Catalyst-doped magnesium-making raw material grinding and ball pressing system and catalyst-doped magnesium-making raw material grinding and ball pressing method

Abstract

The invention belongs to the technical field of non-ferrous metal metallurgy, and discloses a catalyst-doped magnesium preparation raw material grinding and ball pressing system and method, and the system comprises a grinding mechanism, a ball pressing mechanism and a dry gas protection mechanism; a first pressure sensor and a humidity sensor are mounted in the sealed grinding chamber and the grinding bin; a first electromagnetic valve and a first gas flow meter are mounted on each of the three first branch breather pipes; according to monitoring data of a first pressure sensor, the amount and the flow speed of dry gas entering the sealed grinding chamber, the powder grinding bin and the powder grinding buffer chamber are controlled in real time through a first electromagnetic valve and a first gas flow meter; different premixing treatment of the calcium carbide catalyst, the magnesium smelting raw material and the carbon reducing agent in the grinding link is achieved, the problems that after the raw materials absorb moisture in the grinding and mixing process, the catalyst is consumed, the quality of the magnesium raw material is reduced, and the explosion danger is increased are solved, the safety of the magnesium smelting process is improved, and the production cost is reduced. And the application of the magnesium smelting process is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal smelting, and particularly relates to a catalyst-doped magnesium raw material grinding and pelletizing system and method. Background Art

[0002] The carbothermal reduction magnesium refining (VCTRM) process has the advantages of low cost, low energy consumption, low resource consumption, and environmental protection. It is considered to be an ideal clean production process for magnesium. Compared with the Pidgeon process and the electrolytic process, the vacuum carbothermal reduction method reduces energy consumption by 42.9% and 27.5%, respectively. And compared with the Pidgeon process, the carbothermal method can produce a wider range of raw materials. Both magnesite and magnesia nickel ore can be used as raw materials for extracting metallic magnesium.

[0003] Before adding magnesium smelting raw materials such as magnesite and magnesia nickel ore to the reaction device, they need to be ground and pressed into balls. At present, after the magnesium smelting raw materials are ground, the hygroscopicity of the magnesium smelting raw materials increases due to the increase in the specific surface area of ​​the particles. As the specific surface area increases, the surface area of ​​the ground powder increases, thereby increasing its surface area exposed to the air, making it easier to absorb moisture in the air, increasing hygroscopicity and reducing the utilization rate of the raw materials. It will also cause oxidation problems. The increased specific surface area will also increase the contact area between oxygen and the ground powder, increasing the possibility of oxidation. The ground powder is prone to oxidation reaction when it comes into contact with oxygen in the air, causing product deterioration and reducing its use value. In addition, there will be problems of difficulty in storage and subsequent ball pressing, and the storage cost is high.

[0004] Catalytic carbon reduction magnesium refining is to pre-mix and add calcium carbide catalyst in the grinding stage, then make powder and press into balls. Under the action of catalyst, it can not only improve the efficiency of magnesium production in the reaction magnesium production stage, but also make the reduction slag more widely used. However, since calcium carbide catalyst can easily react with water to produce acetylene, the humidity environment requirements of the grinding system and method are very strict.

[0005] Even though powdered carbon reducing agents are relatively easy to obtain from manufacturers, they also have the problem of being easy to absorb moisture due to their large specific surface area. Therefore, it is more effective to mix blocky carbon particles with magnesium smelting raw materials and calcium carbide catalysts, grind them into powder, and press them into balls. Summary of the invention

[0006] The purpose of the present invention is to provide a magnesium raw material grinding and pelletizing system and method doped with a catalyst, so as to prevent the raw material from absorbing moisture during the grinding and mixing process, thereby consuming the catalyst itself, reducing the quality of the magnesium raw material, and increasing the risk of explosion, thereby improving the safety of the magnesium smelting process. Through the implementation of the present invention, the application of the magnesium smelting process is promoted.

[0007] To achieve the above purpose, the technical solution of the present invention is: A catalyst-doped magnesium raw material grinding and ball pressing system, comprising a grinding mechanism, a ball pressing mechanism and a dry gas protection mechanism; The grinding mechanism comprises a grinding mill body, a cyclone separator, a blower, and a grinding mill bin. A first sealed screw conveyor is provided at a feed inlet on one side of the grinding mill body, one to three feed hoppers are provided at the feed end of the first sealed screw conveyor, and a sealed discharger is provided at the discharge end of each feed hopper; The inside of the mill body is a sealed grinding chamber, the top of the sealed grinding chamber is connected to the inlet end of the cyclone separator through a first pipe, the top air outlet of the cyclone separator is connected to the blower through a second pipe, and the air outlet of the blower is connected to the bottom of the sealed grinding chamber through a third pipe, so that internal circulating wind is formed between the sealed grinding chamber, the cyclone separator and the blower, the discharge end of the cyclone separator is connected to the grinding bin through a fourth pipe, and a closed discharger is provided at the discharge end of the cyclone separator; The ball pressing mechanism comprises a ball pressing machine body, a second sealed screw conveyor is arranged on the ball pressing machine body, a grinding buffer chamber is arranged in the ball pressing machine body, a gas overflow port is arranged on the grinding buffer chamber, a ball pressing roller pair is arranged below the grinding buffer chamber, a ball pressing finished product outlet is arranged below the ball pressing roller pair, and a grinding bin is connected to the second sealed screw conveyor through a sealed lifting pipeline; The dry gas protection mechanism comprises a dry gas source, a gas outlet of the dry gas source is connected to a first main ventilation pipe, three first branch ventilation pipes are arranged on the first main ventilation pipe, one of the first branch ventilation pipes is connected to a first sealed screw conveyor, another first branch ventilation pipe is connected to a powder grinding bin, and the third first branch ventilation pipe is connected to a second sealed screw conveyor; A first pressure sensor and a humidity sensor are installed in the sealed grinding chamber and the grinding bin, and a first electromagnetic valve and a first gas flow meter are installed on the three first branch ventilation pipes; according to the monitoring data of the first pressure sensor, the amount and flow rate of the dry gas entering the sealed grinding chamber, the grinding bin and the grinding buffer chamber are controlled in real time through the first electromagnetic valve and the first gas flow meter to ensure that the sealed grinding chamber, the grinding bin and the grinding buffer chamber have a dry gas environment that meets the requirements.

