CN111591993A - Method for producing blocky calcium oxide by using carbide slag - Google Patents
Method for producing blocky calcium oxide by using carbide slag Download PDFInfo
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- CN111591993A CN111591993A CN202010472980.0A CN202010472980A CN111591993A CN 111591993 A CN111591993 A CN 111591993A CN 202010472980 A CN202010472980 A CN 202010472980A CN 111591993 A CN111591993 A CN 111591993A
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- carbide slag
- calcium oxide
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- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 239000002893 slag Substances 0.000 title claims abstract description 64
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 title claims abstract description 62
- 239000000292 calcium oxide Substances 0.000 title claims abstract description 61
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 38
- 239000011230 binding agent Substances 0.000 claims abstract description 33
- 239000000203 mixture Substances 0.000 claims abstract description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910001868 water Inorganic materials 0.000 claims abstract description 31
- 238000001354 calcination Methods 0.000 claims abstract description 26
- 238000001035 drying Methods 0.000 claims abstract description 23
- 239000007864 aqueous solution Substances 0.000 claims abstract description 21
- 239000000853 adhesive Substances 0.000 claims abstract description 16
- 230000001070 adhesive effect Effects 0.000 claims abstract description 16
- 229910000403 monosodium phosphate Inorganic materials 0.000 claims abstract description 15
- 235000019799 monosodium phosphate Nutrition 0.000 claims abstract description 15
- AJPJDKMHJJGVTQ-UHFFFAOYSA-M sodium dihydrogen phosphate Chemical compound [Na+].OP(O)([O-])=O AJPJDKMHJJGVTQ-UHFFFAOYSA-M 0.000 claims abstract description 15
- BNIILDVGGAEEIG-UHFFFAOYSA-L disodium hydrogen phosphate Chemical compound [Na+].[Na+].OP([O-])([O-])=O BNIILDVGGAEEIG-UHFFFAOYSA-L 0.000 claims abstract description 12
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 238000003825 pressing Methods 0.000 claims abstract description 10
- 239000003054 catalyst Substances 0.000 claims abstract description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 14
- 238000000465 moulding Methods 0.000 claims description 14
- 239000004115 Sodium Silicate Substances 0.000 claims description 9
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 9
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 9
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 239000000243 solution Substances 0.000 claims 1
- 239000003245 coal Substances 0.000 abstract description 9
- 238000000034 method Methods 0.000 abstract description 8
- 239000002994 raw material Substances 0.000 abstract description 8
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 abstract description 7
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 abstract description 6
- 230000007613 environmental effect Effects 0.000 abstract description 3
- 238000012824 chemical production Methods 0.000 abstract description 2
- 238000004064 recycling Methods 0.000 abstract description 2
- 235000012255 calcium oxide Nutrition 0.000 description 45
- 238000012360 testing method Methods 0.000 description 28
- 239000008188 pellet Substances 0.000 description 12
- 239000005997 Calcium carbide Substances 0.000 description 10
- CLZWAWBPWVRRGI-UHFFFAOYSA-N tert-butyl 2-[2-[2-[2-[bis[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]amino]-5-bromophenoxy]ethoxy]-4-methyl-n-[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]anilino]acetate Chemical compound CC1=CC=C(N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)C(OCCOC=2C(=CC=C(Br)C=2)N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)=C1 CLZWAWBPWVRRGI-UHFFFAOYSA-N 0.000 description 9
- 238000011068 loading method Methods 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 239000002694 phosphate binding agent Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 239000004800 polyvinyl chloride Substances 0.000 description 4
- 239000000571 coke Substances 0.000 description 3
- 239000008187 granular material Substances 0.000 description 3
- 229920000915 polyvinyl chloride Polymers 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 239000002910 solid waste Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 210000003739 neck Anatomy 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000009740 moulding (composite fabrication) Methods 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/942—Calcium carbide
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/03—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
- C04B35/057—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on calcium oxide
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/6303—Inorganic additives
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
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Abstract
The invention belongs to the field of chemical production, and discloses a method for producing blocky calcium oxide by using carbide slag, which comprises the following steps: step 1, adding water into an adhesive to obtain an adhesive aqueous solution; step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; step 3, pressing and forming the mixture, drying at room temperature, drying, and calcining to obtain the catalyst; the method has the advantages that the carbide slag generated in the process of producing acetylene by using carbide is used as a main raw material, the recycling of the carbide slag is realized, the energy and environmental problems of the coal-based carbide industry are solved, and the maximum load capacity of calcium oxide obtained by matching with a binder of disodium hydrogen phosphate and sodium dihydrogen phosphate is over 85.8N.
