Titanium chemical milling waste acid solution treatment equipment and process method

Abstract

The invention provides titanium chemical milling waste acid liquid treatment equipment and a process method, and belongs to the field of titanium chemical milling waste liquid treatment and recycling. The titanium chemical milling waste acid liquid treatment equipment comprises a filter, two pure acid boxes, a filter rod and a resin bed which are connected through a pipeline, and is provided with a valve, a pneumatic pump, an acid pump and a module control system; the module control system is used for controlling the titanium chemical milling waste acid solution to be sequentially filtered, backwashed, re-filtered, replaced, discharged and recycled, impurity ions are removed and nitric acid and hydrofluoric acid are recycled according to different speeds of components in the titanium chemical milling waste acid solution passing through a resin bed, and the module control system realizes automatic control by controlling a pneumatic pump, an acid pump and a pneumatic valve. The method provided by the invention can be used for recycling the waste acid at room temperature environment temperature, is simple and convenient in equipment operation and low in cost input, and is suitable for quickly removing titanium ions and the like in the titanium alloy chemical milling solution which takes a mixed solution of nitric acid, hydrofluoric acid, ethylene glycol monobutyl ether and lauryl sodium sulfate as a main component, and recycling nitric acid and hydrofluoric acid.

Description

Technical Field

[0001] This invention belongs to the field of titanium milling waste liquid treatment and recycling, and relates to a titanium milling waste acid liquid treatment equipment and process method, specifically to a device and process method for removing metallic titanium ions, aluminum ions, vanadium ions, etc. from titanium milling waste acid liquid and reusing nitric acid and hydrofluoric acid. Background Technology

[0002] In the aerospace field, titanium alloy chemical milling technology is widely used for the rapid machining of parts that are difficult to machine, especially suitable for the uniform milling removal of large, thin-plate parts. During chemical milling, hydrofluoric acid is continuously consumed, generating the soluble compound fluorotitanic acid. As the chemical milling process continues, the corrosion rate decreases as the concentration of free hydrofluoric acid decreases and the concentration of dissolved titanium ions increases. When the concentration of dissolved titanium ions reaches a certain level (exceeding 17 g / L), it adversely affects the processing quality of the solution. At this point, according to process requirements, the titanium chemical milling solution should be discarded and reconstituted. Based on production volume, a titanium ion concentration of 17 g / L can be reached quickly, resulting in a short discard cycle during production, averaging one tank of solution discarded per week. The discarding and reconstituted solutions lead to high production costs, significant safety risks throughout the process, and a large amount of hazardous strong acid waste, causing substantial environmental and social impact and severely affecting production efficiency. Therefore, there is an urgent need to develop equipment to remove titanium ions from titanium chemical milling solutions, enabling the removal of titanium and other metal ions while simultaneously recovering and reusing other components. Summary of the Invention

[0003] This invention provides a waste acid treatment device and process for titanium milling, used for removing impurities, water replacement, waste discharge, water replenishment, acid replacement, and acid recovery. The device can be used to reuse waste acid at room temperature. The device is simple and convenient to operate, with low cost. It is suitable for the rapid removal of titanium ions and other substances from titanium alloy milling solutions with a mixed solution of nitric acid, hydrofluoric acid, ethylene glycol monobutyl ether, and sodium dodecyl sulfate as the main components, as well as the reuse of nitric acid and hydrofluoric acid.

[0004] The technical solution adopted in this invention is as follows:

[0005] A waste acid treatment device for titanium milling includes a filter 7, two pure acid tanks, a filter rod 22, and a resin bed 23 connected by pipelines. It is equipped with valves, a pneumatic pump, an acid pump, and a modular control system 29. The modular control system 29 controls the waste acid from titanium milling to undergo sequential filtration, backwashing, refiltration, replacement, waste discharge, and recovery. Based on the different rates at which the components in the waste acid pass through the resin bed 23, impurity ions are removed and nitric acid and hydrofluoric acid are recovered. The modular control system 29 achieves automated control by controlling the pneumatic pump, acid pump, and pneumatic valves. Specifically:

[0006] The filter 7 is equipped with a filter element 15, the bottom of which is connected to the waste acid inlet 35 through a pipeline and connected to a first pneumatic pump 14. The top of the filter 7 is equipped with a first pneumatic valve 13. After the first pneumatic pump 14 is started, the first pneumatic valve 13 is opened. Through the pressure difference, the titanium milling waste acid liquid enters the filter 7 from the waste acid inlet 35 along the pipeline. The filter element 15 removes the suspended impurities in the titanium milling waste acid liquid. After filtration, the acid liquid flows out of the filter 7 through the top pipeline.

