The present invention concerns the field of refining metal melts or slags and provides in particular a reactive material based on calcium aluminate and carbon, its process of preparation and various methods for refining metal melts using the same.

A melting pot includes a pot body and a float salvaging apparatus. The pot body is provided with a melting chamber having an open upper end. The float salvaging apparatus includes a hanging bracket, a bearing plate, a rotating plate and a drive assembly configured to drive pivoting of the rotating plate. The hanging bracket is disposed above the melting chamber. The rotating plate is pivotably disposed on the bearing plate, and the bearing plate and the rotating plate are provided on the hanging bracket between an initial position and a first salvaging position in a manner of moving up and down. The drive assembly is connected to the rotating plate.

Raw material feed into an electric arc furnace (EAF) is melted into heated liquid metal at a controlled temperature with impurities and inclusions removed as a separate liquid slag layer. The heated liquid metal is removed from the EAF into a passively heatable ladle wherein it is moved into a refining station where they are placed into a inductively heated refining holding vessel and wherein vacuum oxygen decarburization is applied to remove carbon, hydrogen, oxygen, nitrogen and other undesirable impurities from the liquid metal. The ladle and liquid metal is then transferred to a refining station/gas atomizer having a controlled vacuum and inert atmosphere wherein the liquid metal is poured from an inductively heated atomizing holder vessel into a heated tundish at a controlled rate wherein high pressure inert gas is applied through a nozzle to create a spray of metal droplets forming spherical shapes as the droplets that cool and fall into a bottom formed in the chamber. Spherical powder comprising the droplets are removed from the chamber through screen and blenders and then classified by size.

Proposed is a method for efficiently desulfurizing molten metal in a short time without passing an excessive current when applying a potential difference between slag and metal. Using a direct-current power source, this method for desulfurizing molten metal applies a potential difference between molten slag and molten metal through electrodes, of which one electrode contacting the molten metal serves as a negative electrode and the other electrode contacting only the molten slag serves as a positive electrode. An applied current density J.sub.a is determined according to an equilibrated S concentration [S].sub.e0 before application of a potential difference such that an equilibrated S concentration [S].sub.ea when a potential difference is applied becomes equal to or lower than a target S concentration [S].sub.ft.

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al.sub.2O.sub.3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

Provided is a molten steel treatment device and a molten steel treatment method using same. The molten steel treatment method may include: preparing slag on molten steel; contacting a first electrode to at least a portion of the slag and a second electrode to at least a portion of the molten steel; and polarizing the slag by applying a voltage to the first electrode and the second electrode, to easily remove inclusions and impurity elements in the molten steel by controlling basicity and oxidation degree of the slag without using separate additives.

A method for smelting low-phosphorus high-manganese steel based on reduction dephosphorization of ferromanganese is provided in the present application, relating to the technical field of high-manganese steel smelting, where the dephosphorization of ferromanganese is carried out under reducing atmosphere conditions through mediate-frequency induction furnace to obtain molten ferromanganese with lower phosphorus content, which is subsequently mixed with low phosphorus molten steel obtained by smelting in oxidative period of electric arc furnace in LF ladle refining furnace to make the Mn content of steel reach the requirement of high-manganese steel, and smelting is carried out under the condition of reducing atmosphere by adjusting the composition and temperature of the molten steel to meet the requirements of the target composition of the steel grade before tapping the steel.

The invention is directed to a method for processing asbestos-containing steel scrap into useful products, which products can be handled in a safe manner. In accordance with the present invention the asbestos-containing steel scrap is melted in a furnace, which results in destruction of the asbestos fibers. It has been found possible to carry out such a process in an economically feasible manner. In accordance with the invention asbestos-containing steel is heated to high temperature so that the steel melts. As a result the asbestos will be converted into harmless material, which allows for safe handling and processing of the resulting products.

A process for smelting high-speed steel by using an intermediate frequency furnace-LF furnace-VD includes: firstly, melting a steel material in an intermediate frequency furnace, smelting until the steel material is melted, adjusting chemical components, and then performing deoxidation and slagging; performing electric heating for steel tapping, sending the steel tapping into an LF furnace for smelting, heating to 1470-1510? C., and adjusting the chemical components; and finally, sending these components into a VD furnace for vacuum treatment, and performing steel tapping after the components are qualified. A slagging process in the intermediate frequency furnace is used, then the coarse adjustment of chemical components, the primary deoxidation, and the slagging are performed in the intermediate frequency furnace. After the molten steel is sent to the LF furnace, the slag adjustment can be performed. A content of oxygen in the molten steel can be controlled within 10 ppm after the VD vacuum treatment.

A method for desulfurizing molten steel comprising taking a sample out from molten steel after tapping from a converter or during secondary refining and analyzing the sample rapidly with high accuracy by a method comprising a high frequency induction heating step wherein the sample is combusted and oxidized under the high frequency induction heating in an oxygen atmosphere having an oxygen purity of 99.5 vol % or more to convert S in the sample into SO.sub.2 and an analyzing step wherein SO.sub.2-containing gas produced in the high frequency induction heating step is analyzed through an ultraviolet fluorescence method to quantify S concentration of the sample.