如何提高高碳铬铁中硫元素分析的准确性

通过改变分析条件来研究高碳铬铁中硫元素测定数据的准确性。并对测定数据的分析后，总结影响高碳铬铁中硫元素测定数据稳定性的主要原因，并提出了改进方法。     

冶炼高碳铬铁过程中合金硫的控制

介绍了宏电铁合金公司在高碳铬铁生产中通过对炉温的提升、合金碳硅的控制、渣型的调整及原燃料的合理搭配,使合金硫含量由0.08%降至0.06%以内。实践证明,炉温的提升和合理渣型调控是控制高碳铬铁合金中硫元素的有效途径。     

电热法高碳铬铁生产铬污染防治浅析

通过介绍电热法高碳铬铁生产原理和铬元素毒理性特性,分析高碳铬铁冶炼过程中铬元素流向,剖析可能引起铬污染的工序环节及途径,提出高碳铬铁生产中供今后可参考的铬污染防治措施。     

上海申佳铁合金有限公司成功开发两种优质特殊钢用铁合金

专业从事铁合金生产的上海申佳铁合金有限公司成功开发了低钛高碳铬铁和高纯铬铁两个新品种 ,为高质量特殊钢生产提供了保证。低钛高碳铬铁含钛量很低 ,用于冶炼轴承钢可有效减少钢中Ｔｉ (Ｃ ,Ｎ)杂质 ,提高钢材使用寿命。高纯铬铁具有主元素高 ,硫、磷等杂质元素低的特点 ,是微碳铬铁系列中的新品种。由于纯度高 ,可部分替代金属铬应用于冶炼不锈钢、镍基合金等特殊产品。采用热兑工艺实现工业化生产高纯铬铁在我国是首创上海申佳铁合金有限公司成功开发两种优质特殊钢用铁合金@陈兴章     

高碳铬铁合金生产中提高铬元素回收率的生产实践

本文从理论角度探讨了影响提高铬元素回收率的各种因素,从实践方面总结和提出了提高高碳铬铁铬元素的措施和方法,对高碳铬铁合金的实际生产具有很好的指导意义。     

电感耦合等离子发射光谱法(ICP-AES)测定高碳铬铁中的钛

介绍了电感耦合等离子发射光谱法测定高碳铬铁中Ti元素的试验方法。采用先加入磷酸和硝酸的混合酸溶解高碳铬铁,后用浓硝酸溶解溶液中碳化物等不溶物,冷却后,加入适量水溶解溶液中盐类,定容。用电感耦合等离子发射光谱测定溶液中Ti元素的光谱强度。配制标液建立标准曲线,使用标准曲线计算出样品中Ti的含量。该方法检测高碳铬铁中Ti的含量,准确度,精密度均符合生产检测的要求。     

含铬废水滤渣冶炼铬铁工艺研究

对含铬废水滤渣;台炼高碳铬铁的滤渣预处理、冶炼工艺方法进行了研究,研究结果表明：废水滤渣经“脱水-水洗-焙烧”预处理后,可作为冶炼铬铁的合格原料。使用废水滤渣冶炼铬铁,经电炉熔剂法生产高碳铬铁．不仅可以回收其中的有价元素铬,同时可实现滤渣的无害化处理。     

高碳铬铁冶炼中铬元素的流向分析及提高铬回收率的途径探讨

文中论述了高碳铬铁冶炼中铬元素的流向，并根据生产实际数据进行了计算，指出了提高铬回收率的途径。     

南非铬矿的理化性能及其在高碳铬铁生产中的使用

主要通过对南非系列铬矿的理化性能的分析,阐述了其在高碳铬铁生产原料中的地位,以及在高碳铬铁生产中的使用方式和使用效果,从而为生产高碳铬铁企业提供参考建议。     

高碳铬铁合金固相显微结构及破碎性能

为了研究高碳铬铁合金在浇注过程添加硅铁粉和铝后固相显微结构及破碎性能变化,在0.2 t多功能炼钢中试炉重熔某铁合金公司生产的高碳铬铁,浇注时分别添加硅铁粉和铝,分析重熔的常规高碳铬铁、添加铝及硅铁粉的高碳铬铁的固相显微结构,并将样品经颚式破碎机破碎。结果表明,高碳铬铁显微结构主要由(Cr,Fe)7C3固态相和(Cr,Fe)7Si固态相组成,有部分TiN、MnS和Al2O3夹杂物析出,常规高碳铬铁中未发现Al2O3夹杂物,而添加硅铁粉和铝的高碳铬铁中均析出了Al2O3及TiN夹杂物;添加铝的高碳铬铁组织致密,气孔率小,而常规高碳铬铁存在大量裂纹和孔洞,组织疏松,添加硅铁粉的高碳铬铁介于两者之间;经颚式破碎机破碎后,常规高碳铬铁、添加硅铁粉的高碳铬铁和添加铝的高碳铬铁破碎后粉末率分别为13.2%、11.7%和9.5%。     

