Titanium tetrachloride off-gas condensing device

Abstract

This utility model discloses a titanium tetrachloride flue gas condensation device, comprising: a condenser shell, with a titanium tetrachloride flue gas inlet on the side, a tail gas outlet at the top, and a crude titanium tetrachloride outlet at the bottom; a partitioned heat exchange condensate component, disposed within the condenser shell, which condenses the titanium tetrachloride flue gas into a liquid state through indirect heat exchange; a product tank, connected to the crude titanium tetrachloride outlet, for collecting the condensed liquid titanium tetrachloride; a cooling medium supply system, for supplying a cooling medium to the partitioned heat exchange condensate component, through which the cooling medium transfers heat from the titanium tetrachloride flue gas to itself; and a regulating device for adjusting the cooling medium supply parameters. This design avoids using liquid titanium tetrachloride as the cooling medium and eliminates the problem of reduced titanium tetrachloride production caused by the recycling of titanium tetrachloride in spray systems.

Description

Technical Field

[0001] This disclosure relates to the field of titanium tetrachloride production technology. The embodiments of this disclosure relate to a titanium tetrachloride crude production system, a titanium tetrachloride refining system, a titanium tetrachloride flue gas condensation device for a titanium tetrachloride crude production system, an integrated evaporation, distillation and condensation device for a titanium tetrachloride refining system, and a low-boiling-point impurity recovery system for a titanium tetrachloride refining system. Background Technology

[0002] Currently, the market demand for titanium tetrachloride is experiencing rapid growth. This is mainly due to increased production of sponge titanium (which can almost exclusively be prepared through the reduction of titanium tetrachloride, i.e., the Kroll process) and the promotion of the chloride process in titanium dioxide production. While few titanium dioxide manufacturers currently use the chloride process, it is gradually replacing the traditional sulfate process as the development trend in the titanium dioxide industry due to its numerous advantages, including efficient resource utilization, minimal generation of solid and hazardous waste, minimal consumption of sulfur ore resources, and superior product quality.

[0003] Existing titanium tetrachloride production systems include a crude titanium tetrachloride production section and a refining titanium tetrachloride production section. The crude titanium tetrachloride production section uses equipment such as chlorination furnaces, dust collectors, and washing towers to chlorinate and initially remove impurities from titanium-containing raw materials, obtaining crude titanium tetrachloride. The refining titanium tetrachloride production section mainly uses the mineral oil method to further remove impurities through mixing, evaporation, distillation, and condensation processes, ultimately producing refined titanium tetrachloride. However, existing titanium tetrachloride production technology remains relatively rudimentary, resulting in insufficient resource utilization, high energy consumption, and significant environmental problems. Utility Model Content

[0004] The following technical solutions disclosed herein will make several improvements to the crude titanium tetrachloride section and the refined titanium tetrachloride section, respectively.

[0005] In a first aspect, a crude titanium tetrachloride system includes: a dust removal unit for efficiently collecting dust from titanium tetrachloride flue gas discharged from a chlorination furnace; and a cooling unit for cooling the titanium tetrachloride flue gas after the efficient dust collection treatment, collecting crude titanium tetrachloride product, and simultaneously discharging tail gas at a temperature ≤70°C; wherein the dust removal efficiency of the dust removal unit is such that the solid mass percentage content in the crude titanium tetrachloride product collected by the cooling unit is ≤0.1%; and, in the entire titanium tetrachloride flue gas flow path from the chlorination furnace to the cooling unit, the titanium tetrachloride flue gas does not pass through any other cooling equipment except for natural cooling.

[0006] Secondly, a crude titanium tetrachloride system includes: a dust removal unit for collecting dust from titanium tetrachloride flue gas discharged from a chlorination furnace; a cooling unit for cooling the titanium tetrachloride flue gas after dust collection and collecting crude titanium tetrachloride while simultaneously discharging tail gas at a temperature ≤70°C; and a post-cooling membrane filtration unit for performing liquid-solid separation membrane filtration on the crude titanium tetrachloride to obtain a crude titanium tetrachloride filtrate; wherein the combined dust removal efficiency of the dust removal unit and the filtration efficiency of the post-cooling membrane filtration unit ensures that the solid mass percentage content in the crude titanium tetrachloride filtrate is ≤0.1%; and, in the entire titanium tetrachloride flue gas flow path from the chlorination furnace to the cooling unit, the titanium tetrachloride flue gas does not pass through any other cooling equipment except for natural cooling.

[0007] Thirdly, a titanium tetrachloride flue gas condensation device includes: a condenser shell, wherein the condenser shell has a titanium tetrachloride flue gas inlet on its side, a tail gas outlet at its top, and a titanium tetrachloride crude product outlet at its bottom; a partitioned heat exchange condensate component, wherein the partitioned heat exchange condensate component is disposed in the condenser shell and condenses the titanium tetrachloride flue gas into a liquid state through indirect heat exchange; a product tank, wherein the product tank is connected to the titanium tetrachloride crude product outlet and is used to collect the condensed titanium tetrachloride; a cooling medium supply system, wherein the cooling medium supply system is used to supply a cooling medium to the partitioned heat exchange condensate component, wherein the cooling medium transfers heat from the titanium tetrachloride flue gas to the cooling medium through the partitioned heat exchange condensate component; and an adjustment device, wherein the adjustment device is connected to the cooling medium supply system and is used to adjust the cooling medium supply parameters to control the condensation effect on the titanium tetrachloride flue gas.

[0008] Fourthly, a titanium tetrachloride refining system includes: a refining unit that receives crude titanium tetrachloride from a titanium tetrachloride crude refining system and purifies the crude titanium tetrachloride into refined titanium tetrachloride; and a pre-filtration membrane unit for the refining unit, which performs liquid-solid separation membrane filtration on the crude titanium tetrachloride to obtain a crude titanium tetrachloride filtrate, and then inputs the crude titanium tetrachloride filtrate into the refining unit; the filtration efficiency of the pre-filtration membrane unit is such that the solid mass percentage content in the crude titanium tetrachloride filtrate is ≤0.1%.

[0009] Fifthly, a titanium tetrachloride refining system includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes: a mixer for mixing crude titanium tetrachloride with mineral oil to obtain a mixture; an evaporator for evaporating the mixture to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and to obtain a clear evaporator and an evaporation residue; and a distillation apparatus for distilling the clear evaporator to obtain a distilled gas and a distillation residue, wherein the distillation residue contains... The distillation process includes: a high-boiling-point impurity relative to the boiling point of titanium tetrachloride; a condensation device for condensing the distilled gas to obtain refined titanium tetrachloride; and a solid-liquid separation unit for separating the evaporation residue and the distillation residue to obtain a clear liquid phase and a residue-liquid phase; and a post-solid-liquid membrane filtration unit for performing liquid-solid separation membrane filtration on the clear liquid phase and returning the filtrate after liquid-solid separation membrane filtration to the distillation device for distillation.

[0010] Sixthly, a titanium tetrachloride refining system includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes: a mixer for mixing crude titanium tetrachloride with mineral oil to obtain a mixture; an evaporator for evaporating the mixture to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and to obtain a clear evaporator and an evaporation residue; and a distillation apparatus for distilling the clear evaporator to obtain a distilled gas and a distillation residue, wherein the distillation residue contains... The product includes: a high-boiling-point impurity relative to the boiling point of titanium tetrachloride; a condensation device for condensing the distilled gas to obtain refined titanium tetrachloride; a solid-liquid separation unit for separating the evaporation residue and the distillation residue to obtain a clear liquid phase and a residue-liquid phase; and a sealed baking device for sealing and baking the residue-liquid phase to obtain titanium tetrachloride vapor and high-vanadium dry residue, wherein the titanium tetrachloride vapor and the distilled gas enter the condensation device for condensation.

[0011] In a seventh aspect, an integrated evaporation, distillation, and condensation apparatus for refining titanium tetrachloride includes a vertical outer cylinder and a vertical inner cylinder housed within the outer cylinder. An outer chamber is formed between the outer and inner cylinders, and an inner chamber is formed within the inner cylinder. A condensation chamber is formed at the top of the outer chamber, an evaporation chamber at the bottom, a cooling chamber at the top of the inner chamber, and a distillation chamber at the bottom. The lower part of the condensation chamber is separated from the upper part of the evaporation chamber by a partition. The lower part of the cooling chamber is connected to the upper part of the distillation chamber. The upper opening of the cooling chamber is located within the condensation chamber. An evaporation heating device is provided at the evaporation chamber, and a distillation heating device is provided at the distillation chamber. The condensation chamber has a refined titanium tetrachloride product outlet, and the evaporation chamber has a mixed liquid inlet, a low-boiling-point impurity outlet, and an evaporation residue outlet. An evaporation clear liquid guide channel is provided between the evaporation chamber and the distillation chamber. The distillation chamber has a distillation residue outlet; the evaporation chamber is used to evaporate the mixture formed by crude titanium tetrachloride and mineral oil that enters the evaporation chamber through the mixed liquid inlet, removing low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtaining a clear evaporator and an evaporation residue. The low-boiling-point impurities are discharged from the low-boiling-point impurity outlet, the clear evaporator enters the distillation chamber through the clear evaporator guide channel, and the evaporation residue is discharged from the evaporation residue outlet; the distillation chamber is used to distill the clear evaporator to obtain distilled gas and distillation residue. The distillation residue contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride, and the distillation residue is discharged from the distillation residue outlet; the distilled gas rises and enters the cooling chamber for cooling before entering the condensation chamber; the condensation chamber is used to condense the cooled distilled gas to obtain refined titanium tetrachloride product, which is discharged from the refined titanium tetrachloride product outlet.

[0012] Eighthly, a titanium tetrachloride refining system includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes a mixer for mixing crude titanium tetrachloride with mineral oil to obtain a mixture. The mineral oil refining unit also includes the integrated evaporation, distillation and condensation apparatus for titanium tetrachloride refining described in the seventh aspect above.

