A method for continuous acidolysis of titanium concentrate and a pre-mixing system of mineral acid used

Abstract

The application is a kind of titanium concentrate continuous acidolysis method and the ore acid premixing system used. The ore powder metering bin, weighing device and control device in the metering bin are set to accurately control the amount of ore powder entering the metering bin; when the amount is too much, the feeding is stopped; and when the standard value is reached, the ore powder in the metering bin is introduced into the premixing device and sulfuric acid for premixing; and through the spraying mode, it enters the premixing screw feeder for sufficient mixing; by adding sulfuric acid with appropriate concentration in the premixing process and cooling water in the cooling bin to control the temperature in the premixing screw feeder at 34-36 degrees, the early reaction is prevented; and through the reaction monitoring device to monitor whether the reaction is carried out, through the valve on the water baffle to add water to reduce the concentration of sulfuric acid and continue to control the temperature when the reaction occurs; double action prevents the reaction; at the same time, after feeding, it is cleaned by countercurrent water.

Description

Technical Field

[0001] The invention relates to the technical field of titanium concentrate acid decomposition, and in particular to a titanium concentrate continuous acid decomposition method and a mineral acid premixing system used therein. Background Art

[0002] Titanium concentrate is mined from ilmenite or titanomagnetite and is the raw material for producing titanium dioxide, which has a very wide range of uses. Acid decomposition of titanium concentrate is an important production link of sulfuric acid method titanium dioxide. The efficiency of its acid decomposition determines the efficiency of its acid decomposition material. The invention patent with application number CN202111628397.5 discloses a high-impurity titanium concentrate acid decomposition process. It obtains acid decomposition material by premixing and acid decomposition. Compressed air is added for stirring during the acid decomposition process to improve the efficiency of acid decomposition. However, the titanium concentrate acid decomposition process in the prior art is mostly an intermittent acid decomposition process. That is, the feeding of the acid decomposition reaction in the acid decomposition reactor is not continuous, but intermittent. Although this feeding method can be effective, The invention patent with publication number CN114084903A discloses a method for continuous acid hydrolysis of titanium concentrate; by reacting heated dilute sulfuric acid with an acid-ore mixture and controlling the heating temperature of the dilute sulfuric acid, the temperature of the continuous acid hydrolysis reaction system can be stably controlled; by introducing dilute sulfuric acid, the consumption of concentrated sulfuric acid in the continuous acid hydrolysis process can be significantly reduced under the same reaction acid-ore ratio conditions; although dilute sulfuric acid is introduced to solve the problems of temperature control and concentrated sulfuric acid consumption in the acid hydrolysis reaction; the dilute sulfuric acid will result in insufficient sulfuric acid concentration during the reaction, which will slow down the reaction and the purity of the acid hydrolyzate finally formed is not enough.

[0003] (1) Technical problems solved

[0004] In order to solve the above technical problems, the present invention provides a method for continuous acid hydrolysis of titanium concentrate and a mineral acid premixing system used therein.

[0005] (2) Technical solution

[0006] A titanium concentrate continuous acid hydrolysis and acid premixing system comprises a ore powder screening and processing bin, a conveying device, a ore powder metering bin, a ore powder sulfuric acid premixer, a premixing screw feeder, a feeding pipe, and an acid hydrolysis reaction bin.

[0007] Furthermore, a ore powder screening net and a ore powder magnetic separation device are provided in the ore powder screening processing bin; the ore powder screening net is provided above the ore powder magnetic separation device.

[0008] Furthermore, a conveying device is provided in the mineral powder screening and processing bin and the mineral powder metering bin and the two bins are connected; the conveying device adopts a closed conveying system; the conveying system is provided with a connecting valve I at both ends connected to the mineral powder screening and processing bin and the mineral powder metering bin; a weight sensor and an automatic calibration system as well as a controller I and a data storage system are provided in the mineral powder metering bin; the amount of titanium concentrate powder required in the mineral powder and sulfuric acid premixing bin is input into the data storage system.

