JPS59221588A - Method and device for manufacturing quenched solidified 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 [Technical Field of the Invention] The present invention relates to a method and apparatus for producing rapidly solidified slag by rapidly cooling molten slag such as blast furnace slag.

[Technical background of the invention and its problems]

This type of rapidly solidified slag is used as a raw material for cement, etc. Conventionally, its production relied on the granulation method shown in Figure 1. In other words, molten slag from a blast furnace, etc. was made to flow down to the main stream gutter 2 through the molten slag gutter 1, and a high pressure installed at the upper end of the main stream gutter 2 was used. From the porous water nozzle 3 for water spouting, approximately 10 times the weight of water to the slag is jetted out, and the molten slag is brought into contact with water in the main gutter 2 to atomize the molten slag and rapidly cool it to form a highly glassy material. Get a slug. Then, this slag is transferred from the main gutter 2 to the stirring tank 4 in a turbid state with the jet water, where it is stirred and homogenized, and then pumped into the dehydration tank 6 by the slurry pump 5 for dewatering, storage and storage. 7 is a water tank 0 However, as it is, the rapidly cooled and solidified slag to be shipped contains a moisture content of a factor of 10, so it cannot be used directly as a raw material for cement.

Therefore, in order to use it as a cement raw material, it must be dried to a moisture content of 2% or less. For this drying, a rotary dryer or an agitating dryer is used, and in that case, the amount of drying heat reaches about 80,000/1 tnh of slag.

On the other hand, since molten slag retains a large amount of heat, it is desirable to recover the heat. However, in the water fracturing method mentioned above,
Since a large amount of water is used, the temperature level of the recovered water is low, and even if we try to recover heat from now on, it will lead to larger equipment, and the operating cost will be high9, and it will not be balanced with the amount of heat that can be recovered. The reality is that effective heat recovery is not carried out for these reasons.

[Purpose of the invention]

The present invention solves the above-mentioned conventional problems all at once.
The purpose of this is that by using molten metal instead of conventional water cooling, it is possible to sufficiently obtain rapidly solidified slag of the desired quality, downsize processing equipment, and heat recovery. It is an object of the present invention to provide a method and apparatus for producing rapidly solidified slag, which is extremely easy to produce, and in which the molten metal used can be easily separated from the slag and recycled.

[Summary of the invention]

The method of the present invention for achieving this object has a temperature lower than the melting point of the molten slag with respect to the discharge stream of the molten slag,
The structure is such that the molten slag is rapidly cooled by bringing it into contact with a quenching molten metal having a large specific gravity.

Furthermore, the apparatus of the present invention is provided with a molten metal injection nozzle for quenching toward the molten slag flow around the molten slag gutter, a stationary container provided at the exit position of the molten slag gutter, and a slag/molten metal turbidity in the stationary container. A discharge means for discharging slag from the bottom of the object is provided, and molten metal is extracted from the lower part and returned to the injection nozzle.

Thus, the present invention uses molten metal cooling instead of conventional water cooling. Usually molten slag is about 1
The slag flows down from the slag gutter at a temperature of about 400°C. This molten slag has a melting point of about 1300° C., and is rapidly cooled by projecting a metal having a melting point lower than this melting point onto the molten slag. Further, the specific gravity of molten slag is about 30, whereas the specific gravity of molten metal is about 7 to 11, and the difference in specific gravity is quite large. Therefore, separation using the difference in specific gravity can be easily performed from a suspended melt resulting from rapid cooling. Furthermore, the molten metal obtained through this separation can be reused for rapid cooling, so there is no waste. Furthermore, since the heat exchange temperature range can be widened, for example when PB having a melting point of 327°C is injected at 350°C into a molten slag of about 1400°C, the heat recovery efficiency is excellent.

[Specific examples of the invention]

The present invention will be explained in further detail below.

The molten metal that can be used in the present invention is one that has a melting point lower than the melting point of slag (approximately 1300°C), has a specific gravity different from that of slag, and is not easily oxidized by slag, such as Ag, Cu+ Sn+
Pb or alloys thereof are preferably used.

The amount of molten metal required to rapidly cool the molten slag is about twice the amount of water in the granulation method by weight, and about 115 times the amount of water in the granulation method by volume. Therefore, compared to the conventional water pulverization method, it is possible to significantly reduce the size of the processing equipment.

