Method for reducing iron in vanadium production raw material fine slag

Abstract

The present application relates to a kind of vanadium production raw material fine slag reduces iron method, using iron removal equipment, remove the visible iron in vanadium slag block, vanadium slag block enters ball mill after grinding, after grinding, fine slag is removed iron particle in fine slag by winnowing, cylinder screen.The rotational speed of winnowing machine, cylinder screen is automatically adjusted according to the weight (powder) of ball mill discharge belt fine slag, ensure the screening effect of winnowing machine, cylinder screen, remove the iron particle in fine slag to the maximum, provide high-quality fine slag raw material for roasting rotary kiln, and further ensure the vanadium conversion rate of roasting rotary kiln.Secondary model calculates the rotational speed of winnowing machine, cylinder screen according to the weight (powder) of fine slag, the rotational speed of winnowing machine, cylinder screen, the speed setting of frequency converter is automatically adjusted by primary system according to the rotational speed of winnowing machine, cylinder screen issued by secondary;Background records the weight (powder) of fine slag, the rotational speed of winnowing machine, cylinder screen, the weight (powder) of fine slag into roasting rotary kiln, vanadium slag grade, fine slag iron content and other data, guide secondary model optimization self-learning.

Description

Technical Field

[0001] This patent application belongs to the technical field of vanadium production methods, and more specifically, it relates to a method for reducing iron content in vanadium production raw material slag. Background Technology

[0002] Vanadium is a rare metal, and vanadium pentoxide tablets are the main vanadium raw material in the vanadium market. Chengde Vanadium Titanium New Materials Co., Ltd.'s Vanadium Titanium Division is a large-scale vanadium chemical enterprise primarily producing vanadium pentoxide. Vanadium slag is the main raw material for vanadium pentoxide production. In the batching process, based on the varying vanadium content of the raw vanadium slag, the vanadium slag raw material in the intermediate powder silo is weighed and mixed evenly with soda ash in a mixer according to the process requirements. This mixture is then sent to a homogenization silo for homogenization, moistened with saturated brine, and then fed into the rotary kiln's feed hopper via a bucket elevator. The rotary kiln uses mixed gas as fuel, and the material inside is roasted in an oxidizing atmosphere. The roasting process is a continuous process from low temperature to high temperature, followed by gradual cooling. The iron content of the refined slag is a crucial factor affecting the consumption of raw materials and the rotary kiln's conversion rate.

[0003] The current production process cannot efficiently and reasonably calculate the optimization settings of control parameters, cannot guarantee the precise proportion of raw materials in the rotary kiln for sodium roasting, thus resulting in high consumption of raw and auxiliary materials, failure to reduce the iron content of the raw material slag, and failure to ensure the vanadium conversion rate of the rotary kiln. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for reducing the iron content of vanadium production raw material slag, which can minimize the iron content of the raw material slag and ensure the vanadium conversion rate of the sodium roasting rotary kiln.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: A method for reducing iron content in vanadium production raw material refined slag involves vanadium slag and refined slag. The vanadium slag is in block form, and the refined slag is in powder form. The method includes the following steps: S1. Determine the conveying and metering method for vanadium slag: Vanadium slag is conveyed and metered by belt scale. The belt scale is calibrated by physical calibration, and the weight of vanadium slag (in block form) is used as the initial parameter. S2. Using database access technology, real-time data collection is achieved for vanadium slag weight (lumpy), vanadium slag grade, vanadium content of raw vanadium slag, soda ash grade, iron content of refined slag, and actual weight of refined slag, as well as rotary kiln conversion rate data collection. S3. Use iron removal equipment to remove the exposed iron in the vanadium slag blocks: The iron removal equipment is a ball mill. The weight (block shape) of the vanadium slag entering the ball mill is entered on the monitoring screen. The first-level automation system adjusts the speed of the ball mill belt according to the weight (block shape) of the vanadium slag, so that the actual weight (block shape) of the vanadium slag is close to the set weight. S4. The secondary model calculates the rotation speed of the air classifier and cylindrical screen after the ball milling process based on the actual weight of the vanadium slag (lumpy), and sends the rotation speed set value to the primary automation system. S5. Vanadium slag (lumpy) is ground into powder in a ball mill. The powdered slag is then screened by an air classifier and a cylindrical screen to remove iron particles to the maximum extent. The powdered slag is then fed into a calcining rotary kiln via a screw conveyor and belt scale. S6. The secondary model calculates the optimal temperature setpoint of the rotary kiln based on the actual weight and iron content of the refined slag (powder), combined with the alkali ratio (the secondary model is a matching model of the pre-set refined slag weight, iron content, alkali ratio, rotary kiln temperature, and large kiln conversion rate process curve), and sends it to the primary automation system. The primary automation system adjusts the opening of the gas valve and air distribution valve through PID control to make the actual temperature of the rotary kiln infinitely close to the set temperature. S7, the second-level model continuously optimizes through self-learning.

