Cyanide generation and absorption efficiency monitoring method based on gradient change of two-color indicator

Abstract

The invention provides a cyanide generation and absorption efficiency monitoring method based on double-color indicator gradient change, and belongs to the technical field of cyanide monitoring, the absorption process is visually reflected through the double-color indicator gradient change, the absorption efficiency can be rapidly judged through color change without a complex instrument, the operation is simple and convenient, and the cost is low. And gradient color development and spectral analysis are combined, so that the detection limit can reach a mu g / L level, the trace detection requirement is met, and the absorption condition of the low-concentration cyanide can be accurately monitored. Through real-time change of the color gradient, the concentration distribution and the reaction process of the cyanide in the absorption process can be dynamically reflected, real-time data support is provided for industrial process control and environmental emergency monitoring, expensive detection equipment is not needed, the reagent cost is low, and the method is suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of cyanide monitoring technology, specifically to a method for monitoring cyanide generation absorption efficiency based on gradient changes of a two-color indicator. Background Technology

[0002] Cyanides are widely used in industrial production, such as electroplating, metallurgy, and chemical industries. However, cyanides are extremely toxic and pose a significant threat to the environment and human health. In production processes involving cyanides, accurate monitoring of cyanide generation and absorption efficiency is crucial. This helps to adjust production processes in a timely manner, reduce cyanide leaks and emissions, and ensure production and environmental safety.

[0003] Currently, commonly used methods for cyanide monitoring mainly include electrochemical methods, spectroscopic methods, and chromatographic methods. Electrochemical methods detect cyanide concentration by measuring changes in current or potential at electrodes, but they are easily affected by interference from other ions in the solution, and the electrodes require regular maintenance and calibration, making the operation complex. Spectroscopic methods utilize the absorption characteristics of cyanide at specific wavelengths of light for detection, offering high sensitivity and accuracy, but require expensive equipment and demanding sample pretreatment. While chromatographic methods can accurately separate and detect cyanide, they are time-consuming, costly, and difficult to implement in real-time online monitoring.

[0004] Therefore, there is an urgent need for a method that is simple to operate, low in cost, and capable of real-time monitoring of cyanide generation and absorption efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a method for monitoring the absorption efficiency of cyanide generation based on the gradient change of a two-color indicator, so as to solve the problems of complex operation, high cost and difficulty in real-time monitoring of existing monitoring methods mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] A method for monitoring cyanide generation absorption efficiency based on gradient changes of a two-color indicator includes the following steps:

[0008] S1. Preparation of a two-color indicator:

[0009] Alizarin and curcumin were selected as indicators with different response characteristics to cyanide, and after being prepared into solutions, they were mixed to obtain a two-color indicator solution.

[0010] S2, Preparation of the absorption liquid

[0011] A gradient colorimetric system was formed by adding sodium hydroxide and a two-color indicator solution to obtain the absorption solution.

[0012] S3, Preparation of silicone loading indicator

[0013] A nanoporous silica carrier was added to the absorption liquid to obtain a silica-loaded indicator.

[0014] S4. Construct a monitoring device, including a cyanide generator, an absorption device, and a reaction channel, and install a light source and a photodetector on the outside of the reaction channel;

[0015] Inject the silica gel-loaded indicator into the reaction channel to form a uniform liquid film;

[0016] Cyanide gas is introduced to react with the silica gel-loaded indicator, producing a color gradient change. An absorption efficiency calculation model is established using the synergistic color-changing effect of the silica gel-loaded indicator. The light intensity change is detected by a photodetector. The silica gel-loaded indicator exhibits a gradient color change with the absorption and diffusion of HCN. The range and intensity of the color gradient reflect the absorption efficiency.

[0017] The solution preparation method of the indicator is as follows: Weigh 0.1-0.2g of alizarin, dissolve it in 100mL of ethanol, adjust the pH to 8-10 with sodium hydroxide solution, and stir evenly to obtain an alizarin solution; Weigh 0.05-0.1g of curcumin, dissolve it in 100mL of ethanol, adjust the pH to 6-8 with hydrochloric acid solution, and stir evenly to obtain a curcumin solution.

[0018] Preferably, the solution preparation method of the absorbent is as follows: take 20-25 mL of 0.1 mol / L sodium hydroxide solution, add 5-6 mL of alizarin solution and 2-3 mL of curcumin solution, dilute to 100 mL with deionized water, and shake well for later use.