[0008] Furthermore, a bag dust collector is provided, a fourth pipe is connected between the air inlet end of the bag dust collector and the third pipe, a second electromagnetic valve is installed on the fourth pipe, the discharge end of the bag dust collector is connected to the grinding bin through a fifth pipe, a closed discharger is provided at the discharge end of the bag dust collector, and the air outlet end of the bag dust collector is discharged to the outside after treatment; A second pressure sensor is installed on the fourth pipeline, and a second gas flow meter is installed on the second pipeline. The air volume and internal pressure of the internal circulation air are controlled in real time according to the detection data of the second pressure sensor and the second gas flow meter.

[0009] Furthermore, it also includes an inert gas storage tank, the gas outlet end of the inert gas storage tank is connected to a second main ventilation pipe, and three second branch ventilation pipes are arranged on the second main ventilation pipe, one of the second branch ventilation pipes is connected to the sealed grinding chamber, another second branch ventilation pipe is connected to the grinding bin, and the third second branch ventilation pipe is connected to the grinding buffer chamber, and a third electromagnetic valve and a third gas flow meter are installed on the three second branch ventilation pipes; the third electromagnetic valve and the third gas flow meter are used to control the amount and flow rate of dry gas entering the sealed grinding chamber, the grinding bin and the grinding buffer chamber in real time to ensure that the sealed grinding chamber, the grinding bin and the grinding buffer chamber achieve a dry, low-oxygen gas environment that meets the requirements.

[0010] Furthermore, a hot air furnace is provided, and a hot air duct is connected between the hot air furnace and the sealed grinding chamber and the grinding buffer chamber. A fourth electromagnetic valve and a fourth gas flow meter are provided on the hot air duct. According to the monitoring data of the humidity sensors in the sealed grinding chamber and the grinding buffer chamber, the amount and flow rate of hot air entering the sealed grinding chamber and the grinding buffer chamber are controlled in real time through the fourth electromagnetic valve and the fourth gas flow meter to ensure that the sealed grinding chamber and the grinding buffer chamber reach the required dryness and temperature environment.

[0011] The present invention also provides a method for grinding and pelletizing a catalyst and a magnesium raw material premix, wherein the grinding and pelletizing methods include three forms: The first method is to grind the calcium carbide catalyst and magnesium smelting raw materials separately, pre-mix them and then press them into balls: Adding calcium carbide catalyst and magnesium smelting raw material into two feed hoppers respectively, grinding the calcium carbide catalyst and magnesium smelting raw material respectively, the particle size of calcium carbide catalyst after grinding is ≥100 mesh, and the particle size of magnesium smelting raw material is ≥120 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, grinding bin and grinding buffer chamber reach the required dry gas environment, the humidity is less than 20%, and the dry gas pressure is 0.05~0.15Mpa; the wind speed of the internal circulation air formed between the sealed grinding chamber, cyclone separator and blower is controlled at 3~25m / s; After the grinding is completed, the powder is pre-mixed in the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

[0012] Preferably, the calcium carbide catalyst and the magnesium smelting raw material are ground and mixed in a mass ratio of 35%±5%:35%±5%; during the grinding and ball pressing process, or by opening the inert gas storage tank at the same time, the sealed grinding chamber, grinding bin, and grinding buffer chamber are allowed to achieve an anti-oxidation environment that meets the requirements.

[0013] The second method is to pre-mix the calcium carbide catalyst and magnesium smelting raw materials, then grind them into powder and finally press them into balls: Add the calcium carbide catalyst and the magnesium smelting raw material into the feed hopper, and enter the sealed grinding chamber through the first sealed screw conveyor for premixing, and then grind the mixture of the two, and the particle size of the mixture after grinding is ≥80 mesh, preferably ≥100 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, the grinding bin, and the grinding buffer chamber reach a dry gas environment that meets the requirements, with a humidity of less than 20%, a dry gas pressure of 0.05-0.15 MPa, and the wind speed of the internal circulation wind formed between the sealed grinding chamber, the cyclone separator, and the blower is controlled at 3-25 m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

[0014] Preferably, the calcium carbide catalyst and the magnesium smelting raw material are ground and mixed in a mass ratio of 35%±5%:35%±5%; during the grinding process, or at the same time, the inert gas storage tank is opened to allow the sealed grinding chamber, grinding bin, and grinding buffer chamber to achieve an anti-oxidation environment that meets the requirements.