[0013] Ninthly, an integrated evaporation-distillation-condensation apparatus for refining titanium tetrachloride includes a vertical cylindrical body and a condensation container communicating with the upper part of the vertical cylindrical body; the lower part of the vertical cylindrical body forms an integrated evaporation-distillation chamber, the upper part of the vertical cylindrical body forms a cooling chamber, the lower part of the cooling chamber is communicating with the upper part of the integrated evaporation-distillation chamber, a condensate chamber is formed in the condensation container, the upper opening of the cooling chamber is communicating with the condensate chamber, and the integrated evaporation-distillation chamber is provided with alternating evaporation heating devices and distillation heating devices; the condensate chamber has a refined titanium tetrachloride product outlet, and the integrated evaporation-distillation chamber has a mixed liquid inlet, a low-boiling-point impurity outlet, an evaporation residue outlet, and a distillation residue outlet; when the integrated evaporation-distillation chamber is used as an evaporation chamber, it is used to process the crude titanium tetrachloride and mineral oil that enter the evaporation chamber through the mixed liquid inlet. The mixture is evaporated to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, yielding a clear evaporator and an evaporation residue. The low-boiling-point impurities are discharged from the low-boiling-point impurity outlet, while the clear evaporator remains stored in the integrated evaporation-distillation chamber. The evaporation residue is discharged from the evaporation residue outlet. When the integrated evaporation-distillation chamber is used as a distillation chamber, it is used to distill the clear evaporator to obtain distilled gas and distillation residue. The distillation residue contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride, and is discharged from the distillation residue outlet. The distilled gas rises and enters the cooling chamber for cooling before entering the condensation chamber. The condensation chamber is used to condense the cooled distilled gas to obtain refined titanium tetrachloride product, which is discharged from the refined titanium tetrachloride product outlet.

[0014] Tenthly, a titanium tetrachloride refining system includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes a mixer for mixing crude titanium tetrachloride with mineral oil to obtain a mixture. The mineral oil refining unit also includes the integrated evaporation, distillation, and condensation apparatus for titanium tetrachloride refining described in the ninth aspect above.

[0015] Eleventhly, a titanium tetrachloride refining system includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes: a mixer for mixing crude titanium tetrachloride with mineral oil to obtain a mixture; an evaporator for evaporating the mixture to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtaining a clear evaporator and a slag evaporator; a distillation apparatus for distilling the clear evaporator to obtain a distilled gas and a slag evaporator, wherein the slag evaporator contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride; and a condensation apparatus for condensing the distilled gas to obtain refined titanium tetrachloride product. The mineral oil refining unit includes a low-boiling-point impurity condenser for recovering low-boiling-point impurities that escape during the evaporation process of the evaporator and condensing the low-boiling-point impurities into a liquid mixture rich in silicon tetrachloride.

[0016] Twelfth aspect, a low-boiling-point impurity recovery system for use in the titanium tetrachloride refining system of the eleventh aspect; comprising: a low-boiling-point impurity condenser for recovering low-boiling-point impurities escaping during the evaporation process of the evaporator and condensing the low-boiling-point impurities into a liquid mixture rich in silicon tetrachloride.

[0017] The above-mentioned technical solution improves the crude and refined titanium tetrachloride processes, thereby increasing resource utilization, reducing production energy consumption, and / or reducing environmental pollution.

[0018] The present disclosure will now be further described in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present disclosure will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are used to aid in understanding this disclosure. The contents provided in the drawings and their related descriptions in this specification may be used to interpret this disclosure, but do not constitute an undue limitation of this disclosure.

[0020] Figure 1 This is a schematic diagram of an existing titanium tetrachloride production system.

[0021] Figure 2 This is a schematic diagram of the crude titanium tetrachloride system according to Embodiment 1 of this disclosure.

[0022] Figure 3 This is a schematic diagram of the titanium tetrachloride crude preparation system of Embodiment 2 of this disclosure.

[0023] Figure 4 for Figure 2The diagram shows a titanium tetrachloride flue gas condensation device in the titanium tetrachloride crude system.

[0024] Figure 5 for Figure 3 The diagram shows a scrubbing tower in the titanium tetrachloride crude processing system.

[0025] Figure 6 This is a schematic diagram of the titanium tetrachloride refining system according to Embodiment 1 of this disclosure.

[0026] Figure 7 This is a schematic diagram of the titanium tetrachloride refining system of Embodiment 2 of this disclosure.

[0027] Figure 8 This is a schematic diagram of the titanium tetrachloride refining system of Embodiment 3 of this disclosure.

[0028] Figure 9 This is a schematic diagram of an integrated evaporation, distillation and condensation apparatus for the purification of titanium tetrachloride in Example 1.

[0029] Figure 10 This is a schematic diagram of an integrated evaporation, distillation and condensation apparatus for the purification of titanium tetrachloride in Example 2.

[0030] Figure 11 This is a schematic diagram of the integrated evaporation, distillation and condensation apparatus used for the purification of titanium tetrachloride in Example 3.

[0031] Figure 12 This is a schematic diagram of the titanium tetrachloride refining system of Embodiment 7 of this disclosure. Detailed Implementation

[0032] The present disclosure will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present disclosure based on these descriptions. Before describing the present disclosure in conjunction with the accompanying drawings, it should be particularly noted that:

[0033] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0034] The embodiments described below are generally only some embodiments and not all embodiments. All other embodiments obtained by those skilled in the art based on these embodiments without creative effort should fall within the scope of patent protection.

[0035] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0036] Figure 1 This is a schematic diagram of an existing titanium tetrachloride production system. Figure 1 As shown, the existing titanium tetrachloride production is divided into two main sections: a titanium tetrachloride crude processing section and a titanium tetrachloride refining section. In the titanium tetrachloride crude processing section, titanium-containing raw materials (high-titanium slag or rich titanium ore) react with carbon and chlorine to form titanium tetrachloride. The titanium tetrachloride, in gaseous form, exits from the chlorination furnace 1 along with the high-temperature furnace gas (commonly referred to as titanium tetrachloride flue gas). After a primary cooling spray (using room-temperature titanium tetrachloride liquid from a subsequent thickener), the temperature of the titanium tetrachloride flue gas is reduced to 200℃-250℃. After dust removal (gravity dust collector 2 and cyclone dust collector 3), it enters the scrubbing tower 4. The scrubbing tower 4 uses low-temperature titanium tetrachloride liquid for cold scrubbing (a secondary cooling spray, using cooled room-temperature titanium tetrachloride liquid), turning the gaseous titanium tetrachloride into a liquid state, which is then recovered along with the dust to the slag-liquid tank 5. After overflowing from slag tank 5 to thickener 6 for concentration, the slag then undergoes prolonged sedimentation in multiple settling tanks 7 (sedimentation time greater than 48 hours). The supernatant is crude titanium tetrachloride (currently, the solid content in crude titanium tetrachloride is approximately 1%-2%). Crude titanium tetrachloride also contains impurities with melting and boiling points similar to titanium tetrachloride (such as chlorides of vanadium, aluminum, iron, and silicon), so it needs to be transported to the titanium tetrachloride refining section for further impurity removal. The refined liquid after impurity removal is the refined titanium tetrachloride product. The settled slag from slag tank 5, thickener 6, and settling tank 7 is returned to the chlorination furnace for treatment. Large volumes of returned slag can affect the thermal balance of the chlorination furnace. Settled slag that cannot be returned to the furnace will be neutralized in water with an alkaline substance.

[0037] like Figure 1As shown, the refining process for titanium tetrachloride typically employs a mineral oil method. Currently, the mineral oil refining process is as follows: First, crude titanium tetrachloride enters mixer 8, which mixes the crude titanium tetrachloride with mineral oil to obtain a mixture. The mixture then enters evaporator 9, which evaporates the mixture (heating temperature is typically 120℃-140℃) to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride (these impurities escape in gaseous form), yielding a clear evaporator (titanium tetrachloride liquid with low-boiling-point impurities removed) and an evaporation residue. During the evaporation process, the mineral oil dispersed in the titanium tetrachloride carbonizes and reacts with chlorides (such as vanadium oxychloride) with boiling points close to those of titanium tetrachloride, generating high-melting-boiling-point substances (such as vanadium trichloride and vanadium tetrachloride) that settle to the bottom of the evaporator. These, along with unreacted substances carried in by the mineral oil and solid particles carried in by the crude titanium tetrachloride, form the evaporation residue. The evaporation residue is viscous. After initial dehydration using methods such as sedimentation or centrifuge 10, the liquid phase is returned to evaporator 9 for further evaporation, while a portion of the concentrated liquid phase is returned to chlorination furnace 1, and the remaining portion is neutralized in water with an alkaline substance. Subsequently, the clear evaporation liquid enters distillation unit 11 (generally a rectification column). Distillation unit 11 is used to distill the clear evaporation liquid (the heating temperature is generally controlled above 135℃), yielding distilled gas (titanium tetrachloride vapor) and distillation residue. The distillation residue contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride. After initial dehydration using methods such as sedimentation or centrifuge 12, the liquid phase is returned to distillation unit 11 for further distillation, while a portion of the concentrated liquid phase is returned to chlorination furnace 1, and the remaining portion is neutralized in water with an alkaline substance. Finally, the distilled gas enters condensation unit 13, where it is condensed to obtain refined titanium tetrachloride product.

