JPS6183877A - Method of treating steel-making dephosphorized slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to converter slag, ingot slag (
These are collectively referred to as temperature control slag) and the dephosphorization slag (hereinafter referred to as dephosphorization slag) produced in the dephosphorization treatment process, which is the pretreatment process for pig iron.
-Seki JzuJ Monogoa・-0 [Prior art] Generally, steelmaking slag and dephosphorous slag are made of 2Ca(L SiO
□F CaO, F 1gO, 2CaO, Fails
, 4CaO・^1z(h Fc+rO+, FeO,
Mainly contains FeJz, FeJt, etc., so 2C
During the cooling process, aO・SiO□ becomes r2CaO5iOz
Expansion collapse occurs due to volume expansion when F CaO, F -Mgo absorbs water and changes to Ca(OH)z, -g (011) t. For this reason,
Cement raw materials (CaO, 5iOz, FetOx
ill), used as fertilizer or 1, Si
n,,^It's, Adding a modifying material containing an appropriate amount of FeJs to the molten slag (refers to steelmaking slag in a molten state) modifies the slag into a stabilized product that does not expand and collapse, and can be used as a roadbed material. Most of the power used for this purpose was disposed of in landfills and was not fully utilized as a resource.

Therefore, efforts are being made to recycle steelmaking slag and dephosphorized slag as resources.
Contains Jr, FeO, Fe1O4, MgO, MnO and has a fufunox effect (: IA 4.'j IKF
There are some studies on its use as l.

However, as steelmaking slag and dephosphorized slag contain a large amount of phosphorus (hereinafter referred to as P), when used in silent furnace coatings, the P is reduced and the P content in the hot metal becomes high. l! l
There is a problem in that a large amount of CaO must be used to remove P in the process, and it is convenient to use it as a raw material for steelmaking because it turns into slag quickly, but this type of steel has the problem of high P content during steelmaking. As a research, red mud, slate alone or a mixture, and chloride were added to molten steel slag, which was described in Japanese Patent Publication No. 1984-484, which the applicant had previously researched and filed, and volatilized it. There is a method for dephosphorizing steel slag that involves sucking gas into water.

[Problem that the invention seeks to solve]

The method for dephosphorizing steel slag described in the above-mentioned Japanese Patent Publication No. 56-48.1 has made it possible to reduce the P content in steel slag, which is the problem mentioned above.
In order to obtain the above-mentioned raw materials by occupying the Ut as the IIQ l'Snope Association, it is necessary to crush the solidified steelmaking slag and dephosphorized slag using a machine such as Kuranoya and perform magnetic separation. , and its uses were also limited.

Furthermore, the method for dephosphorizing steel slag described above targets IJ steel slag melted in a high-temperature submerged plate, and uses its sensible heat to dephosphorize.
Therefore, if the slag contained partially solidified slag in a low temperature state, it was not possible to remove P sufficiently.

The present invention was made in view of the above circumstances, and includes not only high-temperature deaf steelmaking slag and dephosphorized slag (collectively referred to as slag), but also partially solidified net-making slag and dephosphorized slag. By reforming and dephosphorizing the slag, we will be able to utilize it more widely as a resource for steelmaking slag and dephosphorous slag, instead of crushing and magnetic separation using machines such as Kuranoya, which was conventionally done. The present invention provides a method for treating steelmaking slag and P-free slag.

[Means to solve problems]

In accordance with the above purpose; Jl! ! Button, 1 snok,
111!゛The slag treatment method is to add 3 to 10% by weight to the molten converter, agglomerate or demolition/slag containing the slag that has been discharged from the converter or SI4 to SI4 and has been partially smelted.
The first step is to add a melting point viscosity reducing material and 3 to 5% by weight of chloride, and the converter, agglomeration or dephosphorization slag to which the above additives have been added is melted using an auxiliary heat source generator in a processing furnace. a second step in which the phosphorus contained in the slag is volatilized and the metal in the slag is settled to the lower part; - the slag which has been subjected to pAI by the amount of the metal is taken out from the treatment furnace; It consists of a third step in which the water slag is used as a resource, and a fourth step in which the metal settled at the bottom of the processing furnace is taken out after a certain amount of water and used as metal waste.

Here, the melting point viscosity reducing material in the first two culms is 5i02,
8120), FezOt, refers to something containing an appropriate amount of NazO, and in terms of length, it includes red mud, silicate rocks, silicate minerals, kitites, s) #material sand, blast furnace slag, Coal ash, glass scraps, silica, dust or iron oxide
1st small, l- is 411i 1'l l is 11J, also υ
all).

