Accurate distillation production process for titanium sponge

Abstract

The invention relates to the technical field of titanium metal smelting, in particular to a precise sponge titanium distillation production process which comprises the following steps: after the sealing performance of an assembled reactor is qualified, heating the first to fourth areas of a distillation furnace to 1000-1050 DEG C; a vacuum unit composed of a roots pump and an oil diffusion pump is opened, the vacuum degree is accurately controlled in the 15th hour, the 30th hour, the 45th hour, the 60th hour, the 75th hour, the 90th hour and the 105th hour in the distillation process, the corresponding vacuum degree ranges are 3000-3500Pa, 1000-1200Pa, 400-450Pa, 50-80Pa, 30-50Pa, 10-15Pa and 3-7Pa in sequence, the vacuum degree is monitored 1h in advance in each stage, and the vacuum degree is maintained by adjusting the rotating speed through a variable frequency motor or starting a standby pump for combined air exhaust; after distillation is finished, an inert gas circulating cooling system is adopted for cooling, and the cooling rate is smaller than or equal to 10 DEG C / min. According to the process, the vacuum degree and the temperature are precisely regulated and controlled in stages, impurities in the sponge titanium can be effectively removed, the product purity is improved, meanwhile, it is guaranteed that the production process is stable and controllable, and the production efficiency and the product quality consistency are improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of titanium metal smelting, in particular to a sponge titanium precision distillation production process. BACKGROUND

[0002] Sponge titanium is widely used in the fields of aerospace, shipbuilding, metallurgy, chemical industry, automobile and energy due to its small density, high specific hardness, excellent high and low temperature resistance and corrosion resistance. Sponge titanium is an important raw material for preparing titanium materials and other titanium components. At present, the commercial production of sponge titanium at home and abroad adopts the method of magnesium reduction of titanium tetrachloride, which mainly includes three processes of magnesium reduction of titanium tetrachloride, vacuum distillation of the reduction product and product crushing.

[0003] The reduction and distillation processes are the core processes of sponge titanium production and the key links for determining the quality of sponge titanium products. The vacuum distillation process is directly affected by chlorine elements. At present, the distillation process only focuses on the final vacuum degree and ignores the distillation process, which may lead to batch instability.

[0004] Publication No. CN117443004A discloses a sponge titanium distillation furnace condenser temperature control device and method, which provides reliable reference data for the cooling intensity of the condenser cooling water, solves the problem of distillation channel blockage in the distillation process caused by insufficient cooling intensity of the condenser, and accurately controls the spray water flow to realize smooth distillation.

[0005] The above-mentioned comparative document relates to the field of sponge titanium distillation, but has many obvious defects:

[0006] (1) In terms of temperature control, it only focuses on the temperature of the condenser. By setting a temperature measuring device on the outer wall of the condenser, the cooling intensity of the cooling water is adjusted according to the measured temperature to control the wall temperature, so as to avoid distillation channel blockage and magnesium and chloride vapor escaping to the vacuum system. However, this method ignores the important influence of the overall temperature of the distillation furnace on the distillation process. Sponge titanium distillation is a complex process, and the temperature of different regions of the distillation furnace needs to be accurately controlled to ensure stable and efficient distillation reaction and product quality. However, the comparative document does not mention the temperature control of other parts of the distillation furnace except the condenser, which has a serious deficiency in the comprehensiveness of temperature control.

[0007] (2) From the perspective of vacuum control, the comparison file does not involve this key factor at all. In the process of titanium sponge distillation, vacuum degree plays a crucial role in distillation efficiency and product purity. Different stages of distillation require precise control of vacuum degree to meet the reaction requirements. For example, as the distillation time advances, the appropriate vacuum degree range at different stages differs greatly. For example, a higher vacuum degree may be needed in the early stage of distillation to facilitate the initial separation of the material, and further adjustment is needed in the later stage to achieve more refined purification. However, due to the lack of vacuum control-related content in the comparison file, the vacuum environment cannot be effectively adjusted according to the distillation process, which greatly limits its application in actual production and makes it difficult to ensure the accuracy of the distillation process and the stability of the product quality.

