脱硫剂粒度对铁水脱硫的影响试验

 通过不同粒度脱硫剂的铁水脱硫试验,结合实际生产中脱硫渣微观结构的分析,探讨了脱硫剂粒度对铁水脱硫的影响。结果表明,随着脱硫剂粒度的减小,铁水脱硫量、脱硫率和脱硫速率常数均随之增大。脱硫渣结构分为3层：外层主要为脱硫产物CaS,厚度为10~50μm;中间层主要为2CaO·SiO2;内核为未反应的CaO。粒度越小,石灰颗粒利用率越高。为保证较好的脱硫效果和提高利用率,建议将脱硫剂粒度控制为0.5~1.5mm。     

粒度对石油焦硫含量分布及煅烧脱硫的影响研究

通过库伦滴定法分别测定不同粒度石油焦的硫含量及其煅烧后的硫含量。结果表明,粒度对不同硫含量石油焦中硫含量有影响,且差异较大,硫含量2.54%石油焦可筛分出硫含量2.25%石油焦(粒径-0.5mm),3.35%石油焦可筛分出硫含量2.33%石油焦(粒径-0.15mm),硫含量5.98%石油焦筛分的作用较小;粒度对石油焦脱硫具有明显差异,粒度+0.5mm的2.54%石油焦脱硫效果较好,粒度+1mm的3.35%石油焦脱硫效果较好,整个粒度范围内5.98%石油焦脱硫效果差异不大。     

粒度对高硫铝土矿焙烧脱硫的影响

在不同矿石粒度下,探究焙烧预处理对矿石宏观形貌、粒度分布、硫含量、物相结构及矿物微观形貌的影响。结果表明,较粗粒径的盘磨矿的焙烧效果优于较细粒径的球磨矿;焙烧后矿石粒度有细化的趋势,其中盘磨矿中的黄铁矿被氧化成赤铁矿,颗粒变得较为疏松,球磨矿中含有微量的磁铁矿;在700℃、30min的焙烧条件下,矿石的硫含量从2.3%降低至0.48%,满足工业生产要求。     

Particle Size Distribution and Metal Content in Street Sediments

Sediments that had accumulated during the winter season, and which were left at the surface when the snow had melted, were studied with regard to physical and chemical characteristics. The investigation was carried out in the city of Lule?, which is located in northern Sweden. Sediment samples were collected in the city center and in a housing area at streets with different traffic loads. The results showed that the amount of the sediments at a street surface was evidently affected by the presence of a sidewalk. The street with a sidewalk accumulated much more sediment than the street without a sidewalk did. Both of these streets had approximately the same traffic load. The sidewalk also affected the particle size distribution. The content of heavy metals in the sediments varied with the traffic load and the area type. The highest concentration of cadmium, lead, and zinc was found in the street with the highest traffic load.     

铜冶炼企业重金属污染物粒径分布特征研究

对某铜冶炼企业铜冶炼有组织源和无组织源进行监测研究,并利用AERMOD空气质量模型对企业重金属污染物扩散情况进行模拟,通过对铜冶炼企业环境空气质量浓度预测值与监测值的拟合结果来验证铜冶炼企业废气中重金属污染物粒径分级的合理性。结果表明,污染源粒径分级参数的选择对铜冶炼企业重金属污染物的空气质量浓度计算结果有显著影响;当采用"双闪"工艺的铜冶炼企业重金属污染物铅、铜、砷、锌粒径参数质量百分比为25%、质量中位径为8μm时,AERMOD空气质量模型能较好地模拟该企业重金属污染物的扩散。     

铅冶炼企业重金属污染物粒径分布特征研究

对某铅冶炼企业的有组织源和无组织源进行监测研究,利用AERMOD空气质量模型模拟重金属污染物扩散,通过拟合废气中重金属污染物的预测值与监测值,研究铅冶炼企业废气中重金属粒径的分布特征。     

Study of New Hot Metal Desulfurization Process on 1t Desulfurization Experiments

For the lack of the present hot metal desulfurization processes in iron and steel industry, our group has proposed the in-situ mechanical stirring method for external desulfurization of molten iron and researched this new method. This paper investigated this new in-situ mechanical stirring hot metal desulphurization process on desulphurization experiments of one-ton scale by using the new desulfurizer. The experimental results indicated that the desulfurization efficiency of in-situ mechanical stirring desulfurization process is 90% and the lowest sulfur content in the treated hot metal is 23ppm. By comparing with the methods of direct throwing desulfurizer and in-situ injecting desulfurization, in-situ mechanical stirring desulfurization process is the suitable desulfurizaton method.     

爆炸烧结中金属粉末颗粒的尺寸效应

采用环状飞片柱面收缩爆炸方法,研究了FT15高速钢粉末在冲击波作用下,因粉末粒度的差异而引起的颗粒效应:在动态冲击载荷的作用下金属细粉比粗粉吸收的能量多,温度高,致使细粉比粗粉表层更易熔化,熔化量也相对增加。同时发现在FT15高速钢混合粉爆炸烧结后粉末中的大颗粒与小颗粒的变形规律不同。     

Study on the Possibility of Using ZnO for Hot Metal Desulfurization

The possibility of using ZnO for desulfurization in hot metal was evaluated. A lab scale experimental setup was designed so that different desulfurizing agents could be added to hot metal for evaluation of their desulfurizing power. The setup had good control of both temperature and the gaseous atmosphere. It also provided stirring of the metal bath with an impeller as well as quenching facility to maintain the metal composition at high temperature. Desulfurization of hot metal using CaO powder showed evidently the applicability of the new setup. On the other hand, additions of ZnO into the hot metal under various experimental conditions showed no effect on desulfurization. The results were in contradiction to the suggestion found in literature. A thorough examination of the thermodynamic data employed by the previous work was carried out. The data used in the literature were found to be subjected to fundamental mistakes. The present experimental results convincingly rule out the possibility of using ZnO as a desulfurization agent.     