The total height, viscosity, low F material and chloride addition method are as follows:
(a) Pour into the smelting furnace from the beginning or middle of smelting (
h) Inject into the smelting furnace after tapping (c) Inject in contact with the slag (molten slag) discharged from the smelting furnace and ladle (d)
) The slag flow is thrown into the slag ladle from the smelting furnace and ladle into the slag ladle at a distance from the falling position. (e) It is used as a substitute for slag in the slag ladle. (r) (11 Pour the slag into the ladle in the form of ?81 and slag (g> if! Pour into the ladle after casting is complete. (h) Pour into the pot or ladle before scraping out the dephosphorous slag. (1) Inject the dephosphorized slag in contact with the slag method when scraping it out (j) Inject the molten slag into a processing furnace equipped with an auxiliary heat source generator used in the second process (as mentioned above, some of the molten slag is (k) (j)
Add the i8M slug using the method described above. (1)(
After adding 7'a molten slag using method j), add it while operating the processing furnace (-) After adding using methods (c) to (1) above, insert a lance pipe-like object and 0□ , N2. Or blow in the finish (, Hanori 7' Riwo I1) 1/I,
■,・.

In addition, the auxiliary heat source generator refers to a device that generates force for melting the molten slag in the processing furnace, and includes, for example, a lance-shaped burner or tuyere burner that blows out oxygen gas and liquid fuel or gaseous fuel. An electric furnace that is attached to a furnace lid and consists of a burner that blows out oxygen gas and liquid or gaseous fuel, or an electric furnace that generates heat using electric power.

Also, to be used as rttA in the third step,
For example, 111 is used for sintering raw materials, steelmaking auxiliary raw materials, roadbed materials, sludge hardening materials, cement admixtures, briquettes, banhgu during pellet production, sand, etc.Using as resources in the 4th process means, for example , to be returned to the steelmaking furnace in a hot charger, or turned into ingots in a steel casting machine and used as an iron source.

[Effect]

First, in the first step, 3/8 molten converter slag, agglomeration slag, or dephosphorization slag containing molten or partially solidified slag discharged from a converter or ladle is added to
The reason for adding ~10% by weight of the melting point viscosity reducing agent will be explained. HaJ slag has a high basicity, so its melting point (?
The temperature (1520-1545°C) is high, and the viscosity is low when the temperature is 1°C. However, the temperature of steelmaking slag is 1500~
At 1530°C, 2CaO.SiO□ crystallizes rapidly and the viscosity becomes 100 poise or more, so a melting point viscosity reducing agent was added. As this melting point viscosity reducing material, SiO□, ^180°it' (Germany or 5i02
~ AI tOs-based refractory brick crushed material may also be used, but it has the disadvantage that the melting temperature is high (and the reaction is difficult to occur).
S i (lz, 8IzO1, Fe, Ox, Na, 0
Add something containing an appropriate amount of. This melting point viscosity reducing material also acts as a slag modifier, and by adding the melting point viscosity reducing material, the slag after treatment is prevented from expanding and collapsing.

In addition to this melting point viscosity reducing material, steelmaking slag, 1118
Chloride is added to volatilize P in the P slag.

Next, in the second step, the steelmaking slag and dephosphorization slag to which the above additives have been added are completely melted in a processing furnace equipped with an auxiliary heat source generator. As a result, the slag that has been partially assimilated is also dissolved, and the viscosity is also reduced due to the above-mentioned lower melting point viscosity and chlorides, so the molten steel contained in the molten slag aggregates and settles. The eaves P portion rises in the molten slag and is volatilized. Through the above process, steelmaking slag and P removal
Iron and P are separated from the slag.

The slag from which the iron and phosphorus components have been separated is subjected to a slag in a water l'f facility in the 3rd L stage. As methods for transferring the molten slag from this processing furnace to the slag equipment, there are a method in which the molten slag is transferred from the processing furnace to the -r3'rl'J molten slag in its entirety, and a method in which the molten slag is transferred through a gutter.

In the fourth step, after a certain amount of metal has settled in the lower part of the processing furnace, it is taken out and used as a metal source as described above.

[Embodiment 1] Next, a first embodiment of the present invention will be explained with reference to the attached drawings.

As shown in FIG.
A tuyere burner 11, which is an example of an auxiliary heat source generator, is installed at O.
is attached. This tuyere burner 11 has a processing furnace body 12.
It is attached to the bottom side of the furnace, but in large furnaces,
The molten slag is arranged at an angle with the radial direction so that the molten slag inside can rotate from a diagonal direction or from three directions.

