JPS5838494B2 - Manufacturing method of sintered ore - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing sintered ore. This aims to improve granulation properties by increasing the granulation properties, improve air permeability during sintering, and improve the production yield of sintered ore, thereby achieving efficient production of sintered ore.

In producing sintered ore, limestone CaCO3 is added to the blended raw materials consisting of iron source powder particles such as iron ore powder, dalai powder, and recovered dust, and fuel powder particles such as coke powder.
It has been known for a long time that self-soluble sintered ore can be obtained by adding and mixing
It is also generally known that production can be increased by using quicklime CaO instead of limestone.

As a result of detailed practical studies on the method of blending such quicklime into sintering raw materials, the present inventors have found that the granulation properties can be improved by adding hot water or hot water during the mixing and granulation. I learned that it is possible to further increase the productivity of sintered ore.

That is, when compounding and granulating a sintering raw material using quicklime as described above, it is added by setting the temperature condition at least during hydrogranulation to generally 40°C or higher, particularly 50°C or higher. It has been confirmed that the activity of quicklime can be appropriately improved, and that the production rate can be increased by more than 10%, in some cases by around 10%.

The method according to the present invention is different from simply preheating the sintering raw material, and its essence is to utilize the sensible heat of hot water or hot water during the water addition reaction to quicklime.

In other words, even if the VC button of the present invention is used, it is inevitable that the sensible heat of the water sprayed and added to the blended raw materials at room temperature will be taken away by the blended raw materials. Since the amount of water is around 3%, the temperature increase due to the sensible heat of the water in the raw material itself is small, but when water is added to quicklime and it becomes slaked lime [Ca(OH)2], the temperature rise is small. It is clear that the sensible heat of the hot water or warm water added is effectively utilized in the 11- state, and the above-mentioned effects can be accurately obtained.

However, in producing such sintered ore, it is clear that a considerable amount of sensible heat is obtained during the sintering process and during the cooling of the obtained hot sintered ore, and this sensible heat is It is effectively used to obtain hot water such as hot water.

For example, the exhaust air from a sintering cooler that cools sintered ore is hot air at a temperature of about 200 to 400°C, and hot water or boiler blow water obtained by once heat-exchanging the sensible heat of this hot air with industrial water Water or steam is further appropriately mixed with industrial water using an ejector, etc., and added by spraying to obtain the desired hot water or hot water.

That is, some of the equipment specifically adopted by the present inventors for such hot water or hot water adjustment is as shown in FIG. 1.2.

Figure 1 shows a case where hot water is obtained using hot air or exhaust gas sensible heat as described above, and the hot air duct 20
A serpentine pipe 3 is provided through which water passes through a valve 2, and a temperature measuring means 5 is attached to the rear of the outlet valve 4 of the serpentine pipe 3 to measure the outlet temperature. The water is sent to the flow rate regulating valve 1 installed in front of the valve 2 via the setting device 6, and the amount of water supplied to the flexible pipe 3 is adjusted to obtain hot water having a predetermined target temperature, and the equipment is overheated and burnt out. It is designed to prevent such things from happening.

The hot water obtained as described above is once sent to the tank 13 via the ejector 7, but the tank 13 is also provided with another temperature measuring means 9 and a temperature setting device 10. The regulating valve 8 of the industrial water supply pipe to the ejector 7 is adjusted by the devices 9 and 10, so that the temperature in the tank 13 is always kept approximately constant.

As shown in the figure, hot water or hot water at a target temperature is supplied from the tank 13 to the spray mechanism 15 of the sintering raw material mixing mechanism 14 via the pump 11 and the regulating valve 12.

Figure 2 shows a system in which the desired hot water or hot water is obtained by mixing hot water or steam with industrial water.
The structure from the spray mechanism 15 to the spray mechanism 15 is the same as that shown in FIG.
Hot water such as steam or boiler blow water is fed through the tank 13, and the regulating valve 16 is operated by the temperature measuring means 9 and temperature setting device 10 provided in the tank 13. Separately, hot water level detection means 1
7 and a level setting device 18 that is activated based on the detection result, and these devices 17 and 18 operate the regulating valve 8 provided in the industrial water supply pipe to obtain the target water level in the tank 13. It is.

Using various types of hot water or hot water that have been brought to a predetermined temperature by the mechanism described above, specifically, hot water or warm water at different temperatures is used for the quicklime powder granules that are mixed with the iron source powder granules as described above. The relationship between quicklime activity and the water temperature used when hot water is added by spraying is summarized in Figure 3.

