JPS6199635A - Manufacture of sintered ore - Google Patents

Abstract

PURPOSE:To reduce unit requirements of breeze and to improve cold strength of a sintered ore, by sintering a mixed starting material contg., as a part of the starting materials, the breeze whose water content is reduced to a prescribed proportion by drying. CONSTITUTION:The breeze as fuel is dried so that its water content is reduced to <=8%. This dry breeze is mixed with the starting materials such as iron are powder, limestone powder, return ores, or the like. The resulting mixture is granulated to regulate the mixed starting material. Succeedingly, this mixed starting material is subjected to sintering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing sintered ore, which is a raw material for iron manufacturing.

[Prior art and its problems]

The properties of sintered ore, which is produced by sintering raw materials such as iron ore powder, limestone powder, and return ore, and coke powder as a fuel, and many of the various units during production are , depends on the availability of coke powder, which is the main fuel.

Therefore, in order to improve the permeability of the raw materials during the sintering process and to efficiently produce sintered ore, the above-mentioned raw materials such as iron ore powder, limestone powder, and return ore are mixed with coke powder as a fuel. The resulting mixture is granulated to prepare a mixed raw material, and the granulated mixed raw material is sintered to produce sintered ore.

FIG. 4 is a process diagram showing the above-mentioned conventional mixed raw material preparation process. As shown in the drawing, coke powder cut out from hopper 1, iron ore powder cut out from hopper 2, limestone powder cut out from hopper 3, and limestone powder cut out from hopper 4 are mixed at predetermined ratios. The returned ore is mixed in a second mixer 5.

Next, it is granulated to a predetermined particle size by a secondary mixer 6 to form a mixed raw material.

However, since coke powder normally contains 15% water, the mixed raw material prepared in this way contains K, coke powder 7 as a core, and iron ore surrounding it, as shown in Figure 5. Pseudo particles to which stone powder 8 is attached are generated. If a large number of such pseudo particles are present in the mixed raw material, a problem arises in that the supply of oxygen in the air is insufficient during the sintering process, and the combustion efficiency of the coke powder is reduced.

This results in an increase in various units of sintered ore production, especially coke powder consumption, and the cold strength of the product sintered ore is low, making it necessary to sacrifice productivity in order to maintain cold strength. I had no choice but to do it.

[Purpose of the invention]

Therefore, the object of the present invention is to produce sintered ore by sintering a mixed raw material obtained by granulating a mixture of raw materials such as iron ore powder, limestone powder, return ore, and coke powder as a fuel. Manufacture of sintered ore that is difficult to manufacture, does not cause a reduction in the combustion efficiency of coke powder during the sintering process, reduces the basic unit of coke powder, and can produce sintered ore with high cold strength. The purpose is to provide a method.

[Summary of the invention]

This invention involves preparing a mixed raw material by granulating a mixture of raw materials such as iron ore powder, limestone powder, return ore, and coke powder as a fuel, and producing sintered ore by sintering the mixed raw material. In the method for producing sintered ore, the coke powder is dried prior to granulation to reduce its water content to 8.
The present invention is characterized in that a mixed raw material is prepared from the coke powder whose water content is reduced to less than 100 ml, and the mixed raw material is sintered.

[Structure of the invention]

In this invention, the reason why the coke powder is dried prior to granulation to reduce its moisture to 8% or less is that generally speaking, the moisture that contributes to granulation is limited to only the amount present on the top surface of the particles out of the total moisture. Therefore, by reducing the moisture content of the coke powder, the purpose is to prevent the generation of pseudo particles with the coke powder 7 as a core and the iron ore powder 8 attached around it, as shown in FIG. If the moisture content of coke powder exceeds 8%, the desired effect cannot be obtained.

FIG. 1 is a process diagram showing the process of preparing mixed raw materials in the method of the present invention. As shown in the drawing, the coke powder 6 has its water content reduced to 8% or less in a drying step 9, and the coke powder whose water content has been reduced in this way is stored in a hopper IK.

Next, as in the past, hopper 1 is added at a predetermined ratio.
coke powder with a moisture content of 8% or less cut out from the coke powder, iron ore powder cut out from the hopper 2, limestone powder cut out from the hopper 3, and return ore cut out from the hopper 4, -
The raw materials are mixed in a secondary mixer 5, and then granulated to a predetermined particle size by a secondary mixer 6 to form a mixed raw material.

Figure 2 shows the basic unit of coke powder when sintered using a mixed raw material mixed with coke powder whose moisture content has been reduced to about 4% as described above, compared to the conventional coke powder containing about 15% moisture. It is a graph showing a comparison of the basic unit of coke powder when sintering is performed using a mixed raw material in which coke powder is mixed. As is clear from the drawings, according to the method of the present invention, the coke powder consumption rate could be reduced from about 42/9/T-8v of rice to about 39 Kl'/T-sv-1.

FIG. 3 is a graph similarly showing the cold strength (T, I) of the product sintered ore. As is clear from the drawings, according to the method of the present invention, the cold strength (T, I) of the product sintered ore could be improved from about 65 inches in the conventional method to about 67.3%.

〔Effect of the invention〕

As explained above, according to the disclosed method, a mixed raw material obtained by granulating a mixture of raw materials such as iron ore powder, limestone powder, and return ore and coke powder as a fuel is sintered. When producing sintered ore, it is an industrial method that does not cause a decrease in the combustion efficiency of coke powder during the sintering process, reduces the basic unit of coke powder, and improves the cold strength of sintered ore. It brings about beneficial effects.

[Brief explanation of the drawing]

Fig. 1 is a process diagram showing the preparation process of mixed raw materials in the method of this invention, Fig. 2 is a graph showing the coke powder consumption rate of this inventive method and the conventional method, and Fig. 3 is the product of the inventive method and the conventional method. FIG. 4 is a graph showing the cold strength of sintered ore, FIG. 4 is a process diagram showing a conventional mixed raw material preparation process, and FIG. 5 is a cross-sectional view of pseudo particles. In the drawings, 1.2, 3.4...hopper, 5...-secondary mixer, 16...secondary mixer, 7...
・Coke powder, 8... Iron ore powder, 9... Drying process.

Claims (1)

[Claims] A mixed raw material is prepared by granulating a mixture of raw materials such as iron ore powder, limestone powder, return ore, and coke powder as a fuel, and the mixed raw material is sintered to produce sintered ore. In the method for producing sintered ore, the coke powder is dried prior to granulation to reduce its water content to 8.
% or less, preparing a mixed raw material using coke powder whose moisture content has been reduced in this way, and sintering the mixed raw material.