[0008] (3) In terms of the overall production process integrity, the comparison file has obvious shortcomings. It only focuses on the temperature control of the condenser tank, and does not involve other essential aspects of titanium sponge distillation production, such as the heating process of the distillation furnace and the cooling process after distillation. A complete titanium sponge distillation production process, from the early equipment preparation, heating, to the temperature and vacuum degree control during the distillation process, and then to the cooling process, each link is closely connected and interacts. The lack of consideration of other key links makes this technical solution unable to form a complete and systematic production process, making it difficult to be independently applied in actual production and unable to provide comprehensive and effective technical guidance for titanium sponge production enterprises. SUMMARY

[0009] The purpose of the present application is to provide a precise titanium sponge distillation production process to solve the problem of batch instability caused by the lack of attention to the distillation process in the existing titanium sponge production distillation.

[0010] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0011] A precise titanium sponge distillation production process, comprising the following steps:

[0012] (1) After the assembled reactor passes the sealing test, the distillation furnace is heated from top to bottom into 1, 2, 3, and 4 zones, and the temperature is raised to the specified temperature;

[0013] (2) After the vacuum unit is turned on, the distillation is carried out for 15 hours. The vacuum unit consists of a Roots pump and an oil diffusion pump. The speed is adjusted by a frequency conversion motor to control the vacuum degree to the specified requirement. The vacuum degree is closely monitored 1 hour in advance. If the specified vacuum degree A cannot be reached, increase the speed or start the standby pump for joint pumping. If the specified vacuum degree is exceeded, reduce the speed;

[0014] (3) After opening the vacuum unit, distill the 30th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree B cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0015] (4) After opening the vacuum unit, distill the 45th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree C cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0016] (5) After opening the vacuum unit, distill the 60th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree D cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0017] (6) After opening the vacuum unit, distill the 75th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree E cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0018] (7) After opening the vacuum unit, distill the 90th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree F cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0019] (8) After opening the vacuum unit, distill the 105th hour, control the vacuum degree to the specified requirement, start to pay close attention to the vacuum degree 1 hour in advance, if the specified vacuum degree G cannot be reached, increase the rotating speed or start the standby pump joint pumping, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0020] (9) After the distillation is completed, switch to cooling, and the inert gas circulating cooling system is used in the cooling stage, and the cooling rate is ≤10℃ / min.

[0021] Preferably, in step (1), the temperatures of the distillation furnace 1, 2, 3 and 4 are all 1000-1050℃.

[0022] Preferably, in step (2), the vacuum degree A is controlled to be 3000-3500Pa.

[0023] Preferably, in step (3), the vacuum degree B is controlled to be 1000-1200Pa, and B / A is 0.28-0.4.

[0024] Preferably, in step (4), the vacuum degree C is controlled to be 400-450Pa, and C / B is 0.30-0.45.

[0025] As preferred, in step (5), the control range of the vacuum degree D is 50-80 Pa, and D / C is 0.1-0.2.

[0026] As preferred, in step (6), the control range of the vacuum degree E is 30-50 Pa, and E / D is 0.37-1.00.

[0027] As preferred, in step (7), the control range of the vacuum degree F is 10-15 Pa, and F / E is 0.2-0.5.

[0028] As preferred, in step (8), the control range of the vacuum degree G is 3-7 Pa, and G / F is 0.2-0.7.

[0029] As preferred, in steps (2) to (8), the adjustment mode of the vacuum degree is: when the vacuum degree cannot reach the specified requirement, the speed is increased or the standby pump is started to jointly pump; when the vacuum degree exceeds the specified requirement, the speed is reduced.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] The sponge titanium precision distillation production process provided by the present application has the beneficial effects of scientific process control, product quality improvement, and production stability optimization, which can be described in detail from multiple dimensions, as follows:

[0032] I. Precise matching of distillation thermodynamic properties to improve impurity removal efficiency and completeness

[0033] The core of sponge titanium distillation is to remove the impurities (mainly magnesium chloride, excess magnesium and other trace metal compounds) remaining from the reduction reaction through a high-temperature vacuum environment, and the vapor pressures of different impurities vary significantly with time and temperature. The present application realizes efficient removal of impurities through the following design:

[0034] Gradient vacuum degree control: gradually reduced from 3000-3500 Pa at 15 h to 3-7 Pa at 105 h, forming a highly matched vacuum environment with the volatilization characteristics of impurities. For example, during the initial stage of distillation (15-30 h), magnesium chloride and excess magnesium are in a high-vapor-pressure state, and a higher vacuum degree (3000-3500 Pa→1000-1200 Pa) can accelerate their volatilization from the surface and shallow layer of the titanium ingot; as the distillation proceeds (after 45 h), the impurities gradually diffuse to the deep layer of the titanium ingot, at which time the vacuum degree is gradually reduced (400-450 Pa→3-7 Pa), which can drive the deep-layer impurities to volatilize through a larger pressure difference, avoiding the problem of "complete surface impurity removal but residual in the center" in traditional processes.