从常压富氧炼锌高硫渣中回收元素硫的方法

介绍了一种从常压富氧直接湿法炼锌过程产出的高硫渣中回收元素硫的方法,利用闪蒸改变高硫渣中元素硫的晶型结构,采用热滤法生产元素硫,该法属于物理过程,工艺流程短,设备简单,操作容易,生产成本低,可以解决从常压富氧直接湿法炼锌过程产出的高硫渣中不能回收元素硫的问题,完善了锌精矿常压富氧直接浸出工艺.     

Desulphurisation of high sulphur coal to improve industrial utilisation

Abstract

Coal from northeastern India is considered to be a very good quality coking coal owing to its low ash content (<8%). It has an excellent caking property, and after carbonisation it can provide a very good CSR (coke strength, after reaction with CO₂). On the other hand, its metallurgical application is not so encouraging as a result of its high sulphur content (3-7%). Normally the acceptable sulphur content in metallurgical coke is 0·7% maximum. About 90% of the sulphur is present in organic form, and the remaining 10% as pyrites and sulphates. Removal of sulphur from the organic types is somewhat complicated as it cannot be done by any physical process such as benificiation or flotation, whereas sulphur in pyrites and sulphates can be removed by physical means. With a view to lowering the sulphur content of the coal, desulphurisation studies were carried out at elevated temperatures ranging from 400 to 950°C under the flow of various reducing gases such as coke oven gas, water gas, steam and pure hydrogen. The retention time at each temperature of experimentation was usually varied at 15, 30 and 45 min. It was observed that the sulphur content in the coal was decreased in every experiment with the various reducing gases. The extent of sulphur removal in treatment of the coal with coke oven gas was up to 78·1%, that with steam 83·1% and that with water gas 85·7%. The minimum sulphur content found in desulphurised coal was 0·86%, which could not be used for metallurgical purposes unblended. In the case of experiments with steam, a severe loss of carbon (15-20%) was observed because of reaction with the steam, whereas no such losses were observed in experiments with the other two reducing gases. Hydrogen lowered the sulphur content at a faster rate in comparison with the other gases, but could not increase the degree of reduction. The present study may help to establish the technoeconomic feasibility of the processes; however, large scale experimental studies are required for confirmation. I&S/1721     

Sulphur segregation and high-temperature brittle intergranular fracture in alloy steels

High temperature brittle intergranular fracture has recently been identified as a mode of failure in alloy steels. It is associated with the dynamic segregation of sulphur to cracks in hard microstructures stressed at elevated temperatures in a manner analogous to hydrogen embrittlement at ambient temperature. Several models have been proposed to describe the action of sulphur, but insufficient experimental data have been available for their evaluation. The present study characterises sulphur enrichment at cracks and on free surfaces at high temperature in detail using scanning Auger spectroscopy. Both intergranular and transgranular surfaces were studied at pressures of air from 10⁻⁹ to 10⁻³ torr. Two types of sulphur enrichment at cracks were identified; general segregation to crack faces and local enrichment close to crack tips. The source of sulphur was largely that dissolved in the ferrite matrix. Large sulphides, intersecting grain boundaries, made a minor contribution, while small “overheated” intergranular sulphides were inoperative as sulphur sources. The role of stress in encouraging sulphur segregation was confirmed. In addition, an intermediate pressure of air was found to enhance sulphur enrichment, but only at surface oxygen coverages of 15–25 at.%. These observations were generally consistent with the influence of the crack tip stress field on migration of the sulphur solute, described by the “pure drift” model of high temperature brittle intergranular fracture. Refinement of the model, using finite element stress analysis, is included.     