[0007] A hot water tank 1 is installed upstream of the filter 7. Tap water is introduced into the bottom of the hot water tank 1 through an inlet pipe. After being heated by the hot water tank 1, the water flows into the filter 7 through the outlet pipe at the top of the filter 7 to rinse the filter element 15 in the filter 7. The filter 7 is equipped with a pneumatic valve 12. When the pneumatic valve 12 is opened, hot water flows into the filter 7. At the same time, the top of the filter 7 is connected to a compressed air inlet 8 through a pipe to introduce compressed air to assist in rinsing the filter element 15. The impurities filtered out by the filter element 15 are discharged to the sewage treatment plant through a pipe equipped with a valve.

[0008] The two pure acid tanks are a first pure acid tank 33 and a second pure acid tank 32, respectively. The first pure acid tank 33 is located downstream of the filter 7, and the filtered acid solution flowing out of the filter 7 flows into the first pure acid tank 33. A pneumatic pressure regulating valve 17 is installed outside the first pure acid tank 33 and connected to a pneumatic pump 16. After the pneumatic pump 16 is started and the pneumatic pressure regulating valve 17 is opened, the acid solution flows out from the first pure acid tank 33. A radar level gauge 20 is installed on the top of the first pure acid tank 33 to monitor the level of the acid solution in the first pure acid tank 33 and prevent overflow. An emergency stop button is installed on the side wall of the first pure acid tank 33. In case of any abnormality in the pneumatic pump or valve, the emergency stop button can be activated immediately.

[0009] The filter rod 22 is located downstream of the first pure acid tank 33 and connected to the first pure acid tank 33. The downstream of the filter rod 22 is connected to the second pure acid tank 32 and connected to a third pneumatic pump 21. The acid flowing out of the first pure acid tank 33 is filtered again by the filter rod 22 and then powered by the third pneumatic pump 21 to flow into the second pure acid tank 32. Another radar level gauge 20 is installed on the top of the second pure acid tank 32 to monitor the level of the acid in the second pure acid tank 32 and prevent overflow.

[0010] The resin bed 23 is filled with resin. A second pneumatic valve 26, a waste discharge valve, and an acid valve are installed at the top of the resin bed 23. Its bottom is connected to a second pure acid tank 32 and is equipped with an acid pump 27. When the acid pump 27 is started and the second pneumatic valve 26 is opened, acid from the second pure acid tank 32 is fed into the resin bed 23 from the bottom. The resin-treated liquid flows out from the top of the resin bed 23. Downstream of the resin bed 23, it is connected to a water tank 25, a product discharge outlet 36, and a wastewater treatment station via pipelines. Simultaneously, the water tank 25 is connected to the bottom of the resin bed 23 via another pipeline and is equipped with a water valve for supplying water for rinsing the resin bed 23. The different components in the acid pass through the resin at different speeds; water displacement occurs first, and the water in the acid flows out of the resin after passing through it. The resin bed 23 enters the downstream water tank 25. After monitoring the time to confirm that all water has entered the water tank 25, the waste discharge valve is opened. The resin bed 23 discharges metal ion impurities from the acid solution. The metal ion impurities flow out of the resin bed 23 and enter the wastewater treatment station. After monitoring the time to confirm that all metal ion impurities have been discharged, the waste discharge valve is closed. The water valve is opened, and the acid solution adsorbed in the resin is flushed with water from the water tank 25 to perform acid replacement. The acid containing a small amount of metal ion impurities that is flushed out enters the second pure acid tank 32 through the acid solution valve. After the flushing time is completed, the acid solution valve is opened, and the resin is flushed with water. The flushed acid is returned to the production tank for reuse through the product discharge outlet 36 via the pipeline.

[0011] The module control system 29 monitors various instruments, including radar level gauge 20, pressure gauge 4, and temperature gauge 5, controls the opening and closing of various pneumatic pumps, acid pumps 27, and valves, as well as the opening time control, and monitors the flow of acid in various pipelines. Through system time control, it realizes automated control to achieve effective separation of various components in the acid, and ultimately achieves the discharge of metal ion impurities and the recovery of acid.

