Titanium tetrachloride roughing system

Abstract

The invention discloses a titanium tetrachloride roughing system, which comprises: a dust removal unit, which is used for carrying out efficient dust collection treatment on titanium tetrachloride flue gas discharged from a chlorination furnace; the cooling unit is used for cooling the titanium tetrachloride flue gas subjected to the efficient dust collection treatment, collecting to obtain a titanium tetrachloride crude product and discharging tail gas with the temperature less than or equal to 70 DEG C at the same time; wherein the dust removal efficiency of the dust removal unit can enable the mass percentage content of solids in the titanium tetrachloride crude product collected by the cooling unit to be less than or equal to 0.1%; moreover, in the whole titanium tetrachloride flue gas flowing path formed from the chlorination furnace to the cooling unit, the titanium tetrachloride flue gas does not pass through other cooling equipment except for natural cooling. Solid impurities in the titanium tetrachloride crude product are remarkably reduced, and the purity of the titanium tetrachloride crude product is improved, so that the treatment burden of a subsequent titanium tetrachloride refining section is remarkably reduced, the slag liquid returning amount and resource waste are reduced, and the resource utilization rate and the production efficiency are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of titanium tetrachloride production. The embodiments of the present disclosure relate to a titanium tetrachloride crude system, a titanium tetrachloride refining system, a titanium tetrachloride flue gas condensing device used in the titanium tetrachloride crude system, an integrated evaporation, distillation and condensation device used for refining titanium tetrachloride used in the titanium tetrachloride refining system, and a low-boiling-point impurity recovery system used in the titanium tetrachloride refining system. Background Art

[0002] Currently, market demand for titanium tetrachloride is experiencing rapid growth. This is primarily driven by increased production of titanium sponge (prepared almost exclusively through titanium tetrachloride reduction, known as the Kroll process) and the widespread adoption of the chloride process in titanium dioxide production. Currently, few titanium dioxide manufacturers utilize the chloride process. However, due to its numerous advantages, including efficient resource utilization, minimal generation of solid and hazardous waste, minimal consumption of sulfur resources, and superior product quality, the chloride process is gradually replacing the traditional sulfuric acid process as the trend in the titanium dioxide industry.

[0003] The existing titanium tetrachloride production system consists of a crude titanium tetrachloride production process and a refined titanium tetrachloride production process. The crude titanium tetrachloride production process uses a chlorination furnace, dust collector, leaching tower, and other equipment to chlorinate and initially remove impurities from the titanium-containing raw material, producing a crude titanium tetrachloride product. The refined titanium tetrachloride production process primarily utilizes a mineral oil method to further remove impurities through mixing, evaporation, distillation, and condensation, ultimately producing the refined titanium tetrachloride product. However, existing titanium tetrachloride production technology remains relatively crude, resulting in inadequate resource utilization, high energy consumption, and significant environmental concerns. Summary of the Invention

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

[0005] In a first aspect, a crude titanium tetrachloride production system comprises: 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 a crude titanium tetrachloride product, and simultaneously discharging tail gas having a temperature of 70° C. or less. The dust removal efficiency of the dust removal unit enables the crude titanium tetrachloride product collected by the cooling unit to have a solid content of 0.1% or less by weight. Furthermore, in the entire titanium tetrachloride flue gas flow path formed 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] In a second aspect, a crude titanium tetrachloride production system comprises: 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 the dust collection treatment, collecting crude titanium tetrachloride and discharging tail gas with a temperature of ≤70°C; a post-cooling membrane filtration unit for filtering the crude titanium tetrachloride through a liquid-solid separation membrane 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 can ensure 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 formed 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] In a third aspect, a titanium tetrachloride flue gas condensation device comprises: a condenser shell, wherein the side of the condenser shell is provided with a titanium tetrachloride flue gas inlet, the top is provided with an exhaust gas outlet, and the bottom is provided with a crude titanium tetrachloride product outlet; a partition-type heat exchange condensation component, wherein the partition-type heat exchange condensation component is arranged 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 crude titanium tetrachloride product outlet and is used to collect the titanium tetrachloride condensed into a liquid state; a cooling medium supply system, wherein the cooling medium supply system is used to supply a cooling medium to the partition-type heat exchange condensation component, and the cooling medium transfers heat in the titanium tetrachloride flue gas to the cooling medium through the partition-type heat exchange condensation component; and a regulating device, wherein the regulating device is connected to the cooling medium supply system and is used to regulate the cooling medium supply parameters to control the condensation effect of the titanium tetrachloride flue gas.

[0008] In a fourth aspect, a titanium tetrachloride refining system comprises: a refining unit, which receives crude titanium tetrachloride from a titanium tetrachloride crude system and purifies the crude titanium tetrachloride into a refined titanium tetrachloride product; and a refining unit pre-membrane filtration unit, which is used to perform liquid-solid separation membrane filtration on the crude titanium tetrachloride to obtain a crude titanium tetrachloride filtrate, and then input the crude titanium tetrachloride filtrate into the refining unit; the filtration efficiency of the refining unit pre-membrane filtration unit can make the solid mass percentage content in the crude titanium tetrachloride filtrate ≤0.1%.

[0009] In a fifth aspect, a titanium tetrachloride refining system includes a refining unit, wherein the refining unit is a mineral oil refining unit, and the mineral oil refining unit includes: a mixer, wherein the mixer is used to mix crude titanium tetrachloride with mineral oil to obtain a mixed liquid; an evaporator, wherein the evaporator is used to evaporate the mixed liquid to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid; a distillation device, wherein the distillation device is used to distill the evaporation clear liquid to obtain a distillation gas and a distillation residue liquid, wherein the distillation residue liquid contains High-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condensing device, which is used to condense the distilled gas to obtain a refined titanium tetrachloride product; it also includes: a solid-liquid separation unit, which is used to perform solid-liquid separation on the evaporated slag liquid and the distilled slag liquid to obtain a clear liquid phase and a slag liquid phase; a membrane filtration unit is placed after the solid-liquid separation unit, and the membrane filtration unit is placed after the solid-liquid separation unit to perform liquid-solid separation membrane filtration on the clear liquid phase and return the filtrate after the liquid-solid separation membrane filtration to the distillation device for distillation.

[0010] In a sixth aspect, a titanium tetrachloride refining system includes a refining unit, wherein the refining unit is a mineral oil refining unit, and the mineral oil refining unit includes: a mixer, wherein the mixer is used to mix crude titanium tetrachloride with mineral oil to obtain a mixed liquid; an evaporator, wherein the evaporator is used to evaporate the mixed liquid to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid; a distillation device, wherein the distillation device is used to distill the evaporation clear liquid to obtain a distillation gas and a distillation residue liquid, wherein the distillation residue liquid contains High-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condensing device, which is used to condense the distilled gas to obtain a refined titanium tetrachloride product; it also includes: a solid-liquid separation unit, which is used to perform solid-liquid separation on the evaporated slag liquid and the distilled slag liquid to obtain a clear liquid phase and a slag liquid phase; a sealed baking device, which is used to perform a sealed baking treatment on the slag liquid phase to obtain titanium tetrachloride vapor and high-vanadium dry slag, and the titanium tetrachloride vapor and the distilled gas enter the condensing device together for condensation treatment.

[0011] In the seventh aspect, an integrated evaporation, distillation and condensation device for refining titanium tetrachloride comprises a vertical outer cylinder and a vertical inner cylinder sleeved in the vertical outer cylinder, an outer chamber is formed between the vertical outer cylinder and the vertical inner cylinder, an inner chamber is formed in the vertical inner cylinder; the upper part of the outer chamber forms a condensation chamber, the lower part of the outer chamber forms an evaporation chamber, the upper part of the inner chamber forms a cooling chamber, and the lower part of the inner chamber forms a distillation chamber, the lower part of the condensation chamber and the upper part of the evaporation chamber are separated 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 in the condensation chamber, the evaporation chamber is provided with an evaporation heating device, and the distillation chamber is provided with a distillation heating device; the condensation chamber is provided with a refined titanium tetrachloride product outlet, the evaporation chamber is provided with a mixed liquid inlet, a low-boiling point impurity outlet and an evaporation residue liquid outlet, an evaporation clear liquid diversion channel is provided between the evaporation chamber and the distillation chamber, The distillation chamber is provided with a distillation residue liquid outlet; the evaporation chamber is used to evaporate the mixed liquid formed by mixing crude titanium tetrachloride and mineral oil, which enters the evaporation chamber through the mixed liquid inlet, remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid, the low-boiling-point impurities are discharged from the low-boiling-point impurity outlet, the evaporation clear liquid enters the distillation chamber through the evaporation clear liquid guide channel, and the evaporation residue liquid is discharged from the evaporation residue liquid outlet; the distillation chamber is used to distill the evaporation clear liquid to obtain distillation gas and distillation residue liquid, the distillation residue liquid contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride, the distillation residue liquid is discharged from the distillation residue liquid outlet, the distillation gas rises and enters the cooling chamber for cooling and then enters the condensation chamber; the condensation chamber is used to condense the cooled distillation gas to obtain a refined titanium tetrachloride product, and the refined titanium tetrachloride product is discharged from the refined titanium tetrachloride product outlet.