[0009] Furthermore, one end of the conveying device extending into the mineral powder metering bin is arranged above the weight sensor and conveys the screened mineral powder to the weight sensor.

[0010] Furthermore, the bottom weight sensor of the mineral powder metering bin is connected to the automatic calibration system; the weight sensor is electrically connected to the controller; the controller I is connected to the data storage system; a mineral powder guide pipe is provided at the bottom of the weight sensor; the lower part of the mineral powder guide pipe passes through the mineral powder metering bin and a connecting valve II is provided at the bottom of the mineral powder metering bin.

[0011] Furthermore, one end of the mineral powder guide pipe extending out of the mineral powder metering bin is connected to a mineral powder sulfuric acid premixer; the mineral powder sulfuric acid premixer is a multi-stage injection mixing structure; the interior of the premixer is made of wear-resistant material; and a temperature control device is provided on the mineral powder sulfuric acid premixer.

[0012] Furthermore, the mineral powder sulfuric acid premixer is provided with a mixing chamber and an injection head; a premixing screw feeder is provided at the bottom of the premixer; a cooler is provided on one side of the premixing screw feeder; the premixing screw feeder includes a feeding bin and a feeding spiral auger; the feeding spiral auger is arranged in the feeding bin; a feed port is provided at the top of the feeding bin; the feed port and the injection head of the mineral powder sulfuric acid premixer are correspondingly connected; a discharge port is provided at the other end of the premixing screw feeder; and a reaction detection device is provided in the feeding bin.

[0013] Furthermore, the feeding spiral auger is connected to a driving device to drive its rotation; the spiral plate of the feeding spiral auger is of variable diameter type, and the pitch is large at one end close to the feeding port corresponding to the mineral powder sulfuric acid premixer and close to the feeding bin; the pitch of the spiral plates of the spiral auger gradually decreases along the direction from the feeding port to the discharge port, and the pitch between the previous adjacent spiral plates is set to L0; the pitch between the next adjacent spiral plates is set to L1; then L0-L1=Α, Α is a certain value.

[0014] Furthermore, the feeding bin of the premixed screw feeder is a double-layer structure; a water baffle is provided in the middle of the feeding bin; a plurality of water inlet holes with valves are provided on the water baffle; the bin body on the other side of the water baffle is a cooling bin; the cooling bin is filled with cooling water; a countercurrent auger is also provided in the cooling bin; the pitch value of the countercurrent auger is the same as the pitch value of the feeding spiral auger; the pitch rotation direction of the countercurrent auger is opposite to that of the feeding spiral auger; a temperature control device is provided in the cooling bin to regulate the water temperature; a controller II is also provided in the cooling bin; the controller II is electrically connected to the reaction detection device in the feeding bin and the valve on the water baffle.

[0015] Furthermore, the feeding bin of the premixing screw feeder is connected to the feeding pipe; the feeding pipe is connected to the acid hydrolysis reaction chamber; the feeding pipe is provided with a flow meter and a pressure sensor; a safety valve and an emergency shut-off system are provided at the entrance of the acid hydrolysis reaction chamber.

[0016] Furthermore, each device is provided with a fault self-diagnosis device.

[0017] It also includes a continuous acid hydrolysis method for titanium concentrate; the first step is: adding ore powder into a ore powder screening and processing bin; removing impurities from the ore powder in the ore powder screening and processing bin through a ore powder screening net and ore powder magnetic separation equipment; removing impurities and metal particles in the titanium ore powder; the screened titanium concentrate powder passes through a precision detection device; and after passing the detection, it enters a conveying device and is transported to a ore powder metering bin.