[0035] Partition temperature control coordination: The distillation furnace 1-4 zones maintain a high temperature of 1000-1050℃, ensuring the formation of a uniform and stable thermal field in the furnace, making the temperature of the titanium slug consistent in each region, avoiding the difficulty of removing impurities due to insufficient vapor pressure caused by local low temperature, or the side reactions of titanium material oxidation and nitridation caused by local high temperature.

[0036] Second, real-time dynamic control mechanism to ensure process stability and controllability

[0037] The traditional process only focuses on the vacuum degree at the end of distillation, ignoring the impact of process fluctuations on product quality. The present invention realizes whole-process controllability through the mechanism of "early warning + precise intervention":

[0038] Node monitoring and adjustment: 1 hour before the 7 key time nodes (15h, 30h…105h), the vacuum degree is closely monitored, and real-time intervention is carried out for cases deviating from the specified range (such as increasing the speed or starting the standby pump when the target value is not reached, or reducing the speed when it exceeds). This design can effectively avoid the vacuum degree fluctuations caused by sudden factors such as vacuum system leakage and pump body efficiency decline, ensuring that the impurity removal in each stage is in the best pressure environment, avoiding the "chain reaction" caused by abnormal vacuum degree in a certain stage (such as low initial vacuum degree leading to slow impurity volatilization, which requires longer time to make up, thereby increasing energy consumption).

[0039] Dual-pump linkage adjustment: Through the dual means of "main pump speed regulation + standby pump joint vacuum pumping", the vacuum degree deviation can be quickly responded. For example, when the vacuum degree is not within the range of 1000-1200 Pa at 30h of distillation, starting the standby pump can pull the vacuum degree to the target range within 1h, avoiding the recondensation of impurities inside the titanium slug due to the continuous high pressure, ensuring the continuity of the removal efficiency.

[0040] Three, reduce batch-to-batch variability and improve product quality stability

[0041] The batch stability of sponge titanium directly affects the performance consistency of subsequent titanium material processing (such as forging and rolling). However, due to the extensive process control, the traditional process often has large differences in chlorine content, hardness, and impurity distribution between batches. The present invention solves this problem in the following ways:

[0042] Standardized process parameters: The vacuum degree range (A-G) and the mutual proportion relationship (such as B / A=0.28-0.4, C / B=0.30-0.45, etc.) of each time node are clearly specified, and the partition temperature control (1000-1050℃) is unified, making the distillation environment of each batch highly consistent. This standardized control can eliminate human operational differences (such as the experience-dependent adjustment of vacuum degree in the traditional process), ensuring that the impurity removal path of different batches of titanium slug is the same.

[0043] Adapt to the structure characteristics of titanium slug: Titanium slug forms a porous structure during reduction, and there are differences in impurity distribution and volatilization resistance between the core and the surface layer. The gradient vacuum degree design of the present application exactly adapts to this characteristic - the initial higher vacuum degree preferentially removes the easily volatile impurities on the surface layer, and the later low vacuum degree specifically removes the impurities with larger diffusion resistance in the core, so that the overall impurity distribution of the titanium slug is uniform, the local quality defects such as "the surface layer is qualified but the chlorine content in the core exceeds the standard" in the traditional process are avoided, and the performance fluctuation between batches (such as the chlorine content standard deviation can be controlled within 0.005%, which is much lower than the 0.02% of the traditional process) is reduced.

[0044] Four, optimize production efficiency, reduce energy consumption and cost

[0045] Scientificity of fixed distillation time: the total distillation time is controlled within 105h, and the accurate control of each stage ensures that the complete removal is completed within this time, avoiding the "blindly prolonging the distillation time" caused by process out of control in the traditional process (such as some batches need more than 120h), and improving the equipment turnover rate.

[0046] Precise control of energy consumption: the energy consumption of the vacuum system is directly related to the pump body speed and running time. The present application avoids the energy waste of "high speed vacuum pumping all the way" in the traditional process through the method of "adjusting the speed as needed + standby pump linkage". For example, only a low vacuum degree of 3-7Pa is needed in the later stage of distillation (90-105h), at this time, reducing the speed of the main pump can meet the demand, which can reduce the energy consumption by 20%-30% compared with high speed running all the way.

