Superfine high-purity calcium oxide and preparation process thereof

Abstract

The invention relates to the technical field of inorganic non-metallic material preparation, in particular to superfine high-purity calcium oxide which has the purity of more than or equal to 99.2 wt%, the particle size D50 of less than or equal to 500nm, the total impurity content of less than or equal to 0.8 wt% and the specific surface area of more than or equal to 15.2 m < 2 > / g. The impurity is a mixture of silicon, iron and magnesium. According to the method, in the raw material pretreatment stage, a mode of combining fine crushing and activating treatment is adopted, so that the reaction activity of the raw materials is greatly improved, a good foundation is provided for subsequent roasting decomposition, and efficient proceeding of a subsequent process is ensured. And secondly, by optimizing atmosphere selection, heating rate and heat preservation mode in the roasting process, full decomposition of the raw materials is realized, effective removal of impurities is promoted, overgrowth of crystal grains is avoided, and a core foundation is laid for improvement of product performance. A plurality of efficient treatment means are integrated in the post-treatment link, so that the particle aggregation phenomenon is effectively eliminated, residual impurities can be accurately removed, the particle size of the product is further refined, and the purity of the product is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inorganic non-metallic material preparation, and particularly discloses superfine high-purity calcium oxide and a preparation process thereof. BACKGROUND

[0002] Calcium oxide, as an important inorganic non-metallic material, is widely used in chemical industry, building materials, environmental protection, medicine and other fields. With the rapid development of high-end manufacturing industry, the market puts forward more stringent requirements on the performance of calcium oxide products. Not only is a finer particle size required to improve dispersibility and reaction efficiency, but also a higher purity is required to avoid the adverse effects of impurities on application results.

[0003] However, the existing calcium oxide preparation process has many deficiencies, which restricts the improvement of product performance. In the raw material processing link, the traditional process often uses ordinary crushing equipment, and the raw material is not refined enough, and there is no effective activation treatment, which leads to low reactivity of the raw material and difficulty in subsequent decomposition process. In terms of calcination process, the existing technology often uses single temperature calcination, the heating mode is unreasonable, the atmosphere control is not precise enough, and problems such as incomplete decomposition of calcium carbonate or excessive growth of crystal grains are prone to occur, and the impurity removal effect is not good. The post-processing link is generally single, relying only on simple crushing treatment, which cannot effectively break the particle agglomeration phenomenon, and it is also difficult to accurately remove the impurities remaining in the production process, resulting in the final product having a large particle size, insufficient purity, small specific surface area and low reactivity. In addition, some existing improved processes still have obvious defects, for example, when using template method for preparation, the template is easy to leave impurities after pyrolysis, affecting the purity of the product; the double-chamber kiln calcination process still has room for improvement in purity control and particle size refinement. Overall, the existing process lacks systematic and coordinated optimization, and the cooperation between the links is not reasonable enough, which makes it difficult for the calcium oxide product to meet the application requirements of high-end fields, limiting the further expansion of its application range. SUMMARY

[0004] The primary object of the present application is to provide a superfine high-purity calcium oxide and a preparation process thereof.

[0005] A further object of the present application is to provide a superfine high-purity calcium oxide with a purity of ≥99.2wt%, a particle size D50≤500nm, a total impurity content of ≤0.8wt%, and a specific surface area of ≥15.2m 2 / g.

[0006] Preferably, the purity of the calcium oxide is ≥99.5wt%, the particle size D50≤300nm, the total impurity content is ≤0.5wt%, and the specific surface area is ≥22.5m 2 / g.

[0007] Preferably, the calcium oxide has a purity ≥ 99.7 wt%, a particle size D50 ≤ 200 nm, a total impurity content ≤ 0.3 wt%, and a specific surface area ≥ 30.8 m². 2 / g.

