A preparation process based on high-purity magnesium oxide

Abstract

This invention discloses a process for preparing high-purity magnesium oxide, comprising the following steps: A: Crushing: Mined magnesite ore is fed into a crusher, and the crushed magnesite ore enters a conveyor belt and is conveyed into a grinding mill; B: Grinding and Screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier operates to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for re-grinding, and this process is repeated; C: Calcination: Qualified magnesite ore powder is calcined. This invention, through the combined use of the above processes, offers advantages such as minimal waste generation and low production costs in the preparation of high-purity magnesium oxide. Using magnesite ore as the raw material for preparing high-purity magnesium oxide avoids the generation of large amounts of reaction materials, thus reducing the production cost of high-purity magnesium oxide.

Description

Technical Field

[0001] This invention relates to the field of high-purity magnesium oxide preparation technology, specifically to a high-purity magnesium oxide preparation process. Background Technology

[0002] High-purity magnesium oxide exhibits excellent alkali resistance and electrical insulation at high temperatures, as well as good light transmittance, making it a frequently used high-temperature heat-resistant material. In the ceramics industry, it is used as a raw material for translucent ceramic crucibles and substrates, while in the electrical industry, it is used as filler in magnetic devices, insulating materials, and various carriers.

[0003] Patent application publication number CN116119694A discloses a process for preparing high-purity magnesium oxide. The cleaning device described in step one includes a shell and an inner liner that rotates within the shell. A mounting base is located at the bottom of the inner liner. This invention relates to the field of magnesium oxide preparation technology. This high-purity magnesium oxide preparation process uses a driving device to continuously rotate the mounting base, causing the magnesium chloride on the filter screen to agitate slightly. This ensures sufficient contact between the magnesium chloride and concentrated hydrochloric acid, enhancing the cleaning effect. Simultaneously, the engagement of the locking pins and holes overcomes the friction between the inner liner and the mounting base and the friction pads. The cleaning process can be automatically stopped without stopping the driving device, automatically draining the concentrated hydrochloric acid and achieving a mechanical timing effect. Combined with fixing the filter screen after raising its rotation angle, this drains the concentrated hydrochloric acid, ensuring that minimal residual concentrated hydrochloric acid remains on the surface of the magnesium chloride when it is subsequently removed.

[0004] However, the above-mentioned device still has some drawbacks in actual use. The most obvious one is that a large amount of waste is generated in the process of preparing high-purity magnesium oxide using magnesium chloride. If this waste is not treated in time, it will cause great pollution to the surrounding environment. At the same time, the preparation of high-purity magnesium oxide using magnesium chloride requires the consumption of a large amount of concentrated hydrochloric acid, dispersing emulsifier, ammonia water and ammonium bicarbonate, which increases the cost of producing high-purity magnesium oxide and is not conducive to large-scale production.

[0005] Therefore, it is necessary to invent a high-purity magnesium oxide preparation process to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a high-purity magnesium oxide preparation process that has the advantages of not generating a large amount of waste and having low preparation cost. It solves the problems of generating a large amount of waste and causing significant pollution to the surrounding environment when using magnesium chloride to prepare high-purity magnesium oxide, and the need to consume a large amount of materials, which increases the cost of producing high-purity magnesium oxide.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a process for preparing high-purity magnesium oxide, comprising the following steps:

[0008] A: Crushing: The mined magnesite ore is fed into the crusher, and the crushed magnesite ore enters the conveyor belt and is conveyed into the grinding mill.

[0009] B: Grinding and screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier is running to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for grinding again, and this process is repeated.

[0010] C: Calcination: Magnesite ore powder that has passed the air separation is fed into the calcination furnace through the operation of the zipper machine. During the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide.

[0011] D: Heating and hydrolysis: The obtained magnesium carbide is passed into a hydrolysis tank, and after hydrolysis, magnesium hydroxide and propyne are obtained;

[0012] E: Drying: Take out the water-insoluble magnesium hydroxide and put it into a drying oven for drying. During drying, the magnesium hydroxide is evenly spread at the bottom of the drying oven cavity, with a thickness of 1-3cm.

