JPS58185728A - Manufacture of sintered ore for raw material of blast furnace - Google Patents

Abstract

PURPOSE:To manufacture simply a sintered ore suitable for a raw material of blast furnace from a material containing Zn, by granulating a powdery material containing high Fe and high Zn produced secondarily in ironworks to pellets of suitable C content and by sintering the pellets in the atmosphere capable of reducing ZnO to Zn. CONSTITUTION:A powdery material containing a large amount of Fe and Zn produced secondarily in ironworks is used as the main raw material and C content of said material is adjusted to 7-18wt%, and the pellets of 2-8mm. diameter are granuated. These pellets are laid in 20-50mm. thickness as a firing layer on a formed bed layer of the sintered return ore on a fire grating and suction ventilation is performed from the bottom of the fire grating by firing said layer. Said pellets are furthermore laid thereon in 200-400mm. thickness and the ventilation direction is changed upward. The ventilation amount is controlled to a range of 0.1-0.3m<3>/kg (pellets). ZnO is reduced, the sintering is performed while dezincifying as Zn vapor and the sintered ore for raw material of blast furnace is obtained.

Description

[Detailed Description of the Invention] 4. The invention is the effective use of high Zn-containing substances that reduce the dust system M, force, and %1 in the ironmaking and steelmaking process. In more detail, this method involves the formation of an atmosphere during sintering in which the oxidized zinc in the Z11 material is reduced by lead vapor, VC, C, Zn, and π for the blast furnace at the same time. This invention relates to a method for producing suitable sintered ore.

It is a by-product such as dust generated in steel mills, and has a high iron content, so it is desirable to use it as a raw material for steel production, but due to various constraints, it is often not possible to fully utilize it. .

For example, when a thickener cake of blast furnace dust or converter dust is used as part or all of the gold sintering raw material, the Zn present in the cake cannot be removed by normal sintering methods, resulting in sintered ore with a high Zn content. If this is charged into the entire blast furnace, it will cause so-called Anzac (adhesive galls) to be formed in certain areas of the blast furnace, causing problems in blast furnace operation, so its use is restricted from Zn balance considerations.

Therefore, it is advantageous to classify or separate the dust into Zn-rich parts and Zn-poor parts as much as possible to diversify its use. For example, blast furnace dust treatment system M, odor, /nukunake, -ki total π wet classification [2, high Zn content (usually also high carbon content)] In addition, in the converter dust treatment system, since the Z11 content in the dust changes depending on the time of steelmaking operation, steelmaking dust is continuously
'J1 method of separating collection into multiple parts over time (for example, Japanese Patent Application No. 56-491524 filed by the same applicant VC)
Since dust 1 containing less Zn and dust containing more Zn can be separated by 10 times, there is an extremely large amount of VC in L, which aims to utilize dust in multiple ways. In this case, Z
Even if dust with low r1 content -1 can be used as a raw material for steelmaking,
The problem is that dust containing a large amount of Zn (41) is a problem.

The purpose of the present invention is to make effective use of the dust containing a large amount of Zr and waste, especially when it is obtained through the treatment described in 7.E. The purpose of the present invention is to provide a complete treatment method that can process even high Zr+ dust into the alpha phase (for steelmaking).

General 9. Such materials with high Zn content must be disposed of, otherwise they may cause environmental pollution, so they can be used separately as a source of recovered Zr+ bones, but there are various problems in their handling and processing methods. For example, it is difficult to operate and manage Vc even if it is reduced and roasted in a tarry kiln. A sufficient Zn removal effect cannot be expected, and the exhaust gas system requires a large amount of power and equipment in order to perform chloride roasting using suspended calcium chloride.
As proposed in Publication No. 02, if a method such as charging into an existing sintering machine and completely reversing the suction direction after ignition is applied, ZnO and other materials such as pbo, Na, ..., O, K2O, etc. It is unavoidable that it will adhere to the grade and piping parts of the sintering machine during operation and cause problems in the sintering operation.

The inventors of the present invention have carried out various experimental studies in order to find a simple and effective treatment method for this type of high Zn-containing material, with the above-mentioned objectives and aspirations in mind. As a result, such high Z
After adjusting the n-containing material so that its carbon content is 7 to 18% by weight, it is granulated into pellets with a diameter of 2 to 8 mm using this as the main raw material. For the discharge of sintered ore, a scattered ore deposit layer is completely formed on a grate that can be rotated and moved, and the layer is laid to a depth of 20 m or more, but not less than 50 m, to form an ignition layer, and the ignition layer is ignited. Downward force of the grate・5-Ra no 1 and Hikiura'-Aga line NatsulAfter this, [)11 ignition layer hπ1Uyko the above-mentioned beret i 200-400m Door thickness installation-111! Change the 1-ki direction to the 1- direction,
This aeration 11i is controlled within the range of 0.1 to 0.3 intensities ω1], and when the reduction reaction is fully progressed, the Zn content (z[10) in this raw material is It has been found that sintered crystals can be obtained which can be reduced and removed efficiently and which can be used as sintered ore for blast furnaces.