[0012] In an eighth aspect, a titanium tetrachloride refining system comprises a refining unit, wherein the refining unit is a mineral oil refining unit, wherein the mineral oil refining unit comprises a mixer, and the mixer is used to mix crude titanium tetrachloride with mineral oil to obtain a mixed liquid; the mineral oil refining unit also comprises the integrated evaporation, distillation and condensation device for refining titanium tetrachloride according to the seventh aspect.

[0013] In the ninth aspect, an integrated evaporation, distillation and condensation device for refining titanium tetrachloride comprises a vertical cylinder and a condensation container connected to the upper part of the vertical cylinder; the lower part of the vertical cylinder forms an evaporation and distillation integrated cavity, the upper part of the vertical cylinder forms a cooling cavity, the lower part of the cooling cavity is connected to the upper part of the evaporation and distillation integrated cavity, a condensate cavity is formed in the condensation container, the upper opening of the cooling cavity is connected to the condensate cavity, and the evaporation and distillation integrated cavity is provided with an evaporation heating device and a distillation heating device that work alternately; the condensate cavity is provided with a refined titanium tetrachloride product outlet, the evaporation and distillation integrated cavity is provided with a mixed liquid inlet, a low-boiling point impurity outlet, an evaporation residue liquid outlet and a distillation residue liquid outlet; when the evaporation and distillation integrated cavity is used as an evaporation cavity, it is used to treat the crude titanium tetrachloride and mineral oil that enter the evaporation cavity through the mixed liquid inlet. The mixed liquid is evaporated to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and an evaporation supernatant and an evaporation residue liquid are obtained. The low-boiling-point impurities are discharged from the low-boiling-point impurity outlet. The evaporation supernatant is still stored in the evaporation-distillation integrated chamber, and the evaporation residue liquid is discharged from the evaporation residue liquid outlet. When the evaporation-distillation integrated chamber is used as a distillation chamber, it is used to distill the evaporation supernatant to obtain distillation gas and distillation residue liquid. The distillation residue liquid contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride. The distillation residue liquid is discharged from the distillation residue liquid outlet. The distillation gas rises and enters the cooling chamber to be cooled and then enters the condensation chamber. The condensation chamber is used to condense the cooled distillation gas to obtain a refined titanium tetrachloride product, which is discharged from the refined titanium tetrachloride product outlet.

[0014] In the tenth aspect, a titanium tetrachloride refining system includes a refining unit, wherein the refining unit is a mineral oil refining unit, and the mineral oil refining unit includes a mixer, and the mixer is used to mix crude titanium tetrachloride with mineral oil to obtain a mixed liquid; the mineral oil refining unit also includes the integrated evaporation, distillation and condensation device for refining titanium tetrachloride of the ninth aspect mentioned above.

[0015] In an eleventh aspect, a titanium tetrachloride refining system comprises a refining unit, wherein the refining unit is a mineral oil refining unit, and the mineral oil refining unit comprises: a mixer, wherein the mixer is used to mix crude titanium tetrachloride with mineral oil to obtain a mixed liquid; an evaporator, wherein the evaporator is used to evaporate the mixed liquid to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid; a distillation device, wherein the distillation device is used to distill the evaporation clear liquid to obtain a distillation gas and a distillation residue liquid, wherein the distillation residue liquid contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condensing device, wherein the condensing device is used to condense the distillation gas to obtain a refined titanium tetrachloride product; the mineral oil refining unit comprises a low-boiling-point impurity condenser, wherein the low-boiling-point impurities condenser is used to recover low-boiling-point impurities escaped during the evaporation process of the evaporator and condense the low-boiling-point impurities into a liquid mixture rich in silicon tetrachloride.

[0016] In the twelfth aspect, a low-boiling-point impurity recovery system is used in the titanium tetrachloride refining system of the eleventh aspect; it includes: a low-boiling-point impurity condenser, which is used to recover low-boiling-point impurities escaped during the evaporation process of the evaporator and condense the low-boiling-point impurities into a liquid mixture rich in silicon tetrachloride.

[0017] The above technical solution achieves the improvement of resource utilization, the reduction of production energy consumption and / or the reduction of environmental pollution by improving the crude titanium tetrachloride section and the refined section.

[0018] The present disclosure is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present disclosure will be partially given in the following description, partially become apparent from the following description, or be learned through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings that constitute a part of this specification are used to assist in understanding the present disclosure. The contents provided in the drawings and the related descriptions in this specification can be used to explain the present disclosure, but do not constitute improper limitations on the present disclosure.

[0020] Figure 1 Schematic diagram of the existing titanium tetrachloride production system.

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

[0022] Figure 3 This is a schematic diagram of a crude titanium tetrachloride system according to Example 2 of the present disclosure.

[0023] Figure 4 for Figure 2The schematic diagram of the titanium tetrachloride flue gas condensation device in the titanium tetrachloride crude system is shown.

[0024] Figure 5 for Figure 3 Schematic diagram of the elution tower in the titanium tetrachloride crude system.

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

[0026] Figure 7 This is a schematic diagram of a titanium tetrachloride refining system according to Example 2 of the present disclosure.

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

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

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

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

[0031] Figure 12 This is a schematic diagram of the titanium tetrachloride refining system of Example 7 of the present disclosure. DETAILED DESCRIPTION

[0032] The present disclosure is described clearly and completely below with reference to the accompanying drawings. A person of ordinary skill in the art will be able to implement the present disclosure based on these descriptions. Before describing the present disclosure with reference to the accompanying drawings, it should be noted that:

[0033] The technical solutions and technical features provided in each section, including the following description, may be combined with each other unless they conflict. In addition, where possible, these technical solutions, technical features, and related combinations may be assigned specific technical themes and protected by relevant patents.

[0034] The embodiments of the present disclosure involved in the following description are generally only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of patent protection.

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

[0036] Figure 1 The diagram of the existing titanium tetrachloride production system is shown in FIG. Figure 1 As shown, existing titanium tetrachloride production is divided into two major sections: the crude titanium tetrachloride section and the refined titanium tetrachloride section. In the crude titanium tetrachloride section, titanium-containing raw materials (high-titanium slag or titanium-rich ore) react with carbon and chlorine to form titanium tetrachloride. The titanium tetrachloride exits the chlorination furnace 1 in gaseous form along with high-temperature furnace gases (commonly known as titanium tetrachloride flue gas). The flue gas undergoes a primary cooling spray (using room-temperature titanium tetrachloride liquid, which comes from a subsequent thickener) to reduce its temperature to 200°C-250°C. The flue gas then undergoes dust removal (gravity dust collector 2 and cyclone dust collector 3) before entering a leaching tower 4. The leaching tower 4 uses a low-temperature titanium tetrachloride liquid for cold leaching (secondary cooling spray, using the low-temperature titanium tetrachloride liquid from the cooled room-temperature titanium tetrachloride liquid). This converts the gaseous titanium tetrachloride into a liquid form, which is then recovered along with the dust into a slag liquid tank 5. After overflowing from the slag tank 5 and concentrating it in the thickener 6, the supernatant passes through multiple settling tanks 7 for a prolonged period of time (over 48 hours). The crude titanium tetrachloride product currently contains approximately 1% to 2% solids by weight. This crude titanium tetrachloride also contains impurities with similar melting and boiling points to titanium tetrachloride (such as chlorides of vanadium, aluminum, iron, and silicon), requiring further treatment to remove impurities. The resulting refined liquid is the refined titanium tetrachloride product. The slag liquid from the slag tank 5, thickener 6, and settling tank 7 is then returned to the chlorination furnace for processing. Excessive return can affect the chlorination furnace's thermal balance, and any slag liquid that cannot be returned to the furnace is neutralized in water with an alkaline solution.