[0018] The second step: the weight sensor in the mineral powder metering bin detects the weight of the mineral concentrate; and the accuracy of the weight sensor is detected through the automatic calibration system; the target weight is set to β; the value of the target weight is stored in the data storage system; the weight sensor transmits the detected weight value to the data storage system; when the weight sensor detects that the weight of the titanium powder is 10 percent above or below β; an instruction is sent to the controller I through the data storage system to control the connecting valve I on the conveying system to stop the conveying device from feeding into the mineral powder metering bin.

[0019] The third step: setting the minimum weight detected by the weight sensor to β0; and transmitting and storing the data of β0 in the data storage system; when the weight sensor detects that the weight of the titanium powder is β0; sending instructions to the controller I through the data storage system to control the connecting valve II at the bottom of the mineral powder metering bin to allow the titanium concentrate powder to enter the mineral powder sulfuric acid premixer; and adding sulfuric acid with a concentration of 35%-40% into the mineral powder sulfuric acid premixer; premixing the sulfuric acid and the titanium concentrate powder in the mineral powder sulfuric acid premixer, and then injecting the mixed liquid into the premixing screw feeder through the injection head; feeding it to the discharge port of the feeding bin through the feeding spiral auger with variable diameter and pitch.

[0020] The fourth step: transport the cold water in the cooling bin to the opposite direction of the mineral powder sulfuric acid mixture in the feeding bin through a countercurrent auger, so that the flow direction of the cold water is opposite to the flow direction of the mineral powder sulfuric acid mixture to cool the feeding bin; control the temperature in the feeding bin at 34-36 degrees; detect the reaction degree of the titanium ore powder and sulfuric acid premix in the feeding bin through the sulfuric acid concentration detection device in the feeding bin; when the reaction degree is detected to be greater than a predetermined value; control the temperature control device through controller II to lower the cold water temperature in the cooling bin; and open the valve on the water barrier through controller II to input a certain amount of water into the feeding bin to reduce the concentration of sulfuric acid in the premixture.

[0021] The fifth step: after the premix is ​​fed, all valves on the baffle are opened through the controller II to send the countercurrent water flow into the feeding bin to clean the residue in the feeding bin.

[0022] Step 6: The premix in the feeding silo is fed into the acidolysis reaction silo for acidolysis reaction; the acidolysis reaction silo is filled with concentrated sulfuric acid with a concentration of more than 90%; and the temperature is controlled at a suitable reaction temperature for reaction; a safety valve and an emergency shut-off system are provided at the inlet of the acidolysis reactor to prevent abnormal pressure; the reaction of the reactor is quickly shut down in the event of abnormal pressure.

[0023] (3) Beneficial effects

[0024] The present invention accurately controls the amount of mineral powder entering the metering bin by providing a mineral powder metering bin and a weighing device and a control device in the metering bin; stops feeding when the amount is too much; and passes the mineral powder in the metering bin into a premixing device and sulfuric acid for premixing when the standard value is reached; and enters the premixing screw feeder by spraying for sufficient mixing; controls the temperature in the premixing screw feeder to 34-36 degrees by adding sulfuric acid of appropriate concentration and cooling water in the cooling bin during the premixing process, thereby preventing the reaction from occurring prematurely; monitors whether the reaction is proceeding through a reaction monitoring device, and adds water to reduce the sulfuric acid concentration and continue to control the temperature through the valve on the water barrier when the reaction is about to occur; dual action prevents reaction; and at the same time, washes with countercurrent water after feeding; this setting method fully premixes the titanium ore powder and sulfuric acid, advances the mixing time, avoids too long mixing time in the reactor, but at the same time does not react during premixing; avoids excessive heat in the reaction and substandard acid hydrolysis products. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attachment Figure 1 This is the flow chart of premixed acid hydrolysis for titanium ore powder processing.

[0026] Attachment Figure 2 This is a schematic diagram of the mineral powder metering bin.

[0027] Attachment Figure 3 Schematic diagram of the premixing screw feeder.

[0028] Attachment Figure 4 Schematic diagram of a double helix auger.

