A method and device for eliminating the mixing and overflowing of hot molten desulphurization slag and converter slag in a ladle

Abstract

A method and device for eliminating overflow of hot molten iron desulfurization slag and converter slag in a tank, the hot molten iron desulfurization slag and the hot converter slag are preliminarily mixed and reacted in a large-area thin slag layer expansion space scale, so that the CO gas generated by the mixed and reacted hot molten iron desulfurization slag and the converter slag can overflow freely and smoothly, and then enter the mixed slag tank for sufficient reaction, avoiding the rapid and concentrated CO explosion caused by the direct mixing of the hot molten iron desulfurization slag and the converter slag in the mixed slag tank, and avoiding the overflow or spatter caused by the rapid and concentrated CO explosion, so that the mixed and reacted hot molten iron desulfurization slag and the converter slag can be more smoothly implemented on site, the hot molten iron desulfurization slag and the converter slag are modified under the hot state, the metal iron in the slag is fully recovered and returned to the main process of steel and iron, the remaining tailings are used for roads, building materials or other application occasions, and the hot molten iron desulfurization slag and the converter slag are resourcefully utilized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel slag treatment, in particular to a method and device for eliminating overflow of mixed molten hot-state molten iron desulfurization slag and converter slag in a tank. BACKGROUND

[0002] In order to produce high-value-added fine steel, molten iron pretreatment technology is widely used in steel enterprises. A large amount of molten iron desulfurization slag is generated by large-scale molten iron desulfurization pretreatment, which needs to be treated. The current molten iron desulfurization slag treatment process is water immersion process. In this process, slag and iron are easily formed into a large lump in the slag tank. In order to solve the problem of molten iron desulfurization slag lumping, a mixed melting modification technology of hot-state molten iron desulfurization slag and hot-state converter slag can be developed. Through modification, the molten iron desulfurization slag is converted into steel slag, and then the mature steel slag treatment process is used for post-treatment.

[0003] Generally, the mixed melting of hot-state molten iron desulfurization slag and hot-state converter slag is directly mixed by pouring one slag liquid into another slag liquid. However, since the molten iron desulfurization slag is a reducing slag and the converter slag is an oxidizing slag, the composition characteristics of the two slags vary greatly under different production conditions. Therefore, when the two slags are mixed in the tank, the rapid melting and concentration of the two slags in the mixing tank will generate a large amount of CO, which will cause the slag surface to rise rapidly and overflow.

[0004] Chinese patent CN102443671A discloses a method for controlling the rise of the slag surface in the ladle after converter tapping. According to the different [C] content at the end of converter blowing, the appropriate amount of aluminum deoxidizer and its addition time are configured to solve the problem of the rise of the slag surface in the ladle after converter tapping, thereby eliminating the phenomenon of ladle slag overflow. It belongs to the field of steelmaking process and solves the problem of overflow of refining slag, but does not involve the overflow caused by the mixed melting of hot-state molten iron desulfurization slag and hot-state converter slag.

[0005] At present, research and development on the mixed melting of molten iron desulfurization slag and converter slag under hot-state conditions and the modification of molten iron desulfurization slag have just begun. Therefore, there is no report on how to solve the overflow phenomenon caused by the mixed melting of hot-state molten iron desulfurization slag and hot-state converter slag. Therefore, how to effectively improve the overflow phenomenon of hot-state molten iron desulfurization slag and hot-state converter slag mixed melting and improve the modification effect is an urgent problem to be solved. SUMMARY

[0006] The present application aims to provide a method and device for eliminating overflow of hot molten iron desulfurization slag and converter slag in a tank, realizing modification of the molten iron desulfurization slag and converter slag in hot state, preventing the molten iron desulfurization slag and converter slag in hot state from overflowing due to rapid and concentrated generation of CO gas, thus eliminating the safety problem of overflow or spatter of the hot molten iron desulfurization slag and converter slag, and making the two-slag mixing method more smoothly implemented on site.

