JP2006037218A - Method of removing and cleaning residual waste solution of stainless steel treated surface which does not require rinsing treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method for cleaning a treated surface without depending on a rinsing treatment by taking the nonavailability of facilities of an aqueduct etc., into consideration on an outdoor site while a waste solution fouled by burning of an electrolyte remains after the electrolysis around a weld line of a stainless steel by a manual type electrolyzer. <P>SOLUTION: The residual waste solution on a treated surface is removed and cleaned without rinsing by directly spraying a powder of diatomaceous earth to the treated surface to adsorb the waste solution therein or slightly moistening cloth or paper previously stuck with the powder of the diatomaceous earth with water and bringing the cloth or the paper in this state into abutment on the treated surface to wipe away and to adsorb the waste solution. When using the electrolyte of the acid like in the above, the acid remains in the waste solution and therefore caustic alkali and a neutralizer of a sodium carbonate system are previously mixed in the diatomaceous earth in order to neutralize the acid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, when the stainless steel weld burn is dissolved and removed using a manual electrolysis apparatus, the waste solution of the electrolytic solution remaining on the treated surface is removed, or the cleaning is made of an aqueous solution of organic or inorganic salts or acids. In the process of removing the waste liquid of the cleaning agent remaining on the treated surface after removing rust and dirt on the stainless steel surface with an agent, inconvenience associated with the removal treatment by water washing, which was the only and indispensable removal method in the past, such as water supply Provides a new treatment method that effectively removes the waste liquid and obtains a clean surface without relying on the water washing process, exceeding the condition that there is no water source or there are restrictions on the use of water. It is something to be done.

In light of the fact that welding burn-off cleaning operations after past stainless steel welding depend on nitrofluoric acid, which is a very dangerous poisonous substance, as a result of research, the applicant has electrolyzed safe and harmless neutral salts. Developed an electrolytic burn-off method that uses a liquid and obtained a patent No. 1544367 under the name of “descaling method of alloy steel” to suppress the use of the conventional dangerous poisonous nitrile hydrofluoric acid, making it safer We have developed an electrolyzer that enables harmless burn-out.
The gist of the present invention is a direct current electrolysis method in which glycerol is mixed with a neutral salt solution of phosphoric acid, sulfuric acid, and hydrofluoric acid to form an electrolytic solution, and the treated stainless steel is used as an anode.
According to this method, the above-mentioned burn-out operation can be carried out very effectively, but there is a defect that hexavalent chromium which is highly toxic during electrolysis has been dissolved. The company has developed an epoch-making electrolyte that does not elute hexavalent chromium even when electrolytic treatment is performed with a power supply.
In addition, we developed a groundbreaking power supply for electrolytic treatment that does not elute hexavalent chromium even when using a commercially available neutral salt electrolyte with a risk of elution of hexavalent chromium. Patent No. 1908719 is obtained under the name of “scale removal method”.
The gist of the present invention is characterized in that an inorganic neutral salt solution is used as an electrolytic solution, and electrolytic treatment is performed with an AC / DC current obtained by superimposing an alternating current with a direct current with an amplitude equal to or slightly larger than a direct current voltage. Therefore, the harmful hexavalent chromium eluted at the time of electrolysis is immediately reduced to trivalent chromium and has an excellent effect of detoxification.
The present applicant has improved other methods of electrolytic polishing of stainless steel, developed a radioactive decontamination treatment method using an electrolysis method for discarded nuclear power equipment, and a passive film formation treatment that imparts a rust prevention effect to stainless steel. Stainless steel, such as the development of methods for measuring the strength of the coating, and the development of chemicals that can effectively and safely remove the so-called rust and dirt generated on the surface of stainless steel due to air pollution, salt damage, iron powder, etc. New research has been conducted over the entire surface treatment of steel, and great results have been achieved.

  The manual electrolysis apparatus in the present invention is an apparatus that dissolves and removes the burnt of stainless steel using electrolysis, and the basic component of the apparatus is a direct current or an alternating current. Or an AC / DC mixed current power supply, an electrolytic solution composed of an acid, organic or inorganic salt solution, a counter electrode for electrolysis, for example, a stainless steel piece, and the counter electrode It consists of a covering material made of a woven fabric or a non-woven fabric for preventing a short circuit and retaining the electrolytic solution.

