Designing for Long Campaign Life Blast Furnace (1)──The Mathematical Model of Temperature Field for Blast Furnace Lining and Cooling Apparatus and New Concept of Long Campaignship Blast Furnace Cooler Design

The physical and mathematical model of temperature field for blast furnace stave coolers was established. The computation results show that the heat resistance of 2-6 mm water scale within the cooling pipe is about 7%-20% of the total heat resistance of cooling stave body, as for drilling duct type, the heat resistance of 2-6 mm water scale is about 88%-98% of the total heat resistance. Using drilling duct or full cast pipe can eliminate gas clearance and coating layer between pipes and cast iron body and reduce the heat resistance of the cooler sharply and improve the coefficient of heat transfer to a great extent. The water velocity within coolers can be kept at the 1evel of 0.5- 1 .5 m/s, the higher water velocity can not decrease the hot surface temperature, but can increase energy consumption for cooling water.

Application of Air-cooled Blast Furnace Slag Aggregates as Replacement of Natural Aggregates in Cement-based Materials：A Study on Water Absorption Property

The influence of air-cooled blast furnace slag aggregates as replacement of natural aggregates on the water absorption of concrete and mortar was studied, and the mechanism was analyzed. The interface between aggregate and matrix in concrete was analyzed by using a micro-hardness tester, a laser confocal microscope and a scanning electron microscope with backscattered electron image mode. The pore structure of mortar matrixes under different curing conditions was investigated by mercury intrusion porosimetry. The results showed that when natural aggregates were replaced with air-cooled blast furnace slag aggregates in mortar or concrete, the content of the capillary pore in the mortar matrix was reduced and the interfacial structure between aggregate and matrix was improved, resulting in the lower water absorption of mortar or concrete. Compared to the concrete made with crushed limestone and natural river sand, the initial absorption coefficient, the secondary absorption coefficient and the water absorption capacity through the surface for 7 d of the concrete made from crushed air-cooled blast furnace slag and air-cooled blast furnace slag sand were reduced by 48.9%, 52.8%, and 46.5%, respectively.

Cooling Water Flow Rate Calculation for Hearth of Large Blast Furnaces

The cooling water flow rate for hearth of large blast furnaces was calculated by simulation. The results show that the cooling water flow rate shall be above 4 200m3/ h for hearth of large blast furnaces; to meet requirements of the increasing smelting intensity and to ensure the safety at the end of the first campaign,the designed maximum cooling water flow rate should be 5 900m3/ h; according to the flow distribution stability and the calculated resistance loss,hearth cooling stave pipes with the specification of 76 mm × 6 mm shall be adopted to assure the flow velocity in pipes of hearth cooling stave in the range of 1. 9- 2. 3 m / s.

The Impact of Marine Water on Different Types of Coarse Aggregate of Geopolymer Concrete

This research studies the impact of different types of coarse aggregate on the behavior of geopolymer concrete based on both fly ash (FA) and ground granulated blast furnace slag (GGBFS) in different marine environments. Aiming to solve the problems caused by the construction and demolition waste and the depletion of natural aggregates, in the present study coarse recycled aggregates is used to produce new green concrete with a fly ash-slag based geopolymer. By this examination, the research seeks to improve the quality and productivity of concrete used in construction and hydraulic projects. For this research, four mixtures containing different types of coarse aggregate in two different water environments were used. The utilized mixtures contained natural aggregate concrete (NAC) such as basalt and crushed marble. Also, recycled coarse aggregate concrete (RAC), which totally replaced natural aggregate, was presented in this paper such as crushed concrete and crushed ceramic. For this study, in the sieve analysis;specific and unit weights, was recorded. Furthermore, the mechanical properties were determined, using a compressive test that was conducted on the 7th, 28th, 56th and 90th days at different water environments;potable water (PW) and sea water (SW). Durability test was also performed for total absorption measurement. Results indicated that geopolymer concrete exhibits better strength in marine environments than in those of potable water. Results also showed that crushed marble (CMA) exhibits higher compressive strength and durability.

