JPS60248992A - Method of treating molten slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for treating molten slag, which involves cooling and solidifying molten slag generated in a blast furnace, converter, or the like.

[Conventional technology]

Conventional molten slag processing methods include the water slag method in which molten slag is granulated with a fountain, the wind slag method in which molten slag is granulated with an air jet, and
There is also a dry pit method in which the material is discharged into a dry pit, solidified, and then crushed.

However, in the case of the slag method, a large amount of water is required, the equipment is large, and the equipment costs and running costs are high, and a large amount of water vapor mixed with dust is generated, so there are problems in terms of pollution control. Even in the case of the wind slag method, since air is used for crushing and cooling, a large amount of compressed air is required, and measures to prevent dust scattering are required. In addition, in the case of the dry pit method, a large space is required for discharging and cooling the slag, and the cooling water generates yellow water, which causes pollution problems. Furthermore, there are other problems such as the inability to recover heat.

[Problem that the invention seeks to solve]

In view of the above circumstances, the present invention provides a method for processing molten slag that has high cooling efficiency, can reduce the amount of cooling gas, and can promote resource saving, energy saving, and compactness.

[Means for solving problems]

The present invention solves the problems of the prior art described above by bringing a mixed cooling gas of hydrocarbons and steam into contact with molten slag, and cooling and solidifying the molten slag by absorbing heat from hydrocarbon decomposition and/or reforming. It is something to do.

〔Example〕

A molten slag solidification apparatus preferable for carrying out the present invention will be described below.

The figure shows the molten slag solidification device (1), in which the molten slag receiver (3) is placed below the outlet of the blast furnace (2).
A crushing chamber (5) for crushing the molten slag (4), a gate (7) for appropriately cutting out the crushed solidified high-temperature slag (6), and a sealing device (8) for sealing the area below the gate (7) from the atmosphere. )
It is mainly composed of. The molten slag receiver (3) is
an outlet sole portion (9) extending downward from the lower part;
A vertically movable stopper (10) is provided to stop the outlet sol section (9) at the end of the operation.・Multiple slag outflow holes 0υ are formed.

The crushing chamber (5) surrounds the outer periphery of a plurality of slag flows flowing down from the outlet seal part (9) and the slag outflow hole (11), and its lower end extends to an appropriate position within the crushing chamber (5). It is equipped with a cylinder (+4) to which a mixed gas discharge pipe α (to) for discharging mixed gas (+2) is connected to the upper end.
) through the side wall and inject cooling gas (151) into the crushing chamber (5)
A cooling gas (air-crushed gas) inlet pipe (lbl) is provided to blow in the slag gas, and a cone aD having a conical upper surface for receiving the slag flow and guiding the slag flow is provided at a lower position at the lower end of the cylinder α. Furthermore, cooling gas (1
A nozzle a is provided for blowing up the cone 51 toward the outer circumference of the cone α force.

A cooling plate (a) equipped with a cooling pipe (11) for passing water into the inner peripheral wall that defines the blasting chamber (5) is provided.
is provided. The cooling plate (2o) consists of a cylindrical center plate (2) provided along the inner peripheral wall of the blasting chamber (5) and a central disk (2υ) extending inward from the upper end of the blasting chamber (5). It is composed of a flange-shaped upper plate (2) and a truncated conical cylinder-shaped lower plate (c) whose diameter is gradually reduced downward from the lower end of the center plate CD.

A sealing device (8) is provided with a gate (7) located below the crushing chamber (5).
), a seal body (26) that performs a water seal by immersing the water seal ring 0 (a) into water in the water reservoir (c), and a seal body. (2
6) to raise and lower the sole body 06)/linda (2)
It consists of a trolley (c) equipped with η.

The cooling gas (151 is a mixture of hydrocarbons or similar compounds and water vapor), and the cooling gas C151 is ejected into the blasting chamber (5) from the nozzle mark A through the cooling gas introduction pipe (161).

