Phosphorus: The Noose of Sustainability and Renewability in Steelmaking

With rising ore prices and the continued demand for higher quality steels, much work has been carried out into refining and control prospects of steel chemistry. As several technologies around the world are exploring the control of phosphorus with high priority, an overview of current knowledge, ongoing research, and specific interest areas is presented. The reliance of the basic oxygen furnace steelmaking on iron ore quality is considered with regard to impurity levels, as well as the phosphorus content of direct reduced iron introduction to the electric arc furnace process. This article reviews methods to control phosphorus in steelmaking and proposes a practical approach based on laboratory-scale equilibrium experiments. The article ends by exploring energy savings in steelmaking as well as speculating on further avenues of steel production profitability.     

钢渣的综合利用

钢渣是炼钢工业的副产品。细述了钢渣的理化特性,并介绍钢渣在筑路、烧结矿、水泥、建材和农业等领域的综合利用。     

VD炉内轴承钢中碳还原渣中CaO的热力学及影响因素分析

铝酸钙是轴承钢中比较常见的点状夹杂,它会降低轴承钢的使用寿命。利用Lupis—Wagner方法,计算了在VD炉冶炼期间碳还原渣中CaO的可能性,讨论了真空度和温度等对碳还原渣中CaO影响钢中钙含量的因素。结果表明VD炉中,轴承钢中的碳能还原渣中的CaO生成[Ca]从而与钢中Al2O3结合生成点状的铝酸钙夹杂。炉渣碱度对钢中Ca含量影响比较大,此外提高温度和真空度均可增加钢中的含Ca量。     

新一代洁净钢生产流程的理论解析

通过对新一代洁净钢生产流程中主要元素选择性氧化还原的热力学分析,并结合首钢京唐公司铁水"全三脱"生产洁净钢的技术实践,研究了新一代洁净钢生产流程中S,P,C等主要元素的控制规律,并对新一代洁净钢生产流程进行了理论解析,提出了需要进一步解决的若干工艺问题.研究表明:采用CaO/CaF2脱硫剂的KR法脱硫,可使铁水中S含量稳定地降到0.0020%以下,终点硫的控制主要取决于脱磷转炉中的回硫量,减少废钢和渣料等辅助材料带入的S以及适当提高脱磷炉渣碱度是减少半钢回硫量的关键;在较低温度(1300 1350℃)和较高氧位条件下造碱度合适的渣,是脱磷转炉实现脱磷保碳的关键,对于冶炼普通低磷钢,将脱磷炉半钢P控制在0.03%以下,则可将脱碳转炉终点磷控制在0.006%以下,而对于冶炼超低磷钢,则需将半钢P含量控制在0.008%以下,转炉终点磷可以降低至0.0020%以下;脱碳转炉少渣冶炼、降低铁耗以及高碳出钢是新流程降低洁净钢生产成本和提高钢液洁净度的重要技术特征.     

冶炼不锈钢泡沫渣的实验研究

从理论上阐述冶炼不锈钢时熔渣的发泡机理。并根据上海三钢公司的情况，在2500Hz的中频感应炉上时熔渣进行发泡高度的实验，找出发泡性能较好的渣系，研究渣中各成分对发泡性能的影响。     

Immobilization of Cr (VI) in stainless steel slag and Cd,As, and Pb in wastewater using blast furnace slag via a hydrothermal treatment

The immobilization of hexavalent chromium in stainless steel slag using blast furnace slag as the immobilizing agent and by performing a hydrothermal treatment was investigated. The results showed that there was no immobilization in the absence of the blast furnace slag. On the other hand, the hexavalent chromium in stainless steel slag could be immobilized through the hydrothermal reaction when blast furnace slag was used at 250 °C for 24 h. A leaching test was performed to evaluate the degree of immobilization of hexavalent chromium in the products formed by the hydrothermal reaction. It was found that the degree of immobilization was very high. Based on the results obtained, the immobilization mechanism of hexavalent chromium in stainless steel slag, resulting from the hydrothermal treatment of blast furnace slag, could be elucidated. Finally, the immobilization of cadmium, lead, and arsenic using blast furnace slag as the immobilization agent was also studied while focusing on the effects of the hydrothermal treatment.     