[0029] Attachment Figure 5 Schematic diagram of the reaction chamber.

[0030] 1- Mineral powder screening and processing chamber; 2- Mineral powder metering chamber; 3- Mineral powder sulfuric acid premixer; 4- Premixing screw feeder; 5- Feeding pipe; 6- Acid hydrolysis reaction chamber; 7- Conveying device; 8- Weight sensor; 9- Water baffle; 10- Feeding chamber; 11- Cooling chamber; 12- Injection head; 13- Feeding screw auger; 14- Countercurrent auger; 15- Mixing chamber; 16- Safety valve DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The application discloses a continuous acidolysis and acid premixing system for titanium concentrate, which comprises a mineral powder screening treatment bin 1, a conveying device 7, a mineral powder metering bin 2, a mineral powder sulfuric acid premixing device 3, a premixing screw feeder 4, a conveying pipe 5 and an acidolysis reaction bin 6; the mineral powder screening treatment bin is internally provided with a mineral powder screening net and a mineral powder magnetic separation device; the mineral powder screening net is arranged above the mineral powder magnetic separation device; the conveying device 7 is arranged between the mineral powder screening treatment bin 1 and the mineral powder metering bin 2 and connects the two bins; the conveying device 7 adopts a closed conveying system; the conveying device is provided with a communication valve I at both ends of the mineral powder screening treatment bin 1 and the mineral powder metering bin 2; the mineral powder metering bin 2 is internally provided with a weight sensor 8, an automatic calibration system, a controller I and a data storage system; the required amount of titanium concentrate powder in the mineral powder sulfuric acid premixing bin is input into the data storage system; one end of the conveying device 7 extending into the mineral powder metering bin is arranged above the weight sensor 8 and conveys the screened mineral powder to the weight sensor 8; the weight sensor 8 at the bottom of the mineral powder metering bin 2 is connected with the automatic calibration system; the weight sensor 8 is electrically connected with the controller; the controller I is connected with the data storage system; the bottom of the weight sensor is provided with a mineral powder guide pipe; the lower part of the mineral powder guide pipe penetrates through the mineral powder metering bin 2 and is provided with a communication valve II at the position of the bottom of the mineral powder metering bin 2; one end of the mineral powder guide pipe extending out of the mineral powder metering bin 2 is connected with the mineral powder sulfuric acid premixing device 3; the mineral powder sulfuric acid premixing device 3 is of a multi-stage jet mixing structure; the inside of the premixing device 3 is made of wear-resistant material; the mineral powder sulfuric acid premixing device 3 is provided with a temperature control device; the mineral powder sulfuric acid premixing device 3 is provided with a mixing cavity and a jet head 12; the bottom of the premixing device 3 is provided with the premixing screw feeder 4; one side of the premixing screw feeder 4 is provided with a cooler; the premixing screw feeder 4 comprises a feeding bin 10 and a feeding screw auger 13; the feeding screw auger 13 is arranged in the feeding bin 10; the top of the feeding bin 10 is provided with a feeding port; the feeding port is connected with the jet head 12 of the mineral powder sulfuric acid premixing device; the other end of the premixing screw feeder 4 is provided with a discharging port; the feeding bin is provided with a reaction detection device; the feeding screw auger 13 is connected with a driving device to drive the rotation of the feeding screw auger 13; the spiral plates of the feeding screw auger 13 are of a variable-diameter type; the pitch interval of the spiral plates of the feeding screw auger 13 gradually decreases from the feeding port to the discharging port; the pitch interval between the adjacent spiral plates is L0.The pitch between the next adjacent spiral plates is L1; then L0-L1=Α, Α is a certain value; the feeding bin 10 of the premixed screw feeder is a double-layer structure; a water baffle 9 is provided in the middle of the feeding bin 10; a plurality of water inlet holes with valves are provided on the water baffle 9; the bin body on the other side of the water baffle is a cooling bin 11; the cooling bin 11 is filled with cooling water; a countercurrent auger 14 is also provided in the cooling bin 11; the pitch value of the countercurrent auger 14 is the same as the pitch value of the feeding spiral auger; the pitch rotation direction of the countercurrent auger 14 is related to the feeding The auger 13 is opposite; a temperature control device is installed in the cooling chamber 11 to control the water temperature. A controller II is also installed in the cooling chamber 11. Controller II is electrically connected to the reaction detection device in the feed chamber and the valve on the baffle 9. The feed chamber 10 of the premixing screw feeder is connected to the feed pipe 5 below. The feed pipe 5 is connected to the acid hydrolysis reaction chamber 6. A flow meter and a pressure sensor are installed on the feed pipe 5. A safety valve 16 and an emergency shut-off system are installed at the entrance of the acid hydrolysis reaction chamber 6. All devices are equipped with fault self-diagnosis devices.

