Grinding Aids, Their Preparation Methods, and Pre-Processing Techniques for Nanoscale Crushing of Nano Hydrocarbon Fuels

Abstract

The present invention provides a grinding aid, a preparation method thereof, and a pre-treatment process for nano-crushing of nano-hydrocarbon fuel. The grinding aid provided by the present invention, by mass percentage, comprises 30% - 65% of sodium pyrophosphate, 25% - 40% of aluminum chloride, and 10% - 30% of calcium carbonate. By applying the technical solution of the present invention, the grinding aid provided by the present invention synergistically combines sodium pyrophosphate, aluminum chloride, and calcium carbonate in a specific mass ratio. On the one hand, it adsorbs on the surface of coal powder particles, causing dislocation migration of the near-surface lattice, generating point or line defects, slowing down the crystal growth rate, reducing the generation of agglomeration, and lowering the strength and hardness of coal powder particles. On the other hand, it penetrates into the cracks generated by the crushing of coal powder particles, increases the repulsive force between particles, prevents the closure of newly generated cracks, promotes the expansion of cracks, improves the product fineness, thereby enhancing the ultra-fine grinding efficiency of coal powder, reducing the energy consumption per unit product, and further improving the production efficiency of nano-hydrocarbon fuel.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding aids, and in particular, to a grinding aid and a pre - process for nano - pulverizing nano - hydrocarbon fuel. Background Art

[0002] Nano - hydrocarbon fuel is a new type of ultra - fine particle fuel developed by using industrial nano - powder production technology and other supporting processes to process coal. It has a high specific surface area and surface activity, and has the characteristics of high combustion efficiency and low pollutant emissions. It is an efficient and clean new type of coal - based special fuel.

[0003] During the preparation of nano - hydrocarbon fuel, when pulverized coal is ultra - finely pulverized to the micron level, the specific surface area and surface energy of the pulverized coal particles increase sharply, the agglomeration phenomenon intensifies, and the pulverized coal particles gradually reach a dynamic equilibrium state of pulverization - agglomeration. With the extension of the ultra - fine pulverization time, the crystal structure of the pulverized coal particles changes, the adsorption ability between the pulverized coal particles increases, the agglomeration phenomenon further intensifies, the particle size of the pulverized coal particles no longer decreases, and even shows a tendency of "becoming coarser", resulting in a significant decrease in pulverization efficiency and a significant increase in energy consumption per unit product.

[0004] Adding a suitable grinding aid is one of the methods to improve the pulverization efficiency of pulverized coal and reduce energy consumption. The ultra - fine pulverization process is not only a simple physical process of reducing particle size, but also involves changes in the physical and chemical properties of pulverized coal particles caused by mechanical ultra - fine pulverization. Existing technologies have studied the mechanochemical effect in the ultra - fine pulverization process more, but the influence of the physical and chemical property changes of pulverized coal particles during the ultra - fine pulverization process on the selection of grinding aids and processing efficiency is almost blank.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The main object of the present invention is to provide a grinding aid, its preparation method and a pre - process for nano - pulverizing nano - hydrocarbon fuel, so as to solve the technical problems that during the existing ultra - fine pulverization process, with the extension of time, the crystal structure of pulverized coal particles changes, the agglomeration phenomenon further intensifies, resulting in a significant decrease in pulverization efficiency and a significant increase in energy consumption per unit product.

[0007] To achieve the above object, according to one aspect of the present invention, a grinding aid is provided, which comprises 30% - 65% of sodium pyrophosphate, 25% - 40% of aluminum chloride, and 10% - 30% of calcium carbonate.

[0008] Further, in the above - mentioned grinding aid, the mass content of sodium pyrophosphate is 45% - 55%, the mass content of aluminum chloride is 25% - 35%, and the mass content of calcium carbonate is 15% - 25%.

[0009] Further, in the above grinding aid, the mass content of sodium pyrophosphate is 50%, the mass content of aluminum chloride is 30%, and the mass content of calcium carbonate is 20%.