[0038] However, the aforementioned titanium tetrachloride production system has significant problems in both the crude titanium tetrachloride processing section and the refining section. In the crude titanium tetrachloride processing section, the main problems are: low solid-liquid separation efficiency; excessively long sedimentation time in sedimentation tank 7, with almost no effect on fine particles, resulting in a solid content of 1%-2% in the crude titanium tetrachloride product; insufficient utilization of titanium resources; the sludge in slag tank 5, thickener 6, and sedimentation tank 7 contains a large amount of titanium tetrachloride, which, if returned to chlorination furnace 1, would affect the thermal balance of the chlorination furnace, while neutralization with alkaline substances would waste titanium tetrachloride resources; excessive energy consumption; the large amount of returned sludge disrupts the original reaction thermal balance within the chlorination furnace, requiring increased coke consumption, while primary and secondary cooling sprays consume a large amount of energy; and severe environmental pollution; the titanium tetrachloride-containing sludge that cannot be returned to the furnace needs to be neutralized with alkaline substances, generating large amounts of harmful wastewater and gas emissions. The main problems in the titanium tetrachloride refining section are as follows: unreasonable material circulation; low efficiency in the treatment of slag and liquid in evaporator 9 and distillation unit 11, resulting in a large amount of energy waste due to return processing; improper slag and liquid treatment; the evaporation and distillation slag and liquid contain a large amount of titanium tetrachloride, and the initial dehydration effect of centrifuges 10 and 12 is limited, resulting in a high liquid content in the concentrated liquid phase returned to chlorination furnace 1, affecting the thermal balance of the chlorination furnace; accumulation of impurities; the failure to effectively open the system to discharge impurities such as vanadium chloride, leading to a gradual deterioration of process conditions; waste of valuable resources; the failure to effectively recover and utilize valuable impurities such as vanadium generated during the refining process; and significant environmental pollution, as some concentrated liquid phase needs to be neutralized in water with alkaline substances, causing secondary pollution.

[0039] Figure 2 This is a schematic diagram of a titanium tetrachloride crude preparation system according to Embodiment 1 of this disclosure. It is used to improve the titanium tetrachloride crude preparation section in an existing titanium tetrachloride production system. Figure 4 for Figure 2 The diagram shows a schematic of the titanium tetrachloride flue gas condensation device in the titanium tetrachloride crude titanium production system. Figure 2 , Figure 4 As shown, the titanium tetrachloride crude product system of Embodiment 1 of this disclosure includes: a dust removal unit for efficiently collecting dust from the titanium tetrachloride flue gas discharged from the chlorination furnace 1; and a cooling unit for cooling the titanium tetrachloride flue gas after efficient dust collection, and collecting the titanium tetrachloride crude product while discharging tail gas with a temperature ≤70°C; wherein, the dust removal efficiency of the dust removal unit is such that the solid mass percentage content in the titanium tetrachloride crude product collected by the cooling unit is ≤0.1%; and, in the entire titanium tetrachloride flue gas flow path from the chlorination furnace 1 to the cooling unit, the titanium tetrachloride flue gas does not pass through any other cooling equipment except for natural cooling.

[0040] The titanium tetrachloride crude preparation system of Embodiment 1 of this disclosure can firstly reduce the solid mass percentage content in the crude titanium tetrachloride to ≤0.1%, significantly reducing solid impurities and improving the purity of the crude titanium tetrachloride. This significantly reduces the processing burden of the subsequent titanium tetrachloride refining section, reduces the amount of returned slag liquid and resource waste, and improves resource utilization and production efficiency. Secondly, in the past, due to the low dust removal efficiency of the dust removal unit and the use of a scrubbing tower in the cooling unit, a large amount of energy must be consumed to reduce the tail gas temperature to ≤70°C to fully recover titanium tetrachloride. (When the dust content in the titanium tetrachloride flue gas is high, a large number of dust particles will hinder the direct contact between the titanium tetrachloride flue gas and the scrubbing liquid, and the dust particles may reduce the atomization effect of the scrubbing liquid, thereby weakening the gas-liquid heat exchange and condensation efficiency.) The titanium tetrachloride crude product system of Embodiment 1 of this disclosure improves the dust removal efficiency of the dust removal unit, ensuring that the solid content in the crude titanium tetrachloride collected by the cooling unit is ≤0.1% by mass. This effectively reduces the interference of solid impurities during the cooling process, making it easier to reduce the exhaust gas temperature to ≤70°C without significantly increasing cooling energy consumption, thus avoiding the high energy consumption problem of the cooling unit. Finally, because it can efficiently cool down and ensure the full recovery of titanium tetrachloride in the exhaust gas, the original primary cooling spray is eliminated, thereby simplifying the process flow, further reducing energy consumption, and significantly improving the economy and environmental friendliness of the titanium tetrachloride crude product system.

[0041] Specifically, the dust removal unit includes at least two stages of dust collectors, and at least the latter stage of the dust collector uses a precision flue gas filter dust collector 14. The filter element of the precision flue gas filter dust collector 14 can withstand the temperature of the titanium tetrachloride flue gas to be filtered, is resistant to chlorine corrosion, and can achieve a dust content of ≤5mg / Nm³ in the filtered titanium tetrachloride flue gas. 3 Filtration efficiency.

[0042] The filter element of the flue gas precision filter dust collector 14 can not only withstand the high temperature characteristics of titanium tetrachloride flue gas, but also has excellent resistance to chlorine corrosion, ensuring that the flue gas precision filter dust collector 14 can operate stably for a long time in a highly corrosive environment.

[0043] Preferably, the filter element of the flue gas precision filter dust collector 14 is a sintered metal filter element with Hastelloy C-276 as the main material. Hastelloy C-276 is a nickel-based corrosion-resistant alloy, mainly composed of nickel, molybdenum, chromium, iron, and other elements, possessing excellent corrosion resistance and mechanical properties. Its high nickel and molybdenum content endows it with excellent corrosion resistance to strong oxidizing and reducing media (such as wet chlorine gas, chloride solutions, etc.), the addition of chromium enhances its oxidation resistance, and the extremely low carbon content effectively reduces the sensitivity to intergranular corrosion. In addition, Hastelloy C-276 has good high-temperature stability and mechanical strength, and is widely used in the manufacture of equipment in high-corrosion and high-temperature environments, such as chemical plants and flue gas filter elements, enabling long-term stable operation and significantly extending the service life of equipment. From a structural performance perspective, the sintered metal filter element has a precise pore structure, which not only achieves high-efficiency filtration but also ensures the mechanical strength and durability of the filter element, effectively reducing operating and maintenance costs.

[0044] In addition, the applicant may perform the following surface treatment steps on the aforementioned sintered metal filter element: Step 1: Electrochemical polishing is performed on the surface of the main material to form an initial passivation layer rich in chromium and molybdenum with a surface roughness Ra of 0.2 μm-0.3 μm; Step 2: Anodizing is performed on the surface of the initial passivation layer to form an oxide layer with a thickness of 50 nm-80 nm, mainly composed of Cr2O3, MoO3, and NiO; Step 3: Passivating agent treatment is performed on the surface of the oxide layer to form a stable passivation layer rich in chromium and molybdenum, wherein the passivating agent comprises highly oxidized chromium salts, molybdates, and hydrofluoric acid.

[0045] The first step, electrochemical polishing, forms an initial passivation layer rich in chromium and molybdenum on the surface of the base material, while controlling the surface roughness Ra to 0.2μm-0.3μm. This significantly improves the material's corrosion resistance and surface finish, providing a good foundation for subsequent treatments. The second step, anodic oxidation, further forms an oxide layer with a thickness of 50nm-80nm on the surface of the initial passivation layer, mainly composed of Cr2O3, MoO3, and NiO. This dense oxide layer greatly enhances the material's resistance to chlorine corrosion and its high-temperature stability. The third step, through passivation agent treatment, forms a stable passivation layer rich in chromium and molybdenum on the oxide layer surface, further improving the filter element's corrosion resistance and long-term performance, especially effectively extending its service life in highly corrosive environments. The combined effect of this surface treatment process ensures the high efficiency, reliability, and durability of the sintered metal filter element when filtering titanium tetrachloride flue gas, providing a crucial guarantee for the stable operation of the titanium tetrachloride coarsening system.

[0046] At least two-stage dust collectors typically include a gravity dust collector 2, a cyclone dust collector 3, and a flue gas precision filter dust collector 14, which are connected sequentially along the flow path of titanium tetrachloride flue gas.

[0047] Alternatively, at least two dust collectors may include a gravity dust collector 2 and a precision flue gas filter dust collector 14 connected sequentially along the flow path of titanium tetrachloride flue gas.

[0048] Alternatively, at least two-stage dust collectors may include a cyclone dust collector 3 and a flue gas precision filter dust collector 14 connected sequentially along the flow path of titanium tetrachloride flue gas.

[0049] Furthermore, the cooling unit also employs a titanium tetrachloride flue gas condensation device 15. For example... Figure 4 As shown, the titanium tetrachloride flue gas condensation device 15 includes: a condenser shell, with a titanium tetrachloride flue gas inlet 151 on the side, a tail gas outlet 152 at the top, and a titanium tetrachloride crude product outlet at the bottom; a partition wall heat exchange condensate component 153, which is disposed in the condenser shell and condenses the titanium tetrachloride flue gas into a liquid state through indirect heat exchange; and a product tank 154, which is connected to the titanium tetrachloride crude product outlet and is used to collect the condensed titanium tetrachloride (the product tank 154 is provided with a drain port 158 ​​for discharging the titanium tetrachloride crude product). A cooling medium supply system 155 is used to supply cooling medium to the indirect heat exchange condensate component 153 (the cooling medium supply system 155 is connected to the indirect heat exchange condensate component 153 through a cooling medium inlet pipe 156 and a cooling medium outlet pipe 156 to realize the flow of cooling medium). The cooling medium transfers the heat in the titanium tetrachloride flue gas to the cooling medium through the indirect heat exchange condensate component 153. An adjustment device is connected to the cooling medium supply system 155 and is used to adjust the cooling medium supply parameters to control the condensation effect on the titanium tetrachloride flue gas.

[0050] The titanium tetrachloride flue gas condensation device 15 employs an indirect heat exchange condensate component 153 to achieve indirect heat exchange. This allows the titanium tetrachloride flue gas, after efficient treatment by the precision flue gas filter dust collector 14, to condense into liquid titanium tetrachloride through heat transfer to the cooling medium, which is then collected as crude titanium tetrachloride by the product tank 154. The most significant advantage of this design is that it completely replaces the traditional primary and secondary cooling spray methods, avoiding the use of liquid titanium tetrachloride as a cooling medium and eliminating the problem of reduced titanium tetrachloride production caused by the recycling of titanium tetrachloride in the spray system. Combined with a front-end high-efficiency dust removal unit (solid mass percentage content ≤0.1%), the condensation efficiency is significantly improved. This ensures that the exhaust gas temperature is ≤70℃ for full recovery of titanium tetrachloride, significantly simplifies the process flow, reduces energy consumption, and fundamentally solves the key problems of low solid-liquid separation efficiency, insufficient utilization of titanium resources, and excessive energy consumption in the traditional crude processing section.

