JPH076005B2 - Method for producing quicklime with a sintering machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing quicklime in the uppermost layer of a sinter machine pallet in a sintering process of a blast furnace raw material using a Dwightroid-type sintering machine. The present invention relates to a method for improving the quality and productivity of quicklime.

<Prior Art> FIG. 2 shows a schematic diagram of a sintering operation of a blast furnace raw material using a Dwightroid type sintering machine. The sintering raw material 2 cut out from the feed hopper 4 is stacked and supplied on the bed ore cut out from the bed mine hopper 3 onto the pallet 1. The raw material 2 is ignited by the igniter 15 and the powder coke in the sintering raw material is burned by the ventilation of the main blower 14, and the sintering raw material is fired to become a sintered ore. The sinter ore is crushed by the crusher 5 and the cooler 6
After being cooled by, it is classified by the sieving machine 7. And the product with a particle size of 8 to 16 mm on the sieve is the bedding ore 10 and the bedding hopper 3
The residue is transported to the blast furnace as product 13. On the other hand, the classified particles having a particle size of -5 mm or less are mixed with the new raw material 12 by the mixer 8 as the return ore 11 and then the ore feeding hopper 4
Returned to.

Now, 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 producing this CaO at low cost, JP-A-58-13333 is used.
In the publication No. 1, lime (CaCO ₃ ) powder particles 9 are cut out from a lime hopper 19 and stacked on top of the raw material 2 to cause the heat in the igniter 15 to perform the reaction of the following formula (1), CaCO ₃ → CaO + CO ₂ + ΔH (1) (ΔH: Enthalpy difference) A method for producing quicklime particles from limestone particles has been proposed.

However, since the dissociation of CO ₂ gradually progresses from the surface of limestone powder particles to the inside, when firing limestone with a wide particle size range, if the aim of firing is to a small grain size, a large grain size is often unfired. However, if aiming at a large particle size, a small particle size would cause over-firing, and there was a problem in production efficiency or quality.

<Problem to be Solved by the Invention> An object of the present invention is to provide a method for producing quick lime having a higher efficiency and a higher quality than ever before in a method for producing quick lime using a sintering step.

<Means for Solving the Problems> That is, according to the present invention, in a sintering process using a Dwightroid type sintering machine, a mixture of limestone powder particles and coke powder is charged in the uppermost layer of the sintering machine pallet. When quicklime particles are produced from limestone particles by the heat in the ignition furnace, the grain size distribution in the height direction of the limestone layer is characterized by the coarse charging on the upper side and the fine charging on the lower side by the vibration type charging device. It is a method of producing quicklime with a binding machine.

<Operation> In the present invention, when the coke powder and the limestone powder particles are charged into the uppermost layer on the sinter machine pallet, the vibration type charging device causes particle size segregation in the height direction of the limestone layer, and the upper layer Since it was charged so that the grain size decreases from the lower part to the lower part, coarse limestone can be charged in the region with the highest heat and fine limestone in the region with the lowest heat, and as a result, limestone Unfired and overfired powder can be greatly reduced.

A specific configuration for performing the above charging is shown in FIG.

A feeder 20 of a limestone hopper 19 cuts out a mixture 9 of coke powder and limestone powder, and a chute 21
A mixture of the limestone powder particles and the coke powder is supplied to the vibration type charging device 22 via the above. The vibrating charging device 22 is configured to arrange the coarse particle group of limestone upward and the fine particle group downward to give vibration to the limestone powder particles. Therefore, at the discharge point of the vibration type charging device, the particle size becomes smaller in order from the top to the bottom with respect to the layer thickness of limestone,
The smaller the particle size, the closer the charge, and the larger the particle size, the farther the charge. As a result, the grain size becomes smaller in the height direction of the limestone layer from the upper layer portion to the lower layer portion.

Next, the present invention will be described in more detail with reference to Examples.

<Examples> Quicklime was produced by charging limestone powder particles into the uppermost layer of a sinter machine pallet by a vibration charging device under the following conditions.

Coke content: 12.5% Layer thickness: 30 mm Limestone surface temperature by ignition furnace: 1050 ℃ Grain size distribution of limestone Vibration type charging device width 3500mm, length 4000mm, frequency 750cpm
It was adopted.

Table 1 shows the results of comparison between the conventional method and the present invention under the above conditions. As is clear from the table, when the present invention is adopted, the decomposition rate of CaCO ₃ is 53% to 67% compared to the conventional method in terms of production.
In terms of quality, quicklime reactivity is 105 to 165 ml.
Has improved.

<Effect of the invention> In the process of charging powder coke and limestone powder particles into the uppermost layer of the sinter machine pallet and firing them, and producing quicklime powder particles from the limestone powder particles by the heat in the ignition furnace, Since the particle size distribution of limestone powder particles in the height direction was controlled by the vibratory charging device, the productivity and product quality of quick lime production could be greatly improved.

Therefore, as compared with the conventional method, it is possible to significantly reduce the cost in the production of quicklime.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for carrying out the present invention, and FIG. 2 is an explanatory view of a sintering operation process. 1 ... Pallet, 2 ... Sintering raw material, 3 ... Floor mat ore hopper, 4 ... Sintering raw material feeding hopper, 5 ... Crusher, 6 ... Cooler, 7 ... Sieving machine, 8 ... … Mixer, 9 …… Mixture of powdered limestone and coke, 10 …… Flat ore, 11 …… Return ore, 12 …… New raw material, 13 …… Product, 14 …… Blower, 15 …… Ignition device , 19 …… Limestone hopper, 20 …… Feeder, 21 …… Chute, 22 …… Vibratory charging device.

Claims (1)

[Claims] 1. In a sintering process using a Dwightroid type sintering machine, a mixture of limestone powder particles and powder coke is charged in the uppermost layer of a sinter machine pallet, and the limestone powder particles are heated by heat in an ignition furnace. A method for producing quicklime in a sintering machine, characterized in that, when producing quicklime powder particles, the grain size distribution in the height direction of a limestone layer is charged coarsely at the top and finely at the bottom by a vibrating charging device.