[0015] The third method is to pre-mix the calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent at the same time, then grind them into powder and finally press them into balls: Adding calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent into the feed hopper, all three enter the sealed grinding chamber through the first sealed screw conveyor for premixing, and then grind the mixture of the three, and the particle size of the mixture after grinding is ≥80 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, the grinding bin and the grinding buffer chamber reach the required dry gas environment, the humidity is less than 20%, the dry gas pressure is 0.05~0.15MPa, and the wind speed of the internal circulation air formed between the sealed grinding chamber, the cyclone separator and the blower is controlled at 3~25m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

[0016] Preferably, the calcium carbide catalyst, magnesium smelting raw material, and carbon reducing agent are mixed in a mass ratio of 35%±4%: 35%±4%: 30%±2%; during the grinding process, or at the same time, the inert gas storage tank is opened to allow the sealed grinding chamber, the grinding bin, and the grinding buffer chamber to achieve an anti-oxidation environment that meets the requirements. The present invention is based on a new catalytic carbothermal magnesium smelting method, using calcined dolomite (CaMgO2) as raw material, coke (C) as reducing agent, calcium carbide (CaC2) as catalyst, in an electrically heated vacuum reduction reactor, the following reduction reaction occurs:

[0017] Among them, the following reactions occur after the calcium carbide (CaC2) catalyst absorbs moisture:

[0018] During the reaction, acetylene is generated, which not only consumes the calcium carbide (CaC2) catalyst itself, thereby reducing the quality of the magnesium raw material, but also increases the risk of explosion, and places extremely high demands on the reaction environment. Therefore, it can be pretreated in the grinding stage and then reduced to produce magnesium, which will be a new magnesium production process, and this is also the purpose of this application.

[0019] Through the design of the grinding system, the present invention can prevent the raw materials from absorbing moisture during the grinding and mixing process, which not only consumes the catalyst itself, reduces the quality of the magnesium raw materials, but also increases the risk of explosion, thereby improving the safety of the magnesium smelting process.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1) The grinding system of the present invention is designed with dry gas protection, which provides a dry gas environment for the sealed grinding chamber, grinding bin and grinding buffer chamber at the same time, thereby avoiding the problem of the grinding powder coming into contact with moisture in the air and absorbing moisture to cause a reaction, and also preventing the raw materials from absorbing moisture during the grinding and mixing process, which not only consumes the catalyst itself, reduces the quality of the magnesium raw materials, but also increases the risk of explosion, thereby improving the safety of the magnesium smelting process.

[0021] 2) The present invention realizes the integration of the two processes of grinding and pelletizing of magnesium ore. After grinding, the ore directly enters the pelletizing process. The whole system is in a sealed state, with a compact overall structure, low cost and high production efficiency.

[0022] 3) The grinding system of the present invention is designed to use inert gas to provide an inert gas environment for the sealed grinding chamber, grinding bin, and grinding buffer chamber, thereby avoiding oxidation caused by contact between the grinding powder and oxygen in the air and improving its use value.

[0023] 4) The grinding system of the present invention has a closed design for each link such as feeding and conveying, so that the entire process of grinding and storage is carried out in a closed environment, preventing dust from overflowing and scattering, and greatly improving the working environment of the workshop.

[0024] 5) The grinding system of the present invention further ensures the dryness of the sealed grinding room environment by setting up a hot air furnace, and further solves the problem of moisture deterioration.

[0025] 6) During the grinding process, the grinding system of the present invention uses a bag filter to separate the magnesium ore powder and directly stores it in the grinding bin for standby use. The separated dry gas can still be returned for recycling, thereby greatly saving costs and improving the utilization rate of dry gas.

[0026] 7) The grinding method of the present invention has three grinding modes, which realize different pre-mixing treatments of the calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent in the grinding process, and prevent the raw material from absorbing moisture during the grinding and mixing process, which not only consumes the catalyst itself, reduces the quality of the magnesium raw material, but also increases the risk of explosion. The safety of the magnesium smelting process is improved, and the application of the magnesium smelting process is promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention in specific embodiment 1; Figure 2 It is a structural schematic diagram of the present invention in specific embodiment 2; Figure 3 It is a structural schematic diagram of the present invention in specific embodiment 3. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings. Specific embodiments

