JPS61266526A - Manufacture of sintered ore by high temperature firing fuel - Google Patents

Abstract

PURPOSE:To obtain sintered ore at a higher efficiency, by arranging sintering fuel in which heat resisting material is coated on a surface of cokes fines to raise the firing level, into sintering material to raise firing temp. of cokes fines and improving aeration due to reduction of heating zone. CONSTITUTION:Cokes lines after crushing are coated singly or combiningly with heat resisting material such as cement, dolomite, MgO fines by using kneader having coating function such as bag mill. Next, the coating treated cokes fines are arranged uniformly by 2-3% in sintering material composed mainly of e.g. 4% pellet feed, 80% iron ore fines, 10% quick lime. As the result, firing temp. of coated cokes is raised by about 50-100 deg.C compared with conventional cokes fines. In this way, decrease of fuel unit due to increase of combustion efficiency of fuel cokes, improvement of aeration due to reduction of red heating zone, improvements in quality and productivity due to increase of combustion rate, are achieved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing raw materials for iron making by sintering, and in particular to a method for producing raw materials for iron manufacturing by sintering, and in particular, sintering with a reduced length of the sintered red zone in which the ignition temperature is increased by pre-treatment. This invention relates to a method for improving air permeability during sintering using powdered coke.

[Conventional technology]

The combustion of coke, which is the fuel for sintering, is an important factor governing the sintering process, and when the permeability of the raw materials and the blended moisture are constant, the combustion of coke within the sintered layer is It is effective to reduce the width of the red zone, which is determined by the ignition temperature level of the fuel coke.

Previously, no pre-treatment was performed to adjust the ignition temperature level of the sintering fuel coke, and the pre-treatment for sintering fuel coke was to make the particle size of coke fine at the time of coke crushing uniform. , for example, JP-A-59-3511
As described in the publication, it has been proposed to granulate coke powder to improve the sintering efficiency of the coke powder and reduce the fuel consumption rate.

[Problem that the invention seeks to solve]

However, coke powder has the disadvantage that it has poor granulation properties and is difficult to form pseudo particles due to its low bulk specific gravity, and its ignition temperature is low, so it cannot be expected to be effective in reducing the red hot zone.

The present invention was completed in view of the shortcomings in the conventional technology, and provides a method for producing sintered ore with high efficiency by improving the combustion characteristics of coke breeze, particularly by increasing the ignition temperature of fine coke and improving ventilation by reducing the red zone. The purpose is to

[Means for solving problems]

The present invention achieves the above object by coating coke powder with a heat-resistant coating material to raise the ignition temperature, and blending this into the sintering raw material as a sintering fuel.

This coating is achieved by installing a kneading machine with a coating function, such as a bag mill or a pin kneading machine, on the line after crushing the coke, and using the kneading machine as a coating material in the kneading machine.
For example, heat-resistant substances such as cement, dolomite), MgO powder, CaO powder, etc. may be used alone or in combination, and depending on the conditions, some adhesive material may be mixed in.

In addition, in addition to the above, a heat-resistant substance may be made into an aqueous solution and sprayed into the kneader for coating.

The coating thickness of the coke coated in this manner varies depending on the particle size of the coke, with larger particles being coated thicker and smaller particles being coated thinly, with a thickness of about 5 to 300 microns.

The ignition temperature of coated coke is about 50 to 1°C, compared to 700 to 800°C for regular coke.
It is possible to raise the ignition temperature by 0.00°C and change the ignition temperature.

Further, examples of the heat-resistant coating material include the aforementioned cement, dolomite, and MgO powder.

Not limited to CaO powder, any inorganic substance with a high melting point can be used, and the addition location may be within the kneader or in a step before that.

〔Example〕

After crushing the coke produced by lime dry distillation to 8 fi or less, the coke powder is supplied into a bottle kneading machine, and a turbid aqueous solution containing 10% cement powder as a coating material is sprayed into the bottle kneading machine from a nozzle. The coke was kneaded to obtain a coated coke in which the surface of the coke was coated with 5 to 300 μm of cement.

This coating coke was added to a sintering raw material mainly consisting of 4% pellet feed, 80% iron ore powder, and 10% quicklime in two stages, with 2 to 3% evenly mixed and varied in upper and lower layers, and sintered.

As a result, as shown in Table 1, the red zone width is usually 100 to 1
After coating, an improvement effect of width reduction of 5 to 30% was observed.

As a result of this, the ventilation improvement effect was approximately 1 increase in JPU (vegetated air permeability index), which resulted in improved productivity and reduction in fuel consumption.

Table 1 [Effects of the invention] The present invention reduces the fuel consumption rate by increasing the combustion efficiency of fuel coke, improves ventilation by reducing the width of the red zone,
The combustion rate becomes faster, resulting in improved quality and productivity.

Claims (1)

[Claims] 1. The solid fuel for sintering is made of steel by coating the surface of coke powder with a heat-resistant substance to raise the ignition temperature level, and the solid fuel is mixed into the sintering raw material to make the sintering red tropical. A method for producing sintered ore using high-temperature ignition fuel, which is characterized by reducing .