JPH0774400B2 - Sintered ore manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is directed to the production of a sintered ore in which limestone powder is charged on a sintering raw material layer of a sinter machine pallet to obtain quick lime by firing and sintering. It is about the method.

<Prior Art> A schematic diagram of a sintering operation is shown in FIG. The raw material 2 cut out from the feed hopper 4 is stacked and supplied on the floor bed ore cut out from the floor hopper 3 onto the pallet 1. The raw material 2 is ignited by the igniter 15 and the powder coke in the raw material is burned by the ventilation of the main blower 14, and the raw material 2 is calcined into a sintered ore. After the sinter ore is crushed by the crusher 5 and cooled by the cooler 6,
It is classified by the sieve 7. Products with a particle size of 8 to 16 mm on the sieve are bed mats.
It is returned to the bedding hopper 3 as 10 and the rest is conveyed to the blast furnace as a product 13. The classified particles having a particle size of -5 mm or less are returned to the ore hopper 4 after being mixed with the new raw material 12 by the mixer 8 as the return ore 11.

By the way, generally, as a means for improving the air permeability of the raw material 2 on the pallet, a binder may be mixed into the raw material. Commonly used quick lime (CaO) is often used as a binder.

As a method for inexpensively producing and utilizing this CaO, Japanese Patent Laid-Open No.
-133331 discloses lime (CaO) powder 9 in a lime hopper 19
A method has been proposed in which the lime powder is cut out by the above method, laminated on the uppermost part of the raw material 2, lime powder is converted to quick lime powder (CaO) by the heat in the ignition device 15, and the lime powder is recovered together with the return ore 11 by the sieve 7 and used as a binder.

However, in this method, (1) the separation of the product 13 and the return ore 11 on the sieve 7 is not complete, and the binder is mixed in the product 13.

(2) A part of the manufactured binder is scattered by the ventilation cooling by the cooler 6.

There is a problem such as.

Therefore, in Japanese Patent Laid-Open No. 147023/1991, a method is proposed in which on the pallet in the vicinity of the mine ore section, quick lime powder is sucked and collected by a scraper, a blower, etc. by utilizing the magnitude of specific gravity of preliminarily calcined lime to increase the recovery yield. Has been done.

However, since the above recovery method is recovery in the vicinity of the mine ore section, the ore is fired while the quicklime powder is stacked in the upper layer between the mine section and the mine section, which reduces the productivity of the sinter. It was

<Problems to be Solved by the Invention> In the present invention, limestone powder mixed with powder coke is charged in the uppermost layer of a raw material on a sinter machine pallet, and heated and ignited in an ignition furnace to produce quicklime powder and sinter. It is an object of the present invention to provide a method for producing a sinter that enables the productivity of the sinter and the unit of coke to be improved.

<Means for Solving the Problems> In the present invention, limestone powder mixed with powder coke is charged in the uppermost layer of a raw material on a sinter machine pallet, and heated and ignited in an ignition furnace to produce quicklime powder and sinter. In the method for producing a sintered ore, the temperature of the quicklime powder generated on the pallet is measured, the position of the pallet at which the temperature of the quicklime powder is equal to or lower than the heat resistance of the recovery facility is found, and the temperature is generated at that position. It is a method for producing a sinter, characterized in that quicklime powder is removed and recovered from the uppermost layer of the pallet.

<Operation> An example of a device configuration for carrying out the present invention is shown in FIG.

A limestone hopper 19 is installed between the mining hopper 4 and the ignition device 15. Limestone hopper 19 and limestone powder 9 and powder coke 18
Are mixed and charged, and the limestone hopper 19 is stacked on the raw material 2 and cut out. It is ignited by the ignition device 15, the coke powder is burned, and the limestone powder is thermally decomposed into limestone (CaO).

A trolley-type mobile recovery hood 21 is installed in front of the ignition furnace. A thermometer 22 is attached to the tip of the hood to measure the temperature of the upper and lower cormorants of quicklime, and the movable recovery hood 21 is moved via the controller 23 on the rail 24 to a target predetermined temperature location. Let In other words, the change of the optimum point for collecting quicklime on the pallet due to changes in the coke mixture ratio to limestone powder and changes in the ignition heat of the ignition furnace is used to optimize the mobile recovery hood while continuously measuring the temperature of quicklime with a thermometer. It is a mechanism to move to. 27 is a scraper, 26 is a suction blower, and 25 is a hopper.