[0007] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0008] A method for eliminating overflow of hot molten iron desulfurization slag and converter slag in a tank, comprising the following steps:

[0009] 1) Preparation

[0010] Setting a desulfurization slag chute, a converter slag chute, and a mixed slag tank for mixing reaction of hot molten iron desulfurization slag and hot converter slag;

[0011] 2) Mixing

[0012] The hot molten iron desulfurization slag enters the converter slag chute through the desulfurization slag chute, mixes with the hot converter slag poured into the converter slag chute, and performs a preliminary reaction, and then falls into the mixed slag tank along the converter slag chute to perform a full reaction;

[0013] Alternatively, the hot converter slag enters the desulfurization slag chute through the converter slag chute, mixes with the hot molten iron desulfurization slag poured into the desulfurization slag chute, and performs a preliminary reaction, and then falls into the mixed slag tank along the desulfurization slag chute to perform a full reaction;

[0014] Alternatively, the hot molten iron desulfurization slag flows out through the desulfurization slag chute, the hot converter slag flows out through the converter slag chute, and then mixes at the outlet ends of the desulfurization slag chute and the converter slag chute, performs a preliminary reaction, and then falls into the mixed slag tank to perform a full reaction;

[0015] 3) Post-processing

[0016] After the hot molten iron desulfurization slag and the hot converter slag in the mixed slag tank are fully reacted, the mixed slag is subjected to subsequent processing according to a converter slag processing process.

[0017] Further, in step 2), the mixed slag after the preliminary reaction enters an intermediate reaction container for further reaction, and then falls into the mixed slag tank for full reaction.

[0018] Further, in step 2), the CO gas and smoke generated during the reaction of the hot molten iron desulfurization slag and the hot converter slag are sucked through a dust hood and discharged after treatment.

[0019] Preferably, in step 3), the converter slag processing process is a hot splashing process, a roller process, or a hot stewing process.

[0020] The application also provides a device for the method of eliminating overflow of hot molten iron desulfurization slag and converter slag in a tank, comprising:

[0021] A mixed slag tank;

[0022] A desulfurization slag chute and a converter slag chute are arranged above the mixed slag tank; a chute adjusting device for adjusting the height and inclination angle of the chute is arranged below the desulfurization slag chute and the converter slag chute respectively; preferably, the surface of the desulfurization slag chute, the surface of the converter slag chute and the inner wall of the mixed slag tank are coated with a temperature-resistant protective layer.

[0023] Further, a mixing funnel is arranged above the mixed slag tank, and the inner wall of the mixing funnel is coated with a temperature-resistant protective layer; preferably, the width of the outlet end of the desulfurization slag chute and / or the converter slag chute is 20-90% of the diameter of the inlet of the mixing funnel, the diameter of the outlet of the mixing funnel is 20-90% of the diameter of the tank mouth of the mixed slag tank, and the deviation degree of the center line of the chute outlet, the center line of the mixing funnel and the center line of the mixed slag tank is less than 5%.

[0024] Preferably, the width of the outlet end of the desulfurization slag chute and / or the converter slag chute is 20-90%, preferably 60-80%, of the diameter of the tank mouth of the mixed slag tank, and the deviation degree of the center line of the chute outlet and the center line of the mixed slag tank is less than 5%.

[0025] Preferably, the desulfurization slag chute and the converter slag chute and their chute adjusting devices are arranged on two oppositely arranged platforms respectively.

[0026] Preferably, a slag tank tilting device and / or a crane are arranged on the platforms respectively.

[0027] Preferably, dust hoods are arranged above the desulfurization slag chute and the converter slag chute.

[0028] The existing hot molten iron desulfurization slag and hot converter slag are directly mixed in a slag tank. After the hot molten iron desulfurization slag and the hot converter slag are directly mixed, the generated CO gas is not easy to be discharged due to the constraint of the longitudinal depth and volume of the slag tank.

[0029] In the application, the hot molten iron desulfurization slag and the hot converter slag are preliminarily mixed in a large-area thin slag layer expansion space before they enter the mixed slag tank for mixing, so that the CO gas generated by the mixing reaction of the hot molten iron desulfurization slag and the converter slag can be smoothly overflowed. After the mixed slag after the preliminary reaction enters the mixed slag tank, since most of the reaction is completed in the preliminary reaction, the secondary mixing reaction is relatively mild and will not generate too much CO gas, so that the rising and overflowing of the slag surface in the mixed slag tank will not be caused, thereby eliminating the risk of overflow or spatter of the hot molten iron desulfurization slag and the converter slag directly mixed in the slag tank.

