Production of high purity cobalt oxalate from spent ammonia cracker catalyst

A process was developed to produce > 99.9% pure cobalt oxalate from spent ammonia cracker catalyst pellets containing ∼ 20% Co generated at heavy water plants. A pilot plant for producing kilograms of cobalt oxalate of required purity has been set up. The process consists of leaching, oxidation, solvent extraction, ion exchange and oxalate precipitation. The major impurities present in the leach liquor after nitric acid oxidation were Fe³⁺, Al³⁺ and Ni²⁺. Fe³⁺ and Al³⁺ were separated from the leach liquor by using a solvent extraction (SX) process employing a mixed extractant system consisting of D2EHPA and TBP. Ni²⁺ was separated by ion exchange (IX) employing Dowex M4195 resin.     

Mixing-time correlation in top gas stirred melts

An experimental study is conducted to study the factors affecting the mixing-time of a top gas stirred metal bath in absence and presence of melting scrap by a chemical decolouration model method. The results obtained on mixing-time are presented and discussed. Mixing-time results are correlated successfully with the modified Froude number.     

小高炉顶温偏低问题的分析

沙钢9号500m3级小高炉2014年顶温平均为130℃,低时只有102℃。干法布袋除尘高炉顶温的合理区间为120～250℃,因此9号炉顶温偏下限。经分析,目前操作条件下风温、燃料比对顶温影响明显。高炉热负荷对顶温影响较大,适当发展中心气流、减弱边缘气流有利于降低冷却强度、提高顶温。但是9号炉常用布料矩阵的粒度偏析较严重,不利于发展中心气流。通过适当增大40mm以上大粒度焦炭所占比例,降低焦炭反应性,以及适当增加焦丁用量等可以发展中心气流,提高顶温。     

Radial gas distribution in the blast furnace top

Blast furnace process control heavily depends on good control of burden and gas distribution. For many blast furnaces this control relies on measurements with fixed above-burden probes. Therefore, an accurate knowledge of the gas flow between stockline and above-burden probes is of paramount importance. Measurements in the blast furnace top and calculations with a mathematical model are used to shed more light on the gas flow in the blast furnace top. It turned out that complex gas flows cause several differences between data at stockline level and at above-burden probe level. There is an acceleration of gas in the furnace centre due to the much higher temperature there. Gas from the colder intermediate region is therefore attracted towards the centre. There is hardly any influence of the inclination of the stockline. It is advisable to make the distance between stockline and above-burden probes as small as possible or to use some form of in-burden measurement.     

高炉炉顶粗煤气管道研究现状

对高炉粗煤气管道的相关文献资料进行归纳总结,得出了一些结论,可为相关工程设计提供有益参考.高炉炉顶粗煤气管道的连接方式主要有"裤裆管"式、"三岔管"式和"球节点"式,在使用过程中,高炉粗煤气管道出现的问题主要集中在上升管和下降管汇合处管皮和焊缝的开裂,以及下降管本身变形过大.     

转炉顶吹气体射流的冲击特性

 利用Fluent软件研究了转炉炼钢不同枪位条件下的顶吹气体射流特性,并与理论计算结果对比分析。发现单孔氧枪数值模拟的冲击深度小于理论计算值、冲击面积大于理论计算值,且随着枪位的提高,冲击深度差值变小,冲击面积差值变大。在此基础上,研究了100 t转炉采用4孔超音速氧枪的射流冲击特性,发现当枪位为1.0 m时,冲击深度为0.21 m,冲击面积仅为1.328 m2,与计算值相差较大;当枪位提高至1.5 m时,冲击深度模拟结果为0.12 m,计算值为0.83 m,冲击面积模拟结果和计算值相差增大。     

炉顶煤气循环-氧气鼓风高炉综合数学模型

为了研究开发炉顶煤气循环μ氧气鼓风高炉炼铁新工艺,建立其综合数学模型.模型由高炉各个区域煤气成分计算方程、高炉上部空区热平衡模型、热化学平衡模型和炉身效率模型组成.用此模型计算了该炼铁工艺的基本工艺参数.结果表明:新工艺的焦比为200 kg·t^-1,煤比为200 kg·t^-1,相比传统高炉,燃料比降低22.9%;风口循环煤气量对风口理论燃烧温度影响较大,风口循环煤气量每增加10m³·t^-1时,风口理论燃烧温度降低17.6K.此外,应用此模型还可以计算任何原料和燃料等条件下的炼铁工艺参数,研究相同原料和燃料条件下的各个工艺参数的变化规律.     

