RU56990U1 - SALT FURNACE FOR SECONDARY MAGNESIUM Smelting - Google Patents

Abstract

The technical solution relates to the metallurgy of non-ferrous metals, specifically, to the secondary metallurgy of magnesium. The known furnace has been improved in order to reduce losses of magnesium with bottom residues and increase furnace productivity. The salt-heated furnace includes a lined shaft with electrodes and overlap, a melting and refining chambers separated by a partition and communicating with each other under the partition, and a hydroclone with a supply, upper and lower drain pipes is installed between the walls and the bottom in the refining chamber, the distance of the hydrocyclone from the bottom is 0.1-0.5 depth of the refining chamber along the axis of the hydrocyclone, and the drain upper pipe may be above or below the ceiling.

Description

The utility model relates to non-ferrous metallurgy, specifically, to the production of secondary magnesium from scrap and metallurgical waste. The furnace can be used in the smelting shops of magnesium and its alloys.

A known salt-heated furnace for smelting secondary magnesium according to A.S. USSR No. 1769571, consisting of a melting and refining chamber, separated by a solid partition that does not reach the bottom. The bottom of the refining chamber is sloped towards the melting chamber, and the horizontal section of the refining chamber decreases from the bottom up.

A disadvantage of the known furnace according to A.S. USSR No. 1769571 is the need for the sludge of metal in the refining chamber for 30-60 minutes for cleaning from suspensions and significant loss of metal with sludge from the smelter (metal content in the sludge is 15-30%).

The proposed utility model is an improvement of the known furnace according to A.S. USSR No. 1769571 in order to reduce its inherent disadvantages.

To do this, a hydrocyclone is installed in the refining chamber between the walls and the bottom with a supply, upper and lower drain pipe, and the distance of the lower pipe from the bottom of the hydrocyclone is 0.1-0.5 times the depth of the refining chamber along the axis of the hydrocyclone, and the drain pipe can be located under the ceiling and speak on it.

The figure shows a furnace with a lining 1, electrodes 2, a melting 3 and a refining chamber 4, divided by a partition 5, and the hearth 6 is made with a slope. In the refining chamber, a hydrocyclone 7 with a feed 8, a drain 9 and a lower 10 nozzles is installed. Height h is 0.1-0.5

the depth of the refining chamber, and the drain pipe 9 can be brought out above the floor 11 (as in the figure), and end under the floor.

An improved furnace operates as follows. In the melting compartment there is a molten salt to approximately 0.15 of the furnace depth from the floor, into which the mixture is loaded in the form of scrap or metallurgical waste (for example, crucible residues) for melting at a temperature of 660-720 ° C. After the charge is melted, a centrifugal pump is installed in the melting compartment, its pipe is connected to the supply pipe of the hydrocyclone and the surfaced sludge is pumped together with salt through the hydrocyclone. In a hydrocyclone, the mixture is separated into light fractions (metal and, partially, salt) and heavy oxide-salt fractions. The light part of the melt flows through the drain pipe 9 immediately into a separate container, as shown in the figure, or on the surface of the melt in the refining chamber (in case the drain pipe ends under the overlap), and the heavy, slurry part is lowered onto the hearth and through it into the melting chamber . The pump can be pumped through a hydrocyclone as the upper, clarified part of the melt from the melting chamber, and the lower, sludge part of the melt, removing metal from it.

When installing a hydrocyclone lower than 0.1 of the depth of the refining chamber, the lower pipe may get into dense sludge networks, which creates additional hydraulic resistance for the pump. When installing a hydrocyclone higher than 0.5 depth of the refining chamber, the degree of use of its volume is deteriorated.

The advantage of installing a hydrocyclone in a salt melt is, firstly, the fact that it warms up well, and, secondly, that careful sealing of the connection between the pump pipe and the supply pipe of the hydrocyclone is not required.

A series of tests of a furnace with a hydrocyclone showed that the melting time was reduced by 20-30 minutes, and the metal content in the "dump" sludge of the smelting department decreased to 5-10%, i.e. 2-3 times.

Claims (4)

1. A salt-heated furnace for smelting secondary magnesium, including a lined shaft with overlap, electrodes, a melting and refining chamber separated by a partition and communicating with each other under the partition, and the bottom of the refining chamber is sloped towards the melting chamber, characterized in that a hydrocyclone with a supply, upper and lower drain pipes is installed between the walls and the bottom of the refining chamber. 2. The furnace according to claim 1, characterized in that the distance of the hydrocyclone from the bottom is 0.1-0.5 of the depth of the refining chamber along the axis of the hydrocyclone. 3. The furnace according to claims 1 and 2, characterized in that the drain upper nozzle of the hydrocyclone is located above the ceiling. 4. The furnace according to claims 1 and 2, characterized in that the drain upper nozzle of the hydrocyclone is below the ceiling.