KR20190071373A - Apparatus and method for treating lime - Google Patents

Abstract

Provided are an apparatus and a method for treating calcium oxide in a converter, which can prevent calcium oxide of small particles from being inserted into the converter by separately collecting the calcium oxide of small particles in advance, thereby allowing the calcium oxide of small particles to be re-used in the converter. The apparatus comprises: a hopper in which calcium oxide to be supplied to the converter is stored; a screen installed in an insertion unit inserting the calcium oxide of the hopper into the converter and separating particle calcium oxide with a grain size of equal to or less than 5 mm; a collector installed in the lower portion of the screen and collecting the separated particle calcium oxide; a storage hopper connected to an outlet side of the collector and allowing the particle calcium oxide to be stored therein; and a re-treatment unit supplying the fine calcium oxide stored in the storage hopper to a nitrogen spray coating unit coating the inside of the converter and inserting the particle calcium oxide to the inside of the converter.

Description

[0001] APPARATUS AND METHOD FOR TREATING LIME [0002]

A quicklime treatment apparatus and a treatment method of a converter are disclosed.

In general, the refining of the converter is performed by supplying the main raw material of the scrap iron wire to the inside of the converter and supplying the oxygen to remove carbon, silicon, phosphorus and manganese which are impurities in the iron wire by the oxidation reaction.

Among the impurities, carbon reacts with oxygen and is removed as carbon monoxide gas. Silicon, phosphorus, manganese, and the like are removed as oxides by slag. Quicklime is added to remove these impurities. The amount of calcium oxide varies depending on the silicon dioxide so as to match the basicity ratio. The basicity is the ratio of silicon dioxide and quicklime reacted with silicon.

The quicklime is received and stored on the hopper on the upper portion of the converter, and then injected into the converter through the chute by a necessary amount. The burnt lime is differentiated by collision or breakage from the transport to the process of injection, and the particle size becomes smaller.

Since the small sized lime is injected into the converter and is not made of molten steel, the basicity of the molten steel is lowered, which leads to the disadvantage of poor control and deterioration of the quality of the molten steel. In view of this, the cost of lime is increased and the manufacturing cost of molten steel is increased.

In addition, the burnt lime in the shape of a minute or a small size injected into the converter is sucked into the dust collector together with the exhaust gas generated in the converter. The quick lime sucked into the dust collecting facility can not calculate the amount of the dust in the dust collecting facility, and therefore dust collection becomes poor and causes air pollution.

A quick lime processing apparatus and a treatment method for a lime of a converter that can prevent the introduction of small particles of quick lime into the interior of a converter by previously separating and recovering quick lime having a small particle size.

A quick lime treatment apparatus and a treatment method of a converter which can separate and recover re-use of quick lime having a small particle size.

The processing apparatus of this embodiment includes a hopper for storing a quicklime to be supplied to a converter, a screen for separating fine lime of 5 mm or less in particle size, which is provided in a charging unit for charging the quicklime of the hopper into a converter, A storage hopper which is connected to the recovery side and stores fine lime, a fine lime which is stored in the storage hopper is supplied to a nitrogen spray coating unit for internal coating of the converter, And a reprocessing unit that processes the data.

The charging unit may include a charging hopper that is connected to the screen to receive the remaining calcium oxide, and a chute for charging the calcium oxide into the charging hopper.

The nitrogen spray coating unit may include a nitrogen supply pipe connected to the lance inserted into the converter, for introducing nitrogen into the converter through the lance, and a nitrogen control valve installed in the nitrogen supply pipe.

An oxygen supply pipe connected to the lance to introduce oxygen into the passage through a lance, and an oxygen control valve installed in the oxygen supply pipe.

The reprocessing unit may include a quicklime supply pipe connecting the storage hopper and the lance to supply fine lime with the lance, and an on-off valve installed on one side of the quicklime supply pipe.

A load sensor installed in the storage hopper for detecting the amount of fine calcium oxide in the storage hopper, and a controller for controlling the supply of fine clinker by driving the open / close valve in accordance with the detected value of the load sensor.

The processing method of this embodiment includes a separation step of separating fine lime of 5 mm or less by screening the burnt lime charged in a converter, an input step of charging the remaining lime by a converter, a step of supplying the fine buried lime separated in the separation step to a storage hopper And a reprocessing step of supplying the stored fine lime to the inside of the converter together with nitrogen by supplying the lime into the ladle.

The reprocessing step may further include the step of detecting the amount of fine lime stored in the storage hopper and adjusting the amount of fine lime to be injected into the converter through the lance.

The amount of the fine lime to be injected into the converter may be more than 0 and less than 3 tons in the input amount control step.

After the reprocessing step, the step of calculating the amount of burnt lime to be charged to the converter in the charging step may be further included.