澳斯麦特铜吹炼顶吹炉生产实践

对云南锡业股份有限公司铜业分公司澳斯麦特铜吹炼顶吹炉投产试车阶段的情况进行总结,叙述了出现的问题及解决措施。     

以熟石灰和纯碱为活性成分制备高炉炉顶煤气脱氯剂

用熟石灰和纯碱为活性成分制备高炉炉顶煤气脱氯剂;考察了熟石灰与纯碱的质量比、纯碱的平均粒度、黏结剂、造孔剂对脱氯剂脱氯性能和机械强度的影响,并得到最佳工艺条件.研究表明:熟石灰和纯碱双组分脱氯剂既克服了高炉煤气中CO_2气体对脱氯剂性能的不利影响,又保证了脱氯反应后脱氯剂的机械强度;纯碱的粒度越小越好;膨润土不仅可以提高脱氯剂的机械强度,还可以改善活性组分的分散性.最佳工艺条件下制得的脱氯剂在温度为150℃、空速为1000 h~(-1)和进口HCl的体积分数为0.1%条件下19.02 h后的穿透氯容量达到17.08%,同时径向抗压碎强度均值保持在60 N/cm以上.     

Medium oxygen enriched blast furnace with top gas recycling strategy

Top gas recycling oxygen blast furnace(TGR-OBF)process is a promising ironmaking process.The biggest challenge of the TGR-OBF in operation is the dramatic decrease of top gas volume(per ton hot metal),which once led to hanging-up and shutdowns in practice of the Toulachermet.In order to avoid this weakness,the strategy of medium oxygen blast furnace was presented.The maneuverable zone of the TGR-OBF was determined by the top gas volume,which should not be far from the data of the traditional blast furnace.The deviation of ±12.5% was used,and then the maneuverable blast oxygen content is from 0.30 to 0.47 according to the calculation.The flame temperature and the top gas volume have no much difference compared to those of the traditional blast furnace.The minimum carbon consumption of 357 kg per ton hot metal in the maneuverable zone occurs at the oxygen content of 0.30(fuel saving of 14%).In the unsteady evolution,the N2 accumulation could approach nearly zero after the recycling reached 6 times.Thus far,some TGR-OBF industrial trials have been carried out in different countries,but the method of medium oxygen enriched TGR-OBF has not been implemented,because the accumulation of N2 was worried about.The presented strategy of medium oxygen enriched TGR-OBF is applicable and the strategy with good operational performance is strongly suggested as a forerunner of the full oxygen blast furnace.     

高炉煤气透平机发电控制系统

南昌长力钢铁股份有限公司TRT控制系统以施耐德Quantum系列PLC为核心,实现了TRT自动启动、调整、并网、调节功率、调节炉顶压力和自动停机,在确保高炉炉顶压力稳定,保证高炉正常生产的前提下,最大限度地回收高炉煤气压力的潜在能量.     

高炉喷吹COREX脱CO2顶煤气的数值分析

 COREX脱CO₂顶煤气作为一种优质富氢气体,直接喷吹进入高炉可有效降低高炉燃料消耗。建立了高炉喷吹COREX脱CO₂顶煤气静态工艺模型,研究高炉喷气对风口理论燃烧温度、炉腹煤气量、炉腹煤气成分、风口回旋区形状、直接还原度、节焦效果等因素的影响,并进一步探究了提高风温作为热补偿措施后的适宜喷气量。研究结果表明,不采取热补偿措施条件下,随着COREX脱CO₂顶煤气喷吹量的增加,理论燃烧温度逐渐降低,炉腹煤气量逐渐升高,高炉直接还原度降低。以维持理论燃烧温度和炉腹煤气量稳定为标准,风温相对基准提高30、60、90 ℃后,可接受喷吹的煤气量为45.4、85.5、123.3 m3/t。热补偿后,随着喷气量增加,鼓风量逐渐降低,富氧率逐渐升高。炉腹煤气中的CO及H₂含量随喷气量增加而增加,每增加10 m3/t的COREX煤气喷吹量,炉腹煤气中总的还原气体体积分数增加0.46 %,直接还原度降低0.006,节约焦炭1.48 kg/t。     