Possibility of Sea Water as Mixing Water in Concrete

In the near future, fresh water will be very difficult to get and scarce. It is said that in 2025 half of the mankind will live in the areas where fresh water is not enough. Also, UN and WMO （World Meteorological Organization） are predicting five billion people will be in short of even drinking water. Also, in the present, there are some areas where sea water or chloride contained sand are used as mixing water with or without intension. The authors believe that the possibilities of using sea water as mixing water in concrete should be investigated seriously. In this paper, the authors would like to show various possibilities of using sea water as mixing water in RC （reinforced concrete） members. The possibilities are shown as follows： （1） mixed with pozzolanic materials （Blast furnace slag powder, etc.） expecting to fix the free chloride ion; （2） Mixed with corrosion inhibitor; （3） reinforced with stainless steel or corrosion resistant reinforcement; and （4） used in very dry or submerged conditions.

Tests on Alkali-Activated Slag Foamed Concrete with Various Water-Binder Ratios and Substitution Levels of Fly Ash

To provide basic data for the reasonable mixing design of the alkali-activated (AA) foamed concrete as a thermal insulation material for a floor heating system, 9 concrete mixes with a targeted dry density less than 400 kg/m3 were tested. Ground granulated blast-furnace slag (GGBS) as a source material was activated by the following two types of alkali activators: 10% Ca(OH)2 and 4% Mg(NO3)2, and 2.5% Ca(OH)2 and 6.5% Na2SiO3. The main test parameters were water-to-binder (W/B) ratio and the substitution level (RFA) of fly ash (FA) for GGBS. Test results revealed that the dry density of AA GGBS foamed concrete was independent of the W/B ratio an RFA, whereas the compressive strength increased with the decrease in W/B ratio and with the increase in RFA up to 15%, beyond which it decreased. With the increase in the W/B ratio, the amount of macro capillaries and artificial air pores increased, which resulted in the decrease of compressive strength. The magnitude of the environmental loads of the AA GGBS foamed concrete is independent of the W/B ratio and RFA. The largest reduction percentage was found in the photochemical oxidation potential, being more than 99%. The reduction percentage was 87% - 93% for the global warming potential, 81% - 84% for abiotic depletion, 79% - 84% for acidification potential, 77% - 85% for eutrophication potential, and 73% - 83% for human toxicity potential. Ultimately, this study proved that the developed AA GGBS foamed concrete has a considerable promise as a sustainable construction material for nonstructural element.

Synthesis of highly effective absorbents with waste quenching blast furnace slag to remove Methyl Orange from aqueous solution

Water quenching blast furnace slag （WQBFS） is widely produced in the blast furnace iron making process. It is mainly composed of CoO, MgO, A1203, and SiO2 with low contents of other metal elements such as Fe, Mn, Ti, K and No. In this study, WQBFS was treated with grinding, hydrochloric acid acidification, filtration, filtrate extraction by alkali liquor and a hydration reaction. Then BFS micropowder （BFSMP）, BFS acidified solid （BFSAS） and BFS acid-alkali precipitate （BFSAP） were obtained, which were characterized by X-ray diffrac- tion, scanning electron microscopy, X-ray fluorescence and Brunauer-Emmet-Teller （BET） specific surface area. The decoloration efficiency for Methyl Orange （MO） was used to evaluate the adsorptive ability of the three absorbents. The effects of adsorptive reaction conditions （pH and temperature of solution, reaction time, sorbent dosage and initial concentration） on MO removal were also investigated in detail. The results indicated that BFSAP performed better in MO removal than the other two absorbents. When the pH value of MO solutions was in the range 3.0-13.0, the degradation efficiency of a solution with initial MO concentration of 25 mg/L reached 99.97% for a reaction time of 25 rain at 25℃. The maximum adsorption capacity of BFSAP for MO was 167 mg/g. Based on optimized experiments, the results conformed with the Langrnuir adsorption isotherm and pseudo-second-order kinetics. Among inorganic anions, SO2- and PO4- had significant inhibitory effects on MO removal in BFSAP treatment due to ion-exchange adsorption.

粒化高炉矿渣粉沥青混合料路用性能研究

为了拓宽废弃粒化高炉矿渣的利用途径,文中采用不同比例的粒化高炉矿渣粉代替矿粉后,进行AC-13C沥青混合料配合比设计,并对其高温稳定性、水稳定性和低温抗裂性等路用性能进行对比分析。结果表明,将粒化高炉矿渣粉作为填料应用于沥青混合料中,提高了沥青混合料的高温稳定性和高温水稳定性,但降低了其低温水稳定性。当粒化高炉矿渣粉替代率不超过50%时,沥青混合料的低温抗裂性可以得到提高,而当粒化高炉矿渣粉替代率超过75%时,沥青混合料的低温抗裂性降低。综合分析结论得出,AC-13C沥青混合料的粒化高炉矿渣粉替代率不超过50%。

