SU1178787A1 - Method of melting aluminium scrap in induction crucible furnace - Google Patents

Abstract

ALUMINUM FLOURING METHOD: LOMA IN THE INDUCTION BATTERY CfCf) includes loading the charge into the melt induced in the crucible, melting when heated by induction currents, removing slag and metal draining, characterized in that, in order to increase the efficiency of the induction currents, removal of slag and metal draining, characterized by the fact that, in order to increase the efficiency of the heating current, the slag is removed and the metal is drained and the metal is drained. On the walls of the crucible, melt-resistant refractory pieces in the form of bricks and blocks in an amount sufficient to fill the perimeter of the crucible in one layer and with a density close to the raft are introduced into the melt before loading the charge. melt.

Description

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This invention relates to metallurgy, in particular to methods for smelting aluminum scrap using induction crucible furnaces. The purpose of the invention is to increase the efficiency of the furnace by reducing the formation of dust on the walls of the crucibles due to the removal of the melt infused during circulation. The essence of the method is as follows. In an induction crucible furnace, a melt is induced; pieces with refractory melt-resistant material with a specific weight close to the weight of the melt are loaded into it with inductors turned on. Standard refractory bricks and blocks are used as pieces; their number should be enough to fill the perimeter of the crucible in one layer. Then it is loaded into the furnace: t aluminum scrap, which is kept in the furnace until the melt is melted by heating the induction currents. When the melt is stirred by the inductor, the refractory pieces move along the walls of the crucibles and do not allow the oxides to settle on the walls of the crucibles, and the deposited oxides scrape off, therefore the growth of nastily on the walls of the crucible slows down. After melting and overheating of the melt, slag is removed, where oxides that are not deposited on the walls are removed, and the metal is drained. The refractory pieces thus remain at the bottom of the crucible. Example. In the included IAT-6 furnace containing 3 tons of liquid aluminum alloy with a density of 2.4 kg / dm, magnesite blocks were loaded in an amount of 10 pieces (200 kg) with a density of 2.4 kg / dm. Melted raw materials of 100–200 kg were periodically fed to the surface of the melt, melting was carried out before filling the crucibles. Slag was removed from the metal surface with spoons to remove slag. The temperature of the melt was brought to 750, then the metal (3 tons) was decanted, and the magnesite blocks remained in the crucible. Magnesite blocks made a movement in a circle - along the walls of the crucible to its center. During the operation of the inductor-torus. After the metal drainage, an accumulation of up to 5 mm thick was found on the walls. After 20 heats, no wear of magnesite blocks was detected. Electricity consumption amounted to 620 kWh / t. Cleaning 1 time for 4 swimming trunks. In the secondary non-ferrous metallurgy, oxidized charge is generally used. During melting, the oxides are transferred to the melt and, transported by the flows, are mixed by the electric field of the melt, in the absence of pieces, are deposited on the walls of the crucibles, increasing their thickness and resistance of the air gap, reducing the electric efficiency of the furnace. If refractory pieces are loaded into the crucible with a density close to the melt density, then the hydrodynamic forces of the flow force them to move along a trajectory passing along the walls of the crucibles. In this case, the blocks create an unstable hydrodynamic regime that prevents the deposition of oxides: fishing on the walls, and at the same time scrape precipitated oxides from the walls. . The increase in the density of the blocks leads to the deposition of them on the bottom of the crucible, the decrease in density - to finding them on the surface of the melt. Thus, the proposed method of smelting aluminum scrap reduces the thickness of the basement during the smelting process. On the walls of the crucible by 2 times due to the mechanical effect of the injected refractory bodies with a density close to the density of the liquid metal moving along the walls and scraping nastily during the smelting process, due to whereby a reduction in the reactance of the air gap of the furnace is achieved; reduction of power consumption; increase in productivity . The decrease in the share of manual labor during the purification of the walls of the crucible leads to an increase in the daily life of the furnace by 1 hour.

Claims (1)

METHOD FOR ALUMINUM Smelting: CROWBAR IN AN INDUCTION COOKING FURNACE comprising loading the charge into the melt induced in the crucible, melting when heated by induction currents, removing slag and draining the metal, characterized in that, in order to increase the efficiency of the furnace by reducing the lamination on the walls of the crucible, prior to loading, the melt-resistant refractory pieces are introduced into the melt in the form of bricks and blocks in an amount sufficient to fill the crucible perimeter in one layer and with a density close to the density of the lava.