In the case of the method of the present invention vc, Zllo + Co −+ Co,, −+
znIAA)
-(llL''e',,l + Co ” CO21
F+>・”7r+ according to f21VC
Among the reduction reactions of O or FeO, Zr+0 in formula (1)
7) The reduction reaction proceeds with priority over the reduction reaction of deO in formula (2). Both reactions are thermodynamically approximately 1100C
Below, the reaction of formula 42) takes priority, and the reaction of formula (1) proceeds preferentially at temperatures above about 1.100 C. However, according to the method of the present invention, the reaction of formula (1) takes priority. can do 1
A feature of the present invention is that the conditions for this are determined in the sintering process.According to the test results of the present inventors, as shown in the examples below, -6- in the Zn-containing material is The carbon content is 7-18% by weight, and the pellet diameter is 2-2.
8 Jim, it is necessary to ignite with a layer thickness of 200 to 400 mm, and if even one of these conditions is violated, Zn removal according to equation (1) cannot be performed sufficiently. In carrying out the project, the raw materials used are as mentioned above ((, high Zn-containing dust whose disposal has been a problem,
More specifically, the high Zn-containing dust separated in the blast furnace dust treatment system and the converter dust treatment system VC
High Zn-containing dust that has been separated can be used above. The former is used as an overflow from wet classification of blast furnace dust, and the latter is used as an overflow part obtained by wet classification of blast furnace dust, and as described in Japanese Patent Application No. 56-191524 by the same applicant. It can be collected as the dust of the high Zn-containing part obtained by fractional collection in the former overflow part vc. The carbon content is also concentrated together with the zinc part, and the carbon content is very high m!f!- (usually 60 ~
50 double blows). Therefore, it is advisable to mix this dried material with the latter dried material of steelmaking turst in such a proportion that the total weight will be 7-18 tons per cycle.

Then, the sintered ore waste produced as a by-product as a result of carrying out the method of the present invention, or the sintered ore dressing I of (1 ordinary iron ore)
Mixed lace may also be used as an auxiliary raw material, such as sintered dust produced during the inking process. Even if such auxiliary raw materials are blended/C, it is necessary to rub the raw materials by 1F so that the carbon content in the total raw materials is 7 to 1811 cm. Carbon r has l in 18
Contains a large amount of carbon that exceeds % gold, and when S is used, it has a strong and even de-zn effect). This is thought to be because the τ pellets melt and soften during the reaction, resulting in an extremely reduced area of the reaction interface. - 10,000, if the carbon residue is less than 8%, the sediment removal will be 1:1 - 3, this is 1 or C0J 3 degree in reaction 1C of equation (1) is 2 -t70
)'i)・Radaro 4, in this process, the powdery Zr+ material which has been completely adjusted to contain IC is granulated vC and then tJ1
It is necessary to set the berenoto tweezing to 2 to 8 mm. Bm
When granulating with a diameter F larger than m, the desorption:≦11 effect is significantly lowered.

-8- It is thought that this is because the partial pressure is low (-.1, 2m
When I/C granulation with a diameter of mL s'j-σl progresses, melting and softening of the pellet progresses and the Zn removal rate also deteriorates, resulting in a decrease in both the yield quality of the Ic1 sintered ore.

- The sintering process (with the aid of a pivotable grate for fixation and discharge of the sintered ore) can be carried out by upward ventilation. If a dust collector is fully installed to collect dust in the generated gas and the dust is collected in the middle of the dust removal path, high Zn can be used as a raw material for zinc smelting.
Containing secondary dust can be used.

In this sintering process, a bedding layer of return ore is first formed on a movable grate for fixing and discharging the sintered ore, and then the sintered ore is sized to the above-mentioned particle size. Pellets (dry pellets) are ignited completely 1 - Tie and laid on 20 to 50 mm Ignition - T 3, this thickness is less than 20 mm until V,
Afterwards, the ignition of the pereno (200 to 400 meters) that will be laid may be insufficient, and if the distance is 50 meters or more,
However, it has no effect on ignition, but rather extends the rotten ignition time, so it is limited to this range.
Then, lay a layer with a thickness of 200 to 400 ml (~1 upward lF in the ventilation direction - change 1, if this layer thickness exceeds 400 mm, it will become a sintered layer, and the Zn removal rate will increase [
Even if the temperature is low, a sintering reaction of 1 minute cannot be obtained, so it is better to set the temperature to 200 am or more. The effect of &J removal of Zr+ becomes ・J＼ when the ulm"/ is less than 9 (berrett), and even if this wear exceeds 0.3m'/89 (helet), this effect is saturated -r, so ventilation is The amount should be 0.1-o3mJ/!? (It is better to use Pereno l-3.