Note that instead of this tuyere burner 11, as shown in the figure,
It is also possible to install a lance-shaped burner 13, which is an example of an auxiliary heat source generating device, through the furnace l114. In this case, in a large furnace, the tip 15 is divided into two parts as shown in the figure.

There is a molten slag outlet I6 on the side of the processing furnace body 12.
A spout 17 for molten metal is provided.

Further, the furnace lid 14 is movable and lined with refractory material, and inside thereof is provided a breathable radiator 18 that reflects heat and improves thermal efficiency. Heat exchange tower 1 performs heat exchange by spouting water in the form of a stream.
After passing through 9, the dust passes through a wet dust collector 20 and is discharged into the air.

In step 10, the steelmaking slag in the molten state, which also contains the assimilated slag (including pot skin and surface hardened slag), which is partially taken out from the IJE from the converter or takeaway 1f:M, and the dephosphorized slag. 3~+0+R11t% of the melting point viscosity reducing material and 3~5% by weight of chloride were charged, and from the above tuyere burner II,
Oxygen and kerosene or oxygen and COG gas, etc. are injected to raise the combustion temperature and completely melt the steelmaking slag (first step,
2nd step). By this, the light P portion is upper 51' L
As the metal becomes II, heavy metal components settle to the bottom.

After that, the molten slag is taken out from the slag outlet 16, received by the ladle 21, and poured into the slag gutter 23, which is the population of the molten slag in the slag installation 61m22. At the bottom of 23 is a high pressure water generator i'? Nozzle 2 connected to 25
4 is provided, and the flowing molten slag is blown off with a water jet chef), allowed to settle in a water tank 26, and solid-liquid separated using an Akins 27 or the like. This solid-liquid separated water slag is transported by a container 28 and stored in a hopper 29.

After this, it is transported to a magnetic separator 32 by a conhair 31 and sorted.
'+(, iron to -1,・'"? 33C1 Zunova 34
To J8I! Ha'tl, 58! It is returned to the steel furnace and used as a source of iron.

On the other hand, the slag is classified by the vibrating sieve 30 and stored in the hopper 35.35a according to size. ! It is used for auxiliary raw materials, dawn raw materials, i￥3 board materials, sand, etc. 6 Furthermore, since this water slag treated material has a latent water effect, stimulants such as lime or gypsum should not be added. , Hetrohardening (E) Used as a cement admixture, briquette, and binder during pellet production (3rd step above) The metal content accumulated at the bottom of the processing furnace 10 is 1500 to +550"c in the case of back A steel. Since it does not dissolve, after a certain amount of liquid has accumulated over several cycles,
The temperature is raised to 1600° C. to melt the melt, and the melt is discharged from the tap into the ladle 36. and? The 4th step is to either charge the steel in the II furnace or make it into an ingot and return it to the steelmaking furnace.

Incidentally, the P volatilized from the steelmaking slag and the dephosphorized slag by the heat exchanger I9 and the dust collector 20 described above is absorbed into water and partially converted into boric acid and recovered at °C.

In addition, in the embodiment described in -1-, the treatment time is 10 to tJ
The molten slag discharged from the bath was put into the ladle 21 into the water bath 22, but it is also possible to put it directly into the water source equipment 22 via a gutter.

[Example 2] Next, a method for treating steelmaking slag and dephosphorous slag according to a second example of the present invention will be described with reference to FIG. Since it is the same as
The explanation will be omitted, and only the previous steps, which are the goal of (■), will be explained.

Components that are the same as those shown in FIG. 1 are given the same numbers and their explanations will be omitted.

As shown in the figure, a processing furnace 10a capable of handling 111' is lined with maggot-free carbon bricks that do not easily react with slag. In addition, the furnace 1i14a is mobile and is made of refractory (Ah
The ventilating radiator 18a described above is disposed inside the ventilating radiator 18a, and the tJ gas that has passed through the ventilating radiator 18a passes through the heat exchange tower 19 and the dust collector 1i20 into the atmosphere. is being released.

In this processing furnace 10a, the steelmaking slag discharged from the converter or ladle, the removed 1) slag (boiled surface, surface hardened slag), and I to j'1
．． II! , l(() and 1Δm conversion '1 force is inserted ζ furnace cover 14a is removed, supply 'a14a (1 digit C color t +
li 19) Burner 11, 1, which is an example of a firing device
From there, oxygen gas and LPG gas or oxygen gas and kerosene are blown onto the molten slag to raise its temperature and completely raise the temperature to 7 hours. This separates the P content and metal content in the steelmaking slag and deP slag (1st step, 2nd - [culm)] After this, the processing furnace 10a is tilted to flow out into the wind crushing gutter. (Hereinafter, the third step).

