Device for stably and controllably adding iron powder in acidolysis process in titanium dioxide production
By using a metering and weighing screw and a DCS control system, combined with a screw speed sensor and a frequency converter, the problem of controlling the iron powder addition speed was solved, achieving stable reaction and cost control in the titanium dioxide production process.
Patent Information
- Application Number
- CN202520165173.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-01-24
AI Technical Summary
In the production of titanium dioxide, the rate at which iron powder is added is difficult to control, leading to unstable reaction temperature, which affects product quality and increases costs.
By employing a metering and weighing screw and a DCS control system, combined with a screw speed sensor and a frequency converter, the addition speed and amount of iron powder are precisely controlled. The motor speed is adjusted by the screw frequency converter to achieve stable and controllable addition of iron powder.
This method enables precise addition of iron powder, stabilizes the reaction temperature, improves the product quality of titanium dioxide, and reduces costs.
Smart Images
Figure CN223861802U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a device, specifically a device for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production. Background Technology
[0002] In the sulfuric acid process for titanium dioxide production, the acidolysis reaction of ilmenite is the first chemical reaction. This involves adding crushed ilmenite powder to concentrated sulfuric acid, decomposing the titanium dioxide and other reactant components into sulfates, including ferric sulfate and ferrous sulfate. Ferrous sulfate is relatively stable under acidic conditions, with ferrous hydroxide precipitating only when the pH is above 5. Ferric sulfate is stable only in strongly acidic environments, hydrolyzing to form ferric hydroxide when the pH is above 2. Iron hydroxides are extremely detrimental to titanium dioxide production, especially during hydrolysis, as they precipitate with metatitanic acid and remain in the metatitanic acid, severely affecting the quality of the finished titanium dioxide. To prevent the formation of ferric ions in subsequent production, all ferric ions in the titanium solution must be reduced to ferrous ions, and an excess of reducing agent must be used to further reduce some tetravalent titanium to trivalent titanium, ensuring the absence of ferric ions.
[0003] In actual production, iron powder is chosen as the reducing agent because it has a large specific surface area, resulting in a faster reaction rate. Therefore, the addition rate of iron powder must be strictly controlled to prevent excessive temperature rise in the titanium liquid, especially in summer. Since purchased iron powder is added in ton-bag packages, the addition rate is difficult to control, affecting not only the reaction temperature but also increasing costs due to the difficulty in controlling the dosage. Utility Model Content
[0004] To address the aforementioned problems, this invention provides a device for the stable and controllable addition of iron powder during the acidolysis process in titanium dioxide production.
[0005] The technical solution adopted by this utility model is as follows:
[0006] A device for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production includes a metering and weighing screw and a DCS control system. The metering and weighing screw is equipped with a screw weighing sensor and a screw speed sensor. The screw weighing sensor is used to detect the weight of the iron powder and transmit the weighing signal to the DCS control system. The screw speed sensor is used to detect the rotational speed of the metering and weighing screw and transmit the rotational speed signal to the DCS control system. The metering and weighing screw is connected to a screw frequency converter for controlling the motor of the metering and weighing screw and adjusting the motor speed. The screw frequency converter is connected to the DCS control system.
[0007] Furthermore, the weighing auger is connected to the iron powder hopper above via a flexible connection; and is sequentially connected to the acid hydrolysis tank, settling tank, and freezing separation tank below.
[0008] Furthermore, the flexible connectors are made of wear-resistant materials.
[0009] Furthermore, the blades of the weighing auger are made of stainless steel.
[0010] Purchased iron powder is fed into the iron powder hopper via a crane, and a flexible connection connects the iron powder to the weighing screw. The iron powder is then fed into the acid hydrolysis tank via the screw's weighing mechanism. The load cell of the weighing screw transmits the weighing signal to the DCS (Distributed Control System), and the speed sensor transmits the speed signal to the DCS control system. The screw motor is controlled by a frequency converter. This device allows the DCS system to input the iron powder feeding rate (e.g., 0.8 t / h), and this signal is used to adjust the frequency converter for precise feeding.
[0011] Beneficial effects:
[0012] This utility model relates to a device for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production. By controlling the rotation of the screw motor through a frequency converter, the addition speed of iron powder can be precisely controlled. Attached Figure Description
[0013] Figure 1 This is an assembly diagram of the present invention;
[0014] In the diagram, 1. Weighing screw, 2. Iron powder hopper, 3. Flexible connection, 4. Acid hydrolysis tank, 5. Screw weighing sensor, 6. Screw speed sensor, 7. Screw frequency converter, 8. DCS control system. Detailed Implementation
[0015] The present invention will be further described below with reference to the accompanying drawings.
[0016] A device for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production includes a weighing screw 1 and a DCS control system 8. The weighing screw is equipped with a screw weighing sensor 5 and a screw speed sensor 6. The screw weighing sensor is used to detect the weight of the iron powder and transmit the weighing signal to the DCS control system. The screw speed sensor is used to detect the rotational speed of the weighing screw and transmit the rotational speed signal to the DCS control system. The weighing screw is connected to a screw frequency converter 7 to control the motor of the weighing screw and adjust the motor speed. The screw frequency converter is connected to the DCS control system.
[0017] The weighing screw is connected to the iron powder hopper 2 above via a flexible connection 3; and is connected to the acid hydrolysis tank 4, sedimentation tank 9, and freeze separation tank 10 below in sequence. After acid hydrolysis, sedimentation occurs, and the residue is separated. Then, TiOSO4 freeze separation is performed for further concentration.
[0018] The blades of the weighing auger are made of stainless steel.
[0019] Purchased iron powder is fed into the iron powder hopper via a crane, and a flexible connection connects the iron powder to the weighing screw. The iron powder is then fed into the acid hydrolysis tank via the screw's weighing mechanism. The load cell of the weighing screw transmits the weighing signal to the DCS (Distributed Control System), and the speed sensor transmits the speed signal to the DCS control system. The screw motor is controlled by a frequency converter. This device allows the DCS system to input the iron powder feeding rate (e.g., 0.8 t / h), and this signal is used to adjust the frequency converter for precise feeding.
Claims
1. A device for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production, comprising a metering and weighing screw (1) and a DCS control system (8), characterized in that, The weighing screw is equipped with a screw weighing sensor (5) and a screw speed sensor (6). The screw weighing sensor is used to detect the weight of the iron powder and transmit the weighing signal to the DCS control system. The screw speed sensor is used to detect the speed of the weighing screw and transmit the speed signal to the DCS control system. The weighing screw is connected to a screw frequency converter (7) to control the motor of the weighing screw and adjust the speed of the motor. The screw frequency converter is connected to the DCS control system.
2. The apparatus for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production according to claim 1, characterized in that, The weighing screw is connected to the iron powder hopper (2) above by a flexible connection (3); and is connected to the acid hydrolysis tank (4), sedimentation tank (9), and freezing separation tank (10) below in sequence.
3. The apparatus for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production according to claim 2, characterized in that, The flexible connector is made of wear-resistant material.
4. The apparatus for the stable and controllable addition of iron powder in the acidolysis process of titanium dioxide production according to claim 2, characterized in that, The blades of the weighing auger are made of stainless steel.