[0006] Furthermore, in S2, database access technologies include ORM frameworks, MyBatis, MySQL, Hibernate, or Spring Data JPA.

[0007] Furthermore, in S2, the vanadium slag grade is 12.1%, the vanadium content of the raw vanadium slag is 7.0%, and the soda ash grade is 98.8%.

[0008] Furthermore, in S3, the primary automation system is a primary DCS control system. The set value of the vanadium slag weight (lumpy) in the ball mill is entered into the monitoring screen as 28 tons / hour. The primary DCS control system adjusts the ball mill belt speed to 6.5 meters / second according to the set value of the vanadium slag weight (lumpy). The speed parameter of the frequency converter matched with the ball mill belt is set to 40 Hz. The actual vanadium slag weight (lumpy) is 27.4 tons / hour, which is close to the set weight.

[0009] Furthermore, in S4, the rotational speed of the air classifier and the cylindrical screen are both set to 33.3 Hz. The specific calculation method is as follows: the air classifier's throughput is 0-45 t / h, with variable frequency drive and a main shaft speed of 0-300 r / min (inverter frequency 0-50 Hz). When the inverter frequency of the cylindrical screen is the same as that of the air classifier's motor inverter, the throughput of the cylindrical screen matches that of the air classifier, ensuring that the vanadium slag passes smoothly through both the air classifier and the cylindrical screen. When the weight of vanadium slag (lumpy) entering the ball mill is 30 tons / hour, the inverter frequency of the air classifier is 30 / 45*50=33.3 Hz, and the inverter frequency of the cylindrical screen is also 33.3 Hz.

[0010] Furthermore, in S5, "maximum removal of iron particles" means that the iron content of the refined slag (powder) is less than or equal to 2%.

[0011] Furthermore, in S7, "secondary model continuous optimization self-learning" refers to the following: the background records data such as the grade of vanadium slag (lumpy), the weight of vanadium slag (lumpy), the rotation speed of the air classifier and the cylindrical screen, the weight of refined slag (powder), the iron content in the refined slag, the alkali ratio and the conversion rate of the large kiln, etc., to guide the secondary model to continuously optimize self-learning, adjust the corresponding curve settings according to the actual process indicators, and continuously improve the adaptability of the process curve.

[0012] Furthermore, the "secondary model" specifically refers to the process curve matching model.

[0013] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are: The primary automation system and the secondary model are organically combined. The primary system is responsible for collecting actual parameters, receiving commands from the secondary model and executing them precisely. The secondary model performs tracking logic control and model calculations, tracks materials for raw material batching and roasting processes, and collects and processes measured data. Through a series of mathematical models and control algorithms, it optimizes and calculates various control parameters and transmits them to the primary automation level to achieve direct control of production. This ensures accurate raw material ratios in the sodium roasting rotary kiln, reduces raw material consumption, minimizes iron content in refined slag, and ensures vanadium conversion rate in the rotary kiln. Attached Figure Description

[0014] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the embodiments.