The metal that sank to the bottom becomes 16 (
After melting at 10°C, the processing furnace 10a was tilted, and the mixture was placed in a ladle and returned to the #4 furnace made by 1ilil.
Use it (Step 41).

[Example 3] Next, a third example of the present invention will be described with reference to FIG. 3, but since the method shown in FIG. 2 is different from the auxiliary heat source generator attached to the processing furnace, It is f.

Immediately, the furnace Ml 4.1, which has a processing capacity of 10a, has the same power as normal electric ψ. (Three electrodes 37 are installed in the city of C.

The steelmaking slag, dephosphorization, and zeta lag to which the above-mentioned additives have been added are used in JJII.

〔experiment〕

Experiments conducted to confirm the effects of the method of the present invention and their results are shown below.

Experiment n materials shown in Table 1 and Table i2 were used.

After drying the raw 'f' material in a constant temperature dryer at 105~1ltl °r for more than 24 hours, it is ready for production. Materials such as J slag were roughly crushed to 3 mm or less using a sample grinder, and only the steelmaking slag and dephosphorization slag were magnetically separated, and the non-magnetic materials were placed in an electric melt magnet/alumbo, and then heated in a Noriko Ni-no-do city air furnace maintained at 1530°C. Hold for 10 minutes, add F# molten salt chloride at 1530℃, insert a lance for 3 minutes and blow air to create bubbles, hold for 7 minutes, let it cool out of the furnace, and cool it in air. It was cut into two parts, a middle part, and a bottom part using a Rehintkanotar, and chemical analysis of CaO, 5iOz, MgO, P, etc. was conducted.

See Table 3 and Table 4 S for the blending ratio (weight %) of each material.
b no.

(People's condolence r14k Iko, each [[$1 arrangement: N1! Rino iW ffs410 (JISt University:, Ro Seril:
Press ζ) on +-n.

Table 5 In addition, Table 6 shows several examples of viscosity measurement results using a Luch rotational viscometer (capable of measuring up to +00 voids).

As shown in I above, the '11121'' Sunoku shell ζ has a very high melting temperature and Ri degree, but when silicate rocks, minerals, etc., which are examples of melting point viscosity lowering materials, are added,
It can be seen that both the temperature and viscosity of the W example decreased dramatically.

Next, when steelmaking slag alone is remelted, when silicate rocks, minerals, etc. are added to steelmaking slag and it is remelted, steelmaking slag is mixed with silicate rocks, minerals, etc. Add it, blow air with a lance pipe for 3 minutes,
Tables 7 to 13 show some examples of cases in which the samples were cooled after being held for 5 minutes.6 Tables 7, 8, and 9 Tables 7 to 9 show specific gravity separation by remelting. Examination box:+:
6' people, - Ill understand clearly, L'I's IL
! 1' 51, if j+c As shown in the several examples of fruit withering, rolling slag alone is not good, but when the melting point and viscosity are lowered, the phenomenon becomes remarkable.

Table 10 II, C 12 AL Table 13 Based on the above, when steelmaking slag in a molten state to which silicate rocks, minerals, etc., which are an example of melting point viscosity lowering materials, are added is left to cool, the upper layer In the upper layer, P, CaO, MgO, etc. are high, and in the lower layer, TFe, Mn are high, and P, CaO
becomes lower.

However, if more chloride is added to the molten slag, =\
I' ll :"'I",, H), : j: H, Shi, Renochihihe, l) has also become 1φ, ζ, the ■ of P remains the same in the central, central, and to parts, and the overall P It can be seen that the amount decreases.

Furthermore, the more chloride added, the more effective the amount of P remaining.

18, slag treated with 1 + water according to the method described in F (contains α' and β-2Ca0.5i (h) in one glass body)
After drying, it was crushed to about 200 mm or more, lime was added to 61%, water was added and kneaded, and the mixture was placed in a plastic bag and the hardening status was examined. The results are shown in Table 14.

Table 14 69! X is hardening/(
(Also in Chapter 11 &).

Calcium chloride, Panom 3% was added to the mixture of Gogo C2 mixture Nt + 4.21, and water IF treatment was carried out. The product treated with water slag was cured within about 10/)1.

