Modeling of trajectory and residence time of metal droplets in slag-metal-gas emulsions in oxygen steelmaking

In basic oxygen steelmaking, the major portion of the refining is realized through reactions between metal droplets and slag. The residence time of metal droplets in the slag crucially influences the productivity. A model for the prediction of trajectory and residence time of metal droplets in slags has been developed based on mechanics and chemical kinetics principles. When there is no decarburization, analysis of the ballistic motion of metal droplets in the slag predicts very short residence times (<1 second). This result demonstrates that when decarburization is very weak, the metal droplets spend a very short time in the slag. This could explain in part the poor kinetic behavior in the end stage of the blow. During active decarburization metal droplets normally become bloated, resulting in a decreased apparent density. Accounting for this, the ballistic model predicts residence times ranging from 10 to 200 seconds, which are much more in keeping with practical experience and previous laboratory studies. Excellent agreement between the model and laboratory measurements, combined with reasonable predictions of industrial residence times, shows that this model can be used to provide a much improved understanding of theoretical aspects of oxygen steelmaking.     

Maintenance of metallurgical equipment

Improvement in the reliability of welding equipment at OAO Izhstal’ on the basis of engineering diagnostics and scheduled maintenance is considered.     

冶金企业实验室建设

冶金企业实验室建设应考虑温度、湿度、震动、给排水、供电等因素的影响,使各种环境条件满足实验室建设的需要.     

Processing of metallurgical slags

Magnitogorsk Metallurgical Combine. Translated from Metallurg, No. 10, p. 38, October, 1990.     

Failure of metallurgical sinter

Strength tests of sinter associated with the optimization of sinter production have certain deficiencies, whose analysis calls for models of sinter failure. The theory of melt mixing in sintering and structure formation in the sinter cake is reviewed. A model for the failure of metallurgical sinter is proposed on the basis of a model of the stress state of the solid inclusions in the matrix and a failure model based on the Rittinger law. The load in the sinter pieces in the test drum is determined, and a method is proposed for adapting the model of sinter failure by means of granulometric data regarding the test products. The adaptation employs the probability distributions of the model parameters. The dependence of these parameters on the sinter basicity, the carbon content in the batch, and the size of the limestone pieces is determined.     

Multiple emulsions

The purpose of this review is to update the information on multiple emulsions known to be promising delivery systems for both pharmaceuticals and cosmetic materials. The possibility of encapsulating active substances within liquid membranes may lead to interesting opportunities in both fields. Thus the formulation, manufacturing, stabilization, analysis and potential application of multiple emulsions seems to be worth surveying, putting a special emphasis on cosmetic applications.     

标准推动了冶金企业环保发展

结合钢铁行业生产工艺,分析污染物产生的原因,总结治理成果,阐述标准对行业污染排放所起的作用。     

Green metallurgical processing of chromite

A new green metallurgical process for chromite ore has been proposed and developed to solve the serious environmental problem in the traditional production process of chromate. In the new process, the oxidation of chromite ore is carried out in sub-molten potassium hydroxide at 300 °C. Compared with the traditional roasting process in a rotary kiln at 1200 °C, the oxidation and mass transfer are greatly intensified in the new process. Chemical conversion of chromium is above 99% and the recovery of chromium is raised by more than 20% while the reaction temperature is dropped by 900 °C. Thus the energy consumption is decreased. Furthermore, as no limestone or dolomite additives are required, the amount of chromium-containing residue is decreased from 2.5 tonnes to 0.5 tonnes with the production of 1.0 tonne of product in the new process. As all reactions and separating operations are performed in liquid media, pollution due to toxic dust is prevented.With the change of reaction medium, the new process achieves higher resource and energy utilization efficiency. At the same time, the new process also changes the physical and chemical properties of other components co-existing in the chromite ore. The process provides the possibility for virtually complete utilization of chromite and zero emission of residue. Thus, the clean production of chromate can be realized.