An example of a welding burn-off embodiment by this manual electrolysis apparatus is as follows. First, the DC power supply is connected to one end of a stainless steel plate of a material to be treated on which a welding line by electric welding using argon gas as a shielding gas is applied. After connecting the anode and connecting the cathode to one end of the counter electrode on which the covering material is mounted, the counter electrode is welded to the treatment agent in a state where the electrolyte is sufficiently impregnated in the counter electrode covering material. When the electrode is brought into contact with the electrode and energized, an electrolytic action occurs between the agent to be treated and the counter electrode, and an nascent acid is generated on the material to be treated, which dissolves and removes the weld burn of the welding wire of the material to be treated. be able to.
Here, the term “manual type” refers to performing a burn-out operation by electrolysis while picking up and moving the counter electrode along the surface of the weld line when taking the welding burn of the workpiece.
Japanese Patent No. 1543867 Japanese Patent No. 1908719 Patent No. 1905254 Patent No. 1925460 Japanese Patent No. 2649625 Japanese Patent No. 3484525 JP2003-268580 Japanese Patent Application No. 2003-413926

As a problem to be solved, when the burn-out treatment of the welding is performed by the manual electrolysis apparatus described above, the waste liquid contaminated with the electrolytic solution after electrolysis around the weld line is treated on the stainless steel material to be treated. However, it is desirable to remove it completely by washing with water. However, it is difficult to use water at the welding site, and there is no water service at the outdoor site. In most cases, it was not possible to wash with water and simply wipe it off with a cloth or paper. In some cases, there are serious drawbacks that cause corrosion such as rusting.
Regardless of the electrolysis method, the waste liquid remains in the same manner as above on the surface to which the stainless steel rust and dirt are removed using a chemical cleaning agent. It is desirable to remove it completely by washing with water, but it is difficult to use water at the treatment site, and there is no stool at the outdoor site. In most cases, it was only necessary to wipe it off. However, in such a treatment, the waste liquid was not completely removed on the surface to be treated, and it left behind to create stains on the product. There were serious shortcomings that caused the.
In view of such drawbacks, the present invention completely removes the waste liquid after electrolysis remaining on the surface to be treated and the waste liquid from the cleaning agent without using a water washing treatment to clean the treated surface. To provide a new treatment method.

Using an acid or organic or inorganic salt solution as the electrolyte, remove the electrolyte waste remaining on the burned surface after dissolving and removing the weld burn on the stainless steel surface using a manual electrolyzer. In doing so, the treatment surface is directly sprayed with caustic earth powder to adsorb the waste liquid, or the cloth or paper to which the caustic earth powder is previously attached is slightly moistened with water, The removal of the residual waste liquid on the stainless steel treated surface after the electrolytic scavenging process, wherein the waste liquid is brought into contact with the surface and wiped and adsorbed, and the residual waste liquid on the treated surface is removed and cleaned without rinsing with water. It is a cleaning method. When an acid electrolyte is used as described above, acid remains in the waste solution. To neutralize the acid, a caustic alkali and sodium carbonate neutralizer are mixed with the caustic earth beforehand. I will do it.
In addition, an aqueous solution of organic or inorganic salts or an aqueous solution of organic or inorganic acids such as phosphoric acid, citric acid or sulfuric acid is used as a cleaning agent to clean and remove rust and dirt generated on the stainless steel surface. When removing the remaining waste liquid of the cleaning agent, is it possible to spray the caustic earth powder directly on the treated surface to adsorb the waste liquid? Or, the cloth or paper previously adsorbed with caustic soot powder is wetted with water slightly to make contact with the treated surface to wipe away the waste liquid and remove the residual waste liquid on the treated surface without washing. This is a method for removing and purifying residual waste liquid on a stainless steel treated surface that eliminates the need for water washing treatment, which is characterized by cleaning. When an acid cleaning agent is used as described above, acid remains in the waste liquid. To neutralize the acid, a caustic and sodium carbonate neutralizing agent is previously mixed with the caustic soil. I will do it.

  When the above-described manual electrolysis apparatus is used to remove the welding burn of the stainless steel material to be treated, the surface of the material to be treated contains a waste liquid that is contaminated with the electrolytic solution after the electrolysis. When the rust and dirt removal treatment of the stainless steel material to be treated with the agent is performed, the waste liquid after treatment remains on the surface of the material to be treated, and in removing these waste liquids, Conventionally, the removal method using water washing was considered the best method, but the water washing treatment is often impossible depending on the circumstances of the work site. Therefore, the waste liquid still remains on the treated surface, and there were various serious disadvantages that caused the occurrence of post-spots and rust, but according to the present invention, even if it does not depend on the water washing treatment, Such residual waste liquid is completely removed and cleaned. One in which was able to achieve. Therefore, according to the present invention, the welding burn-off treatment of stainless steel using a manual electrolysis apparatus and the post-treatment associated with the rust and dirt removal treatment of stainless steel with a cleaning agent are applied regardless of whether in the factory or outside. Regardless of the location of the water, regardless of the availability of water use, it can be carried out at the site of treatment construction, and the effect of improving the work efficiency can be fully expected.