The degree of granulation of the molten slag is influenced by the kinetic energy when the quenching molten metal is ejected. As mentioned above, the weight of the molten metal for quenching is about twice the amount of water in the granulation method, so the jetting pressure of the molten metal is r times the pressure in the granulation method, that is, about 35~7~. It is enough. In addition, the injection direction should be directed in the direction of flow of the molten slag.The granular slag obtained by quenching and the molten suspension of molten metal for quenching are allowed to stand still in a stationary container and are separated. It is better. As mentioned above, the obtained granular slag has a lower specific gravity than the molten metal for quenching, so it floats on the surface, where it is separated from the molten metal using a screw conveyor or the like and discharged out of the stationary container. As this separation means, in addition to the above-mentioned screw conveyor, a scraping device may be used. The separated and collected granular slag does not contain any moisture and can be used in its sludge state as a raw material for cement.

If necessary, after the static separation, a centrifugation step may be added to remove the molten metal remaining in the solidified slag.

On the other hand, an example of the present invention will be explained with reference to the drawings, in which the melting method is transferred to the lower part of the stationary container.A porous nozzle 10 is provided around the molten slag (channel 1) toward the discharge end, and the molten metal is discharged from there. The molten slag is rapidly cooled by injection.The rapidly cooled solidified slag becomes suspended with the molten metal and flows into the downflow gutter 11.
It flows down into the stationary container 12 from there. Inside the stationary container 12, the solidified slag floats to the surface due to the difference in specific gravity, and the solidified granular slag S is discharged from the discharge port 14 of the stationary container by the screw conveyor 13, while the molten metal M moving downward is It is led to the heat exchanger 15 from the outlet 17 at the bottom of the stationary container 12, where it exchanges heat with water, and the heat recovered as steam is supplied to other utilization equipment, and the molten metal M whose temperature has decreased is sent to the circulation pump. 16 to the multi-hole nozzle 10 for reuse.

〔Example〕

Examples are shown below. The equipment used is shown in Figure 2.

As a metal, it has a melting point of 327°C and a boiling point of 1740°C.

Pb with a specific gravity of 11.3 was used. 20 t/l of molten PB at a temperature of 350°C and a pressure of 5+yI/l is passed through the porous nozzle 10.
The molten blast furnace slag at about 1400° C. flowing down from the gutter 1 at a flow rate of 1 t/mm was atomized.

The solidified slag with a thickness of about 7 mm discharged from the upper part of the stationary container 12 has a temperature of about 400°C, and is a high-vitreous slag (vitreous content of 97 mm) that can be used as a cement raw material.
). The molten PB sent to the heat exchanger 15 from the outlet 17 had a temperature of about 400° C. and a flow rate of 20 tAM. The temperature of the molten metal discharged from the heat exchanger 15 is 35
The temperature is 0°C, and the pressure is increased to 5 degrees by the circulation pump 16.
It was sent to the multi-hole nozzle 10. fL recovered in heat exchanger 15
The fc calorific value was approximately 300 km/ky slag 0. Furthermore, the obtained granular slag contains no moisture at all, and dehydration treatment of the granular slag is unnecessary.

〔Effect of the invention〕

In summary, according to the present invention, processing equipment can be downsized and heat can be recovered effectively. In addition, the obtained slag can be used as a raw material for cement, etc. in terms of quality, and does not require special drying, so there is no need for a drying process.Furthermore, the molten metal can be recycled and reused, so there is no waste.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of equipment for implementing the conventional method, and FIG. 2 is a schematic diagram showing general provisions for implementing the method of the present invention. 1. Slag gutter 10. Porous nozzle 12. Standing container 13. Suffix 1, - conveyor 15. Heat exchanger 16. Circulation pump S. Solidified slag M. Molten metal Figure 1 2 pieces of lees

Claims (2)

[Claims] (1) A method for producing quenched solidified slag, characterized in that the molten slag is cooled by contacting a molten slag discharge stream with a quenching molten metal whose temperature is lower than the melting point of the molten slag and whose specific gravity is lower than that of the molten slag. (2) A molten metal injection nozzle for quenching toward the molten slag flow is provided around the molten slag gutter, a static container is provided at the outlet of the molten slag gutter, and the upper part of the slag/molten metal turbidity in this static container is 1. An apparatus for producing rapidly solidified slag, characterized in that a discharging means for discharging slag is provided, and the molten metal is extracted from the lower part and returned to the injection nozzle.