Automatic nitric acid and sulfuric acid preparation method

Abstract

The invention discloses an automatic nitric acid and sulfuric acid preparation method. The method comprises the following steps: mounting specific gravity probes, conductivity probes and near-infrared transmission-type optical fiber probes in a waste acid tank with a stirring function and an acid preparation tank with a stirring function; the components of nitric acid, sulfuric acid and water in the waste acid tank and the acid preparation tank are obtained through data collected by the near-infrared transmission type optical fiber probe or the specific gravity probe and the conductivity probe, so that the waste acid, nitric acid and sulfuric acid are added into the acid preparation tank according to a proper proportion, and the preparation requirement is met. According to the invention, the problems of high working intensity and poor safety caused by manual calculation and charging in the existing acid preparation are solved.

Description

Technical Field

[0001] This invention belongs to the field of chemical raw material technology, specifically relating to an automated method for preparing nitric acid and sulfuric acid. Background Technology

[0002] Nitrocellulose is obtained by esterification of refined cotton with a mixed nitro-sulfur acid in a certain proportion. The acid discharged from the acidic nitrocellulose after esterification is waste acid, which can be reused to prepare the mixed nitro-sulfur acid. Because the esterification reaction consumes nitric acid and produces water, the nitric acid content in the waste acid is lower than that in the mixed acid, while the moisture content is higher. The acid preparation process is as follows: Figure 1 As shown.

[0003] Currently, acid preparation relies on experience. A certain amount of waste acid is collected first, the required amounts of nitric acid and sulfuric acid are estimated, the nitric acid and sulfuric acid valves are opened, the mixture is added, stirred thoroughly, and then sampled for analysis. If the sample passes the test, it is used for esterification; otherwise, further preparation is needed. The problem with this method is that acid preparation relies on manual calculation and feeding, lacks automation, is labor-intensive, and poses certain risks. Therefore, designing an automated acid preparation method is essential. Summary of the Invention

[0004] This invention provides an automated method for preparing nitric acid and sulfuric acid, which solves the problems of high labor intensity and poor safety associated with the existing method of manually calculating and adding materials for acid preparation.

[0005] To achieve the above objectives, the technical solution adopted in this invention is an automated method for preparing nitric acid and sulfuric acid, comprising: installing a specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe in both a waste acid tank with stirring and a mixing acid tank with stirring; obtaining the composition of nitric acid, sulfuric acid, and water in the waste acid tank and the mixing acid tank by data collected by the near-infrared transmission fiber optic probe or the specific gravity probe and conductivity probe, thereby ensuring that the waste acid, nitric acid, and sulfuric acid are added to the mixing acid tank in a suitable ratio to achieve the required configuration.

[0006] As a preferred technical solution of the present invention, the automated method for preparing nitric acid and sulfuric acid is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid through near-infrared spectroscopy and mixed acid chemistry. Make data on the conductivity-specific gravity of the waste acid and the chemical method. Then establish models for nitric acid, water and sulfuric acid, i.e., near-infrared spectroscopy-chemical method model. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of mixed acid components, and establish regression formulas for nitric acid, moisture, and sulfuric acid by comparing the conductivity-specific gravity data with the chemical method data. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0007] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0008] As a preferred technical solution of the present invention, the top of the waste acid tank is provided with a waste acid inlet and three probe interfaces, one or more stirrers, and the bottom is provided with a waste acid outlet. A specific gravity probe, a conductivity probe and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces.

[0009] As a preferred technical solution of the present invention, the top of the acid mixing tank is provided with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, three probe interfaces, and one or more stirrers. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet. The bottom of the acid mixing tank is provided with a substandard acid outlet and a qualified acid outlet.

[0010] As a preferred embodiment of the present invention, the outlet of the substandard acid is connected to the inlet of the waste acid tank.

[0011] As a preferred embodiment of the present invention, a nitric acid valve is provided in the nitric acid inlet.

[0012] As a preferred embodiment of the present invention, a sulfuric acid valve is provided in the sulfuric acid inlet.

[0013] As a preferred embodiment of the present invention, each of the nitric acid tanks is equipped with a level gauge, and the level gauge is interlocked with the nitric acid valve.

[0014] As a preferred embodiment of the present invention, each of the sulfuric acid tanks is equipped with a level gauge, and the level gauge is interlocked with the sulfuric acid valve.

[0015] The beneficial effects of this invention are: the automated nitric acid and sulfuric acid preparation method of this invention uses two technologies, conductivity-specific gravity method and near-infrared spectroscopy, which can determine the more accurate amount of nitric acid and sulfuric acid to be added, avoiding the linear influence of a single method on the results. Attached Figure Description

[0016] Figure 1 This refers to the existing acid preparation process.

[0017] Figure 2 This is a schematic diagram of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0019] Example 1 like Figure 2 As shown, an automated method for preparing nitric acid and sulfuric acid according to the present invention includes: installing a specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe in both a waste acid tank with stirring and a mixing acid tank with stirring; obtaining the composition of nitric acid, sulfuric acid, and water in the waste acid tank and the mixing acid tank by data collected by the near-infrared transmission fiber optic probe or the specific gravity probe and conductivity probe, thereby ensuring that the waste acid, nitric acid, and sulfuric acid are added to the mixing acid tank in a suitable ratio to achieve the required configuration.