[0037] like Figure 1As shown, the titanium tetrachloride refining process typically utilizes a mineral oil refining process. Currently, the mineral oil refining process is as follows: First, crude titanium tetrachloride enters a mixer 8, which mixes it with mineral oil to produce a mixed liquid. The mixed liquid then enters an evaporator 9, which evaporates the mixed liquid (typically heated to 120°C-140°C) to remove impurities with low boiling points relative to the boiling point of titanium tetrachloride (low-boiling-point impurities escape in gaseous form), producing a clear evaporated liquid (titanium tetrachloride liquid with low-boiling-point impurities removed) and an evaporated slag liquid. During the evaporation process, the mineral oil dispersed in the titanium tetrachloride carbonizes and reacts with chlorides (such as vanadium oxychloride) with boiling points similar to titanium tetrachloride, producing high-melting and high-boiling-point substances (such as vanadium trichloride and vanadium tetrachloride), which settle to the bottom of the evaporator. This, combined with substances introduced by the mineral oil that do not participate in the reaction and solid particles introduced by the crude titanium tetrachloride, forms an evaporated slag liquid. The evaporation residue is viscous and is typically initially deliquated by sedimentation or a centrifuge 10. The liquid phase then returns to the evaporator 9 for further evaporation, while a portion of the concentrated liquid phase is returned to the chlorination furnace 1, while another portion is partially placed in water and neutralized with an alkaline solution. The evaporated liquid then enters a distillation unit 11 (typically a rectification column), which distills the evaporated liquid (heating temperature generally controlled above 135°C) to produce distilled gas (titanium tetrachloride vapor) and a distilled residue liquid. The distilled residue liquid contains impurities with a high boiling point relative to the boiling point of titanium tetrachloride. Initially deliquated by sedimentation or a centrifuge 12, the liquid phase then returns to the distillation unit 11 for further distillation. A portion of the concentrated liquid phase is returned to the chlorination furnace 1, while another portion is partially placed in water and neutralized with an alkaline solution. Finally, the distilled gas enters a condenser 13, which condenses the distilled gas to produce the refined titanium tetrachloride product.

[0038] However, the above-mentioned titanium tetrachloride production system has significant problems in both the crude titanium tetrachloride section and the refined titanium tetrachloride section. In the crude titanium tetrachloride section, the main problems are: low solid-liquid separation efficiency, excessive settling time in the settling tank 7 and almost no effect on fine particles, resulting in a crude titanium tetrachloride solid content of up to 1%-2% by weight; inadequate utilization of titanium resources, with the sedimentation slag liquid in the slag liquid tank 5, thickener 6, and settling tank 7 containing a large amount of titanium tetrachloride, which affects the thermal balance of the chlorination furnace when returned to the chlorination furnace 1, while the use of alkaline neutralization treatment results in a waste of titanium tetrachloride resources; excessive energy consumption, with large amounts of returned slag liquid disrupting the original reaction thermal balance in the chlorination furnace, increasing coke consumption, and consuming a large amount of energy for primary and secondary cooling sprays; and severe environmental pollution, with the titanium tetrachloride-containing sedimentation slag liquid that cannot be returned to the furnace requiring neutralization treatment with alkaline substances, generating large amounts of hazardous wastewater and gas emissions. In the titanium tetrachloride refining section, the main problems are: unreasonable material circulation, low slag liquid treatment efficiency in the evaporator 9 and the distillation device 11, and large amounts of return processing causing energy waste; improper slag liquid treatment, the evaporated slag liquid and the distilled slag liquid contain a large amount of titanium tetrachloride, and the initial deliquescence effect of the centrifuge 10 and the centrifuge 12 is limited, resulting in a high liquid content in the concentrated liquid phase returned to the chlorination furnace 1, affecting the thermal balance of the chlorination furnace; impurities accumulate in the circulation, and impurity chlorides such as vanadium cannot be effectively discharged from the system, and the circulation accumulation leads to a gradual deterioration of process conditions; valuable resources are wasted, and valuable impurities such as vanadium generated during the refining process cannot be effectively recycled and utilized; environmental pollution is prominent, and part of the concentrated liquid phase needs to be put into water and neutralized with alkaline substances, causing secondary pollution.

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

[0040] The titanium tetrachloride crude system of the first embodiment of the present disclosure can first reduce the solid mass percentage content in the titanium tetrachloride crude product to ≤0.1%, significantly reduce the solid impurities in the titanium tetrachloride crude product, and improve the purity of the titanium tetrachloride crude product, thereby significantly reducing the processing burden of the subsequent titanium tetrachloride refining section, reducing the amount of returned slag liquid and resource waste, and improving 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 leaching tower in the cooling unit, if the tail gas temperature is to be reduced to ≤70°C to fully recover titanium tetrachloride, a large amount of energy must be consumed (when the dust content in the titanium tetrachloride flue gas is high, a large amount of dust particles will hinder the direct contact between the titanium tetrachloride flue gas and the leaching liquid, and the dust particles may reduce the atomization effect of the leaching liquid, thereby weakening the gas-liquid heat exchange and condensation efficiency). The titanium tetrachloride crude production system of Example 1 of the present disclosure improves the dust removal efficiency of the dust removal unit, reducing the solid mass percentage of the crude titanium tetrachloride collected by the cooling unit to ≤0.1%. 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, due to the ability to efficiently reduce the temperature and ensure the full recovery of titanium tetrachloride in the exhaust gas, the original primary cooling spray is no longer required, thereby simplifying the process flow, further reducing energy consumption, and significantly improving the economic and environmental performance of the titanium tetrachloride crude production system.

[0041] Specifically, the dust removal unit includes at least two stages of dust collectors, and at least the rear stage of the at least two stages of dust collectors adopts a flue gas precision filter dust collector 14; the filter element of the flue gas precision filter dust collector 14 can withstand the temperature of the titanium tetrachloride flue gas to be filtered and has chlorine corrosion resistance, and can also achieve a dust content of the filtered titanium tetrachloride flue gas ≤5mg / Nm 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 filtration dust collector 14 adopts a metal sintered filter element with Hastelloy C-276 as the main material. Hastelloy C-276 is a nickel-based corrosion-resistant alloy mainly composed of elements such as nickel, molybdenum, chromium, and iron, and has excellent corrosion resistance and mechanical properties. Its high content of nickel and molybdenum gives it excellent corrosion resistance to strong oxidizing and reducing media (such as wet chlorine, chloride solution, etc.). The addition of chromium enhances its antioxidant properties, 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 equipment, flue gas filter elements, etc., and can operate stably for a long time and significantly extend the service life of the equipment. From the perspective of structural performance, the metal sintered filter element has a precise pore structure, which can not only achieve high-efficiency filtration, but also ensure the mechanical strength and durability of the filter element, effectively reducing operation and maintenance costs.

[0044] In addition, the applicant may also perform the following surface treatments on the aforementioned metal sintered filter element: Step 1: Electrochemical polishing of the main material surface to form an initial passivation layer rich in chromium and molybdenum with a surface roughness Ra of 0.2μm-0.3μm; Step 2: Anodization of the initial passivation layer surface to form an oxide layer with a thickness of 50nm-80nm and primarily comprising Cr2O3, MoO3, and NiO; Step 3: Passivation treatment of the oxide layer surface to form a stable passivation layer rich in chromium and molybdenum; the passivation agent comprises a high-oxidation-state chromium salt, a molybdate, and hydrofluoric acid.

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

[0046] The at least two-stage dust collector may generally include a gravity dust collector 2, a cyclone dust collector 3 and a flue gas precision filtration dust collector 14 which are connected in sequence along the flow path of the titanium tetrachloride flue gas.

[0047] Alternatively, the at least two-stage dust collector may include a gravity dust collector 2 and a flue gas precision filtration dust collector 14 connected in sequence along the flow path of the titanium tetrachloride flue gas.

[0048] Alternatively, at least two stages of dust collectors include a cyclone dust collector 3 and a flue gas precision filtering dust collector 14 which are connected in sequence along the flow path of the titanium tetrachloride flue gas.