Description
Technical Field
The invention relates to the field of chemical production, in particular to a method for producing blocky calcium oxide by using carbide slag.
Background
China has abundant coal resources, and has formed an industry cluster taking the modern coal chemical industry such as methanol from coal, olefin and dimethyl ether from methanol, fuel oil from coal and the like as a leading part in the field of basic chemical industry. The calcium carbide acetylene preparation process, one of the branches of coal chemical industry, has become an important link in the industrial production of polyvinyl chloride (PVC). The northwest industrial area of China develops a production mode taking coal, calcium carbide, acetylene and PVC as cores by depending on local resource and energy advantages, the production mode accounts for 80% of the total PVC production industry, and 1.5-1.9 t of calcium carbide slag is generated along with the production of lt PVC.
Although the carbide slag belongs to general industrial solid waste, the generation amount of the carbide slag is huge, so far, the stacking amount of the carbide slag in China exceeds thousands of tons, and the long-term stacking of the carbide slag can lead to the enrichment of a large amount of trace elements and further cause serious pollution to soil, water and the surrounding environment. Because the added value of the carbide slag is low, the utilization efficiency is poor, and the development of enterprises is seriously restricted if the treatment is not proper in the face of the huge stockpiling quantity. Therefore, the recycling of the carbide slag is realized, and the waste is changed into valuable.
Because the industrial production of calcium carbide adopts a moving bed production process, raw materials of semi-coke and calcium oxide (CaO) both need to have certain compressive strength to ensure that CO generated in the production process of the calcium carbide is smoothly discharged, and the obtaining of the blocky CaO with certain compressive strength from the calcium carbide slag is particularly important.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a method for producing blocky calcium oxide by using carbide slag, wherein the carbide slag generated in the acetylene production process by using carbide is used as a main raw material, the cyclic utilization of the carbide slag is realized, the energy and environmental problems in the coal-based calcium carbide industry are solved, and the maximum load capacity of calcium oxide obtained by matching disodium hydrogen phosphate and sodium dihydrogen phosphate binder is up to more than 85.8N.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme.
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into an adhesive to obtain an adhesive aqueous solution;
step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture;
and 3, pressing and forming the mixture, drying at room temperature, drying, and calcining to obtain the catalyst.
Preferably, the dosage proportion of the carbide slag, the binder and the water is as follows: (85-100): (9-15): 60.
preferably, the method further comprises adding the blue carbon into the carbide slag before adding the aqueous solution of the binder into the carbide slag.
Preferably, in step 1, the binder is inorganic sodium silicate, a mixture of phosphoric acid and silicate, sodium dihydrogen phosphate, and disodium hydrogen phosphate.
More preferably, in step 1, the binder is sodium dihydrogen phosphate or disodium hydrogen phosphate.
Further preferably, in step 1, the silicate is sodium silicate.
Preferably, in step 3, the number of times of the press forming is 2 to 10.
Preferably, in step 3, the drying time at room temperature is 12-24 hours.
Preferably, in step 3, the drying temperature is 100-.
Preferably, in step 3, the calcination temperature is 800-1100 ℃, the calcination time is 40-80min, and the temperature rise rate of the calcination is 10-22 ℃/min.
Further preferably, in step 3, the calcination temperature is 900 ℃, the calcination time is 60min, and the temperature rise rate of the calcination is 16 ℃/min.
Compared with the prior art, the invention has the beneficial effects that:
1) according to the method for producing the blocky calcium oxide by using the carbide slag, the carbide slag generated in the acetylene production process of the calcium carbide is used as a main raw material, a binder, water and other raw materials are added, and the blocky calcium oxide for the calcium carbide production is obtained through the processes of mixing, press forming, drying, calcining and the like, so that the cyclic utilization of solid waste in the acetylene production process is realized, and the energy and environmental problems in the coal-based calcium carbide industry are solved.
2) The carbide slag is used as a main raw material, so that the comprehensive utilization of industrial solid waste is realized, the production cost of carbide production enterprises is reduced, and the requirement of green and environment-friendly carbide production process is met.
