Modeling method for a large industrial-grade sieve plate uranyl nitrate stripping column

Abstract

The present invention belongs to the technical field of uranium purification and conversion, and specifically relates to a modeling method for a large-scale industrial-grade sieve plate uranyl nitrate stripping column. Input the parameters of the pulse sieve plate stripping column, which are divided into process operation parameters and structural parameters; establish a thermodynamic model of the uranyl nitrate stripping process, establish a pulse sieve plate stripping column hydraulic model, combine the thermodynamic model of the uranyl nitrate stripping process with the pulse sieve plate stripping column hydraulic model, and solve it using the Jung Kutta method; under the premise of the process operation parameters and structural parameters of the pulse sieve plate stripping column, calculate the uranyl nitrate concentration results at the outlet of the aqueous phase and the organic phase of the pulse sieve plate stripping column; verify the calculation results, obtain the final calculation results for the output that meets the requirements, and return to calculate again for those that do not meet the requirements. The present invention is suitable for simulating the natural uranium stripping process of the pulse sieve plate stripping column. The method has high accuracy, and the simulated data are all within the error range of 8% of the actual data.

Description

Technical Field

[0001] The invention belongs to the technical field of uranium purification and conversion, and particularly relates to a modeling method for a large-scale industrial-grade sieve plate uranyl nitrate stripping column. Background Art

[0002] Solvent extraction is an important chemical separation technology, widely used in hydrometallurgy, atomic energy chemical industry, petrochemical industry, and pharmaceutical separation. Solvent extraction equipment includes mixer-settling tanks, extraction columns, and centrifugal extractors. Extraction columns are a key extraction reactor, offering advantages such as good sealing, small footprint, and high processing capacity.

[0003] The extraction and purification of natural uranium is a crucial step in the uranium purification and conversion process. Currently, the stripping process utilizes large pulsed sieve plate columns. These processes are complex, involve multiple reaction mechanisms, present numerous safety risks, and demand high quality standards, placing high demands on the on-site operational expertise of process personnel. Furthermore, due to the unique nature of the nuclear industry, changes to process conditions are strictly controlled to ensure production safety and prevent nuclear accidents such as material leaks and personal injury, preventing arbitrary exploratory changes.

[0004] To avoid these shortcomings and facilitate user experience for process engineers, it's crucial to develop a simulation system to simulate the operation of stripping columns. Currently, there are no large-scale, industrial-scale simulation systems for sieve-plate uranyl nitrate stripping columns in the uranium purification and conversion field. Furthermore, the modeling and calculation results of extraction columns used in other fields often differ significantly from actual operational results.

[0005] Therefore, this paper proposes a simulation method for a large-scale, industrial-grade sieve-plate uranyl nitrate stripping column suitable for natural uranium extraction. This method enables the establishment of a simulation system capable of exploring and optimizing process parameters, troubleshooting process problems, and training process personnel. The simulation results are within 8% of the actual results. Summary of the Invention

[0006] The purpose of the present invention is to provide a modeling method for a large-scale industrial-grade sieve plate uranyl nitrate stripping column, which can be used to simulate the operating results of a real pulse sieve plate stripping column, with an error of less than 8% from the real results, wherein the input items include two categories: one is the concentration, flow rate, acidity, temperature, etc. of the material at the aqueous phase inlet of the pulse sieve plate stripping column, and the other is the concentration, flow rate, etc. of the material at the organic phase inlet of the pulse sieve plate stripping column. Correspondingly, the output items also include two categories: one is the concentration of the material at the aqueous phase of the pulse sieve plate stripping column, and the other is the concentration of the material at the organic phase outlet of the pulse sieve plate stripping column. The modeling method has high modeling accuracy and a simple process. The model established by this method has the characteristics of optimizing process parameters, being able to control many variables, and being highly accurate.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A modeling method for a large industrial-grade sieve plate uranyl nitrate stripping column.

[0009] Step 1: Input the parameters of the pulse sieve plate stripping column, which are divided into process operation parameters and structural parameters;

[0010] Step 2: Determine whether the input parameters belong to process operation parameters or structural parameters, and input them into the corresponding receiving unit. The process operation parameters are transmitted to the process control receiving unit, and the structural parameters are transmitted to the structural parameter receiving unit.

