Continuous treatment process for titanium tetrachloride refined vanadium removal slurry and induction furnace system

Abstract

The invention relates to the technical field of metallurgical environmental protection, in particular to a continuous treatment process for titanium tetrachloride refined vanadium removal slurry and an induction furnace system. The continuous treatment process comprises the following steps: continuously and uniformly introducing the organic matter refined vanadium removal slurry into an induction furnace through a feeding control device; an alternating magnetic field generated by an induction furnace is utilized to enable conductive components in the organic matter refined vanadium removal slurry to generate eddy current heating, so that the slurry is heated to be above the boiling point of a titanium tetrachloride solvent, and rapid evaporation and solid-liquid separation of the solvent are realized; the evaporated titanium tetrachloride steam is guided into a condensation system to be condensed and recycled; solid residues obtained after separation are guided out, cooled and collected. The process not only realizes high recovery rate of titanium tetrachloride and enrichment and recovery of vanadium resources, but also greatly reduces energy consumption by virtue of internal heating and high efficiency characteristics of induction heating, and effectively solves the problems of high energy consumption, low efficiency and resource waste in treatment of the vanadium-containing slurry.

Description

Technical Field

[0001] This invention relates to the field of metallurgical environmental protection technology, specifically to a continuous treatment process and induction furnace system for refining vanadium-removing slurry from titanium tetrachloride. Background Technology

[0002] In the production of titanium dioxide or sponge titanium using the chloride process, titanium tetrachloride (TiCl4) is a key intermediate product. Vanadium impurities (mainly in the form of VOCl3) severely affect the color and performance of the final product, thus requiring thorough removal. Among various vanadium removal processes, organic vanadium removal has become the mainstream technology for refining crude titanium tetrachloride due to its large processing capacity and relatively low cost. The principle of this process is as follows: crude titanium tetrachloride is mixed with an organic reagent (such as mineral oil). The organic reagent decomposes at high temperature to produce reducing carbon, which reduces soluble VOCl3 to insoluble low-valent vanadium compounds (such as VO2, V2O3, etc.), thus forming a mixture composed of titanium tetrachloride, low-valent vanadium compounds, and carbonaceous solids produced by the decomposition of the organic reagent—this is the organic vanadium removal slurry.

[0003] The treatment of vanadium-containing sludge is a crucial step in achieving resource recovery and environmental protection. Currently, there are two main types of processes used in industry to treat vanadium-removing sludge containing organic matter: The first type is the spray condensation process. This process attempts to achieve solid-liquid separation by atomizing and condensing the slurry. However, this method requires extremely high equipment precision, has a complex process flow, and commonly suffers from the problem of easy clogging of the atomizing nozzles during operation, leading to unstable operation and making it difficult to meet the needs of continuous industrial production.

[0004] The second type is the slurry evaporation process. This process uses external heating devices such as pit furnaces to heat and evaporate the slurry in batches. Although this method achieves solid-liquid separation to some extent, it has inherent disadvantages such as high energy consumption, low thermal efficiency, and long processing cycle. At the same time, the poor fluidity of the slurry during evaporation can easily lead to scaling and deterioration of heat transfer inside the equipment.

[0005] Furthermore, the treatment method for vanadium-containing sludge generated from titanium tetrachloride removal, as disclosed in Chinese patent document CN107445421A, employs an integrated process of "sedimentation-evaporation-drying air circulation" within a single sedimentation-evaporation furnace. While this method simplifies the process to some extent and aims to remove chloride ions and carbon, it remains essentially an intermittent operation. The entire process relies on static sedimentation, staged stirring, and external heating, resulting in a ceiling on treatment efficiency and failing to fully utilize the physicochemical properties of the sludge itself. More importantly, this method focuses on waste stabilization, failing to efficiently recover valuable resources (especially vanadium) from the sludge.

[0006] Therefore, there is an urgent need in this field to develop a completely new processing technology that can fundamentally overcome the problems of easy equipment clogging, high energy consumption, low efficiency and insufficient resource recovery rate in existing technologies, and achieve efficient, continuous, energy-saving and resource-efficient treatment of vanadium removal slurry. Summary of the Invention

[0007] In view of this, the present invention proposes a continuous processing technology and induction furnace system for refining vanadium removal slurry with titanium tetrachloride, which can at least solve the problems of easy equipment clogging, high energy consumption, low efficiency and insufficient resource recovery rate in the prior art, and realize efficient, continuous, energy-saving and resource-efficient treatment of organic vanadium removal slurry.