[0047] Five, enhance the process adaptability and reduce the production risk

[0048] In industrial production, problems such as fluctuation of raw material purity and slight leakage of equipment are difficult to completely avoid, and the control mechanism of the present application has strong anti-interference ability:

[0049] Early warning mechanism: closely monitor the vacuum degree 1h before each key node, which can find potential abnormalities (such as the rising trend of vacuum degree caused by the decrease of pump efficiency) in advance, and take measures (such as adjusting the speed in advance) in time to avoid the problem from getting worse.

[0050] Flexible adjustment means: the combination of "adjusting the speed + standby pump joint pumping" can cope with different degrees of vacuum deviation. For example, slight deviation can be corrected by adjusting the speed, and when the deviation is serious, the standby pump can be started to quickly restore the pressure, ensuring that the process stability is maintained even in the case of local equipment failure, and reducing the loss caused by shutdown for repair.

[0051] In summary, the present application optimizes the sponge titanium distillation process from the aspects of impurity removal efficiency, product quality stability, production economy, etc. through the synergistic design of "partition temperature control + gradient vacuum degree + nodal dynamic regulation", and is especially suitable for the fields such as aerospace which have extremely high requirements for sponge titanium purity (such as chlorine content <0.05%) and batch consistency, and has significant technical progress and industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0052] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and together with the embodiments of the present application, make further detailed explanation, but do not constitute a limitation on the present application.

[0053] Figure 1 The flow chart of the present application sponge titanium precise distillation production process. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0055] Embodiment 1

[0056] (1) After the sealing of the assembled reactor is qualified, the distillation furnace is heated, and the distillation furnace is divided into 1, 2, 3, 4 zones from top to bottom, and is heated to 1000℃;

[0057] (2) After the vacuum unit is opened, the distillation is carried out for the 15th hour, the vacuum degree is controlled to 3000Pa, and the vacuum degree is closely observed 1h in advance. If the specified vacuum degree cannot be reached, the speed is increased or the standby pump is started to jointly extract. If the specified vacuum degree is exceeded, the speed is reduced;

[0058] (3) After the vacuum unit is opened, the distillation is carried out for the 30th hour, the vacuum degree is controlled to 1000Pa, and the vacuum degree is closely observed 1h in advance. If the specified vacuum degree cannot be reached, the speed is increased or the standby pump is started to jointly extract. If the specified vacuum degree is exceeded, the speed is reduced;

[0059] (4) After the vacuum unit is opened, the distillation is carried out for the 45th hour, the vacuum degree is controlled to 400Pa, and the vacuum degree is closely observed 1h in advance. If the specified vacuum degree cannot be reached, the speed is increased or the standby pump is started to jointly extract. If the specified vacuum degree is exceeded, the speed is reduced;

[0060] (5) After the vacuum unit is opened, distill for the 60th hour, control the vacuum degree to 50 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0061] (6) After the vacuum unit is opened, distill for the 75th hour, control the vacuum degree to 30 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0062] (7) After the vacuum unit is opened, distill for the 90th hour, control the vacuum degree to 10 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0063] (8) After the vacuum unit is opened, distill for the 105th hour, control the vacuum degree to 3 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0064] (9) Distillation is completed, and cooling is performed.

[0065] Example 2

[0066] (1) After the assembled reactor passes the sealing test, the distillation furnace is heated, and the distillation furnace is divided into 1, 2, 3 and 4 from top to bottom, and is heated to 1000℃;

[0067] (2) After the vacuum unit is opened, distill for the 15th hour, control the vacuum degree to 3300 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0068] (3) After the vacuum unit is opened, distill for the 30th hour, control the vacuum degree to 1100 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0069] (4) After the vacuum unit is opened, distill for the 45th hour, control the vacuum degree to 425 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0070] (5) After the vacuum unit is opened, distill for the 60th hour, control the vacuum degree to 70 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0071] (6) After the vacuum unit is opened, distill for the 75th hour, control the vacuum degree to 40 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0072] (7) After the vacuum unit is opened, distill for the 90th hour, control the vacuum degree to 13 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0073] (8) After the vacuum unit is opened, distill for the 105th hour, control the vacuum degree to 5 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0074] (9) Distillation is completed, and cooling is performed.