An electrolytic solution containing 10% sodium tartrate as an aqueous solution is used for 10% sodium sulfate, a 20V DC power supply is used as an electrolysis power supply, and a stainless steel piece of SUS304 is coated as the counter electrode. By using a manual electrolysis apparatus according to the present invention coated with an aramid fiber cloth as a material, an electric welding line using argon gas as a shielding gas is provided on a flat plate surface of a stainless steel material of SUS304 as a material to be processed, and welding burn is performed. After fabrication, the anode of the power supply is connected to one end of the material to be treated, and the cathode is connected to the counter electrode, and the enveloping solution is sufficiently contained in the counter electrode covering material and energized. When this counter electrode is slid along the weld line of the material to be treated, an electrolysis action occurs between the weld line and the counter electrode, and an nascent acid is generated on the anode side to dissolve and remove the welding burn. Electrolyte waste liquid remains around the weld line after scoring.
Regardless of the electrolysis method, when the stainless steel rust and dirt are cleaned and removed using, for example, a detergent mainly composed of sodium thioglycolate, the dirty waste liquid remains on the surface of the material to be treated in the same manner as described above. is doing. In the present invention, after spreading the caustic earth powder on the waste liquid of the material to be treated and adsorbing the waste liquid, the process is a process of wiping with cloth or paper, or an appropriate amount of caustic earth powder is previously applied to the cloth or paper. Adhere to it, moisten it slightly with water at the time of use, and abut against the waste liquid to adsorb and wipe it off. By carrying out such treatment steps, the residual waste liquid of the material to be treated was completely adsorbed, and the treatment effect was able to obtain a cleanliness equivalent to that of the water washing treatment.
Here, the main constituent material, caustic earth, was adopted as an adsorbent treatment material. The caustic earth, which is a soft rock made of diatom shells, has a porous structure as its characteristic, and has a light polishing power. This is because of the excellent adsorption performance of liquids. As a result of testing on many silicic acid-based materials or any other materials having abrasiveness and adsorption ability, no alternative was found. This is because it has been confirmed that it is the only material for the removal and cleaning of residual waste liquid. In order to obtain a high degree of cleanliness, it is essential to select high-quality caustic soil.

In the above embodiment, an example in which a neutral electrolytic solution is used has been shown. However, in this embodiment, an example in which welding is burned out with an acidic electrolytic solution containing phosphoric acid as a main component is shown. The manual electrolyzer, the material to be treated, and the electrolytic burn-off treatment were performed as before. In this case, the liquid property of the electrolyte solution remaining on the surface to be treated is naturally acidic, and if such waste solution remains even in a trace amount, the material to be treated may cause a serious defect depending on the use as a product. Therefore, a complete neutralization process is required.
For this reason, caustic alkali and sodium carbonate-based neutralizing agent are mixed in the caustic earth powder in this example so that the neutralization treatment of the acid is performed simultaneously with the adsorption treatment with the caustic soda powder of the waste liquid. I am considering. As a result of the treatment in this example, in addition to the effect of removing the burn-in of the surface to be treated, there was no residue of waste liquid and the surface to be treated was beautiful without any loss of the original gloss of stainless steel. Further, when the pH of the treated surface was measured, it was confirmed to be pH 7 and neutral.

An example of the cleaning method for removing the cleaning agent and the reaction product remaining on the surface of the treated material after rust removal, that is, the waste liquid, when the rust / dirt cleaning agent is used is shown below.
Rust stain removal cleaning agent mainly composed of an aqueous solution containing 10-20% thioglycolic acid neutral salt is received as a material to be treated and sprayed on the surface of stainless steel of SUS430 material where rust is generated or brushed. Then, the rust and dirt on the surface are brilliantly removed by the reducing action of the chemical, but reaction products and waste liquid of rust and cleaning agent remain on the surface to be treated after such rust removal.
In the rust removal treatment, if the eluted iron ions are not completely removed, a rust phenomenon will eventually occur and rust will be generated again. Therefore, it is necessary to completely remove the residual waste liquid of the material to be treated.
Therefore, in the present invention, after removing the waste liquid by adsorbing and removing the waste liquid on the waste liquid of the material to be treated after the rust removal cleaning, the powder was wiped and cleaned.
By carrying out such a treatment process, the residual waste liquid of the material to be treated was completely adsorbed and removed, and the treatment effect was comparable to the water washing treatment, and the same cleanliness could be obtained.
As another treatment mode, an appropriate amount of caustic earth powder is previously attached to cloth or paper, slightly moistened with water at the time of use, and then in contact with the waste liquid to adsorb and wipe it up. The cleaning effect is equivalent to the previous example.