[0008] The first aspect of this invention proposes a continuous processing technology for refining vanadium-removing slurry using titanium tetrachloride, comprising the following steps: continuously and uniformly introducing the refined vanadium-removing slurry into an induction furnace via a feed control device; utilizing the alternating magnetic field generated by the induction furnace to induce eddy current heating in the conductive components of the refined vanadium-removing slurry, thereby heating the slurry above the boiling point of the titanium tetrachloride solvent, achieving rapid solvent evaporation and solid-liquid separation; introducing the evaporated titanium tetrachloride vapor into a condensation system for condensation and recovery to obtain liquid titanium tetrachloride; and exporting the separated solid residue from the bottom of the induction furnace, collecting it after cooling.

[0009] In some embodiments, the organic matter refining vanadium removal slurry comprises the following components by mass fraction: 50% to 90% titanium tetrachloride; 5% to 30% carbonaceous solids produced by organic matter pyrolysis; 0.5% to 15% low-valent vanadium compounds, including one or more of VO2, V2O3, and VOCl2; and the balance being other metal chlorides other than titanium tetrachloride and VOCl2.

[0010] In some embodiments, the feed rate of the organic matter refining and vanadium removal slurry is controlled within the range of 1~2 t / h.

[0011] In some embodiments, the induction furnace is a medium-frequency induction furnace with an operating frequency range of 8~12kHz.

[0012] In some embodiments, the power range of the induction furnace is 120~200kWh.

[0013] In some embodiments, the heating temperature of the induction furnace is controlled at 480~650°C.

[0014] In some embodiments, the condensation temperature of titanium tetrachloride vapor is controlled between -10 and 50°C.

[0015] In some embodiments, the solid residue is cooled by indirect water cooling or air cooling, and the temperature after cooling is below 60°C.

[0016] A second aspect of this invention provides an induction furnace system for implementing the continuous processing technology described in any of the above embodiments, comprising: an induction furnace body, a feed control device, a condenser, a cooling and exhaust device, and a tailings collection device. The induction furnace body is made of a corrosion-resistant and high-temperature-resistant material. The feed control device is connected to the induction furnace body and is used to continuously and uniformly introduce organic refined vanadium-removing slurry into the induction furnace body. The condenser is connected to the steam outlet of the induction furnace body via a pipe and is used to condense and recover titanium tetrachloride vapor. The cooling and exhaust device is connected to the solids outlet of the induction furnace body and is used to cool and transport solid residues. The tailings collection device is used to collect the solid residues transported from the cooling and exhaust device.

[0017] In some embodiments, the feed control device includes a shielded pump and a flow meter. The cooling outlet device is a cooling conduit.

[0018] The beneficial effects of this invention are as follows: By continuously introducing vanadium-containing slurry into an induction furnace, this invention utilizes an alternating magnetic field to generate eddy currents within the conductive components (such as carbonaceous solids) of the slurry, achieving rapid flash evaporation and efficient solid-liquid separation of titanium tetrachloride solvent. This process not only achieves a high recovery rate of titanium tetrachloride (>98%) and the enrichment and recovery of vanadium resources, but also significantly reduces energy consumption due to the internal heating and high efficiency characteristics of induction heating. It avoids the problems of equipment scaling and pipeline blockage that are prone to occur in traditional external heating methods. The overall process is simple, highly continuous, and effectively solves the problems of high energy consumption, low efficiency, and resource waste in vanadium-containing slurry treatment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart of a continuous treatment process for refining vanadium-removing sludge with titanium tetrachloride according to an embodiment of the first aspect of the present invention; Figure 2 This is a schematic diagram of the structure of an induction furnace system provided in an embodiment of the second aspect of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Induction furnace body; 2. Feed control device; 3. Condenser; 4. Cooling and exhaust device; 5. Tailings collection device. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0023] A continuous treatment process for refining vanadium-removing sludge using titanium tetrachloride, as proposed in one embodiment of the first aspect of this invention, is as follows: Figure 1 As shown, the process includes the following steps: The organic vanadium-removing slurry is continuously and uniformly fed into an induction furnace via a feeding control device; the alternating magnetic field generated by the induction furnace causes eddy currents in the conductive components of the vanadium-removing slurry to generate heat, thereby heating the slurry above the boiling point of the titanium tetrachloride solvent, achieving rapid solvent evaporation and solid-liquid separation; the evaporated titanium tetrachloride vapor is introduced into a condensation system for condensation and recovery to obtain liquid titanium tetrachloride; the separated solid residue is discharged from the bottom of the induction furnace, cooled, and collected.