[0013] F: Calcination: Take out the solid magnesium hydroxide from the drying furnace, transfer it to a crucible, heat it, and calcine it to obtain the product magnesium oxide.

[0014] Preferably, in step A, the particle size of the crushed magnesite ore is 5-100mm, and the conveyor belt has a conveying capacity of 10-30T / h.

[0015] Preferably, in step B, the grinding mill rotates at a speed of 300-600 r / min, the air velocity in the air classifier is 70-90 m / s, and the particle size of the magnesite powder is 30-100 micrometers.

[0016] Preferably, the calcination temperature in step C is 900-1100℃, and the carbon dioxide is added at a uniform rate, without excessive or insufficient flow.

[0017] Preferably, in step D, the generated propyne is collected and used as a fuel component in the calcination furnace. During the hydrolysis of magnesium carbide, sodium hydroxide solution is added, and the sodium hydroxide solution reacts with magnesium carbide to produce sodium chloride, which is dissolved in water.

[0018] Preferably, the drying temperature of magnesium hydroxide in step E is 140-160℃, the drying time of magnesium hydroxide is 2-4h, and the water vapor generated during the drying process is collected and cooled.

[0019] Preferably, the calcination temperature of magnesium hydroxide in step F is 350-380°C, and the magnesium hydroxide is repeatedly stirred during the calcination process.

[0020] Preferably, the magnesium hydroxide is stirred at a speed of 15-20 r / min for a duration of 20-30 min.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention, through the combined use of the above processes, has the advantages of not generating a large amount of waste and having low production costs in the process of preparing high-purity magnesium oxide. By using magnesite ore as the raw material for preparing high-purity magnesium oxide, a large amount of reaction raw materials are not generated, thus reducing the production cost of high-purity magnesium oxide. Detailed Implementation

[0023] Please refer to a process for preparing high-purity magnesium oxide, which includes the following steps:

[0024] A: Crushing: The mined magnesite ore is fed into the crusher, and the crushed magnesite ore enters the conveyor belt and is conveyed into the grinding mill.

[0025] B: Grinding and screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier is running to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for grinding again, and this process is repeated.

[0026] C: Calcination: Magnesite ore powder that has passed the air separation is fed into the calcination furnace through the operation of the zipper machine. During the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide.

[0027] D: Heating and hydrolysis: The obtained magnesium carbide is passed into a hydrolysis tank. After hydrolysis, magnesium hydroxide and propyne are obtained. Magnesium hydroxide is an inorganic substance with the chemical formula Mg(OH)2. It is a white amorphous powder or colorless hexagonal prism crystal. It is soluble in dilute acid and ammonium salt solutions, almost insoluble in water. The part that is soluble in water is completely ionized, and the aqueous solution is weakly alkaline.

[0028] E: Drying: Take out the water-insoluble magnesium hydroxide and put it into a drying oven for drying. During drying, the magnesium hydroxide is evenly spread at the bottom of the drying oven cavity, with a thickness of 1-3cm.

[0029] F: Calcination: Take out the solid magnesium hydroxide from the drying furnace after drying, transfer it to a crucible, heat it, and calcine it to obtain the product magnesium oxide.

[0030] In step A, the particle size of the crushed magnesite is 5-100mm, and the conveyor belt conveyor capacity is 10-30T / h.

[0031] In step B, the grinding mill rotates at 300-600 r / min, the air velocity in the air classifier is 70-90 m / s, and the particle size of the magnesite powder is 30-100 micrometers.

[0032] In step C, the calcination temperature is 900-1100℃, and the carbon dioxide is added at a uniform rate, without the flow rate being too high or too low.

[0033] In step D, the generated propyne is collected and used as a fuel component in the calcination furnace. During the hydrolysis of magnesium carbide, sodium hydroxide solution is added. The sodium hydroxide solution reacts with magnesium carbide to produce sodium chloride, which dissolves in water.

[0034] In step E, the drying temperature of magnesium hydroxide is 140-160℃, the drying time of magnesium hydroxide is 2-4h, and the water vapor generated during the drying process is collected and cooled.