[0012] Furthermore, the water tank 25 is connected to the industrial water inlet 34 to replenish tap water, and another radar level gauge 20 is installed on its top for monitoring the liquid level.

[0013] Furthermore, the tops of both the second pure acid tank 32 and the first pure acid tank 33 are connected to the acid mist outlet 37 via pipelines to discharge the acidic gases volatilized inside them, thereby reducing the gas pressure inside the tanks.

[0014] Furthermore, the titanium milling waste acid treatment equipment also includes two dikes 30 and a back plate 31. The two dikes 30 are fixedly connected to the back plate 31. The filter 7, the first pure acid tank 33, the first pneumatic pump 14, the second pneumatic pump 16 and the pneumatic valve 12, the first pneumatic valve 13 and the pneumatic pressure regulating valve 17 installed on them are installed in one dike. The pure acid tank 2, the pneumatic pump 21, the filter rod 22, the resin bed 23, the water tank 25, the second pneumatic valve 26, the acid pump 27 and the module control box 29 are installed in the other dike. The dikes 30 are used to collect acid when acid leakage occurs to prevent acid leakage from causing environmental safety accidents.

[0015] Furthermore, the second pure acid tank 32 and the first pure acid tank 33 are made of PVDF material.

[0016] Furthermore, the first pneumatic pump 14, the second pneumatic pump 16, the third pneumatic pump 21, and the acid pump 27 are made of PVDF material.

[0017] Furthermore, all pipes, valves, as well as the dike 30, back plate 31, and water tank 25 in the titanium milling waste acid treatment equipment are made of PP material.

[0018] Furthermore, the hot water tank 1 is made of 304 stainless steel.

[0019] A process for treating waste acid from titanium milling, based on the aforementioned waste acid treatment equipment for titanium milling, includes the following steps:

[0020] Step 1, initial filtration. Controlled by the module control system 29, the waste acid solution from titanium milling is fed from the waste acid inlet 35 to the filter 7 by the first pneumatic pump 14 to remove suspended impurities from the waste acid solution. The filtered solution flows from the top of the filter 7 and is temporarily stored in the first pure acid tank 33.

[0021] Step 2, backwashing. Controlled by the module control system 29, the filter element 15 in the filter 7 is intermittently flushed using hot water from the hot water tank 1, and assisted by compressed air from the compressed air inlet 8. The flushing water enters the sewage treatment plant.

[0022] Step 3, further filtration. Controlled by the module control system 29, the acid solution in the first pure acid tank 33 is sent to the filter rod 22 for further filtration using the second pneumatic pump 16. The filtered acid solution is then sent to the second pure acid tank 32 by the third pneumatic pump 21.

[0023] Step 4, water replacement. Controlled by the module control system 29, the acid pump 27 is turned on to draw acid from the second pure acid tank 32 into the resin bed 23; water replacement is performed first, and the water in the acid first passes through the resin bed 23 into the water tank 25.

[0024] Step 5, waste discharge. The system time is monitored by the module control system 29. After the water replacement time is over, the waste discharge valve is opened, and metal ion impurities flow out through the resin bed 23 and enter the sewage treatment plant. The waste discharge valve is closed after the waste discharge time is over.

[0025] Step 6, acid replacement. Add tap water to water tank 25 for later use; the system time is monitored by module control system 29. After the waste discharge time is over, open the water valve at the bottom of water tank 25 to flush resin bed 23 for acid replacement, and flush the acid containing metal ion impurities into the second pure acid tank 32.

[0026] Step 7, acid recovery. The system time is monitored by the module control system 29. After the acid replacement time is over, the valve of the second pure acid tank 32 is closed, the acid valve is opened, and the resin bed 23 is rinsed with water. The acid adsorbed in the resin is recovered from the product outlet 36 and returned to the production tank. After the acid recovery time is over, the acid valve is closed.

[0027] The entire process is automated by the modular control system 29, which controls the time according to the process flow of each step and controls the operation of the entire equipment through the program, thus repeating the cycle repeatedly.

[0028] Furthermore, in step 1, when the titanium ion concentration in the waste acid solution of titanium milling reaches or approaches 17 g / L, it is treated as waste acid solution of titanium milling. In actual production, there are cases where waste treatment is required under other titanium ion concentration conditions. This process method is also applicable, but the recovery efficiency will be appropriately reduced.