In other words, the quicklime activity shown as the vertical axis in Fig. 3 is calculated by dissolving 50S' of quicklime (5M or less) in 1500 cc of distilled water (water temperature 40°C) and measuring the amount that reacted with water in 3 minutes using 4N hydrochloric acid. The activity of quicklime varies depending on the temperature of the water used, and the higher the water temperature, the higher the activity.For example, It was confirmed that the activity was increased by around 50% or more at 50 to 60°C compared to 20°C.

However, when we further investigated the relationship between this and the production rate of sintered ore, the results are shown in Figure 4. As the temperature of added water increases, the production rate of sintered ore improves, and the degree of this increases with the addition of water. The production rate reaches approximately 0.02 T/H- with a temperature increase of 10°C.

When the sintering raw material granulated in this way is charged onto the sintering machine pallet and sintered, the ventilation conditions are very good, so even if the sintering material granulates in this way, the sintering material granulates is placed on the sintering machine pallet and sintered. A uniform ventilation condition is ensured throughout the charging layer, and there are almost no cases of partial ventilation, so that the sintering progresses uniformly and favorably. It was confirmed that the sintering process was stable.

Specific examples of the method of the present invention will be described below.

Example 1 Iron ore powder (less than 5%) 85%, limestone powder (2,83%)
Under the body) 13 buttons and quicklime powder (under 2,83 cabinets)
Sintering raw material (water splash resistance 2.5%) mixed with coke powder (2.83 questions or less) at a ratio of 38 to 2.0%
') was granulated using the method shown in Figure 1, using hot air from a sintered ore cooler to make industrial water hot at 60°C and spraying it at a rate of 307 per ton of blended raw materials. (5rrrrn or more: Section 16.1,
Between 2.83 and 5: 25%, between 1 and 2.83mm: 37
．． 2%, 0.5-1m: 11.9%, 0.25-0.
A granular material having a size of 5.6 mm (5.6 mm, 0.25 mm or less = 4.2 mm) was charged into a known Dwatroyd type sintering machine and sintered.

The obtained sintered ore is cooled in a cooler, then crushed, and then
The production rate of 50m of sintered ore was 1.39.
T/Hrr? Met.

On the other hand, the same sintering compound raw materials as mentioned above were heated at 18℃.
The production rate of granules granulated with industrial water at room temperature and sintered in the same manner is 1.30 T/H? ? It is Z2,
According to the present invention o, o 87 T/H? It was confirmed that the production rate of 7Z” was improved.

Example 2 Iron ore powder (5 rice or less) Section 73, Dalai powder (1 question or less)
Article 6.6, the ratio of converter dust (0.25% or less) 5 parts, limestone powder 13.9%, quicklime powder 1.5 parts was mixed with coke powder 3. The mixture was added and mixed at a ratio of 1.9 to 9.30 g of hot water heated to 80 to 81 DEG C. per ton of blended raw materials was sprinkled on the mixture according to the method shown in FIG.

The above material was sintered in the same manner as in Example 1, cooled in a cooler, and then crushed to a size of 5 to 50 mm.
The production rate is 1.43T/Hrr?
Met.

On the other hand, if the same mixed raw materials were granulated using room temperature industrial water at 20°C and similarly sintered → cooled → crushed, the production rate would be 1.31 T/H? ? 22, and it was found that the product according to the present invention improved the production rate by nearly 10 times.

When using the method of the present invention as explained above, the activity of the mixed quicklime is increased by heating it when sintering the granulated material using quicklime as a mixed raw material to obtain sintered ore. This invention can easily improve the production rate of sintered ore, and is highly effective in producing this type of sintered ore.

[Brief explanation of drawings]

The drawings show the technical contents of the present invention. Figures 1 and 2 are explanatory diagrams showing an outline of equipment for obtaining hot water used in the present invention, and Figure 3 is an illustration showing the activity of quicklime. Figure 4 is a diagram showing the influence of water temperature on sintered ore and the relationship between the production rate of sintered ore and the temperature of water added during granulation. However, in these drawings, 3 is a hot air or exhaust gas duct, 5 and 10 are temperature measurement mechanisms, 6 is a temperature setting device, and 7/I'i
Ejector, 11 is a pump, 14 is a sintering raw material mixing mechanism,
Reference numeral 15 indicates a spray mechanism.

Claims (1)

[Claims] 1. A method for producing sintered ore, which comprises adding hot water or hot water at least during the mixing and granulation process when quicklime is mixed and granulated using quicklime as a mixed raw material and sintered.