The step of calculating the quicklime charge amount may be an amount excluding the input amount of the fine flywheel charged into the converter from the set charge amount.

As described above, according to this embodiment, the recovered fine lime is charged into the converter residual liquor and reused, thereby minimizing the loss of raw materials and reducing the amount of quicklime used, thereby reducing the manufacturing cost.

In addition, it is possible to prevent the quick lime of fine powder from being injected into the converter, thereby preventing deterioration of the quality of the molten steel due to a decrease in the basicity of the molten steel.

In addition, it is possible to prevent an overload of the dust collecting apparatus for treating the converter exhaust gas, and to prevent dust collection failure and air pollution.

Fig. 1 is a schematic view showing a transfer lime treatment apparatus according to the present embodiment.
FIG. 2 is a schematic flow chart illustrating a quick lime process of a converter according to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Wherever possible, the same or similar parts are denoted using the same reference numerals in the drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified, and that other specific features, regions, integers, steps, operations, elements, components, and / And the like.

All terms including technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Fig. 1 schematically shows an apparatus for processing lime of a converter according to the present embodiment.

As shown, a lance 12 for supplying oxygen into the converter 10 is provided at an upper portion of the converter 10. The lance 12 is connected to the wire 16 wound on the driving drum 14 and moved up and down along the vertical frame 18 to and from the inside of the converter 10. [ The lance 12 is connected to an oxygen supply part for supplying refining oxygen into the converter 10 and a nitrogen injection coating part for injecting nitrogen for coating. Thus, a necessary fluid such as oxygen or nitrogen can be injected into the converter 10 through the tip of the lance 12. [

The oxygen supply unit may include an oxygen supply line 18 connected to the lance 12 to introduce oxygen into the converter 10 through the lance 12. [ A plurality of valves 19 for opening and closing the oxygen supply pipe 18 and controlling the flow rate may be installed at one side of the oxygen supply pipe 18.

The nitrogen spray coating portion may include a nitrogen supply pipe 20 connected to the lance 12 inserted into the converter 10 and introducing nitrogen into the converter 10 through the lance 12. [ A plurality of valves (21) for opening and closing the nitrogen supply pipe (20) and controlling the flow rate may be installed at one side of the nitrogen supply pipe (20).

If necessary, the oxygen supply line 18 is opened and the nitrogen supply line 20 is closed for refining, so that oxygen is injected into the converter 10 through the lance 12. During the nitrogen coating process after the refining process, the oxygen supply pipe 18 is closed and the nitrogen supply pipe 20 is opened, so that nitrogen can be injected through the lance 12.

An input unit for inputting quicklime into the converter 10 is provided at one side of the upper portion of the converter 10.

The charging unit may include a charging hopper 30 for receiving the quicklime to be charged into the converter 10 and a chute 32 for charging the quicklime to the converter 10. The quicklime accommodated in the input hopper 30 is injected into the converter 10 through the chute 32. A load sensor 34 may be installed at one side of the charging hopper 30 to detect the amount of fresh lime transferred to the charging hopper 30.

In the treatment device of this embodiment, when the quicklime is charged into the converter 10, the quicklime is separated according to the particle size, and only the quicklime of particles larger than 5 mm (hereinafter referred to as granule quicklime) is supplied to the converter 10, (Hereinafter referred to as " fine clay lime ") having a particle size of 5 mm or less is put into the residual slurry during the inside coating process of the converter 10 to absorb and reuse it.

Thus, it is possible to use the fine lime of 5 mm or less in the converter 10, and to solve the problem caused by injecting the fine lime into the converter 10.

For this purpose, the present treatment apparatus is provided with a hopper 36 for storing quicklime to be supplied to the converter 10, fine lime of a particle size of 5 mm or less installed in a charging section for charging the quicklime of the hopper 36 into the converter 10 A storage hopper 44 connected to the discharge side of the recovery bin 42 for storing fine lime, a storage hopper 44 connected to the discharge side of the recovery bin 42, And a reprocessing unit for supplying fine lime of fine particles stored in the hopper 44 to the nitrogen spray coating unit for internal coating of the converter 10 and injecting it into the converter 10 together with the coating agent.

In the screen 40, for example, a hole of a certain size capable of separating fine lime of 5 mm or less is formed, and only fine lime of 5 mm or less smaller than the hole is separated through the hole. The screen 40 may be subjected to vibrations for quicklime separation and movement. The granular quicklime remaining on the screen 40 without passing through the hole of the screen 40 is moved toward the tip of the screen 40 and is transported to the input hopper 30 of the charging unit. Therefore, only the granulated quicklime having a particle size larger than 5 mm can be accommodated in the loading hopper 30. The quicklime stored in the input hopper 30 is injected into the converter 10 through the chute 32.