[0035] In step F, the calcination temperature of magnesium hydroxide is 350-380℃, and the magnesium hydroxide is stirred repeatedly during the calcination process.

[0036] The stirring speed for magnesium hydroxide is 15-20 r / min, and the stirring time is 20-30 min.

[0037] The present invention, through the combined use of the above processes, has the advantages of not generating a large amount of waste and having low production costs in the process of preparing high-purity magnesium oxide. By using magnesite ore as the raw material for preparing high-purity magnesium oxide, a large amount of reaction raw materials are not generated, thus reducing the production cost of high-purity magnesium oxide.

[0038] Example 1:

[0039] A process for preparing high-purity magnesium oxide includes the following steps:

[0040] A: Crushing: The mined magnesite ore is fed into the crusher, and the crushed magnesite ore enters the conveyor belt and is conveyed into the grinding mill.

[0041] B: Grinding and screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier is running to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for grinding again, and this process is repeated.

[0042] C: Calcination: Magnesite ore powder that has passed the air separation is fed into the calcination furnace through the operation of the zipper machine. During the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide.

[0043] D: Heating and hydrolysis: The obtained magnesium carbide is passed into a hydrolysis tank. After hydrolysis, magnesium hydroxide and propyne are obtained. Magnesium hydroxide is an inorganic substance with the chemical formula Mg(OH)2. It is a white amorphous powder or colorless hexagonal prism crystal. It is soluble in dilute acid and ammonium salt solutions, almost insoluble in water. The part that is soluble in water is completely ionized, and the aqueous solution is weakly alkaline.

[0044] E: Drying: Take out the water-insoluble magnesium hydroxide and put it into a drying oven for drying. During drying, the magnesium hydroxide is evenly spread at the bottom of the drying oven cavity with a thickness of 1cm.

[0045] F: Calcination: Take out the solid magnesium hydroxide from the drying furnace after drying, transfer it to a crucible, heat it, and calcine it to obtain the product magnesium oxide.

[0046] In step A, the particle size of the crushed magnesite ore is 5mm, and the conveyor belt conveyor capacity is 10T / h.

[0047] In step B, the grinding mill rotates at 300 r / min, the air velocity in the air classifier is 70 m / s, and the particle size of the magnesite powder is 30 micrometers.

[0048] In step C, the calcination temperature is 900℃. During the addition of carbon dioxide, the addition process is uniform, and there will be no situation where the flow rate is too large or too small.

[0049] In step D, the generated propyne is collected and used as a fuel component in the calcination furnace. During the hydrolysis of magnesium carbide, sodium hydroxide solution is added. The sodium hydroxide solution reacts with magnesium carbide to produce sodium chloride, which dissolves in water.

[0050] In step E, the drying temperature of magnesium hydroxide is 140℃ and the drying time is 2 hours. The water vapor generated during the drying process is collected and cooled.

[0051] In step F, the calcination temperature of magnesium hydroxide is 350℃, and the magnesium hydroxide is stirred repeatedly during the calcination process.

[0052] The magnesium hydroxide was stirred at a speed of 15 r / min for 20 min.

[0053] The present invention, through the combined use of the above processes, has the advantages of not generating a large amount of waste and having low production costs in the process of preparing high-purity magnesium oxide. By using magnesite ore as the raw material for preparing high-purity magnesium oxide, a large amount of reaction raw materials are not generated, thus reducing the production cost of high-purity magnesium oxide.

[0054] Example 2:

[0055] A process for preparing high-purity magnesium oxide includes the following steps:

[0056] A: Crushing: The mined magnesite ore is fed into the crusher, and the crushed magnesite ore enters the conveyor belt and is conveyed into the grinding mill.

[0057] B: Grinding and screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier is running to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for grinding again, and this process is repeated.

[0058] C: Calcination: Magnesite ore powder that has passed the air separation is fed into the calcination furnace through the operation of the zipper machine. During the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide.