[0049] Furthermore, the cooling unit also uses a titanium tetrachloride flue gas condensation device 15. Figure 4 As shown, the titanium tetrachloride flue gas condensing device 15 includes: a condenser shell, which is provided with a titanium tetrachloride flue gas inlet 151 on the side, an exhaust gas outlet 152 on the top, and a crude titanium tetrachloride product outlet at the bottom; a partition-type heat exchange condensation 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 crude titanium tetrachloride product outlet and is used to collect the titanium tetrachloride condensed into a liquid state (the product tank 154 is provided with a drain port 158 for discharging the crude titanium tetrachloride). A cooling medium supply system 155 is used to supply cooling medium to the partition-type heat exchange condensation component 153 (the cooling medium supply system 155 is connected to the partition-type heat exchange condensation component 153 through a cooling medium input pipe 156 and a cooling medium output pipe 156 to realize the flow of the cooling medium). The cooling medium transfers heat in the titanium tetrachloride flue gas to the cooling medium through the partition-type heat exchange condensation component 153; a regulating 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 unit 15 utilizes a partition-type heat exchange condensation element 153 to achieve indirect heat exchange. This allows the titanium tetrachloride flue gas, which has been efficiently treated by the flue gas precision filter dust collector 14, to be condensed into liquid titanium tetrachloride through heat transfer to the cooling medium. This condensation is then collected in the product tank 154 as crude titanium tetrachloride. The most significant significance of this design is that it completely replaces the primary and secondary cooling spray methods used in traditional processes, eliminating the use of liquid titanium tetrachloride as a cooling medium and addressing the issue of reduced titanium tetrachloride production caused by the recycling of titanium tetrachloride in the spray system. Combined with a high-efficiency front-end dust removal unit (solids content ≤ 0.1% by mass), condensation efficiency is significantly improved, ensuring an exhaust temperature of ≤70°C and sufficient titanium tetrachloride recovery. This significantly simplifies the process flow and reduces energy consumption, fundamentally addressing key issues in the traditional crude production process, such as low solid-liquid separation efficiency, inadequate titanium resource utilization, and excessive energy consumption.

[0051] The cooling medium may be water, brine, or a refrigerant. Further, the refrigerant is selected from at least one of ammonia (R717), R22, R32, R134a, or R290 that complies with ISO 817:2014 Refrigerants — Designation and safety classification.

[0052] By selecting water, brine or a refrigerant that complies with "ISO 817:2014 Refrigerants — Designation and Safety Classification Standard" (such as ammonia (R717), R22, R32, R134a or R290), combined with the regulation of the cooling medium supply parameters (usually including at least one of the cooling medium type, cooling medium pressure, cooling medium temperature, and cooling medium flow rate) by the regulating device, the cooling capacity of the partition-type heat exchange condensation component 153 can be accurately adjusted according to different operating conditions, ensuring that the titanium tetrachloride flue gas can be efficiently condensed under various operating conditions, maintaining the temperature of the exhaust gas outlet 152 ≤70°C, and achieving full recovery of titanium tetrachloride.

[0053] Furthermore, there are at least two partition-type heat exchange condensation components 153 which are sequentially arranged in the flow direction of the titanium tetrachloride flue gas, and the cooling medium supply parameters between the sequentially arranged partition-type heat exchange condensation components 153 are independently adjusted.

[0054] By sequentially placing at least two partition-type heat exchange condensation components 153 in the direction of the titanium tetrachloride flue gas flow and independently adjusting the cooling medium supply parameters at each stage, a staged cooling system is formed. This design enables precise temperature gradient control of the condensing device 15. Based on the thermodynamic characteristics of the titanium tetrachloride flue gas at different condensation stages, the heat exchange efficiency of each stage is optimized to avoid localized overcooling or insufficient heat exchange.

[0055] For example, when the titanium tetrachloride flue gas initially enters the condensing unit 15, the first-stage inter-wall heat exchange condensation unit 153 can use water as the cooling medium, with the water temperature controlled within the range of 80°C-100°C. This provides moderate cooling intensity, primarily treating the sensible heat in the titanium tetrachloride flue gas and controlling the initial cooling rate. This stage avoids shock condensation caused by rapid cooling, preventing the titanium tetrachloride vapor from suddenly cooling to a supersaturated state and producing fine droplets, which could reduce condensation efficiency or cause scaling on the tube walls. As the flue gas temperature gradually decreases to approximately 140°C-120°C, the intermediate-stage inter-wall heat exchange condensation unit 153 can use brine as the cooling medium, with the temperature controlled within the range of 50°C-70°C. At this point, the cooling intensity increases, primarily treating the latent heat of the phase change from gas to liquid of the titanium tetrachloride. Precise control of the cooling medium parameters during this stage enables efficient condensation of the titanium tetrachloride. The final interstage heat exchange condensate component 153 can use a refrigerant (such as R134a or R22) as the cooling medium, set at a temperature between 20°C and 40°C, to process the remaining steam and ensure that the exhaust temperature drops to ≤70°C, capturing trace amounts of titanium tetrachloride in the exhaust gas. These refrigerants can provide higher cooling efficiency.

[0056] Tantalum finned heat exchange tubes or tantalum alloy finned heat exchange tubes can be used in the partition-type heat exchange condensation component 153. By using tantalum finned heat exchange tubes or tantalum alloy finned heat exchange tubes as key heat exchange components, the material adaptability challenge of the titanium tetrachloride flue gas condensation device 15 in highly corrosive environments is resolved. Tantalum and its alloys have excellent corrosion resistance to chlorine and titanium tetrachloride, maintaining excellent mechanical properties and structural stability even under high temperature conditions. The fin design significantly increases the heat exchange surface area and heat exchange efficiency.

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

[0058] The heat recovery device can recycle and reuse the heat removed from the cooling medium (water, brine, or refrigerants such as R717, R22, R32, R134a, or R290) and recycle the cooling medium, forming a closed-loop energy management system. Specific feasible solutions include: using a heat exchanger to transfer the high-temperature cooling medium (80°C-100°C) in the first-stage interlayer heat exchange condensate component 153 to the factory heating system or to preheat the materials entering the chlorination furnace 1; the medium-temperature cooling medium (50°C-70°C) in the intermediate-stage interlayer heat exchange condensate component 153 can be used to heat process water or produce low-temperature steam; and the low-temperature cooling medium (20°C-40°C) in the final-stage interlayer heat exchange condensate component 153 can be cooled by a cooling tower or plate heat exchanger before being recycled.

[0059] The condenser shell is usually designed as a tower cylinder, and the product tank 154 is located at the lower part of the condenser shell. At this time, when there are at least two partition-type heat exchange condensation components 153, these partition-type heat exchange condensation components 153 can be arranged in sequence in the height direction of the condenser shell.

[0060] Figure 3 This is a schematic diagram of a crude titanium tetrachloride system according to Example 2 of the present disclosure. Figure 5 for Figure 3 The schematic diagram of the elution tower in the titanium tetrachloride crude system is shown in FIG. Figure 3 、 Figure 5As shown, the crude titanium tetrachloride system of the first embodiment of the present disclosure includes: a dust removal unit, which is used to collect dust from the titanium tetrachloride flue gas discharged from the chlorination furnace 1; a cooling unit, which is used to cool the titanium tetrachloride flue gas after the dust collection treatment, and collect the crude titanium tetrachloride while discharging the tail gas with a temperature of ≤70°C; a membrane filtration unit 17 after the cooling unit, which is used to perform liquid-solid separation membrane filtration on the crude titanium tetrachloride to obtain a crude titanium tetrachloride filtrate; wherein the dust removal efficiency of the dust removal unit and the filtration efficiency of the membrane filtration unit 17 after the cooling unit are combined to make the solid mass percentage content in the crude titanium tetrachloride filtrate ≤0.1%; and, in the entire titanium tetrachloride flue gas flow path formed from the chlorination furnace 1 to the cooling unit, the titanium tetrachloride flue gas does not pass through other cooling equipment except for natural cooling.

[0061] The crude titanium tetrachloride system of Example 2 incorporates a post-cooling membrane filtration unit 17. By adding a specialized liquid-solid separation membrane filtration process after the cooling unit, this system forms a dual filtration system with the dust removal unit. The combined filtration efficiency of these two processes ensures that the solid content of the crude titanium tetrachloride filtrate is ≤0.1% by weight. Compared to the crude titanium tetrachloride system of Example 1, the crude titanium tetrachloride system of Example 2 retains the design of "the titanium tetrachloride flue gas does not pass through any other cooling equipment except for natural cooling throughout the entire titanium tetrachloride flue gas flow path from the chlorination furnace 1 to the cooling unit." However, the technical burden of dust removal accuracy is partially shifted to the post-cooling membrane filtration unit 17. Compared to Example 1, which primarily 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 lower dust removal efficiency, reducing equipment requirements and resistance in the high-temperature flue gas stage. Furthermore, the post-cooling membrane filtration unit 17 achieves a high purity standard for the final crude titanium tetrachloride product.