[0024] This invention achieves rapid flash evaporation and efficient solid-liquid separation of titanium tetrachloride solvent by continuously introducing vanadium-containing slurry into an induction furnace and using an alternating magnetic field to generate eddy currents within the conductive components (such as carbonaceous solids) of the slurry. This process not only achieves a high recovery rate of titanium tetrachloride (>98%) and the enrichment and recovery of vanadium resources, but also significantly reduces energy consumption due to the internal heating and high efficiency characteristics of induction heating. It avoids equipment scaling and pipeline blockage problems common in traditional external heating methods. The overall process is simple, continuous, and effectively solves the problems of high energy consumption, low efficiency, and resource waste in vanadium-containing slurry treatment.

[0025] In some embodiments, the vanadium-removing slurry from organic matter refining comprises the following components by mass fraction: 50%–90% titanium tetrachloride; 5%–30% carbonaceous solids produced by organic matter pyrolysis; 0.5%–15% low-valent vanadium compounds, including one or more of VO2, V2O3, and VOCl2; and the balance being other metal chlorides besides titanium tetrachloride and VOCl2. This composition ensures that the slurry contains a sufficient amount of conductive carbonaceous solids (5%–30%), enabling it to efficiently generate eddy current heating in the alternating magnetic field of the induction furnace, achieving rapid heating. Simultaneously, controlling the titanium tetrachloride content ensures processing efficiency while avoiding increased energy consumption due to excessive solvent. Furthermore, clearly defining the low-valent vanadium compound content directly relates to the recovery value of vanadium resources, ensuring that the final separated solid residue has significant economic recovery value.

[0026] In some embodiments, the feed rate of the organic vanadium-removing slurry is controlled within the range of 1 t / h to 2 t / h. Controlling the feed rate ensures that the slurry forms a stable and uniformly thick material layer in the induction furnace. This guarantees the full effect of the alternating magnetic field on the conductive components in the slurry to achieve efficient and uniform heating and evaporation, while avoiding incomplete evaporation, system pressure fluctuations, or excessive solid residue caused by excessively fast feeding. It also prevents decreased processing efficiency and waste of heat energy caused by excessively slow feeding, thus achieving the best balance between energy efficiency optimization, stable operation, and processing efficiency in continuous production.

[0027] In some embodiments, the induction furnace is a medium-frequency induction furnace with an operating frequency range of 8–12 kHz. The power range is 120–200 kWh, and the heating temperature is controlled between 480–650 °C. Setting the operating frequency of the induction furnace within the medium-frequency range of 8–12 kHz, combined with a power range of 120–200 kWh, allows the alternating magnetic field to effectively penetrate the slurry, ensuring sufficient eddy current heat generation in the conductive carbonaceous solids while preventing surface overheating and carbonization. Precisely controlling the heating temperature between 480–650 °C ensures rapid and complete evaporation and separation of the titanium tetrachloride solvent, while effectively preventing excessively high temperatures from accelerating equipment corrosion or causing adverse phase transitions in low-valent vanadium compounds. This achieves an optimal balance between energy efficiency, processing speed, and long-term stable operation of the equipment.

[0028] In some embodiments, the condensation temperature of titanium tetrachloride vapor is controlled between -10 and 50°C. Preferably, the condensation temperature is between 0°C and 30°C, which ensures that the vapor is quickly and fully condensed into a liquid state, achieving efficient recovery of titanium tetrachloride (recovery rate >98%). At the same time, this temperature range avoids ice or scale formation on the condenser surface, ensuring continuous and stable operation of the condensation process, and effectively preventing tail gas system blockage and environmental pollution caused by incomplete condensation.

[0029] In some embodiments, the solid residue is cooled by indirect water cooling or air cooling, and the temperature after cooling is below 60°C. Cooling the solid residue not only effectively reduces the temperature of the residue to eliminate the safety hazards of spontaneous combustion or burns, and facilitates subsequent safe transportation and storage, but also prevents the hydrolysis of harmful chlorides to form hydrochloric acid by avoiding direct contact with water. Thus, while ensuring operational safety, the recovery value of vanadium resources in the residue is preserved to the maximum extent.