[0029] like Figure 1 As shown, the catalyst-doped magnesium raw material grinding and pelletizing system of the present invention comprises a grinding mechanism, a pelletizing mechanism and a dry gas protection mechanism; The grinding mechanism includes a grinding mill body B3, a cyclone separator B5, a blower B7, and a grinding mill bin C2. A first sealed screw conveyor B2 is provided at the feed port on one side of the grinding mill body B3. One to three feed hoppers B1 are provided at the feed end of the first sealed screw conveyor B2. A sealed discharger is provided at the discharge end of each feed hopper B1. The mill body B3 can be a Raymond mill, and the interior of the mill body B3 is a sealed grinding chamber B9, the top of the sealed grinding chamber B9 is connected to the inlet end of the cyclone separator B5 through a first pipe B4, the top air outlet of the cyclone separator B5 is connected to the blower B7 through a second pipe B6, and the air outlet of the blower B7 is connected to the bottom of the sealed grinding chamber B9 through a third pipe B8, so that internal circulation wind is formed between the sealed grinding chamber B9, the cyclone separator B5, and the blower B7, the discharge end of the cyclone separator B5 is connected to the grinding bin C2 through a fourth pipe C1, and a closed discharger is provided at the discharge end of the cyclone separator B5; The ball pressing mechanism comprises a ball press machine body D4, on which a second sealed screw conveyor D3 is arranged, a grinding buffer chamber D10 is arranged inside the ball press machine body D4, a gas overflow port D5 is arranged on the grinding buffer chamber D10, and the gas is discharged to the outside by a fan D8 after being processed at the air outlet end of the gas overflow port D5, or collected and re-entered into the second sealed screw conveyor D3 for use; a ball pressing roller pair D6 is arranged below the grinding buffer chamber D10, and a ball pressing finished product outlet is arranged below the ball pressing roller pair D6, and a material receiving box D7 is arranged below the ball pressing finished product outlet, and the material receiving box D7 is connected to the finished product storage tank body D9; the grinding bin C2 is connected to the feed hopper D2 through the pipeline C3 and the sealed lifting pipeline D1, and the feed hopper D2 is connected to the feeding end of the second sealed screw conveyor D3; The dry gas protection mechanism includes a dry gas source A1, the gas outlet end of the dry gas source A1 is connected to a first main ventilation pipe A2, and three first branch ventilation pipes A4, A5, and A11 are arranged on the first main ventilation pipe A2, wherein one first branch ventilation pipe A4 is connected to a first sealed screw conveyor B2, another first branch ventilation pipe A5 is connected to a grinding bin C2, and the third first branch ventilation pipe A11 is connected to a second sealed screw conveyor D3, and another branch ventilation pipe A8 connected to a lifting pipe D1 can be arranged, and a first electromagnetic valve A10 and a first gas flow meter A9 are arranged on the branch ventilation pipe A8; A first pressure sensor and a humidity sensor are installed in the sealed grinding chamber B9, the grinding bin C2 and the grinding buffer chamber D10, and first electromagnetic valves A2, A7, A13 and first gas flow meters A3, A6, A12 are installed on the three first branch ventilation pipes A14, A5 and A11; according to the monitoring data of the first pressure sensor, the amount and flow rate of the dry gas entering the sealed grinding chamber B9, the grinding bin C2 and the grinding buffer chamber D10 are controlled in real time through the first electromagnetic valves A2, A7, A13 and the first gas flow meters A3, A6, A12 to ensure that the sealed grinding chamber B9, the grinding bin C2 and the grinding buffer chamber D10 reach a dry gas environment that meets the requirements. Among them, the grinding and ball pressing system is also provided with a controller, and the mill body B3, sealed screw conveyor B2, closed discharger, cyclone separator B3, discharge valve, blower B7, first electromagnetic valve A2, A7, A13 and first gas flow meter A3, A6, A12 are all electrically connected to the controller to realize the control of the working status of each part and sensor.

[0030] During operation, the crushed magnesium ore is put into the feed hopper B1, and is transported to the sealed grinding chamber B9 of the mill body B3 by the action of the first closed screw conveyor B2. After being ground in the sealed grinding chamber B9, the fine powder that meets the requirements is transported into the cyclone separator B5 through the first pipeline B4 under the action of the internal blowing air flow of the blower B7. The magnesium ore powder separated by the cyclone separator B5 enters the grinding bin C2 through the bottom outlet and the fourth pipeline C1 for storage and standby. Relatively clean wind with a small amount of magnesium ore powder passes through the top outlet of the cyclone separator B5 and the second pipeline B6 and is pumped into the sealed grinding chamber B9 of the mill body B3 through the blower B7, thereby forming a sealed internal circulation airflow between the sealed grinding chamber B9, the cyclone separator B5 and the blower B7. In this process, the amount of dry gas entering the sealed grinding chamber B9 and the grinding buffer chamber D10 is controlled in real time through the monitoring data of the pressure sensors in the sealed grinding chamber B9, the grinding bin C2 and the grinding buffer chamber D10 and the first solenoid valves A2, A7, A13 and the first gas flow meters A3, A6 connected to the three first branch ventilation pipes A14, A5, A11, so as to ensure that the sealed grinding chamber B9 and the grinding buffer chamber D10 reach the required dry gas environment.

[0031] After the grinding is completed, the powder enters the grinding bin C2, and then is lifted to the second sealed screw conveyor D3 through the lifting pipe D10, and enters the grinding buffer chamber D10, and is pressed into balls under the action of two ball pressing rollers D6.

[0032] In summary, the entire process of grinding is always in a closed state, and a dry gas environment is provided to the sealed grinding chamber B3, grinding bin C2, and grinding buffer chamber D10 at the same time, avoiding the problem of reaction caused by moisture absorption due to contact between the grinding powder and the moisture in the air, and preventing the raw materials from absorbing moisture during the grinding, mixing and ball pressing processes, which not only consumes the catalyst itself, reduces the quality of the magnesium raw materials, but also increases the risk of explosion, thereby improving the safety of the magnesium smelting process.