[0062] The dust removal unit generally includes a gravity dust collector 2 and / or a cyclone dust collector 3. When the dust removal unit includes the gravity dust collector 2 and the cyclone dust collector 3, the gravity dust collector 2 and the cyclone dust collector 3 are sequentially connected in front and back according to the flow path of the titanium tetrachloride flue gas.

[0063] The cooling unit post-membrane filtration unit 17 uses a terminal filter or a cross-flow filter. The filter element in the terminal filter or cross-flow filter of the cooling unit post-membrane filtration unit 17 is a porous material filter element with a filtration accuracy of ≤1 micron. Filtration accuracy refers to the minimum particle size that the filter element can retain, usually expressed in microns (μm). In the cooling unit post-membrane filtration unit 17, "filtration accuracy ≤1 micron" 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 micron. According to experience, a filter element filtration accuracy of ≤1 micron is equivalent to the average pore size of the filter element being ≤10 microns (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-membrane filtration unit 17 of the cooling unit. The supernatant of the crude titanium tetrachloride storage tank 18 is subjected to liquid-solid separation membrane filtration treatment through the post-membrane filtration unit 17 of the cooling unit, and the bottom flow of the crude titanium tetrachloride storage tank 18 enters the evaporation mechanism 19 of the evaporation and condensation system for evaporation treatment. The vapor generated by the evaporation treatment enters the condensation mechanism 20 of the evaporation and condensation system and is condensed into liquid and then passes through the post-membrane filtration unit 17 of the cooling unit for liquid-solid separation membrane filtration treatment.

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

[0066] The evaporation mechanism 19 may 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 may be a shell and tube condenser or a plate condenser, and the surface of the condensation mechanism 20 that contacts the 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 adopts Figure 5 The eluent shown in Figure 1 is a elution tower. Figure 5 As shown, the elution tower 16 consists of a two-stage series-connected cold elution tower, a pump 161, a refrigerator 162, and a liquid clarifier 163. The working principle is that after the titanium tetrachloride flue gas enters the cold elution tower from the air inlet 164, it contacts the circulating eluent sprayed from the low-temperature titanium tetrachloride nozzle 165 and cooled by the refrigerator 162 in countercurrent, so that the titanium tetrachloride flue gas is condensed into a liquid and collected in the liquid clarifier 163. At the same time, the exhaust gas with a temperature of ≤70°C is discharged through the condenser 166. The condenser 166 recovers a small portion of the titanium tetrachloride condensate and returns it to the liquid clarifier 163 through the pipeline 167; the supernatant formed in the liquid clarifier 163 (which can be used as the crude titanium tetrachloride storage tank 18) is drawn out from the supernatant outlet 168 and sent to the cooling unit post-membrane filtration unit 17 for treatment, and the bottom underflow enters the evaporation and condensation system.

[0068] The titanium tetrachloride crude system of the third embodiment of the present disclosure is improved on the basis of the titanium tetrachloride crude system of the second embodiment above, and uses Figure 4The titanium tetrachloride flue gas condensing device 15 shown replaces the above-mentioned leaching 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 utilizes 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 upon entering the titanium tetrachloride flue gas condensation device 15 is higher than the temperature of the titanium tetrachloride flue gas output from the dust removal unit in the titanium tetrachloride crude system of Example 1 upon entering the titanium tetrachloride flue gas condensation device 15. Therefore, the partition wall heat exchange condensation component 153 in the titanium tetrachloride flue gas condensation device 15 can be adaptively adjusted to four stages, which will further optimize the condensation efficiency and temperature control accuracy of the titanium tetrachloride flue gas. The design of the four-stage partition wall heat exchange condensation component enables more precise temperature gradient control, and the parameters of each stage can be set as follows: First-stage partition wall heat exchange condensation component: High-temperature hot water is used as the cooling medium, and the hot water temperature is controlled within the range of 100°C-120°C to achieve gentle cooling, focusing on pre-cooling to avoid shock condensation. The second-stage heat exchanger / condenser utilizes medium-temperature water, controlled within a temperature range of 70°C-90°C. During this stage, the titanium tetrachloride vapor begins to partially condense, disposing of both sensible and latent heat. This stage boasts high heat transfer efficiency, condensing approximately 30%-40% (volume percentage) of the titanium tetrachloride vapor. The third-stage heat exchanger / condenser utilizes low-temperature brine, controlled within a temperature range of 40°C-60°C. This stage primarily disposes of the latent heat of phase change and is the primary stage of titanium tetrachloride condensation, recovering approximately 50% (volume percentage) of the remaining titanium tetrachloride vapor. The fourth-stage heat exchanger / condenser utilizes a refrigerant (such as R134a) controlled within a temperature range of 10°C-30°C. This captures trace amounts of residual titanium tetrachloride vapor, ensuring a stable exhaust temperature of ≤70°C, meeting environmental emission requirements while maximizing titanium tetrachloride recovery.

[0070] Figure 6 Schematic diagram of the titanium tetrachloride refining system according to the first embodiment of the present disclosure. Figure 6 As shown, the titanium tetrachloride refining system of the first embodiment of the present disclosure includes a refining unit and a refining unit pre-membrane filtration unit 21; the refining unit receives crude titanium tetrachloride from the titanium tetrachloride crude system and purifies the crude titanium tetrachloride into a refined titanium tetrachloride product; the refining unit pre-membrane filtration unit 21 is used to perform liquid-solid separation membrane filtration on the crude titanium tetrachloride to obtain a crude titanium tetrachloride filtrate, and then input the crude titanium tetrachloride filtrate into the refining unit. The filtration efficiency of the refining unit pre-membrane filtration unit 21 can make the solid mass percentage content in the crude titanium tetrachloride filtrate ≤0.1%.

[0071] Among them, the refining unit is specifically a mineral oil refining unit, and the mineral oil refining unit includes: a mixer, the mixer 8 is used to mix the crude titanium tetrachloride filtrate output by the pre-membrane filtration unit 21 with mineral oil to obtain a mixed liquid; an evaporator 9, the evaporator 9 is used to evaporate the mixed liquid to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid; a distillation device 11, the distillation device 11 is used to distill the evaporation clear liquid to obtain a distillation gas and a distillation residue liquid, and the distillation residue liquid contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condensation device 13, the condensation device 13 is used to condense the distillation gas to obtain a refined titanium tetrachloride product.

[0072] 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 the 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 the first embodiment of the present disclosure introduces a pre-membrane filtration unit 21 of the refining unit as a key pretreatment link, thereby realizing high-efficiency liquid-solid separation membrane filtration treatment of the crude titanium tetrachloride in the traditional production process, thereby reducing the solid mass percentage content in the crude titanium tetrachloride filtrate input to the refining unit from the original 1%-2% to ≤0.1%, which helps to solve the key problems faced by the existing titanium tetrachloride refining system, such as unreasonable material circulation, improper slag liquid treatment, impurity circulation accumulation and prominent environmental pollution; this solution can significantly reduce the production of evaporated slag liquid and distilled slag liquid, reduce the liquid content of the concentrated liquid phase that needs to be returned to the chlorination furnace 1 and the impact on the thermal balance of the chlorination furnace, and at the same time reduce the discharge of waste liquid that needs to be neutralized with alkaline substances, thereby improving the comprehensive utilization rate and production efficiency of titanium tetrachloride resources and significantly reducing the risk of environmental pollution, and providing a simple and efficient improvement solution for the existing titanium tetrachloride production process.

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

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

[0076] More specifically, the post-solid-liquid separation membrane filtration unit 22 utilizes a terminal filter or a cross-flow filter. The filter element of the post-solid-liquid separation membrane filtration unit or the cross-flow filter is a porous material filter element with a filtration accuracy of 0.1 micron or less. Furthermore, the concentrated liquid from the post-solid-liquid separation membrane filtration unit 22 is returned to the solid-liquid separation unit via a reflux line.