Hereinafter, the μ orientation 1C will be explained based on examples in FK and V).

Example Table 1 shows the chemical composition (Φ%) of powdery Zn-containing dust obtained from the blast furnace dust treatment system and the converter dust treatment system. II is the analytical value of the Nokner cake, and II is the analytical value of Oh half 0-min obtained by wet classification of the Nokner cake, and Z
n and () increase, T, FQ ()-TalFe)
10-- This is the analysis value of the soil cake of the Illir converter dust, and it is during the period of time when the amount of evaporation of Zn is particularly high during one cycle of IV rJ converter operation. The amount of Znn deposited was increased by separating and collecting Znn from other time periods and introducing it to Nnokuna.

After drying the above-mentioned high Zn-containing materials (■) and lVi, they were mixed under the blending ratio of Meat Meal Ink Table 2 FJ, the carbon content was as indicated, and the pellets were granulated to the indicated pellet size.
A bedding layer of return ore is fixed and laid to the indicated thickness on a grate that can be rotated for discharge of sintered ore, ignited with forced downward suction ventilation, and then The display pellet was placed on the top surface, and the ventilation direction was changed to all upwards. The exhaust gas was led to the cooler through the exhaust foot 5. As a result, sintered ore having the composition shown in Table 2 was obtained, and lead was collected in the cooler. In Table 2, IQJ is a comparative example, and shows one in which one of the six conditions specified in the present invention regarding carbon content, pellet particle size, and pellet laying thickness was not met. That is, Fgepere 11- Notobuis is less than 2 mm, o has a pellet size of more than 8 mm, H has a C content of less than 7 mm, and ■ has a laying thickness of 200 mm.
If the thickness of the laying layer exceeds 400 m1ffi, and the other two conditions are satisfied, but one condition is not met, the Zn removal rate i! It can be seen that the sintering yield has decreased significantly and the sintering yield has also decreased. In addition to this, in the case of the present invention methods (A to E) that satisfy 6 conditions, good Zn removal is achieved.
The sintering yield is also high. Therefore, according to the method of the present invention, Zn-free sintered ore, which can be fully utilized as a Fe source and a raw material for blast furnaces, can be obtained from Zn-containing materials, which are by-products of ironworks and have a high Zn content, in a simple operation. , and together with Z
n collection can be easily performed, and resources can be used effectively with simple equipment.

Claims (1)

[Claims] (1) Substitute AZ containing all Fe and Zn produced as by-products in steel works
n material as the main raw material, C-containing material in this main raw material
~18% by weight range 11'c after adjustment 2~8mm
Fl pellets Ic were granulated, and the pellets were added to a furnace with a thickness of 20 mm or more in H5, where a bed layer of sintered return ore was completely formed.
Lay 0mm 1avc and use it as an ignition layer, this ignition layer!
After that, ignite the fire and suction ventilation from below the grate, then add 200 to 400
After laying the pellets to a thickness of 1 mm, the ventilation direction was changed to upward @ π, and the ventilation amount was controlled within the range of 2 ++ 1 to 3 m'/kg (pellets) to allow the excursion reaction of Zn oxide to proceed completely. A method for producing sintered ore for use as a raw material for a blast furnace, the main component being a Zrl-containing substance, which comprises sintering. (2) Powdered Zn-containing substance/r↓, blast furnace dust treatment system M
/C/High Zn obtained by wet classification of Nokner cake
The Zn containing fraction is separated and collected according to the time and total during converter operation in the converter dust treatment system (T);
Claim IJU which is a mixture with the τ shoulder portion;
Production of sintered ore described in Section θ. (S() Powder: ”+-1rl '491J 'iQ
Contains more than 45 weight M% of 1-tal iron!
+! f♂To1 Required RangeCrow1 DimensionsIn addition, the method for manufacturing sintered ore described in Item 2, (1) Pereno i/medium σ) Carbon content grade is high carbon content Zn-containing Adjustment of the composition of the sintered ore according to claim 1, 2 or 6. (5) The grate is a portable grate that can be moved around for discharging sintered ore. '-F Claims 1 and 2
Item,・86 item-! or the method for producing sintered ore described in Section 4.