High-precision online detection method for hydrogen ion concentration

Abstract

The invention discloses a hydrogen ion concentration high-precision online detection method which is characterized by comprising the following steps: sampling a sample: additionally arranging a circulating bypass pipeline at a main pipeline, and sampling in the bypass pipeline; filtering the sample: filtering the sample; titration detection: dropwise adding NaOH with the concentration of N into the treated sample, recording the consumed capacity V, and adding a certain amount of a color developing agent at the same time; process detection: recording potential and color change conditions in the titration process, and stopping titration when the color or potential of the solution changes suddenly; according to the invention, the potential change condition is matched with the color reaction for recording, the specific reaction process of neutralization titration can be timely and accurately recorded in real time, the recorded potential and color change can be fed back to a control center, and a worker can record and judge in the background and timely adjust the process flow.

Description

Technical Field

[0001] The present invention relates to the technical field of ion detection methods, and in particular to a high-precision online detection method for hydrogen ion concentration. Background Art

[0002] In the process of nickel electrolysis, it is necessary to create conditions that allow hydrogen to be precipitated preferentially on the cathode and nickel to dissolve normally on the anode, thereby enriching the nickel ions in the electrolyte. Therefore, sulfuric acid needs to be added to the electrolyte to maintain the appropriate acidity of the electrolyte and inhibit the precipitation of nickel. At the same time, the acidity must be kept low so as not to affect the purification production.

[0003] The electrolyte for nickel electrolysis is composed of a certain amount of sulfuric acid mixed with copper slag leaching solution, iron alum slag filtrate, anode mud washing solution, electrolytic waste acid and external liquid. Since the acidity of these solutions is different and the difference is large, it is necessary to adjust the appropriate acidity to prepare the acid and liquid. The corresponding result is obtained by detecting the hydrogen ion concentration in the solution, which facilitates timely process control and rectification of the corresponding acidity on the production line to ensure the normal progress of production.

[0004] Most of the existing industrial scenarios use pH glass electrodes for detection. pH glass electrodes are large in size, fragile, inconvenient to store and use, and are contact-type detection, easily contaminated, and have a slow response time. In addition, its test value for low ionic strength systems is unstable, and it is easily affected by electromagnetic and radio frequency interference, making it impossible to quickly and accurately measure it. Compared with traditional pH glass electrodes, photometric pH detection devices have the advantages of requiring less test liquid, being resistant to electromagnetic and radio frequency interference, having a large dynamic range, a short response time, and high measurement accuracy. However, their detection speed still cannot meet the requirements (sub-second) for tracking pH changes during rapid chemical reactions of solutions.

[0005] Therefore, how to quickly detect the acidity of the solution on site and ensure the accuracy of the detection is a key issue that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide a high-precision online detection method for hydrogen ion concentration, which solves the problems of low on-site detection efficiency and low detection accuracy proposed by the above background technology.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A high-precision online detection method for hydrogen ion concentration, Sample sampling: add a circulating bypass pipeline to the main pipeline and take samples from the bypass pipeline; Sample filtration: filtering the sample; Titration detection: NaOH with a concentration of N is added dropwise to the treated sample, and the consumed volume V is recorded, and a certain amount of color developer is added at the same time.

[0008] Process detection: Record the changes in potential and color during the titration process. If there is a sudden change in solution color or potential, the titration is terminated.

[0009] Furthermore, hydrogen ion concentration = V*N*f*0.049*100 / m, V is the amount of NaOH consumed in titrating sulfuric acid; N is the equivalent concentration of the standard NaOH solution; f is the solution coefficient of the standard NaOH solution; m is the mass of the sulfuric acid sample being tested; and 0.049 is the mass of equivalent sulfuric acid per milliliter.

[0010] Furthermore, the pH potential at the titration endpoint was set to 160 mV.

[0011] Furthermore, the developer is methyl orange.

[0012] Furthermore, the solution color is observed through a CCD photosensitive element.