[0030] The desulfurization slag chute and the converter slag chute are respectively used for receiving the hot molten desulfurization slag poured from the desulfurization slag tank and the hot converter slag poured from the converter slag tank, so that the molten desulfurization slag and the converter slag flowing out of the chutes form a large-area thin-layer shallow-pool liquid-liquid mixture in the desulfurization slag chute or the converter slag chute or at the outlets of the two chutes. Since the static pressure exerted by the thickness of the slag pool is very small, the distance affected by the viscous force of the gas overflowing in the thickness direction of the slag pool is also small, and there is no constraint of the four surrounding container walls in the tank, the generated CO gas can more easily overflow from the slag layer.

[0031] The preliminarily reacted molten desulfurization slag and the converter slag enter the mixed slag tank for full mixing and complete the remaining mixed melting reaction. Since most of the reaction is completed in the preliminary reaction, the full mixing reaction is relatively mild and will not produce too much CO gas, avoiding the CO explosion caused by the direct mixing of the molten desulfurization slag and the converter slag in the mixed slag tank, which can effectively promote the hot modification of the molten desulfurization slag, and make the mixed melting of the hot molten desulfurization slag and the hot converter slag more smoothly implemented on site and achieve good treatment effect.

[0032] As preferred, before the molten desulfurization slag and the converter slag enter the mixed slag tank, they can first enter the intermediate reaction container for reaction, so that the reaction of the molten desulfurization slag and the converter slag is more sufficient, and the amount of CO gas generated when the molten desulfurization slag and the converter slag enter the mixed slag tank is further reduced.

[0033] The CO gas and the smoke dust generated by the mixed melting of the molten desulfurization slag and the converter slag are sucked by the dust removal cover, and after treatment, they are discharged up to the standard, which can reduce the pollution to the environment.

[0034] The present application realizes the collision of the flow of the molten desulfurization slag and the converter slag near the outlet end of the converter slag chute or the desulfurization slag chute or the two chutes by adjusting the position of the outlet end of the two chutes, the molten desulfurization slag and the converter slag intersect and mix for preliminary reaction, and the reducing elements such as [C], [Si], [Mn], and [P] in the molten desulfurization slag react with the oxidizing components such as (FeO) and (MnO) in the converter slag. Because the reaction occurs in a free space, the CO gas generated by the reaction can freely escape without constraint.

[0035] The position of the mixed molten slag falling into the mixed slag tank is as close as possible to the center of the tank opening, i.e. near the diameter of the tank opening. When the mixed slag flows out of the outlet end of the chute, into the mixing hopper and the mixed slag tank, the deviation degree of the center line of the mixed slag flowing end, the mixing hopper and the mixed slag tank is kept as small as possible, i.e. less than 5%, to avoid the mixed molten slag flowing out of the mixed slag tank.

[0036] The volume of the mixed slag tank is usually much larger than the sum of the volume of the hot metal desulfurization slag and the volume of the converter slag after the hot metal desulfurization slag and the converter slag are mixed.

[0037] The present application has the following advantages:

[0038] The present application avoids directly mixing the hot metal desulfurization slag and the hot converter slag in the slag tank. The hot metal desulfurization slag and the hot converter slag are first mixed in a large-area thin slag layer to perform a preliminary reaction, so that the CO gas generated by the mixing reaction of the hot metal desulfurization slag and the converter slag can overflow freely and smoothly. Then, the remaining reaction is performed in the mixed slag tank. Since most of the reaction is completed in the preliminary reaction, the sufficient reaction in the mixed slag tank is relatively mild and does not generate too much CO gas. The rapid and concentrated generation of CO gas caused by the direct mixing of the hot metal desulfurization slag and the converter slag in the mixed slag tank is avoided, and the overflow or spatter of the slag is avoided. The hot modification of the hot metal desulfurization slag and the converter slag can be effectively promoted, the mixing of the hot metal desulfurization slag and the converter slag can be more smoothly implemented on site, and good treatment effect can be achieved.

[0039] After the mixed slag obtained by mixing the hot metal desulfurization slag and the hot converter slag is treated according to the converter slag treatment process, such as the hot splashing process, the roller process or the hot stewing process, the metal iron in the slag is fully recovered and returned to the main steel process, and the remaining tailings are used for roads, building materials or other applications. The hot metal desulfurization slag and the converter slag are resourceized, the cost of steelmaking is reduced, and the improvement of economic and social benefits such as energy and environment is also brought about. BRIEF DESCRIPTION OF DRAWINGS

[0040] Fig. 1 The device for eliminating the overflow of the hot metal desulfurization slag and the converter slag in the tank is shown in the device schematic diagram of the hot metal desulfurization slag and the converter slag in the tank.