The optimum recovery point is the time when limestone has been transformed into quick lime, but the earlier the better, but usually, the point when the temperature of the quick lime powder falls below the heat resistance of the recovery facility after the burning of the powder coke is completed. Good.

Therefore, in the method of the present invention, the layer of quicklime powder generated in the uppermost layer of the pallet is promptly removed, so that the inhibition of air passage by the quicklime powder layer is minimized,
When compared with the conventional method of collecting just before the mine section,
The thickness of the raw material layer can be increased correspondingly, and the coke unit consumption can be reduced.

Next, the present invention will be described in more detail based on examples.

<Example> Sintered ore production 6700-6900 (dry-t / day), new raw material usage (excluding coke, bedding, and return ore) 7200-7500 (dry-t)
/ day) DL type sintering machine, the conventional method (recovery immediately before the mine ore) and the method of the present invention Quicklime layer surface temperature 10
Recovery at 0 ° C.) was performed.

The particle size distribution of limestone and its components, and the particle size distribution of coke are as shown in Table-1, Table-2 and Table-3.

The top layer of the sinter machine pallet was charged with limestone powder with a coke powder content of 12.5% in a layer thickness of 50 mm.

And the surface temperature of limestone by the ignition furnace was maintained at 1100 ℃.

In the present invention, the quick recovery temperature of the calcined quick lime is set to 100 ° C. in order to quickly recover quick lime. The quick lime recovery position in this experiment was 4 to 6 m from the ignition furnace.

The results are shown in FIG.

In the present invention, compared with the conventional method, the raw material layer thickness can be increased by 20 mm, and the unit of coke is 0.7 kg per ton of sintered ore.
It was possible to reduce.

<Effects of the Invention> A process of charging powder coke and limestone powder into the uppermost layer of a sinter machine pallet, firing limestone by heat in an ignition furnace, and sucking and recovering the quicklime powder in the surface layer. By measuring the temperature, the retention time of quicklime on the pallet was set to the minimum required time, and the air permeability of the raw material layer after recovery was improved, and the raw material layer thickness was increased in advance by that amount. be able to. The unit of coke per ton of sintered ore can be reduced, and the cost of the sintering process can be significantly reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a sintering operation, FIG. 2 is an explanatory diagram of a specific structure for carrying out the present invention, and FIG. 3 is a sintering raw material layer of the present invention and a conventional method. It is a graph which shows the influence which it has on thickness and a basic unit of coke. 1 ... Pallet, 2 ... Raw material, 3 ... Bedding hopper, 4 ... Mining hopper, 5 ... Crusher, 6 ... Cooler, 7 ... Sieve, 8 ... Mixer, 9 ... Limestone Powder + powder coke, 10 …… bed ore, 11 …… return ore, 12 …… new raw material, 13 …… product, 14 …… blower, 15 …… igniter, 19 …… limestone hopper, 20 …… Heat-resistant hoses, 21-movable collection hood, 22-thermometer, 23-controller, 24-rail, 25-hopper, 26-suction blower, 27-scraper.

Front page continuation (72) Inventor Shiro Yasuda No. 1 Kawasaki-cho, Chiba City, Chiba Prefecture Inside the Chiba Works, Kawasaki Steel Co., Ltd. (56) References JP 63-247315 (JP, A) JP 1-147023 ( JP, A)

Claims (1)

[Claims] 1. A method for producing a sintered ore in which limestone powder mixed with powder coke is charged in the uppermost layer of a raw material on a sinter machine pallet and heated and ignited in an ignition furnace to produce quick lime powder and sintering. In, the temperature of the quicklime powder generated on the pallet is measured, the position of the pallet at which the temperature of the quicklime powder is lower than the heat resistance of the recovery facility is found, and the quicklime powder generated at that position is removed from the top layer of the pallet. A method for producing a sinter, comprising recovering.