JPH0790649A - Treatment of pickling solution - Google Patents

Abstract

PURPOSE:To prevent the deposition of sludge in a pickling treatment tank, etc., by mixing and ejecting the sludge formed at the time of a pickling treatment of a metallic material together with a treating liquid by an ejector and settling and separating the sludge in a solid separating device. CONSTITUTION:The metallic material such as steel products is subjected to the pickling treatment in a pickling tank 1 and after an overflow liquid is supplied by a flow passage 8 into a circulating tank 2, the liquid is replenished with a fresh liquid to adjust an acid concn.; thereafter, the liquid is returned by a pump 6 through a flow passage 9 into the pickling tank 1. The pickling liquid in the pickling tank 1 is sent through the flow passages 12, 13 to the ejector 18 of the pickling tank 1 or the ejector 18 of the circulating tank 2 and is sent in the state of mixing with the sludge generated during the pickling stage to a tank 3 for separating solid from the liquid, by which the sludge is settled and separated. The clean pickling soln. from which the sludge is separated is returned to the circulating tank 2 through a flow passage 11 and is reused. The settled sludge is discharged into a storage tank 4 by opening a valve 7 at an adequate timing. The deposition of the sludge in the pickling tank 1 and the circulating tank 2 is prevented and the stable pickling treatment of the metallic material is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pickling process capable of preventing sludge from accumulating in an auxiliary equipment such as a pickling tank for metal materials and a circulating tank, and efficiently discharging sludge from the pickling treatment system. The present invention relates to a liquid treatment method.

[0002]

2. Description of the Related Art In general, when a metal material is pickled, the surface scale and the compound consisting of the metal and the acid solution are accumulated as sludge in the pickling tank and in a circulating tank installed as necessary. is there. In particular, when a steel material such as stainless steel is treated with a pickling solution containing hydrofluoric acid, sludge solidifies in the tank, and this cleaning requires a great deal of labor and time (see Japanese Patent Publication No. 55-2476). These cleaning operations can be performed only when the operation is stopped, and it is unavoidable to carry out the human sea tactics.

As a method for removing sludge during operation, a method using a screw conveyor (Japanese Patent Laid-Open No. 58-55) is used.
(See No. 012), and a method of scraping it into a pit groove provided at one end of the tank with a feed member attached to a two-endless chain (see No. 55-53508 of Shokai), and a scraper in the pickling tank. A method of using a settling tank (see Japanese Patent Publication No. 2-10874) is known. However, these methods do not disclose or suggest the method of the present invention described below.

[0004]

SUMMARY OF THE INVENTION The present invention is to provide a treatment method capable of removing sludge outside the pickling treatment system even during operation. A further object of the present invention is to provide a treatment method capable of preventing sludge from accumulating in a pickling tank or a circulation tank as an incidental equipment and efficiently removing sludge.

[0005]

According to the present invention, pickling is performed from an ejector installed at the bottom of a pickling tank for pickling a metal material and, if present, from an ejector installed at the bottom of a circulation tank. The sludge in the pickling solution was suspended by spouting the solution without settling in the above tank, and part of the pickling solution containing suspended sludge was separated into liquid and sludge by a solid-liquid separation device. , A separated substantially sludge-free liquid is circulated as a pickling solution, and the separated sludge is discharged to the outside of the pickling treatment system. Is achieved.

According to the treatment method of the present invention, the sludge is raised by ejecting the pickling solution from the ejector installed at the bottom of the pickling tank and the circulation tank, and the sludge is prevented from accumulating in the tank. . Then, the pickling solution containing sludge is sent to a solid-liquid separation device such as a sedimentation tank for solid-liquid separation, and the separated sludge is discharged to the outside of the system. By setting the amount of sludge discharged to the outside of the system equal to or greater than the amount of sludge generated, the sludge in the pickling treatment system is not accumulated and is kept below a predetermined amount.