酒钢1号高炉冷却壁长寿技术应用简析

酒钢1号高炉大修停炉检查冷却壁基本完好,5~7段铜冷却壁的使用效果明显优于8、9段铸铁冷却壁。1号高炉冷却壁使用效果较好,主要是采用了优化设计炉型、铜冷却壁、增加冷却水量提高冷却强度、联合软水密闭循环冷却系统等技术;同时,存在炉身中下部铸铁冷却壁冷却水流速偏小、冷却强度不足的问题,不易形成稳定的渣皮。认为,铜冷却壁上部的铸铁冷却壁是制约高炉长寿的重要环节,应结合高炉实际原燃料条件和操作制度优化设计,增加炉身下部铜冷却壁的高度,将铜冷却壁延伸至干湿交接部位。

高炉软水密闭循环冷却系统水温调控分析与探讨

介绍了首钢股份4 000 m~3高炉的软水密闭循环冷却系统的工艺流程、系统特点与运行效果。高炉软水密闭循环系统采用闭式冷却塔冷却降温,冷却水采用循环供水方式,通过冷却水量的合理分配,实现对软水的可靠降温。根据十年来的实际运行情况,对软水密闭循环冷却系统水温调控存在的问题进行了整改,有效提升了降温能力,提高了系统的供水安全性。

水淬高炉矿渣还原性对高硫尾砂氧化过程的影响探索研究

尾砂是选矿厂在特定的经济技术条件下,将矿石磨细,选取有用成分后排放的废弃物,是我国排放量最大的工业固废。尾砂的大量堆存不仅会形成安全隐患,还会引起占用土地、污染土地和水体等问题。利用尾砂进行矿山充填是实现尾砂大宗量消纳处置的有效途径。高硫尾砂一般指硫元素含量大于8%的尾砂,由于高硫尾砂氧化生成的硫酸根达到一定浓度后就会对水泥的硬化过程有破坏作用,导致高硫尾砂在矿山充填中的利用率较低。找到抑制高硫尾砂氧化的方法是降低高硫尾砂环境污染、提高高硫尾砂充填利用率的途径之一。本文通过开展高硫尾砂氧化试验,对水淬高炉矿渣的还原性对高硫尾砂氧化过程的影响开展了探索研究,通过观察试验结果,结合理论分析和其他学者的研究成果,可以得出结论:①高硫尾砂在水中可以发生氧化反应,主要反应过程为黄铁矿(FeS2)等硫化物与水和水中的溶氧反应生成硫酸根和氢离子;②矿渣微粉对高硫尾砂的氧化过程有抑制作用,可以显著减缓水中高硫尾砂的氧化速率;③矿渣微粉具有还原性,还原性来源是高炉中的还原性气氛,还原性的物质承担者是其中低价态的硫;④矿渣微粉抑制高硫尾砂氧化速率的原因是矿渣中低价态的硫优先与水中的溶氧发生反应,降低了高硫尾砂中硫化物的氧化速率。

大冶特殊钢2号高炉长期使用水熄焦生产实践

对大冶特殊钢2号高炉长期使用水熄焦的生产实践进行了总结,针对水熄焦使用过程中水分大幅波动、质量不稳定导致的高炉荒煤气温度低、炉温波动大、锌、碱富积以及炉缸工作状态恶化等问题,通过铁前系统的协调和内部应对操作调整,确保水熄焦使用期间炉况稳定,为直供干熄焦后高炉各参数的迅速恢复创造了条件。

国内某4000 m^(3)级高炉降料面停炉实践

以国内某大型高炉降料面停炉工作为实践背景,对整个降料面停炉过程进行分析总结,通过制订详细的停炉方案,以及停炉前精心准备,停炉过程精细操作,实现了高炉全煤气回收及快速、安全停炉,整个停炉用时6 h 50 min,精准降到目标料线,为缩短检修工期和顺利开炉创造了良好条件。

冲渣水余热在高炉脱湿鼓风方面的应用

利用负压闪蒸技术获取高炉冲渣水余热,将提取出的负压蒸汽作为溴化锂制冷机动力源制取冷水,冷水进入高炉鼓风机前端脱湿器实现高炉鼓风脱湿。将高炉冲渣水余热提取负压蒸汽技术与乏汽型溴化锂制冷实现高炉鼓风脱湿技术结合使用,解决了冲渣水利用过程中因固体杂质的存在对设备堵塞等问题,也对设备、管线的设计、控制、维护提出了更高的要求。