Study of MgO-Based Desulfurizer in Hot Metal Desulfurization

This paper has investigated a new desulfurizer for iron and steel industry to make up the lackness of magnesium-based desulfurizer. In order to explore the desulfurization process of hot metal by the new desulfurizer, both the thermodynamics and experiments have been studied.. The results of thermodynamics indicated that, under the standard condition,the lowest reaction temperatures of MgO + C and MgO +Si were 1846℃ and 2132℃ and the pressure of Mg vapor at the hot metal temperature were 0.2-0.5kPa and 0.005-0.01kPa, respectively. In the case of reaction between MgO and Al, the calculated starting reaction temperature under standard condition was 1475 ℃, and the pressure of Mg vapor was distributed from 27 kPa to 45kPa at the hot metal temperature, showing that it was easy to happen the reaction of MgO+Al. The experimental results displayed that the desulfurization efficiency was only 42.31% by the desulfurizer of MgO and C, while the effect of MgO+ Al and MgO+ Al-Si was good, since the desulfurization efficiencies were above 85%, and the lowest sulfur content was below 40×10-6.     

镁基石灰复合喷吹铁水脱硫技术的工艺优势

客户对于高品质钢的不断需求推动着铁水外部脱硫技术的发展。从相对简单的机械搅拌法到较成熟的喷吹技术,炼钢工作者不断地在生产成本和操作效率之间寻求最佳的平衡点。镁和石灰复合喷吹法是一项经过生产实践证明了的成熟技术,为炼钢生产者们提供了一种可靠的、可重复且满足生产需要的经济脱硫方法。     

Effect of Gas Forming Compounds on the Vibration of a Submerged Lance in Hot Metal Desulfurization

Hot metal desulfurization is the main process step for removing sulfur in blast furnace-based steelmaking. A desulfurization reagent is pneumatically injected into the hot metal through a submerged lance causing it to vibrate. The aim of this study is to develop a mechanical vibration measurement-based method that can detect changes in the gas-forming properties of the reagent. The detection is performed using Elastic Net regression and eXtreme Gradient Boosting-based classification models the classification performance of which is compared. The lance aging causes changes in its dynamic characteristics, and the disturbing effect of this is removed from the measured data of the lance vibration prior to classification by means of a developed cleaning algorithm. The best classification performance in detecting changes in the gas-forming properties, with an area under the receiver operating characteristic curve of 0.916 and Matthews correlation coefficient of 0.699, is achieved using an Elastic Net regression-based classification model. The results of this work serve as a basis for developing industrial applications in which the effective utilization of the excitation, such as vibrations generated by the gas formation can be utilized for process monitoring and as a soft sensor for predicting the reagent-induced process variance.     

喷吹法铁水脱硫反应动力学分析研究

为取得较好的铁水脱硫效果,首先要按照脱硫反应热力学选择脱硫剂,但脱硫效果很大程度上还决定于反应动力学条件,因此对镁、碳化钙和石灰脱硫剂进入铁液中的条件、在铁液中的上浮速度、停留时间、溶解时间分别进行了理论计算与分析,计算结果为确定脱硫工艺与装备提供参考.     

Desulfurization of Hot Metal by the Injection of High-Quality Lime Powder

The desulfurization of hot metal by the injection of fluidized lime (≥94% CaO) is analyzed, when the lime consumption is 0.5–19 kg/t of hot metal. That results in 95% desulfurization; the lowest sulfur content in the hot metal is 0.003%. Decrease in sulfur content in the hot metal to 0.005, 0.010, 0.015, 0.020, and 0.025% with different initial sulfur content is observed, with the injection of different quantities of lime. Sulfur content below 0.001% is not observed and not guaranteed. Recommendations are made for optimal desulfurization of hot metal by lime. Their adoption increases the desulfurization, decreases the losses of hot metal and the temperature, and decreases the consumption of materials and the cost of the process.     

Particle Size Distribution of Lunar Soil

Meteorite impact on the lunar surface produces a consistent, broadly graded soil. In this note, the geotechnical and geological systems are compared to characterize lunar soil. In geotechnical terms, the lunar soil particle size distribution is described as sandy silt/silty sand, well-graded. In geologic terms, it is described as very fine sand, very poorly sorted, nearly symmetrical, and mesokurtic. Because of its broad particle size distribution, lunar soil may be internally erodible.     

Effects of Particle Size on Nitridation Kinetics of Manganese Powder

Isothermal thermo-gravimetric analysis was applied to investigate the nitridation kinetics of manganese powder with different particle sizes at 800,900 and 1 000℃.The apparent activation energy and nitridation kinetics equations of manganese powder with different particle sizes were obtained from unreacted shrinking core model and Arrhenius formula.It was found that the nitridation mechanism was controlled by interfacial chemical reaction.The apparent activation energy and the apparent rate constant of nitridation reaction were affected by particle sizes.With the decrease of particle size,the apparent activation energy decreased whilst the apparent rate constant increased.It was suggested that the refinement of the manganese powder contributed to the increase of molar surface energy,which accounted for the lower apparent activation energy.     

铁水脱硫用钙镁系粉剂的研究

论述了钙镁系粉剂在铁水脱硫过程中的反应机理及其优点,并提出了提高脱硫效率的途径。