钙铁橄榄石渣系在铜锍顶吹吹炼工艺的应用

侯马冶炼厂使用铜锍顶吹吹炼工艺生产粗铜,生产初期采用常规的铁橄榄石渣系,在实际生产中因为铁橄榄石炉渣在高氧势条件下磁铁含量高,易导致炉渣泡沫化,甚至造成严重的安全生产隐患。为了有效控制炉渣泡沫化,在顶吹吹炼炉试验了钙铁橄榄石渣系,试验证明,钙铁橄榄石渣系对固态磁铁的析出能够起到很好的控制作用。     

CFD Modeling of Swirl and Nonswirl Gas Injections into Liquid Baths Using Top Submerged Lances

Fluid flow phenomena in a cylindrical bath stirred by a top submerged lance (TSL) gas injection was investigated by using the computational fluid dynamic (CFD) modeling technique for an isothermal air–water system. The multiphase flow simulation, based on the Euler–Euler approach, elucidated the effect of swirl and nonswirl flow inside the bath. The effects of the lance submergence level and the air flow rate also were investigated. The simulation results for the velocity fields and the generation of turbulence in the bath were validated against existing experimental data from the previous water model experimental study by Morsi et al.[1] The model was extended to measure the degree of the splash generation for different liquid densities at certain heights above the free surface. The simulation results showed that the two-thirds lance submergence level provided better mixing and high liquid velocities for the generation of turbulence inside the water bath. However, it is also responsible for generating more splashes in the bath compared with the one-third lance submergence level. An approach generally used by heating, ventilation, and air conditioning (HVAC) system simulations was applied to predict the convective mixing phenomena. The simulation results for the air–water system showed that mean convective mixing for swirl flow is more than twice than that of nonswirl in close proximity to the lance. A semiempirical equation was proposed from the results of the present simulation to measure the vertical penetration distance of the air jet injected through the annulus of the lance in the cylindrical vessel of the model, which can be expressed as L_va = 0.275( d_o - d_i )Fr_m^0.4745 . L_{va} = 0.275left( {d_{o} - d_{i} } right)Fr_{m}^{0.4745} . More work still needs to be done to predict the detail process kinetics in a real furnace by considering nonisothermal high-temperature systems with chemical reactions.     

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.     

RH-PTB真空精炼装置内粉剂混合特性的水模型研究

根据相似理论,用1∶9水模型钢包(直径0.43m,水面高度0.45m)模拟RH-PTB真空精炼水冷顶枪喷粉技术,研究顶枪气量、上升管提升气量、顶枪枪位高度对粉剂混均时间的影响。结果表明,随顶枪气量增加,粉剂在液体中均混时间增加,并具有最大值;随提升气量增加,均混时间迅速减少,但当提升气量≥15L/min时,均混时间不再继续减少;顶枪枪位对均混时间有一定影响,实际操作中,应根据具体情况,调整顶枪枪位,以减少粉剂均混时间。     

钢水真空精炼顶枪的电气控制设计与实现

针对目前国内冶金行业钢水精炼中的顶枪装置发生变频器故障时,导致顶枪无法快速自动提升至真空槽外,且易引起顶枪枪体被烧坏,研发出了一种新型顶枪升降装置控制电路,可提高顶枪装置的安全性和可靠性。     

Assessment of Electromagnetic Stirrer Agitated Liquid Metal Flows by Dynamic Neutron Radiography

Metallurgical and Materials Transactions B - This paper presents qualitative and quantitative characterization of two-phase liquid metal flows agitated by the stirrer on rotating permanent magnets....     

Three-Dimensional Numerical Simulation and Analysis of Flows around a Submerged Weir in a Channel Bendway

To improve navigation conditions for barges passing through river channels, many submerged weirs (SWs) have been installed along the bendways of many waterways by the U.S. Army Corps of Engineers. This paper presents results from three-dimensional numerical simulations that were conducted to study the helical secondary current (HSC) and the near-field flow distribution around one SW. The simulated flow fields around a SW in a scale physical model were validated using experimental data. The three-dimensional flow fields around a SW, the influence of the SW on general HSC, and the implication of effectiveness of submerged weirs to realign the flow field and improve navigability in bendways were analyzed. The numerical simulations indicated that the SW significantly altered the general HSC. Its presence induced a skewed pressure difference cross its top and a triangular-shaped recirculation to the downstream side. The over-top flow tends to realign toward the inner bank and therefore improves conditions for navigation.     