[0013] Furthermore, the solution potential is measured using a pH electrode.

[0014] Beneficial effect: By recording the change of potential in combination with the color reaction, the specific reaction process of the neutralization titration can be recorded timely and accurately, and real-time records are available. At the same time, the recorded potential and color changes can be fed back to the control center, and the staff can record and judge in the background and adjust the process in time. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The present application provides a high-precision online detection method for hydrogen ion concentration, wherein preliminary sample sampling is performed, the sample sampling pipeline is directly connected to the main pipeline, a circulating bypass pipeline is added to the main pipeline, and the bypass pipeline is directly connected back to the inside of the main pipeline after coming out of the main pipeline, so that real-time sampling can be performed during the routine solution discharge process of the main pipeline. When sampling is performed, the bypass pipeline retains the same solution as the main pipeline. When sampling is performed, appropriate samples are directly drained from the bypass pipeline, which can ensure the timeliness of the solution and will not affect the normal transmission work of the main pipeline.

[0016] The collected samples need to be filtered to facilitate subsequent titration.

[0017] The treated samples will be placed in the corresponding detection pool and quantitatively injected through a titrator. The injected samples are NaOH solution and methyl orange. The methyl orange is a color change indicator and is a commonly used indicator in factory laboratories.

[0018] During the reaction process between the NaOH solution and the sample, the color of the solution changes, and methyl orange is used to display the change. However, the color change reaction is fast and cannot be intuitively understood. The solution is monitored in real time by a CCD photosensitive element, and the solution changes are continuously recorded during the titration process. When the reaction change requirements are met, the color will suddenly change and can be recorded.

[0019] At the same time, during the titration process, the pH potential will change. A corresponding pH electrode is placed in the detection cell. The pH electrode will monitor the potential during the titration reaction. When the neutralization reaction occurs, the potential will suddenly change, and the titration reaction will stop.

[0020] The reaction changes were recorded in real time through the changes in solution and potential. The pH electrode was set to stop when the potential reached 160 mV. At the same time, the amount of NaOH consumed was recorded and set as V.

[0021] Hydrogen ion concentration = V*N*f*0.049*100 / m, V is the amount of NaOH consumed in titration; N is the equivalent concentration of standard NaOH solution; f is the solution coefficient of standard NaOH solution; m is the mass of the sample to be tested; 0.049 is the mass of the equivalent sample per milliliter.

[0022] The above textual descriptions illustrate the structures of some specific embodiments of the present invention, which are not exhaustive or limited to the specific forms described above. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-precision online detection method for hydrogen ion concentration, characterized in that: Sample sampling: add a circulating bypass pipeline to the main pipeline and take samples from the bypass pipeline; Sample filtration: filtering the sample; Titration detection: add NaOH with a concentration of N to the treated sample, record the consumed volume V, and add a certain amount of color developer at the same time; Process detection: Record the changes in potential and color during the titration process. If there is a sudden change in solution color or potential, the titration is terminated.

2. A high-precision online detection method for hydrogen ion concentration according to claim 1, characterized in that: Hydrogen ion concentration = V*N*f*0.049*100 / m, V is the amount of NaOH consumed in titrating sulfuric acid; N is the equivalent concentration of standard NaOH solution; f is the solution coefficient of standard NaOH solution; m is the mass of the sulfuric acid sample to be tested; 0.049 is the mass of equivalent sulfuric acid per milliliter.

3. A high-precision online detection method for hydrogen ion concentration according to claim 1, characterized in that: The pH potential at the titration endpoint was set at 160 mV.

4. A high-precision online detection method for hydrogen ion concentration according to claim 1, characterized in that: The developer is methyl orange.

5. A high-precision online detection method for hydrogen ion concentration according to claim 1, characterized in that: The solution color is observed through the CCD photosensitive element.

6. A high-precision online detection method for hydrogen ion concentration according to claim 1, characterized in that: The solution potential was measured using a pH electrode.