[0075] Example 3

[0076] (1) After the assembled reactor passes the sealing test, the distillation furnace is heated, the distillation furnace is divided into 1, 2, 3 and 4 zones from top to bottom, and is heated to 1000 DEG C;

[0077] (2) After the vacuum unit is opened, distill for the 15th hour, control the vacuum degree to 3000-3500 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0078] (3) After the vacuum unit is opened, distill for the 30th hour, control the vacuum degree to 1000-1200 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0079] (4) After the vacuum unit is opened, distill for the 45th hour, control the vacuum degree to 400-450 Pa, start to closely monitor the vacuum degree 1 hour in advance, if the specified vacuum degree cannot be reached, increase the rotating speed or start the standby pump to jointly pump, if the specified vacuum degree is exceeded, reduce the rotating speed;

[0080] (5) After opening the vacuum unit, distill for 60h, control the vacuum degree to 50-80Pa, start to pay close attention to the vacuum degree 1h in advance, if unable to reach the specified vacuum degree, increase the rotating speed or start the standby pump joint pumping, if exceed the specified vacuum degree, reduce the rotating speed;

[0081] (6) After opening the vacuum unit, distill for 75h, control the vacuum degree to 30-50Pa, start to pay close attention to the vacuum degree 1h in advance, if unable to reach the specified vacuum degree, increase the rotating speed or start the standby pump joint pumping, if exceed the specified vacuum degree, reduce the rotating speed;

[0082] (7) After opening the vacuum unit, distill for 90h, control the vacuum degree to 10-15Pa, start to pay close attention to the vacuum degree 1h in advance, if unable to reach the specified vacuum degree, increase the rotating speed or start the standby pump joint pumping, if exceed the specified vacuum degree, reduce the rotating speed;

[0083] (8) After opening the vacuum unit, distill for 105h, control the vacuum degree to 3-7Pa, start to pay close attention to the vacuum degree 1h in advance, if unable to reach the specified vacuum degree, increase the rotating speed or start the standby pump joint pumping, if exceed the specified vacuum degree, reduce the rotating speed;

[0084] (9) Distillation is completed, turn to cooling.

[0085] Comparative Example 1 (non- segmented temperature control and vacuum degree)

[0086] (1) After the assembled reactor passed the sealing test, the distillation furnace was heated, the distillation furnace was not divided into zones for temperature control, and the whole was heated to 900℃;

[0087] (2) After opening the vacuum unit, only pay attention to the vacuum degree 1h before the end of the distillation, control the final vacuum degree to 5Pa, and the vacuum degree at key nodes such as 15h and 30h is not controlled, the vacuum degree changes naturally;

[0088] (3) After 105h of distillation, the distillation was completed and turned to cooling.

[0089] Comparative Example 2 (fixed vacuum degree without dynamic adjustment)

[0090] (1) After the assembled reactor passed the sealing test, the distillation furnace was heated, the distillation furnace was divided into 1, 2, 3 and 4 zones from top to bottom, and was heated to 1000-1050℃;

[0091] (2) After opening the vacuum unit, the vacuum degree was kept fixed at 500Pa throughout the process, without adjusting at nodes such as 15h (3000-3500Pa) and 30h (1000-1200Pa), only simply adjusting the rotating speed when the vacuum degree deviated from 500Pa, without setting standby pump joint pumping;

[0092] (3) Distillation is ended after 105 h and is transferred to cooling.

[0093] The above three examples of key parameters and results comparison table:

[0094]

[0095] From the above comparison of key data of the examples and comparative examples, 1. Temperature control difference

[0096] Examples 1-3: Using zoning temperature control (1000-1050℃), by precise control of temperature in different areas, to provide stable thermal field for magnesium reduction and distillation process, which is beneficial to TiCl4 reduction and MgCl2 efficient separation.

[0097] Comparative example 1: The overall temperature is controlled to 900℃, which is low and has no regional gradient, which may lead to incomplete reduction reaction (such as TiCl4 residual) or incomplete MgCl2 vaporization, affecting the purity of titanium sponge.

[0098] 2. Vacuum degree regulation mechanism

[0099] Examples 1-3:

[0100] Segmented gradient control: gradually reduce the vacuum degree (3000 Pa→3 Pa) with the progress of distillation, which conforms to the physical properties of MgCl2 vapor pressure changing with temperature, ensuring the maximum efficiency of impurity removal at each stage.

[0101] Dynamic adjustment: predict the change of vacuum degree 1 h in advance, adjust the speed or use the standby pump to jointly evacuate, to avoid the influence of vacuum degree fluctuation on product quality.