3) Disodium hydrogen phosphate is used as a binder for converting carbide slag into calcium oxide, and the maximum load capacity of the obtained blocky calcium oxide reaches 88.9N; sodium dihydrogen phosphate is used as a binder for converting carbide slag into calcium oxide, and the maximum load capacity of the obtained massive calcium oxide reaches 85.8N.
Drawings
The invention is described in further detail below with reference to the figures and specific embodiments.
FIG. 1 is a schematic view showing the structure of the bulk calcium oxide obtained in example 1.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.
Example 1
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, mixing carbide slag and semi-coke to obtain solid powder.
And 2, adding water into the inorganic sodium silicate adhesive to obtain an adhesive aqueous solution.
Step 3, adding a binder aqueous solution into the solid powder, and uniformly mixing to obtain a mixture; wherein, carbide slag: semi-coke: inorganic sodium silicate binder: the water ratio is 80: 5: 15: 60.
and 4, pressing and molding the mixture by adopting a mold under proper pressure, standing at room temperature for 12 hours for maintenance and drying, drying and dehydrating at 105 ℃ for 2 hours, putting in a high-temperature furnace, heating to 950 ℃ at a speed of 16 ℃/min, carrying out heat preservation and calcination for 60 minutes, naturally cooling to about 50 ℃, transferring in a dryer, and preventing the water absorption from being decomposed to obtain the blocky calcium oxide, wherein the step is shown in figure 1.
Using an electronic universal tester with the model number of UTM5105And (3) testing the strength of the blocky calcium oxide, wherein the loading speed of an electronic universal tester is 0.5mm/min, and the maximum load of the obtained blocky calcium oxide is 8.85N. (conversion of Strength: maximum load N/contact area m2Pa, the stress surface is about 9-16 mm according to the shape of the sample2Namely 9 × 10-6～16×10-6m2The heat strength of the natural limestone is 11.9 MPa).
Example 2
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into phosphoric acid and sodium silicate to obtain a binder aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: the proportion of phosphoric acid, sodium silicate and water is 85: 10: 15: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure, standing at room temperature for 12 hours for maintenance and drying, drying and dehydrating at 105 ℃ for 2 hours, putting in a high-temperature furnace, heating to 950 ℃ at a speed of 16 ℃/min, carrying out heat preservation and calcination for 60 minutes, naturally cooling to about 50 ℃, transferring in a dryer, and preventing the water absorption from being decomposed to obtain the blocky calcium oxide.
The strength of the obtained blocky calcium oxide is tested by an electronic universal tester with the model number of UTM5105, the loading speed of the electronic universal tester is 0.5mm/min, and the maximum load of the obtained blocky calcium oxide is 29.74N.
Example 3
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into phosphoric acid and sodium silicate to obtain a binder aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: the proportion of phosphoric acid, sodium silicate and water is 85: 10: 15: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure (wherein the mixture sample is 2 parts and is respectively a mixture sample No. 1 and a mixture sample No. 2; the mixture sample No. 1 is knocked by an iron hammer for 2 times, and the mixture sample No. 2 is knocked by an iron hammer for 4 times), standing at room temperature, maintaining and drying for 12 hours, drying and dehydrating for 2 hours at 105 ℃, putting in a high-temperature furnace, heating to 950 ℃ at the speed of 16 ℃/min, performing heat preservation and calcination for 60 minutes, naturally cooling to about 50 ℃, transferring in a dryer, and preventing water absorption and decomposition to obtain the blocky calcium oxide No. 1 and the blocky calcium oxide No. 2.
The strength of the obtained 2 blocky calcium oxides is tested by an electronic universal tester with the model number of UTM5105, the loading speed of the electronic universal tester is 0.5mm/min, the maximum load of the obtained No. 1 blocky calcium oxide is 5.34N, and the maximum load of the No. 2 blocky calcium oxide is 25.85N.
The maximum load of the No. 1 blocky calcium oxide is obviously lower than that of the No. 2 blocky calcium oxide, which shows that the molding pressure has obvious influence on the strength of the product; the phosphoric acid as a binder can effectively improve the forming strength of the sample.
