JPS6074263A - Method of adjusting acidity of impregnating solution of porous substrate - Google Patents

Abstract

PURPOSE:To automatically adjust acidity of impregnating solution by leading the impregnating solution in the intermediate case with ladle and calculating added amount of acidic solution through titlation analysis of concentration of acid after it is absorbed by a sampling bullet and is then injected to an analysis cell. CONSTITUTION:A ladle 4 which can be moved vertically is provided within an intermediate case 1 which supplies impregnating solution to an impregnation case which is used for the impregnation process wherein the electrode substrate of alkali storage battery, etc. is impregnated with the active substance, and it is absorbed by a sampling bullet 5 located at the upper part of sample unloading port 1c. Thereafter, the bullet 5 is moved to the upper part of the analysis cell 6 and the sample is placed within the cell 6. Concentration of said is analyzed by titulation and amount acidic solution added from the result of such titulation and such acidic solution is added to the intermediate case 1 from said acidic solution case 3. Thereby, concentration of acid and can be adjusted accurately and automatically, realizing automatic polarity manufacturing process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting the acidity of an impregnating liquid during the production of porous electrode plates for alkaline storage batteries and the like.

In the manufacturing process of storage battery plates, the process of infiltrating active substances into porous substrates is called the impregnation process.For alkaline storage battery electrodes, porous substrates such as sintered nickel plates are immersed in an aqueous solution of nickel or cadmium salts. Then, chemical, electrical or combustion treatments are repeated several times to precipitate a predetermined amount of nickel hydroxide (positive electrode) or cadmium hydroxide (negative electrode) into the pores of the substrate.

In the impregnation process, an impregnating liquid consisting of an aqueous solution of nickel or cadmium nitrate is supplied from the mother tank to an impregnating liquid intermediate tank (hereinafter simply referred to as intermediate tank) and stored there. The impregnating liquid stored in the intermediate tank is supplied to the impregnating tank in which the porous substrate is set, and after a predetermined period of deep soaking, the impregnating liquid is returned to the intermediate layer again.

Further, in the impregnation process, the acid concentration of the impregnating liquid, which has decreased due to the reaction with the substrate, is generally adjusted after the impregnation operation is completed and the impregnating liquid is returned to the intermediate layer from the impregnation tank.

Conventionally, in the above-mentioned impregnation process, the acid concentration of free acid in the impregnating liquid is detected by manual analysis, and the amount of acid to be added is calculated according to the amount of impregnating liquid in the intermediate tank, and the acid liquid (for example, HNO3) is Because it was weighed in a cylinder and added to the impregnating liquid in the intermediate tank, it took a lot of time to analyze it, which delayed the discovery of concentration defects and the resulting adjustment of the free acid concentration of the chemical substance, resulting in a large amount of defects. There was a risk of generating polar plates. Additionally, in winter, crystals form on the tip of a sampling pipette within a few seconds, causing analysis errors.