[0041] Fig. 2 The device for eliminating the overflow of the hot metal desulfurization slag and the converter slag in the tank is shown in the device schematic diagram of the hot metal desulfurization slag and the converter slag in the tank.

[0042] Fig. 3 The device for eliminating the overflow of the hot metal desulfurization slag and the converter slag in the tank is shown in the device schematic diagram of the hot metal desulfurization slag and the converter slag in the tank. DETAILED DESCRIPTION

[0043] The present application will be further described below in conjunction with the embodiments and the drawings.

[0044] Reference Figs. 1-3 The device for eliminating the overflow of the hot metal desulfurization slag and the converter slag in the tank is shown in the device schematic diagram of the hot metal desulfurization slag and the converter slag in the tank.

[0045] The mixed slag tank 1;

[0046] Desulfurization slag chute 2, converter slag chute 3, set in the mixed slag tank 1 above; the desulfurization slag chute 2, converter slag chute 3 below are respectively set for adjusting the height and inclination angle of the chute chute adjusting device 4, 4'; preferably, the desulfurization slag chute surface, converter slag chute surface and mixed slag tank inner wall are coated with a temperature-resistant protective layer.

[0047] Further, a mixing funnel 5 is provided above the mixed slag tank, and the inner wall of the mixing funnel is coated with a temperature-resistant protective layer; preferably, the width of the desulfurization slag chute and / or the outlet end of the converter slag chute is 20-90% of the diameter of the inlet of the mixing funnel, the outlet diameter of the mixing funnel is 20-90% of the diameter of the tank mouth of the mixed slag tank, and the deviation degree of the center line of the chute outlet, the center line of the mixing funnel and the center line of the mixed slag tank is less than 5%.

[0048] Preferably, the width of the desulfurization slag chute and / or the outlet end of the converter slag chute is 20-90% of the diameter of the tank mouth of the mixed slag tank, preferably 60-80%, and the deviation degree of the center line of the chute outlet and the center line of the mixed slag tank is less than 5%.

[0049] Preferably, the desulfurization slag chute 2 and the converter slag chute 3 and the chute adjusting device 4, 4' below them are respectively arranged on two oppositely arranged platforms 6, 6'.

[0050] Preferably, the platform 6, 6' is respectively provided with a slag tank tilting device 7, 7' and / or a crane 8, 8'.

[0051] Preferably, dust hoods 9 are provided above the desulfurization slag chute and the converter slag chute.

[0052] Example 1

[0053] Referring to Fig. 1 The method for eliminating hot molten desulfurization slag and converter slag mixed in the tank and overflowing slag according to the present application comprises the following steps:

[0054] 1) Preparation

[0055] Desulfurization slag chute 2 and converter slag chute 3 and hot molten desulfurization slag and hot converter slag mixed reaction mixed slag tank 1 are set;

[0056] 2) Mixing

[0057] The height and the inclination angle of the desulfurization slag chute 2 and the converter slag chute 3 are adjusted by the chute adjusting device 4, 4', the outlet ends of the desulfurization slag chute 2 and the converter slag chute 3 are arranged in parallel, and the distance between the outlet ends of the desulfurization slag chute 2 and the converter slag chute 3 should meet the requirement that the molten slag flowing out of the two chutes can be mixed and melted at the outlet ends; the desulfurization slag tank 11 containing hot-state molten iron desulfurization slag and the converter slag tank 12 containing hot-state converter slag are transported by the travelling crane 10, and then the desulfurization slag tank 11 and the converter slag tank 12 are respectively tilted by the cranes 8, 8', so that the hot-state molten iron desulfurization slag flows out through the desulfurization slag chute 2, the hot-state converter slag flows out through the converter slag chute 3, and then the hot-state molten iron desulfurization slag and the hot-state converter slag are mixed by the slag flow collision at the outlet ends of the desulfurization slag chute and the converter slag chute, the convection mixing under the hot-state condition occurs, the preliminary reaction is carried out, and then the mixed slag tank 1 is filled for full reaction; the CO gas is absorbed by the dust hood 9 above;

[0058] 3) Post-processing

[0059] After the hot-state molten iron desulfurization slag and the hot-state converter slag are fully reacted, the mixed slag tank is transported to the converter slag processing field by the travelling crane 10, and the mixed slag is subjected to subsequent processing according to the converter slag processing process.

