JPS5950129A - Pretreatment of starting material for sintering - Google Patents

Abstract

PURPOSE:To obtain easily pseudo-granules of a starting material for sintering provided with suitable characteristics by using water contg. small amounts of a dispersant and a surfactant when the starting material is mixed and regulated to a prescribed water content. CONSTITUTION:A starting material for sintering prepared by combining fine iron ore with quick lime is blended with water contg. 0.01-1.0wt% dispersant and 0.001-0.1wt% surfactant, and they are mixed, regulated to a prescribed water content, and formed into pseudo-granules. Sodium acrylate, methacrylic acid hydroxyethylate, a methyl acrylate copolymer or the like is used as the dispersant, and a condensation product of naphthalenesulfonic acid with formaldehyde or the like is used as the surfactant. The pseudo-granules have a stable shape and superior mechanical strength, and they can ensure gas permeability when charged into a sintering machine. Accordingly, the productivity and yield of sintered ore can be improved.

Description

[Detailed description of the invention] The present invention relates to a method for pretreating sintering raw materials.

Sintered ore is made by partially melting fine ore to form agglomerated ore, and is used in large quantities as a raw material for iron manufacturing.

This is generally done by blending coke powder as a fuel with raw materials such as ore powder, return ore powder, and limestone, then adding water and granulating it at a controlled temperature.The resulting sintered raw material pseudo-granules are then charged into a sintering machine. It is obtained by firing. However, in the commonly used sintering machine (Dwight Lloyd type), the surface layer of the raw material grains is ignited in an ignition furnace, and air is sucked downward to burn it to the lower layer. Air permeability greatly affects the productivity of sintered ore products. Therefore, the granulation properties of the sintered raw material have been improved compared to before, and
Various methods have been studied to improve the pseudo-granulation and ensure the permeability of the raw material grain layer. As a typical example, a method is known in which fine powder ore and other ores are adhered and granulated using a so-called visiter component such as quicklime or slaked lime. However, in this method, it is necessary to add a relatively large amount of quicklime, etc., which increases the raw material cost and offsets the productivity improvement effect. In addition, quicklime generally becomes slaked lime when it comes into contact with water, and at this time it becomes hydrated and becomes coarse grained by using water as bicedar, but the coarsened slaked lime no longer has the original bicarbonate.
/ performance is lost, and it becomes difficult to produce the granulation property of sintering raw materials such as fine powder ore, that is, the pseudo-particle effect.

In view of the above-mentioned current situation, the present inventors have realized that pseudo-granulation of sintered raw materials can be easily and reliably carried out using only a very small amount of binder such as quicklime, and that each granulated particle itself has structural stability and mechanical strength. Not only is it easy to handle, but it also ensures the permeability of the sintered raw material layer after charging into the sintering machine, improving the productivity of the sintered ore.
We have conducted intensive research with the aim of establishing a pretreatment technology for sintering raw materials that can improve yields and other factors. As a result, when a predetermined amount of dispersant and/or surfactant is added to the water used for mixing, humidity conditioning and pseudo-granulation of sintering raw materials, the above objectives are achieved and excellent properties are achieved. It has been discovered that a pseudo-granulated product (granulated product) can be obtained and is extremely suitable as a raw material for sintered ore.

The present invention was completed based on the discovery of this new fact.

That is, in the present invention, a dispersant with a concentration of 0.01-1.0% by weight and (
or) A method for pretreating a sintering raw material, characterized in that water containing a surfactant at a concentration of 0.001 to 0.1% by weight is used.

According to the method of the present invention, it is possible to easily obtain a sintered raw material pseudo particle weight having various characteristics extremely suitable as a sintered ore raw material, and only by using a very small amount of a binder such as quicklime. The pseudonucleus obtained by the method of the present invention has a stable shape, excellent mechanical strength, and can ensure air permeability when charged into a sintering machine, improving productivity and yield of sintered ore. It can be significantly improved. In addition, even if the particles are subjected to vibration during transportation to the sintering process, they will not bond to each other or grow into large lumps, and even if they are partially bonded, they will be easily separated into individual pseudo-nuclei crystals by crushing. This method does not cause any problems in the sintering process. Furthermore, the sintered ore produced using the pseudonucleated crystals has improved strength.