[0077] The filter element of the terminal filter or cross-flow filter of the post-solid-liquid separation unit membrane filtration unit 22 is preferably an asymmetric porous material filter element, which filters through a surface filter layer. Preferably, the surface filter 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, significantly extending the filter element's service life. Furthermore, the asymmetric porous structure design provides the filter element with higher porosity and improved mechanical strength. When the surface filter layer is a sintered tantalum or niobium porous metal layer, filter element costs can be kept manageable.

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

[0080] The solid-liquid separation unit, comprising a sequentially connected coarse solid-liquid separation device 23 and a deliquating device 24, forms a cascade separation system, achieving advanced treatment of the slag-liquid phase. The coarse solid-liquid separation device 23 utilizes a settler, concentrator, or centrifuge to perform preliminary separation of the concentrated liquid, evaporated slag-liquid, and distilled slag-liquid phase, improving separation efficiency. Subsequently, the deliquating device 24 utilizes a press, filter press, or sealed evaporator to perform advanced deliquating treatment on the coarsely separated solid-liquid phase, significantly improving the recovery rate of titanium tetrachloride. Furthermore, the solid-liquid separation unit is capable of reducing the liquid content of the slag-liquid phase to ≤10% by mass, effectively resolving the limited initial deliquating effect of centrifuges 10 and 12 in the prior art.

[0081] Two separate solid-liquid separation devices 24 can be provided. One separate device simultaneously separates the concentrated liquid and the evaporation residue from the pre-membrane filtration unit 21 of the refining unit, while the other separates the distillation residue. The separate solid-liquid separation device has an insulated housing.

[0082] One of the coarse solid-liquid separation units specifically processes the concentrated liquid and evaporated residue from the pre-membrane filtration unit 21 of the refining unit, uniformly treating these two relatively low-temperature materials with similar properties to improve equipment utilization. The other coarse solid-liquid separation unit separately processes the distillation residue and is equipped with an insulated housing, effectively resolving the existing treatment difficulties caused by the presence of high-boiling-point impurities in the distillation residue relative to the boiling point of titanium tetrachloride. The insulated housing maintains the high temperature of the distillation residue, preventing the high-boiling-point impurities from cooling and solidifying, which could lead to decreased separation efficiency and equipment clogging. This improves the effective separation of vanadium and other chloride impurities, solves the problem of impurity circulation accumulation and the inability to effectively discharge vanadium and other chloride impurities from the system, and reduces the waste of valuable resources and the risk of valuable impurities such as vanadium generated during the refining process not being effectively recycled and utilized. This provides a more refined and resource-saving operation strategy for the titanium tetrachloride production system.

[0083] In addition, the solid-liquid separation unit may further include a slag-liquid phase collecting device 25 for collecting and storing the slag-liquid phase. The slag-liquid phase collecting device 25 can systematically collect the slag-liquid phase after being processed by the deliquating device 24, eliminating the need to return the slag-liquid phase to the chlorination furnace 1.

[0084] Figure 7 Schematic diagram of the titanium tetrachloride refining system of Example 2 of the present disclosure. Figure 7As shown, the titanium tetrachloride refining system of Example 2 of the present disclosure is improved on the basis of the titanium tetrachloride refining system of Example 1 above, and a sealed baking device 26 is provided after the solid-liquid separation unit. The sealed baking device 26 is used to perform a sealed baking treatment on the slag liquid phase to obtain titanium tetrachloride vapor and high-vanadium dry slag. The titanium tetrachloride vapor and the distillation 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 slag liquid output from the solid-liquid coarse separation device 23 to obtain a distilled gas phase and a distilled concentrated liquid. The distilled gas phase and the titanium tetrachloride vapor enter the condensation device 13 together for condensation treatment, and the distilled concentrated liquid enters the sealed baking device 26 for sealed baking treatment.

[0086] The titanium tetrachloride refining system of the second embodiment of the present 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 a thorough separation of titanium tetrachloride and impurities. The obtained titanium tetrachloride vapor directly enters the condensation device 13 for recovery, while the high-vanadium dry slag is retained as a valuable by-product; in addition, the distillation device 27 pre-treats the slag liquid output by the solid-liquid coarse separation device 23, separating it into a distillation gas phase and a distillation concentrate. The distillation gas phase and the titanium tetrachloride vapor enter the condensation device 13 together, and the distillation concentrate enters the sealed baking device 26 for deep treatment. This design completely solves the core problem of the failure of vanadium and other impurity chlorides in the prior art to effectively open the discharge system and waste valuable resources, realizes the efficient recovery of titanium tetrachloride and the effective extraction of vanadium resources, not only reduces the risk of environmental pollution, but also transforms the problem of irrational material circulation into the advantage of comprehensive resource utilization, significantly improves the economic benefits and environmental protection level of the titanium tetrachloride production system, and provides a comprehensive and systematic optimization solution for titanium tetrachloride refining technology.

[0087] As another implementation of the titanium tetrachloride refining system of Example 2 of the present disclosure, the post-membrane filtration unit 22 of the solid-liquid separation unit can also be eliminated, and the clear liquid phase output from the solid-liquid coarse separation device can be returned to the mixed liquid through the drainage pipe.

[0088] Figure 8 Schematic diagram of the titanium tetrachloride refining system of Example 3 of the present disclosure. Figure 8As shown, the titanium tetrachloride refining system of Example 3 of the present disclosure improves upon the titanium tetrachloride refining system of Example 2 above by adding a post-condensation membrane filtration unit 28. This post-condensation membrane filtration unit 28 is used to further filter the purified titanium tetrachloride product using a liquid-solid separation membrane, thereby ensuring that the solid content of the purified titanium tetrachloride product after the liquid-solid separation membrane filtration treatment does not exceed 0.01% by weight. Specifically, the post-condensation membrane filtration unit 28 can be an ultrafiltration device.

[0089] The third embodiment of the present disclosure, by adding a post-condensation membrane filtration unit 28 as a final product purification step, perfectly resolves the potential risks that may be caused by the installation of the distillation apparatus 27 and the sealed baking apparatus 26. Since the distilled gas phase generated by the distillation apparatus 27 and the titanium tetrachloride vapor released by the sealed baking apparatus 26 in the second embodiment both directly enter the condensation apparatus 13, although the titanium tetrachloride recovery rate is improved, trace amounts of impurity chloride particles such as vanadium may also be introduced, affecting the purity of the final product. The post-condensation membrane filtration unit 28, on the other hand, can use an ultrafiltration device to deeply purify the refined titanium tetrachloride product, ensuring that the solid content by weight does not exceed 0.01%. This achieves precise control of product quality and resolves the contradiction between irrational material circulation and high product quality faced by the titanium tetrachloride refining system. It maximizes the recovery of titanium tetrachloride resources while ensuring the ultra-high purity of the final product, effectively eliminating the risk of product quality fluctuations that may be caused by increasing the recovery rate.

[0090] The evaporator 9, distillation apparatus 11, and condensing apparatus 13 of the mineral oil refining unit in the above-mentioned embodiment are independent devices, which have the problems of large floor space, easy leakage of titanium tetrachloride during material transfer between devices, and high equipment investment costs. To this end, the following integrated evaporation, distillation, and condensation device for titanium tetrachloride refining is proposed. This integrated evaporation, distillation, and condensation device for titanium tetrachloride refining integrates the three functional units of evaporation, distillation, and condensation within the same tower, significantly reducing the floor space, eliminating the material transfer link between devices, significantly reducing the risk of titanium tetrachloride leakage, and effectively reducing equipment investment costs by sharing some structures and control systems, providing a safer, more economical, and more efficient technical solution for titanium tetrachloride refining systems.

[0091] Figure 9 This is a schematic diagram of an integrated evaporation, distillation and condensation device for refining titanium tetrachloride in Example 1. Figure 9 As shown, the integrated evaporation, distillation and condensation device for refining titanium tetrachloride includes a vertical outer cylinder 291 and a vertical inner cylinder 292 mounted in 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 external chamber forms a condensation chamber 29a, the lower part of the external chamber forms an evaporation chamber 29b, the upper part of the internal chamber forms a cooling chamber 29c, and the lower part of the internal 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, and 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 liquid outlet 298, an evaporation clear liquid guide channel 299 is provided between the evaporation chamber 29b and the distillation chamber 29d, and the distillation chamber 29d is provided with a distillation residue liquid outlet 2910.

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

[0095] The distillation chamber 29d is used to distill the evaporated clear liquid to obtain distillation gas and distillation residue liquid. The distillation residue liquid contains impurities with high boiling points relative to the boiling point of titanium tetrachloride. The distillation residue liquid is discharged from the distillation residue liquid outlet 2910. The distillation gas rises and enters the cooling chamber 29c for cooling and then enters the condensation chamber 29a.