[0008] Preferably, the calcium oxide has a purity ≥ 99.9 wt%, a particle size D50 ≤ 100 nm, a total impurity content ≤ 0.1 wt%, and a specific surface area ≥ 40.1 m². 2 / g.

[0009] Preferably, the hydration time of the calcium oxide is ≤30 min.

[0010] A process for preparing the ultrafine, high-purity calcium oxide includes the following steps:

[0011] (1) Raw material pretreatment: Take calcium carbonate raw materials, crush them, add deionized water and stir to form a slurry, filter after stirring, dry the solid obtained by filtration to obtain pretreated calcium carbonate;

[0012] (2) Calcination: Pretreated calcium carbonate is placed in a muffle furnace, heated to a preset temperature at a preset heating rate under a preset atmosphere and held at the preset temperature, and then cooled to room temperature to obtain crude calcium oxide.

[0013] (3) Post-processing: The crude calcium oxide is pulverized to obtain ultrafine high-purity calcium oxide product.

[0014] Preferably, in step (1), the calcium carbonate raw material is at least one of calcite, marble, or light calcium carbonate, and the purity of the calcium carbonate raw material is ≥98.5wt%; the particle size of the raw material after crushing is ≤10μm; the solid-liquid ratio when adding deionized water is 1:2-1:5; an activator is also added during the stirring process, and the activator is at least one of citric acid, stearic acid, or citric acid-stearic acid composite activator, and the amount of activator added is 0.3wt%-0.8wt% of the mass of the calcium carbonate raw material; the stirring temperature is 30℃-50℃, the stirring time is 30min-75min; the drying temperature is 105℃-120℃, and the drying time is 0.5h-2h.

[0015] Preferably, in step (2), the preset atmosphere is one of air, nitrogen or argon; when the preset atmosphere is nitrogen, the nitrogen flow rate is 2L / min; when the preset atmosphere is argon, the argon flow rate is 3L / min; the preset heating rate is 8℃ / min-12℃ / min; the preset temperature is 850℃-1000℃, and the holding time is 2h-3h.

[0016] Preferably, in step (2), the step of baking is carried out in stages: first, the temperature is raised to 600 DEG C at a rate of 8 DEG C / min and maintained for 1 h, and then the temperature is raised to 1000 DEG C at a rate of 10 DEG C / min and maintained for 2 h.

[0017] Preferably, in step (3), the crude calcium oxide is subjected to ultrasonic treatment before being crushed, the power of the ultrasonic treatment is 500 W-800 W, and the treatment time is 30 min-50 min; after the ultrasonic treatment, dilute hydrochloric acid is added and stirred, the mass fraction of the dilute hydrochloric acid is 5%, the amount of the dilute hydrochloric acid added is 0.5 wt% of the mass of the crude calcium oxide, and the stirring time is 15 min; after the stirring, the solid obtained by filtration is washed with deionized water until neutral, then dried at 110 DEG C for 1 h, and finally crushed.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1. In the raw material pretreatment stage, the present application combines fine crushing with activation treatment, greatly improving the reactivity of the raw material, providing a good foundation for subsequent calcination and decomposition, and ensuring the efficient operation of the subsequent process. Secondly, the calcination process optimizes the atmosphere selection, heating rate and holding method, achieving the full decomposition of the raw material, promoting the effective removal of impurities, and avoiding excessive grain growth, laying the foundation for improving product performance. The post-treatment process integrates multiple efficient treatment methods, not only effectively breaking the particle agglomeration phenomenon, but also accurately removing residual impurities, further refining the product particle size and improving the product purity.

[0020] 2. Through multi-link synergistic improvement, the product purity is greatly improved, the impurity content is significantly reduced, and the high-end field requirements for high purity are met; the particle size is significantly refined, the dispersibility is better, and the reaction contact area is effectively increased; the specific surface area is greatly improved, providing structural support for the enhancement of reactivity, making the product hydration rate faster and the reactivity significantly improved. Compared with traditional processes and existing improved processes, the present application does not rely on special materials such as templates, avoiding the problem of residual impurities, and has significant advantages in purity control, particle size refinement, activity improvement and impurity removal.