[0011] Step 3: Model calculation: This model is composed of a thermodynamic model of the uranyl nitrate stripping process and a hydraulic model of the pulse sieve plate stripping column. The modeling process is as follows:

[0012] Establish a thermodynamic model for the uranyl nitrate stripping process:

[0013]

[0014] in,

[0015] [U] AQ ——Concentration of uranyl nitrate in the aqueous phase at the outlet of the pulsed sieve plate stripping column, gU / L;

[0016] [NO3] ORG ——Acidity of the organic phase at the inlet of the pulse sieve plate stripping column, mol / L;

[0017] [U] ORG ——Concentration of uranyl nitrate in the organic phase at the inlet of the pulsed sieve plate stripping column, gU / L;

[0018] T——reaction temperature of the pulse sieve plate stripping column during stripping, °C;

[0019] A hydraulic model of a pulse sieve plate stripping column was established, in which the dispersed phase holdup model structure is as follows:

[0020] x d =1.1*10 6 *exp[50.56*|Af-(Af) m |]*v d 0.86 *(v c +vd) 0.28 *Δρ -0.3 *ρ d - 0.93 *μ d 0.77

[0021] *α -0.56*h -0.56 *0.55

[0022]

[0023] Among them, x d ——dispersed phase holdup; Af——pulse intensity of pulse sieve plate stripping column, m / s; v d ——dispersed phase velocity, m / s; v c ——continuous phase velocity, m / s; Δρ——density difference between dispersed phase and continuous phase, kg / m 3 ρ d ——Dispersed phase density, kg / m 3 ;μ d ——dispersed phase viscosity, Pas; α——pulse sieve plate stripping column sieve plate opening ratio; γ——dispersed phase surface tension, N / m; h——pulse sieve plate stripping column sieve plate spacing, m; (Af) m ——Average pulse intensity of pulse sieve plate stripping column, m / s;

[0024] The thermodynamic model of the uranyl nitrate stripping process was combined with the hydraulic model of the pulse sieve plate stripping column and solved using the Jung-Kutta method. The uranyl nitrate concentrations at the outlets of the aqueous and organic phases of the pulse sieve plate stripping column were calculated, using the process and structural parameters of the pulse sieve plate stripping column.

[0025] Step 4: Verify the calculation results, obtain the final calculation results for the outputs that meet the requirements, and return to the calculation again for those that do not meet the requirements.

[0026] The process operating parameters include the flow rate, concentration, and acidity of the water phase inlet material of the pulse sieve plate stripping column, and the concentration and flow rate of the organic phase inlet material.

[0027] The structural parameters include the opening rate of the sieve plate of the pulse sieve plate stripping column, the sieve plate pore size, and the height and diameter of the pulse sieve plate stripping column.

[0028] By conducting extraction equilibrium tests of uranyl nitrate with stripping agents of different concentrations, the thermodynamic equilibrium data of the uranyl nitrate stripping process were obtained, the thermodynamic equilibrium equation of the uranyl nitrate stripping process was established, and the thermodynamic model of the uranyl nitrate stripping process was established through planning solution.

[0029] The thermodynamic model of uranyl nitrate stripping process is applicable to uranyl nitrate stripping process in the concentration range of 1 mg / L-450 g / L.

[0030] The beneficial effects achieved by the present invention are:

[0031] The present invention can be used to establish a multifunctional simulation system for the operation calculation of a pulsed sieve plate stripping column during the natural uranium extraction process. The advantages of the invention are:

[0032] 1) This method systematically describes a new modeling approach suitable for simulating the natural uranium stripping process using a pulsed sieve plate stripping column. The method is highly accurate, and the simulated data are within an 8% error range of the actual data.

[0033] 2) This method was used to realize the simulation software of natural uranium extraction and purification system for the first time in China. The software has high precision and is at the leading level in China.