[0033] like Figure 2 As shown, a bag dust collector E4 is additionally provided on the basis of Example 1, a fourth pipe E2 is connected between the air inlet end of the bag dust collector E4 and the third pipe B8, a second electromagnetic valve E1 is installed on the fourth pipe E2, a discharge end of the bag dust collector E4 is connected to the grinding bin C2 through a fifth pipe E3, a closed discharger is provided at the discharge end of the bag dust collector E4, and the air outlet end of the bag dust collector E4 is discharged to the outside or collected for standby use by a fan E5 after being processed.

[0034] Through the above-mentioned arrangement, the excess circulating air in the mill body B3 is processed, which has a direct effect on the flow rate and pressure of the circulating air in the mill body B3. Since the magnesium ore powder content in the airflow in the third pipeline B8 is relatively small, the magnesium ore powder and the dry gas can be better separated after being processed by the bag dust collector E4. Therefore, the magnesium ore powder separated by the bag dust collector E4 can be directly stored in the grinding bin C2 for standby use, and the separated dry gas can still be returned to the first sealed screw conveyor B2 for recycling, thereby greatly saving costs and improving the utilization rate of dry gas.

[0035] A second pressure sensor E6 is installed on the fourth pipeline E2, and a second gas flow meter E7 is installed on the second pipeline B6. The air volume and internal pressure of the internal circulation air are controlled in real time according to the detection data of the second pressure sensor E6 and the second gas flow meter E7.

[0036] Through the above-mentioned arrangement, the excess circulating air in the mill body B3 is processed, and the flow rate (3-15m / s) and pressure (300-1000Pa) of the circulating air in the mill body B3 are also regulated. Since the content of magnesium ore powder in the pipeline airflow at the top outlet of the cyclone separator B5 is relatively small, the magnesium ore powder and the dry gas can be better separated after this part of the airflow is processed by the bag dust collector E48. Therefore, the magnesium ore powder separated by the bag dust collector E4 can be directly stored in the grinding bin C2 for standby use, and the separated dry gas can still be returned to the closed screw conveyor B2 for recycling, thereby greatly saving costs and improving the utilization rate of dry gas.

[0037] like Figure 3As shown, on the basis of specific embodiment 2, it also includes an inert gas storage tank F1, the outlet end of the inert gas storage tank F1 is connected to a second main ventilation pipe F2, and three second branch ventilation pipes F3, F6, and F12 are arranged on the second main ventilation pipe F2, wherein one second branch ventilation pipe F3 is connected to the sealed grinding chamber B9, another second branch ventilation pipe F6 is connected to the grinding bin C2, and the third second branch ventilation pipe F12 is connected to the grinding buffer chamber D10, and the three second branch ventilation pipes F3, F6, and F12 are connected to the grinding buffer chamber D10. The third electromagnetic valves F5, F8, F14 and the third gas flowmeters F4, F7, F13 are installed on the pipes F3, F6, and F12; the amount and flow rate of the dry gas entering the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 are controlled in real time by the third electromagnetic valves F5, F8, F14 and the third gas flowmeters F4, F7, and F13 to ensure that the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 reach the required dry and low oxygen gas environment. At the same time, another second branch ventilation pipe F9 can also be set, and the third electromagnetic valve F11 and the third gas flowmeter F10 are installed on the second branch ventilation pipe F9.

[0038] In addition, as needed, a hot air furnace G1 can be set up, and hot air ducts G2 and G7 are connected between the hot air furnace G1 and the sealed grinding chamber B9 and the grinding buffer chamber D10. Fourth electromagnetic valves G4 and G5 and fourth gas flow meters G3 and G6 are respectively provided on the hot air ducts GG2 and G7. According to the monitoring data of the humidity sensors in the sealed grinding chamber B9 and the grinding buffer chamber D10, the amount and flow rate of hot air entering the sealed grinding chamber B9 and the grinding buffer chamber D10 are controlled in real time through the fourth electromagnetic valves G4 and G5 and the fourth gas flow meters G3 and G6 to ensure that the sealed grinding chamber and the grinding buffer chamber D10 reach the required dryness and temperature environment.

[0039] The present invention also provides a method for grinding a premixed catalyst and a magnesium raw material, wherein the grinding method has three forms: The first method is to grind the calcium carbide catalyst and magnesium smelting raw materials separately, pre-mix them and then press them into balls: Add the calcium carbide catalyst and magnesium smelting raw material into two feed hoppers B1 respectively, grind the calcium carbide catalyst and magnesium smelting raw material successively, the particle size of the calcium carbide catalyst after grinding is ≥100 mesh, and the particle size of the magnesium smelting raw material is ≥120 mesh; during the grinding process, always open the dry gas source A1, let the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 reach the required dry gas environment, the humidity is less than 20%, and the dry gas pressure is 0.05~0.15Mpa; the wind speed of the internal circulation air formed between the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 is controlled at 3~25m / s; After the grinding is completed, the powder is pre-mixed in the grinding bin C2 and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas overflow port D5 controls the gas outlet pressure through the gas solenoid valve D11: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing roller D6 is controlled by adjusting the rotation speed of the second sealed screw conveyor D3 and the oil pump pressure between the two ball pressing rollers D6. Among them, the rotation speed of the second sealed screw conveyor D3 is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers D6 is: 10~30MPa, and the linear pressure between the two ball pressing rollers D6 is: 5t / cm~20t / cm.

