SU1573030A1 - Method of roasting limestone - Google Patents

Abstract

The invention relates to mining metallurgy, specifically to methods for calcining limestone by discharging liquid slags from ferroalloy production disintegrating during cooling. The aim of the invention is to increase the efficiency of the process by utilizing the heat of waste slags. It is proposed to bake the slag flowing directly from the furnace. The release of slag lead cycles with a break between them 1 - 3 minutes During the break between slag releases, lime is fed to the slag layer. Maintain the thickness of the limestone layer equal to 100 - 150 mm, and its mass ratio to the produced slag in the range of 0.6 - 0.8. Due to the layering of limestone and slag, the duration and uniformity of the temperature conditions of the process increase, which ensures the content of CAO in lime 89–93%. 1 tab.

Description

The invention relates to the field of ferrous metallurgy, in particular, to methods of calcining limestone by discharging liquid slags from ferroalloy production disintegrating during cooling.

The aim of the invention is to increase the efficiency of the process by utilizing the heat of waste slags.

Calcination of limestone is carried out with slag flowing directly from the furnace. Slag discharge is carried out in cycles with a break of 1-3 minutes. In this case, a layer of limestone with a thickness of 100–150 mm is fed to the layer of pork in the interval between cycles. The mass ratio of limestone to very-.

 rare slag production is maintained at 0.6-0.8.

Calcination of limestone with molten slag flowing to limestone directly from the furnace is more effective, since its temperature is higher than that of slag released from the furnace into the ladle, and from it to limestone, which is in the slag.

The layering of limestone and slag allows to increase the calcination time of limestone and provide more uniform temperature conditions of the process.

The duration of the break between the releases of the next portions of the shpak is determined by the duration of the intensive

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releasing carbon dioxide from limestone by pouring hot slag onto it, followed by slag boiling. Duration of boiling Delivers 1-2.5 minutes, the interval between the next slag discharge for more than 3 minutes does not affect the final result and leads to an undesirable lengthening of the slag discharge time from the smelter „

The choice of limits for the thickness of the layer of limestone and the ratio of the masses and its drunk slag were established experimentally.

Example ,, During the discharge of slag from the furnace to the bottom of the slag bowl, 1 portion of slag is poured and from the bunker with a wide gate, moving the bunker with a crane, pour a portion of limestone about limestone into the slag. depending on the size of limestone (if the size of the pieces is 5-20 mm, the height of the layer is 10

15

20

From the end of the rotating drum to another bunker, the Lime obtained by burning limestone is subsequently used to melt ferrovanadium in an electric furnace

The results of testing the method are given in table0.

According to TU after calcination, the content of lime CaO must be at least 85%. The proposed method, even at a lower level of slag / limestone ratio, ensures almost 89% guaranteed. At this slag layer level, a decrease in the layer of limestone less than 100 mm is accompanied by a decrease in productivity. Taking into account the thermal conductivity of limestone, an increase in the thickness of its layer of more than 150 mm leads to a sharp deterioration in the degree of burning, even with an increase in the mass of slag being poured.

The method provides for the production of CaO in lime within 89-93%, with

forest support is equal to 100-25; this firing is carried out at the expense of 120 mm, with a particle size of 20-40 mm, the layer height is 130 150 mm). Then a layer of limestone is poured over the slag and an exposure time of 1-3 minutes is made to effect the calcination of limestone. At this point, a large amount of limestone is extracted from the limestone.

thirty

carbon monoxide and slag boils. After boiling, the next portion of lime is supplied, and

heat of waste slag, which was previously lost when it was cooled.

Claims (1)

Invention Formula The method of burning limestone, including pouring a layer of material with liquid slag, maintaining the ratio of their masses, characterized in that, in order to increase the efficiency G - - L T ™ 1. TC- - on it a portion of slag "Method of completing the process due to the use of heat 0 five 0 From the end of the rotating drum to another bunker, the Lime obtained by burning limestone is subsequently used to melt ferrovanadium in an electric furnace The results of testing the method are given in table0. According to TU after calcination, the content of lime CaO must be at least 85%. The proposed method, even at a lower level of slag / limestone ratio, ensures almost 89% guaranteed. At this slag layer level, a decrease in the layer of limestone less than 100 mm is accompanied by a decrease in productivity. Taking into account the thermal conductivity of limestone, an increase in the thickness of its layer of more than 150 mm leads to a sharp deterioration in the degree of burning, even with an increase in the mass of slag being poured. The method provides for the production of CaO in lime within 89-93%, with this firing is carried out by heat of waste slag, which was previously lost when it was cooled. Invention Formula The method of burning limestone, including pouring a layer of material with liquid slag, maintaining the ratio of their masses, characterized in that, in order to increase the efficiency - - are poured on limestone to the last portion of slag After 12-16 hours, the slag cools down, turns into powder, its mixture with the obtained lime from the slag bowl is turned over into a rotating drum with a sieve, the cells of which are 5 mm. Slag spills under the drum in one bunker, and lime the size of pieces more than 5 mm dumping 0 slag slabs, roasting is carried out with slag flowing directly from the furnace, slag production is carried out in cycles with a break between them for 1-3 minutes, and lime is fed to the slag layer during the drain break, while the thickness of the limestone layer is maintained equal to 100150 mm, and its mass ratio to produced slag is within