Polymer-Derived In-Situ Metal Matrix Composites Created by Direct Injection of a Liquid Polymer into Molten Magnesium

We show that a liquid organic precursor can be injected directly into molten magnesium to produce nanoscale ceramic dispersions within the melt. The castings made in this way possess good resistance to tensile deformation at 673 K (400 °C), confirming the non-coarsening nature of these dispersions. Direct liquid injection into molten metals is a significant step toward inserting different chemistries of liquid precursors to generate a variety of polymer-derived metal matrix composites.     

Parametric Instability of a Liquid Metal Sessile Drop Under a High Frequency Amplitude-Modulate Magnetic Field

The parametric instability behavior of a liquid mercury sessile drop under high frequency Amplitude-Modulate Magnetic Field(AMMF),i.e.a high frequency magnetic field(carder wave)modulated by a low frequency sine wave(modulate wave),is investigated experimentally.The free surface contour of the mercury drop is observed by a CCD camera while varying the frequency and amplitude of the high frequency AMMF.At a given frequency and amplitude,the edge deformations with an azimuthal wave numbers(modes n=3,4,5,6)were excited.     

X-ray TV study of the penetration of tin into a steel melt

A technique is developed and an X-ray TV study is performed to investigate the penetration of spherical tin samples into the steel 40Kh melt at a temperature of 1550°C. Cold spherical tin particles 1–2 in weight are found to dissolve in the tin-free steel at an initial rate of 180 ± 50 mol/(m² s). A sample dissolves fully in less than 2 s. When a sample reaches the steel–gas phase interface, its dissolution rate decreases by many times. Separation with the formation of a two-phase system occurs at 1.6–1.9 mol % tin in steel. The density of the iron-based alloy is lower than that of the tin-based alloy. Pure tin and the saturated solution of iron in tin wet Al₂O₃-based refractory ceramic better than pure iron or its alloy with tin.     

An Experimental Study of a Bubble-Driven Liquid Metal Flow Under the Influence of a Rotating Magnetic Field

In this study we investigate the flow structure in a liquid metal cylinder while a bubble-driven flow is superposed with a rotating magnetic field(RMF).Argon gas is injected through a nozzle into a column of the eutectic alloy GalnSn.Without electromagnetic stirring the bubble plume in the centre region of the cylindrical vessel produces a recirculation with high velocities near the free surface while the fluid velocities in the bottom region remain rather low.The measurements revealed the potential of the RMF to control both the amplitude of the meridional flow and the bubble distribution and to provide an effective mixing in the whole fluid volume.Various periodic flow patterns were observed in a certain parameter range with respect to variations of the magnetic field strength and the gas flow rate.     

Sintering Time Dependent Supersolidus Liquid Phase Sintering Behaviour of a Metal Injection Molded Nickel-Base Superalloy

Metallurgical and Materials Transactions A - Supersolidus Liquid Phase Sintering of a high refractory metal Ni-based superalloy revealed that the liquid fraction and associated grain growth...     

The Impact of a Vertically Travelling Magnetic Field on the Flow in a Cylindrical Liquid Metal Bubble Plume

This article describes laboratory experiments for the investigations of flow structures and related transport processes in liquid metal bubbly flows under the influence of a traveling magnetic field (TMF). The melt flow is driven by central gas injection into a cylindrical container filled with the low-melting-point alloy GaInSn. The velocity fields of both the liquid and the gaseous phase were measured nonintrusively using the ultrasound Doppler method. Depending on the traveling direction of the magnetic field, the TMF mainly imposes either a concurrent flow or counterflow with respect to the original bubble-driven circulation. In general, the application of a downward TMF significantly increases the liquid velocity all over the fluid volume. An upward TMF gives rise to the more complex structures of the velocity field resulting in alternately arranged upstream and downstream regions. Both the upward and downward TMF promote the occurrence of nonsteady motions with distinct velocity fluctuations leading to an intensification of related transport processes in the melt and providing the perspective of enhanced mixing efficiencies.     

钢包喷吹新型合成粉剂的试验研究

研究出一种新型合成粉剂来代替Ｃａ－Ｓｉ粉。在车轴、硬线等网种进行试验，经过冶金效果分析，力学性能分析、认为这种新型合成粉剂效果良好，并且价格低廉，大大降低了成本。