[0040] Furthermore, the mixing ratio of the calcium carbide catalyst and the magnesium refining raw material after grinding is 35%±5%:35%±5% by mass; during the grinding process, or at the same time, the inert gas storage tank F1 is opened to allow the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 to reach an anti-oxidation environment that meets the requirements.

[0041] In this embodiment, specifically, first open the dry gas source A1, and introduce dry gas with a humidity of 15%-20% into the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10. The dry gas pressure is 0.15Mpa, and the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 are turned on to form an internal circulation wind. The wind speed of the internal circulation wind is controlled at 18m / s, and then the calcium carbide catalyst with a particle size of about 20mm in the silo is added to the feed hopper B1 for grinding, and the powder is ground to about 110 mesh; the calcined white with a particle size of about 30mm in the silo is added to the feed hopper B1 for grinding, and the powder is ground to about 130 mesh; then the calcium carbide catalyst and the calcined white are pre-mixed in the grinding bin C2 and then enter the ball pressing mechanism for ball pressing.

[0042] During the ball pressing process, the gas outlet pressure of the gas overflow port D5 is: 0.15MPa, the speed of the second sealed screw conveyor D3 is: 1000r / min, the oil pump pressure between the two ball pressing rollers D6 is: 20MPa, and the line pressure between the two ball pressing rollers D6 is: 15t / cm.

[0043] The second method is to pre-mix the calcium carbide catalyst and magnesium smelting raw materials, then grind them into powder and finally press them into balls: Calcium carbide catalyst and magnesium smelting raw material are added into the feed hopper B1, and they are both introduced into the sealed grinding chamber B9 through the first sealed screw conveyor B2 for premixing, and then the mixture is ground, and the particle size of the mixture after grinding is ≥80 mesh, preferably ≥100 mesh; during the grinding process, the dry gas source A1 is always opened to allow the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 to reach the required dry gas environment, with a humidity of less than 20%, and a dry gas pressure of 0.05-0.15 MPa, and the wind speed of the internal circulation wind formed between the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 is controlled at 3-25 m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the overflow port D5 controls the gas outlet pressure through the gas solenoid valve D11: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

[0044] Furthermore, the mixing ratio of the calcium carbide catalyst and the magnesium refining raw material after grinding is 35%±5%:35%±5% by mass; during the grinding process, or at the same time, the inert gas storage tank F1 is opened to allow the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 to reach an anti-oxidation environment that meets the requirements.

[0045] In this embodiment, specifically, first open the dry gas source and the inert gas storage tank F1, introduce inert gas (argon) and dry gas with a humidity of 15%-20% into the sealed grinding chamber B9 and the grinding buffer chamber D10, the dry gas pressure is 0.10Mpa, open the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 to form an internal circulation wind, and the wind speed of the internal circulation wind is controlled at 10m / s. Open the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 to form an internal circulation wind, and then add the calcium carbide catalyst with a particle size of about 15mm in the silo and the calcined white with a particle size of about 25mm in the silo to the feed hopper B1 at the same time for grinding, and grind to about 110 mesh; the grinding process also plays a role of pre-mixing, which can reduce the moisture absorption of the subsequent formal mixing process, and at the same time open the bag dust collector E4 for dust collection.

[0046] During the ball pressing process, the gas outlet pressure of the gas overflow port D5 is: 0.1MPa, the speed of the second sealed screw conveyor D3 is: 800r / min, the oil pump pressure between the two ball pressing rollers D6 is: 12MPa, and the line pressure between the two ball pressing rollers D6 is: 18t / cm.

[0047] The third method is to pre-mix the calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent at the same time, then grind them into powder and finally press them into balls: Calcium carbide catalyst, magnesium refining raw material and carbon reducing agent are added into the feed hopper, and all three enter the sealed grinding chamber B9 through the first sealed screw conveyor B2 for premixing, and then the mixture of the three is ground, and the particle size of the mixture after grinding is ≥80 mesh; during the grinding process, the dry gas source A1 is always opened to allow the sealed grinding chamber B9, the grinding bin C2, and the grinding buffer chamber D10 to reach a dry gas environment that meets the requirements, with a humidity of less than 20% and a dry gas pressure of 0.05-0.15 MPa, and the wind speed of the internal circulation air formed between the sealed grinding chamber B9, the cyclone separator B5, and the blower B7 is controlled at 3-25 m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas overflow port D5 controls the gas outlet pressure through the gas solenoid valve D11: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing roller D6 is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers D6. Among them, the speed of the second sealed screw conveyor D3 is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers D6 is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

[0048] Furthermore, the mixing ratio of the calcium carbide catalyst, magnesium refining raw material and carbon reducing agent is 35%±5%:35%±5%:30%±3% by mass; during the grinding process, or at the same time, the inert gas storage tank F1 is opened to allow the sealed grinding chamber B9, the grinding bin C2 and the grinding buffer chamber D10 to achieve an anti-oxidation environment that meets the requirements.