[0060] Example 2

[0061] Referring to Fig. 2 The method for eliminating the mixed slag overflow of the hot-state molten iron desulfurization slag and the converter slag in the tank, provided by the application, comprises the following steps:

[0062] 1) Preparation

[0063] The desulfurization slag chute 2 and the converter slag chute 3 and the mixed slag tank 1 for the mixed reaction of the hot-state molten iron desulfurization slag and the hot-state converter slag are arranged;

[0064] 2) Mixing and melting

[0065] The height and the inclination angle of the desulfurization slag chute 2 and the converter slag chute 3 are adjusted through the chute adjusting device 4, 4', the outlet ends of the desulfurization slag chute 2 and the converter slag chute 3 are arranged in parallel, and the distance between the outlet ends of the desulfurization slag chute 2 and the converter slag chute 3 should meet the requirement that the molten slag flowing out of the two chutes can be mixed and melted at the outlet ends; the desulfurization slag tank 11 containing hot-state molten iron desulfurization slag and the converter slag tank 12 containing hot-state converter slag are transported by the travelling crane 10, and then the desulfurization slag tank 11 and the converter slag tank 12 are respectively tilted by the slag tank tilting device 7, 7', so that the hot-state molten iron desulfurization slag flows out through the desulfurization slag chute 2, the hot-state converter slag flows out through the converter slag chute 3, and then the hot-state molten iron desulfurization slag and the hot-state converter slag are mixed by the slag flow collision at the outlet ends of the desulfurization slag chute and the converter slag chute, the hot-state molten iron desulfurization slag and the hot-state converter slag are mixed and melted by convection, preliminary reaction is carried out, then the hot-state molten iron desulfurization slag and the hot-state converter slag further react in the mixing hopper 5, and finally the hot-state molten iron desulfurization slag and the hot-state converter slag fully react in the mixed slag tank 1; the generated CO gas is sucked through the dust hood 9 above;

[0066] 3) Post-processing

[0067] After the hot-state molten iron desulfurization slag and the hot-state converter slag are fully reacted, the mixed slag tank is transported to the converter slag processing field by the travelling crane 10, and the mixed slag is subjected to subsequent processing according to the converter slag processing process.

[0068] Example 3

[0069] Referring to Fig. 3 , the method for eliminating the mixed melting overflow of hot-state molten iron desulfurization slag and converter slag in a tank provided by the application comprises the following steps:

[0070] 1) Preparation

[0071] The desulfurization slag chute 2 and the converter slag chute 3 and the mixed slag tank 1 for the mixed reaction of the hot-state molten iron desulfurization slag and the hot-state converter slag are arranged;

[0072] 2) Mixed melting

[0073] The height and the inclination angle of the desulfurization slag chute 2 and the converter slag chute 3 are adjusted through the chute adjusting device 4, 4', the outlet end of the converter slag chute 3 is located above the desulfurization slag chute 2; the desulfurization slag tank 11 containing hot-state molten iron desulfurization slag and the converter slag tank 12 containing hot-state converter slag are transported by the travelling crane 10, then the desulfurization slag tank 11 is tilted by the slag tank tilting device 7, the converter slag tank 12 is tilted by the travelling crane 10, the hot-state converter slag enters the desulfurization slag chute 2 through the converter slag chute 3 and mixes with the hot-state molten iron desulfurization slag in the desulfurization slag chute 2, preliminary reaction is carried out, then the hot-state molten iron desulfurization slag and the hot-state converter slag fall into the mixed slag tank 1 along the desulfurization slag chute 2 and fully react; the generated CO gas is sucked through the dust hood 9 above;

[0074] 3) Post-processing

[0075] After the reaction of the hot molten iron desulfurization slag and the hot converter slag is completed, the mixed slag tank is transferred to the converter slag treatment field by the travelling crane 10, and the mixed slag is subjected to subsequent treatment according to the converter slag treatment process.