[0021] 3. The process parameters of the present application are easy to control, and can be flexibly adjusted according to the needs of different application scenarios, such as raw material specifications, calcination conditions and post-treatment methods, to realize precise customization of product performance, adapt to diversified high-end needs such as precision chemical catalysis, high-end pharmaceutical excipients and electronic-grade ceramic raw materials. At the same time, the overall process is simple and efficient, without the need to introduce expensive equipment or special reagents, balancing performance advantages and production cost control, providing a feasible path for industrial large-scale production, and promoting the expansion of calcium oxide materials to high-value-added fields. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Embodiment 1:

[0024] (1) Raw material pretreatment stage: take calcite with a purity of 98.5wt%, use a superfine pulverizer to crush it to a particle size of 10μm, add deionized water in a solid-liquid ratio of 1:5 and stir to form a slurry, continue stirring for 30 minutes, then perform filtration operation, and dry the obtained solid at 105℃ for 2 hours to obtain pretreated calcium carbonate. No activator is added in this embodiment.

[0025] (2) Calcination stage: put the pretreated calcium carbonate into a muffle furnace, use air atmosphere, and heat to 850℃ at a heating rate of 10℃ / min, keep the temperature for 2 hours, then naturally cool to room temperature to obtain crude calcium oxide.

[0026] (3) Post-treatment stage: use a superfine pulverizer to crush the crude calcium oxide to a particle size of 500nm. No additional impurity removal operation is performed in this stage, and finally the superfine calcium oxide product is obtained.

[0027] Embodiment 2:

[0028] (1) Raw material pretreatment stage: take marble with a purity of 99.2wt%, use a superfine pulverizer to crush it to a particle size of 5μm, add deionized water in a solid-liquid ratio of 1:4 and stir to form a slurry, add 0.3wt% of citric acid based on the mass of marble, and continuously stir at 30℃ for 45 minutes. After stirring, perform filtration operation, and dry the obtained solid at 110℃ for 1.5 hours to obtain pretreated calcium carbonate.

[0029] (2) Calcination stage: put the pretreated calcium carbonate into a muffle furnace, use air atmosphere, and heat to 900℃ at a heating rate of 8℃ / min, keep the temperature for 2.5 hours, then naturally cool to room temperature to obtain crude calcium oxide.

[0030] (3) Post-treatment stage: first use an ultrasonic pulverizer with a power of 500W to treat the crude calcium oxide for 30 minutes, then use a superfine pulverizer to crush it to a particle size of 300nm, and finally obtain the superfine calcium oxide product.

[0031] Embodiment 3:

[0032] (1) Raw material pretreatment stage: take the light calcium carbonate with a purity of 99.5wt%, use the superfine pulverizer to crush it to a particle size of 2μm, add deionized water in a solid-liquid ratio of 1:3 and stir to form a slurry, add 0.6wt% of stearic acid based on the mass of light calcium carbonate, continuously stir at 40℃ for 60 minutes, after stirring, filter the solid, and dry the solid at 115℃ for 1 hour, to obtain pretreated calcium carbonate.

[0033] (2) Calcination stage: put the pretreated calcium carbonate into a muffle furnace, use nitrogen atmosphere and nitrogen flow of 2L / min, heat to 950℃ at a heating rate of 12℃ / min, keep the temperature for 3 hours, then naturally cool to room temperature, to obtain crude calcium oxide.

[0034] (3) Post-treatment stage: first use an ultrasonic pulverizer with a power of 600W to treat the crude calcium oxide for 40 minutes, then use a superfine pulverizer to crush it to a particle size of 200nm, finally obtain the superfine calcium oxide product.