[0019] Preferably, the reaction channel is provided as a glass tube with an inner diameter of 5-10 mm and a length of 50-100 cm.

[0020] Preferably, the pore size of the nanoporous silica carrier is 20-50 nm, and the specific surface area is >700 m². 2 / g, with a colorimetric response time of 20-30 seconds.

[0021] Preferably, the formula for the absorption efficiency calculation model is as follows:

[0022]

[0023] The absorption efficiency formula is: Absorption efficiency = (Cyanide concentration at the inlet of the reaction channel - Cyanide concentration at the outlet of the reaction channel) / Cyanide concentration at the inlet of the reaction channel × 100%.

[0024] Preferably, the light source is a light-emitting diode with a wavelength of 400-700nm, and the photodetector is a photodiode that issues an alarm signal when it detects a change in light intensity exceeding a set threshold.

[0025] By adopting the above structure and method, the present invention has the following advantages:

[0026] This invention visually reflects the absorption process through the gradient change of a two-color indicator. Absorption efficiency can be quickly determined by color changes without the need for complex instruments. It is simple to operate, and combined with gradient color development and spectral analysis, the detection limit can reach the μg / L level, meeting the needs of trace detection and accurately monitoring the absorption of low concentrations of cyanide. The real-time changes in the color gradient dynamically reflect the concentration distribution and reaction progress of cyanide during absorption, providing real-time data support for industrial process control and environmental emergency monitoring. It requires no expensive detection equipment, uses low-cost reagents, and is suitable for large-scale application.

[0027] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the gradient color rendering of the present invention. Detailed Implementation

[0030] Specific embodiments of the invention will now be described in detail. Although the invention is described in conjunction with these specific embodiments, it should be understood that the invention is not intended to be limited to these specific embodiments. Rather, these embodiments are intended to cover alternative, modified, or equivalent embodiments that may be included within the spirit and scope of the invention as defined by the claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. The invention may be practiced without some or all of these specific details. In other instances, well-known processes have not been described in detail so as not to unnecessarily obscure the invention.

[0031] When used in conjunction with the terms "comprising," "method comprising," or similar language in this specification and appended claims, the singular forms "a," "some," and "the" include plural references unless the context clearly indicates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] The present invention will now be described in further detail with reference to the full text.

[0033] Combined with appendix Figure 1 A method for monitoring cyanide generation absorption efficiency based on gradient changes of a two-color indicator includes the following steps:

[0034] S1. Preparation of a two-color indicator:

[0035] Alizarin and curcumin were selected as indicators with different response characteristics to cyanide, and after being prepared into solutions, they were mixed to obtain a two-color indicator solution.

[0036] S2. Preparation of the absorption solution:

[0037] A gradient colorimetric system was formed by adding sodium hydroxide and a two-color indicator solution to obtain the absorption solution.

[0038] S3. Preparation of silicone loading indicator:

[0039] A nanoporous silica carrier was added to the absorption liquid to obtain a silica-loaded indicator.

[0040] S4. Set up monitoring equipment:

[0041] It includes a cyanide generator, an absorption device, and a reaction channel, with a light source and a photodetector installed outside the reaction channel;

[0042] Inject the silica gel-loaded indicator into the reaction channel to form a uniform liquid film;

[0043] Cyanide gas is introduced to react with the silica gel-loaded indicator, producing a color gradient change. An absorption efficiency calculation model is established using the synergistic color-changing effect of the silica gel-loaded indicator. The light intensity change is detected by a photodetector. The silica gel-loaded indicator exhibits a gradient color change with the absorption and diffusion of HCN. The range and intensity of the color gradient reflect the absorption efficiency.

[0044] The solution preparation method of the indicator is as follows: Weigh 0.1-0.2g of alizarin, dissolve it in 100mL of ethanol, adjust the pH to 8-10 with sodium hydroxide solution, and stir evenly to obtain an alizarin solution; Weigh 0.05-0.1g of curcumin, dissolve it in 100mL of ethanol, adjust the pH to 6-8 with hydrochloric acid solution, and stir evenly to obtain a curcumin solution;

[0045] The solution preparation method of the absorbent is as follows: Take 20-25 mL of 0.1 mol / L sodium hydroxide solution, add 5-6 mL of alizarin solution and 2-3 mL of curcumin solution, and dilute to 100 mL with deionized water. Shake well and set aside.