不锈钢电弧炉粉尘直接还原回收工艺研究

电弧炉粉尘巳被列为有害废物，直接还原回收粉尘中有价金属不仅可保护环境，而且可充分利用宝贵的金属资源。采用中频感应电炉模拟电弧炉冶炼工艺进行了A、B、C和D系列实验研究。通过气体成分的检测、钢锭和炉渣的成分分析，了解工艺参数对还原过程的影响，认为电弧炉粉尘直接还原回收工艺切实可行，不影响钢产品质量，为该新工艺的生产实践提供了依据。     

水钢预应力钢绞线SWRH82B钢的冶炼工艺

水城钢铁集团公司根据GB/T24238- 2009质量标准和用户使用要求,确立了预应力钢绞线SWRH82B钢的内控成分（质量分数）：w(C)=0.79%～0.84%、w(Si)=0.15%～0.30%、w(Mn)=0.60%～0.90%、w(P)≤0.025%、w(S)≤0.015%、w(Cr)=0.25%～0.27%。采用高炉铁水→100 t顶底复吹转炉冶炼→LF炉精炼→150 mm×150 mm方坯连铸的工艺流程生产SWRH82B方坯,用于轧制SWRH82B盘条。采用的质量控制方法有：（1）采用含铝量低的合金脱氧,减少钢中的Al2O3夹杂物含量;（2）采用低氮增碳剂、低氮铁合金对钢水进行脱氧合金化,LF炉采用微正压操作,造好泡沫渣,埋弧精炼,连铸采用全封闭保护钢水浇注,使成品钢中的氮质量分数降到40×10-6以内;（3）将中间包钢水过热度控制在15～30 ℃,结晶器电磁搅拌频率5 Hz、电流320 A,铸坯拉速（1.73±0.02） m/min,二冷段气雾冷却比水量0.62 L/kg,将铸坯中心各种缺陷级别之和控制在3级以内。     

邯钢低磷钢生产技术的开发及应用

通过对转炉冶炼脱磷的机理进行分析,采取合理控制冶炼过程温度、熔渣碱度和氧化性等技术措施来强化转炉脱磷,优化合金种类、减少出钢下渣和加钢包顶渣等措施减少钢水回磷,实现了低磷钢的大批量生产,并且成功应用于新品种钢的生产开发。     

Reduction mechanism of stainless steelmaking dust and carbon pellets

1 INTRODUCTIONThe smelting temperature generally reaches1 600 ℃or higher in stainless steel making opera-tion. Under this condition,approxi mately 1 % 2 %(mass fraction) of the scrap charged into the fur-nace is converted to dust[1]as by-product of steel-making process .It has been assigned as a hazard-ous waste and banned from landfills by variousgovernment regulatory agencies because it containsa lot of heavy metals such as zinc ,lead,cadmium,chromium and nickel , which will be leached …     

渣-金界面气泡夹带行为数值物理模拟EI北大核心CSCD

利用物理模拟和数值模拟研究气泡和熔渣不同物性参数对气泡在渣-金界面夹带量的影响。研究结果表明,影响气泡夹带量和渣-金界面面积的主要因素是气泡直径,其次是渣层密度,渣黏度和界面张力对气泡夹带影响相对较小。气泡初始直径由10 mm增大到16 mm,气泡夹带量增大了7.41倍,渣-金界面面积增量最大值增大3.67倍。渣层密度由2000 kg/m^(3)增大到5000 kg/m^(3),气泡夹带量增大了62.3%,渣-金界面面积最大值增大了13.1%。渣-金界面张力和黏度增大,气泡夹带量和渣-金界面面积均降低。渣-金界面张力从0.65 N/m增大到1.10 N/m,气泡夹带量减小了30.6%,渣-金界面面积最大值减小6.4%。渣层黏度由0.05 Pa·s增大到2.0 Pa·s时,气泡夹带量降低18.4%,渣-金界面面积最大值减小10.2%。     

Cupola Oxygen Steelmaking at Acme Steel

Operating experience for a unique hot-blast cupola — basic-oxygen jurnace steelmaking facility is described. The facility is unusual in that basic, hot-blast, water-cooled cupolas are used to produce a low-silicon hot-metal for the basic oxygen furnaces. The problems encountered in using low-silicon hot-metals are discussed.Because of the low silicon content of the cupola hot-metal, steelmaking operations at Acme are different than at other basic oxygen facilities. The various steelmaking techniques employed, including the use of an artificial slag, are described in detail.     