[0034] 3) The model established by this method has many controllable variables, which can control the concentration, flow, acidity, temperature, etc. of the water phase inlet material of the pulse sieve plate stripping column, and the concentration and flow of the organic phase inlet material, which can better facilitate the operation of process personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Flowchart of the modeling approach for a large, industrial-scale sieve-plate uranyl nitrate stripping column. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1 As shown, the steps of the present invention are as follows:

[0038] Step 1: Input the parameters of the pulse sieve plate stripping column. The input parameters are divided into process operation parameters and structural parameters. The process operation parameters refer to the parameters that can be changed during the system design process to achieve process operation control, including the flow rate, concentration, and acidity of the material at the aqueous phase inlet of the pulse sieve plate stripping column, the concentration and flow rate of the material at the organic phase inlet, etc. The structural parameters refer to the parameters related to the physical structure of the pulse sieve plate stripping column, including the porosity of the sieve plate of the pulse sieve plate stripping column, the sieve plate pore size, the height, diameter and other geometric dimensions of the pulse sieve plate stripping column, etc.

[0039] Step 2: Verify and categorize the input parameters. Determine whether the input parameters are process parameters or structural parameters and enter them into the corresponding receiving unit. Process parameters are sent to the process control receiving unit, while structural parameters are sent to the structural parameter receiving unit. This prevents invalid calculations.

[0040] Step 3: Model calculation. This model is composed of a thermodynamic model of the uranyl nitrate stripping process and a hydraulic model of a pulse sieve plate stripping column, rather than a traditional single thermodynamic model theoretical calculation. Therefore, it can be used for the simulation of industrial-grade pulse sieve plate stripping columns, and the calculation results are more accurate. During the calculation process, in order to ensure that the calculation results are more in line with industrial reality and have smaller errors, two main methods are adopted: one is to achieve accurate simulation calculations of pulse sieve plate stripping columns through dual correction of thermodynamic models and hydraulic models. The second is to use the differential unit method for calculation, that is, to perform differential processing on the reaction section of the pulse baffle column, and then adopt the overall integration method to realize the calculation of the entire section, thereby improving the accuracy of the simulation.

[0041] The modeling process is as follows:

[0042] 1) First, a thermodynamic model for the stripping process of uranyl nitrate solution was established. By conducting extraction equilibrium tests with uranyl nitrate and stripping agents of varying concentrations, thermodynamic equilibrium data for the stripping process was obtained, and a thermodynamic equilibrium equation for the stripping process was established. A thermodynamic model for the stripping process was then established through program solving. This model, unique to this patent, is applicable to the stripping process of uranyl nitrate in a concentration range of 1 mg / L to 450 g / L. The specific model is as follows:

[0043]

[0044] in,

[0045] [U] AQ ——Concentration of uranyl nitrate in the aqueous phase at the outlet of the pulsed sieve plate stripping column, gU / L;

[0046] [NO3] ORG ——Acidity of the organic phase at the inlet of the pulse sieve plate stripping column, mol / L;

[0047] [U] ORG ——Concentration of uranyl nitrate in the organic phase at the inlet of the pulsed sieve plate stripping column, gU / L;

[0048] T——Reaction temperature of the pulse sieve plate stripping column stripping process, ℃.

[0049] 2) Establish a hydraulic model for a pulsed sieve plate stripping column. During the establishment of the hydraulic model for a pulsed sieve plate stripping column, the hydraulic model was optimized to ensure that it is more suitable for the sieve plate column structure. The structure of the dispersed phase holdup model is as follows:

[0050] x d =1.1*10 6 *exp[50.56*|Af-(Af) m |]*v d 0.86 *(vc +v d ) 0.28 *Δρ -0.3 *ρ d -0.93 *μ d 0.77

[0051] *α -0.56 *h -0.56 *0.55

[0052]

[0053] Among them, x d ——dispersed phase holdup; Af——pulse intensity of pulse sieve plate stripping column m / s; v d ——dispersed phase velocity m / s; v c ——continuous phase velocity m / s; Δρ——density difference between dispersed phase and continuous phase, kg / m 3 ρ d ——Dispersed phase density, kg / m 3 ;μ d ——dispersed phase viscosity, Pas; α——pulse sieve plate stripping column sieve plate opening ratio; γ——dispersed phase surface tension, N / m; h——pulse sieve plate stripping column sieve plate spacing, m; (Af) m ——Average pulse intensity of pulse sieve plate stripping column m / s.