[0059] D: Heating and hydrolysis: The obtained magnesium carbide is passed into a hydrolysis tank. After hydrolysis, magnesium hydroxide and propyne are obtained. Magnesium hydroxide is an inorganic substance with the chemical formula Mg(OH)2. It is a white amorphous powder or colorless hexagonal prism crystal. It is soluble in dilute acid and ammonium salt solutions, almost insoluble in water. The part that is soluble in water is completely ionized, and the aqueous solution is weakly alkaline.

[0060] E: Drying: Take out the water-insoluble magnesium hydroxide and put it into a drying oven for drying. During drying, the magnesium hydroxide is evenly spread at the bottom of the drying oven cavity with a thickness of 2cm.

[0061] F: Calcination: Take out the solid magnesium hydroxide from the drying furnace after drying, transfer it to a crucible, heat it, and calcine it to obtain the product magnesium oxide.

[0062] In step A, the particle size of the crushed magnesite ore is 55mm, and the conveyor belt conveying capacity is 10-30T / h.

[0063] In step B, the grinding mill rotates at 450 r / min, the air velocity in the air classifier is 80 m / s, and the particle size of the magnesite powder is 65 micrometers.

[0064] In step C, the calcination temperature is 1000℃. During the addition of carbon dioxide, the addition process is uniform, and there will be no situation where the flow rate is too large or too small.

[0065] In step D, the generated propyne is collected and used as a fuel component in the calcination furnace. During the hydrolysis of magnesium carbide, sodium hydroxide solution is added. The sodium hydroxide solution reacts with magnesium carbide to produce sodium chloride, which dissolves in water.

[0066] In step E, the drying temperature of magnesium hydroxide is 150℃ and the drying time is 3 hours. The water vapor generated during the drying process is collected and cooled.

[0067] In step F, the calcination temperature of magnesium hydroxide is 365℃, and the magnesium hydroxide is stirred repeatedly during the calcination process.

[0068] The magnesium hydroxide was stirred at a speed of 17 r / min for 25 min.

[0069] The present invention, through the combined use of the above processes, has the advantages of not generating a large amount of waste and having low production costs in the process of preparing high-purity magnesium oxide. By using magnesite ore as the raw material for preparing high-purity magnesium oxide, a large amount of reaction raw materials are not generated, thus reducing the production cost of high-purity magnesium oxide.

[0070] Example 3:

[0071] A process for preparing high-purity magnesium oxide includes the following steps:

[0072] A: Crushing: The mined magnesite ore is fed into the crusher, and the crushed magnesite ore enters the conveyor belt and is conveyed into the grinding mill.

[0073] B: Grinding and screening: The magnesite ore is ground using grinding rollers. During the grinding process, an air classifier is running to classify the ground magnesite ore powder. Unqualified magnesite ore powder is returned to the grinding mill for grinding again, and this process is repeated.

[0074] C: Calcination: Magnesite ore powder that has passed the air separation is fed into the calcination furnace through the operation of the zipper machine. During the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide.

[0075] D: Heating and hydrolysis: The obtained magnesium carbide is passed into a hydrolysis tank. After hydrolysis, magnesium hydroxide and propyne are obtained. Magnesium hydroxide is an inorganic substance with the chemical formula Mg(OH)2. It is a white amorphous powder or colorless hexagonal prism crystal. It is soluble in dilute acid and ammonium salt solutions, almost insoluble in water. The part that is soluble in water is completely ionized, and the aqueous solution is weakly alkaline.

[0076] E: Drying: Take out the water-insoluble magnesium hydroxide and put it into a drying oven for drying. During drying, the magnesium hydroxide is evenly spread at the bottom of the drying oven cavity with a thickness of 3cm.

[0077] F: Calcination: Take out the solid magnesium hydroxide from the drying furnace after drying, transfer it to a crucible, heat it, and calcine it to obtain the product magnesium oxide.

[0078] In step A, the particle size of the crushed magnesite ore is 100mm, and the conveyor belt conveyor capacity is 30T / h.

[0079] In step B, the grinding mill rotates at 600 r / min, the air velocity of the air classifier is 90 m / s, and the particle size of the magnesite powder is 100 micrometers.