[0020] An automated method for preparing nitric acid and sulfuric acid according to the present invention is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0021] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0022] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0023] Example 2 like Figure 2 As shown in Example 1, Example 2 is an automated method for preparing nitric acid and sulfuric acid according to the present invention, which is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0024] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0025] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0026] Unlike Embodiment 1, in Embodiment 2 of the present invention: the top of the waste acid tank is provided with a waste acid inlet, three probe interfaces, and one or more stirrers, and the bottom is provided with a waste acid outlet. The specific gravity probe, conductivity probe, and near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces, which makes the installation more convenient.

[0027] Example 3 like Figure 2 As shown in Example 1, Example 2 is an automated method for preparing nitric acid and sulfuric acid according to the present invention, which is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0028] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0029] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0030] Unlike Embodiment 1, in Embodiment 3 of the present invention: the top of the waste acid tank is provided with a waste acid inlet, three probe interfaces, and one or more stirrers, and the bottom is provided with a waste acid outlet. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces; the top of the acid mixing tank is provided with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, and three probe interfaces. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet; the bottom of the acid mixing tank is provided with a substandard acid outlet and a qualified acid outlet; the installation is relatively convenient.

[0031] Example 4 like Figure 2 As shown in Example 1, Example 4, an automated method for preparing nitric acid and sulfuric acid according to the present invention, is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0032] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0033] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0034] Unlike Embodiment 1, in Embodiment 4 of the present invention: the top of the waste acid tank is provided with a waste acid inlet, three probe interfaces, and one or more stirrers, and the bottom is provided with a waste acid outlet. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces; the top of the acid mixing tank is provided with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, three probe interfaces, and one or more stirrers. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet; the bottom of the acid mixing tank is provided with a substandard acid outlet and a qualified acid outlet. The substandard acid outlet is connected to the waste acid inlet in the waste acid tank, and the qualified acid outlet is connected to the production line.

[0035] Example 5 like Figure 2 As shown in Example 1, Example 5, an automated method for preparing nitric acid and sulfuric acid according to the present invention, is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0036] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0037] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0038] Unlike Embodiment 1, in Embodiment 5 of the present invention: the top of the waste acid tank is provided with a waste acid inlet, three probe interfaces, and one or more stirrers, and the bottom is provided with a waste acid outlet. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces; the top of the acid mixing tank is provided with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, three probe interfaces, and one or more stirrers. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet; the bottom of the acid mixing tank is provided with a substandard acid outlet and a qualified acid outlet. The substandard acid outlet is connected to the waste acid inlet in the waste acid tank, and the qualified acid outlet is connected to the production line; a nitric acid valve is provided in the nitric acid inlet, and level gauges are provided in both the nitric acid tank and the nitric acid valve. The level gauges are interlocked with the nitric acid valves for control. When the set level is reached, the nitric acid valve and the sulfuric acid valve are automatically closed.

[0039] Example 6 like Figure 2As shown in Example 1, Example 6, an automated method for preparing nitric acid and sulfuric acid according to the present invention, is implemented according to the following steps: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid (i.e., nitric acid, sulfuric acid, and water) through near-infrared spectroscopy and mixed acid chemistry. Calculate the conductivity-specific gravity of the waste acid and the data from the chemical method. Then, establish a model for nitric acid, water, and sulfuric acid, i.e., the near-infrared spectroscopy-chemical method model. The information collected by the near-infrared transmission fiber optic probe is input into the near-infrared spectroscopy-chemical method model to calculate the content of the three components nitric acid, sulfuric acid and water in the waste acid tank, that is, the near-infrared results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of the mixed acid composition (nitric acid, sulfuric acid, and water) to obtain the conductivity-specific gravity data of the waste acid and establish regression formulas for nitric acid, water, and sulfuric acid. Information collected by conductivity and specific gravity probes is used to obtain the conductivity and specific gravity results of mixed acid. The contents of nitric acid, sulfuric acid and water in the waste acid tank are calculated by regression formula, that is, the conductivity-specific gravity method results of nitric acid, sulfuric acid and water in the waste acid tank are obtained in real time. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, conductivity probes, specific gravity probes, and near-infrared fiber optic probes are used to monitor the composition of nitric acid, moisture, and sulfuric acid through dual monitoring of conductivity-specific gravity and near-infrared spectroscopy, so as to achieve accurate preparation.

[0040] Both the waste acid tank and the acid mixing tank are equipped with agitators. The agitators are kept on during the acid mixing process to maintain a homogeneous acid mixture.

[0041] If the final mixed acid is qualified, it will be transported to the production line for use as qualified acid; if it is unqualified, it will be treated as waste acid.