[0029] The beneficial effects of this invention are:

[0030] This invention employs an integrated design encompassing filtration, backwashing, refiltration, displacement, waste discharge, and recovery. Based on the varying rates at which different components pass through the resin bed and utilizing time constraints, it removes impurities such as titanium and vanadium ions from the solution, while recovering and reusing nitric acid and hydrofluoric acid. Compared to traditional impurity ion sedimentation separation methods, this equipment generates no solid waste during acid reuse. The removed titanium and vanadium ions are discharged in liquid form, which can be discharged along with wastewater generated during production. The collected wastewater is then treated as acid-base water. Minimal maintenance and cleaning are required during operation. After introducing the filtered waste solution from the titanium-based milling process into the equipment, by controlling the running time of each step, titanium and vanadium ions can be separated from the solution. The titanium ion removal rate can reach 60%-80%, and the recovery rate of nitric acid and hydrofluoric acid exceeds 85%. The reaction can be carried out at ambient temperature, making operation simple, convenient, and cost-effective. Attached Figure Description

[0031] Figure 1This is a schematic diagram of the structure of a titanium-based milling waste acid treatment equipment.

[0032] In the diagram: 1. Hot water tank; 2. Flange; 3. Safety valve; 4. Pressure gauge; 5. Thermometer; 6. Safety valve; 7. Filter; 8. Compressed air inlet; 9. Pressure valve; 10. Manual ball valve; 11. Pneumatic three-way valve; 12. Pneumatic valve; 13. First pneumatic valve; 14. First pneumatic pump; 15. Filter element; 16. Second pneumatic pump; 17. Pneumatic pressure regulating valve; 18. First swivel joint; 19. Second swivel joint; 20. Radar level gauge; 21. Third pneumatic pump; 22. Filter rod; 23. Resin bed; 24. Bolt; 25. Water tank; 26. Second pneumatic valve; 27. Acid pump; 28. Plug cap; 29. ​​Module control system; 30. Dike; 31. Backplate; 32. Second pure acid tank; 33. First pure acid tank; 34. Industrial water inlet; 35. Waste acid inlet; 36. Product outlet; 37. Acid mist outlet. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings.

[0034] A waste acid treatment device for titanium milling includes a filter 7, two pure acid tanks, a filter rod 22, and a resin bed 23 connected by pipelines. It is equipped with valves, a pneumatic pump, an acid pump, and a modular control system 29. The device sequentially filters, backwashes, re-filters, replaces, discharges, and recovers the waste acid from titanium milling. Based on the different rates at which the components in the waste acid pass through the resin bed 23, it removes impurity ions and recovers nitric acid and hydrofluoric acid. The modular control system 29 achieves automated control by controlling the pneumatic pump, acid pump, and pneumatic valves. Figure 1 As shown. Specifically:

[0035] The filter 7 is cylindrical in shape, with a diameter of 250mm and a height of 800mm. Both the top and bottom ends are sealed with 12 bolts to a 400mm diameter cap with a sealing ring. Five pneumatic pipes are evenly distributed on the top cap, each equipped with a first pneumatic valve 13. The filter 7 contains a filter element 15, the bottom of which is connected to a waste acid inlet 35 via a pipe and connected to a first pneumatic pump 14. The filter 7 has a first pneumatic valve 13 on top. When the first pneumatic pump 14 is started, the first pneumatic valve 13 opens, allowing the titanium milling waste acid to enter the filter 7 through the waste acid inlet 35 via the pipe due to pressure difference. The filter element 15 removes suspended impurities from the titanium milling waste acid, and the filtered acid flows out of the filter 7 through the top pipe. The filter 7 is equipped with a pressure valve 9, a manual ball valve 10, and a pneumatic three-way valve 11 to regulate the opening degree of the first pneumatic valve 13 and balance the air pressure inside the filter 7.

