JPS5950130A - Pretreatment of starting material for sintering - Google Patents

Abstract

PURPOSE:To increase the reactivity and to improve the productivity of sintering and the quality of sintered ore by blending an inferior starting material with a specified amount of pulverized lime of a proper grain size of prepare a starting material for sinering. CONSTITUTION:Fine iron ore as an inferior starting material which exerts an unfavorable influence on the quality of sintered ore is blended with pulverized lime of <=0.25mm. grain size, and the inferior starting material is formed into pseudo-granules. The pseudo-granules are fed as a starting material for sintering. The amount of the pulverized lime to be blended is 5-15%. The reactivity of the starting material during sintering is increased, the productivity and the rotating strength are improved, and the coke unit is reduced.

Description

[Detailed Description of the Invention] The present invention (d) relates to a method for pretreatment of sintered raw materials, which improves the reaction conditions of fine ore that adversely affect the quality of sintered ore, and reduces the adverse effects as much as possible. .

Sintering raw materials are various powdered ores, iron-containing raw materials, etc., usually 10 to 13
About 5 to 20% of each of these types are blended, and 13% of the amount of sintering raw material is added to the predetermined amount of 5i02 so that the basicity CaO/5i02 required for blast furnace operation becomes a predetermined value.
~14% powdered lime and further auxiliary raw materials such as coke are added, mixed and granulated using a mixer, and then sintered. However, among the various raw material brands to be mixed, there are ores that are less favorable in terms of productivity and quality of sintered ore than other fine ores, such as Hamersley Bore ore and #iron. In general, coarsening of crystals is known to be a cause of strength deterioration when iron ore is reduced.
It is said that L203 promotes the coarsening of calcium ferrite in the bond area and the vitrification of silicate, thereby weakening the tissue surrounding hemaquite. According to the results of analyzing the operation results of ore, the component in ore is S7?203.5
It is closely related to the ratio of i02, A4o3 (%) x Az
Calculated value by 2oa (%) / SiOz (%)1
．． Ores with a rating of 5 or higher, such as the aforementioned Hamasley fist gore and iron sand, are unfavorable in terms of productivity and quality. However, these ores are unavoidably mixed for various reasons.
However, no special measures have been taken in the past to deal with this, such as simply subjecting it to pseudo-granulation treatment like other ores, or setting the blending ratio to minimize the negative effects caused by it. However, the measures taken are still in place.

The inventor of the present invention has conducted experiments and research on the processing of powdered ore, which has a negative effect on sintering productivity and sintered ore quality, and has found that powdered lime is evenly mixed throughout the sintering raw material. outside,
In order to increase the chance of contact with the fine V powder lime for the above-mentioned fine ore, by blending fine lime of 0.25 m+ or less with other raw materials separately, its reactivity is significantly improved and sintering productivity is improved. It was found that the quality of sintered ore could be significantly improved.

The present invention was made based on this knowledge, and it is necessary to apply a grain size of 0.25 wm to fine ore that adversely affects the quality of sintered ore.
It is characterized in that the following fine powder lime is blended at a ratio of 5 to 15% and then used as a sintering raw material.

In the method of the present invention, the particle size of the pulverized lime to be added in advance to the inferior raw material, which has a negative effect on the quality of the sintered ore, is set to 0.25 W or less. This is because the reactivity and adhesion to ore particles rapidly decrease due to expansion. In addition, when the amount of finely mixed lime is set to 5 to 15%, if it is less than 5% or more than 15%, it has little effect on improving the quality of sintered ore and non-production. Since basicity Cab/5in2 is determined, it is necessary to reduce the amount of powdered lime to be charged.
This is because the overall productivity and quality of the sintered ore decreases. Furthermore, since the sintering raw material contains Si in an average range of 2 to 5%, when a certain amount of CaO is added, variations occur in the Cab/5in2 value, but this has almost no effect. It is negligible.