[0010] Further, in the above grinding aid, sodium pyrophosphate, aluminum chloride, and calcium carbonate are all in powder form, and the particle size D50 of sodium pyrophosphate, aluminum chloride, and calcium carbonate is independently 0.5 - 50 μm, preferably 1 μm.

[0011] According to the second aspect of the present invention, a method for preparing the above grinding aid is also provided. The preparation method includes the following steps: mixing raw materials including sodium pyrophosphate, aluminum chloride, and calcium carbonate to obtain the grinding aid.

[0012] According to the third aspect of the present invention, a pre - process for nano - pulverizing nano - hydrocarbon fuel is also provided. The pre - process includes: mixing coal slurry and a grinding aid to obtain a modified raw material for preparing nano - hydrocarbon fuel, wherein the grinding aid is any one of the grinding aids provided in the first aspect above or the grinding aid obtained by the preparation method provided in the second aspect above.

[0013] Further, the above mixing method is stirring. Preferably, the stirring speed is 40 - 120 revolutions per minute, and the stirring duration is 25 - 45 minutes.

[0014] Further, the above coal slurry includes solid substances and water. The coal slurry includes coal powder particles and water. In the coal slurry, the mass content of coal powder particles is 20% - 40%, preferably 25%.

[0015] Further, the mass ratio of the grinding aid to the coal powder particles is 0.5 - 5:1000, preferably 0.85:1000.

[0016] Further, the particle size D50 of the coal powder particles is 10 - 100 μm.

[0017] Further, the coal powder particles are obtained by pulverizing raw coal. The raw coal includes the following components by mass percentage: carbon 63 - 65%, alumina 13% - 15%, silica 8% - 10%, calcium oxide 1.5% - 2.0%, and iron oxide 1.0% - 2.0%.

[0018] Applying the technical solution of the present invention, the grinding aid provided by the present invention synergistically combines sodium pyrophosphate, aluminum chloride, and calcium carbonate in specific mass ratios. On the one hand, it adsorbs on the surface of coal powder particles, causing dislocation migration of the near-surface lattice, generating point or line defects, slowing down the crystal growth rate, reducing the generation of agglomeration, and lowering the strength and hardness of coal powder particles. On the other hand, it penetrates into the cracks generated by the pulverization of coal powder particles, increases the repulsive force between particles, prevents the closure of newly generated cracks, promotes the expansion of cracks, improves the product fineness, thereby enhancing the ultrafine pulverization efficiency of coal powder, reducing the energy consumption per unit product, and further improving the production efficiency of nano hydrocarbon fuel. Specific Embodiments

[0019] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0020] As analyzed in the background art of this application, during the existing ultrafine pulverization process of coal powder, as time goes by, the crystal structure of coal powder particles changes, and the agglomeration phenomenon is further aggravated, resulting in the technical problems of a significant decline in pulverization efficiency and a significant increase in energy consumption per unit product. To solve this technical problem, this application provides a grinding aid, its preparation method, and a pre-nano pulverization process for nano hydrocarbon fuel.

[0021] In a typical embodiment of this application, a grinding aid is provided. By mass percentage, the grinding aid includes 30% - 65% of sodium pyrophosphate, 25% - 40% of aluminum chloride, and 15% - 30% of calcium carbonate.

[0022] The grinding aid provided by the present invention synergistically combines sodium pyrophosphate, aluminum chloride, and calcium carbonate in specific mass ratios. On the one hand, it adsorbs on the surface of coal powder particles, causing dislocation migration of the near-surface lattice, generating point or line defects, slowing down the crystal growth rate, reducing the generation of agglomeration, and lowering the strength and hardness of coal powder particles. On the other hand, it penetrates into the cracks generated by the pulverization of coal powder particles, increases the repulsive force between particles, prevents the closure of newly generated cracks, promotes the expansion of cracks, improves the product fineness, thereby enhancing the ultrafine pulverization efficiency of coal powder, reducing the energy consumption per unit product, and further improving the production efficiency of nano hydrocarbon fuel.