The reason why a sintered raw material pseudo particle weight having such excellent properties is obtained by using the above-mentioned predetermined amounts of dispersant and/or surfactant according to the present invention has not yet been elucidated. However, the wettability, permeability, water wettability, etc. of surfactants improve the wettability of iron ore, which is a raw material for sintering, and facilitate the formation of pseudo-particles. (crystal growth prevention effect) and dispersion effect (repulsion effect between particles due to surface potential adjustment), it is possible to make the lime particles finer by using a small amount of vigitr effectively. It is thought that this can improve the pseudo-particulate property of the coagulating material. Further, the above-mentioned dispersant and the like have the function of dispersing clay, etc. attached to sintering raw materials such as iron ore, in water, and making it function as a binder. Visitor (lime) sufficiently diffused in the above manner is uniformly dispersed in the obtained pseudo-granules, and during sintering, 5i0
It reacts easily and quickly with the sintered ore and penetrates evenly into the sintered ore, leading to improved strength and productivity of the sintered ore. In any case, the present invention uses a dispersant and/or surfactant, which have never been used in the past for pseudo-granulation of this type of sintering raw material, to easily produce pseudo-nucleated crystals having the above-mentioned excellent properties. It is something that can be obtained, and its practical value is enormous.

As the dispersant and/or surfactant used in the present invention, any of the various conventionally known ones can be used, provided that the clay adhering to lime and iron ore can be dispersed in water. . Typical examples of substances used as dispersants include acrylic acid polymers, acrylic acid-methyl acrylate copolymers, acrylic acid-methyl acrylate-methyl acrylate copolymers, and maleic acid. - Nα, K, MHI4 salts and amide of isodate copolymer, styrecysulfosic acid polymer, acrylate styrecysulfosic acid copolymer (average molecular weight 2
000-2-0000), vinyl diridinium polymer (
average molecular weight 1000-5000), vinylimitasoline polymer (average molecular weight 1500-7000), phosphosic acid (specifically 2-phosphono-1,2,4-)licarbosic acid, aminotrimethylenephosphosic acid, 1- Typical examples of fatty acids (C
Engineering 2. ,,□8), higher alcohol (C8~2゜) sulfuric ester, al+ru (C□.~□5) bent! Cisulfosic acid, Al (C3-4) naphthalene sulfosic acid, naphthalene sulfonic acid formalin condensate, sialyl sulfosuccinic acid, Nα of polyoxysilyl sulfosulfate,
K or NJIt, i, Poliochemistry + Ru (C
□. ~2゜) Ether (HLBB or higher), polyester (C8-9) phenol ether (II
L B 7 or more), polyoxyethylene solpitacyl fatty acid ester (HLB 10 or more), polio+thiethylene solpitacyl (C□2-.8) ester (HLB 8 or more)
, 100 ethylene oxide + 100 ethylene oxide polymer (average molecular weight 1000 to +0000).

The above-mentioned dispersant and surfactant are added to the water used for pseudo-granulation of the sintering raw material in an amount such that the concentration of the dispersant is 0.01-1.0% by weight, preferably around 0.1ffi. The surfactant is 0.001 to 0.1% by weight, preferably 0.0%
Each of them can be used alone or in combination in an amount to give a concentration of about 1% by weight, and the desired effect of the invention can be achieved. In particular, it is preferable to use both drugs together. When the concentration of each drug used is lower than the above range, it is difficult to express the effect of using a second grade drug. Further, if it is used beyond the above range, there is no particular adverse effect, but no improvement in the effect is seen and it is not economical.

The method of the present invention is basically a known method of pseudo-granulation (granulation), except that water containing a dispersant and/or surfactant at the above-mentioned specific concentration is used for pseudo-granulation of the sintering raw material. This can be done by the same means as. In particular, even if the amount of lime used as a bisitor is reduced to less than % compared to the conventional one, the same productivity and yield of sintered ore can be maintained, and therefore the amount of lime used can be reduced, which means resource conservation. It is useful and has the advantage of reducing product costs. Of course, when the amount of lime is kept at the same level as before, sintered products can be obtained with even higher productivity and yield. The method of the invention can also reduce the amount of water normally used, thereby saving energy during sintering.

Next, the present invention will be explained in detail with reference to experimental examples. Note that the dimensions on each side are based on weight.

Examples: Use ores having the composition shown in Table 1 in appropriate combinations, and quicklime 0.5.1.0.1.5 having the particle size shown in Table 2.
Or water containing 2.0% and an amount of dispersant and surfactant to achieve the specified concentration below (or just the same amount of water for comparison)
was added in an amount of 7% to the above ore, and serpentinite, silica sand, and ]-cus were mixed appropriately so that the finished sintered ore had the composition shown in Table 3. Granulation 1~, this was subjected to the sintering pot test.

