JPS59100228A - Manufacture of sintered ore - Google Patents

Abstract

PURPOSE:To obtain homogeneous sintered ore by charging starting materials in two layers onto the pallet of a Dwight-Lloyd type sintering machine from two discharge outlets attached to a starting material hopper to reduce the grain size of the starting material layers in the thickness direction and segregation in the composition. CONSTITUTION:Two drum feeders 2, 2 are attached to a starting material hopper 1 so that the feeder 2 for charging starting materials onto a pallet 8 to form an under layer is positioned at a lower level than the feeder 2 for charging starting materials onto the pallet 8 to form an upper layer. Starting materials in the hopper 1 are charged onto the pallet 8 in two layers through each gate 3 and each sloping plate 4. Percolation due to the dropping of starting materials is reduced without considerably altering the present equipment, so the purpose can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing sintered iron ore using a DL (Dwight Lloyd) type sintering machine.

In recent years, in iron ore sintering operations using DL-type sintering machines, technological advances have been made to save energy and improve productivity, and the thickness of the raw material layer charged onto pallets has increased significantly compared to a few years ago. are doing. In this type of sintering operation, when raw materials are charged into the sintering machine, they do not undergo percolation and are deposited on the pallet. On the pallet, heavy and large particles are in the lower layer, and light and small particles are in the upper layer. This results in so-called grain size segregation.

For this reason, segregation of chemical components occurs in the layer thickness direction of the sintered raw material layer due to differences in chemical components depending on the grain size of the raw material, resulting in compositional heterogeneity in the sintered ore as the blast furnace charge. This is the cause of variations in the quality of sintered ore.

When charging raw materials onto pallets during the production of sintered ore, various studies have been conducted to suppress the segregation of grain size and chemical components in the layer thickness direction so that the chemical components are more homogeneous, but there is no definitive solution. has not been obtained. In response to the increasing dispersion of sintered ore quality due to the increase in the thickness of the sintered raw material layer in recent years, the invention was developed to reduce grain size segregation and component segregation in the layer thickness direction without making major modifications to the current equipment, and to create a homogeneous sintered ore. The purpose of this project is to produce sintered ore.

In order to produce homogeneous sintered ore, it is sufficient to prevent segregation that occurs when raw materials are charged into pallets. In general, for example, the thickness of the charging material layer may be divided into several layers to reduce the thickness of the layer charged at one time, thereby shortening the distance at which percolation occurs. Is it possible to achieve this by dividing the raw material into several layers when charging it on a pallet?
Supply equipment was required for the number of layers to be divided, and major equipment modifications were required. The present invention accomplishes the above object by charging the sintering raw material onto a pallet in two stages by providing two discharge ports in the existing raw material hopper without adding additional raw material transportation equipment.

FIG. 1 shows a sectional view of a sintering raw material charging device for carrying out the present invention.

In Fig. 1, 1 is a material pumper, 2.2 is a lower ram feeder, 3.3 is a hopper gate, 4, 4 is a sloping plate, 5. 5 is a charging material, 6 is a bedding ore hopper,
7 shows the bedding ore, and 8 shows the top surface of the sintering machine pallet. In the present invention, two drum feeders are provided in one raw material hopper 1.
- 2 and 2 are installed at different height levels, and the drum feeder that charges raw materials to the lower layer of pallet 8 is located lower than the drum feeder that charges raw materials to the upper layer of the pallet, which prevents percolation due to falling raw materials. Efforts are being made to reduce the occurrence as much as possible. By using such a raw material hopper 1, there is no need to add a transportation system for raw materials to the raw material hopper, and the conventional system can be used as is, and the particle size and chemical component segregation in the layer thickness direction of the raw material layer on the pallet can be avoided. It is possible to significantly reduce the amount of sintered ore and produce sintered ore with stable quality.

Figures 2 and 3 show the segregation of raw materials on pallets in the method of the present invention and in the conventional method.

The upper layer thickness is 350mm and the lower layer thickness is 350mm using the same sintering machine.
Particle size and basicity (CaO/Si
Fig. 2 shows the degree of segregation of o2), and Fig. 3 shows the degree of segregation in the conventional method.

As can be seen from the results in Figures 2 and 3, the average particle size of conventional one-stage charging (when the raw material hopper has one outlet) is 1.9 mm in the top layer and 3.5 mm in the bottom layer. On the other hand, in the method of the present invention, the average particle size of each layer height is about 2 mm for the top layer and about 3 mm for the bottom layer, and the variation in particle size in the layer thickness direction is significantly smaller in the method of the present invention than in the conventional method. I know that there is. Similarly, CaO/SiO
Looking at the distribution of 2, in the case of the conventional method, it is 1.71 in the top layer and 1.49 in the bottom layer, whereas in the method according to the present invention, it is about 1.65 in the top layer and 1.55 in the bottom layer. It can be seen that the variation in CaO/SiO2 in the layer thickness direction is much smaller than in the conventional method and is averaged out.

The production method of the present invention makes it possible to produce sintered ore by reducing the particle size and segregation of chemical components in the layer thickness direction of the raw material layer on the pallet of the DL sintering machine, resulting in homogeneous sintering with less variation in quality. It was possible to produce ore.

4. Detailed explanation of the drawings Fig. 1 is a partial cross-sectional view of a raw material hopper with two discharge ports used in the practice of the present invention, and Figs. 2 and 3 show charging by the inventive method and the conventional method, respectively. 2 is a graph showing the segregation status of the particle size and basicity (CaO/SiO2) of the raw material on the pallet obtained in the layer thickness direction.

Claims (1)

[Claims] 1. In the sintering operation of the DL type sintering machine, two discharge ports are provided in the raw material hopper, and the raw materials in the hopper are charged onto the sintering machine pallet in two stages, upper and lower, and the raw material layer on the pallet is A method for producing sintered ore, characterized by producing sintered ore by reducing segregation in the layer thickness direction.