Next, the prototype water slag was applied to hetero (kaolinite, montmorillonite, α-quartz beads) with an adhering moisture content of 31) 5%.
1 crushing (4% + 200 menonyu or less - Blaine value YJ50
0c "/g) L, 3 to 5 times stimulants such as gypsum and lime
%, mixed in a mortar kneading pot, and packed in three layers with a rammer in a f-quality test mold (Sd;) After 1 month in humid air 6: Some examples of the results of examining compressive strength are shown in Table 15.

Table 15 Next, Fcao, surface fracture/slant,
Table 16 shows some examples of water absorption, surface dry specific gravity, and dissolution test results.

In addition, in Table 16, the elution ion concentration is
? '1 small force method, loid exam b (jl i+!
i l*'t: ! , 1△S 'r M method (2(1(
1° (held at 20J/cm for 2.3 hours) 2.
The test was carried out at a consistency of 5 to 1.2 ml, and pieces of 1.2 mm or less were considered to be disintegrated. In addition, the water absorption rate and surface dry specific gravity are JISA Allt.
It was held 11 times in January.

(Effects of the Invention) As described in d), according to the present IQ1 method, steelmaking and dephosphorous slag, which is an unused resource and is difficult to dispose of, is available nationwide, and silicate rock, which is an unused resource, can be used. Or industrial waste such as red IQ, glass scrap, etc. and chloride are used to modify the slag and volatilize it. , cement admixture,
It increases the utility value as a resource such as binder or sand during the production of briquettes and pellets, and furthermore, the iron contained in the molten slag can be used as an iron source.

In addition, the method of the present invention makes it possible to reform and dephosphorize even molten slag containing partially solidified slag.

In history, since the slag from the molten sandwich is used as a water slag, there is no need for machine equipment such as Kuranonoya.

4 U! JJ's section! I-I'J! Fig. 1 is a process explanatory diagram of the first embodiment of the present invention, and Fig. 2 is a process explanatory diagram of the second embodiment of the present invention.
, L t, Nohi Akira...) Condolences (b' Explanation of the 1st degree explanatory diagram of the 1-person example in Elementary J, No. 21)] 10.108 Treatment, 11 birds [1 burner (auxiliary theory origin! 1- Device 1, 11a burner,
(Drawing control device), 13 lance-shaped burner (
Auxiliary information source determination device), 16 out? M iT ], 1
7 Tap water outlet, I9 Rib exchanger, 20
4 2 dust collectors, 22・k1 installation (lii, 24 nosuru, 25 high pressure water generator, 27 Akins, 28.31.33 co/hair, 30 vibrating sieve, 32 Yujin machine, 29.3i, 35.35.
I Hopper, 36 Ladle 1.37
・K pole patent applicant: Nippon Fil Chikara Sensing Co., Ltd. Agent: Chubu Fujio Fig. 2, 10, Fig. 6

Claims (5)

[Claims] (1) 3 to 10% by weight of a melting point viscosity reducing agent is added to molten converter slag, agglomerated slag or dephosphorization slag discharged from a converter or ladle and containing molten or partially solidified slag. and 3 to 5% by weight of chloride, and the converter slag, agglomerated slag or dephosphorization slag to which the above additives have been added are heated and melted with an auxiliary heat source generator in a processing furnace. A second step in which the phosphorus contained in the slag is volatilized and the metals in the slag are settled to the lower part, and the slag from which the metals have been separated is taken out from the treatment furnace and is turned into a water slag in a water slag equipment to be used as a resource. A method for processing steelmaking and dephosphorization slag, characterized by comprising a third step in which the metal that has settled in the lower part of the processing furnace is used as a metal source, and a fourth step in which the metal that has settled in the lower part of the processing furnace is taken out and used as a metal source. . (2) The method for treating steelmaking and dephosphorizing slag according to claim 1, wherein the auxiliary heat source generator of the processing furnace comprises a lance-shaped burner that blows out oxygen gas and liquid fuel or gaseous fuel. (3) The method for treating steelmaking and dephosphorization slag according to claim 1, wherein the auxiliary heat source generator of the processing furnace comprises a tuyere burner that blows out oxygen gas and liquid fuel or gaseous fuel. (4) The processing furnace auxiliary heat source generator is attached to the furnace lid,
A method for treating steelmaking and dephosphorizing slag according to claim 1, comprising a burner blowing out oxygen gas and liquid fuel or gaseous fuel. (5) Steel manufacturing according to claim 1, wherein the auxiliary heat source generator of the processing furnace is an electric furnace that generates heat using electric power;
How to treat derinsing slag.