高碳铬铁冶炼脱硫的实践

文章从理论上分析了高碳铬铁合金中碳、硅、硫含量的相互关系，炉渣碱度对合金含量的影响，提高炉温对炉渣脱硫的作用以及焦炭含硫量的影响等。并以此为依据制定了降低高碳铬铁含硫量的具体措施。同时介绍了采取上述措施所取得的效果。     

降低转炉法中碳铬铁硫含量的探讨

论述了影响转炉法中碳铬铁含硫量的主要因素,指出了降低转炉法中碳铬铁含硫量的措施。     

The age-related characteristics of feather formation in birds and the physiological role of sulfur as sodium sulfate in keratin synthesis in the plumage

There were studied formation's processes of feathering in chickens and goslings and role of sulphur sulphate in synthesis of keratin's feathers. It is established, that sulphur sulphate sodium is used for synthesis of precursors of keratin's feathers. The including of 35S-sulphate natrii regulates the intensity of feather's growth. The content of sulphur in amino acids containing sulphur in feathers of chickens for period from 1 till 60 days of age is increasing from 6.34 to 94.47 per cent. Fattening in composition of feed the sulphate natrii stimulates by chickens and goslings the intensity of feather's growth and metabolism of sulphur in skin.     

硫浮选工艺流程的改进与工艺条件优化

通过现场流程考察和分析,将硫浮选工艺流程由原来一粗一扫一精选改为二粗一扫一精,使硫粗选前三槽刮出泡沫直接进入硫精矿池,同时优化硫浮选工艺操作条件,制定相应生产操作卡片,不仅保证了硫精矿的质量,而且提升了硫浮选系统的处理能力,提高了硫的回收率,使硫浮选系统工艺指标基本达到设计要求(硫精矿品位36％,硫回收率46％)。     

Optimisation of ladle slag composition by application of sulphide capacity model

Abstract

The sulphur distribution ratio for ladle slags at Ovako Steel AB has been determined by calculating the sulphide capacity using the Royal Institute of Technology (KTH) model and the alumina activity via an empirical expression suggested by Ohta and Suito, and by using the well established theories for sulphur refining. A parameter study was carried out based on plant data from a previous study on desulphurisation. The effect of carbon and aluminium in the steel, the temperature of the steel, and alumina and lime in the slag on the sulphur distribution ratio was investigated. It was shown that the Al₂ O₃ /CaO ratio had the largest influence on the conditions studied, and that when it increased the sulphur distribution ratio decreased. Based on these results, new plant trials were carried out, in which the alumina content in the slag was changed. The calculated sulphur distribution ratios for these trials were found to be in good agreement with experimentally determined sulphur distribution ratios. It is concluded that the present approach can be used to optimise multicomponent ladle slags with respect to sulphur refining.     

巯基乙酸钠在锌硫分离中的应用

江西荡坪钨业有限公司宝山矿区为夕卡岩白钨多金属硫化矿,矿山选厂现有的浮选工艺流程中使用了氰化钠以改善硫锌分离效果,但该有氰工艺属于国家明令淘汰的落后工艺。对该矿的锌硫分离分别采用了单一氧化钙、添加氰化钠和添加巯基乙酸钠抑制磁黄铁矿、黄铁矿的比较试验;完成了使用巯基乙酸钠在高pH矿浆中用硫酸铜活化闪锌矿,以石灰作为磁黄铁矿、黄铁矿的抑制剂,辅之以巯基乙酸钠的小型闭路试验及工业生产试验,获得了锌精矿品位45.10%、回收率94.39%的选矿指标;该锌硫精矿的无氰分离工艺符合国家环保要求。     

Control of sulphur for spring steel killed by Si–Mn and with low basicity slag

Experiments are carried out in the case of low basicity slag for spring steel killed by Si and Mn, then the changes of the sulphur content, the sulphur distribution ratio L_S and inclusions are investigated. Finally, the effect on desulphurisation of oxygen content in molten steel, the calculated and measured lgL_S and the deep desulphurisation of the vacuum degassing station are discussed. It is found that the most sulphur in liquid steel is mainly removed during the early stage of LF refining. The average sulphur content in steel and the sulphur distribution ratio after the soft bottom-blown are 0.0047% and 115, respectively. It is very accurate and credible to use the L_S model to predict L_S. During the early stage of LF refining, to reduce the oxygen content in steel quickly is very crucial for the rapid desulphurisation of the Si and Mn killed spring steel with low basicity slag. The desulphurisation of molten steel can be further carried out during the VD refining station and it is beneficial to reduce the sulphur content for the control of sulphide in spring steel killed by Si–Mn and with low basicity slag.