[0016] A method for reducing iron content in vanadium production raw material slag, such as Figure 1 The process includes the following steps: S1. Determine the conveying and metering method for vanadium slag: The vanadium slag is conveyed and metered by a belt scale. The belt scale is calibrated by physical calibration, and the weight of the vanadium slag (in block form) is used as the initial parameter.

[0017] S2. Utilize database access technology to achieve real-time data acquisition of vanadium slag weight (lumpy), vanadium slag grade, vanadium content of raw vanadium slag, soda ash grade, iron content of refined slag, and actual weight of refined slag, as well as rotary kiln conversion rate data acquisition. Database access technologies include ORM frameworks, MyBatis, MySQL, Hibernate, or Spring Data JPA. In this step, the vanadium slag grade is 12.1%, the raw vanadium slag vanadium content is 7.0%, and the soda ash grade is 98.8%.

[0018] S3. Use iron removal equipment to remove exposed iron from vanadium slag blocks: The iron removal equipment is a ball mill. The weight (block shape) of the vanadium slag entering the ball mill is entered on the monitoring screen. The first-level automation system adjusts the speed of the ball mill belt according to the weight (block shape) of the vanadium slag, so that the actual weight (block shape) of the vanadium slag is close to the set weight.

[0019] The primary automation system is a primary DCS control system. The set value of vanadium slag weight (lumpy) in the ball mill is entered into the monitoring screen as 28 tons / hour. The primary DCS control system adjusts the ball mill belt speed to 6.5 meters / second according to the set value of vanadium slag weight (lumpy). The speed parameter of the frequency converter matched with the ball mill belt is set to 40 Hz. The actual vanadium slag weight (lumpy) is 27.4 tons / hour, which is close to the set weight.

[0020] S4. The secondary model calculates the rotational speeds of the air classifier and cylindrical screen after the ball milling process based on the actual weight of the vanadium slag (lumpy). These rotational speed settings are then sent to the primary automation system. The specific calculation method is as follows: the air classifier's capacity is 0-45 t / h, with frequency conversion drive and a main shaft speed of 0-300 r / min (frequency converter frequency 0-50 Hz). When the frequency converter frequency of the cylindrical screen matches the frequency converter frequency of the air classifier's motor, the processing capacity of the cylindrical screen matches that of the air classifier, ensuring the vanadium slag passes smoothly through both the air classifier and the cylindrical screen. When the weight of the vanadium slag (lumpy) entering the ball mill is 30 tons / hour, the frequency converter frequency of the air classifier is 30 / 45*50=33.3 Hz, and the frequency converter frequency of the cylindrical screen is also 33.3 Hz.

[0021] S5. Vanadium slag (lumpy) is ground into powder in a ball mill. The powdered slag is then screened by an air classifier and a cylindrical screen to remove iron particles to the maximum extent. The powdered slag is then fed into a rotary kiln for calcination via a screw conveyor and belt scale. Removing iron particles to the maximum extent means that the iron content of the powdered slag is less than or equal to 2%.

[0022] S6. The secondary model calculates the optimal temperature setpoint of the rotary kiln based on the actual weight and iron content of the refined slag (powder), combined with the alkali ratio (the secondary model is a matching model of the pre-set refined slag weight, iron content, alkali ratio, rotary kiln temperature, and large kiln conversion rate process curve), and sends it to the primary automation system. The primary automation system adjusts the opening of the gas valve and air distribution valve through PID control to make the actual temperature of the rotary kiln infinitely close to the set temperature. S7. The secondary model continuously optimizes and learns, specifically referring to the following: the background records data such as the grade of vanadium slag (lumpy), the weight of vanadium slag (lumpy), the rotation speed of the air classifier and cylindrical screen, the weight of refined slag (powder), the iron content in the refined slag, the alkali ratio, and the conversion rate of the large kiln. This data guides the secondary model to continuously optimize and learn, adjusting the corresponding curve settings according to the actual process indicators, and continuously improving the adaptability of the process curves. The "secondary model" specifically refers to the process curve matching model.