[0046] The reaction channel is constructed using a glass tube with an inner diameter of 5-10 mm and a length of 50-100 cm. This ensures a balance between the gas-liquid contact area and the reaction time, forming a stable concentration gradient field. Specifically, a cyanide generator and an absorption device are constructed, with a transparent glass tube connecting them as the reaction channel. The reaction channel has an inner diameter of 5-10 mm and a length of 50-100 cm. Sampling points are set at the inlet and outlet of the reaction channel to collect gas samples before and after the reaction. Multiple light sources and photodetectors are evenly arranged axially on the outside of the reaction channel. The light emitted by the light sources passes perpendicularly through the reaction channel, and the photodetectors detect the intensity of the light transmitted through the reaction channel.

[0047] Based on the degree of color change at the inlet and outlet of the reaction channel, a correlation between color change and cyanide concentration is established, and the cyanide concentration at the inlet and outlet is calculated. Then, the cyanide absorption efficiency is calculated using the following formula:

[0048] Absorption efficiency (%) = (cyanide concentration at the inlet - cyanide concentration at the outlet) / cyanide concentration at the inlet × 100%.

[0049] Specifically, multiple detection points are set along the axial direction (e.g., every 10 cm). A combination of LED light source (400-700nm full spectrum coverage) and photodiodes is used to capture real-time changes in light intensity at different locations, constructing a three-dimensional spatial-color-concentration mapping model. This overcomes the limitations of traditional offline sampling and single-point detection methods, enabling dynamic monitoring of the entire cyanide generation and absorption process with a response time down to the second level, meeting the real-time control needs of industrial sites.

[0050] The nanoporous silica carrier has a pore size of 20-50 nm and a specific surface area >700 m². 2 / g, with a colorimetric response time of 20-30 seconds.

[0051] The formula for the absorption efficiency calculation model is as follows:

[0052]

[0053] A 642 A represents the absorbance of the silica-loaded indicator at a wavelength of 642 nm. 525 The absorbance of the silica-loaded indicator at a wavelength of 642 nm is given.

[0054] Blank value: The ratio of absorbance of the indicator system that has not reacted with cyanide, used to eliminate background interference.

[0055] Calculate the absorbance difference or superposition value to establish a quantitative relationship between color change and cyanide concentration, and then evaluate the absorption efficiency in real time.

[0056] Visual monitoring: The gradient change of the two-color indicator intuitively reflects the absorption process. Absorption efficiency can be quickly determined by color change without the need for complicated instruments, and the operation is simple.

[0057] High sensitivity: Combining gradient colorimetry and spectral analysis, the detection limit can reach the μg / L level, meeting the needs of trace detection and accurately monitoring the absorption of low concentrations of cyanide.

[0058] Real-time dynamic assessment: By observing the real-time changes in the color gradient, the concentration distribution and reaction process of cyanide during absorption can be dynamically reflected, providing real-time data support for industrial process control and environmental emergency monitoring.

[0059] Low cost: No expensive testing equipment is required, and reagents are inexpensive, making it suitable for large-scale application.

[0060] The absorption efficiency formula is: Absorption efficiency = (Cyanide concentration at the inlet of the reaction channel - Cyanide concentration at the outlet of the reaction channel) / Cyanide concentration at the inlet of the reaction channel × 100%.

[0061] The light source is a light-emitting diode (LED) with a wavelength of 400-700nm, and the photodetector is a photodiode. When the detected light intensity change exceeds a set threshold, an alarm signal is issued. LEDs offer advantages such as low power consumption, long lifespan, and good stability, providing a stable light source. Photodiodes have high sensitivity and response speed, enabling real-time detection of light intensity changes. When the light intensity change detected by the photodetector exceeds the set threshold, an alarm signal is issued to alert operators. By setting an alarm threshold, abnormalities in the cyanide generation and absorption process can be detected promptly, ensuring production safety.