[0080] In step C, the calcination temperature is 1100℃. During the addition of carbon dioxide, the addition process is uniform, and there will be no situation where the flow rate is too large or too small.

[0081] In step D, the generated propyne is collected and used as a fuel component in the calcination furnace. During the hydrolysis of magnesium carbide, sodium hydroxide solution is added. The sodium hydroxide solution reacts with magnesium carbide to produce sodium chloride, which dissolves in water.

[0082] In step E, the drying temperature of magnesium hydroxide is 160℃ and the drying time is 4 hours. The water vapor generated during the drying process is collected and cooled.

[0083] In step F, the calcination temperature of magnesium hydroxide is 380℃, and the magnesium hydroxide is stirred repeatedly during the calcination process.

[0084] The magnesium hydroxide was stirred at a speed of 20 r / min for 30 min.

[0085] The present invention, through the combined use of the above processes, has the advantages of not generating a large amount of waste and having low production costs in the process of preparing high-purity magnesium oxide. By using magnesite ore as the raw material for preparing high-purity magnesium oxide, a large amount of reaction raw materials are not generated, thus reducing the production cost of high-purity magnesium oxide.

[0086] In summary, this invention, based on a high-purity magnesium oxide preparation process, solves the problems of generating large amounts of waste and causing significant environmental pollution during the preparation of high-purity magnesium oxide using magnesium chloride, and the increased cost of producing high-purity magnesium oxide due to the consumption of large amounts of materials.

Claims

1. A process for the preparation of high purity magnesium oxide based on which is characterized by It comprises the following steps: A: crushing: the mined magnesite is fed into a crusher, and the crushed magnesite is fed onto a conveying belt and then conveyed into a grinding machine; B: grinding and screening: the magnesite is ground by a grinding roller, and during the grinding process, an air separator is operated to air separate the ground magnesite powder, and the unqualified magnesite powder is returned to the grinding machine for regrinding; C: calcination: the qualified magnesite powder is fed into a calcination furnace through the operation of a zipper machine, and during the calcination process, carbon dioxide is introduced into the calcination furnace for carbonization treatment to form magnesium carbide; D: heating and hydrolysis: the obtained magnesium carbide is introduced into a hydrolysis tank, and after hydrolysis, magnesium hydroxide and propyne are obtained; E: drying: the water-insoluble magnesium hydroxide is taken out and placed in a drying furnace for drying treatment, and during the drying process, the magnesium hydroxide is evenly laid on the bottom of the drying furnace cavity, and the thickness of the laying is 1-3 cm; F: calcination: the dried magnesium hydroxide solid is taken out and transferred to a crucible for heating and calcination treatment, and the calcination product is magnesium oxide.

2. The process for preparing high purity magnesium oxide according to claim 1, characterized in that: In step A, the particle size of the crushed magnesite is 5-100 mm, and the conveying capacity of the conveying belt is 10-30 T / h.

3. The process for preparing high purity magnesium oxide according to claim 1, characterized in that: In step B, the rotating speed of the grinding machine is 300-600 r / min, the air speed of the air separation is 70-90 m / s, and the particle size of the magnesite powder is 30-100 microns.

4. The process for preparing high purity magnesium oxide according to claim 1, characterized in that: In step C, the calcination temperature is 900-1100℃, and during the addition of carbon dioxide, the addition process is uniform, and there is no condition of excessive or insufficient flow.

5. The process for preparing high purity magnesium oxide according to claim 1, wherein: In step E, the drying temperature of the magnesium hydroxide is 140-160℃, the drying time of the magnesium hydroxide is 2-4 h, and the water vapor generated during the drying process is collected and cooled.

6. The process for preparing high purity magnesium oxide according to claim 1, wherein: In step F, the calcination temperature of the magnesium hydroxide is 350-380℃, and the magnesium hydroxide is repeatedly stirred during the calcination process.

7. The process for preparing high purity magnesium oxide according to claim 6, wherein: The stirring speed of the magnesium hydroxide is 15-20 r / min, and the stirring time is 20-30 min.