[0023] (1) Vanadium slag is conveyed and metered using a belt scale. The belt scale is calibrated by physical calibration, with the weight of the vanadium slag (in block form) as the initial parameter.

[0024] (2) Using database access technology, real-time data collection of vanadium slag weight (block), vanadium slag grade, iron content of refined slag and actual weight of refined slag, as well as rotary kiln conversion rate data collection are realized.

[0025] (3) Enter the set value of vanadium slag weight (block) in the ball mill on the monitoring screen. The first-level automation system adjusts the speed of the ball mill belt according to the set value of vanadium slag weight (block) so that the actual weight of vanadium slag (block) is close to the set weight.

[0026] (4) The secondary model calculates the rotation speed of the air classifier and the cylindrical screen after ball milling based on the vanadium slag grade and the actual weight of the vanadium slag (block), and sends the rotation speed setting value to the primary automation system.

[0027] (5) Vanadium slag (lumpy) is ground into powdered slag in a ball mill. The slag is then screened by an air classifier and a cylindrical screen to remove iron particles to the maximum extent. The slag (powdered) is then fed into the calcining rotary kiln via a screw conveyor and belt scale.

[0028] (6) The secondary model calculates the rotary kiln temperature setpoint based on the actual weight and iron content of the refined slag (powder) and the alkali ratio, and sends it to the primary automation system. The primary automation system adjusts the opening of the gas valve and the air distribution valve through PID control so that the actual temperature of the rotary kiln is infinitely close to the set temperature.

[0029] (7) The second-level model continuously optimizes itself through self-learning.

[0030] The secondary model calculates the rotation speed of the air separator and cylindrical screen based on the weight of the refined slag (powdered), the rotation speed of the air separator and cylindrical screen, and the primary system automatically adjusts the speed setting of the frequency converter based on the rotation speed of the air separator and cylindrical screen issued by the secondary system. The background records data such as the weight of the refined slag (powdered), the rotation speed of the air separator and cylindrical screen, the weight of the refined slag (powdered) entering the calcining rotary kiln, the vanadium slag grade, and the iron content of the refined slag, which guides the secondary model to optimize self-learning and can generate production reports. The production reports are generated in conjunction with the production line.

[0031] In steps (4) and (6), the first-level DCS control system adjusts and controls the actuators to achieve precise material proportioning. The adjustment and control includes the output speed of the frequency converter or the adjustment of the valve opening.

[0032] In step (7), the background records data such as the grade of vanadium slag (block), the weight of vanadium slag (block), the rotation speed of the air classifier and the cylindrical screen, the weight of refined slag (powder), the iron content in the refined slag, the alkali ratio and the conversion rate of the large kiln, so as to guide the second-level model to continuously optimize self-learning and generate production reports. Example

[0033] 1. The secondary model, through database collection, found that the vanadium slag grade entering the plant was 12.1%, and obtained that the raw vanadium slag contained 7.0% vanadium and the soda ash grade was 98.8%.

[0034] 2. The ball mill is set to a weight of vanadium slag (lumpy) that is entered into the monitoring screen as 28 tons / hour. The first-level automation system adjusts the ball mill belt speed to 6.5 m / s according to the weight of vanadium slag (lumpy) and the frequency converter speed parameter is set to 40 Hz. The actual weight of vanadium slag (lumpy) is close to the set weight, which is 27.4 tons / hour.

[0035] 3. Based on the actual weight of vanadium slag (lumpy) of 27.4 tons / hour and the vanadium slag grade of 12.1%, the secondary model calculates that the speed of the air separator and the speed of the cylindrical screen are set to 30.44 Hz.

[0036] 4. The primary automation system sets the speed of the air separator and the cylindrical screen to 30.44 Hz based on the secondary model, and adjusts the actual speed of the frequency converters of the air separator and the cylindrical screen to 30 Hz.