[0036] A hot water tank 1 is installed upstream of the filter 7. The hot water tank 1 is cylindrical with a diameter of 600mm and a height of 1000mm. It is equipped with an electric heating rod with a temperature setting range of 50-60℃. The material is 304 stainless steel, and it is formed by roll forming and finally welded. Tap water is introduced into the bottom through the inlet pipe. Hot water at 50-60℃ is prepared in the hot water tank 1 and flows into the filter 7 through the outlet pipe at the top to flush the filter element 15 and ensure the efficient operation of the filter 7. The filter 7 is equipped with a pneumatic valve 12. When the pneumatic valve 12 is opened, hot water flows into the filter 7. The outlet pipe of the hot water tank 1 is a PP pipe. Safety valves 3 are installed on both the inlet and outlet pipes to control the water flow. Pressure gauge 4, thermometer 5 and safety valve 6 are installed outside the hot water tank 1 for the regulation and monitoring of the hot water tank 1. The temperature control and water supply of the hot water tank 1 are automatically controlled by the module control system 29. At the same time, the top of the filter 7 is connected to the compressed air inlet 8 through a pipe to introduce compressed air to assist in rinsing the filter element 15. The impurities filtered out by the filter element 15 are discharged to the sewage treatment plant through a pipe equipped with a valve.

[0037] The first pure acid tank 33 is located downstream of the filter 7. The filtered acid solution flowing out of the filter 7 flows into the first pure acid tank 33. The first pure acid tank 33 has dimensions of 300×240×1000mm and a lid to prevent splashing of the solution entering the tank. Two pipes are provided on the side wall of the first pure acid tank 33, corresponding to the low and high liquid levels of the first pure acid tank 33, for acid outflow. A pneumatic pressure regulating valve 17 is installed outside the first pure acid tank 33 and connected to a pneumatic pump 16. After the pneumatic pump 16 is started and the pneumatic pressure regulating valve 17 is opened, the acid solution flows out from the first pure acid tank 33. A radar level gauge 20 is installed on the top of the first pure acid tank 33 to monitor the liquid level of the filtered acid solution in the first pure acid tank 33 and prevent overflow of acid at high liquid levels. An emergency stop button is installed on the side wall of the first pure acid tank 33. In case of any abnormality in the pneumatic pump or valve, the emergency stop button can be activated immediately.

[0038] The filter rod 22 is located downstream of the first pure acid tank 33 and is connected to two pipes on the side wall of the first pure acid tank 33 via a first swivel joint 18 and a second swivel joint 19, respectively. The downstream end of the filter rod 22 is connected to the second pure acid tank 32 and is also connected to a third pneumatic pump 21. The acid flowing from the first pure acid tank 33 is filtered again by the filter rod 22 and then propelled by the third pneumatic pump 21 into the second pure acid tank 32. Another radar level gauge 20 is installed on the top of the second pure acid tank 32 to monitor the acid level and prevent overflow. The second pure acid tank 32 has dimensions of 300×200×950mm and a lid with a small opening for observation. The tops of both the second pure acid tank 32 and the first pure acid tank 33 are connected to an acid mist outlet 37 via pipes to discharge the acidic gases volatilized inside, thereby reducing the internal pressure.

[0039] The resin bed 23 is a cylindrical tube that is narrow in the middle and wide at both ends. The diameter at both ends is 560mm, and the smallest diameter at the middle is 400mm, with a smooth curve transition. Its height is 650mm. The end caps are secured with 16 bolts 24, and each cap has a sealing ring. The cylindrical tube is filled with resin. A second pneumatic valve 26, a waste discharge valve, and an acid valve are installed at the top of the resin bed 23. Its bottom is connected to a second pure acid tank 32 via pipeline and is equipped with an acid pump 27. Starting the acid pump 27 and opening the second pneumatic valve 26 allows acid from the second pure acid tank 32 to be fed into the resin bed 23 from the bottom. The resin-treated liquid flows out from the top of the resin bed 23. Downstream of the resin bed 23, pipelines connect it to a water tank 25, a product discharge outlet 36, and a wastewater treatment station. The water tank 25 is also connected to the bottom of the resin bed 23 via a separate pipeline and is equipped with a water valve for rinsing the resin bed 23. Water; the different components in the acid solution pass through the resin at different speeds. The first step is water replacement. After the water in the acid solution passes through the resin, it flows out of the resin bed 23 and into the water tank 25 located downstream. After monitoring the time to confirm that all the water has entered the water tank 25, the waste discharge valve is opened. The resin bed 23 discharges metal ion impurities from the acid solution. The metal ion impurities flow out of the resin bed 23 and enter the wastewater treatment station. After monitoring the time to confirm that all metal ion impurities have been discharged, the waste discharge valve is closed. The water valve is opened, and the acid solution adsorbed in the resin is rinsed with water from the water tank 25 to perform acid replacement. The acid containing a small amount of metal ion impurities that is rinsed out enters the second pure acid tank 32 through the acid solution valve. After the rinsing time is completed, the acid solution valve is opened, and the resin is rinsed with water to recover the acid. The rinsed acid is returned to the production tank for reuse through the product discharge outlet 36 via a pipeline.