[0062] Specifically, a dynamic threshold algorithm is embedded in the photodetector signal processing module. When the rate of change in light intensity exceeds a preset safety threshold (e.g., 10% / min), an audible and visual alarm is automatically triggered. This enables real-time early warning of abnormal operating conditions such as sudden leaks and absorption device failures, detecting risks 10-30 minutes earlier than manual inspections. This provides proactive protection for safe production and aligns with the intelligent development trend of the Industrial Internet of Things (IIoT).

[0063] Specifically, light-emitting diodes (LEDs) and photodiodes are used as light sources and detectors to replace the high-power light sources and complex spectroscopic systems of traditional spectrometers, reducing costs by more than 70%. They also have low power consumption (power consumption of a single light source is <1W) and long lifespan (>50,000 hours), eliminating the need for regular calibration. A monitoring system of "low-cost hardware + intelligent algorithms" has been constructed, solving the industry pain points of "expensive instruments and difficult maintenance" in traditional methods, making it particularly suitable for promotion and application by small and medium-sized enterprises.

[0064] The color gradient distribution of the absorbent solution inside the absorption bottle. On the left, near the HCN inlet, is a high-concentration zone; alizarin is blue, curcumin is orange, and the mixture appears bluish-purple. The middle zone is a gradient transition area, where alizarin and curcumin gradually transition colors, forming a blue-green-yellow gradient band. On the right, further from the inlet, is a low-concentration zone; alizarin is purple, curcumin is yellow, and the mixture appears yellowish-green. The narrower the color gradient band, the more complete the HCN absorption and the higher the absorption efficiency.

[0065] A bar chart is used to represent the color gradient of the mixed two-color indicator at different cyanide concentrations. The horizontal axis represents the cyanide concentration range, and the vertical axis represents the absorbance or other quantitative indicators corresponding to the color. Each column is filled with the color corresponding to the concentration, and the approximate color and the corresponding cyanide concentration range are marked, showing the color gradient distribution of the absorbent solution. The high-concentration region is near the HCN inlet, where alizarin is blue and curcumin is orange, resulting in a bluish-purple color after mixing. The middle region is the gradient transition zone, where alizarin and curcumin gradually transition colors, forming a blue-green-yellow gradient band. The low-concentration region is further from the inlet, where alizarin is purple and curcumin is yellow, resulting in a yellowish-green color after mixing. The narrower the color gradient band, the more complete the HCN absorption and the higher the absorption efficiency, providing a direct quantitative representation of the relationship between cyanide concentration, absorbance response, and absorption efficiency.

[0066] In practical implementation, this invention can be divided into three regions:

[0067] High concentration area (near the HCN entrance): Alizarin is blue, curcumin is orange, and when mixed, it appears bluish-purple;

[0068] Intermediate gradient zone: Alizarin and curcumin transition colors, forming a blue-green-yellow gradient band;

[0069] Low concentration zone (far from the inlet): Alizarin is purple, curcumin is yellow, and the mixture appears yellowish-green. The narrower the color gradient range, the higher the absorption efficiency.

[0070] The dual-color indicators of this invention (such as alizarin and curcumin) form gradient color bands in alkaline absorption solutions. Alizarin gradually changes from purple to blue in the pH range of 8-10, while curcumin gradually changes from yellow to orange in the pH range of 6-8. The color transition regions of the two directly reflect the pH gradient changes during cyanide absorption.

[0071] After absorption, the absorbent solution was transferred to a cuvette, and the absorbance was measured at wavelengths of 525 nm and 642 nm. The ΔA = Aλ1 + Aλ2 was calculated, and the cyanide concentration and absorption efficiency were obtained by comparing with a standard curve. The ΔA value showed a linear relationship with the cyanide concentration. The mathematical model for the color gradient length (L) and absorption efficiency (η) was: η = 1 - L / L0 × 100%.

[0072] Where L0 is the color gradient length without cyanide. When the cyanide concentration is low, ΔA and η increase exponentially; when the concentration is high, ΔA tends to saturate, and η approaches 100%. The inflection point of the curve corresponds to the optimal absorption conditions (such as NaOH concentration and reaction temperature).

[0073] Example 1:

[0074] A method for monitoring the absorption efficiency of cyanide generation based on gradient changes of a two-color indicator, characterized by comprising the following steps:

[0075] S1. Preparation of a two-color indicator:

[0076] Alizarin and curcumin were selected as indicators with different response characteristics to cyanide. 0.1 g of alizarin was weighed, dissolved in 100 mL of ethanol, and the pH was adjusted to 8 with sodium hydroxide solution. The solution was stirred evenly to obtain an alizarin solution. 0.05 g of curcumin was weighed, dissolved in 100 mL of ethanol, and the pH was adjusted to 6 with hydrochloric acid solution. The solution was stirred evenly to obtain a curcumin solution.

