SU1708861A1 - Method of remelting of metal ships - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular to the remelting of non-briquette metal shavings. In order to reduce chip waste and increase the yield of good cast iron, the iron chips are loaded into the molten iron in the mixer, after which the iron from the cast iron coedg is poured onto the chips, the amount of cast iron chips loaded into the mixer is 5-8% of the mass of cast iron, which is 5-8% of the mass of cast iron, loaded into the mixer, 5–8% of the mass of cast iron, and 5–8% of the mass of cast iron are loaded into the mixer and 5–8% of the mass of cast iron is loaded into the mixer and 5–8% of the mass of cast iron is loaded into the mixer and 5–8% of the mass of cast iron is loaded into the mixer and 5–8% of the mass of cast iron is loaded into the mixer and 5–8% of the mass of cast iron is loaded into the mixer and 5–8% of the mass of cast iron is loaded into a mixer and 5–8% of the mass of cast iron is loaded into a mixer and 5–8% of the mass of cast iron is loaded into a mixer. in the chips, 1.5-3.5%, and the temperature of the pig iron poured into the miser should be higher than its temperature in the mixer by 50-60 ° C. 1 tab.

Description

This invention relates to ferrous metallurgy, in particular to the remelting of non-briquette metal shavings.

The purpose of the invention is to reduce chip loss and increase the yield of good cast iron.

Cast iron in the mixer is a powerful heat accumulator. When cast iron chips are loaded into the molten iron and the iron is subsequently drained from the iron ladle, the chips are mixed with the melt and. since it is dispersed, it melts and dissolves at a high speed — until the end of the pig iron discharge from the ladle, the fully loaded chips completely melt. When silicon, which is contained in the chip in increased amounts, interacts with slag oxides, it is partially oxidized, as a result of which additional heat is released to compensate for the cost of melting the chip. Part of the cost of heat is compensated by overheated iron, poured into the mixer from the ladle.

Intensive mixing contributes to the average composition. After a short shutter speed of -15 minutes, the cast iron is poured into the ladle and sent to the steelmaking shop.

If the amount of cast iron chips loaded into the mixer is less than 5% of the mass of cast iron, the efficiency of the method decreases, since the amount of additional pig iron produced in the mixer is insignificant, the cost reduction in this case is small. In addition, when this decreases, the intensity of the stirring of the chips and the pig iron and the dissolution of the chips decrease.

In case the amount of chips loaded into the mixer is more than 8%, the temperature of the cast iron in the mixer decreases and additional heating is required, the accumulators increase, and the yield decreases (oxidizing environment, exposed metal).

If the silicon content in the chips is less than 1.5%, then when interacting with the slag as a result of exchange reactions, the silicon content decreases, as a result the chemical heat of the iron decreases, and additional energy costs are required to bring it to the required parameters.

When the temperature of the cast iron poured into the mixer is less than 50 ° C above its temperature in the mixer, the rate of melting and dissolution of chips decreases, the process involves smaller amounts of cast iron in the mixer, which reduces the efficiency of the method, to compensate for heat losses, additional energy costs are required - burning of Uplev .

When using the Method, the construction of special units and the use of special heat sources are not required. The melting of iron chips is carried out due to the heat accumulated by the iron in the mixer with the intensive mixing of chips and iron. ,

Example. Testing of the method was carried out in experimental-industrial conditions. In a mixer with a capacity of 1300 tons of cast iron chips in the amount of 2.7-5.1 tons (4.58, 5% of the mass of cast iron poured into the mixer) were loaded into the cast iron through a loading device. After this, 60 tons of pig iron were poured from the iron ladle at a temperature above (the temperature of the iron in the mixer is 1320 ° C). The silicon content in the chips ranged from 1.2 dB to 3.5%.

After holding in the mixer for 10–20 min, the cast iron was poured into a ladle and used in steelmaking in open-hearth furnaces. Characteristics of the experimental and comparative heats are given in the table.

These heats show that the best results correspond to the variant in which 6.5% (3.9 tons) of iron chips are loaded into the cast iron mixer, the content

silicon in chips 2.5%, the temperature of the iron in the ladle when draining the mixer to 1380 ° C (60 ° C above the temperature of the iron in the mixer). The cost of remelting chips at the same time were minimal, and the yield - the maximum (97%).

The proposed method can be used to produce pig iron with subsequent use of it in steel smelting plants. It allows efficient use of cast iron bargings in sufficiently large quantities in steel mills.

Claims (1)

Claims The method of melting metal shavings, including pouring pig iron into a mixer and subsequent supply of metal shavings and cast iron to it, characterized in that, in order to reduce the waste of the chips and increase the yield of suitable cast iron, iron chips with a silicon content of 1.5-3.5 are used as shavings. %, which is served in the amount of 5-8% by weight of the cast iron, after which iron is additionally poured with a temperature of 50-60 ° C above the melt temperature in a mixer.