Example 4
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into a sodium dihydrogen phosphate adhesive to obtain an adhesive aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: sodium dihydrogen phosphate binder: the proportion of water is 85: 9: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure (the mixture is divided into 4 samples, wherein the No. 1 sample is knocked for 4 times, the No. 2 sample is knocked for 6 times, the No. 3 sample is knocked for 8 times, and the No. 4 sample is knocked for 10 times), standing at room temperature, maintaining, drying and dehydrating for 12 hours at 105 ℃, placing in a high-temperature furnace, heating to 950 ℃ at the speed of 16 ℃/min, preserving, calcining for 60 minutes, naturally cooling to about 50 ℃, transferring in a drier, preventing the decomposition of absorbed water, and obtaining 4 blocky calcium oxide which are respectively a test piece 1, a test piece 2, a test piece 3 and a test piece 4.
The strength of the obtained 4 blocks of calcium oxide was tested by an electronic universal tester of UTM5105 type, the loading speed of which was 0.5mm/min, the maximum load of test piece 1 was 23.3N, the maximum load of test piece 2 was 42.48N, the maximum load of test piece 3 was 65.41N, and the maximum load of test piece 4 was 85.8N.
From the above test results, it can be seen that, under a proper forming pressure, the sodium dihydrogen phosphate inorganic binder is used as a binder for preparing calcium oxide by pyrolyzing carbide slag, and the obtained calcium oxide product can basically meet the requirements of acetylene production on the form and strength of calcium oxide. The reason is that after the binder sodium dihydrogen phosphate is added, Ca (OH) and the sodium dihydrogen phosphate react to generate Ca-PH composite salt which possibly inhibits the abnormal growth of CaO particles in the sintering process, so that the size distribution range of sintering necks is narrowed, the number of the sintering necks in the pellets is increased, and the densification of the CaO pellets is possibly promoted actively, so that the process for strengthening the thermal strength of the CaO pellets by selecting the binder sodium dihydrogen phosphate has certain feasibility.
Example 5
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into a disodium hydrogen phosphate adhesive to obtain an adhesive aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: disodium hydrogen phosphate binder: the proportion of water is 100: 10: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure (the mixture is divided into 3 samples, wherein the No. 1 sample is knocked for 4 times, the No. 2 sample is knocked for 6 times, and the No. 3 sample is knocked for 8 times), standing at room temperature, maintaining, drying and dehydrating for 12 hours at 105 ℃, placing in a high-temperature furnace, heating to 950 ℃ at the speed of 16 ℃/min, maintaining, calcining for 60 minutes, naturally cooling to about 50 ℃, transferring into a drier, and preventing water absorption and decomposition to obtain 3 blocky calcium oxides which are respectively a test piece 1, a test piece 2 and a test piece 3.
The strength of the obtained 3 blocks of calcium oxide is tested by an electronic universal tester with the model number of UTM5105, the loading speed of the electronic universal tester is 0.5mm/min, the maximum load of a test piece 1 is 29.49N, the maximum load of a test piece 2 is 26.95N, the maximum load of a test piece 3 is 88.9N,
from the above data, it is found that, at an appropriate molding pressure, disodium hydrogen phosphate acts as a binder and enhances the thermal strength of CaO pellets.
Comparative example 1
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into a sodium dihydrogen phosphate adhesive to obtain an adhesive aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: sodium dihydrogen phosphate binder: the proportion of water is 85: 9: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure (the mixture is divided into 3 samples, wherein the No. 1 sample is knocked for 4 times, the No. 2 sample is knocked for 6 times, the No. 3 sample is knocked for 8 times, the mixture is placed at room temperature, maintained and dried for 12 hours, dried and dehydrated for 2 hours at 105 ℃, naturally cooled to about 50 ℃, and transferred into a drier to prevent water absorption decomposition, so that 3 blocky calcium oxides are obtained, namely the test piece 1, the test piece 2 and the test piece 3.
The strength of the obtained 3 blocks of calcium oxide was tested by an electronic universal tester of UTM5105, the loading speed of which was 0.5mm/min, the maximum load of test piece 1 was 20.512N, the maximum load of test piece 2 was 21.72N, and the maximum load of test piece 3 was 28.4N.
As can be seen from the data of example 4 and comparative example 1, the strength difference of the samples before calcination is small under different molding conditions, and the strength difference is obviously increased after calcination, which indicates that calcination has a significant effect on the strength of the product.
Comparative example 2
A method for producing blocky calcium oxide by using carbide slag comprises the following steps:
step 1, adding water into a disodium hydrogen phosphate adhesive to obtain an adhesive aqueous solution.