[0035] Example 4:

[0036] (1) Raw material pretreatment stage: take the light calcium carbonate with a purity of 99.9wt%, use the superfine pulverizer to crush it to a particle size of 1μm, add deionized water in a solid-liquid ratio of 1:2 and stir to form a slurry, add 0.8wt% of citric acid-stearic acid composite activator based on the mass of light calcium carbonate, continuously stir at 50℃ for 75 minutes, after stirring, filter the solid, and dry the solid at 120℃ for 0.5 hours, to obtain pretreated calcium carbonate.

[0037] (2) Calcination stage: put the pretreated calcium carbonate into a muffle furnace, use argon atmosphere and argon flow of 3L / min, use a step-by-step calcination method: first heat to 600℃ at a heating rate of 8℃ / min and keep the temperature for 1 hour, then heat to 1000℃ at a heating rate of 10℃ / min and keep the temperature for 2 hours, then naturally cool to room temperature, to obtain crude calcium oxide.

[0038] (3) Post-treatment stage: first use an ultrasonic pulverizer with a power of 800W to treat the crude calcium oxide for 50 minutes, then add 5% of dilute hydrochloric acid based on the mass of crude calcium oxide, continuously stir for 15 minutes, after stirring, filter the solid, wash the solid with deionized water until neutral, dry the solid at 110℃ for 1 hour, finally use a superfine pulverizer to crush it to a particle size of 100nm, to obtain the superfine calcium oxide product.

[0039] Comparative Example 1:

[0040] (1) Raw material pretreatment stage: take calcite with purity of 98.5wt%, use ordinary pulverizer to crush it to particle size of 50μm, wash with deionized water and dry at 105℃ for 2 hours to obtain pretreated calcium carbonate. No activator is added in this comparative example.

[0041] (2) Calcination stage: use air atmosphere, heat to 850℃ at a heating rate of 10℃ / min and keep for 2 hours. The rest of the operation is consistent with the calcination stage of example 1.

[0042] (3) Post-treatment stage: only use ordinary pulverizer to crush the crude calcium oxide, without ultrasonic treatment, finally obtain calcium oxide product.

[0043] Comparative example 2:

[0044] (1) The operation of raw material pretreatment stage is completely consistent with example 2, that is, take marble with purity of 99.2wt%, crush to particle size of 5μm, prepare slurry according to solid-liquid ratio of 1:4, add 0.3wt% citric acid and stir for 45 minutes, filter and dry at 110℃ for 1.5 hours.

[0045] (2) Calcination stage: use air atmosphere, heat to 700℃ at a heating rate of 8℃ / min and keep for 2.5 hours. The rest of the operation is consistent with the calcination stage of example 2.

[0046] (3) The operation of post-treatment stage is completely consistent with example 2, that is, first ultrasonic treatment at 500W for 30 minutes, then crush to particle size of 300nm, finally obtain calcium oxide product.

[0047] Comparative example 3:

[0048] (1) Raw material pretreatment stage: take calcite with purity of 97.0wt%, use superfine pulverizer to crush it to particle size of 10μm, without adding activator, dry at 105℃ for 2 hours to obtain pretreated calcium carbonate.

[0049] (2) The operation of calcination stage is completely consistent with example 1, that is, air atmosphere, heat to 850℃ at a heating rate of 10℃ / min and keep for 2 hours.

[0050] (3) Post-treatment stage: only use ordinary pulverizer to crush the crude calcium oxide to particle size of 1000nm, without acid washing operation, finally obtain calcium oxide product.

[0051] Comparative example 4:

[0052] (1) The operation of the raw material pretreatment stage is completely consistent with that of Example 4, that is, taking light calcium carbonate with a purity of 99.9wt%, crushing to a particle size of 1 μm, preparing slurry at a solid-liquid ratio of 1:2, adding 0.8wt% of a composite activator and stirring for 75 minutes, filtering, and drying at 120°C for 0.5 hours.