[0051] The cooling medium can be water, brine, or refrigerant. Furthermore, the refrigerant is selected from at least one of ammonia (R717), R22, R32, R134a, or R290, conforming to "ISO 817:2014 Refrigerants—Nomenclature and safety classification".

[0052] By selecting water, brine, or refrigerants conforming to "ISO 817:2014 Refrigerants - Nomenclature and safety classification" (such as ammonia (R717), R22, R32, R134a, or R290), and combining the control device to regulate the cooling medium supply parameters (usually including at least one of cooling medium type, cooling medium pressure, cooling medium temperature, and cooling medium flow rate), the cooling capacity of the indirect heat exchange condensate component 153 can be precisely adjusted for different operating conditions, ensuring that titanium tetrachloride flue gas can be efficiently condensed under various operating conditions, maintaining the temperature of the exhaust gas outlet 152 ≤70℃, and achieving full recovery of titanium tetrachloride.

[0053] Furthermore, there are at least two indirect heat exchange condensate components 153 arranged sequentially in the flow direction of the titanium tetrachloride flue gas, and the cooling medium supply parameters of the sequentially arranged indirect heat exchange condensate components 153 are independently adjustable.

[0054] A staged cooling system is formed by sequentially arranging at least two partitioned heat exchange condensate components 153 in the direction of titanium tetrachloride flue gas flow and independently adjusting the supply parameters of the cooling medium at each stage. This design enables the condensation device 15 to achieve precise temperature gradient control, optimize the heat exchange efficiency of each stage based on the thermodynamic characteristics of titanium tetrachloride flue gas at different condensation stages, and avoid local overcooling or insufficient heat exchange.

[0055] For example, in the initial stage when titanium tetrachloride flue gas enters the condenser 15, the first-stage indirect heat exchange condensate component 153 can use water as the cooling medium, controlling the water temperature within the range of 80℃-100℃ to provide moderate cooling intensity. This mainly addresses the sensible heat in the titanium tetrachloride flue gas and controls the initial cooling rate. This stage avoids impact condensation caused by rapid cooling, preventing the titanium tetrachloride vapor from becoming supersaturated and generating fine droplets, which could lead to decreased condensation efficiency or scaling on the pipe walls. As the flue gas temperature gradually decreases to approximately 140℃-120℃, the intermediate-stage indirect heat exchange condensate component 153 can use brine as the cooling medium, controlling the temperature within the range of 50℃-70℃. At this point, the cooling intensity increases, mainly addressing the latent heat of phase change of titanium tetrachloride from gaseous to liquid state. In this stage, efficient condensation of titanium tetrachloride is achieved through precise control of the cooling medium parameters. The final stage indirect heat exchange condensate component 153 can use a refrigerant (such as R134a or R22) as the cooling medium, setting the temperature in the range of 20°C to 40°C, treating residual vapor and ensuring the exhaust gas temperature drops to ≤70°C, and capturing trace amounts of titanium tetrachloride in the exhaust gas. These refrigerants can provide higher cooling efficiency.

[0056] The indirect heat exchange condensate component 153 can be made of tantalum finned heat exchange tubes or tantalum alloy finned heat exchange tubes. By using tantalum finned heat exchange tubes or tantalum alloy finned heat exchange tubes as key heat exchange elements, the material adaptability challenge of the titanium tetrachloride flue gas condensation device 15 in highly corrosive environments is solved. Tantalum and its alloys have excellent resistance to chlorine and titanium tetrachloride corrosion, and can maintain excellent mechanical properties and structural stability under high temperature conditions, while the fin design significantly improves the heat exchange surface area and heat exchange efficiency.

[0057] Furthermore, the titanium tetrachloride flue gas condensation device 15 also includes a heat recovery device for recovering and utilizing the heat energy carried out from the cooling medium and for recycling the cooling medium after cooling.

[0058] The heat recovery device can recover and utilize the heat energy carried out from the cooling medium (water, brine, or refrigerant such as R717, R22, R32, R134a, or R290) and realize the recycling of the cooling medium, forming a closed-loop energy management system. Specific feasible solutions include: the high-temperature cooling medium (80℃-100℃) of the first-stage indirect heat exchange condensate component 153 can be transferred to the factory heating system or preheat the materials entering the chlorination furnace 1 using a heat exchanger; the heat energy of the medium-temperature cooling medium (50℃-70℃) of the intermediate-stage indirect heat exchange condensate component 153 can be used for heating process water or producing low-temperature steam; the low-temperature cooling medium (20℃-40℃) of the final-stage indirect heat exchange condensate component 153 can be cooled by a cooling tower or plate heat exchanger and then recycled.

[0059] The condenser shell is typically a tower-shaped cylindrical design, with the product tank 154 located at the bottom of the condenser shell. In this case, when there are at least two indirect heat exchange condensate components 153, these components can be arranged sequentially along the height of the condenser shell.

[0060] Figure 3 This is a schematic diagram of the titanium tetrachloride crude preparation system of Embodiment 2 of this disclosure. Figure 5 for Figure 3 The diagram shows a scrubbing tower in the titanium tetrachloride crude product system. Figure 3 , Figure 5As shown, the titanium tetrachloride crude product system of Embodiment 1 of this disclosure includes: a dust removal unit for collecting dust from the titanium tetrachloride flue gas discharged from the chlorination furnace 1; a cooling unit for cooling the titanium tetrachloride flue gas after dust collection and collecting the titanium tetrachloride crude product while discharging tail gas with a temperature ≤70°C; and a post-cooling membrane filtration unit 17 for performing liquid-solid separation membrane filtration on the titanium tetrachloride crude product to obtain titanium tetrachloride crude product filtrate; wherein, the combined dust removal efficiency of the dust removal unit and the filtration efficiency of the post-cooling membrane filtration unit 17 can ensure that the solid mass percentage content in the titanium tetrachloride crude product filtrate is ≤0.1%; and, in the entire titanium tetrachloride flue gas flow path from the chlorination furnace 1 to the cooling unit, the titanium tetrachloride flue gas does not pass through any other cooling equipment except for natural cooling.

[0061] The titanium tetrachloride crude processing system in Example 2 introduces a post-cooling membrane filtration unit 17. By adding a dedicated liquid-solid separation membrane filtration process after the cooling unit, a dual filtration system is formed with the dust removal unit. The combined filtration efficiency of the two systems ensures that the solid mass percentage content in the crude titanium tetrachloride filtrate is ≤0.1%. Compared with the titanium tetrachloride crude processing system in Example 1, the titanium tetrachloride crude processing system in Example 2 retains the design that "the titanium tetrachloride flue gas does not pass through any cooling equipment except for natural cooling in the entire flow path of titanium tetrachloride flue gas from chlorination furnace 1 to the cooling unit." However, it shifts part of the technical burden of dust removal precision to the post-cooling membrane filtration unit 17. Compared with the scheme in Example 1, which mainly relies on the flue gas precision filtration dust collector 14 to achieve high dust removal efficiency, Example 2 allows the dust removal unit to have a relatively low dust removal efficiency, reducing the equipment requirements and resistance in the high-temperature flue gas stage. At the same time, the high purity standard of the final crude titanium tetrachloride is achieved through the post-cooling membrane filtration unit 17.

[0062] A dust removal unit typically includes a gravity dust collector 2 and / or a cyclone dust collector 3. When a dust removal unit includes a gravity dust collector 2 and a cyclone dust collector 3, the gravity dust collector 2 and the cyclone dust collector 3 are connected sequentially along the flow path of titanium tetrachloride flue gas.

[0063] The post-membrane filter unit 17 of the cooling unit employs a terminal filter or a cross-flow filter. The filter element in the terminal filter or cross-flow filter of the post-membrane filter unit 17 of the cooling unit is a porous material filter element with a filtration accuracy of ≤1 micrometer. Filtration accuracy refers to the smallest particle size that the filter element can retain, usually expressed in micrometers (μm). In the post-membrane filter unit 17 of the cooling unit, "filtration accuracy ≤1 micrometer" means that the filter element has the ability to retain a specific percentage (usually 90%-98%) of solid particles with a diameter greater than or equal to 1 micrometer. Empirically, a filter element filtration accuracy ≤1 micrometer is equivalent to an average pore size of ≤10 micrometers (i.e., 10 times the filtration accuracy).

[0064] As an improvement, a crude titanium tetrachloride storage tank 18 and an evaporation and condensation system are provided between the cooling unit and the post-cooling unit membrane filtration unit 17. The supernatant of the crude titanium tetrachloride storage tank 18 is filtered through the post-cooling unit membrane filtration unit 17 for liquid-solid separation. The underflow of the crude titanium tetrachloride storage tank 18 enters the evaporation mechanism 19 of the evaporation and condensation system for evaporation. The vapor generated by the evaporation process enters the condensation mechanism 20 of the evaporation and condensation system and is condensed into liquid before being filtered through the post-cooling unit membrane filtration unit 17 for liquid-solid separation.

[0065] This improved solution directly feeds the relatively clean supernatant into the post-cooling membrane filter unit 17 for processing, while the underflow containing higher levels of solid impurities is introduced into the evaporation mechanism 19 for evaporation and separation. The high-purity titanium tetrachloride vapor generated by evaporation is liquefied by the condensation mechanism 20 and then purified by the post-cooling membrane filter unit 17. This achieves efficient recovery of titanium tetrachloride while reducing the filtration load of the post-cooling membrane filter unit 17 and avoiding the risk of rapid clogging of the filter element.