[0102] Comparative example 2: The vacuum degree is fixed at 500 Pa throughout the process, which cannot match the best thermodynamic conditions at each stage of distillation. For example:

[0103] Initial stage (15 h): too high vacuum degree may lead to rapid vaporization of MgCl2, forming a surface crust to hinder the overflow of internal impurities;

[0104] Later stage (after 60 h): insufficient vacuum degree makes it difficult to remove low-vapor-pressure impurities (such as NaCl), reducing product purity.

[0105] 3. Comparison of vacuum degree at key nodes

[0106]

[0107] 4. Influence of adjustment method on stability

[0108] Examples: Through the "prediction + dual pump linkage" mechanism, the vacuum degree fluctuation is controlled within ±5%, ensuring the repeatability of the distillation process (such as impurity content RSD <3% between batches).

[0109] Comparative Example 1: Without node regulation, natural change of vacuum degree leads to unstable impurity removal, and local overheating (such as "hot spot" leading to TiC generation) or incomplete removal area may occur.

[0110] Comparative Example 2: Single pump simple regulation response lag, vacuum degree fluctuation can reach ±20%, easy to cause "boil-condense" cycle, pollute the condensing system and reduce production efficiency.

[0111] 5. Comprehensive performance prediction

[0112]

[0113] Conclusion

[0114] The present application is significantly superior to the traditional process in the following aspects through the synergistic effect of partition temperature control + segmented gradient vacuum degree + dynamic regulation:

[0115] Impurity removal efficiency: Gradient vacuum degree matches distillation kinetics, making MgCl2 and metal impurity removal more thorough;

[0116] Product stability: Dynamic regulation mechanism reduces vacuum degree fluctuation, ensuring batch-to-batch performance consistency;

[0117] Energy efficiency optimization: Precise control avoids excessive vacuum pumping, reducing energy consumption by about 15-20% (compared to fixed high vacuum process).

[0118] Comparative Examples 1 and 2 lack key control elements, with obvious defects in purity, stability or cost, confirming the creativity and industrial application value of the present application.

[0119] The sponge titanium precise distillation production process provided by the present application has beneficial effects that can be elaborated in detail from the scientific nature of process control, product quality improvement, and production stability optimization, etc., as follows:

[0120] I. Precise matching of distillation thermodynamic properties to improve impurity removal efficiency and thoroughness

[0121] The core of sponge titanium distillation is to remove impurities (mainly magnesium chloride, excess magnesium and other trace metal compounds) remaining from the reduction reaction through a high-temperature vacuum environment, and the vapor pressure of different impurities varies significantly with time and temperature. The present application achieves efficient impurity removal through the following design:

[0122] Gradient vacuum control: gradually reduce the vacuum degree from 3000-3500 Pa at the beginning of distillation (15-30 h) to 3-7 Pa at the end of distillation (105 h), forming a vacuum environment that matches the volatility characteristics of impurities. For example, at the beginning of distillation (15-30 h), magnesium chloride and excess magnesium are in a high-vapor-pressure state, and a higher vacuum degree (3000-3500 Pa→1000-1200 Pa) can accelerate their evaporation from the surface and shallow layer of the titanium ingot. As the distillation progresses (after 45 h), impurities gradually diffuse to the deep layer of the titanium ingot, and at this time, gradually reducing the vacuum degree (400-450 Pa→3-7 Pa) can drive the deep-layer impurities to evaporate through a larger pressure difference, avoiding the problem of "complete removal of surface impurities but residual in the core" in traditional processes.

[0123] Zoning temperature control coordination: all zones 1-4 of the distillation furnace are maintained at a high temperature of 1000-1050°C, ensuring the formation of a uniform and stable thermal field in the furnace, making the temperature of each region of the titanium ingot consistent, and avoiding the problems of insufficient vapor pressure of impurities due to local low temperature, making it difficult to remove, or local high temperature causing side reactions such as oxidation and nitridation of titanium materials.

[0124] II. Real-time dynamic control mechanism to ensure process stability and controllability

[0125] Traditional processes only focus on the vacuum degree at the end of distillation, ignoring the impact of process fluctuations on product quality. The present invention realizes whole-process controllability through the mechanism of "early warning + precise intervention":

[0126] Node monitoring and adjustment: 1 hour before each of the 7 key time nodes (15h, 30h…105h), the vacuum degree is closely monitored, and real-time intervention is performed for cases that deviate from the specified range (such as increasing the speed or starting the standby pump when the target value is not reached, or reducing the speed when it exceeds). This design can effectively avoid the vacuum degree fluctuations caused by sudden factors such as vacuum system leakage and pump body efficiency decline, ensuring that the impurity removal in each stage is in the best pressure environment, and avoiding the "chain reaction" caused by abnormal vacuum degree in a certain stage (such as slow impurity evaporation due to low initial vacuum degree, which requires longer time to compensate, increasing energy consumption).

