摘要:
During the production of stainless steel, a slag is formed during the melting of the solid material in the electric arc furnace, the slag having a high degree of metal oxides, particularly chromium oxide. The chromium concentration often reaches values of more than 30%. Currently, such slags cannot be reduced to a desired degree due to their composition. In order to minimize the resulting high loss of recyclable material, the invention provides to charge the electric arc furnace with pellets, or briquettes (8), which are made of a defined mixture of an iron carrier as the ballast material, carbon, or carbon and silicon, as the reducing agent, and a binder, wherein they react beneath the slag layer (7) in the steel melt (6) with the metal oxides of the slag (7), particularly with the chromium oxide present, in a floating, chemical, and reducing manner. The reaction gases (12) produced in the process, which are mainly made of carbon monoxide, advantageously support a foaming of the slag (7).
摘要:
The invention concerns a method for treating steel in an electric arc furnace for forming a foamed slag at the surface of the liquid steel, which consists in injecting into the slag or in its vicinity powder calcium carbide in an amount between 3 and 8 kg per ton of steel in the furnace. It enables the reduction of iron loss in the slag, in particular when the charge contains direct reduced iron, and the decrease of energy consumption.
摘要:
A composition comprising from 35 to 50 wt-% of C, from 10 to 20 wt-% of Al, from 25 to 40 wt-% of Al 2 O 3 , from 0 to 3 wt-% of CaO and from 0 to 3 wt-% of MgO, provided however that the combined amount of CaO and MgO is of from 1 to 6%. A process for preparing such composition as well as a process for using such composition in the melting of scrap iron in an electric furnace.
摘要:
Procédé de valorisation de la scorie de four électrique d'aciérie, qui consiste à ajouter à la scorie, à l'état liquide, un composé porteur de silice et d'alumine ainsi qu'un agent réducteur qui lui confèrent, après réduction des oxydes, une composition voisine de celle du laitier de haut fourneau. Ce composé est de préférence constitué par des cendres volantes, contenant au moins 20 % de carbone imbrûlé. L'agent réducteur utilisé est le carbone sous forme de charbon broyé. On maintient la scorie à l'état liquide et à une température comprise entre 1500°C et 1700°C, au moins partiellement par chauffage à l'arc électrique, éventuellement assisté par un brûleur d'appoint. On peut encore ajouter à la scorie diverses matières finement divisées contenant des oxydes de métaux, telles que des poussières d'aciérie ou de haut fourneau, des pailles de laminoir ou de la scorie LD.
摘要:
A method for the continuous production of steel, semi steel, or hot metal in a multi-stage continuous electric furnace configuration where tapped alloy from the primary electric furnace could be processed further with or without use of a secondary step for removal of carbon and silicon, for example a basic oxygen converter, and where this primary electric furnace is connected in some way to a secondary electric furnace in which the slag from said primary electric furnace is processed to ensure maximal iron recovery as well as maximal potential use for the slag, its' components, and its' energy content, even including the processing of internal and external material streams.