[0049] In this embodiment, specifically, firstly, the dry gas source, the inert gas storage tank F1 and the hot blast furnace are opened to heat the sealed grinding chamber B9 and the grinding buffer chamber D10. Then, a dry gas with a humidity of 12-18% is introduced into the sealed grinding chamber B9 and the grinding buffer chamber D10, and the dry gas pressure is 0.05Mpa. The sealed grinding chamber B9, the cyclone separator B5 and the blower B7 are opened to form an internal circulation wind, and the wind speed of the internal circulation wind is controlled at 6m / s. The sealed grinding chamber B9, the cyclone separator B5 and the blower B7 are opened to form an internal circulation wind, and then the calcium carbide catalyst with a particle size of about 15mm in the silo, the calcined white with a particle size of about 25mm in the silo, and the coke with a particle size of about 20mm in the silo are added to the feed hopper B1 for grinding, and the powder is ground to about 90 meshes; the grinding process also plays a role of pre-mixing, which can reduce the moisture absorption of the subsequent formal mixing process.

[0050] During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05MPa, the speed of the second sealed screw conveyor is: 2500r / min, the oil pump pressure between the two ball pressing rollers is: 15MPa, and the line pressure between the two ball pressing rollers is: 18t / cm.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst-doped magnesium raw material grinding and pelletizing system, characterized in that: It includes a grinding mechanism, a ball pressing mechanism and a dry gas protection mechanism; The grinding mechanism comprises a grinding mill body, a cyclone separator, a blower, and a grinding mill bin. A first sealed screw conveyor is provided at a feed inlet on one side of the grinding mill body, one to three feed hoppers are provided at the feed end of the first sealed screw conveyor, and a sealed discharger is provided at the discharge end of each feed hopper; The inside of the mill body is a sealed grinding chamber, the top of the sealed grinding chamber is connected to the inlet end of the cyclone separator through a first pipe, the top air outlet of the cyclone separator is connected to the blower through a second pipe, and the air outlet of the blower is connected to the bottom of the sealed grinding chamber through a third pipe, so that internal circulating wind is formed between the sealed grinding chamber, the cyclone separator and the blower, the discharge end of the cyclone separator is connected to the grinding bin through a fourth pipe, and a closed discharger is provided at the discharge end of the cyclone separator; The ball pressing mechanism comprises a ball pressing machine body, a second sealed screw conveyor is arranged on the ball pressing machine body, a grinding buffer chamber is arranged in the ball pressing machine body, a gas overflow port is arranged on the grinding buffer chamber, a ball pressing roller pair is arranged below the grinding buffer chamber, a ball pressing finished product outlet is arranged below the ball pressing roller pair, and a grinding bin is connected to the second sealed screw conveyor through a sealed lifting pipeline; The dry gas protection mechanism comprises a dry gas source, a gas outlet of the dry gas source is connected to a first main ventilation pipe, three first branch ventilation pipes are arranged on the first main ventilation pipe, one of the first branch ventilation pipes is connected to a first sealed screw conveyor, another first branch ventilation pipe is connected to a powder grinding bin, and the third first branch ventilation pipe is connected to a second sealed screw conveyor; A first pressure sensor and a humidity sensor are installed in the sealed grinding chamber and the grinding bin, and a first electromagnetic valve and a first gas flow meter are installed on the three first branch ventilation pipes; according to the monitoring data of the first pressure sensor, the amount and flow rate of the dry gas entering the sealed grinding chamber, the grinding bin and the grinding buffer chamber are controlled in real time through the first electromagnetic valve and the first gas flow meter to ensure that the sealed grinding chamber, the grinding bin and the grinding buffer chamber have a dry gas environment that meets the requirements.

2. The catalyst-doped magnesium raw material grinding and pelletizing system according to claim 1 is characterized in that: A bag dust collector is also provided, a fourth pipe is connected between the air inlet end of the bag dust collector and the third pipe, a second electromagnetic valve is installed on the fourth pipe, the discharge end of the bag dust collector is connected to the grinding bin through a fifth pipe, a closed discharger is provided at the discharge end of the bag dust collector, and the air outlet end of the bag dust collector is discharged to the outside after treatment; A second pressure sensor is installed on the fourth pipeline, and a second gas flow meter is installed on the second pipeline. The air volume and internal pressure of the internal circulation air are controlled in real time according to the detection data of the second pressure sensor and the second gas flow meter.

3. The catalyst-doped magnesium raw material grinding and pelletizing system according to claim 1 or 2, characterized in that: It also includes an inert gas storage tank, the outlet end of the inert gas storage tank is connected to a second main ventilation pipe, and three second branch ventilation pipes are arranged on the second main ventilation pipe, one of the second branch ventilation pipes is connected to the sealed grinding chamber, another second branch ventilation pipe is connected to the grinding bin, and the third second branch ventilation pipe is connected to the grinding buffer chamber, and a third electromagnetic valve and a third gas flow meter are installed on the three second branch ventilation pipes; the third electromagnetic valve and the third gas flow meter are used to control the amount and flow rate of dry gas entering the sealed grinding chamber, the grinding bin and the grinding buffer chamber in real time to ensure that the sealed grinding chamber, the grinding bin and the grinding buffer chamber have a dry and low-oxygen gas environment that meets the requirements.