[0037] 5. After air separation and sieving, the iron content of the refined slag (powder) was measured to be 1.95. The laboratory personnel entered the data, and the secondary model collected this data. At the same time, the belt scale data of the refined slag (powder) entering the rotary kiln was collected, the secondary slag ratio (manually entered), combined with the alkali ratio of 1.2, the rotary kiln temperature control (650 degrees) was calculated and sent to the primary automation system.

[0038] 6. The primary automation system executes PID control based on instructions from the secondary system. The controlled variable is the rotary kiln temperature, and the controlled variables are the opening degrees of the gas regulating valve and the air distribution regulating valve. Due to changes in the calorific value of the gas, the opening degrees of the gas regulating valve and the air distribution regulating valve are adjusted in real time to keep the rotary kiln temperature as close as possible to the set temperature.

[0039] Because the oxidation of metallic iron is highly exothermic, it can easily cause a bright ring to form in the preheating zone. The overall temperature should ideally be kept within the midline, and the preheating zone temperature must be strictly controlled to ensure a proper oxidizing atmosphere. The roasting process involves strictly controlling the preheating zone temperature based on the iron content in the refined slag raw material; adjusting the amount of secondary slag added; and dynamically adjusting the amount of secondary slag added based on changes in the vanadium slag grade. A low alkali ratio is used in the roasting process to reduce the formation of low-melting-point substances.

[0040] The vanadium slag grade is 12.1%, the soda ash grade is 98.8%, the actual weight of vanadium slag (lumpy) is 27.4 tons / hour, the air classifier speed is set to 30.44 Hz, the cylindrical screen speed is set to 30.44 Hz, the iron content of the refined slag (powder) is 1.95%, the alkali ratio is set to 1.20, and the secondary model combined with the calorific value of the gas is used to calculate and set the rotary kiln temperature control to 650 degrees, the gas regulating valve opening to 65%, and the air regulating valve opening to 70%. At this time, the rotary kiln conversion rate is 85.6%, which is good.

[0041] The vanadium slag grade is 12.3%, the soda ash grade is 98.5%, and the vanadium slag (lumpy) weight is 21.5 tons / hour. The air classifier speed is set to 19.35 Hz, and the cylindrical screen speed is set to 19.35 Hz. During operation, it was found that the cylindrical screen was pressing down, triggering the motor overload protection. After investigation, it was found that the vanadium slag belt scale sensor signal line was broken, causing the weighing sensor signal to be distorted. This resulted in the belt scale reading a lower weight than the actual weight, and the air classifier and cylindrical screen speeds were too low, causing the refined slag to accumulate inside the cylindrical screen.

[0042] As can be seen, the secondary model of this invention calculates the rotational speed of the air classifier and cylindrical screen after ball milling based on the vanadium slag grade and the actual weight of the vanadium slag (lumpy), and sends the rotational speed setpoint to the primary automation system. The primary automation system controls and adjusts the inverter speed to make the actual rotational speed infinitely close to the set speed. After the vanadium slag (lumpy) is ground in the ball mill, air-classified by the air classifier, and screened by the cylindrical screen, metallic iron is removed to the maximum extent. The refined slag (powder) is continuously conveyed to the calcining rotary kiln by a screw and belt. The secondary model then calculates the rotary kiln temperature setpoint based on the actual weight of the refined slag (powder), iron content, and alkali ratio, and sends it to the primary automation system. The primary automation system adjusts the opening of the gas valve and air distribution valve through PID control to make the actual temperature of the rotary kiln infinitely close to the set temperature.

[0043] The system organically combines a primary automation system and a secondary model. The primary system is responsible for collecting actual parameters, receiving commands from the secondary model, and executing them precisely. The secondary model performs tracking logic control and model calculations, tracks materials for raw material batching and roasting processes, and collects and processes measured data. Through a series of mathematical models and control algorithms, it optimizes and calculates various control parameters and transmits them to the primary automation level for direct control of production. This ensures precise proportioning of raw materials in the sodium roasting rotary kiln, reduces the consumption of raw and auxiliary materials, minimizes the iron content in the refined slag, and ensures the vanadium conversion rate of the rotary kiln, effectively solving the aforementioned problems in the background technology.