[0040] The module control system 29 monitors various instruments, including radar level gauge 20, pressure gauge 4, and temperature gauge 5, controls the opening and closing of various pneumatic pumps, acid pumps 27, and valves, as well as the opening time control, and monitors the flow of acid in various pipelines. Through system time control, it realizes automated control to achieve effective separation of various components in the acid, and ultimately achieves the discharge of metal ion impurities and the recovery of acid. The criteria for determining whether the water in the resin bed 23 has been completely drained are: observing the color of the pipes; the pipes are transparent when water passes through, and if the pipe color darkens, it indicates that the water has been drained and the waste discharge stage has begun. This process is initially observed manually and the time is recorded to determine the water draining duration, which is then entered into the control program of the module control system 29. The criteria for determining the end of waste discharge of metal ion impurities are: checking whether the pipe color has become transparent and whether the pipe has a temperature. Because acid and water mix, heat is released; therefore, if the pipe is transparent and hot, waste discharge is complete. This process is initially observed manually and the time is recorded to determine the waste discharge completion duration, which is then entered into the control program of the module control system 29. The process for determining the complete removal of metal ion impurities from the acid solution is also initially observed manually and the time is recorded, and then entered into the control program of the module control system 29. Finally, the process for determining whether acid recovery has ended is by observing the pipe temperature; if the pipe temperature no longer increases, acid recovery is complete. This process is initially observed manually and the time is recorded to determine the water draining duration, which is then entered into the control program of the module control system 29.

[0041] The water tank 25 is connected to the industrial water inlet 34 to replenish tap water, and another radar level gauge 20 is installed on its top to monitor the liquid level.

[0042] The titanium-milling waste acid treatment equipment also includes two dikes 30 and a back plate 31. The two dikes 30 are fixedly connected to the back plate 31. The filter 7, the first pure acid tank 33, the first pneumatic pump 14, the second pneumatic pump 16 and the pneumatic valve 12, the first pneumatic valve 13 and the pneumatic pressure regulating valve 17 installed on them are installed in one dike. The pure acid tank 2, the pneumatic pump 21, the filter rod 22, the resin bed 23, the water tank 25, the second pneumatic valve 26, the acid pump 27 and the module control box 29 are installed in the other dike. The dikes 30 are used to collect acid when acid leakage occurs to prevent acid leakage from causing environmental safety accidents.

[0043] In the titanium-milling waste acid treatment equipment, each pipeline port can be sealed with a plug cap 28.

[0044] The second pure acid tank 32 and the first pure acid tank 33 are made of PVDF material.

[0045] The first pneumatic pump 14, the second pneumatic pump 16, the third pneumatic pump 21, and the acid pump 27 are made of PVDF material.

[0046] All pipes, valves, as well as the dike 30, back plate 31, and water tank 25 in the titanium milling waste acid treatment equipment are made of PP material.

[0047] A process for treating waste acid from titanium milling, based on the aforementioned waste acid treatment equipment for titanium milling, includes the following steps:

[0048] Step 1, Initial Filtration. The waste acid from titanium milling contains a large amount of impurities, giving the solution a distinct blue-green color. When the titanium ion concentration in the solution reaches or approaches 17 g / L, it is treated as waste acid from titanium milling. The waste acid is pumped from the waste acid inlet 35 to the filter 7 via the first pneumatic pump 14 to remove suspended impurities. The filtered solution flows from the top of the filter 7 and is temporarily stored in the first pure acid tank 33. In actual production, there are situations where waste treatment is required under other titanium ion concentration conditions; this process is also applicable, although the recovery efficiency will be appropriately reduced.

[0049] Step 2, backwashing. The module control system 29 controls the hot water in the hot water tank 1 at 50℃-60℃ to intermittently rinse the filter element 15 in the filter 7, and the compressed air inlet 8 assists in the rinsing to effectively prevent the filter element 15 from clogging and to prevent it from affecting the filtration effect of the filter element 15 on the waste tank liquid. The rinsing water enters the sewage treatment plant.