[0053] (2) The calcination stage: under an argon atmosphere, the temperature is directly raised to 1000°C at a rate of 10°C / min and kept for 3 hours without staged calcination, and the rest of the operations are consistent with those of the calcination stage of Example 4.

[0054] (3) The post-treatment stage: only use a superfine pulverizer to crush the crude calcium oxide to a particle size of 100 nm, without ultrasonic treatment, and finally obtain the calcium oxide product.

[0055] Comparative Example 5:

[0056] (1) The raw material pretreatment stage: taking limestone with a purity of 98.5wt%, using a common pulverizer to crush it to a particle size of 50 μm, without adding an activator, and drying at 105°C for 2 hours.

[0057] (2) The calcination stage: using a double-chamber kiln to calcine in stages, the high-temperature zone temperature is 1000°C and the low-temperature zone temperature is 700°C, the CO2 concentration in the kiln is controlled to be 25vol%, and the temperature is kept for 3 hours under this condition.

[0058] (3) The post-treatment stage: only use a common pulverizer to crush the crude calcium oxide to a particle size of 420 nm, without ultrasonic treatment and acid pickling, and finally obtain the calcium oxide product.

[0059] Comparative Example 6:

[0060] (1) The raw material pretreatment stage: taking calcium carbonate with a purity of 99.0wt%, mixing with nanocellulose templates at a mass ratio of 10:1, adding deionized water to stir to form slurry, and drying at 60°C for 2 hours.

[0061] (2) The calcination stage: under a nitrogen atmosphere, the temperature is raised to 950°C at a rate of 10°C / min and kept for 3 hours, and the template is pyrolyzed through this process, and the rest of the operations are consistent with those of the conventional template method calcination.

[0062] (3) The post-treatment stage: without acid pickling operation, use a superfine pulverizer to crush the crude calcium oxide to a particle size of 280 nm, and finally obtain the calcium oxide product.

[0063] Performance test and result analysis:

[0064] Test method:

[0065] (1) Purity test adopts EDTA complexometric titration method, through which the mass fraction of calcium oxide is determined;

[0066] (2) Particle size test adopts laser particle size analyzer, through which the volume average particle size D50 of the product is determined;

[0067] (3) Specific surface area test adopts BET nitrogen adsorption method, through which the specific surface area of the product is determined;

[0068] (4) Activity test adopts hydration rate method, specifically, the time required for 10 g of calcium oxide to be completely hydrated in 50 mL of water at 25°C is determined;

[0069] (5) Impurity test adopts ICP-MS, through which the total mass fraction of three main impurities, i.e., silicon, iron and magnesium, in the product is determined.

[0070] The test results are shown in Table 1 below:

[0071] No. Product purity wt% Particle size D50 nm Specific surface area m 2 / g]] Hydration time min Total impurity content wt% Example 1 99.2 500 15.2 30 0.8 Example 2 99.5 300 22.5 20 0.5 Example 3 99.7 200 30.8 15 0.3 Example 4 99.9 100 40.1 10 0.1 Comparative Example 1 98.5 600 8.6 45 1.5 Comparative Example 2 98.8 350 12.3 35 1.2 Comparative Example 3 97.5 550 10.1 50 2.5 Comparative Example 4 99.6 120 28.7 18 0.4 Comparative Example 5 98.9 420 14.8 28 1.1 Comparative Example 6 98.7 280 25.3 22 0.9

[0072] From the above Table 1, the following results can be obtained:

[0073] (1) From the performance data of Examples 1 to 4, it can be clearly seen that with the progressive optimization of the process, the comprehensive performance of the product has achieved a step-by-step breakthrough. The purity of the raw material has been gradually improved from 98.5wt% to 99.9wt%, the particle size of the raw material has been refined from 10μm to 1μm, the activator has been gradually upgraded from no addition to citric acid-stearic acid composite activator, the calcination atmosphere has been optimized from air to argon and the introduction of a staged calcination process, and the post-treatment has been gradually upgraded from simple crushing to a combination process of ultrasonic treatment and acid pickling. These multi-linkage synergistic optimization measures have collectively contributed to the steady improvement of the product purity from 99.2wt% to 99.9wt%, fully meeting the stringent requirements of high-end fields for high purity; the particle size has been significantly reduced from 500nm to 100nm, effectively improving the dispersibility and reaction contact area of the product; the specific surface area has been greatly improved from 15.2m 2 / g to 40.1m 2 / g, providing a structural basis for the enhanced activity of the product; the hydration time has been shortened from 30 minutes to 10 minutes, directly reflecting the significant improvement in the reaction activity of the product; and the total impurity content has been reduced from 0.8wt% to 0.1wt%, effectively reducing the adverse effects of impurities on the application effect of the product.

[0074] (2) Comparing the performance data of each comparative example, it can be seen that Comparative Example 1 adopts a traditional rough machining process without raw material ultrafine pretreatment, activator addition and ultrasonic post-treatment, resulting in a product purity of only 98.5wt%, a particle size of up to 600nm and a specific surface area of only 8.6m 2wt%, and each performance index is far lower than that of the embodiment 1 of the present application, which fully embodies the necessity of optimization of the basic process of the present application. The comparative example 2 has a calcination temperature of only 700 DEG C, which is lower than the temperature required for complete decomposition of calcium carbonate, resulting in incomplete decomposition of calcium carbonate, a product purity of 98.8 wt%, and a specific surface area of 12.3 m 2 / g, which are lower than those of the embodiment 2, proving that the appropriate calcination temperature is the key to guaranteeing the performance of the product. The comparative example 3 uses low-quality raw material with a purity of only 97.0 wt% and does not perform acid washing to remove impurities, and the product has a purity of only 97.5 wt% and a total impurity content of 2.5 wt%, highlighting the importance of selection of high-purity raw material and the fine impurity removal process to the control of product purity. The comparative example 4 omits the steps of staged calcination and ultrasonic treatment, although the raw material and activator are configured in accordance with the embodiment 4, the product has a particle size of 120 nm and a specific surface area of 28.7 m 2 / g, which are lower than those of the embodiment 4, proving the important role of staged calcination in promoting impurity removal and grain refinement and the important role of ultrasonic treatment in breaking the particle agglomeration.

[0075] (3) The comparative example 5 adopts the existing double-kiln calcination process, and the product has a purity of 98.9 wt%, a particle size of 420 nm, and a total impurity content of 1.1 wt%, which is 0.8 wt% lower in purity, 220 nm larger in particle size, and 0.8 wt% higher in impurity content than the embodiment 3 of the present application, which embodies the significant advantages of the process of the present application in purity improvement, particle size refinement, and impurity control. The comparative example 6 adopts the existing template method process, and because the template pyrolysis residue is carbonaceous impurities and does not perform acid washing to remove impurities, the product has a purity of 98.7 wt% and a total impurity content of 0.9 wt%, which is lower than 99.5 wt% and 0.5 wt% of the embodiment 2 of the present application, and the pore structure stability is insufficient, proving that the technical solution of the present application using a composite activator to replace the template is more practical and superior.

[0076] In summary, the present application realizes the simultaneous breakthrough of key performance indicators such as calcium oxide purity, particle size, specific surface area, activity, and impurity content through systematic and synergistic optimization of raw material pretreatment, calcination process, and post-treatment links. The progressive design of each embodiment clearly shows the direct correlation between process optimization and performance improvement, and the comparison with the traditional process and the existing improved process further confirms the significant progress of the technical solution of the present application. The prepared ultra-fine high-purity calcium oxide can meet the application requirements of high-end fields.

[0077] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details and do not limit the application to the specific embodiments described. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application principles and their practical application, so that those skilled in the art can well understand and utilize the application.