On the other hand, the molten slag (4) flows into the molten slag receiver (3) through the tap pipe (2). The molten slag (4) at about 1500°C that has flowed into the molten slag receiver (3) flows into the outlet seal part (
9) From the slag outflow hole aυ at the lower end, the slag is divided into a plurality of streams and flows down onto the cone αη. The molten slag (4), which has become a conical cylinder-shaped flow on the cone α force, is crushed by the cooling gas a jetted from the nozzle 0 frame as it flows down from the outer periphery of the cone aη, and is blown up. It will be done.

Molten slag (
4) comes into contact with the upper plate @ of the cooling plate (A), is rotated downward at the upper plate 0z, dives into the center plate (2υ) and flows down, and then slides down the lower plate (C), where it is cooled and solidified to approximately The particles become solidified high temperature slag (6) at 800°C and accumulate in the lower part of the blasting chamber (5).

The cooling gas (151) ejected from the nozzle a8 becomes hot when the molten slag (4) is crushed and rises in the circle ma4, and the hydrocarbons in the cooling gas are thermally decomposed into lower-grade hydrocarbons. However, by selecting treatment conditions, hydrogen and carbon oxide can also be produced by a steam reforming reaction.

The reason why the cooling gas contains water vapor is to prevent the condensation polymerization of hydrocarbons and the formation of carbonaceous substances, and some of it may also be used in the steam reforming reaction. be.

Mixed gas a of water vapor and produced gas, which is a lower hydrocarbon
7J is discharged from the discharge pipe α tank, and the generated gas is used as a raw material such as polyethylene, reducing gas, or fuel.

The thermal decomposition of the hydrocarbons is a violent endothermic reaction, and the reaction rate is fast, making it possible to rapidly cool the molten slag in a short period of time, and to greatly reduce the amount of cooling gas used.

That is, CaOlMgO exists in the slag and acts as an effective catalyst for steam reforming of hydrocarbons, so that the reaction rate is fast (the reaction is completed in a few seconds or less). Therefore, the cooling capacity is increased, the operating cost is reduced, the volume of the equipment is small, the equipment can be made smaller, and heavy hydrocarbons such as tar can be used, and the temperature is as low as 500 to 600°C. It can be used for reactions up to a wide range.

When an appropriate amount of solidified high-temperature slag (6) has accumulated in the crushing chamber (5), the seal body (20) is lowered by the cylinder (27) to horizontally move the trolley egl, and then the gate (force) is opened and the solidified high-temperature slag is removed. Cut out (6).

Examples of hydrocarbons include naphtha, kerosene, light oil, residual oil, tar extracted from coke ovens, and light oil.

Furthermore, if there are ungasified components in the produced gas or if it is desired to change the gas composition, this gas can be passed through a catalyst tank to react with water vapor and hydrocarbons to obtain a gas with the desired composition.

〔Effect of the invention〕

As described above, the present invention exhibits the following excellent effects.

(1) Since thermal decomposition of hydrocarbons or endothermic heat generated by thermal decomposition and steam reforming is utilized, the cooling effect is high, allowing rapid cooling and increasing cooling capacity.

(11) Since not only sensible heat but also decomposition or decomposition/reforming endothermic reactions are utilized, the amount of cooling gas in the cooling tank can be significantly reduced.

0ii) A closed system can be easily realized with a small amount of cooling gas, and dust and water vapor can be prevented from dispersing into the atmosphere.

(1v) Since hardly any carbon particles are generated, carbon particles are likely to be mixed into the slag.

M The heat and sensible heat of molten slag can be recovered as reaction heat, so energy usage efficiency is high.

[Brief explanation of drawings]

The figure is an explanatory diagram of a molten slag solidification apparatus suitable for carrying out the present invention. (4) indicates the molten slag, (5) indicates the crushing chamber, and aS indicates the cooling gas.

Claims (1)

[Claims] 1) A method for treating molten slag, which comprises bringing a mixed cooling gas of hydrocarbons and steam into contact with the molten slag, and cooling and solidifying the molten slag by heat absorption from decomposition of the hydrocarbons and/or steam reforming.