[0050] Step 3, further filtration. The module control system 29 controls the second pneumatic pump 16 to filter the acid in the first pure acid tank 33 through the filter rod 22 to further remove suspended metal compound impurities in the acid. The filtered acid is clear and blue-green, and then enters the second pure acid tank 32 through the pipeline via the third pneumatic pump 21.

[0051] Step 4, water replacement. The module control system 29 controls the acid pump 27 to draw acid from the second pure acid tank 32 into the resin bed 23; because water molecules are small, they pass through the resin bed faster, and the water in the acid first passes through the resin bed 23 into the water tank 25.

[0052] Step 5, waste discharge. The module control system 29 monitors the system time until the water replacement is completed, then opens the waste discharge valve. Metal ion impurities flow out through the resin bed 23 and enter the wastewater treatment plant. The module control system 29 immediately closes the waste discharge valve when the system time is up.

[0053] Step 6, acid replacement. Add tap water to water tank 25 for later use; after waste discharge, the module control system 29 controls the opening of the water valve at the bottom of water tank 25 to flush resin bed 23, and flush the resin bed 23 containing metal ion impurities into the second pure acid tank 32.

[0054] Step 7, acid recovery. The module control system 29 monitors the system time and closes the valve of the second pure acid tank 32, opens the acid valve and continues to rinse the resin bed 23 with water to backwash the nitric acid and hydrofluoric acid adsorbed in the resin. The rinsed acid solution is recovered from the product outlet 36 and enters the production tank. The module control system 29 monitors the system time until the acid valve is closed.

[0055] The entire process is automated by the module control system 29, which controls the time according to the process flow of each step and controls the operation of the entire equipment through the program, thus repeating the cycle.

[0056] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A waste acid treatment device for titanium-based milling processes, characterized in that, It includes a filter (7) connected by pipelines, two pure acid tanks, filter rods (22), and resin bed (23), and is equipped with valves, pneumatic pumps, acid pumps and a modular control system (29). The modular control system (29) controls the titanium milling waste acid liquid to be filtered, backwashed, re-filtered, replaced, discharged and recycled in sequence. According to the different speeds of the components in the titanium milling waste acid liquid through the resin bed (23), impurity ions are removed and nitric acid and hydrofluoric acid are recovered. The modular control system (29) realizes automatic control by controlling the pneumatic pump, acid pump and pneumatic valve.

2. The titanium-based milling waste acid treatment equipment according to claim 1, characterized in that, Specifically, it includes: The filter (7) is equipped with a filter element (15). The waste acid liquid of titanium milling is introduced from the bottom of the filter through a pipe and connected to a first pneumatic pump (14). The top of the filter (7) is equipped with a first pneumatic valve (13). The waste acid liquid of titanium milling is introduced into the filter (7) through the pressure difference. After the impurities are removed by the filter element (15), it flows out of the filter (7). A hot water tank (1) is installed upstream of the filter (7). The hot water tank (1) is heated by the tap water pipe and flows into the filter (7) to rinse the filter element (15). The rinsed solution is discharged to the sewage treatment station. The two pure acid tanks are a first pure acid tank (33) and a second pure acid tank (32); the first pure acid tank (33) is located downstream of the filter (7), and the acid liquid flowing out of the filter (7) flows into the first pure acid tank (33); a pneumatic pressure regulating valve (17) is provided outside the first pure acid tank (33) and connected to a pneumatic pump (16) to control the acid liquid flowing out of the first pure acid tank (33); The filter rod (22) is located downstream of the first pure acid tank (33) and connected to it. The downstream of the filter rod (22) is connected to the second pure acid tank (32) and connected to a third pneumatic pump (21). The acid liquid flowing out from the first pure acid tank (33) is filtered again by the filter rod (22) and then sent into the second pure acid tank (32) by the third pneumatic pump (21). The resin bed (23) is filled with resin. A second pneumatic valve (26), a waste discharge valve, and an acid valve are installed on the top of the resin bed (23). Its bottom is connected to a second pure acid tank (32) and is equipped with an acid pump (27) to send the acid from the second pure acid tank (32) into the resin bed (23) from the bottom. The liquid treated by the resin flows out from the top of the resin bed (23). The downstream of the resin bed (23) is connected to a water tank (25), a product outlet (36), and a sewage treatment station through pipelines. At the same time, the water tank (25) is equipped with a separate... The pipeline is connected to the bottom of the resin bed (23) to supply water for rinsing the resin bed (23); according to the different speeds of the components in the acid solution through the resin, the components are separated by controlling the time and related valves. The water flows out of the resin bed (23) and into the water tank (25), while the metal ion impurities flow out of the resin bed (23) and into the sewage treatment station. The resin is rinsed with water from the water tank (25), so that the acid solution containing metal ion impurities enters the second pure acid tank (32), and then the acid is returned from the product discharge port (36) to the production tank for reuse. The module control system (29) controls the opening and closing of each pneumatic pump, acid pump (27), and valve, as well as the opening time control, and monitors the flow of acid in each pipeline. Through system time control, it realizes automated control to achieve effective separation of each component in the acid.

3. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, The top of the filter (7) is also connected to the compressed air inlet (8) via a pipe for introducing compressed air to assist in rinsing the filter element (15).

4. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, Radar level gauges (20) are installed on the top of both the first pure acid tank (33) and the second pure acid tank (32) to monitor the liquid level and prevent overflow.

5. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, An emergency stop button is installed on the side wall of the first pure acid tank (33) for emergency use in case of abnormal situations.

6. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, The water tank (25) is connected to the industrial water inlet (34) to replenish tap water.

7. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, The tops of the second pure acid tank (32) and the first pure acid tank (33) are connected to the acid mist outlet 37 via pipelines to discharge the acidic gases volatilized inside them.

8. The titanium-based milling waste acid treatment equipment according to claim 2, characterized in that, The titanium milling waste acid treatment equipment also includes two dikes (30) and a back plate (31). The two dikes (30) are fixedly connected to the back plate (31). The filter (7), the first pure acid tank (33), the first pneumatic pump (14), the second pneumatic pump (16), the first pneumatic valve (13), and the pneumatic pressure regulating valve (17) are installed in one dike. The pure acid tank 2, the pneumatic pump 21, the filter rod (22), the resin bed (23), the water tank (25), the second pneumatic valve (26), the acid pump (27), and the module control box 29 are installed in the other dike. The dike (30) is used to collect acid when acid leakage occurs.

9. A process for treating waste acid from titanium milling, implemented based on the waste acid treatment equipment for titanium milling as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1, initial filtration; controlled by the module control system (29), the waste acid liquid of titanium milling is sent from the waste acid inlet (35) to the filter (7) by the first pneumatic pump (14) to remove the suspended impurities in the waste acid liquid of titanium milling. The filtered solution flows from the top of the filter (7) and is temporarily stored in the first pure acid tank (33). Step 2, backwashing; controlled by the module control system (29), the hot water in the hot water tank (1) is used to intermittently rinse the filter element (15) in the filter (7), and the rinse water enters the sewage treatment station; Step 3, further filtration; controlled by the module control system (29), the acid in the first pure acid tank (33) is sent to the filter rod (22) for further filtration by the second pneumatic pump (16), and the filtered acid is sent to the second pure acid tank (32) by the third pneumatic pump (21). Step 4, water replacement; controlled by the module control system (29), the acid pump (27) is turned on to draw the acid from the second pure acid tank (32) into the resin bed (23); water replacement is performed first, and the water in the acid first passes through the resin bed (23) into the water tank (25); Step 5, waste discharge; The system time is monitored by the module control system (29). After the water replacement time is over, the waste discharge valve is opened, and metal ion impurities flow out through the resin bed (23) and enter the sewage treatment station. When the waste discharge time is over, the waste discharge valve is closed. Step 6, acid replacement; The system time is monitored by the module control system (29). After the waste discharge time is over, the resin bed (23) is rinsed with water in the water tank (25) to perform acid replacement, and the acid containing metal ion impurities is rinsed into the second pure acid tank (32). Step 7, acid recovery; The system time is monitored by the module control system (29). After the acid replacement time is over, the acid valve is opened and the resin bed (23) is rinsed with water. The acid adsorbed in the resin is recovered from the product outlet (36) and returned to the production tank. After the acid recovery time is over, the acid valve is closed. The entire process is automated by a modular control system (29).

10. The process for treating waste acid from titanium milling according to claim 9, characterized in that, In step 1, titanium ion concentration in the waste acid solution of titanium milling reaches or approaches 17 g / L and is treated as waste acid solution of titanium milling. Waste acid solutions of titanium milling with other titanium ion concentrations can also be treated.

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