[0030] The induction furnace system proposed in one embodiment of the second aspect of the present invention can be used to implement the continuous processing technology described in any of the above embodiments, such as... Figure 2As shown, the system includes: an induction furnace body 1, a feed control device 2, a condenser 3, a cooling and exhaust device 4, and a tailings collection device 5. The induction furnace body 1 is made of corrosion-resistant and high-temperature-resistant material, preferably graphite or graphite-lined material. The feed control device 2 is connected to the induction furnace body 1 and is used to continuously and uniformly introduce the organic refining and vanadium removal slurry into the induction furnace body 1. The condenser 3 is connected to the steam outlet of the induction furnace body 1 via a pipe and is used to condense and recover titanium tetrachloride vapor. The cooling and exhaust device 4 is connected to the solids outlet of the induction furnace body 1 and is used to cool and transport solid residues. The tailings collection device 5 is used to collect the solid residues transported from the cooling and exhaust device 4.

[0031] The working process of this induction furnace system is as follows: First, the organic vanadium-removing slurry is continuously and uniformly pumped into the induction furnace body 1 through the feed control device 2. After being powered on, the induction furnace generates a medium-frequency alternating magnetic field, which causes the conductive carbonaceous solids inside the slurry to generate strong eddy current heat, and the slurry temperature is rapidly raised to 480~650℃. The titanium tetrachloride solvent in it evaporates instantly, achieving efficient solid-liquid separation.

[0032] Next, the high-temperature titanium tetrachloride vapor generated by evaporation is discharged from the steam outlet at the top of the induction furnace and enters condenser 3 through a pipe. In the condenser, the vapor is cooled to -10~50℃ and re-condensed into high-purity liquid titanium tetrachloride, which is collected and reused in the production process, with a recovery rate of over 98%.

[0033] Finally, the remaining high-temperature solid slag after separation is discharged from the bottom of the induction furnace and immediately enters the cooling and discharge device 4. This device rapidly cools the incandescent slag to below 60°C through indirect water cooling or air cooling. The cooled solid slag (rich in vanadium resources) is safely transported to the tailings collection device 5 for centralized collection for subsequent resource utilization.

[0034] Throughout the process, all devices work together to achieve fully automated and continuous processing, from continuous mud feeding, induction heating evaporation, titanium tetrachloride condensation and recovery to solid residue cooling and collection.

[0035] In some embodiments, the feed control device 2 includes a shielded pump and a flow meter, ensuring absolute sealing and precise and stable flow of the corrosive slurry during transportation, thus guaranteeing the continuity and controllability of the process from the source. The cooling outlet device 4 is a cooling conduit that provides an efficient and sealed heat dissipation path for the high-temperature solid residue, achieving rapid cooling while completely avoiding the risk of harmful substances escaping or hydrolysis caused by direct contact between the residue and air or cooling water.

[0036] The specific technical solutions of the present invention are further illustrated below with reference to several embodiments. It should be noted that the following embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way.

[0037] Example 1 A continuous treatment process for refining vanadium-removing sludge from organic matter, using, for example Figure 2 The induction furnace system shown includes an induction furnace body 1, a cooling outlet device 4 (specifically a cooling conduit), a condenser 3, and a tailings collection device 5 (specifically a tailings tray). The steps are as follows: The vanadium-removing slurry, which is made from organic matter with a solid content of 15%, is continuously and uniformly fed into a medium-frequency induction furnace with a power of about 150 kWh and a frequency of about 10 kHz at a rate of about 1.5 t / h through a feed control device consisting of a shielded pump and a flow meter.

[0038] The alternating magnetic field generated by the induction furnace induces eddy currents in the carbonaceous solids in the slurry, rapidly heating the slurry to approximately 550°C (the range can be adjusted within 500~600°C). Under these conditions, the titanium tetrachloride solvent is rapidly vaporized, achieving solid-liquid separation.

[0039] The vaporized titanium tetrachloride vapor is discharged from the top of the furnace and enters the condenser where it is condensed to about 40°C (temperature <50°C) and recovered as liquid titanium tetrachloride.

[0040] The high-temperature solid residue of about 500°C obtained after separation is discharged from the bottom of the induction furnace. After being indirectly cooled to about 30°C through a cooling pipe, it enters the tail slag pan for collection and is used for subsequent vanadium resource recovery.

[0041] Example 2 Using the same system as in Example 1, an organic vanadium-removing slurry with a solids content of 25% was processed. This slurry had a higher carbonaceous solids content and better electrical conductivity.