柳钢烧结烟气氨法脱硫体系脱硝机理

为了揭示氨法脱硫体系中的脱硝行为,以柳钢265 m2烧结机和 360 m2烧结机为研究对象,测定并评估柳钢烧结烟气氨法脱硫系统的脱硝效率,并对吸收液进行检测,分析脱硝产物的走向。结果表明,烧结烟气中NOx主要以NO的形式存在,烧结烟气氨法脱硫体系具有一定的脱硝能力,平均脱硫率为94.30%,平均脱硝率为24.37%。在氨法脱硫体系下,主要脱硝反应为NOx被(NH4)2SO3还原为N2,其次是NOx被吸收液吸收转化为NO-3。由于NO分子的极性很弱,难溶于水,将NO转化为易溶于水的NO2是提高氨法脱硫体系脱硝率的关键。     

TRT装置顶压控制过程在高炉上料操作中的系统辨识

正常工况下高炉间歇上料所造成的料柱变化是引起高炉煤气余压透平发电装置(TRT)炉顶压力不稳定的主要因素.从机理上详细分析了TRT系统中高炉料柱变化对炉顶压力的影响,结合系统辨识的方法,建立了以透平机静叶开度和高炉料柱的料线高度为输入,以高炉炉顶压力为输出的系统动态模型,并采用TRT系统现场运行数据对所建立的模型进行了验证.结果表明,所建立的数学模型很好地描述了TRT系统中高炉上料间歇操作与炉顶压力之间的定量关系,模型辨识比较精确.     

Production of [13N]ammonia applicable to low energy accelerators

We have developed a technique for the rapid conversion of the nitrogen-13 induced in a graphite target into nitrogen oxides. This was accomplished by heating the graphite target in a stream of pure oxygen at 800 degrees C. Less than 20% of the radioactivity was found in the form of [13N]nitrogen. The rest of the radioactivity was efficiently trapped in a solid-phase medium that consisted of an aqueous solution of 5% NaOH dispersed in silica gel. The radioactivity from this solid-phase medium was eluted with water (94% recovery) and found to be in the form of 13NO2- (99%). This was subsequently converted to [13N]ammonia with Raney-nickel, either by a conventional liquid-phase reduction with an overall conversion efficiency to ammonia of 45%, or by an incorporation of the Raney-nickel into the solid-phase medium. The latter system resulted in an overall conversion efficiency to ammonia of 37 +/- 9%, with a radiochemical purity of nearly 100% and a synthesis time under 17 min.     

Numerical analysis of carbon saving potential in a top gas recycling oxygen blast furnace

Aiming at the current characteristics of blast furnace(BF)process,carbon saving potential of blast furnace was investigated from the perspective of the relationship between degree of direct reduction and carbon consumption.A new relationship chart between carbon consumption and degree of direct reduction,which can reflect more real situation of blast furnace operation,was established.Furthermore,the carbon saving potential of hydrogen-rich oxygen blast furnace(OBF)process was analyzed.Then,the policy implications based on this relationship chart established were suggested.On this basis,the method of improving the carbon saving potential of blast furnace was recycling the top gas with removal of CO_2 and H_2O or increasing hydrogen in BF gas and full oxygen blast.The results show that the carbon saving potential in traditional blast furnace(TBF)is only 38-56kg·t~(-1) while that in OBF is 138kg·t~(-1).Theoretically,the lowest carbon consumption of OBF is 261kg·t~(-1)and the corresponding degree of direct reduction is 0.04.In addition,the theoretical lowest carbon consumption of hydrogen-rich OBF is 257kg·t~(-1).The modeling analysis can be used to estimate the carbon savings potential in new ironmaking process and its related CO_2 emissions.