JPS581052B2 - Mining slag fragmentation and heat recovery method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for fragmenting slag and recovering heat.

Generally, when producing pig iron in a blast furnace, slag called slag is produced due to the action of a solvent when ore is melted, and this slag must be taken out of the blast furnace separately from the pig iron, and its disposal is a major problem. ing.

Conventionally, as shown in FIG. 4, slag 43 accumulated above pig iron 42 at the bottom of a blast furnace 41 is taken out in a molten state as shown by arrow 44 into another container 45 and allowed to cool naturally. Otherwise, the slag was put into water and cooled without any special treatment, so the slag solidified by cooling and became large lumps, which required a lot of effort to handle for subsequent reuse or disposal. In addition to making treatment work extremely difficult, the water was also contaminated.

Further, in such conventional methods, the extremely high heat contained in the molten slag cannot be effectively recovered, and the slag is wasted.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and by recovering slag in the form of fibers, handling such as subsequent reuse and dumping becomes extremely simple and easy. The purpose of this invention is to provide a method for fragmentation and heat recovery of slag that can effectively recover slag.

In order to achieve this objective, the method of the present invention involves directly fragmenting or fiberizing the slag in a molten state using a fragmentation device when it is discharged from a blast furnace into a cooling tower, and solidifying it by cooling with a refrigerant in the cooling tower. The refrigerant is characterized in that it is recovered as fine slag or slag fibers, and that the refrigerant is guided to a suitable heat recovery device after heat recovery.

The present invention will be further described below with reference to the accompanying drawings.

FIG. 1 is a schematic system diagram showing an example of a device used in the present invention.

Hot metal 2 is formed at the bottom of the blast furnace 1, and molten slag 3 is formed above the hot metal 2.

The hot metal 2 is taken out through a take-off pipe 4, and the slag 3 is separately discharged through a discharge pipe 5.

The slag 3 discharged from the discharge pipe 5 is sent into the cooling tower 8. At the tip of the discharge pipe 5, the slag 3 is finely divided into fibers and discharged into the cooling tower 8 as fine slag or slag fibers 9. The slag 3 is discharged in a molten state by gravity through a fragmentation nozzle 7 of this fragmentation device 6 into a cooling tower 8.

The subdivision device 6 of this embodiment has a substantially triangular longitudinal cross-sectional shape, as shown in an enlarged view in FIG.

The cooling tower 8 has an opening 11 at its lowest part that serves as an inlet for air 10, which is a refrigerant, and an outlet for recovering the finely divided slag or slag fibers 9. Or the air 1 that has become high temperature by absorbing heat due to contact with the slag fibers 9
An outlet 12 is provided for conducting the 0 to a heat recovery device (not shown), such as a boiler.

Next, to explain the operation of the present invention, first, the slag 3 in the blast furnace 1 is transferred to the cooling tower 3 while being molten through the discharge pipe 5.
The slag or slag fibers 9 are discharged directly into the cooler 8 by gravity from the fragmentation nozzle 7 of the fragmenter 6 to form fine slag or slag fibers 9, which are then lowered through the cooler 8. .

On the other hand, air 10 for cooling the fine slag or slag fibers 9 and recovering heat is introduced from the opening 11 of the cooling tower 8 and rises inside the cooling tower 8, but at this time, the molten state formed as described above is It comes into contact with the fine slag or slag fibers 9, absorbs heat, cools it, and gradually solidifies while remaining fibrous.

As a result, the fine slag or slag fibers 9 are collected from the opening 11 as shown by the arrow 9a in FIG. 1 in a state where they have lost their adhesive strength, and are discarded or reused. It is possible to use the rock wool fibers as heat insulating materials by compressing them appropriately, and even when discarding them, they can be easily crushed and disposed of in landfills or other forms of disposal.

The air 10 that has absorbed heat from the slag or slag fibers 9 is heated to a temperature of, for example, 1000° C., and is led to a heat recovery device through an outlet 12, where it can be effectively reused as a high-temperature heat source for a boiler or the like. can.

FIG. 3 shows a modification of the subdivision device, and this subdivision device 6
a has a substantially semicircular vertical cross-sectional shape, and the subdividing nozzle 7a
Since a large number of slags or slag fibers 9a are arranged radially, there is an advantage that fine slag or slag fibers 9a can be formed throughout the inside of the cooling tower 8.

As explained above, according to the present invention, by dividing and solidifying the slag into fibers and recovering it, subsequent handling such as reuse and dumping is extremely easy, and labor-saving is achieved. The absorption of heat from this fibrous slag is also extremely efficient, and the recovery and reuse of heat is very effective.

In addition, air, which is the refrigerant used in the present invention, does not actively dissolve impurities from the slag, and there is no need to treat the refrigerant. This is extremely advantageous because there is no room for inconvenient and wasteful operations such as impurities being mixed into the water and the water having to be treated before being discharged.

Furthermore, in the present invention, the slag descends in the cooling tower by gravity, while the air, which is a refrigerant, rises by natural convection, and the slag is cooled and solidified by countercurrent contact. This method has the advantage that no separate power is required to fragment the slag into fine slag or slag fibers.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram showing an example of a device used in the present invention;
FIG. 2 is an enlarged vertical sectional view of a fragmentation device, FIG. 3 is an enlarged vertical sectional view of a modified example of the fragmentation device, and FIG. 4 is an explanatory diagram showing a conventional technique. 1... Blast furnace, 2... Hot metal, 3... Slag, 5... Discharge pipe, 6, 6a... Refinement device, 7, 7a... Refinement nozzle, 8... Cooling tower, 9, 9a... Slag paper or slag fiber, 10
……air.

Claims (1)

[Claims] 1 The slag in the blast furnace is finely divided into fibers in a molten state by gravity and discharged into the cooling tower through a fragmentation nozzle, and is lowered in the cooling tower, and is directed toward the rising air in the cooling tower. A method for fragmentation and heat recovery of slag, which comprises cooling and solidifying the slag by bringing it into contact with a flow, recovering it as fine slag or slag fibers, and recovering heat from the air heated by the contact.