[0042] Unlike Embodiment 1, in Embodiment 6 of the present invention: the top of the waste acid tank is provided with a waste acid inlet, three probe interfaces, and one or more stirrers, and the bottom is provided with a waste acid outlet. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces; the top of the acid mixing tank is provided with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, three probe interfaces, and one or more stirrers. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet; the bottom of the acid mixing tank is provided with a substandard acid outlet and a qualified acid outlet. The substandard acid outlet is connected to the waste acid inlet in the waste acid tank, and the qualified acid outlet is connected to the production line; a nitric acid valve is provided in the nitric acid inlet, and level gauges are provided in the nitric acid tanks. The level gauges are interlocked with the nitric acid valves; a nitric acid valve is provided in the sulfuric acid inlet, and level gauges are provided in the sulfuric acid tanks. The level gauges are interlocked with the sulfuric acid valves; when the set level is reached, the nitric acid valve and the sulfuric acid valve are automatically closed.

Claims

1. An automated method for preparing nitric acid and sulfuric acid, characterized in that, include: Specific gravity probes, conductivity probes, and near-infrared transmission fiber optic probes were installed in both the waste acid tank and the acid mixing tank. Data collected by near-infrared transmission fiber optic probes, specific gravity probes, or conductivity probes reveals the composition of nitric acid, sulfuric acid, and water in the waste acid tank and acid mixing tank, thereby ensuring that waste acid, nitric acid, and sulfuric acid are added to the acid mixing tank in the appropriate ratio to achieve the required configuration.

2. The automated method for preparing nitric acid and sulfuric acid according to claim 1, characterized in that, The specific steps are as follows: Step 1: Install a near-infrared transmission fiber optic probe in the waste acid tank. Obtain the composition of the waste acid through near-infrared spectroscopy and mixed acid chemistry. Make data on the conductivity-specific gravity of the waste acid and the chemical method. Then establish models for nitric acid, water and sulfuric acid, i.e., near-infrared spectroscopy-chemical method model. Step 2: In the waste acid tank, use conductivity and specific gravity probes to compare the conductivity-specific gravity data with the chemical method data of mixed acid components, and establish regression formulas for nitric acid, moisture, and sulfuric acid by comparing the conductivity-specific gravity data with the chemical method data. Step 3: Using the regression formula established in Step 2, calculate the range A of the amount of nitric acid and sulfuric acid required to be added to achieve the expected qualified range for a certain amount of waste acid; Step 4: Calculate the range B of nitric acid and sulfuric acid required to be added within the expected acceptable range using the near-infrared spectroscopy-chemical model obtained in Step 1. Step 5: Take the intersection of quantity range A and quantity range B to determine the exact range of nitric acid and sulfuric acid to be added in the end; Step 6: By interlocking the liquid level with the sulfuric acid valve, set the liquid level of the added sulfuric acid. The valve will open automatically and close after the required liquid level is reached. Step 7: Set the level of added nitric acid by interlocking the liquid level with the nitric acid valve. The valve will open automatically and close after the required level is reached. Step 8: In the acid preparation tank, a conductivity probe, a specific gravity probe, and a near-infrared fiber optic probe are used to monitor the composition of nitric acid, moisture, and sulfuric acid using both conductivity-specific gravity and near-infrared spectroscopy methods, in order to achieve accurate preparation. There is stirring in the waste acid tank and the acid mixing tank; the stirring is on during the acid mixing process to keep the acid in a uniform state.

3. The automated method for preparing nitric acid and sulfuric acid according to claim 2, characterized in that, The waste acid tank is equipped with a waste acid inlet, three probe interfaces, and one or more stirrers at the top, and a waste acid outlet at the bottom. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces.

4. The automated method for preparing nitric acid and sulfuric acid according to claim 3, characterized in that, The top of the acid mixing tank is equipped with a waste acid inlet, a nitric acid inlet, a sulfuric acid inlet, three probe interfaces, and one or more stirrers. A specific gravity probe, a conductivity probe, and a near-infrared transmission fiber optic probe are respectively installed in the three probe interfaces. The nitric acid tank is connected to the nitric acid inlet, and the sulfuric acid tank is connected to the sulfuric acid inlet. The bottom of the acid mixing tank is equipped with a substandard acid outlet and a qualified acid outlet.

5. The automated method for preparing nitric acid and sulfuric acid according to claim 4, characterized in that, The outlet of the substandard acid is connected to the inlet of the waste acid tank.

6. The automated method for preparing nitric acid and sulfuric acid according to claim 5, characterized in that, A nitric acid valve is installed in the nitric acid inlet.

7. The automated method for preparing nitric acid and sulfuric acid according to claim 6, characterized in that, A sulfuric acid valve is installed in the sulfuric acid inlet.

8. The automated method for preparing nitric acid and sulfuric acid according to claim 7, characterized in that, Each of the nitric acid tanks is equipped with a level gauge, which is interlocked with the nitric acid valve.

9. The automated method for preparing nitric acid and sulfuric acid according to claim 8, characterized in that, Each sulfuric acid tank is equipped with a level gauge, which is interlocked with the sulfuric acid valve.

Images