[0127] Dual-pump linkage adjustment: through the dual means of "main pump speed adjustment + standby pump joint vacuum pumping", the vacuum degree deviation can be quickly responded. For example, when the vacuum degree is not within the range of 1000-1200 Pa at 30 h of distillation, starting the standby pump can pull the vacuum degree to the target range within 1 h, avoiding the recondensation of impurities inside the titanium ingot due to the continuous high pressure, and ensuring the continuity of the removal efficiency.

[0128] III. Reduce batch-to-batch variability and improve product quality stability

[0129] Batch stability of sponge titanium directly affects the performance consistency of subsequent titanium material processing (such as forging and rolling), and the traditional process often has large differences in chlorine content, hardness and impurity distribution between batches due to extensive process control. The invention solves this problem in the following way:

[0130] Standardized process parameters: clearly specify the vacuum degree range (A-G) and the mutual proportion relationship (such as B / A=0.28-0.4, C / B=0.30-0.45, etc.) at each time node, and unify the partition temperature control (1000-1050℃), so that the distillation environment of each batch is highly consistent. This standardized control can eliminate human operation differences (such as the experience dependence of vacuum degree adjustment in traditional process), and ensure that the impurity removal path of different batches of titanium is the same.

[0131] Adapt to the structural characteristics of titanium: the titanium forms a porous structure during reduction, and there are differences in impurity distribution and volatilization resistance between the core and the surface. The gradient vacuum degree design of the invention exactly adapts to this characteristic - the initial higher vacuum degree preferentially removes the easily volatile impurities on the surface, and the later low vacuum degree specifically removes the impurities with larger diffusion resistance in the core, making the overall impurity distribution of the titanium uniform, avoiding the local quality defects in the traditional process such as "surface qualified but core chlorine content exceeding standard", and thus reducing the performance fluctuation between batches (such as the chlorine content standard deviation can be controlled within 0.005%, which is much lower than the 0.02% of the traditional process).

[0132] Four, optimize production efficiency, reduce energy consumption and cost

[0133] Scientificity of fixed distillation time: the total distillation time is controlled within 105h, and through accurate control of each stage, it is ensured that complete removal is completed within this time, avoiding the "blindly extending the distillation time" caused by process out of control in the traditional process (such as some batches need more than 120h), and improving the equipment turnover rate.

[0134] Precise control of energy consumption: the energy consumption of the vacuum system is directly related to the pump body speed and running time. The invention avoids the energy waste of "full-speed vacuum pumping" in the traditional process through "adjusting the speed as needed + standby pump linkage". For example, during the later stage of distillation (90-105h), only a low vacuum degree of 3-7Pa is needed, at this time, reducing the speed of the main pump can meet the demand, which can reduce energy consumption by 20%-30% compared with full-speed operation.

[0135] Five, enhance process adaptability and reduce production risk

[0136] In industrial production, problems such as fluctuation of raw material purity and small leakage of equipment are difficult to completely avoid, and the control mechanism of the invention has strong anti-interference ability:

[0137] Early warning mechanism: 1h in advance before each key node closely monitor the vacuum degree, can be found in advance potential anomalies (such as the vacuum degree rising trend caused by pump body efficiency decline), and take timely measures (such as advance to adjust the speed), to avoid the problem of expansion.

[0138] Flexible adjustment means: "combined way of adjusting speed + standby pump joint pumping", can deal with different degrees of vacuum deviation. For example, slight deviation can be corrected by adjusting the speed, and when the deviation is serious, the standby pump can be started to quickly restore the pressure, ensuring that even in the case of partial failure of the equipment, the process stability can still be maintained, reducing the loss caused by shutdown for maintenance.

[0139] In summary, the present application optimizes the sponge titanium distillation process from the aspects of impurity removal efficiency, product quality stability, production economy, etc. through the synergistic design of "partition temperature control + gradient vacuum degree + node dynamic regulation", especially suitable for aerospace and other fields with extremely high requirements for sponge titanium purity (such as chlorine content <0.05%) and batch consistency, with significant technical progress and industrial application value.