The present invention has improved the above-mentioned drawbacks, and the gist thereof is to move the ladle supported in the impregnating liquid in the impregnating liquid intermediate tank up and down multiple times to replace the sampling liquid in the ladle, and to replace the sampling liquid in the ladle. a step of drawing out the sampling liquid from the intermediate tank to the outside and inserting the tip of the sampling puret into the picolette, inhaling the sampling liquid into the picolette multiple times, discharging it, and then inhaling a predetermined amount, and transferring the sampling liquid in the burette to the analysis cell. A step of titratingly analyzing the acidity of the injected sampled solution, a step of calculating the amount of acid solution added from the result of the titration analysis and the amount of impregnating solution in the intermediate tank, and transferring the calculated amount of addition to the acid solution tank and adding it to the intermediate impregnating solution. The acid concentration of the impregnating liquid is adjusted by adding the acid to the bath.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is an intermediate tank in which impregnating liquid is stored, and pipe 1 is used to send the impregnating liquid to the impregnating tank (not shown).
a, a stirrer 1b for stirring the impregnation liquid, and a sample outlet 1c. 2 is nickel nitrate aqueous solution,
3 is an acid solution tank, and 3a is a dispenser for measuring a predetermined amount of acid solution and supplying it to the intermediate tank. 4
is a ladle that scoops up the impregnating liquid in the intermediate tank for analysis, and is suspended in the impregnating liquid from the sample outlet 1c of the intermediate tank via the support rod 4b from the lifting device 4a, and is normally kept in the impregnating liquid. The sample is immersed in water and kept warm to prevent analysis errors due to precipitation of crystals due to drop in liquid temperature during sampling. Further, this ladle is constructed as shown in FIG. 3 in order to avoid scooping up floating matter such as dust accumulated in the intermediate tank due to long-term use when sampling a portion of the impregnating liquid. In FIG. 3, the upper surface of a cup-shaped ladle main body 41 is covered with a lid 42 which has a larger diameter than the main body and has a hanging wall 43 on the outer periphery. A liquid flow port 44 is formed,
Further, in the center of the lid, there is a cylindrical body 45 whose lower end is open close to the bottom surface of the main body, and whose upper end is opened so as to protrude from the upper surface of the lid 43.
is provided. Therefore, by moving the ladle up and down in the impregnating liquid, the impregnating liquid flows in and out from the liquid flow port 44 and the upper end of the cylindrical body 45, and the impregnating liquid inside can be replaced. 5 is a sampling buret for sampling a certain amount of impregnation liquid from the ladle and injecting it into the analysis cell; the tip of the buret is attached to a vertical movement device 5a so as to be able to descend into the ladle and the analysis cell; is a lateral movement device 5 consisting of a hydraulic cylinder or the like so as to be able to move between the ladle 4 and the analysis cell 6.
It is attached to b. As shown in FIG. 2, the analysis cell 6 is equipped with a glass container 61 equipped with a pipe 62 for discharging waste liquid into the bottom, a stirrer 63, and a PH meter 64, and the pipe 62 is connected to an on-off valve 65. and discharge pump 6
6 to a waste liquid tank (not shown).

A purified water tank 7 is used to dilute the sample liquid in the analysis cell and to wash the analysis cell, and is supplied to the analysis cell 6 via a pump 7a.

Reference numeral 8 denotes a titration burette, which titrates, for example, a 0.1N NaCO solution into the sample liquid in the analysis cell, and measures the amount until the sample liquid reaches a predetermined value (for example, PH4) to detect acidity. 9 according to a preset program,
This is a control device that sends operation commands to each of the above-mentioned devices in order to sequentially execute the steps described below.

In the above-mentioned apparatus, when the control device 9 receives a command signal from the impregnating tank, first, in order to adjust the amount of impregnating liquid in the intermediate tank 1, a liquid level detector (not shown) disposed in the intermediate tank 1 is activated. is operated, and after replenishing the mother liquor from the mother tank 2 so that the liquid volume becomes a predetermined amount, the stirrer 1b is rotated to stir the impregnating liquid in the intermediate tank for a certain period of time to make the liquid composition uniform.