1#高炉配用外购焦炭生产成本分析

探讨了炼铁厂1#高炉在相同操作制度下,不同焦炭配比对高炉焦比、煤比、燃料比、返焦量的影响,并详细分析了不同焦炭配比下吨铁成本的变化,最终得出了配加价格较低的外购水熄焦高炉吨铁成本反而上升的结论。

冷却水水垢对冷却壁冷却能力影响的传热学分析

建立了高炉冷却壁冷却水与冷却壁体综合传热系数的数学模型。计算表明 :钻孔冷却壁的综合传热系数是铸管冷却壁的 2 0多倍。冷却水的水垢对冷却壁的冷却能力有重要影响 ,这种影响对钻孔冷却壁更加严重。因此 ,对于长寿高炉来说 。

冷却壁破损与水管结垢研究

高炉冷和壁进入晚期工作临界点后有一个快速破损期，为水管结垢热阻增大所致。文中讨论了水管中垢瘤的生成机理和结垢对高炉操作的影响，以及冷却壁宏观破损过程的成因。

高炉水淬渣对电镀废水中重金属和COD吸附的响应面优化

为了考察高炉水淬渣处理实际电镀废水中重金属离子和COD的可行性,分别研究了吸附剂投加量、p H、吸附时间以及温度等单因素对Cu^(2+)、Zn^(2+)或COD去除率的影响。在单因素实验的基础上,应用Box-Behnken中心组合方法进行三因素三水平试验,建立二次多项数学模型,并验证该模型的有效性。采用响应曲面法探讨吸附剂投加量、p H、吸附时间3个因子的交互作用及其最佳水平。结果表明:在吸附剂投加量为1.4g、p H为8、吸附时间为120min的最优化条件下,电镀废水中Cu^(2+)、Zn^(2+)和COD去除率达到最大,分别为99.35%、98.46%和53.63%。经对最优条件进行验证,预测值与验证实验平均值接近。吸附后废水中的Cu^(2+)和Zn^(2+)低于GB 21900—2008电镀废水新建企业污染物排放限值要求,而COD没有满足排放要求,所以仅应用高炉水淬渣吸附技术还不足以去除电镀废水中所有有害物质,因此可利用此技术作为辅助工艺,联合其他技术共同去除电镀废水中的重金属离子和有机物,使出水水质达到国家排放标准。

Cu^(2+)、Cd^(2+)、Zn^(2+)在高炉水淬渣上的竞争吸附特性

利用等温吸附法考察了高炉水淬渣对Cu2+、Cd2+、Zn2+的单组分吸附和竞争吸附性能。结果表明,单一组分吸附时,金属离子吸附等温线属于"H"形等温线,吸附平衡符合Langmuir吸附等温模型,高炉水淬渣吸附的顺序为Cu2+﹥Cd2+﹥Zn2+,这与重金属离子电负性、水合离子半径及荷径比等有关。当加入竞争离子后,Cu2+的吸附等温线基本维持原来形状,且仍旧与Langmuir吸附等温模型比较相符,而Cd2+和Zn2+的吸附无法与现有等温吸附模型很好地拟合,等温线的形状由于竞争作用也与传统的等温线均不相同,同时各金属离子的吸附量都比单组分的吸附量降低了。吸附动力学过程先是一个快速阶段,然后进入慢速阶段。无论是单组分还是竞争条件下,伪二级动力学方程拟合结果较好,说明高炉水淬渣与Cu2+、Cd2+、Zn2+之间的吸附过程主要是以化学吸附为主。

用含钛高炉渣制备肥料

以含钛高炉渣和硫酸铵作原料,采用加热法制备复合肥料,以提高其溶解性能,使其中的营养元素转化为易被植物吸收利用的形式.考察了工艺条件对肥料溶出率的影响.结果表明,合成肥料的适宜工艺条件为:硫酸铵与水淬含钛高炉渣的质量比为8∶1,加热温度为320℃,恒温时间为36 min.在此条件下,水淬渣中Ti,Mg和Fe的溶出率分别为84%,88%和75%,肥料中含有氮、硅、硫、钙、镁、铁和钛等营养元素,均可被植物有效利用,其中氮、钛、镁、铁和大部分硫以水溶性物质的形式存在,可作为速效成分.