[0066] The evaporation mechanism 19 can be a thin-film evaporator or a forced circulation evaporator, and the heating surface of the evaporation mechanism 19 is made of a material resistant to titanium tetrachloride corrosion. The condensation mechanism 20 is a shell-and-tube condenser or a plate condenser, and the surface of the condensation mechanism 20 that comes into contact with titanium tetrachloride is made of a material resistant to titanium tetrachloride corrosion.

[0067] The cooling unit in the titanium tetrachloride crude system of Example 2 specifically adopted... Figure 5 The scrubbing tower shown. (As shown in the image) Figure 5 As shown, the scrubbing tower 16 consists of two-stage series cold scrubbing towers, pump 161, chiller 162, and settling tank 163. The working principle is that after the titanium tetrachloride flue gas enters the cold scrubbing tower through the inlet 164, it comes into countercurrent contact with the circulating scrubbing liquid sprayed from the low-temperature titanium tetrachloride nozzle 165 and cooled by the chiller 162, causing the titanium tetrachloride flue gas to condense into liquid and be collected in the settling tank 163. At the same time, the exhaust gas with a temperature ≤70℃ is discharged through the condenser 166. The condenser 166 recovers a small portion of the titanium tetrachloride condensate and returns it to the settling tank 163 through the pipe 167. The supernatant formed in the settling tank 163 (which can be used as a crude titanium tetrachloride storage tank 18) is led out from the supernatant outlet 168 and sent to the post-membrane filter unit 17 of the cooling unit for treatment, while the bottom flow enters the evaporation and condensation system.

[0068] The titanium tetrachloride crude preparation system of Embodiment 3 of this disclosure is an improvement on the titanium tetrachloride crude preparation system of Embodiment 2 described above, using... Figure 4The titanium tetrachloride flue gas condensation device 15 shown replaces the above-mentioned scrubbing tower 16, avoiding the use of titanium tetrachloride liquid as a cooling medium and eliminating the problem of reduced titanium tetrachloride production caused by the recycling of titanium tetrachloride in the spray system.

[0069] When the cooling unit uses the titanium tetrachloride flue gas condensation device 15, the temperature of the titanium tetrachloride flue gas output from the dust removal unit in the titanium tetrachloride crude system of Example 3 entering the titanium tetrachloride flue gas condensation device 15 will be higher than that of the titanium tetrachloride flue gas output from the dust removal unit in the titanium tetrachloride crude system of Example 1 entering the titanium tetrachloride flue gas condensation device 15. Therefore, the indirect heat exchange condensate component 153 in the titanium tetrachloride flue gas condensation device 15 can be adaptively adjusted to four stages. This will further optimize the condensation efficiency and temperature control accuracy of the titanium tetrachloride flue gas. The design of the four-stage indirect heat exchange condensate component can achieve more precise temperature gradient control. The parameters of each stage can be set as follows: First-stage indirect heat exchange condensate component: High-temperature hot water is used as the cooling medium, and the hot water temperature is controlled within the range of 100℃-120℃ to achieve gentle cooling, mainly for pre-cooling, and avoid impact condensation. The second-stage indirect heat exchange condensate unit uses medium-temperature water as the cooling medium, with the water temperature controlled within the range of 70℃-90℃. At this stage, titanium tetrachloride vapor begins to partially condense, handling both sensible heat and some latent heat. This stage has high heat exchange efficiency, condensing approximately 30%-40% (by volume) of titanium tetrachloride vapor. The third-stage indirect heat exchange condensate unit uses low-temperature brine as the cooling medium, with the brine temperature controlled within the range of 40℃-60℃. This stage primarily handles the latent heat of phase change of titanium tetrachloride and is the main stage for titanium tetrachloride condensation, recovering approximately 50% (by volume) of the remaining titanium tetrachloride vapor. The fourth-stage indirect heat exchange condensate unit uses a refrigerant (such as R134a) as the cooling medium, with the refrigerant temperature controlled within the range of 10℃-30℃. This captures residual trace amounts of titanium tetrachloride vapor, ensuring the exhaust gas temperature is stably controlled at ≤70℃, meeting environmental emission requirements, while maximizing the recovery rate of titanium tetrachloride.

[0070] Figure 6 This is a schematic diagram of the titanium tetrachloride refining system according to Embodiment 1 of this disclosure. Figure 6 As shown, the titanium tetrachloride refining system of Embodiment 1 of this disclosure includes a refining unit and a pre-filtration membrane unit 21 for the refining unit. The refining unit receives crude titanium tetrachloride from the crude titanium tetrachloride system and purifies the crude titanium tetrachloride into refined titanium tetrachloride. The pre-filtration membrane unit 21 is used to perform liquid-solid separation membrane filtration on the crude titanium tetrachloride and obtain crude titanium tetrachloride filtrate, which is then input into the refining unit. The filtration efficiency of the pre-filtration membrane unit 21 is such that the solid mass percentage content in the crude titanium tetrachloride filtrate is ≤0.1%.

[0071] The refining unit is specifically a mineral oil refining unit, which includes: a mixer 8, used to mix the crude titanium tetrachloride filtrate output from the pre-membrane filtration unit 21 with mineral oil to obtain a mixture; an evaporator 9, used to evaporate the mixture to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and to obtain a clear evaporator and a slag evaporator; a distillation unit 11, used to distill the clear evaporator to obtain distilled gas and a slag evaporator, the slag evaporator containing high-boiling-point impurities relative to the boiling point of titanium tetrachloride; and a condenser 13, used to condense the distilled gas to obtain refined titanium tetrachloride product.

[0072] Among them, the pre-membrane filtration unit 21 of the refining unit adopts a terminal filter or a cross-flow filter, and the filter element in the terminal filter or cross-flow filter of the pre-membrane filtration unit 21 of the refining unit is a porous material filter element with a filtration accuracy of ≤1 micron.

[0073] The titanium tetrachloride refining system of Embodiment 1 of this disclosure introduces a pre-filtration membrane unit 21 as a key pretreatment step, achieving efficient liquid-solid separation membrane filtration of crude titanium tetrachloride in traditional production processes. This reduces the percentage of solids in the crude titanium tetrachloride filtrate input to the refining unit from the original 1%-2% to ≤0.1%, helping to solve key problems faced by existing titanium tetrachloride refining systems, such as unreasonable material circulation, improper slag and liquid treatment, accumulation of impurities, and significant environmental pollution. This solution can significantly reduce the generation of evaporation slag and distillation slag, reduce the amount of concentrated liquid phase that needs to be returned to chlorination furnace 1 and its impact on the thermal balance of the chlorination furnace, and reduce the discharge of waste liquid that needs to be neutralized with alkaline substances. It not only improves the comprehensive utilization rate and production efficiency of titanium tetrachloride resources, but also significantly reduces the risk of environmental pollution, providing a simple and efficient improvement solution for existing titanium tetrachloride production processes.

[0074] As a further improvement to the titanium tetrachloride refining system of Embodiment 1 of this disclosure, the titanium tetrachloride refining system may further include a solid-liquid separation unit and a post-solid-liquid separation membrane filtration unit 22; the solid-liquid separation unit is used to perform solid-liquid separation treatment on the concentrate, evaporation residue and distillation residue of the pre-refining membrane filtration unit 21 to obtain a clear liquid phase and a residue liquid phase; the post-solid separation membrane filtration unit 22 is used to perform liquid-solid separation membrane filtration treatment on the clear liquid phase and return the filtrate after liquid-solid separation membrane filtration treatment to the distillation apparatus 11 for distillation treatment.

[0075] This improvement, through the introduction of a solid-liquid separation unit and a post-solid-liquid separation membrane filtration unit 22, forms a closed-loop resource management system, solving core problems in the existing titanium tetrachloride refining section such as "unreasonable material circulation," "improper slag treatment," and "accumulation of impurities." By uniformly treating the concentrate, evaporation slag, and distillation slag from the pre-refining membrane filtration unit 21, the clear liquid phase obtained through solid-liquid separation is returned to the distillation unit 11 after efficient liquid-solid separation by the post-solid-liquid separation membrane filtration unit 22, significantly improving the recovery rate of titanium tetrachloride. Simultaneously, this improved design significantly reduces or even eliminates the amount of slag that needs to be returned to the chlorination furnace 1, avoiding the problem of "high liquid content in the concentrated liquid phase returned to the chlorination furnace 1 affecting the thermal balance of the chlorination furnace," and reducing coke consumption. More importantly, the precision filtration by the post-solid-liquid separation membrane filtration unit 22 effectively cuts off the path of impurity accumulation within the system, significantly improving the environmental performance and economic benefits of the titanium tetrachloride production system.

[0076] More specifically, the post-membrane filtration unit 22 of the solid-liquid separation unit adopts a terminal filter or a cross-flow filter, and the filter element of the terminal filter or cross-flow filter of the post-membrane filtration unit of the solid-liquid separation unit is a porous material filter element with a filtration accuracy of ≤0.1 micrometers. In addition, the concentrate of the post-membrane filtration unit 22 of the solid-liquid separation unit is returned to the solid-liquid separation unit through a return pipe.

[0077] The filter element of the terminal filter or cross-flow filter of the post-membrane filtration unit 22 of the solid-liquid separation unit is preferably an asymmetric porous material filter element, which performs filtration through a surface filtration layer. Preferably, the surface filtration layer is a sintered tantalum metal porous material layer or a sintered niobium metal porous layer.

[0078] Tantalum and niobium, as highly corrosion-resistant metals, maintain stable performance in the highly corrosive environment of titanium tetrachloride, greatly extending the service life of the filter element. Meanwhile, the asymmetric porous structure design gives the filter element higher porosity and better mechanical strength. When the surface filtration layer is a sintered porous tantalum or sintered porous niobium material layer, the cost of the filter element can be kept under control.

[0079] In addition, the solid-liquid separation unit includes a solid-liquid coarse separation device 23 and a dehydration device 24 connected in sequence. The solid-liquid coarse separation device 24 adopts a sedimentation tank, a concentrator or a centrifuge, and the dehydration device 24 adopts a press or a filter press.