A lower part of the screen 40 is provided with a recovery table 42 through which minute fine calcium oxide particles having a particle diameter of 5 mm or less are separated and passed through the screen 40. The fine flywheat collected by the recovery table 42 is transferred to the storage hopper 44 through the transfer line 45. Thus, the granular quicklime separated by the screen 40 is stored in the input hopper 30, and the fine flywheel is stored in the storage hopper 44. Therefore, only the granular quicklime can be injected into the converter 10 through the charging part, and the refining process can be performed.

The reprocessing section includes a quicklime supply pipe 46 connecting the storage hopper 44 and the lance 12 to supply fine lime and lime 12 to the lance 12 and an on-off valve 47 provided on one side of the quicklime supply pipe 46 .

Accordingly, if the on-off valve 47 is opened, the fine lime can be injected into the converter 10 through the lance 12 and reused.

Therefore, the fine lime is fed into the converter 10 and coated on the inner wall of the converter 10 together with the molten metal, so that it can be reused as a raw material for removing impurities in a later process.

The apparatus of the present embodiment is provided in the storage hopper 44 to drive the open / close valve 47 in accordance with the detected value of the load sensor 48 and the load sensor 48, which detects the amount of fine fresh lime in the storage hopper 44, And a control unit 50 for controlling the supply of the fine-grain quicklime.

The load sensor 48 detects the weight of the storage hopper 44, for example, and detects the amount of fine lime stored therein. The control unit 50 controls the opening and closing valve 47 in accordance with the amount of the particulate quicklime detected in real time from the load sensor 48 to accurately control the amount of fine lime to be charged into the converter 10. [

Hereinafter, the dust process according to the present embodiment will be described with reference to FIG.

Put scrap iron and charcoal into the converter and set up the converter and start refining.

The control unit causes the lance to descend into the interior of the converter, and when the height reaches a predetermined height, the oxygen supply pipe is opened to supply oxygen. The lance height and the oxygen flow rate can be changed according to the pattern input to the control unit.

According to the sub-raw material input pattern applied to the control unit, when the quicklime is input, the control unit transfers the quicklime stored in the hopper to the input unit. In this process, the quicklime is separated from the fine lime by the screen and only the granular quicklime is transferred to the feed hopper. The screen is vibrated according to the signal of the control unit, and the fine lime is separated and separated from the lime. The separated fine flywheat is collected and stored in the storage hopper.

Granulated quicklime not separated from the screen is transferred to the hopper and stored.

The control unit checks the detection value of the load sensor installed in the input hopper or the storage hopper and stops the supply of quicklime through the hopper when the preset amount of lime is received by the set amount.

The amount of fine lime accumulated in the storage hopper can be checked by the load sensor installed in the storage hopper. Granulated quicklime stored in the input hopper is injected into the converter through the chute. Thus, only the impregnated lime having a grain size larger than 5 mm can be supplied to the interior of the converter to perform the impurity smelting operation.

Therefore, it is possible to prevent the fine lime from being injected into the converter, thereby preventing deterioration of the quality of the molten steel due to a decrease in the basicity of the molten steel. In addition, it is possible to prevent an overload of the dust collecting apparatus for treating the converter exhaust gas.

When the refining of the converter is completed, the ladling process of moving the molten steel inside the converter to a ladle is performed. The control unit can weigh the coating agent (light dolomite, dolomite) in consideration of oxygen and the like in the molten steel.

Some of the remaining lumber that has been refinished and excavated and remains in the converter is thrown to the slag pot, and some of the lumber remains on the converter. In the state that the refining of the converter is completed, the inside of the converter has fluidity like water. After the converter is established, a nitrogen spray coating is initiated.

The lance descends according to the signal of the control unit, and when the height reaches a certain height, the nitrogen supply pipe is opened, and high pressure nitrogen is injected into the interior of the converter while maintaining the set flow rate and lance height.

At this time, the coating agent is injected, and the slag and the coating agent are tangled and attached to the inner refractory material. At the fitted flow rate, the control raises the lance and blocks the nitrogen supply to complete the nitrogen spray coating operation. After the nitrogen spray coating process is completed, the converter is moved back and forth to attach the remaining material to the converter refractory. When the nitrogen injection is completed, the molten material sticks to the coating agent and becomes sticky and adheres well to the converter refractory.

In the nitrogen spray coating process, the control unit supplies fine lime with a lance, and feeds the lime together with nitrogen into the internal furnace.

When the lance is inserted into the inside of the converter, the control unit opens the opening / closing valve of the quicklime supply pipe together with the nitrogen supply, and supplies the fine lime to the lance.

 High pressure nitrogen of about 25 bar is injected into the upper part of the column through the lance and the fine lime in the storage hopper is sucked in the direction of high pressure nitrogen flow by Bernoulli principle. Thus, the fine lime is put into the furnace inside the converter together with nitrogen.