Claims

1. A method for eliminating the mixing and overflowing of hot liquid iron desulphurization slag and converter slag in a ladle, characterized in that, The method comprises the following steps: 1) Preparation of the operation Setting a desulfurization slag chute, a converter slag chute, and a mixed slag tank for the mixing reaction of hot desulfurization slag and hot converter slag; 2) Melting The hot desulfurization slag is mixed with the hot converter slag poured into the converter slag chute through the desulfurization slag chute, and the preliminary reaction is carried out, and then the mixed slag falls into the mixed slag tank through the converter slag chute to carry out the full reaction; Or, the hot converter slag is mixed with the hot desulfurization slag poured into the desulfurization slag chute through the converter slag chute, and the preliminary reaction is carried out, and then the mixed slag falls into the mixed slag tank through the desulfurization slag chute to carry out the full reaction; Or, the hot desulfurization slag flows out through the desulfurization slag chute, and the hot converter slag flows out through the converter slag chute, and then the mixed slag falls into the mixed slag tank after the preliminary reaction of the mixed slag at the outlet end of the desulfurization slag chute and the converter slag chute. 3) Post-treatment After the hot desulfurization slag and the hot converter slag are fully reacted in the mixed slag tank, the mixed slag is subjected to subsequent treatment according to the converter slag treatment process.

2. The method according to claim 1, wherein the molten slag of the hot molten iron desulphurization and the molten slag of the converter are mixed and overflowed in the tank. In step 2), the mixed slag after the preliminary reaction is further reacted in the intermediate reaction container and then falls into the mixed slag tank to carry out the full reaction.

3. The method of claim 1, wherein the molten slag of the hot state of the molten iron and the molten slag of the converter are mixed and overflowed in the tank. In step 2), the CO gas and the smoke dust generated in the reaction process of the hot desulfurization slag and the hot converter slag are sucked through the dust removal cover, and are discharged after treatment.

4. The method of claim 1, wherein the molten slag of the hot state of the molten iron and the molten slag of the converter are mixed and overflowed in the tank. In step 3), the converter slag treatment process is a hot splashing process, a roller process or a hot stewing process.

5. A device for the method of eliminating the mixing and overflowing of hot liquid iron desulphurization slag and converter slag in a tank as claimed in claim 1, characterized in that, It comprises: a mixed slag tank; a desulfurization slag chute and a converter slag chute arranged above the mixed slag tank; the desulfurization slag chute and the converter slag chute are respectively provided with chute adjusting devices for adjusting the height and the inclination angle of the chute.

6. The apparatus of claim 5, wherein, The surface of the desulfurization slag chute, the surface of the converter slag chute and the inner wall of the mixed slag tank are coated with a temperature-resistant protective layer.

7. The apparatus of claim 5, wherein, A mixing funnel is arranged above the mixed slag tank, and the inner wall of the mixing funnel is coated with a temperature-resistant protective layer.

8. The apparatus of claim 7, wherein, The outlet end width of the desulfurization slag chute and / or the converter slag chute is 20-90% of the diameter of the inlet of the mixing funnel, the outlet diameter of the mixing funnel is 20-90% of the diameter of the tank mouth of the mixed slag tank, and the deviation degree of the outlet center line of the desulfurization slag chute and / or the converter slag chute, the center line of the mixing funnel and the center line of the mixed slag tank is less than 5%.

9. The apparatus of claim 5, wherein, The outlet end width of the desulfurization slag chute and / or the converter slag chute is 20-90% of the diameter of the tank mouth of the mixed slag tank, and the deviation degree of the outlet center line of the desulfurization slag chute and / or the converter slag chute and the center line of the mixed slag tank is less than 5%.

10. The apparatus of claim 9, wherein, The outlet end width of the desulfurization slag chute and / or the converter slag chute is 60-80% of the diameter of the tank mouth of the mixed slag tank.

11. The apparatus of claim 5, wherein, The chute adjusting devices for adjusting the height and the inclination angle of the desulfurization slag chute and the chute adjusting devices for adjusting the height and the inclination angle of the converter slag chute are respectively arranged on two oppositely arranged platforms.

12. The apparatus of claim 11, wherein, A slag tank tilting device and / or a crane are arranged on the platforms.

13. The apparatus of claim 5 or 11, wherein, A dust removal cover is arranged above the desulfurization slag chute and the converter slag chute.

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