[0080] This solid-liquid separation unit, through a series of connected solid-liquid coarse separation device 23 and dehydration device 24, forms a tiered separation system, achieving deep treatment of the slag and liquid. The solid-liquid coarse separation device 23 uses a settling tank, concentrator, or centrifuge to initially separate the concentrate, evaporation slag, and distillation slag, improving separation efficiency. Subsequently, the dehydration device 24 uses a press, filter press, or sealed evaporator to perform deep dehydration treatment on the material after solid-liquid coarse separation, significantly improving the recovery rate of titanium tetrachloride and enabling the solid-liquid separation unit to achieve a liquid mass percentage content of ≤10% in the slag-liquid phase, effectively solving the problem of limited initial dehydration effect of centrifuges 10 and 12 in the prior art.

[0081] There can be two independent solid-liquid coarse separation devices 24. One device simultaneously performs solid-liquid separation on the concentrate and evaporation residue from the pre-membrane filtration unit 21 of the refining unit, while the other device separately performs solid-liquid separation on the distillation residue. The solid-liquid coarse separation device that separately performs solid-liquid separation on the distillation residue has an insulated outer shell.

[0082] One solid-liquid coarse separation unit specifically processes the concentrate and evaporation residue from the pre-filtration membrane unit 21 of the refining unit, providing unified processing for these two relatively low-temperature and similar materials to improve equipment utilization. The other solid-liquid coarse separation unit separately processes the distillation residue and is equipped with an insulated outer shell, effectively solving the processing difficulties caused by high-boiling-point impurities relative to the boiling point of titanium tetrachloride in existing technologies. The insulated outer shell maintains the high temperature of the distillation residue, preventing the high-boiling-point impurities from cooling and solidifying, thus preventing decreased separation efficiency and equipment blockage. This improves the effective separation capability of vanadium and other impurity chlorides, solving the problem of impurity accumulation and the inability to effectively discharge vanadium and other impurity chlorides from the system. It also reduces the risk of wasting valuable resources and failing to effectively recover and utilize valuable impurities such as vanadium generated during the refining process, providing a more refined and resource-saving operating strategy for the titanium tetrachloride production system.

[0083] In addition, the solid-liquid separation unit may also include a slag-liquid phase collection device 25, which is used to collect and store the slag-liquid phase. The slag-liquid phase collection device 25 can systematically collect the slag-liquid phase after the desliming device 24, so that the slag-liquid phase does not need to be returned to the chlorination furnace 1.

[0084] Figure 7 This is a schematic diagram of the titanium tetrachloride refining system according to Embodiment 2 of this disclosure. Figure 7As shown, the titanium tetrachloride refining system of Embodiment 2 of this disclosure is an improvement on the titanium tetrachloride refining system of Embodiment 1 above, with a sealed baking device 26 installed after the solid-liquid separation unit. The sealed baking device 26 is used to perform sealed baking treatment on the slag-liquid phase to obtain titanium tetrachloride vapor and high-vanadium dry slag. The titanium tetrachloride vapor and the distilled gas enter the condenser 13 for condensation treatment.

[0085] In addition, a distillation device 27 is provided between the solid-liquid coarse separation device 23 and the sealed baking device 26. The distillation device 27 is used to distill the residue output from the solid-liquid coarse separation device 23 to obtain a distilled gas phase and a distilled concentrate. The distilled gas phase and titanium tetrachloride vapor enter the condenser 13 for condensation treatment, and the distilled concentrate enters the sealed baking device 26 for sealed baking treatment.

[0086] The titanium tetrachloride refining system of Embodiment 2 of this disclosure constructs a more closed-loop and efficient resource recovery system by adding a sealed baking device 26 and a distillation device 27 after the solid-liquid separation unit. The sealed baking device 26 performs deep treatment on the slag-liquid phase, achieving complete separation of titanium tetrachloride from impurities. The resulting titanium tetrachloride vapor directly enters the condenser 13 for recovery, while the high-vanadium dry slag is retained as a valuable byproduct. Furthermore, the distillation device 27 pre-treats the slag-liquid output from the solid-liquid coarse separation unit 23, separating it into a distillation vapor phase and a distillation concentrate. The distillation vapor phase and titanium tetrachloride vapor enter the condenser 13 together, while the distillation concentrate enters the sealed baking device 26 for deep treatment. This design completely solves the core problems of the prior art, such as the ineffective open-loop discharge of vanadium and other impurity chlorides and the waste of valuable resources. It achieves efficient recovery of titanium tetrachloride and effective extraction of vanadium resources, not only reducing environmental pollution risks but also transforming the problem of unreasonable material recycling into the advantage of comprehensive resource utilization. This significantly improves the economic efficiency and environmental protection level of the titanium tetrachloride production system, providing a comprehensive and systematic optimized solution for titanium tetrachloride refining technology.

[0087] As another embodiment of the titanium tetrachloride refining system of Embodiment 2 of this disclosure, the post-membrane filtration unit 22 of the solid-liquid separation unit can be omitted, and the clear liquid phase output from the solid-liquid coarse separation device can be returned to the mixture through a drainage pipe.

[0088] Figure 8 This is a schematic diagram of the titanium tetrachloride refining system according to Embodiment 3 of this disclosure. Figure 8As shown, the titanium tetrachloride refining system of Embodiment 3 of this disclosure is an improvement on the titanium tetrachloride refining system of Embodiment 2 above. A post-condensation membrane filtration unit 28 is added. This post-condensation membrane filtration unit 28 is used to further perform liquid-solid separation membrane filtration on the refined titanium tetrachloride product, so that the solid mass percentage content in the refined titanium tetrachloride product after liquid-solid separation membrane filtration does not exceed 0.01%. Specifically, the post-condensation membrane filtration unit 28 can be an ultrafiltration device.

[0089] This third embodiment of the present disclosure perfectly solves the potential risks that may arise from the setting of the distillation equipment 27 and the sealed baking device 26 by adding a post-condensation membrane filtration unit 28 as the final product purification stage. In Embodiment 2, the distillation vapor generated by the distillation equipment 27 and the titanium tetrachloride vapor released by the sealed baking device 26 directly enter the condensation device 13. Although this improves the recovery rate of titanium tetrachloride, it may also introduce trace amounts of impurities such as vanadium and chloride particles, affecting the purity of the final product. The post-condensation membrane filtration unit 28 can use an ultrafiltration device to deeply purify the refined titanium tetrachloride product, ensuring that the solid mass percentage content does not exceed 0.01%. This achieves precise control of product quality and resolves the contradiction between the two major goals of unreasonable material circulation and high product quality in the titanium tetrachloride refining system. It maximizes the recovery of titanium tetrachloride resources and ensures the ultra-high purity of the final product, effectively eliminating the risk of product quality fluctuations that may result from increased recovery rates.

[0090] In the above embodiments, the evaporator 9, distillation unit 11, and condensation unit 13 of the mineral oil refining unit are independent devices, which have problems such as large footprint, easy leakage of titanium tetrachloride during material transfer between devices, and high equipment investment costs. To address these issues, an integrated evaporation, distillation, and condensation device for titanium tetrachloride refining is proposed. This integrated device integrates the three functional units of evaporation, distillation, and condensation into a single tower, significantly reducing the footprint, eliminating material transfer links between devices, significantly reducing the risk of titanium tetrachloride leakage, and effectively reducing equipment investment costs by sharing some structural and control systems. This provides a safer, more economical, and more efficient technical solution for the titanium tetrachloride refining system.

[0091] Figure 9 This is a schematic diagram of the integrated evaporation, distillation, and condensation apparatus used in the purification of titanium tetrachloride in Example 1. Figure 9 As shown, the integrated evaporation, distillation and condensation apparatus for refining titanium tetrachloride includes a vertical outer cylinder 291 and a vertical inner cylinder 292 fitted inside the vertical outer cylinder 291. An external chamber is formed between the vertical outer cylinder 291 and the vertical inner cylinder 292, and an internal chamber is formed inside the vertical inner cylinder.

[0092] The upper part of the outer chamber forms a condensation chamber 29a, the lower part of the outer chamber forms an evaporation chamber 29b, the upper part of the inner chamber forms a cooling chamber 29c, and the lower part of the inner chamber forms a distillation chamber 29d. The lower part of the condensation chamber 29a and the upper part of the evaporation chamber 29b are separated by a partition. The lower part of the cooling chamber 29c and the upper part of the distillation chamber 29d are connected. The upper opening of the cooling chamber 29c is located in the condensation chamber 29a. An evaporation heating device 293 is provided at the evaporation chamber 29b, and a distillation heating device 294 is provided at the distillation chamber 29d.

[0093] The condensation chamber 29a is provided with a refined titanium tetrachloride product outlet 295, the evaporation chamber 29b is provided with a mixed liquid inlet 296, a low-boiling-point impurity outlet 297 and an evaporation residue outlet 298, the evaporation chamber 29b and the distillation chamber 29d are provided with an evaporation clear liquid guiding channel 299, and the distillation chamber 29d is provided with a distillation residue outlet 2910.

[0094] Evaporation chamber 29b is used to evaporate the mixture formed by crude titanium tetrachloride and mineral oil that enters the evaporation chamber 29b through the mixture inlet 296, to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and to obtain clear evaporation liquid and evaporation residue liquid. The low-boiling-point impurities are discharged from the low-boiling-point impurity outlet 297, the clear evaporation liquid enters the distillation chamber 29d through the clear evaporation liquid guide channel 299, and the evaporation residue liquid is discharged from the evaporation residue liquid outlet 298.

[0095] Distillation chamber 29d is used to distill the evaporated liquid to obtain distilled gas and distilled residue. The distilled residue contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride. The distilled residue is discharged from the distilled residue outlet 2910. The distilled gas rises and enters the cooling chamber 29c for cooling before entering the condensate chamber 29a.

[0096] The condensation chamber 29a is used to condense the cooled distilled gas to obtain purified titanium tetrachloride product, which is discharged from the purified titanium tetrachloride product outlet 295.