At the start of acid concentration detection of the impregnating liquid, the sampling buret 5 is stopped on the analysis cell 6, and the analysis cell contains washing water. Therefore, first, the on-off valve 65
is opened and the discharge pump 66 is activated to discharge the washing water inside the cell. Next, water is fed into the analysis cell 6 from the purified water tank 7, the stirrer 63 is turned, and the inside of the analysis cell 6 and the sampling burette 5 are washed (the piston of the burette is operated to suck in and discharge water), and the opening/closing operation is performed. The valve 65 is activated and the discharge pump 66 is operated to discharge the wash water inside the cell. Next, a predetermined amount (for example, 100 cc) of purified water is injected from the purified water tank 7 into the analysis cell as dilution water, and the stirrer 63 is rotated. On the other hand, in the intermediate tank 1, the ladle 4 repeatedly moves up and down a preset number of times of refreshing, and after replacing the impregnating liquid in the ladle, the impregnating liquid is pumped up from the intermediate tank and drawn out. At this time, the sampling buret 5 moves from the position of the analysis cell 6 to the upper part of the ladle 4, and the tip of the buret descends into the cylindrical body 45 of the ladle. In this state, the impregnating liquid in the ladle is sucked into and discharged into the burette 5 several times to make the burette the same acidity as the impregnating liquid and to prevent crystals from precipitating, and to remove any trace of water that remained on the sample when cleaning the burette. Avoid affecting the acid concentration of the liquid. After the suction and discharge operations are completed, a predetermined amount of sample liquid is suctioned, the buret is pulled up and moved onto the analysis cell 6, and the ladle 4 is lowered back into the impregnation liquid in the intermediate tank. The tip of the buret that has been moved to the analysis cell 4 descends into the analysis cell, injects the sampling liquid into the analysis cell, and then rises. The injected sampling liquid is diluted with dilution water in the analysis cell, and titrated by dropping a reagent (e.g. 0.1N NaCO3) from the titration buret 8 while stirring with a stirrer 63 to reach the set pH. When the titration reaches this value, this is detected by the PH meter 64 and the titration operation ends. Here, the on-off valve 65 and the discharge pump 66 are operated to discharge the liquid in the analysis cell to the waste liquid tank.

The acid concentration is calculated from the titration of the reagent measured in this way, the acid addition amount is calculated from the acid concentration setting value of the impregnating liquid and the liquid volume in the intermediate tank, and the dispenser 3a is activated to add the acid. Acid liquid is added from liquid tank 3 into the intermediate tank. Then, after stirring the impregnating liquid by operating the stirring pump 1b of the intermediate tank a again,
Confirmatory analysis is performed by repeating the same process as above.

As described above, the method of the present invention is a method for accurately and automatically adjusting the acid concentration of the impregnating liquid, which is essential for manufacturing porous electrode plates such as alkaline storage batteries, and enables automation of the electrode plate manufacturing process. The effect is extremely large.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be applied to all types of battery electrode plates, as long as a porous substrate is filled with a liquid active substance in the manufacture of the electrode plate. .

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of an apparatus for explaining the method of the present invention, and FIG. 2 is a block diagram showing an acid concentration detection mechanism centered on an analytical cell used in the method of the present invention.
FIG. 3 is a sectional view showing an example of the structure of a ladle used in the present invention. 1... Impregnation liquid intermediate tank 2... Mother tank 3.
... Acid liquid tank 4 ... Laidle 5 ...
...Sampling bullet 6 ...Analysis cell agent Patent attorney Minoru Suzuki

Claims (1)

[Scope of Claims] 1) A step of moving the ladle supported in the impregnating liquid in the impregnating liquid intermediate tank up and down multiple times to replace the sampling liquid in the ladle; A process of pulling out the sampling liquid from the liquid and inserting the tip of the sampling puret, inhaling the sampling liquid into the puret multiple times, expelling it, and then inhaling a predetermined amount; Injecting the sampling liquid in the burette into the analysis cell and removing the acid of the sampling liquid. A step of titration analysis of the concentration, a step of calculating the amount of acid solution added from the result of the titration analysis and the amount of impregnated liquid in the intermediate tank, a step of adding a certain amount of acid solution to the amount of the acid solution added to the acid solution tank. A method for adjusting the acidity of an impregnating solution for a porous substrate, the method comprising: adding the acid to an intermediate tank; 2) The ladle has a cup-shaped main body, a lid that covers the top surface of the main body and has an annular wall that hangs down on the outer periphery with a gap from the outer peripheral wall of the main body, and a lid that penetrates the center of the lid and has a lower end inside the main body. Claim 1: The cylindrical body has a cylindrical body that opens close to the bottom surface of the body and has an upper end that projects upwardly from the upper surface of the lid, and a liquid flow opening is provided at the joint between the upper end of the main body and the lower surface of the lid. The method for adjusting the acidity of an impregnating solution for a porous substrate as described above.