[0077] After preparing solutions separately, they are mixed to obtain a two-color indicator solution;

[0078] S2. Preparation of the absorption solution:

[0079] A gradient colorimetric system was formed by adding sodium hydroxide and a two-color indicator solution. The absorption solution was prepared as follows: 20 mL of 0.1 mol / L sodium hydroxide solution was added, along with 5 mL of alizarin solution and 2 mL of curcumin solution. The solution was then diluted to 100 mL with deionized water and shaken well to obtain the absorption solution.

[0080] S3. Preparation of silicone loading indicator:

[0081] A nanoporous silica support was added to the absorption liquid to obtain a silica-loaded indicator. The nanoporous silica support had a pore size of 20 nm and a specific surface area of ​​850 m². 2 / g;

[0082] S4. Set up monitoring equipment:

[0083] It includes a cyanide generator, an absorption device, and a reaction channel, with a light source and a photodetector installed outside the reaction channel;

[0084] Inject the silica gel-loaded indicator into the reaction channel to form a uniform liquid film;

[0085] Cyanide gas is introduced to react with the silica gel-loaded indicator, producing a color gradient change. An absorption efficiency calculation model is established using the synergistic color-changing effect of the silica gel-loaded indicator. The light intensity change is detected by a photodetector. The silica gel-loaded indicator exhibits a gradient color change with the absorption and diffusion of HCN. The range and intensity of the color gradient reflect the absorption efficiency.

[0086] Based on the changes in light intensity at the entrance and exit, a correlation was established between color change and cyanide concentration, and the cyanide concentration at the entrance was calculated to be 100 mg / m³. 3 The cyanide concentration at the outlet is 20 mg / m³. 3 Therefore, the absorption efficiency is (100-20) / 100×100%=80%.

[0087] Example 2:

[0088] A method for monitoring the absorption efficiency of cyanide generation based on gradient changes of a two-color indicator, characterized by comprising the following steps:

[0089] S1. Preparation of a two-color indicator:

[0090] Alizarin and curcumin were selected as indicators with different response characteristics to cyanide. 0.2 g of alizarin was weighed, dissolved in 100 mL of ethanol, and the pH was adjusted to 10 with sodium hydroxide solution. The solution was stirred evenly to obtain an alizarin solution. 0.1 g of curcumin was weighed, dissolved in 100 mL of ethanol, and the pH was adjusted to 8 with hydrochloric acid solution. The solution was stirred evenly to obtain a curcumin solution.

[0091] After preparing solutions separately, they are mixed to obtain a two-color indicator solution;

[0092] S2. Preparation of the absorption solution:

[0093] A gradient colorimetric system was formed by adding sodium hydroxide and a two-color indicator solution. The absorption solution was prepared as follows: 25 mL of 0.1 mol / L sodium hydroxide solution was added, along with 6 mL of alizarin solution and 3 mL of curcumin solution. The solution was then diluted to 100 mL with deionized water and shaken well to obtain the absorption solution.

[0094] S3. Preparation of silicone loading indicator:

[0095] A nanoporous silica support was added to the absorption liquid to obtain a silica-loaded indicator. The nanoporous silica support had a pore size of 50 nm and a specific surface area of ​​900 m². 2 / g;

[0096] S4. Set up monitoring equipment:

[0097] It includes a cyanide generator, an absorption device, and a reaction channel, with a light source and a photodetector installed outside the reaction channel;

[0098] Inject the silica gel-loaded indicator into the reaction channel to form a uniform liquid film;

[0099] Cyanide gas is introduced to react with the silica gel-loaded indicator, producing a color gradient change. An absorption efficiency calculation model is established using the synergistic color-changing effect of the silica gel-loaded indicator. The light intensity change is detected by a photodetector. The silica gel-loaded indicator exhibits a gradient color change with the absorption and diffusion of HCN. The range and intensity of the color gradient reflect the absorption efficiency.