[0097] The integrated evaporation, distillation, and condensation apparatus for refining titanium tetrachloride in Example 1 innovatively integrates the evaporation chamber 29b, distillation chamber 29d, and condensation chamber 29a into a single vertical cylindrical structure, creating a highly integrated longitudinal material flow path. This integrated design fully utilizes the natural process of material handling. Starting from the evaporation chamber 29b, the evaporation heating device 293 efficiently removes low-boiling-point impurities. The evaporated liquid enters the distillation chamber 29d through the evaporated liquid guide channel 299, where the titanium tetrachloride vapor (distilled gas) is precisely separated by the distillation heating device 294. The distilled gas naturally rises into the cooling chamber 29c, and finally condenses in the condensation chamber 29a to transform into refined titanium tetrachloride product. This vertically integrated configuration not only fundamentally solves the core problems of large footprint of evaporator 9, distillation unit 11 and condensation unit 13, easy leakage of titanium tetrachloride during material transfer, and high equipment investment costs, but also achieves efficient separation and purification of materials in a closed environment through the ingenious design of the partition structure and the coaxial arrangement of the inner and outer cylinders. This greatly improves the safety, economy and energy utilization efficiency of the system, and provides a new solution for titanium tetrachloride refining technology that is compact, optimized in process and controllable in risk.

[0098] Optionally, the evaporation chamber 29b and / or the distillation chamber 29d are provided with inert gas inlets 2911. By providing inert gas inlets 2911 in the evaporation chamber 29b and / or the distillation chamber 29d, this integrated device achieves precise atmosphere control in the key reaction areas during the refining of titanium tetrachloride, effectively solving the risk of titanium tetrachloride being easily oxidized and hydrolyzed by oxygen and moisture during high-temperature processing. The introduction of inert gas not only removes residual active gases in the system but also forms a protective atmosphere, reducing the possibility of titanium tetrachloride coming into contact with oxygen and moisture.

[0099] As an improvement, a condensing chamber 29e is also provided in the area below the partition in the external chamber. The condensing chamber 29e is connected to the upper part of the evaporation chamber 29b, and the condensing chamber 29e is connected to the distillation chamber 29d through the evaporation liquid guide channel 299. The low boiling point impurity outlet 297 is located at the top of the condensing chamber 29e.

[0100] By adding a condensing chamber 29e below the partition of the external chamber, this improved design creates a more refined material separation path. The gaseous substances generated in the evaporation chamber 29b first enter the condensing chamber 29e for preliminary condensation and separation, achieving efficient separation of low-boiling-point impurities from titanium tetrachloride. The conductive design at the top of the condensing chamber 29e and the evaporation chamber 29b ensures that the gaseous substances generated during evaporation can flow naturally into the condensation area. The low-boiling-point impurity outlet 297 is located at the top of the condensing chamber 29e, allowing the low-boiling-point impurities to be discharged from the system after sufficient condensation of the titanium tetrachloride vapor. Simultaneously, the condensing chamber 29e is connected to the distillation chamber 29d via the clear liquid guide channel 299, forming an "evaporation-condensation-distillation" process. This allows the condensed titanium tetrachloride-enriched phase to flow directionally into the distillation chamber 29d for further purification. This improvement, by adding a dedicated condensing chamber 29e, enhances the separation selectivity of low-boiling-point impurities and the recovery rate of titanium tetrachloride, further strengthening the separation accuracy and operational flexibility of the integrated unit.

[0101] Furthermore, the vertical outer cylinder 291 is a first variable diameter cylinder having an upper diameter expansion section and a lower diameter contraction section. The condensate chamber 29a is located in the upper diameter expansion section of the first variable diameter cylinder, the evaporation chamber 29b is located in the lower diameter contraction section of the first variable diameter cylinder, and at least a portion of the condensation chamber 29e is located in the upper diameter expansion section of the first variable diameter cylinder.

[0102] The vertical outer cylinder 291 is designed as a first-diameter variable-diameter cylinder structure with an upper diameter expansion section and a lower diameter contraction section, which reflects the optimization of the geometry of the integrated device. This configuration places the condensate chamber 29a in the upper diameter expansion section, providing ample space for the condensation of gaseous substances, increasing the gas-liquid contact area and residence time, and improving condensation efficiency. Meanwhile, the evaporation chamber 29b is located in the lower diameter contraction section, forming a relatively concentrated heat zone, enhancing heat transfer efficiency, and reducing the size and energy consumption of the evaporation heating device 293. The design of the condensation chamber 29e being partially located in the upper diameter expansion section cleverly utilizes the space at the cylinder diameter change, creating more ideal conditions for the initial separation of low-boiling-point impurities from titanium tetrachloride.

[0103] A first cooling structure can be installed in the condensation chamber 29e. A second cooling structure can be installed in the condensate chamber 29a. Installing the first cooling structure in the condensation chamber 29e can effectively control the condensation rate and temperature gradient of the rising airflow in the evaporation chamber 29b, achieving precise separation of low-boiling-point impurities from titanium tetrachloride. This first cooling structure can be in the form of a coil, a cooling jacket, or a plate heat exchanger (i.e.,...). Figure 10The cooling medium in the condenser 29a (located at the top of the condensation chamber 29e) should be precisely controlled within a range below the boiling point of low-boiling-point impurities but slightly above the boiling point of titanium tetrachloride to ensure selective condensation. The second cooling structure in the condensate chamber 29a is designed for the efficient condensation of high-purity titanium tetrachloride vapor rising from the cooling chamber 29c. This second cooling structure can be designed as a spiral coil or a multi-layer plate heat exchanger (i.e.,...). Figure 9 Located at the top of the cooling chamber 29c, the temperature of the cooling medium should be appropriately lower than the freezing point of titanium tetrachloride to avoid the risk of blockage and maximize condensation efficiency. The temperature control systems of the first and second cooling structures can be adjusted independently to achieve precise control of the internal temperature field of the integrated device.

[0104] In addition, temperature sensors 2912 and / or pressure sensors 2913 are also provided in the condensation chamber 29a, evaporation chamber 29b, cooling chamber 29c, distillation chamber 29d, and condensation chamber 29e to monitor the process parameters of each functional area in real time.

[0105] Figure 10 This is a schematic diagram of the integrated evaporation, distillation, and condensation apparatus used in the purification of titanium tetrachloride in Example 2. Figure 10 As shown, the integrated evaporation, distillation and condensation apparatus for the purification of titanium tetrachloride in Embodiment 2 is an improvement on the integrated evaporation, distillation and condensation apparatus for the purification of titanium tetrachloride in Embodiment 1. After the improvement, an intermediate sleeve 2914 is provided in the area below the partition in the outer chamber, which is fitted between the vertical outer cylinder 291 and the vertical inner cylinder 292. The intermediate sleeve 2914 is spaced apart from the vertical outer cylinder 291 and the vertical inner cylinder 292 respectively. An evaporation chamber 29b is formed between the intermediate sleeve 2914 and the vertical inner cylinder, and a condensation chamber 29e is formed between the intermediate sleeve 2914 and the vertical outer cylinder 291.

[0106] In Example 2, an innovative three-cylinder coaxial nested structure is formed by adding an intermediate sleeve 2914 between the vertical outer cylinder 291 and the vertical inner cylinder 292. This design precisely confines the evaporation chamber 29b within the annular space between the intermediate sleeve 2914 and the vertical inner cylinder 292, while the condensation chamber 29e is located between the intermediate sleeve 2914 and the vertical outer cylinder 291. This concentric circular structure of "cylinder within a cylinder" significantly optimizes the heat and mass transfer path and space utilization of the integrated device. This improvement allows the gaseous substances generated by evaporation to enter the condensation chamber 29e from the evaporation chamber 29b along a clearly defined flow channel, forming a radial temperature gradient and concentration gradient, which enhances the separation effect of low-boiling-point impurities and titanium tetrachloride. At the same time, the three-cylinder structure effectively isolates different temperature zones, reduces heat loss, and improves energy utilization efficiency. The intermediate sleeve 2914 can also act as a physical barrier to prevent direct mixing of materials in the evaporation zone and the condensation zone, precisely controlling the residence time and flow direction of materials in each functional area. This structural design not only enhances the separation selectivity and operational stability of the device, but also achieves a more compact equipment layout and more precise process control through optimized space allocation.

[0107] Figure 11 This is a schematic diagram of the integrated evaporation, distillation, and condensation apparatus used in the purification of titanium tetrachloride in Example 3. Figure 11 As shown, the integrated evaporation, distillation and condensation apparatus for the purification of titanium tetrachloride in Example 3 includes a vertical cylinder 2915 and a condensation container 2916 that is connected to the upper part of the vertical cylinder 2915.

[0108] The lower part of the vertical cylinder 2915 forms an integrated evaporation and distillation chamber, and the upper part of the vertical cylinder 2915 forms a cooling chamber. The lower part of the cooling chamber is connected to the upper part of the integrated evaporation and distillation chamber. A condensate chamber is formed in the condensation container 2916. The upper opening of the cooling chamber is connected to the condensate chamber. An alternating evaporation heating device and a distillation heating device are provided at the integrated evaporation and distillation chamber.

[0109] The condensation chamber is equipped with a refined titanium tetrachloride product outlet 295, and the integrated evaporation and distillation chamber is equipped with a mixed liquid inlet 296, a low-boiling-point impurity outlet 297, an evaporation residue outlet, and a distillation residue outlet.

[0110] When the integrated evaporation and distillation chamber is used as an evaporation chamber, it is used to evaporate the mixture formed by crude titanium tetrachloride and mineral oil that enters the evaporation chamber through the mixed liquid inlet 296, remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain clear evaporation liquid and evaporation residue liquid. The low-boiling-point impurities are discharged from the low-boiling-point impurity outlet 297, the clear evaporation liquid is still stored in the integrated evaporation and distillation chamber, and the evaporation residue liquid is discharged from the evaporation residue liquid outlet.

[0111] When the integrated evaporation and distillation chamber is used as a distillation chamber, it is used to distill the evaporated liquid to obtain distilled gas and distilled residue. The distilled residue contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride. The distilled residue is discharged from the distilled residue outlet, and the distilled gas rises and enters the cooling chamber for cooling before entering the condensate chamber.