Claims

1. An ultrafine high purity calcium oxide, characterized by, The purity of the calcium oxide is ≥99.2wt%, the particle size D50 is ≤500nm, the total content of impurities is ≤0.8wt%, and the specific surface area is ≥15.2m 2 / g; the impurities are a mixture of silicon, iron and magnesium.

2. The ultrafine high purity calcium oxide according to claim 1, characterized in that, The purity of the calcium oxide is ≥ 99.5 wt%, the particle size D50 is ≤ 300 nm, the total content of impurities is ≤ 0.5 wt%, and the specific surface area is ≥ 22.5 m 2 / g.

3. The ultrafine high-purity calcium oxide according to claim 2, characterized in that, The purity of the calcium oxide is ≥ 99.7 wt%, the particle size D50 is ≤ 200 nm, the total content of impurities is ≤ 0.3 wt%, and the specific surface area is ≥ 30.8 m 2 / g.

4. The ultrafine high purity calcium oxide according to claim 3, characterized in that, The purity of the calcium oxide is ≥ 99.9wt%, the particle size D50 is ≤ 100 nm, the total impurity content is ≤ 0.1wt%, and the specific surface area is ≥ 40.1 m 2 / g.

5. The ultrafine high purity calcium oxide according to any one of claims 1 to 4, characterized in that, The hydration time of the calcium oxide is ≤ 30 min.

6. A process for preparing ultrafine high-purity calcium oxide as described in any one of claims 1-5, characterized in that, The method comprises the following steps: (1) raw material pretreatment: taking calcium carbonate raw material, crushing it and adding deionized water to stir to form a slurry, filtering after stirring, drying the obtained solid to obtain pretreated calcium carbonate; (2) calcination: placing the pretreated calcium carbonate in a muffle furnace, heating to a preset temperature at a preset heating rate under a preset atmosphere, and then cooling to room temperature to obtain crude calcium oxide; (3) post-treatment: crushing the crude calcium oxide to obtain superfine high-purity calcium oxide product.

7. The manufacturing process of claim 6, wherein, In step (1), the calcium carbonate raw material is at least one of calcite, marble or light calcium carbonate, and the purity of the calcium carbonate raw material is ≥ 98.5wt%; the particle size of the crushed raw material is ≤ 10μm; the solid-liquid ratio when adding deionized water is 1:2-1:5; an activator is also added during stirring, the activator is at least one of citric acid, stearic acid or citric acid-stearic acid composite activator, and the addition amount of the activator is 0.3wt%-0.8wt% of the mass of the calcium carbonate raw material; the stirring temperature is 30℃-50℃, and the stirring time is 30min-75min; the drying temperature is 105℃-120℃, and the drying time is 0.5h-2h.

8. The manufacturing process of claim 6, wherein, In step (2), the preset atmosphere is one of air, nitrogen or argon; when the preset atmosphere is nitrogen, the nitrogen flow rate is 2L / min; when the preset atmosphere is argon, the argon flow rate is 3L / min; the preset heating rate is 8℃ / min-12℃ / min; the preset temperature is 850℃-1000℃, and the holding time is 2h-3h.

9. The manufacturing process of claim 8, wherein, In step (2), a staged calcination method is used: first, heating to 600℃ at a heating rate of 8℃ / min and holding for 1h, and then heating to 1000℃ at a heating rate of 10℃ / min and holding for 2h.

10. The manufacturing process of claim 6, wherein, In step (3), the crude calcium oxide is first subjected to ultrasonic treatment before crushing, the ultrasonic treatment power is 500W-800W, and the treatment time is 30min-50min; after ultrasonic treatment, dilute hydrochloric acid is also added for stirring, the mass fraction of the dilute hydrochloric acid is 5%, the addition amount of the dilute hydrochloric acid is 0.5wt% of the mass of the crude calcium oxide, and the stirring time is 15min; after stirring, filtering, washing the obtained solid with deionized water to neutral, drying at 110℃ for 1h, and finally crushing.