Table 1 Table 2 Particle distribution of sample quicklime Table 3 Sintered ore composition (dispersant and surfactant) Sample 1 Acrylic acid sorter/methacrylic acid sinter +
Siethyl styrene/methyl acrylate copolymer 1000 ppm Naphthalene sulfosic acid formalic acid condensate 100 ppm Sample 2 Acrylate styrene sulfo acid copolymer 1000 PPM Sodium lauryl sulfate 1007) P7rL sample 3
Acrylic acid sorta, methacrylic acid and methacrylate + thiethylate and methyl acrylate copolymer +000p7) Non-polyoxylated dilauryl ether + o o p
pm sample 4 2-phosphono 1,2. Imaichi tricarboxylic acid + o o o ppm Thorium dodicylbecizecis sulfosyate + o o pp
m Sample 5 Acrylate/styrene oleyl ether 100P7)
How does the production rate (T/hγ・7+t2) of the resulting sintered ore change as the addition ratio of quicklime changes for each of the above samples (samples 1 to 5) and when only water is used for comparison? Figure 1 shows the results of determining whether the animal turns into an ape. In Figure 1, (1) indicates the use of sample 1, (2) indicates the use of sample 2, (
3) uses sample 3, (4) uses sample 4, (5
) indicates the use of sample 5, and (6) indicates the use of no sample (only water).

From FIG. 1, it is clear that according to the method of the present invention, the production rate of sintered ore can be significantly improved in any case.

Further, in the above test, the yield obtained when Sample 1 was used is shown in FIG. 2. In the figure, (1) shows the results when Sample 1 was used, and (6) shows the results when no sample was added (only water) for comparison.

From FIG. 2, it can be seen that according to the method of the present invention, the yield can be significantly improved as well as the above-mentioned production rate.

Furthermore, the same production rate (T/hr - m") as used for Sample I in the above test was determined. The results were as shown in FIG.

Example The water wettability (water absorption) of the ore surface, which has a significant effect on the pseudo-granulation property of the ore, was tested. That is, water containing the dispersant and surfactant shown in [the above sample] and water not containing the above were used as test water, and various brands of ore were applied to each of the above by the infiltration method (JIS M8.105, etc.). The test was conducted using a method similar to the above. The ore brands used are as follows.

a...Mausitonewmash h...Raw River C...Formecit d...Santa Barbara The results are shown in Figure 4. In Figure 4, (W-1) shows the case where the above ore a was tested in water containing sample 1 (test water), and (a-2) shows the case where the same magnet was tested with sample 1-free water (control water). The cases tested are shown below.

Similarly, (b-1) uses ore slag as the test water, and (b-2)
(C-]) uses ore C as control water, (C-]) uses ore C as test water,
(C-2) uses ore C as control water, (d, -1) uses ore d
(d-2) shows the case in which Ore d was tested in test water, and Ore d was tested in control water.

From Figure 4, the water containing the dispersant and surfactant used in the present invention has a water absorbency (wetting property) for any ore.
It is clear that this significantly improves

Example A granulated product was obtained by mixing 100 parts of the ore shown in Table 4 below with predetermined amounts of limestone, silica stone, and coke and using water containing each additive as a sintering raw material mixture.] 700 mx il
: Sintered ore was produced by sintering with test steel under negative pressure of AO. The results of determining the production rate, sintering time, product yield, and falling strength of the sintered ore products at that time are shown in Table 6 below. For comparison, Table 6 also shows the results using granulated products obtained in the same manner using only water containing no dispersant or surfactant. In this comparative example, since granulation was difficult with the sintering raw material mixture having the composition shown in Table 4, a sintering raw material mixture in which the limestone content was changed to 11 parts was used.

Table 6 From Table 6 above, when using the sintered raw material mixture granulated by the method of the present invention, productivity can be increased by improving the product yield, and quicklime can be reduced, and the amount of water can also be reduced. It turns out that it is very advantageous industrially.

[Brief explanation of drawings]

Figure 1 shows the relationship between quicklime addition ratio and production rate, Figure 2 shows the relationship between quicklime addition ratio and yield, and Figure 3 shows the addition amount of dispersant and surfactant and production rate. FIG. 4 is a diagram showing the results of a water absorption test of various ores. (Above) No. 1, 1 Figure 2 164 - Figure 3 Figure 4 Procedural amendments exported) December 13, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of the case 1988 Patent application No. 160175 No. 2, Name of the invention: Pretreatment method for sintered raw materials 3, Relationship with the person making the amendment Patent applicant: Shin Nippon Manufacturing Co., Ltd. (and 2 others) 4: Agent: 2, Hirano-cho, Higashi-ku, Osaka City 10 Heiwa Building phone number 06-203
-0941 (generation) 5, date of correction order
1-f Spontaneous 6. The number of inventions to be increased by the amendment. As shown in the attached sheet, the description in the amendment is corrected in the following official note. (2) Figures 1 and 1 Correct the three figures in separate sheets. (C and above)

Claims (1)

[Claims] ■ When mixing and humidity controlling the sintering raw materials to make them into pseudo-granules,
．． Dispersant and/or at a concentration of 0 + -1,0% by weight
A method for pretreating sintering raw materials, characterized in that water containing a surfactant at a concentration of 0.001 to 0.1% by weight is used.