Next, examples of the present invention will be described. The target inferior quality raw material is SFH, its particle size distribution and main components are as shown in Tables 1 and 2, and A1203 (type) XA.
j? The value of 203(%)/5in2(%) is 1.64.

Table 1 Table 2 Such inferior raw materials 20 K9 were mixed with 3,5,10,15,20% each of finely powdered lime with a particle size of 0.25wM or less and thoroughly mixed in a mixer, and the weight ratio of each inferior raw material was 1
5% and each high-quality raw material prepared separately was combined at a weight ratio of 85%, and then 1 part of powdered lime was added to 100 parts of this mixed raw material.
Add a certain amount of coke,
After adding water and the like, the mixture was granulated using a mixer and then sintered.

Reference examples include a conventional method in which no fine powder lime is added to the inferior raw material, and a sintered raw material in which the mixing ratio of the raw materials is the same even when the amount of fine powder (i) mixed with the inferior raw material exceeds the set range in the present invention. The production rate (T/D・〃〆), rotational strength (%), and coke consumption rate (K9/T-5) are determined for each sintered ore obtained. , Cab (%) in the product, CaO
The dispersion (σ) was investigated. The result is the drawing (a) ~
). As is clear from the drawings, when the method of the present invention is applied, the production rate, rotational strength, and coke consumption rate are significantly superior to other methods. In addition, there is almost no difference in Ca0jd and its variation in the product whether it is pre-mixed in No. 17 or 20%, and it can be said that there is no particular problem in pre-blending fine powder lime into a single brand.

In addition, although the above-mentioned example was explained in the case of a single brand of inferior raw material, when using a mixture of multiple brands of inferior raw materials, fine powder lime can be added to each brand in a predetermined preferred ratio. Of course, the method of the present invention can be modified by setting and mixing.

As described above, in the method of the present invention, the inferior raw material that has a negative effect on the fluffy L 2-concrete product q'1 is made into pseudo-particles after being properly mixed with finely powdered lime and adhered thereto, and then sintered. However, the reactivity of inferior raw materials is increased by the fine powder lime brought into contact with the raw materials, and the quality of sintered ore and productivity of sintering are significantly softened, and the present invention has excellent effects. It is something.

[Brief explanation of the drawing]

Drawings (a), (b), 0, and 2) are graphs showing the results of comparative tests between the method of the present invention and the conventional method. Procedures Sleeves Authorized (Method) Born January 28, 1982 2 Title of the invention Pretreatment method for sintering raw materials 3 Relationship with the case of the person making the amendment Patent applicant D1 Attorney J, Date of amendment order Showa On January 5, 1958 (shipment date 58.1.25), the "Detailed Description of the Invention" of the specification to be amended and the details of "The third vehicle in the drawings, the eyebrows and rivers" as well as the drawing 7. 7-1 "Detailed explanation of Departure 1" from page 5, line 16 to line 17 of the same page ("The results are shown in drawings (a) to 1)" of the phase d specification Correct the sentence ``tomaru・ri deru5,'' as follows. [The results are shown in the graphs in Figure 1 (a) to (a). In Figures 1 (A) to (A), the horizontal axis shows the lime mixture ratio, and the thin axis shows the production rate in Figure 1 (A), and the production rate in Figure 1 (A). If there is a finished product Cab (%) shop CaO
The i-f fluctuation (σ) of is shown in a large scale. ”
(7-21J-1 wholesaler's note 1 of "Drawing tA1 simple explanation 1" is corrected as follows. [Figure 1 (A), Naka), H, Ni)] It is a graph showing the comparison 'dl MiC test results between the Kikori 4 method and the conventional method. Figure 7-3]... As shown in the attached sheet, it is a list of salaries (1)! J stop drawing 1 Not traceable 1
closed

Claims (1)

[Claims] 1. Particle size of 0.25 is applied to fine ore which adversely affects the quality of sintered ore.
1. A method for pre-treating a sintering raw material, which comprises blending finely divided lime at a ratio of 5 to 15% and then providing the mixture as a sintering raw material.