct reduced iron (DRI) is the product of some commercial direct reduction (DR) of iron ore on base of natural gas. DRI tends to oxidize in air generally above 300 °C and then follows spontaneous combustion. To control the oxidation mechanism, several investigators have used different iron samples and methods. This paper gives the results of experimental work carried out for determination of DRI oxidation. The behaviour of DRI oxidation in air after isothermal reduction of hematite pellets with different size, temperature and H₂ / CO mixture is investigated.     

Study on Direct Reduction Characteristics of Iron Ore Coal Mixed Pellets

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Effects of Temperature and Atmosphere on Pellets Reduction Swelling Index

 After taking into account the conditions of the domestic iron resources and the non-coking coal resources, the process of coal gasification-shaft furnace is an effective way to develop direct reduction iron in China. The following tasks are very critical to choose suitable process of shaft furnace and gasification, including the production of oxidized pellets with excellent comprehensive properties as well as the study of the reaction behavior and mechanism of swelling. The results showed that the oxidized pellets of using domestic magnetic iron concentrate as raw materials have favorable comprehensive properties, including higher mechanical strength both before and after reduction, faster reduction rate and lower reduction swelling index (RSI). All of these properties can meet the shaft furnace yielding requirement. When the temperature was below 1223 K, the pellets′ RSI was lower than 20%. With increasing of the content of H2 in atmosphere, the pellets reaction rate accelerated, crushing strength enhanced and RSI decreased. The RSI dropped to 10.26% at 1323 K in 100% H2 atmosphere, and it is up to 39.88% in 100% CO atmosphere. The iron grains mainly presented in platelike when pellets were reduced by H2, however, in CO atmosphere the iron grains were precipitated in flocculent. The whisker shape of iron grains and heating effects of reduction reaction are the major factors leading to the poor pellets strength and increase of RSI. Appropriately controlling the temperature and increasing the ratio of H2 to CO in atmosphere are good for dropping the RSI.     

Role of Heat Transfer in Early Stage Decarburization of DRI in Slag

The gas generation from reactions between direct reduced iron (DRI) pellets and steelmaking slags is known to take place in two stages; (1) the reaction of FeO and carbon within DRI, i.e., pellet internal reaction, followed by (2) the reduction of slag FeO with DRI carbon at the pellet?Cslag interface, if any carbon remains from the first step. To understand the controlling mechanism of the reaction between FeO and C inside DRI, the rate of the gas release and the temperature of pellets suspended in a slag-free atmosphere were quantified. The results were used to determine the apparent thermal conductivity of DRI that showed values of approximately 0.5 to 2 W.m^?1.K^?1 for a temperature range of 573?K to 1273?K (300?°C to 1000?°C). Furthermore, it was found that the experimental gas evolution rates are consistent with the values predicted by a heat?Ctransfer based model, confirming that the FeO-C reaction within pellet is controlled by the rate of heat transfer from the slag to the DRI pellet.     

The Reaction Behavior of Direct Reduced Iron (DRI) in Steelmaking Slags: Effect of DRI Carbon and Preheating Temperature

An experimental study was conducted to quantify the rate of direct reduced iron (DRI) decarburization in a steelmaking slag using the constant volume pressure increase technique. Experiments were conducted by dropping DRI pellets into molten slag at temperatures from 1773 K to 1873 K (1500 °C to 1600 °C). Subsequent experiments were carried out in which the DRI pellets were preheated while the slag temperature remained constant. The effect of the initial carbon content and the preheating temperature of the DRI on the reaction rate was investigated. The decarburization of DRI seems to comprise two stages, a reaction between the FeO and DRI followed by decarburization through the iron oxide of slag. Carbon has a significant effect on the kinetics of both stages, whereas the preheating temperature mainly influences the rate of decarburization between FeO and carbon inside the pellet.     

生物质合成气直接还原铁矿-生物质复合球团炼铁

为了使炼铁工业摆脱对化石能源的依赖及满足越来越严格的环境要求,将生物质能的开发利用与直接还原技术进行集成提出一种新型的绿色炼铁方法.把生物质、铁矿石粉与添加剂混合制取生球团,利用生物质催化气化制备的富氢合成气作为还原剂,生物质的高温燃烧为生球团的预热和预热球团的直接还原提供外加热源.对影响生物质直接还原炼铁的因素,如预热、还原温度及球团粒径进行了研究,发现减小球团粒径、增加预热和还原温度能够提高直接还原铁产品的全铁质量分数及金属化率.当采用品位65.21%的铁精矿为原料,在最优操作条件下(生球团粒径介于8~10 mm之间,900℃预热30 min,1000℃下还原60 min)可制得全铁TFe质量分数为86.1%,金属化率为94.9%的高质量直接还原铁产品.