JPH0474829A - Preliminary treatment of sintering raw material - Google Patents

Abstract

PURPOSE:To pelletize sintering raw materials to a good condition and to improve the quality and productivity of products by dividing the sintering raw materials to a main raw material group and other groups, pelletizing the other groups with quicklime, etc., as a binder, then adding pulverized coke to the pellets to coat the pellets with the coke and further mixing such pellets with the main raw material group and pelletizing the mixture. CONSTITUTION:Other raw material group (b) of limestone, scale, quicklime, and pulverized ore (pellet feed), etc., is fed out of respective hoppers 1 onto a belt conveyor 2 and water is sprayed to these materials by a water spraying device 5, then the mixture is pelletized by a primary mixer 3 to form the pellets 7 in a line B. Further, the pulverized coke 8 fed out of a pulverized coke hopper 6 is clad around the pellets 7 by means of a secondary mixer 4. The main raw material group (a) consisting of iron ore, coke, etc., is fed out of the respective hoppers 1 onto the belt conveyor 2 and is mixed in the primary mixer 3 in a line A. The mixture is then mixed with the pellets 7 coated with the pulverized coke 8 of the line B and after the water is sprayed thereto by the water spraying device 5, the mixture is pelletized by a secondary mixer 4 to obtain the pellets.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for pre-treating sintering raw materials when mixing and granulating sintering raw materials.

[Prior art]

Sintering is the most widely used method for producing blast furnace charge materials today. In the sintering method, sintering raw materials such as iron ore, limestone, return ore, and coke are generally mixed and granulated in advance to improve the quality and productivity of the sintered ore.

FIG. 3 is a schematic diagram showing the conventional pre-processing process of mixing and granulating sintering raw materials.
... are cut out onto the belt conveyor 2, mixed in the primary mixer 3, and conveyed to the secondary mixer 4. Water is added to the raw material from the water injection device 5 during this conveyance or near the entrance of the secondary mixer 4, and the raw material is granulated by the secondary mixer 4 to form a granulated product. In this way, conventionally, the primary mixer 3
The raw materials were mixed in the secondary mixer 4, and the secondary mixer 4 was responsible for granulating the mixed raw materials.

[Problems to be solved by this invention]

However, if the sintering raw material contains a large amount of fine ore raw material such as pellet feed, or if it contains a large amount of sintering raw material with poor granulation properties, the raw material cannot be granulated sufficiently. There is a problem.

This invention was developed in view of the above-mentioned problems, and its purpose is to maintain a good granulation state of the sintered raw material regardless of the increase in the amount of fine ore raw materials such as pellet feed, thereby improving the quality and productivity of finished products. An object of the present invention is to provide a method for pre-processing sintering raw materials that can be improved.

[Means to solve the problem]

This pre-processing method of sintering raw materials is a pre-processing method of mixing and granulating the sintering raw materials, and the sintering raw materials are separated into main raw material groups such as iron ore and coke, and other groups such as binders such as quicklime and fine ore. Before mixing and granulating the main raw material group and the other group, the other group is granulated with a binder such as quicklime, and then fine coke is added and coated around the granules of the other group. . Furthermore, this is mixed with the main raw materials and granulated. This improves the granulation state of the sintered raw material.

As shown in Fig. 1, the granulation process of this pretreatment method consists of hoppers 1, 1, ..., belt conveyor 2 installed on the upstream side.
, a system B consisting of a water injection device 5, a primary mixer 3, a secondary mixer 4, and a fine coke hopper 6, and hoppers 1 and 1° provided downstream thereof, and a belt conveyor 2.1.
It consists of a system A consisting of a secondary mixer 3, a water injection device 5, and a secondary mixer 4.

In lineage B, limestone, Schenobe quicklime and fine ore (
Pellet feed) and other raw materials are cut out onto the belt conveyor 2 from separate hoppers 1, 1, . Create body 7. Furthermore, the fine coke 8 cut from the fine coke hopper 6 is coated around the granules 7 in the secondary mixer 4 .

In system A, main raw material group a consists of iron ore, coke, etc.
are placed in separate hoppers 1, 1. ... is cut out onto the belt conveyor 2, mixed in the primary mixer 3, mixed with the granules 7 coated with the fine coke 8 from the secondary mixer 4 of system B, and then mixed in the water injection device 5. After pouring water, the mixture is granulated using a secondary mixer 4 to obtain a granulated product.

At this time, the other raw materials treated in system B range from 5 to 50% of the total sintered raw materials. In system B, limestone, scale, fine ore, etc. with poor granulation properties are granulated using quicklime as a binder, and the granules are coated with fine coke 8 to form granules 7.

In system A, the main raw materials are added, mixed and granulated in the presence of a large amount of granules 7.

[For production]

This method of pre-processing sintered raw materials can maintain granulation properties even if there is a large amount of fine ore, and can maintain productivity of sintered ore. In addition, since the granules have a double structure and the coke is placed on the outside, they have good sinterability, and the yield and strength of the sintered product can be maintained.

Further, by adding and coating the granules in system B with fine coke, the coke combustion efficiency increases, contributing to a reduction in the basic unit of coke breeze, and at the same time reducing NOx.

〔Example〕

■ Table 1 shows the quality of the finished product made by granulating the sintering raw material containing 5% pellet feed and 1% quicklime.

First, the surface quality is improved by improving the RDI due to the uneven distribution of lime components, and the T
I. Yield also tends to improve as the coke is placed on the outside, preventing the decline in strength and yield that normally occurs when increasing production.

Furthermore, by adding and coating the granules in system B with fine coke, RDI, TI, and yield were all improved compared to the case of using only aqueous water in FIG.

(2) The relationship between the amount of pellet phyto (PF) blended and the production rate when using products granulated by the present method (example) and the current method (comparative example) was as shown in the graph of FIG. 2. It was confirmed that according to the present invention, the production rate is improved compared to the current method, and that the effect of improving productivity increases as the amount of pellet feed and quicklime (BL) increases.

〔Effect of the invention〕

As mentioned above, this invention divides the sintering raw material into the main raw material group and the other group, and after granulating the other group with quicklime etc. as a binder, fine coke is added and coated to this granulated body, and then this Since the sintered raw materials are mixed and granulated with the main raw material group, the granulation state of the sintered raw materials is made good, and the quality and productivity of the finished product can be improved.

Furthermore, by adding and coating the other groups of granules with fine coke, the coke combustion efficiency can be increased, contributing to a reduction in the basic unit of coke powder, and at the same time reducing NOx.

[Brief explanation of the drawing]

Figure 1 is a granulation process diagram of the pre-treatment method of the present invention, Figure 2 is a correlation graph between pellet feed blending amount and production rate showing the results of the example, and Figure 3 is the conventional pre-treatment of sintering raw materials. It is a granulation process diagram of the method. 1... Hopper 2... Belt conveyor, 3... Primary mixer, 4... Secondary mixer, 5... Water injection device, 6... Fine coke hopper, 7... Granules, 8... Fine coke.

Claims (1)

[Claims] (1) In the pre-treatment method of mixing and granulating sintering raw materials, the sintering raw materials are divided into main raw material groups such as iron ore and coke, and other groups such as binders such as quicklime and fine ore, and the main raw material groups are Prior to mixing and granulating the other group, the other group is granulated using quicklime etc. as a binder, and then fine coke is added to cover the granules of the other group with fine coke, and this is then further granulated. A method for pre-processing sintering raw materials, characterized by mixing and granulating them with a group of main raw materials.