[0023] To further improve the grinding effect of the above-mentioned grinding aid, preferably in some embodiments of this application, in the above-mentioned grinding aid, the mass content of sodium pyrophosphate is 45% - 55%, the mass content of aluminum chloride is 25% - 35%, and the mass content of calcium carbonate is 15% - 25%. Especially when the mass content of sodium pyrophosphate in the grinding aid is 50%, the mass content of aluminum chloride is 30%, and the mass content of calcium carbonate is 20%, the grinding efficiency of the grinding aid is more remarkable.

[0024] In order to further improve the mixing efficiency of sodium pyrophosphate, aluminum chloride and calcium carbonate, it is preferred that sodium pyrophosphate, aluminum chloride and calcium carbonate are all in powder form, and their respective particle sizes D50 are all 0.5 - 50 μm. Especially when the particle sizes of sodium pyrophosphate, aluminum chloride and calcium carbonate are all 1 μm, it is more conducive to improving the mixing efficiency, and the mixing between the raw materials is more uniform.

[0025] Typically but not restrictively, in the grinding aid provided in the present application, the mass content of sodium pyrophosphate is, for example, 30%, 35%, 40%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65% or a range value between any two values; the mass content of aluminum chloride is, for example, 25%, 28%, 30%, 32%, 35%, 38%, 40% or a range value between any two values; the mass content of calcium carbonate is, for example, 15%, 18%, 20%, 22%, 25%, 28%, 30% or a range value between any two values; the particle sizes D50 of sodium pyrophosphate, aluminum chloride and calcium carbonate are each independently, for example, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm or a range value between any two values.

[0026] In another typical embodiment of the present application, a preparation method of a grinding aid is also provided. The preparation method includes the following steps: mixing raw materials including sodium pyrophosphate, aluminum chloride and calcium carbonate to obtain a grinding aid.

[0027] The preparation method of the grinding aid provided in the present application has a simple process and is easy to operate, is suitable for large-scale production, and effectively improves the preparation efficiency.

[0028] In a third typical embodiment of the present application, a pre-treatment process for nano-grinding of nano-hydrocarbon fuel is also provided. The pre-treatment process includes: mixing coal slurry and a grinding aid to obtain a modified raw material for preparing nano-hydrocarbon fuel, wherein the grinding aid is any one of the grinding aids provided in the first typical embodiment above or the grinding aid obtained according to the preparation method provided in the second typical embodiment above.

[0029] The above-mentioned coal slurry contains solid substances and water. The solid substances are mainly coal powder particles, and the solid substances may also include additives. In view of the very low content of additives in the solid substances and being negligible, the mass content of coal powder particles in the present application is the mass content of the solid substances in the coal slurry.

[0030] Applying the technical solution of the present application, after mixing the above grinding aid with the coal slurry and performing nano-crushing treatment, on the one hand, the grinding aid adsorbs on the surface of the coal powder particles, causing dislocation migration of the near-surface lattice, generating point or line defects, slowing down the crystal growth rate, reducing the generation of agglomeration, and lowering the strength and hardness of the coal powder particles. On the other hand, the grinding aid penetrates into the cracks generated by the crushing of the coal powder particles, increasing the repulsive force between the particles, preventing the closure of the newly generated cracks, promoting the expansion of the cracks, improving the product fineness, thereby improving the ultra-fine crushing efficiency of the coal powder, reducing the energy consumption per unit product, and further improving the production efficiency of the nano hydrocarbon fuel.

[0031] In order to further improve the efficiency of subsequent nano-crushing, it is preferred that the above pre-treatment process includes: mixing the coal slurry and the grinding aid by stirring to obtain a modified raw material for preparing nano hydrocarbon fuel.

[0032] By mixing the coal slurry and the grinding aid by stirring, it is more conducive to the uniform dispersion of the grinding aid in the coal slurry, so that when the modified raw material for preparing nano hydrocarbon fuel is subjected to subsequent nano-crushing treatment, the nano-crushing efficiency can be further improved.

[0033] In order to further improve the mixing efficiency, it is preferred that the stirring speed is 40 - 120 revolutions per minute and the stirring duration is 25 - 45 minutes.