[0042] The slurry is continuously and uniformly fed into a medium-frequency induction furnace with a power of about 180 kWh and a frequency of about 8 kHz at a rate of about 1.0 t / h via the feed control device 2.

[0043] The alternating magnetic field generated by the induction furnace induces eddy currents in the carbonaceous solids in the slurry, rapidly heating the slurry to approximately 600°C. At this temperature, titanium tetrachloride is rapidly vaporized, achieving solid-liquid separation.

[0044] Titanium tetrachloride vapor is recovered after condensation to approximately 20°C. Solid residue is collected after being cooled to approximately 50°C via a cooling conduit. This example demonstrates that even for slurries with high solid content and poor fluidity, this process can still achieve efficient and stable continuous processing by appropriately adjusting the feed rate and power.

[0045] Example 3 Using the same system as in Example 1, vanadium-removing slurry with an organic content of 10% was processed.

[0046] The slurry is fed into a medium-frequency induction furnace with a power of about 120 kWh and a frequency of about 12 kHz at a relatively high rate of about 2.0 t / h via a feed control device.

[0047] Because of the low solid content of the mud, the required enthalpy of evaporation is reduced, and the system can achieve rapid evaporation of titanium tetrachloride at a relatively low temperature of about 480°C.

[0048] Titanium tetrachloride vapor is condensed to approximately 0°C and then recovered to further improve the recovery rate. Solid residue is collected after cooling. This combination of parameters significantly reduces energy consumption per unit of material while maintaining high processing efficiency, demonstrating the process's potential for energy efficiency optimization.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A continuous treatment process for refining vanadium-removing sludge using titanium tetrachloride, characterized in that, Includes the following steps: The refined vanadium-removing slurry made from organic matter is continuously and evenly introduced into the induction furnace; The alternating magnetic field generated by the induction furnace causes the conductive components in the organic vanadium-removing slurry to generate eddy currents and heat up, thereby heating the organic vanadium-removing slurry to above the boiling point of titanium tetrachloride solvent, achieving rapid solvent evaporation and solid-liquid separation. The evaporated titanium tetrachloride vapor is condensed and recovered to obtain liquid titanium tetrachloride; The separated solid residue is extracted, cooled, and then collected.

2. The continuous processing technology according to claim 1, characterized in that, The organic-refined vanadium-removing slurry comprises the following components by mass fraction: 50%~90% titanium tetrachloride; 5% to 30% of carbonaceous solids are produced by the cracking of organic matter; 0.5% to 15% of low-valent vanadium compounds, wherein the low-valent vanadium compounds include one or more of VO2, V2O3, and VOCl2; The balance consists of other metal chlorides besides titanium tetrachloride and VOCl2.

3. The continuous processing technology according to claim 1, characterized in that, The feed rate of the organic vanadium-removing slurry is controlled within the range of 1~2 t / h.

4. The continuous processing technology according to claim 1, characterized in that, The induction furnace is a medium-frequency induction furnace with a working frequency range of 8~12kHz.

5. The continuous processing technology according to claim 1, characterized in that, The power range of the induction furnace is 120~200kWh.

6. The continuous processing technology according to claim 1, characterized in that, The heating temperature of the induction furnace is controlled at 480~650℃.

7. The continuous processing technology according to claim 1, characterized in that, The condensation temperature of the titanium tetrachloride vapor is controlled between -10 and 50°C.

8. The continuous processing technology according to claim 1, characterized in that, The solid residue is cooled by indirect water cooling or air cooling, and the temperature after cooling is below 60°C.

9. An induction furnace system, characterized in that, For implementing the continuous processing technology according to any one of claims 1-8, comprising: Induction furnace body (1); The feeding control device (2) is connected to the induction furnace body (1) and is used to continuously and uniformly introduce the organic refined vanadium removal slurry into the induction furnace body (1); The condenser (3) is connected to the steam outlet of the induction furnace body (1) via a pipe and is used to condense and recover titanium tetrachloride vapor; A cooling outlet device (4) is connected to the solid outlet of the induction furnace body (1) for cooling and conveying solid residue; Tailings collection device (5) is used to collect solid residues transported from the cooling discharge device (4).

10. The induction furnace system according to claim 9, characterized in that, The feed control device (2) includes a shielded pump and a flow meter; and / or, the cooling outlet device (4) is a cooling conduit.

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