钢渣矿渣水泥性能的研究

以钢渣、矿渣、水泥熟料为主要原料,并掺入少量激发剂,成功制备了高强、高钢渣掺量的钢渣水泥。探讨了激发剂、熟料掺量、钢渣掺量对钢渣水泥性能的影响。并通过SEM、XRD分析了激发剂对钢渣水泥水化产物及水泥石微观结构的影响。结果表明:激发剂显著提高了钢(矿)渣的活性,从而大幅度提高了钢渣水泥的早期性能。掺加激发剂后,钢渣水泥3d抗压强度可增加119.7%,激发剂对水泥水化产物的种类影响不大。与硅酸盐水泥相比,钢渣水泥浆体中C-S-H凝胶和AFt晶体含量明显增多,Ca(OH)2晶体含量显著降低。     

Corrosion and Corrosion Inhibition of Reinforcing Steel: II. Embedded In Concrete

Abstract

Reinforcing steel, whether embedded in Portland concrete or Portland cement-blast furnace slag concrete and mixed with distilled or tap water, becomes passivated. On the other hand, when the concrete is mixed with sea water, the steel corrodes severely, and when Helwan mineral water is used for mixing, a borderline condition is obtained. Portland cement-blast furnace slag concrete had poorer corrosion resistance compared with ordinary Portland cement concrete.

Steel passivity is not impaired when Portland cement concrete or Portland cement-blast furnace slag concrete is admixed with up to 8% of sulphates. However, when cement extract is used, the passivity is impaired when as little as 0·2% of sodium sulphate is added.

Additions of some anodic inhibitors such as benzoate, chromate, nitrite, phosphate and stearate to a corrosive concrete medium are efficient in preventing the corrosion of reinforcing steel. The critical concentration for inhibition is higher in the case of Portland cement-blast furnace slag concrete than that of Portland cement concrete. Coating the steel with Portland cement slurry alone or Portland cement slurry containing inhibitors improves the corrosion resistance of steel to some extent but does not inhibit the corrosion in strong attacking media.     

低碳钢高拉速板坯保护渣的工业试验与应用

提高连铸机拉速是炼钢产线提率的有效手段,而连铸保护渣是高拉速连铸技术中的重要技术环节。从保护渣的理化性能、使用性能和使用效果等方面对3种低碳钢高拉速保护渣(I、II、III)在工业现场开展了对比研究。通过初步工业试验发现,保护渣III的液渣层厚度合理、消耗量高、摩擦力低、传热能力强、饱和热通量高、热轧板卷的夹渣指数低。将保护渣III用于低碳钢板坯高拉速常规化生产,以1.80~1.95 m/min的拉速共浇注500多炉低碳钢,未发生黏结报警,夹渣降判率仅为0.47%。     

BLAST FURNACE SMELTING WITH HIGH MgO SLAG

高炉在用18.5％MgO的炉渣进行冶炼时,炉子比较顺行,炉温比较稳定。但由于炉渣的脱破能力较弱,必须提高炉渣的总碱度((CaO+MgO)/SiO_2)。 本文着重地分析了高MgO渣冶炼时焦比升高的原因。理论计算证明将白云石直接装入高炉时由于带入炉中的CO_2量(每吨铁)增加了15％,导致了高炉的直接还元率以及因此的焦比的升高。应将白云石作为烧结原料。     

An oxygen steelmaking process

High carbon, low phosphorus steel can now be made from pig iron containing 0.7 pct P or more, in a commercial sized open hearth furnace. No external heat is required for refining, and steel produced is identical with basic open hearth steel.     

Recovering flake graphite from steelmaking kish

As part of its research efforts to encourage conservation and reuse of natural resources, the U.S. Bureau of Mines has developed a process to produce high-quality flake graphite from the steelmaking waste known as kish. The kish produced by current steelmaking practices is a mixture of graphite, desulfurization slag, and iron that is skimmed from the molten iron feed to the basic oxygen furnace. Kish was treated by a combination of screening and hydraulic classification to produce a concentrate containing more than 70% graphite. Acid leaching of the concentrate gave a graphite product with 95–99% purity and a flake size ranging from 10 mesh down. Industrial graphite users indicated that kish graphite is a suitable substitute for natural graphite material for most uses.     

中间包流场数值模拟

针对邯钢三炼钢8机8流方坯连铸机中间包,通过建立数值模型,研究在设置挡渣墙和坝前后以及不同的挡渣墙情况下,中间包内钢水流场规律,并通过RTD曲线分析了连铸中间包内挡渣墙和坝对其钢液流场的影响,为优化方坯中间包钢水流场积累了很好的技术经验。