[0034] Typically but not restrictively, when mechanically stirring and mixing the coal slurry and the grinding aid, the stirring speed can be 40 revolutions per minute, 50 revolutions per minute, 60 revolutions per minute, 70 revolutions per minute, 80 revolutions per minute, 90 revolutions per minute, 100 revolutions per minute, 110 revolutions per minute, 120 revolutions per minute or a range value composed of any two values; the stirring duration can be 25 minutes, 28 minutes, 30 minutes, 32 minutes, 35 minutes, 38 minutes, 40 minutes, 42 minutes, 45 minutes or a range value composed of any two values.

[0035] The above coal slurry is mainly obtained by dispersing coal powder particles in water. In order to further improve the efficiency of subsequent nano-crushing treatment, it is preferred that in the coal slurry, the mass content of the coal powder particles is 20% - 40%. Especially when the mass content of the coal powder particles in the coal slurry is 25%, it is more conducive to improving the efficiency of subsequent nano-crushing treatment.

[0036] In order to further improve the grinding effect of the grinding aid, it is preferred that the mass ratio of the grinding aid to the solid substance is 0.5 - 5:1000. Especially when the mass ratio of the grinding aid to the coal powder particles is 0.85:1000, its grinding efficiency is more remarkable.

[0037] In order to further shorten the time of subsequent nano-crushing treatment, it is preferred that the particle size of the coal powder particles is preferably 10 - 100 μm to further improve the efficiency of nano-crushing treatment.

[0038] Typical but non-limiting, in the above-mentioned coal slurry, the mass content of coal powder particles is, for example, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40% or a range value composed of any two numerical values; the mass ratio of the above grinding aid to coal powder particles is, for example, 0.5:1000, 0.8:1000, 1:1000, 1.2:1000, 1.5:1000, 1.8:1000, 2:1000, 2.5:1000, 3:1000, 3.5:1000, 4:1000, 4.5:1000, 5:1000 or a range composed of any two numbers; in the above-mentioned coal slurry, the particle size of coal powder particles is, for example, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 100nm or a range value composed of any two numerical values.

[0039] The above coal powder particles are obtained by pulverizing raw coal. In order to further improve the grinding efficiency, it is preferred that the raw coal includes the following components by mass percentage: carbon 63% - 65%, alumina 13% - 15%, silica 8% - 10%, calcium oxide 1.5% - 2.0%, iron oxide 1.0% - 2.0%.

[0040] Typical but non-limiting, in the above-mentioned raw coal, the mass content of carbon is, for example, 63%, 63.5%, 64%, 64.5%, 65% or a range composed of any two numerical values; the content of alumina is, for example, 13%, 13.5%, 14%, 14.5%, 15% or a range composed of any two numerical values; the mass content of silica is, for example, 8%, 8.5%, 9%, 9.5%, 10% or a range composed of any two numerical values; the mass content of calcium oxide is, for example, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0% or a range composed of any two numerical values; the mass content of iron oxide is, for example, 1.0%, 1.2%, 1.5%, 1.8%, 2.0% or a range value composed of any two numerical values.

[0041] Next, the beneficial effects of the present application will be further described in conjunction with examples and comparative examples.

[0042] Example 1

[0043] This example provides a grinding aid. By mass percentage, the grinding aid includes 50% sodium pyrophosphate, 30% aluminum chloride, and 20% calcium carbonate.

[0044] Example 2

[0045] The difference between this example and Example 1 is that in the grinding aid, the mass content of sodium pyrophosphate is 55%, the mass content of aluminum chloride is 30%, and the mass content of calcium carbonate is 15%.

[0046] Example 3

[0047] The difference between this example and Example 1 lies in that in the grinding aid, the mass content of sodium pyrophosphate is 45%, the mass content of aluminum chloride is 30%, and the mass content of calcium carbonate is 25%.

[0048] Example 4

[0049] The difference between this example and Example 1 lies in that in the grinding aid, the mass content of sodium pyrophosphate is 30%, the mass content of aluminum chloride is 40%, and the mass content of calcium carbonate is 30%.

[0050] Example 5

[0051] The difference between this example and Example 1 lies in that in the grinding aid, the mass content of sodium pyrophosphate is 65%, the mass content of aluminum chloride is 25%, and the mass content of calcium carbonate is 10%.