[0140] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A precision distillation process for producing sponge titanium, characterized in that: Includes the following steps: (1) After the assembled reactor is sealed, the distillation furnace is heated. The distillation furnace is divided into zones 1, 2, 3 and 4 from top to bottom, and the temperature is raised to the specified temperature. (2) After the vacuum unit is turned on, distillation is carried out for 15 hours. The vacuum unit includes a combination of Roots pump and oil diffusion pump. The speed is adjusted by the variable frequency motor to control the vacuum degree to the specified requirement. The vacuum degree is closely monitored 1 hour in advance. If the specified vacuum degree A cannot be reached, the speed is increased or the standby pump is started to pump together. If the specified vacuum degree is exceeded, the speed is reduced. (3) After turning on the vacuum unit, control the vacuum level to the specified requirement on the 30th hour of distillation. Start monitoring the vacuum level closely 1 hour in advance. If the specified vacuum level B cannot be reached, increase the speed or start the standby pump for joint pumping. If the specified vacuum level is exceeded, reduce the speed. (4) After turning on the vacuum unit, distill for 45 hours and control the vacuum degree to the specified requirement. Start monitoring the vacuum degree closely 1 hour in advance. If the specified vacuum degree C cannot be reached, increase the speed or start the standby pump for joint pumping. If the specified vacuum degree is exceeded, reduce the speed. (5) After turning on the vacuum unit, distill for 60 hours and control the vacuum level to the specified requirement. Start monitoring the vacuum level closely 1 hour in advance. If the specified vacuum level D cannot be reached, increase the speed or start the standby pump for combined pumping. If the specified vacuum level is exceeded, reduce the speed. (6) After turning on the vacuum unit, distill for 75 hours and control the vacuum level to the specified requirement. Start monitoring the vacuum level closely 1 hour in advance. If the specified vacuum level E cannot be reached, increase the speed or start the standby pump for combined pumping. If the specified vacuum level is exceeded, reduce the speed. (7) After turning on the vacuum unit, distill for 90 hours and control the vacuum degree to the specified requirement. Start monitoring the vacuum degree closely 1 hour in advance. If the specified vacuum degree F cannot be reached, increase the speed or start the standby pump for joint pumping. If the specified vacuum degree is exceeded, reduce the speed. (8) After turning on the vacuum unit, distill for 105 hours and control the vacuum level to the specified requirement. Start monitoring the vacuum level closely 1 hour in advance. If the specified vacuum level G cannot be reached, increase the speed or start the standby pump for combined pumping. If the specified vacuum level is exceeded, reduce the speed. (9) After distillation, the process is transferred to cooling. The cooling stage uses an inert gas circulating cooling system with a cooling rate of ≤10℃ / min.

2. The precision distillation production process for sponge titanium according to claim 1, characterized in that: In step (1), the temperature of zones 1, 2, 3 and 4 of the distillation furnace is 1000-1050℃.

3. The precision distillation process for producing sponge titanium according to claim 1, characterized in that: In step (2), the vacuum degree A is controlled at 3000-3500 Pa.

4. The precision distillation process for producing sponge titanium according to claim 1, characterized in that: In step (3), the vacuum degree B is controlled within the range of 1000-1200 Pa, and the B / A ratio is between 0.28 and 0.

4.

5. The precision distillation production process for sponge titanium according to claim 1, characterized in that: In step (4), the vacuum degree C is controlled within the range of 400-450 Pa, and the C / B ratio is between 0.30 and 0.

45.

6. The precision distillation production process for sponge titanium according to claim 1, characterized in that: In step (5), the vacuum degree D is controlled within the range of 50-80 Pa, and the D / C ratio is between 0.1 and 0.

2.

7. The precision distillation process for producing sponge titanium according to claim 1, characterized in that: In step (6), the vacuum degree E is controlled within the range of 30-50 Pa, and the E / D ratio is between 0.37 and 1.

00.

8. The precision distillation process for producing sponge titanium according to claim 1, characterized in that: In step (7), the vacuum degree F is controlled within the range of 10-15 Pa, and the F / E ratio is between 0.2 and 0.

5.

9. The precision distillation production process for sponge titanium according to claim 1, characterized in that: In step (8), the vacuum degree G is controlled within the range of 3-7 Pa, and the G / F ratio is between 0.2 and 0.

7.

10. The precision distillation process for producing sponge titanium according to claim 1, characterized in that: In steps (2) to (8), the vacuum level is adjusted as follows: when the vacuum level cannot meet the specified requirements, the rotation speed is increased or the standby pump is started to pump in conjunction; when the vacuum level exceeds the specified requirements, the rotation speed is reduced.

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