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

[0097] The integrated evaporation, distillation, and condensation apparatus for titanium tetrachloride purification 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 leverages the natural process of material handling. Starting from evaporation chamber 29b, the evaporation and heating device 293 efficiently removes low-boiling-point impurities. The evaporated liquid enters the distillation chamber 29d through the evaporation liquid guide channel 299. The titanium tetrachloride vapor (distilled gas) is precisely separated by the distillation and heating device 294. The distilled gas naturally rises into the cooling chamber 29c, and is finally condensed and converted into the refined titanium tetrachloride product in the condensation chamber 29a. This vertically integrated configuration not only fundamentally solves the core problems of the large footprint of the evaporator 9, distillation unit 11 and condensing 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, greatly improving the safety, economy and energy efficiency of the system, and providing a new solution for titanium tetrachloride refining technology with a compact structure, optimized process and controllable risks.

[0098] Optionally, evaporation chamber 29b and / or distillation chamber 29d are equipped with an inert gas inlet 2911. By providing inert gas inlets 2911 in evaporation chamber 29b and / or distillation chamber 29d, the integrated device achieves precise atmosphere control in key reaction areas during the titanium tetrachloride refining process, effectively addressing the risk of titanium tetrachloride being oxidized and hydrolyzed by oxygen and moisture during high-temperature treatment. The introduction of inert gas not only removes residual reactive gases within the system but also creates a protective atmosphere, reducing the likelihood of titanium tetrachloride coming into contact with oxygen and moisture.

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

[0100] By adding a condensation chamber 29e below the outer chamber partition, this improved design creates a more refined material separation path. The vaporous phase produced by evaporation chamber 29b first enters condensation chamber 29e for initial condensation and separation, achieving efficient separation of low-boiling-point impurities from titanium tetrachloride. The interconnection between condensation chamber 29e and the upper portion of evaporation chamber 29b ensures that the vaporous phase produced during evaporation can flow naturally into the condensation area. A low-boiling-point impurity outlet 297 is located at the top of condensation chamber 29e, allowing low-boiling-point impurities to exit the system after the titanium tetrachloride vapor is fully condensed. Furthermore, condensation chamber 29e is connected to distillation chamber 29d via evaporation supernatant diversion channel 299, forming an "evaporation-condensation-distillation" process. This allows the condensed titanium tetrachloride-rich phase to flow into distillation chamber 29d for further purification. This improvement, by adding a dedicated condensation chamber 29e, improves the separation selectivity of low-boiling-point impurities and the recovery rate of titanium tetrachloride, further enhancing the separation accuracy and operational flexibility of the integrated device.

[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 variable diameter cylinder structure with an upper diameter expansion section and a lower diameter contraction section, which reflects the optimization of the geometric shape of the integrated device. This configuration enables the condensation chamber 29a to be located in the upper diameter expansion section, providing sufficient space for the condensation of gaseous substances, increasing the gas-liquid contact area and residence time, and improving the condensation efficiency; the evaporation chamber 29b is located in the lower diameter contraction section, forming a relatively concentrated hot zone, enhancing the heat transfer efficiency, and reducing the size and energy consumption of the evaporation heating device 293; the design of the condensation chamber 29e partially located in the upper diameter expansion section cleverly utilizes the space at the diameter change of the cylinder, creating more ideal conditions for the preliminary separation of low-boiling point impurities and titanium tetrachloride.

[0103] A first cooling structure can be provided in the condensation chamber 29e. A second cooling structure can be provided in the condensation chamber 29a. The first cooling structure provided in the condensation chamber 29e can effectively control the condensation rate and temperature gradient of the rising air flow in the evaporation chamber 29b, thereby achieving accurate separation of low-boiling-point impurities and titanium tetrachloride. The first cooling structure can be in the form of a coil, a cooling jacket or a plate heat exchanger (i.e. Figure 10The temperature of the cooling medium should be precisely controlled to be lower than the boiling point of the low-boiling impurities but slightly higher than the boiling point of titanium tetrachloride to ensure selective condensation. The second cooling structure provided in the condensation chamber 29a efficiently condenses the high-purity titanium tetrachloride vapor rising from the cooling chamber 29c. The 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 cooling chamber 29c, the cooling medium temperature should be below the freezing point of titanium tetrachloride to minimize clogging and maximize condensation efficiency. The temperature control systems of the first and second cooling structures can be adjusted independently, enabling 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, the evaporation chamber 29b, the cooling chamber 29c, the distillation chamber 29d, and the condensation chamber 29e to enable real-time monitoring of the process parameters of each functional area.

[0105] Figure 10 This is a schematic diagram of the integrated evaporation, distillation and condensation device for refining titanium tetrachloride in Example 2. Figure 10 As shown, the integrated evaporation, distillation and condensation device for refining titanium tetrachloride of Example 2 is improved on the basis of the integrated evaporation, distillation and condensation device for refining titanium tetrachloride of Example 1. After the improvement, an intermediate sleeve 2914 is further provided in the area below the partition in the external chamber, which is mounted 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 intermediate sleeve 2914 is added between the vertical outer cylinder 291 and the vertical inner cylinder 292, creating an innovative coaxially nested three-cylinder structure. This design precisely confines the evaporation chamber 29b to 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 "sleeve within a cylinder" structure significantly optimizes the heat and mass transfer paths and space utilization of the integrated device. This improvement allows the vaporized material produced by evaporation to flow from the evaporation chamber 29b to the condensation chamber 29e along a clear flow path, forming radial temperature and concentration gradients, and enhancing the separation of low-boiling-point impurities from titanium tetrachloride. Furthermore, the three-cylinder structure effectively isolates different temperature zones, reducing heat loss and improving energy efficiency. The intermediate sleeve 2914 also acts as a physical barrier to prevent direct mixing of materials in the evaporation and condensation zones, precisely controlling the residence time and flow direction of materials in each functional zone. 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 division.

[0107] Figure 11 This is a schematic diagram of the integrated evaporation, distillation and condensation device for refining titanium tetrachloride in Example 3. Figure 11 As shown, the integrated evaporation, distillation and condensation device for refining titanium tetrachloride in Example 3 includes a vertical cylinder 2915 and a condensation container 2916 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. The integrated evaporation and distillation chamber is provided with an evaporation heating device and a distillation heating device that work alternately.

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

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

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

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

[0113] Example 3 proposes a simplified integrated evaporation, distillation, and condensation apparatus for titanium tetrachloride purification. By designing the lower portion of a vertical cylinder 2915 as a combined evaporation and distillation chamber and the upper portion as a cooling chamber, connected to a condensation vessel 2916 to form a condensation chamber, an integrated "evaporation / distillation-cooling-condensation" vertical process is constructed. Its key innovation lies in the integration of the evaporation and distillation chambers. Alternating evaporation and distillation heating units enable sequentially separated operations within the same space: First, the evaporation chamber processes a mixture of crude titanium tetrachloride and mineral oil, removing low-boiling-point impurities and producing a clear evaporated liquid. Subsequently, the distillation chamber distills the clear evaporated liquid to remove high-boiling-point impurities. The resulting distilled gas enters the condensation chamber of condensation vessel 2916 via the cooling chamber to produce the refined titanium tetrachloride product. This design significantly simplifies the equipment structure and process flow, reduces the number of connecting components between mass and heat transfer units, and reduces equipment cost and floor space. Furthermore, the process is separated in time, rather than in space, eliminating intermediate material transfer steps and reducing energy and material losses. This device is particularly suitable for intermittent production mode and small- and 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 evaporation and distillation chamber is provided with an inert gas inlet. In addition, a cooling structure is provided in the condensate chamber. In addition, the condensation container 2916 is sleeved on the upper end of the vertical cylinder 2915.

[0115] Optionally, the vertical cylinder 2915 is a variable diameter cylinder having 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 cylinder, and the evaporation and distillation integrated chamber is located in the lower diameter contraction section of the variable diameter cylinder.

[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 the evaporation heating device is lower than the heating power of the heating device when used as the distillation heating device.