In the above embodiment, an example of using a neutral rust stain removing cleaning agent has been shown. However, in this embodiment, an acid or rust stain removing agent mainly composed of organic or inorganic acids such as phosphoric acid, sulfuric acid or citric acid is used. An example of waste liquid removal treatment on the stainless steel surface when using a cleaning agent is shown.
As the material to be treated, a stainless steel plate made of SUS304 with rust was generated. The rust removal method using this cleaning agent was the same as in the above example. At this time, the liquidity of the waste liquid remaining on the surface of the material to be treated is of course acidic, and if such waste liquid remains even in a very small amount, the material to be treated must be used as a product, for example, in semiconductor manufacturing equipment. Because it is prohibited, a complete neutralization treatment is required.
For this reason, in this example, caustic and sodium carbonate neutralizing agents are mixed with the caustic soda powder, and consideration is given to the neutralization of the acid at the same time as the adsorption treatment with the caustic soda powder of the waste liquid. ing. As a result of the treatment in this example, in addition to the effect of removing rust stains on the surface to be treated, there was no waste liquid remaining. Further, when the pH of the treated surface was measured, it was confirmed that it was pH 7 and was in a neutral state.

Claims (4)

An aqueous solution of organic or inorganic salts is used as the electrolyte, and the waste solution of the electrolyte remaining on the burned surface after the weld burn on the stainless steel surface is dissolved and removed using a manual electrolysis device is removed. In the state where the waste water is adsorbed by directly spraying the caustic clay powder on the treated surface, or the cloth or paper to which the caustic clay powder is previously attached is slightly moistened with water, Cleaning and removing residual waste liquid on stainless steel treated surfaces that eliminates the need for water washing treatment, wherein the waste liquid contacts and wipes and adsorbs to remove and purify residual waste liquid on the treated surface without depending on water washing Law. Using an aqueous solution of organic or inorganic acids such as phosphoric acid or sulfuric acid, or a mixture thereof as an electrolytic solution, and removing the burnt surface of the stainless steel surface using a manual electrolysis device, the burned surface. In removing the electrolyte waste liquid remaining on the treated surface, the acid waste liquid is neutralized by directly spraying the caustic earth powder with a mixture of caustic and sodium carbonate neutralizer on the treated surface. Or a cloth or paper in which a powder obtained by mixing the caustic alkali and sodium carbonate-based neutralizing agent in advance with caustic earth powder is wetted with water, and is in contact with the treated surface. The neutral waste liquid is neutralized and wiped and absorbed, and the residual waste liquid on the treated surface is removed and cleaned without using water washing. Removal cleaning method When using an aqueous solution of organic or inorganic salts as a cleaning agent, the waste liquid of the cleaning agent remaining on the processing surface after cleaning and removing rust and dirt generated on the stainless steel surface is removed directly against the processing surface. Sprinkle the powder of caustic earth to adsorb the waste liquid, or wipe the adsorbed liquid by contacting the treated surface in a state where the cloth or paper to which the caustic earth powder is previously adhered is slightly moistened with water. A method for removing and cleaning the residual waste liquid on the treated surface of stainless steel, which eliminates the need for a water washing process, wherein the residual waste liquid on the treated surface is removed and cleaned without using water washing. Using an aqueous solution of organic or inorganic acids such as phosphoric acid or sulfuric acid or a mixture of these as a cleaning agent, remove the waste liquid of the cleaning agent remaining on the treated surface after cleaning and removing rust and dirt generated on the stainless steel surface. In this case, the powder treated with a caustic alkali and sodium carbonate neutralizer is directly sprayed on the treated surface to neutralize and adsorb the acidic waste liquid, or in advance the caustic powder. Wipe the cloth or paper with a mixture of the caustic and sodium carbonate neutralizing agent on the surface and slightly wet with water while neutralizing the acidic waste liquid by contacting the treated surface. A method for removing and cleaning residual waste liquid on a treated surface of a stainless steel, which eliminates the need for water washing, wherein the residual waste liquid on the treated surface is removed and cleaned without being washed with water.