[0052] Comparative Example 1

[0053] The difference between this comparative example and Example 1 lies in that the grinding aid does not contain calcium carbonate, the mass content of sodium pyrophosphate is 60%, and the content of aluminum chloride is 40%.

[0054] Comparative Example 2

[0055] The difference between this comparative example and Example 1 lies in that the grinding aid does not contain sodium pyrophosphate, the mass content of aluminum chloride is 60%, and the mass content of calcium carbonate is 40%.

[0056] Comparative Example 3

[0057] The difference between this comparative example and Example 1 lies in that the grinding aid does not contain aluminum chloride, the mass content of sodium pyrophosphate is 70%, and the mass content of calcium carbonate is 30%.

[0058] Comparative Example 4

[0059] The difference between this comparative example and Example 1 lies in that in the grinding aid, the mass content of sodium pyrophosphate is 25%, the mass content of aluminum chloride is 60%, and the mass content of calcium carbonate is 15%.

[0060] Comparative Example 5

[0061] The difference between this comparative example and Example 1 lies in that in the grinding aid, the mass content of sodium pyrophosphate is 80%, the mass content of aluminum chloride is 15%, and the mass content of calcium carbonate is 5%.

[0062] The grinding aids provided in the above examples and comparative examples are all prepared by mixing various raw materials.

[0063] Example 6

[0064] This embodiment provides a pre - process for nano - pulverizing nano - hydrocarbon fuel, including the following steps:

[0065] Mix the coal slurry and the grinding aid provided in Example 1 under mechanical stirring. The stirring speed is 60 revolutions per minute, and the stirring duration is 30 minutes to obtain a modified raw material for preparing nano - hydrocarbon fuel. Among them, the mass content of coal powder particles in the coal slurry is 25%, the mass ratio of the grinding aid to the coal powder particles is 0.85‰, the particle size of the coal powder particles is 10 - 100 nm, which is obtained by pulverizing raw coal. The raw coal includes the following components by mass percentage: carbon 63% - 65%, alumina 13% - 15%, silica 8% - 10%, calcium oxide 1.5% - 2.0%, iron oxide 1.0% - 2.0%.

[0066] Examples 7 - 10

[0067] Examples 7 - 10 respectively provide a pre - process for nano - pulverizing nano - hydrocarbon fuel. The differences from Example 6 are that the grinding aids provided in Examples 2 - 5 are respectively used to replace the grinding aid provided in Example 1.

[0068] Example 11

[0069] The difference between this example and Example 6 is that in step (2), the addition amount of the grinding aid is 0.5‰ of the mass of the coal powder particles.

[0070] Example 12

[0071] The difference between this example and Example 6 is that in step (2), the addition amount of the grinding aid is 5‰ of the mass of the coal powder particles.

[0072] Example 13

[0073] The difference between this example and Example 6 is that in step (2), the addition amount of the grinding aid is 8‰ of the mass of the coal powder particles.

[0074] Example 14

[0075] The difference between this example and Example 6 is that in step (2), the addition amount of the grinding aid is 0.2‰ of the mass of the coal powder particles.

[0076] Comparative Examples 6 - 10

[0077] The differences between Comparative Examples 6 - 10 and Example 6 are that the grinding aids provided in Comparative Examples 1 - 5 are respectively used to replace the grinding aid provided in Example 1.

[0078] Comparative Example 11

[0079] The difference between this comparative example and Example 6 is that no grinding aid is added to the coal slurry.

[0080] Test Example 1

[0081] The modified raw materials for preparing the nano-hydrocarbon fuel in the above Examples 6-14 and Comparative Examples 6-11 were respectively put into a nano-crusher for nano-crushing, and the particle sizes of the pulverized coal particles obtained by crushing were detected at different time points. The results are shown in Table 1 below, where the sampling time refers to the timing time starting from when the nano-crusher was started for nano-crushing.