Claims

1. A continuous acid hydrolysis and acid premixing system for titanium concentrate; comprising a slag screening and processing chamber, a conveying device, a slag metering chamber, a slag sulfuric acid premixer, a premixing screw feeder, a feeding pipe, and an acid hydrolysis reaction chamber; a slag screening net and a slag magnetic separation device are provided in the slag screening and processing chamber; the slag screening net is provided above the slag magnetic separation device; the conveying device is provided in the slag screening and processing chamber and the slag metering chamber and connects the two chambers; the conveying device adopts a closed conveying system; the conveying system is provided with a connecting valve I at both ends connecting the slag screening and processing chamber and the slag metering chamber; a weight is provided in the slag metering chamber The ore powder sulfuric acid premixer is provided with a mixing chamber and a spray head; a premixing screw feeder is provided at the bottom of the premixer; a cooler is provided on one side of the premixing screw feeder; the premixing screw feeder includes a feeding bin and a feeding screw auger; the feeding screw auger is provided in the feeding bin; the feeding bin is provided with an inlet. The feed port is connected to the injection head of the slag sulfuric acid premixer; the other end of the premixing screw feeder is provided with a discharge port; a reaction detection device is provided in the feeding bin; the feeding spiral auger is connected to the driving device to drive it to rotate; the spiral plate of the feeding spiral auger is of variable diameter type, and the pitch is large at the end close to the feed port corresponding to the slag sulfuric acid premixer close to the feeding bin; the pitch of the spiral plates of the spiral auger gradually decreases along the direction from the feed port to the discharge port, and the pitch between the previous adjacent spiral plates is set to L0; the pitch between the next adjacent spiral plates is set to L1; then L0-L1=Α, Α is a certain value; the feeding bin of the premixed screw feeder is a double-layer structure; a water baffle is provided in the middle of the feeding bin; a plurality of water inlet holes with valves are provided on the water baffle; the bin body on the other side of the water baffle is a cooling bin; the cooling bin is filled with cooling water; a countercurrent auger is also provided in the cooling bin; the pitch value of the countercurrent auger is the same as the pitch value of the feeding spiral auger; the pitch rotation direction of the countercurrent auger is opposite to that of the feeding spiral auger; a temperature control device is provided in the cooling bin to regulate the water temperature; a controller II is also provided in the cooling bin; the controller II is electrically connected to the reaction detection device in the feeding bin and the valve on the water baffle.

2. The titanium concentrate continuous acid decomposition and premixing system according to claim 1, characterized in that: The bottom weight sensor of the mineral powder metering bin is connected to the automatic calibration system; the weight sensor is electrically connected to the controller; the controller I is connected to the data storage system; a mineral powder guide pipe is provided at the bottom of the weight sensor; the lower part of the mineral powder guide pipe passes through the mineral powder metering bin and a connecting valve II is provided at the bottom of the mineral powder metering bin.