Particulate lime which is sucked into the liquefied lime with high pressure nitrogen is absorbed into the lumber without being absorbed by the dust collecting facility when it reaches the upper part of the liquefied material.

The load sensor provided in the storage hopper continuously detects the amount of fine quicklime discharged from the storage hopper. The control unit calculates the detected value, and when the amount of the quicklime discharged reaches the predetermined fine lime loading amount, the control unit closes the opening / closing valve to stop discharging the fine lime. For example, when the amount of fine lime is set to 1 ton, when the amount of fine lime discharged from the load sensor reaches 1 ton, the control unit can close the opening / closing valve.

In this embodiment, the amount of fine lime inserted into the converter in the nitrogen spray coating process may be more than 0 and less than 3 tons. If the amount of the fine lime is more than 3 ton, the lumber does not absorb the fine lime and the physical properties are deteriorated and the inner wall coating of the converter is not properly performed.

After the nitrogen spray coating is completed, the converter is turned back and forth to protect the converter refractory. As described above, the fine-buried quicklime separated and recovered can be put into the residual converter material for absorption and reused.

When the injection of the fine lime is finished and the coating operation is completed, the controller calculates the amount of quicklime to be supplied to the converter in the next process. Calcination of the quicklime input amount can be set by excluding the amount of the quicklime introduced into the converter from the set quicklime amount.

That is, when the silicon in the molten iron is identified and the calcium oxide input value is calculated, the control unit can subtract the fine calcium oxide added during the nitrogen spray coating operation. For example, if one ton of fine quicklime is supplied from a storage hopper, the mixture is injected into the converter through a nitrogen spray coating process, and if the amount of quicklime set in the next step is 8.5 tons, the amount of quicklime to be supplied to the actual converter is 7.5 tons Can be calculated.

As described above, in this embodiment, the fine lime is recovered and reused in the converter, whereby the loss of the raw material can be minimized and the amount of quicklime used can be reduced.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

10: Converter 12: Lance
18: oxygen supply pipe 19, 21: valve
20: Nitrogen feed pipe 30: Feed hopper
32: Suit 34,48: Load sensor
36: hopper 40: screen
42: Recycle bin 44: Storage hopper
45: transfer line 46: quicklime supply pipe
47: ON / OFF valve 50:

Claims (11)

A hopper in which quicklime to be supplied to the converter is stored,
A screen which is provided at a charging part for charging the quick lime of the hopper into a passage and separates the fine lime of 5 mm or less in particle size,
A recovery table installed at a lower portion of the screen to receive separated fine quicklime,
A storage hopper which is connected to the recovery / discharge side for storing fine lime;
A reprocessing unit for supplying fine rocks stored in the storage hopper to a nitrogen spray coating unit for internal coating of the converter,
Wherein the apparatus comprises: The method according to claim 1,
Wherein the charging unit comprises a charging hopper which is connected to the screen and is separated and receives the remaining quicklime, and a chute installed in the charging hopper for charging the quicklime into the electric circuit. The method according to claim 1,
Wherein the nitrogen spray coating portion includes a nitrogen supply pipe connected to a lance inserted into a converter and introducing nitrogen into the converter through a lance, and a nitrogen control valve installed in the nitrogen supply pipe. The method of claim 3,
An oxygen supply pipe connected to the lance for introducing oxygen into the passage through a lance, and an oxygen control valve installed in the oxygen supply pipe. 5. The method according to any one of claims 1 to 4,
Wherein the reprocessing unit includes a quicklime supply pipe connecting the storage hopper and the lance to supply the fine lime with the lance, and an on-off valve installed on one side of the quicklime supply pipe. 6. The method of claim 5,
A load sensor installed in the storage hopper for detecting the amount of fine calcium oxide in the storage hopper, and a control unit for driving the open / close valve in accordance with the detected value of the load sensor to control supply of fine lime. . A separation step of screening the quick lime charged into the converter to separate fine lime of 5 mm or less,
A feeding step of feeding the fresh lime separated and left to the converter,
Storing the fine flywheat separated in the separation step in a storage hopper, and
Reprocessing step in which the stored fine lime is fed into the lance and injected into the converter together with nitrogen during the converter inner coating process
Wherein the method comprises the steps of: 8. The method of claim 7,
Wherein the reprocessing step further comprises the step of detecting the amount of fine lime accumulated in the storage hopper and adjusting the amount of fine lime to be introduced into the converter through the lance. 9. The method of claim 8,
Wherein the amount of the fine quicklime introduced into the converter in the input amount controlling step is less than 3 tons. 9. The method of claim 8,
Further comprising, after the reprocessing step, calculating an input amount of quicklime to be supplied to the converter in the charging step. 11. The method of claim 10,
Wherein the step of calculating the input amount of quicklime is calculated by subtracting the amount of fine lime inserted into the converter from the set amount of input.

Images