[0112] The condensation chamber is used to condense the cooled distilled gas to obtain purified titanium tetrachloride product, which is discharged from the purified titanium tetrachloride product outlet 295.

[0113] Example 3 proposes a simplified integrated evaporation, distillation, and condensation apparatus for the refining of titanium tetrachloride. By designing the lower part of the vertical cylinder 2915 as an integrated evaporation and distillation chamber and the upper part as a cooling chamber, connected to the condensation container 2916 to form a condensate chamber, an integrated system of "evaporation / distillation-cooling-condensation" vertical process is constructed. Its greatest innovation lies in combining the functions of the evaporation and distillation chambers into one. Alternating operation of the evaporation heating device and the distillation heating device achieves sequential separation of operations within the same space: first, the mixture of crude titanium tetrachloride and mineral oil is processed in the evaporation chamber to remove low-boiling-point impurities and obtain a clear evaporation liquid; then, it is converted into a distillation chamber to distill the clear evaporation liquid, separating high-boiling-point impurities. The resulting distilled gas enters the condensate chamber of the condensation container 2916 via the cooling chamber to obtain refined titanium tetrachloride product. This design significantly simplifies the equipment structure and process flow, reduces the connecting parts between mass transfer and heat transfer units, and lowers equipment costs and floor space. Simultaneously, it achieves time-separation instead of spatial separation in the processing, eliminating intermediate material transfer links and reducing energy loss and material consumption. This device is particularly suitable for intermittent production modes and small- to medium-scale titanium tetrachloride refining needs. Its simple and efficient design not only improves operational flexibility and maintenance convenience, but also ensures the purity and yield of titanium tetrachloride products through a streamlined process path.

[0114] Optionally, the integrated evaporation and distillation chamber is equipped with an inert gas inlet. Additionally, a cooling structure is provided in the condensate chamber. Furthermore, a condenser container 2916 is fitted onto the upper end of the vertical cylinder 2915.

[0115] Optionally, the vertical cylindrical body 2915 is a variable diameter cylindrical body with an upper diameter expansion section and a lower diameter contraction section. The cooling chamber is located in the upper diameter expansion section of the variable diameter cylindrical body, and the integrated evaporation and distillation chamber is located in the lower diameter contraction section of the variable diameter cylindrical body.

[0116] Optionally, the evaporation heating device and the distillation heating device are the same heating device 2917, and the heating power of the heating device 2917 when used as an evaporation heating device is lower than the heating power when used as a distillation heating device.

[0117] Optionally, the evaporation residue outlet and the distillation residue outlet are the same outlet 2918 and are located at the lower end of the vertical cylinder 2915. A control valve is provided at this outlet 2918.

[0118] The titanium tetrachloride refining system of Embodiment 4 of this disclosure, based on the titanium tetrachloride refining system of Embodiment 1, uses any of the above-mentioned integrated evaporation-distillation-condensation device for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0119] The titanium tetrachloride refining system of Embodiment 5 of this disclosure, based on the titanium tetrachloride refining system of Embodiment 2, uses any of the above-mentioned integrated evaporation-distillation-condensation device for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0120] The titanium tetrachloride refining system of Embodiment Six of this disclosure, based on the titanium tetrachloride refining system of Embodiment Three, uses any of the above-mentioned integrated evaporation-distillation-condensation device for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0121] Figure 12 This is a schematic diagram of the titanium tetrachloride purification system according to Embodiment Seven of this disclosure. Figure 12 As shown, the titanium tetrachloride refining system of Embodiment 7 of this disclosure includes a refining unit, which is a mineral oil refining unit. The mineral oil refining unit includes: a mixer 8, which is used to mix crude titanium tetrachloride with mineral oil to obtain a mixture; an evaporator 9, which is used to evaporate the mixture to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and to obtain a clear evaporator and a slag evaporator; a distillation apparatus 11, which is used to distill the clear evaporator to obtain a distilled gas and a slag evaporator, wherein the slag evaporator contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condenser 13, which is used to condense the distilled gas to obtain refined titanium tetrachloride product; and a low-boiling-point impurity condenser 30, which is used to recover low-boiling-point impurities that escape during the evaporation process of the evaporator and condense the low-boiling-point impurities into a liquid mixture rich in silicon tetrachloride.

[0122] The low-boiling-point impurity condenser 30 effectively captures and utilizes low-boiling-point impurities (mainly silicon tetrachloride) escaping from the evaporator, condensing them into a liquid mixture rich in silicon tetrachloride. This avoids material loss and environmental pollution caused by the emission of this material as waste gas. More importantly, silicon tetrachloride, as an important intermediate in the titanium chemical industry chain, has significant economic value and application prospects. By enriching and converting it into a usable product through a dedicated low-boiling-point impurity condenser, the economic benefits and resource utilization rate of the entire titanium tetrachloride production system are greatly improved.

[0123] Furthermore, the low-boiling-point impurity recovery system in the mineral oil refining unit has been further improved and optimized. For example... Figure 12 As shown, the low-boiling-point impurity condenser 30 condenses the low-boiling-point impurities discharged from the evaporator into a liquid mixture rich in silicon tetrachloride, and then the liquid mixture is introduced into the silicon tetrachloride distiller 31 for fine separation.

[0124] The silicon tetrachloride distiller 31 is specifically designed for distilling liquid mixtures, separating them into silicon tetrachloride vapor and a distillate. The distillate mainly contains titanium tetrachloride and small amounts of other impurities, while silicon tetrachloride, due to its low boiling point (approximately 57.6°C), preferentially vaporizes to form silicon tetrachloride vapor. The resulting silicon tetrachloride vapor enters the silicon tetrachloride vapor condenser 32, where it is condensed into liquid silicon tetrachloride product, achieving high-purity recovery of this valuable byproduct.

[0125] To achieve a closed-loop process and full utilization of materials, a distillation bottom liquid outlet is provided at the bottom of the silicon tetrachloride distiller 31, which is directly connected to the distillation unit 11 via a recovery pipeline. This design allows the distillation bottom liquid containing titanium tetrachloride to be returned to the distillation unit 11 for reprocessing, avoiding the loss of titanium tetrachloride and improving the material utilization efficiency of the system.

[0126] Preferably, the silicon tetrachloride distiller 31 employs a distillation column structure equipped with a precise temperature control system. This system ensures that the temperature at the bottom of the distillation column is maintained within a range above the boiling point of silicon tetrachloride (approximately 57.6°C) but below the boiling point of titanium tetrachloride (approximately 136.4°C), typically controlled between 60°C and 130°C; simultaneously, the temperature at the top of the distillation column is close to the boiling point of silicon tetrachloride, precisely controlled within the range of 55°C to 60°C. This temperature gradient design creates ideal separation conditions, allowing silicon tetrachloride to efficiently vaporize and rise to the top of the column, while titanium tetrachloride remains liquid and is discharged from the bottom.

[0127] The multi-plate structure of the distillation column provides ample gas-liquid contact area and mass transfer opportunities, ensuring efficient and selective separation. Precise temperature control within the column not only improves the purity of the silicon tetrachloride product but also minimizes the loss of titanium tetrachloride. This design embodies the precise control of separation processes and efficient resource utilization in fine chemical production, organically combining by-product recovery with main product refining, achieving a win-win situation for both economic benefits and environmental protection.

[0128] The titanium tetrachloride refining system of Embodiment 8 of this disclosure can be combined with the titanium tetrachloride refining systems of the other embodiments described above to form a more complete and efficient integrated refining solution. These combined implementation methods fully integrate the technical advantages of each embodiment, constructing a closed-loop, high-efficiency, and low-emission integrated titanium tetrachloride refining system.

[0129] The foregoing has described the relevant content of this disclosure. Those skilled in the art will be able to implement this disclosure based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of this disclosure.

Claims

1. A titanium tetrachloride flue gas condensation device, characterized in that: include: The condenser shell has a titanium tetrachloride flue gas inlet on its side, a tail gas outlet at its top, and a crude titanium tetrachloride outlet at its bottom; a partition wall heat exchange condensate component is disposed within the condenser shell and connected indirectly. The heat exchange method causes the titanium tetrachloride flue gas to condense into a liquid state; The product tank is connected to the outlet of the crude titanium tetrachloride and is used to collect titanium tetrachloride that has condensed into a liquid state. A cooling medium supply system is provided for supplying a cooling medium to the indirect heat exchange condensate component, wherein the cooling medium transfers heat from the titanium tetrachloride flue gas to the cooling medium through the indirect heat exchange condensate component. An adjustment device, connected to the cooling medium supply system, is used to adjust the cooling medium supply parameters to control the condensation effect on titanium tetrachloride flue gas.

2. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The cooling medium is water, salt water, or refrigerant.

3. The titanium tetrachloride flue gas condensation device as described in claim 2, characterized in that: The refrigerant is selected from any one of R717, R22, R32, R134a or R290 that conforms to "ISO 817:2014 Refrigerants—Nomenclature and safety classification".

4. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The indirect heat exchange condensate components consist of at least two units, arranged sequentially in the direction of titanium tetrachloride flue gas flow. The cooling medium supply parameters between the sequentially arranged indirect heat exchange condensate components are independently adjustable.

5. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: It includes a heat recovery device for recovering and utilizing the heat energy carried out from the cooling medium and for recycling the cooling medium after cooling it.

6. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The indirect heat exchange condensate component uses finned heat exchange tubes.

7. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The condenser shell is a tower-shaped cylindrical design, and the product tank is located at the bottom of the condenser shell.

8. The titanium tetrachloride flue gas condensation device as described in claim 7, characterized in that: The indirect heat exchange condensate components are at least two and are arranged sequentially along the height direction of the condenser shell.

9. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The cooling medium supply parameters include at least one of the following: cooling medium type, cooling medium pressure, cooling medium temperature, and cooling medium flow rate.

10. The titanium tetrachloride flue gas condensation device as described in claim 1, characterized in that: The indirect heat exchange condensate component uses tantalum finned heat exchange tubes or tantalum alloy finned heat exchange tubes.

Images