4. The catalyst-doped magnesium raw material grinding and pelletizing system according to claim 3 is characterized in that: A hot air furnace is also provided, and a hot air duct is connected between the hot air furnace and the sealed grinding chamber and the grinding buffer chamber. A fourth electromagnetic valve and a fourth gas flow meter are provided on the hot air duct. According to the monitoring data of the humidity sensors in the sealed grinding chamber and the grinding buffer chamber, the amount and flow rate of hot air entering the sealed grinding chamber and the grinding buffer chamber are controlled in real time through the fourth electromagnetic valve and the fourth gas flow meter to ensure that the sealed grinding chamber and the grinding buffer chamber reach the required dryness and temperature environment.

5. A method for grinding and briquetting using the grinding and briquetting system according to any one of claims 1 to 4, characterized in that: The calcium carbide catalyst and magnesium smelting raw materials are ground and pre-mixed separately before pelletizing: Adding calcium carbide catalyst and magnesium smelting raw material into two feed hoppers respectively, grinding the calcium carbide catalyst and magnesium smelting raw material respectively, the particle size of calcium carbide catalyst after grinding is ≥100 mesh, and the particle size of magnesium smelting raw material is ≥120 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, grinding bin and grinding buffer chamber reach the required dry gas environment, the humidity is less than 20%, and the dry gas pressure is 0.05~0.15Mpa; the wind speed of the internal circulation air formed between the sealed grinding chamber, cyclone separator and blower is controlled at 3~25m / s; After the grinding is completed, the powder is pre-mixed in the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

6. The method for grinding and briquetting according to claim 5, characterized in that: The calcium carbide catalyst and the magnesium smelting raw material are ground and mixed in a mass ratio of 35%±5%:35%±5%; during the grinding and ball pressing process, or by opening the inert gas storage tank at the same time, the sealed grinding chamber, the grinding bin, and the grinding buffer chamber are allowed to achieve an anti-oxidation environment that meets the requirements.

7. A method for grinding and briquetting using the grinding and briquetting system according to any one of claims 1 to 4, characterized in that: The calcium carbide catalyst and magnesium smelting raw materials are pre-mixed, then ground and finally pelletized: Add the calcium carbide catalyst and the magnesium smelting raw material into the feed hopper, and enter the sealed grinding chamber through the first sealed screw conveyor for premixing, and then grind the mixture of the two, and the particle size of the mixture after grinding is ≥80 mesh, preferably ≥100 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, the grinding bin, and the grinding buffer chamber reach a dry gas environment that meets the requirements, with a humidity of less than 20%, a dry gas pressure of 0.05-0.15 MPa, and the wind speed of the internal circulation wind formed between the sealed grinding chamber, the cyclone separator, and the blower is controlled at 3-25 m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

8. The method for grinding and briquetting according to claim 7, characterized in that: The calcium carbide catalyst and the magnesium smelting raw material are ground and mixed in a mass ratio of 35%±5%:35%±5%; during the grinding process, or at the same time, the inert gas storage tank is opened to allow the sealed grinding chamber, the grinding bin, and the grinding buffer chamber to achieve an anti-oxidation environment that meets the requirements.

9. A method for grinding and briquetting using the grinding and briquetting system according to any one of claims 1 to 4, characterized in that: The calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent are pre-mixed at the same time, then ground and finally pressed into balls: Adding calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent into the feed hopper, all three enter the sealed grinding chamber through the first sealed screw conveyor for premixing, and then grind the mixture of the three, and the particle size of the mixture after grinding is ≥80 mesh; during the grinding process, the dry gas source is always turned on to make the sealed grinding chamber, the grinding bin and the grinding buffer chamber reach the required dry gas environment, the humidity is less than 20%, the dry gas pressure is 0.05~0.15MPa, and the wind speed of the internal circulation air formed between the sealed grinding chamber, the cyclone separator and the blower is controlled at 3~25m / s; After the grinding is completed, it enters the grinding bin and then enters the ball pressing mechanism for ball pressing; During the ball pressing process, the gas outlet pressure of the gas overflow port is: 0.05~0.15MPa. At the same time, the linear pressure of the grinding powder on the ball pressing rollers is controlled by adjusting the speed of the second sealed screw conveyor and the oil pump pressure between the two ball pressing rollers. Among them, the speed of the second sealed screw conveyor is: 750r / min~3000r / min, the oil pump pressure between the two ball pressing rollers is: 10~30MPa, and the linear pressure between the two ball pressing rollers is: 5t / cm~20t / cm.

10. The method for grinding and briquetting according to claim 9, characterized in that: The mixing ratio of the calcium carbide catalyst, magnesium smelting raw material and carbon reducing agent is 35%±4%:35%±4%:30%±2% by mass; during the grinding process, or opening the inert gas storage tank at the same time, the sealed grinding chamber, grinding bin and grinding buffer chamber can achieve an anti-oxidation environment that meets the requirements.

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