3. The titanium concentrate continuous acid decomposition and premixing system according to claim 2, characterized in that: One end of the ore powder guide pipe extending out of the ore powder metering bin is connected to a ore powder sulfuric acid premixer; the ore powder sulfuric acid premixer is a multi-stage injection mixing structure; the interior of the premixer is made of wear-resistant material; and a temperature control device is provided on the ore powder sulfuric acid premixer.

4. The titanium concentrate continuous acid decomposition and premixing system according to claim 3, characterized in that: The feeding bin of the premixing screw feeder is connected to the feeding pipe below; the feeding pipe is connected to the acidolysis reaction bin; a flow meter and a pressure sensor are provided on the feeding pipe; a safety valve and an emergency shut-off system are provided at the entrance of the acidolysis reaction bin; each device is provided with a fault self-diagnosis device.

5. A continuous acid hydrolysis method using the acid premixing system for continuous acid hydrolysis of titanium concentrate according to any one of claims 1 to 4, comprising the following steps: Step 1: Add the mineral powder to the mineral powder screening and processing chamber; in the mineral powder screening and processing chamber, remove impurities and metal particles from the titanium ore powder through the mineral powder screening net and mineral powder magnetic separation equipment; The titanium concentrate powder after screening passes the precision detection device; after passing the detection, it enters the conveying device and is transported to the mineral powder metering bin; The second step: The weight sensor in the mineral powder metering bin detects the weight of the mineral concentrate; and the accuracy of the weight sensor is tested through the automatic calibration system; The target weight is set to β; the target weight value is stored in the data storage system; the weight sensor transmits the detected weight value to the data storage system; when the weight sensor detects that the titanium powder weight is within 10 percent of β, the data storage system sends a command to the controller I to control the connecting valve I on the conveying system to stop the conveying device from feeding the mineral powder metering bin; The third step: setting the minimum weight detected by the weight sensor to β0; and transmitting and storing the data of β0 in the data storage system; when the weight sensor detects that the weight of the titanium powder is β0; sending an instruction to the controller I through the data storage system to control the connecting valve II at the bottom of the mineral powder metering bin to allow the titanium concentrate powder to enter the mineral powder sulfuric acid premixer; and adding sulfuric acid with a concentration of 35%-40% into the mineral powder sulfuric acid premixer; premixing the sulfuric acid and the titanium concentrate powder in the mineral powder sulfuric acid premixer, and then injecting the mixed liquid into the premixing screw feeder through the injection head; and feeding the mixed liquid to the discharge port of the feeding bin through the feeding screw auger with a variable diameter pitch; The fourth step is to transport the cold water in the cooling bin in the opposite direction of the mineral powder sulfuric acid mixture in the feeding bin through a countercurrent auger, so that the flow direction of the cold water is opposite to the flow direction of the mineral powder sulfuric acid mixture to cool the feeding bin; the temperature in the feeding bin is controlled at 34-36 degrees; the reaction degree of the titanium ore powder and sulfuric acid premix in the feeding bin is detected by a sulfuric acid concentration detection device in the feeding bin; when the reaction degree is detected to be greater than a predetermined value, the temperature of the cold water in the cooling bin is lowered by the temperature control device through the controller II; and the valve on the water barrier is opened by the controller II to input a certain amount of water into the feeding bin to reduce the concentration of sulfuric acid in the premixture; The fifth step: after the premix is ​​fed, all valves on the baffle are opened by the controller II to send the countercurrent water flow into the feeding bin to clean the residue in the feeding bin; Step 6: The premix in the feeding silo is fed into the acidolysis reaction silo for acidolysis reaction; the acidolysis reaction silo is filled with concentrated sulfuric acid with a concentration of more than 90%; and the temperature is controlled at a suitable reaction temperature for reaction; a safety valve and an emergency shut-off system are provided at the inlet of the acidolysis reactor to prevent abnormal pressure; the reaction of the reactor is quickly shut down in the event of abnormal pressure.

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