Step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture; wherein, carbide slag: disodium hydrogen phosphate binder: the proportion of water is 100: 10: 60.
and 3, pressing and molding the mixture by adopting a mold under proper pressure (the mixture is divided into 3 samples, wherein the No. 1 sample is knocked for 4 times, the No. 2 sample is knocked for 6 times, and the No. 3 sample is knocked for 8 times), standing at room temperature, maintaining and drying for 12 hours, drying and dehydrating for 2 hours at 105 ℃, naturally cooling to about 50 ℃, transferring into a dryer, and preventing water absorption from decomposing to obtain 3 blocky calcium oxides which are respectively a test piece 1, a test piece 2 and a test piece 3.
The strength of the obtained 3 blocks of calcium oxide is tested by an electronic universal tester with the model number of UTM5105, the loading speed of the electronic universal tester is 0.5mm/min, the maximum load of the test piece 1 is 20.51N, the maximum load of the test piece 2 is 20.83N, the maximum load of the test piece 3 is 20.97N,
as can be seen from the data of example 5 and comparative example 2, the strength difference of the samples before calcination is small under different molding conditions, and the strength difference is obviously increased after calcination, which indicates that calcination has a significant effect on the strength of the product.
In the above embodiment, the compressive strength of the calcium oxide pellet can be controlled by controlling the molding pressure, the addition amount of the binder and the addition amount of water during the molding process of the calcium oxide pellet. Wherein, the forming pressure plays the effect of destroying the "arch bridge effect" that frictional force and mechanical interlock force formed between the powder granule, makes the granule rearrange, improves the mechanical meshing effect between the granule, increases the area of contact between the powder, improves the pellet density, and then strengthens the compressive strength of pellet.
The water plays a role of lubricating particles in the pellet forming process, so that the friction force among the particles can be reduced, the contact among the pellet particles is more compact, and the pellet strength is favorably improved. Generally, the raw material has high moisture, the initial balling is fast, but raw balls are easy to bond and deform and are difficult to demould, so that the raw balls have uneven particle size distribution and poor strength, and the drying cost is increased. And the phenomena of increased gap between two hemispheres, poor powder bonding strength, low balling rate and even incapability of balling easily occur when the water content of the raw material is too low.
The phosphoric acid series binding agent can form fibrous crystals to be inserted among CaO particles at high temperature, and the existence of the fibrous crystals obviously improves the compressive strength of the CaO carbon-containing pellets.
Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. A method for producing blocky calcium oxide by using carbide slag is characterized by comprising the following steps:
step 1, adding water into an adhesive to obtain an adhesive aqueous solution;
step 2, adding a binder aqueous solution into the carbide slag, and uniformly mixing to obtain a mixture;
and 3, pressing and forming the mixture, drying at room temperature, drying, and calcining to obtain the catalyst.
2. The method for producing bulk calcium oxide by using carbide slag according to claim 1, wherein the carbide slag, the binder and the water are used in a ratio of (85-100): (9-15): 60.
3. the method for producing bulk calcium oxide using carbide slag according to claim 1, further comprising adding blue carbon to the carbide slag before adding the aqueous binder solution to the carbide slag.
4. The method for producing bulk calcium oxide using carbide slag according to claim 1, wherein in step 1, the binder is inorganic sodium silicate, a mixture of phosphoric acid and silicate, sodium dihydrogen phosphate, or disodium hydrogen phosphate.
5. The method for producing bulk calcium oxide from carbide slag according to claim 4, wherein in step 1, the binder is sodium dihydrogen phosphate or disodium hydrogen phosphate.
6. The method for producing bulk calcium oxide using carbide slag according to claim 1, wherein the number of press-molding in step 3 is 2 to 10.
7. The method for producing bulk calcium oxide using carbide slag according to claim 1, wherein the room temperature drying time in step 3 is 12 to 24 hours.
8. The method for producing bulk calcium oxide by using carbide slag as claimed in claim 1, wherein the drying temperature in step 3 is 100-110 ℃, and the drying time is 1-3 hours.
9. The method for producing bulk calcium oxide using carbide slag as claimed in claim 1, wherein in step 3, the calcination temperature is 800-1100 ℃, the calcination time is 40-80min, and the temperature-raising speed of calcination is 10-22 ℃/min.
10. The method for producing bulk calcium oxide using carbide slag according to claim 9, wherein in step 3, the temperature of the calcination is 900 ℃ and the temperature increase rate of the calcination is 16 ℃/min.
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