[0082] Table 1

[0083]

[0084]

[0085]

[0086] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0087] By applying the technical solution of the present invention, the grinding aid provided by the present invention synergistically combines sodium pyrophosphate, aluminum chloride and calcium carbonate with a specific mass ratio. On the one hand, it adsorbs on the surface of the pulverized coal particles, causing dislocation migration of the near-surface lattice, generating point or line defects, slowing down the crystal growth rate, reducing the generation of agglomeration, and reducing the strength and hardness of the pulverized coal particles. On the other hand, it penetrates into the cracks generated by the crushing of the pulverized coal particles, increases the repulsive force between the particles, prevents the closure of the newly generated cracks, promotes the expansion of the cracks, improves the product fineness, thereby improving the ultra-fine pulverization efficiency of the pulverized coal, reducing the unit product energy consumption, and further improving the production efficiency of the nano-hydrocarbon fuel.

[0088] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An abrasive aid for the pre - process of nano - pulverizing nano - hydrocarbon fuel, characterized in that, By mass percentage, the grinding aid comprises 30% - 65% of sodium pyrophosphate, 25% - 40% of aluminum chloride, and 10% - 30% of calcium carbonate; The sodium pyrophosphate, the aluminum chloride, and the calcium carbonate are all in powder form, and the particle size D50 of the sodium pyrophosphate, the aluminum chloride, and the calcium carbonate is independently 0.5 - 50 μm.

2. The abrasive aid for the pre - process of nano - pulverizing nano - hydrocarbon fuel according to claim 1, characterized in that, In the grinding aid, the mass content of the sodium pyrophosphate is 45% - 55%, the mass content of the aluminum chloride is 25% - 35%, and the mass content of the calcium carbonate is 15% - 25%.

3. The abrasive aid for the pre - process of nano - pulverizing nano - hydrocarbon fuel according to claim 1, characterized in that, In the grinding aid, the mass content of the sodium pyrophosphate is 50%, the mass content of the aluminum chloride is 30%, and the mass content of the calcium carbonate is 20%; And / or, the sodium pyrophosphate, the aluminum chloride, and the calcium carbonate are all in powder form, and the particle size D50 of the sodium pyrophosphate, the aluminum chloride, and the calcium carbonate is independently 1 μm.

4. The preparation method of the abrasive aid for the pre - process of nano - pulverizing nano - hydrocarbon fuel according to any one of claims 1 to 3, characterized in that, The preparation method comprises the following steps: mixing raw materials including the sodium pyrophosphate, the aluminum chloride, and the calcium carbonate to obtain the grinding aid.

5. A pre - process of nano - pulverizing nano - hydrocarbon fuel, characterized in that, The pre - process includes: mixing coal slurry and the grinding aid to obtain modified raw materials for preparing nano - hydrocarbon fuel, wherein the grinding aid is the grinding aid according to any one of claims 1 to 3 or the grinding aid obtained by the preparation method according to claim 4.

6. The pre - process according to claim 5, characterized in that, The mixing method is stirring.

7. The pre - process according to claim 6, characterized in that, The stirring speed is 40 - 120 revolutions per minute, and the stirring duration is 25 - 45 minutes.

8. The pre - process according to claim 5, characterized in that, The coal slurry comprises coal powder particles and water. In the coal slurry, the mass content of the coal powder particles is 20% - 40%.

9. The pre - process according to claim 8, characterized in that, The mass content of the coal powder particles is 25%.

10. The pre - process according to claim 8 or 9, characterized in that, The mass ratio of the grinding aid to the coal powder particles is 0.5 - 5:1000.

11. The pre - process according to claim 8 or 9, characterized in that, The mass ratio of the grinding aid to the coal powder particles is 0.85:1000.

12. The pre - process according to claim 8 or 9, characterized in that, The particle size D50 of the coal powder particles is 10 - 100 μm.

13. The pre - process according to claim 8 or 9, characterized in that, The coal powder particles are obtained by pulverizing raw coal, and the raw coal comprises the following components by mass percentage: 63% - 65% of carbon, 13% - 15% of alumina, 8% - 10% of silica, 1.5% - 2.0% of calcium oxide, and 1.0% - 2.0% of iron oxide.

Images