[0044] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for reducing iron content in vanadium production raw material refined slag, involving vanadium slag and refined slag, wherein the vanadium slag is in block form and the refined slag is in powder form, characterized in that: Includes the following steps, S1. Determine the conveying and metering method for vanadium slag: Vanadium slag is conveyed and metered by belt scale. The belt scale is calibrated by physical calibration, and the weight of vanadium slag is used as the initial parameter. S2. Using database access technology, real-time data collection is achieved for vanadium slag weight, vanadium slag grade, vanadium content of raw vanadium slag, soda ash grade, iron content of refined slag, and actual weight of refined slag, as well as rotary kiln conversion rate data collection. S3. Use iron removal equipment to remove the exposed iron in the vanadium slag: The iron removal equipment is a ball mill. The weight setting value of the vanadium slag entering the ball mill is entered on the monitoring screen. The first-level automation system adjusts the speed of the ball mill belt according to the weight setting value of the vanadium slag so that the actual weight of the vanadium slag is close to the set weight. S4. The secondary model calculates the rotation speed of the air classifier and cylindrical screen after the ball milling process based on the actual weight of the vanadium slag, and uses it as the rotation speed setpoint. The rotation speed setpoint is then sent to the primary automation system. S5. Vanadium slag is ground into powder in a ball mill. After being screened by an air classifier and a cylindrical screen, iron particles are removed to the maximum extent. The powdered slag is then fed into a calcining rotary kiln via a screw conveyor and belt scale. S6. The secondary model calculates the optimal temperature setpoint of the rotary kiln based on the actual weight and iron content of the refined slag and the alkali ratio, and sends it to the primary automation system. The primary automation system adjusts the opening of the gas valve and air distribution valve through PID control so that the actual temperature of the rotary kiln is infinitely close to the set temperature. S7, the second-level model continuously optimizes through self-learning.

2. The method for reducing iron content in vanadium production raw material slag according to claim 1, characterized in that: In S2, database access technologies include ORM frameworks, MyBatis, MySQL, Hibernate, or Spring Data JPA.

3. The method for reducing iron content in vanadium production raw material slag according to claim 2, characterized in that: In S2, the vanadium slag grade is 12.1%, the vanadium content of the raw vanadium slag is 7.0%, and the soda ash grade is 98.8%.

4. The method for reducing iron content in vanadium production raw material slag according to claim 3, characterized in that: In S3, the primary automation system is the primary DCS control system. The set value of vanadium slag weight in the ball mill is entered into the monitoring screen as 28 tons / hour. The primary DCS control system adjusts the speed of the ball mill belt to 6.5 meters / second according to the set value of vanadium slag weight. The speed parameter of the frequency converter matched with the ball mill belt is set to 40 Hz. The actual weight of vanadium slag is 27.4 tons / hour, which is close to the set weight.

5. The method for reducing iron content in vanadium production raw material slag according to claim 4, characterized in that: In S4, the speed of the air separator and the speed of the cylindrical screen are both set to 33.3 Hz.

6. The method for reducing iron content in vanadium production raw material slag according to claim 5, characterized in that: In S5, "maximum removal of iron particles" means that the iron content of the refined slag is less than or equal to 2%.

7. A method for reducing iron content in vanadium production raw material slag according to any one of claims 1-6, characterized in that: In S7, "secondary model continuous optimization self-learning" refers to the following: the background records data such as vanadium slag grade, vanadium slag weight, rotation speed of air classifier and cylindrical screen, refined slag weight, iron content in refined slag, alkali ratio and conversion rate of large kiln, etc., to guide the secondary model to continuously optimize self-learning, adjust the corresponding curve settings according to the actual process indicators, and continuously improve the adaptability of process curves.

8. A method for reducing iron content in vanadium production raw material slag according to any one of claims 1-6, characterized in that: The "secondary model" specifically refers to the process curve matching model.

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