[0054] 3) After completing the thermodynamic model of the uranyl nitrate stripping process and the hydraulic model of the pulsed sieve plate stripping column, the two were combined and solved using the Jung-Kutta method. The uranyl nitrate concentrations at the outlets of the aqueous and organic phases of the pulsed sieve plate stripping column were calculated, using the operating and structural parameters of the pulsed sieve plate stripping column.

[0055] Step 4: After the calculation is completed, the calculation results are verified. For the output that meets the requirements, the final calculation results are obtained. For those that do not meet the requirements, they are returned to the model calculation unit for recalculation.

Claims

1. A modeling method for a large-scale industrial-grade sieve plate uranyl nitrate stripping column, characterized by: Step 1: Input the parameters of the pulse sieve plate stripping column, which are divided into process operation parameters and structural parameters; Step 2: Determine whether the input parameters belong to process operation parameters or structural parameters, and input them into the corresponding receiving unit. The process operation parameters are transmitted to the process control receiving unit, and the structural parameters are transmitted to the structural parameter receiving unit. Step 3: Model calculation: This model is composed of a thermodynamic model of the uranyl nitrate stripping process and a hydraulic model of the pulse sieve plate stripping column. The modeling process is as follows: Establish a thermodynamic model for the uranyl nitrate stripping process: in, [U] AQ ——Concentration of uranyl nitrate in the aqueous phase at the outlet of the pulsed sieve plate stripping column, gU / L; [NO3] ORG ——Acidity of the organic phase at the inlet of the pulse sieve plate stripping column, mol / L; [U] ORG ——Concentration of uranyl nitrate in the organic phase at the inlet of the pulsed sieve plate stripping column, gU / L; T——reaction temperature of the pulse sieve plate stripping column during stripping, °C; A hydraulic model of a pulse sieve plate stripping column was established, in which the dispersed phase holdup model structure is as follows: x d =1.1*10 6 *exp[50.56*|Off-(Off) m |]*v d 0.86 *(v c +v d ) 0.28 *Δρ -0.3 *ρ d -0.93 *μ d 0.77 *α -0.56 *h -0.56 *0.55 Among them, x d ——dispersed phase holdup; Af——pulse intensity of pulse sieve plate stripping column, m / s; v d ——dispersed phase velocity, m / s; v c ——continuous phase velocity, m / s; △ρ——density difference between dispersed phase and continuous phase, kg / m 3 ρ d ——Dispersed phase density, kg / m 3 ;μ d ——dispersed phase viscosity, Pas; α——pulse sieve plate stripping column sieve plate opening ratio; γ——dispersed phase surface tension, N / m; h——pulse sieve plate stripping column sieve plate spacing, m; (Af) m ——Average pulse intensity of pulse sieve plate stripping column, m / s; The thermodynamic model of the uranyl nitrate stripping process was combined with the hydraulic model of the pulse sieve plate stripping column and solved using the Jung-Kutta method. The uranyl nitrate concentrations at the outlets of the aqueous and organic phases of the pulse sieve plate stripping column were calculated, using the process and structural parameters of the pulse sieve plate stripping column. Step 4: Verify the calculation results, obtain the final calculation results for the outputs that meet the requirements, and return to the calculation again for those that do not meet the requirements; The process operating parameters include the flow rate, concentration, and acidity of the aqueous phase inlet material of the pulse sieve plate stripping column, and the concentration and flow rate of the organic phase inlet material; the structural parameters include the porosity of the pulse sieve plate stripping column, the sieve plate pore size, and the height and diameter of the pulse sieve plate stripping column; the thermodynamic model of the uranyl nitrate stripping process is applicable to the uranyl nitrate stripping process in the concentration range of 1 mg / L-450 g / L.

2. The modeling method of the large-scale industrial-grade sieve plate uranyl nitrate stripping column according to claim 1, characterized in that: By conducting extraction equilibrium tests of uranyl nitrate with stripping agents of different concentrations, the thermodynamic equilibrium data of the uranyl nitrate stripping process were obtained, the thermodynamic equilibrium equation of the uranyl nitrate stripping process was established, and the thermodynamic model of the uranyl nitrate stripping process was established through planning solution.

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