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

[0118] The titanium tetrachloride refining system of the fourth embodiment of the present disclosure is based on the titanium tetrachloride refining system of the first embodiment, and uses any one of the above-mentioned integrated evaporation, distillation and condensation devices for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0119] The titanium tetrachloride refining system of the fifth embodiment of the present disclosure is based on the titanium tetrachloride refining system of the second embodiment, and uses any one of the above-mentioned integrated evaporation, distillation and condensation devices for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0120] The titanium tetrachloride refining system of Example 6 of the present disclosure is based on the titanium tetrachloride refining system of Example 3, and uses any one of the above-mentioned integrated evaporation, distillation and condensation devices for titanium tetrachloride refining to replace the original evaporator 9, distillation device 11 and condensation device 13.

[0121] Figure 12 Schematic diagram of the titanium tetrachloride refining system of Example 7 of the present disclosure. Figure 12 As shown, the titanium tetrachloride refining system of Example 7 of the present disclosure includes a refining unit, which is a mineral oil refining unit, and the mineral oil refining unit includes: a mixer 8, wherein the mixer 8 is used to mix the crude titanium tetrachloride with mineral oil to obtain a mixed liquid; an evaporator 9, wherein the evaporator 9 is used to evaporate the mixed liquid to remove low-boiling-point impurities relative to the boiling point of titanium tetrachloride, and obtain an evaporation clear liquid and an evaporation residue liquid; a distillation device 11, wherein the distillation device 11 is used to distill the evaporation clear liquid to obtain a distillation gas and a distillation residue liquid, wherein the distillation residue liquid contains high-boiling-point impurities relative to the boiling point of titanium tetrachloride; a condensing device 13, wherein the condensing device 13 is used to condense the distillation gas to obtain a refined titanium tetrachloride product; a low-boiling-point impurity condenser 30, wherein the low-boiling-point impurity condenser 30 is used to recover the low-boiling-point impurities escaped 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 realizes the effective capture and resource utilization of low-boiling-point impurities (mainly silicon tetrachloride) escaping from the evaporator, condensing them into a liquid mixture rich in silicon tetrachloride, avoiding material loss and environmental pollution caused by the discharge of this part of the 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. It is enriched and converted into usable products through a special low-boiling-point impurity condenser, which greatly improves the economic benefits and resource utilization of the entire titanium tetrachloride production system.

[0123] Furthermore, the low boiling point impurity recovery system of the mineral oil refining unit has been further improved and optimized. Figure 12 As shown, the low-boiling-point impurities 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 to distill the liquid mixture, separating it into silicon tetrachloride vapor and a distillation bottoms liquid. The distillation bottoms liquid primarily contains titanium tetrachloride and a small amount of other impurities, while silicon tetrachloride, due to its lower 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 by-product.

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

[0126] Preferably, the silicon tetrachloride distiller 31 adopts a distillation tower structure equipped with a precise temperature control system. This system ensures that the temperature at the bottom of the distillation tower is maintained 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 within a range of 60°C-130°C. At the same time, the temperature at the top of the distillation tower is close to the boiling point of silicon tetrachloride and is precisely controlled within the range of 55°C-60°C. This temperature gradient design creates ideal separation conditions, allowing silicon tetrachloride to efficiently vaporize and rise to the top of the tower, while titanium tetrachloride remains in a liquid state and is discharged from the bottom of the tower.

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

[0128] The titanium tetrachloride refining system of Example 8 of this disclosure can be combined with the titanium tetrachloride refining systems of the other aforementioned examples to form a more comprehensive and efficient comprehensive refining solution. These combined implementations fully integrate the technical advantages of each example to construct a closed-loop, high-efficiency, and low-emission titanium tetrachloride refining system.

[0129] The above describes the relevant contents of the present disclosure. Based on these descriptions, a person of ordinary skill in the art will be able to implement the present disclosure. Based on the above contents of this specification, all other embodiments obtained by a person of ordinary skill in the art without making any creative efforts should fall within the scope of the present disclosure.

Claims

1. Titanium tetrachloride crude system, characterized by: include: A dust removal unit, which is used to efficiently collect dust from the titanium tetrachloride flue gas discharged from the chlorination furnace; as well as A cooling unit, which is used to cool the titanium tetrachloride flue gas after the high-efficiency dust collection treatment, collect the crude titanium tetrachloride product and discharge the tail gas with a temperature of ≤70°C; The dust removal efficiency of the dust removal unit is such that the solid mass percentage content of the crude titanium tetrachloride collected by the cooling unit is ≤0.1%; Furthermore, in the entire titanium tetrachloride flue gas flow path formed from the chlorination furnace to the cooling unit, the titanium tetrachloride flue gas does not pass through other cooling equipment except for natural cooling.

2. The crude titanium tetrachloride system according to claim 1, wherein: The dust removal unit comprises at least two stages of dust collectors, and at least the rear stage dust collector of the at least two stages of dust collectors adopts a flue gas precision filtration dust collector; The filter element of the flue gas precision filter dust collector can withstand the temperature of the titanium tetrachloride flue gas to be filtered and has chlorine corrosion resistance, and can also achieve the dust content of the filtered titanium tetrachloride flue gas ≤5mg / Nm 3 filtration efficiency.

3. The crude titanium tetrachloride system according to claim 2, wherein: The filter element of the flue gas precision filtering dust collector adopts a metal sintered filter element with Hastelloy C-276 as the main material.

4. The crude titanium tetrachloride system according to claim 3, wherein: The metal sintered filter element is surface treated by the following steps: Step 1: Performing electrochemical polishing on the surface of the main material to form an initial passivation layer that is rich in chromium and molybdenum and has a surface roughness Ra of 0.2 μm-0.3 μm; Step 2: performing anodizing treatment on the surface of the initial passivation layer to form an oxide layer with a thickness of 50 nm to 80 nm and mainly comprising Cr2O3, MoO3 and NiO; Step 3: performing a passivation treatment on the surface of the oxide layer to form a chromium-rich and molybdenum-rich stable passivation layer, wherein the passivation agent comprises a high-oxidation-state chromium salt, a molybdate and hydrofluoric acid.

5. The crude titanium tetrachloride system according to claim 2, wherein: The at least two-stage dust collector comprises a gravity dust collector, a cyclone dust collector and the flue gas precision filtration dust collector which are sequentially connected in front and back according to the flow path of the titanium tetrachloride flue gas; Alternatively, the at least two-stage dust collector comprises a gravity dust collector and the flue gas precision filtration dust collector connected in sequence along the flow path of the titanium tetrachloride flue gas; Alternatively, the at least two-stage dust collector comprises a cyclone dust collector and the flue gas precision filtering dust collector which are sequentially connected in front and back according to the flow path of the titanium tetrachloride flue gas.

6. The crude titanium tetrachloride system according to any one of claims 1 to 5, characterized in that: The cooling unit adopts a titanium tetrachloride flue gas condensation device; the titanium tetrachloride flue gas condensation device comprises: A condenser shell, wherein the side of the condenser shell is provided with a titanium tetrachloride flue gas inlet, the top is provided with an exhaust gas outlet, and the bottom is provided with a titanium tetrachloride crude product outlet; a partition-type heat exchange condensation component, which is arranged in the condenser shell and condenses the titanium tetrachloride flue gas into liquid through indirect heat exchange; a product tank connected to the crude titanium tetrachloride outlet and used to collect the titanium tetrachloride condensed into liquid; a cooling medium supply system, the cooling medium supply system being used to supply cooling medium to the partition-type heat exchange condensation component, the cooling medium transferring heat in the titanium tetrachloride flue gas to the cooling medium through the partition-type heat exchange condensation component; The regulating 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.

7. The crude titanium tetrachloride production system according to claim 6, wherein: The cooling medium is water, brine or refrigerant.

8. The crude titanium tetrachloride production system according to claim 7, wherein: The refrigerant is selected from at least one of ammonia (R717), R22, R32, R134a or R290 that complies with "ISO817:2014 Refrigerants - Name and Safety Classification Standard".

9. The crude titanium tetrachloride production system according to claim 6, wherein: There are at least two partition-type heat exchange condensation components which are arranged in sequence in the flow direction of the titanium tetrachloride flue gas. The cooling medium supply parameters between the partition-type heat exchange condensation components arranged in sequence are independently adjusted.

10. The crude titanium tetrachloride production system according to claim 6, wherein: It also includes a heat recovery device for recovering the heat energy taken out from the cooling medium and cooling the cooling medium for recycling; And / or, the partition-type heat exchange condensate component adopts tantalum fin heat exchange tubes or tantalum alloy fin heat exchange tubes.

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