Metal Oxidation Control at the Stage of Refining Steel Smelting in Electric Arc Furnaces

The mathematical processing results of a number of EAF-135 melts electrical parameters are presented. The influence of the foamy slag formation, molten metal carburization and the harmful impurities oxidation on the change in electrical parameters is analyzed. The methodology for determining the metal oxidation from the electrical melt parameters is characterized. In the presented form, the technique is cumbersome for the rapid assessment of the oxidation process intensity and requires refinement. Keywords: Metal oxidation, electric parameters, electric arc furnace

Ladle Steel Slag in Activated Systems for Construction Use

The construction industry needs to reduce greenhouse gases, in which cement production is currently responsible for generating between 4% and 6% of the total CO2 released into the atmosphere. Similarly, many industries produce large amounts of solid waste, which often have low value-added applications or are directly taken to landfills, with consequent negative environmental impacts. One of these industries is the steel industry, which in 2016 generated 18.4 Mt of slag (melting and refining slag) among all European Union countries. In terms of refining steel slag (ladle or white slag), it is estimated that for each ton of steel, between 20 and 30 kg of slag is produced; that is, in 2016, more than 700,000 tons of white slag were generated. It is also known that this material has cementitious properties and can be used as a precursor in alkaline activation processes. Depending on the concentrations used of the activating agent, a higher or lower mechanical performance of the developed materials can be obtained. This work studied the alkali activation of a ladle slag used to manufacture mortars, subjecting them to an initial curing of 24 h at different temperatures (20, 40, and 70 °C). Sodium silicate and sodium hydroxide were used as activating agents, using percentages of Na2O between 5% and 10% to obtain an optimal dosage of the activator. The physical and mechanical properties of the mortars were evaluated at different ages of curing. In addition, monitoring was undertaken of linear shrinkage due to drying and the mineralogical changes due to activation and curing time.

Estimation of rheological characteristics of dual phase fluid at high temperature utilizing transfer learning

Steel, when first refined and put into widescale use changed construction and engineering. Skyscrapers, mega bridges and other massive structures reinforced with this miracle material changed skylines all over the world and opened the door for vast improvements in infrastructure. Steel is still a major component of building projects today and the steel beam is often considered as one of the impressive feats of human engineering. Steel is what chemists and engineers refer to as an alloy, meaning it is a composite material of several different elements. This alloy is mostly made with iron and carbon but can contain other elements as well. The blending of these elements with iron, the base metal of steel, gives it a high tensile strength at a low cost of production, making it the transformative material we know today. However, this metal is not without drawbacks as the process of refining steel generates several difficult to deal with by-products. Professor Noritaka Saito, who is based in the Department of Materials Science & Engineering, at Kyushu University in Japan, is looking at developing accurate ways to measure the properties of these mixtures so that industry can more efficiently produce precise composite materials.

Experimental studies of the melting points of CaF2, pegmatite, and mixtures thereof with lime

Nowadays, one of the pressing issues is the problem of reducing material and energy costs in the production of certain types of products. Of particular importance are issues of slag formation due to the development of a ladle furnace (LF) plant for smelting special and alloyed steel grades with stringent requirements for the content of harmful impurities. Therefore, the question of choosing the rational composition of the slag-forming mixture (SFM) requires special attention. The aim of this work is to carry out research to solve the problems of improving the quality and competitiveness of manufactured metal products. The paper presents analytical and experimental studies of the phase composition and melting temperature of the CaF2-CaO system, which is the basis of the slag-forming mixture for refining steel in a ladle at domestic metallurgical enterprises. Previous studies on the replacement of fluorspar in the SFM with mineral raw materials of the domestic field showed that the alternative is the use of pegmatite from the Eliseevskoye field (Zaporizhzhya region). This contains alkali metal oxides Na2O and K2O, which affect both the decrease in slag viscosity of metallurgical production and the effect of desulfurization of the metal melt. Experimental studies of the melting points of fluorspar, pegmatite, and mixtures thereof with lime have been performed. Also, corundum and periclase-carbon refractory, which is usually used for lining the slag belt of LF buckets, were used as a substrate on which the process of melting of the studied materials and their mixtures took place. It is shown that pegmatite favorably affects the process of lime rarefaction and the formation of slag melt and can be used as a component of the SFM. The use of pegmatite can completely or partially replace fluorspar in the composition of the slag mixture with lime.

Experiments on Effect of Red Mud-Based Slag on Distribution of Sulfur in Liquid Iron

Preliminary research has shown that red mud is a viable option to be used as a fluxing agent in the steelmaking process, as it is able to achieve similar results as fluxes currently used in steel refining. This research focused on how red mud can be used as a flux for refining steel. Desulfurization was conducted with aluminum additions and temperature variations. The results showed that experiments utilized waste residues from the aluminum industry as refining flux for steel refining; more than 95% sulfur reduction was achieved; increasing temperature and aluminum content can improve desulfurization.

Control Method of Preventing Splashing in the Process of BOF Refining Steel Based on Soft-Measuring Technology

This article raise a new control method to prevent splashing in the process of BOF refining steel, the method is based on soft-sensing technology, use the infrared temperature measurement device installed in the top gun and bottom gun, on-line detect the temperature difference of liquid slag surface and molten steel in the furnace, with the temperature difference we can get FeO content in the liquid slag, according to the degree that occur away from the splashing, temperature range is quantified five intervals, according to fall into the interval based on the temperature difference, adjust the top-gun position and the intensity of supplying oxygen and argon, to control carbon-oxygen reaction rate and FeO content in the slag, add auxiliary material in order to improve liquid slag mobility and oxidation when foam degree of liquid slag is too high or in the “back to dry” interval, in order to prevent splashing.