The present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a flow according to the method of the present invention,
First, description will be made according to this flow. In the pickling tank 1, for example, a stainless steel plate (not shown) is pickled. The pickling solution overflowing from the pickling tank 1 is supplied to the circulation tank 2 via the flow path 8. The pickling solution in the circulation tank 2 is returned to the pickling tank 1 by the pump 6 via the flow path 9. The circulation tank 2 is for replenishing a new liquid by an apparatus (not shown) to adjust the concentration and amount, or for storing the pickling solution when the liquid in the pickling tank is drained.

On the other hand, the pickling solution in the pickling tank 1 is guided by the pump 5 to the ejector 18 of the pickling tank 1 or the circulation tank 2 through the flow passage 12 and the flow passage 13. Furthermore, the pickling solution in the pickling tank 1 is sent to the settling tank 3 via the flow path 10 for solid-liquid separation. The clean pickling solution which is substantially free of sludge separated in the settling tank 3 is returned to the circulation tank 2 through the flow path 11,
To be reused. Of course, when the circulation tank 2 is not used, this clean pickling solution is directly returned to the pickling tank 1.

The sludge separated and settled in the settling tank 3 is stored in the storage tank 4 by opening the valve 7 at an appropriate time according to the settling amount, and discharged to the outside of the pickling system. By setting the amount of sludge discharged to the outside of the system to be equal to or more than the amount of sludge generated in the pickling tank 1, an increase in the amount of sludge accumulated in the acid pretreatment system is prevented.

FIG. 2 shows the pickling tank 1, the ejector 18 installed at the bottom of the pickling tank 1 and the ejector 18 from the flow path 12.
It is the figure which showed the line which reaches to typically. Several ejectors communicate with the distribution pipe 17, and a plurality of distribution pipes 17 are installed at the bottom of the pickling tank 1. The number of ejectors, the number of distribution pipes, the arrangement of distribution pipes, etc. can be appropriately designed according to the size and shape of the pickling tank 1. The ejecting direction of the ejector is usually an obliquely upward direction, but it can be appropriately changed for the purpose of preventing the accumulation of sludge.

The pickling solution that has passed through the flow passages 12 and 13 by the pump 5 is guided to the distribution pipe 17 through the flow passage 14, the valve 15 and the flow passage 16, and then from the ejector 18 to the pickling tank 1.
It is jetted into the pickling solution inside. When the pickling solution is ejected, the sludge rises and is suspended in the solution, preventing the sludge from settling.

Similar to the pickling tank 1, a distribution pipe and an ejector are installed in the circulation tank 2 to eject the pickling solution from the flow path 13 to prevent sludge accumulation. It is also possible to prevent the accumulation of sludge by installing an ejector in the flow path connecting the pickling tank 1 and the sedimentation tank 3 and the flow path connecting the pickling tank 1 and the circulation tank 2 to eject the pickling solution.

[0013]

According to the sludge treatment method of the present invention,
Sludge can be efficiently removed to the outside of the system even during operation, and it is possible to prevent sludge from accumulating in the pickling tank and the circulation tank.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing method of the present invention.

FIG. 2 is a diagram schematically showing a pickling tank and an ejector installed at the bottom thereof.

[Explanation of Codes] 1 Pickling tank 2 Circulation tank 3 Settling tank 4 Storage tank 5 Pump 6 Pump 7 Valve 8 Flow path 9 Flow path 10 Flow path 11 Flow path 12 Flow path 13 Flow path 14 Flow path 15 Valve 16 Flow path 17 Distribution pipe 18 ejector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Yamamoto 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Shigeru Midorikawa 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Harumasa Muramoto 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Yoshikazu Seino Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture No. 1 Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Seto Hotani 1425-2, Fudoki, Nogami Town, Seagrass County, Wakayama Prefecture

Claims (1)

[Claims] 1. A pickling solution is ejected from an ejector installed at the bottom of a pickling tank for pickling a metal material and, if present, from the ejector installed at the bottom of a circulation tank to remove the pickling solution. The sludge was suspended in the tank without settling, and a part of the pickling solution containing suspended sludge was solid-liquid separated into a liquid and a sludge by a solid-liquid separation device, and the separated substantially sludge was separated. A method for treating a pickling solution, which comprises circulating a liquid not containing the pickling solution and discharging the separated sludge to the outside of the pickling system.