[0100] The cyanide concentration at the entrance was calculated to be 150 mg / m³ based on the test results. 3 The cyanide concentration at the outlet is 30 mg / m³. 3 The absorption efficiency is (150-30) / 150×100%=80%.

[0101] Comparative example:

[0102] Detection of cyanide gas using the isonicotinic acid-pyrazolone method.

[0103] The results of Example 1, Example 2, and the comparative example are shown in Table 1:

[0104] Table 1

[0105] index Example 1 Example 2 Comparative Example Detection limit 0.01 mg / L 0.02 mg / L 0.004 mg / L Response time 25 seconds 20 seconds 10 minutes Dynamic monitoring capability Real-time gradient color rendering Real-time gradient color rendering Endpoint Single Measurement

[0106] This invention, through a systematic design that integrates innovative principles, optimized equipment, cost control, and safety functions, achieves a response time of less than 30 seconds and a detection limit of 0.01 mg / L. By dynamically reflecting the concentration distribution and reaction process of cyanide during absorption through real-time changes in the color gradient, it provides real-time data support for industrial process control and environmental emergency monitoring. It constructs a "visualized, real-time, and intelligent" cyanide monitoring system, providing a new technical path for efficient and safe operation in industrial sites, and has significant industrial application value and technological foresight.

[0107] The present invention and its embodiments have been described above. This description is not restrictive, and the embodiments shown throughout are only one of the embodiments of the present invention. The actual structure is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for monitoring cyanide generation absorption efficiency based on gradient changes of a two-color indicator, characterized in that, Includes the following steps: S1. Preparation of a two-color indicator: Alizarin and curcumin were selected as indicators with different response characteristics to cyanide, and after being prepared into solutions, they were mixed to obtain a two-color indicator solution. S2. Preparation of the absorption solution: A gradient colorimetric system was formed by adding sodium hydroxide and a two-color indicator solution to obtain the absorption solution. S3. Preparation of silicone loading indicator: A nanoporous silica carrier was added to the absorption liquid to obtain a silica-loaded indicator. S4. Set up monitoring equipment: It includes a cyanide generator, an absorption device, and a reaction channel, with a light source and a photodetector installed outside the reaction channel; Inject the silica gel-loaded indicator into the reaction channel to form a uniform liquid film; Cyanide gas is introduced to react with the silica gel-loaded indicator, producing a color gradient change. An absorption efficiency calculation model is established using the synergistic color-changing effect of the silica gel-loaded indicator. The light intensity change is detected by a photodetector. The silica gel-loaded indicator exhibits a gradient color change with the absorption and diffusion of HCN. The range and intensity of the color gradient reflect the absorption efficiency.

2. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 1, characterized in that: The solution preparation method of the indicator is as follows: Weigh 0.1-0.2g of alizarin, dissolve it in 100mL of ethanol, adjust the pH to 8-10 with sodium hydroxide solution, and stir evenly to obtain an alizarin solution; Weigh 0.05-0.1g of curcumin, dissolve it in 100mL of ethanol, adjust the pH to 6-8 with hydrochloric acid solution, and stir evenly to obtain a curcumin solution.

3. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 2, characterized in that: The solution preparation method of the absorbent is as follows: Take 20-25 mL of 0.1 mol / L sodium hydroxide solution, add 5-6 mL of alizarin solution and 2-3 mL of curcumin solution, and dilute to 100 mL with deionized water. Shake well and set aside.

4. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 1, characterized in that: The reaction channel is constructed using a glass tube with an inner diameter of 5-10 mm and a length of 50-100 cm.

5. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 1, characterized in that: The nanoporous silica carrier has a pore size of 20-50 nm and a specific surface area >700 m². 2 / g, with a colorimetric response time of 20-30 seconds.

6. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 1, characterized in that: The formula for the absorption efficiency calculation model is as follows: The absorption efficiency formula is: Absorption efficiency = (Cyanide concentration at the inlet of the reaction channel - Cyanide concentration at the outlet of the reaction channel) / Cyanide concentration at the inlet of the reaction channel × 100%.

7. The method for monitoring cyanide generation absorption efficiency based on gradient change of a two-color indicator according to claim 1, characterized in that: The light source is a light-emitting diode with a wavelength of 400-700nm, and the photodetector is a photodiode. When the light intensity change exceeds a set threshold, an alarm signal is issued.

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