CN113755152A - Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore - Google Patents
Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore Download PDFInfo
- Publication number
- CN113755152A CN113755152A CN202111175554.1A CN202111175554A CN113755152A CN 113755152 A CN113755152 A CN 113755152A CN 202111175554 A CN202111175554 A CN 202111175554A CN 113755152 A CN113755152 A CN 113755152A
- Authority
- CN
- China
- Prior art keywords
- resin
- ceramsite
- aggregate
- slag
- smelting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003795 chemical substances by application Substances 0.000 title claims abstract description 65
- 239000002699 waste material Substances 0.000 title claims abstract description 42
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000003723 Smelting Methods 0.000 title claims abstract description 23
- 229910052759 nickel Inorganic materials 0.000 title claims abstract description 23
- 239000002893 slag Substances 0.000 claims abstract description 73
- 229910000863 Ferronickel Inorganic materials 0.000 claims abstract description 53
- 239000002245 particle Substances 0.000 claims abstract description 46
- 239000000843 powder Substances 0.000 claims abstract description 29
- 239000011812 mixed powder Substances 0.000 claims abstract description 22
- 238000005245 sintering Methods 0.000 claims abstract description 18
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 17
- 239000000203 mixture Substances 0.000 claims abstract description 16
- RGPUVZXXZFNFBF-UHFFFAOYSA-K diphosphonooxyalumanyl dihydrogen phosphate Chemical compound [Al+3].OP(O)([O-])=O.OP(O)([O-])=O.OP(O)([O-])=O RGPUVZXXZFNFBF-UHFFFAOYSA-K 0.000 claims abstract description 12
- 229910052634 enstatite Inorganic materials 0.000 claims abstract description 12
- 239000008187 granular material Substances 0.000 claims abstract description 12
- 229920003063 hydroxymethyl cellulose Polymers 0.000 claims abstract description 12
- 229940031574 hydroxymethyl cellulose Drugs 0.000 claims abstract description 12
- BBCCCLINBSELLX-UHFFFAOYSA-N magnesium;dihydroxy(oxo)silane Chemical compound [Mg+2].O[Si](O)=O BBCCCLINBSELLX-UHFFFAOYSA-N 0.000 claims abstract description 12
- 238000012216 screening Methods 0.000 claims abstract description 12
- 229920005989 resin Polymers 0.000 claims description 67
- 239000011347 resin Substances 0.000 claims description 67
- 238000003756 stirring Methods 0.000 claims description 34
- 239000007822 coupling agent Substances 0.000 claims description 32
- 239000004014 plasticizer Substances 0.000 claims description 32
- 239000000314 lubricant Substances 0.000 claims description 29
- 238000005303 weighing Methods 0.000 claims description 26
- 229910001570 bauxite Inorganic materials 0.000 claims description 16
- 238000001816 cooling Methods 0.000 claims description 16
- 239000003822 epoxy resin Substances 0.000 claims description 14
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 claims description 14
- 229920000647 polyepoxide Polymers 0.000 claims description 14
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 10
- 239000005011 phenolic resin Substances 0.000 claims description 8
- NIQCNGHVCWTJSM-UHFFFAOYSA-N Dimethyl phthalate Chemical group COC(=O)C1=CC=CC=C1C(=O)OC NIQCNGHVCWTJSM-UHFFFAOYSA-N 0.000 claims description 6
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical group C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 claims description 6
- 229920001568 phenolic resin Polymers 0.000 claims description 6
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 5
- 238000010583 slow cooling Methods 0.000 claims description 4
- VILCJCGEZXAXTO-UHFFFAOYSA-N 2,2,2-tetramine Chemical compound NCCNCCNCCN VILCJCGEZXAXTO-UHFFFAOYSA-N 0.000 claims description 3
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical group [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 claims description 3
- 235000013539 calcium stearate Nutrition 0.000 claims description 3
- 239000008116 calcium stearate Substances 0.000 claims description 3
- FBSAITBEAPNWJG-UHFFFAOYSA-N dimethyl phthalate Natural products CC(=O)OC1=CC=CC=C1OC(C)=O FBSAITBEAPNWJG-UHFFFAOYSA-N 0.000 claims description 3
- 229960001826 dimethylphthalate Drugs 0.000 claims description 3
- 235000010299 hexamethylene tetramine Nutrition 0.000 claims description 3
- 239000004312 hexamethylene tetramine Substances 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 229960001124 trientine Drugs 0.000 claims description 3
- BPSIOYPQMFLKFR-UHFFFAOYSA-N trimethoxy-[3-(oxiran-2-ylmethoxy)propyl]silane Chemical group CO[Si](OC)(OC)CCCOCC1CO1 BPSIOYPQMFLKFR-UHFFFAOYSA-N 0.000 claims description 2
- 229910001710 laterite Inorganic materials 0.000 claims 1
- 239000011504 laterite Substances 0.000 claims 1
- 239000002994 raw material Substances 0.000 abstract description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 10
- 238000002360 preparation method Methods 0.000 abstract description 9
- 239000006004 Quartz sand Substances 0.000 abstract description 8
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 6
- 239000000919 ceramic Substances 0.000 abstract description 4
- 238000005265 energy consumption Methods 0.000 abstract description 4
- 241001391944 Commicarpus scandens Species 0.000 abstract description 3
- 238000007873 sieving Methods 0.000 description 7
- 239000002440 industrial waste Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 239000003921 oil Substances 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000005469 granulation Methods 0.000 description 3
- 230000003179 granulation Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 2
- 239000013630 prepared media Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- MTEZSDOQASFMDI-UHFFFAOYSA-N 1-trimethoxysilylpropan-1-ol Chemical compound CCC(O)[Si](OC)(OC)OC MTEZSDOQASFMDI-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 229910052839 forsterite Inorganic materials 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/80—Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention relates to a method for preparing a fracturing propping agent by using waste residues generated by smelting laterite-nickel ore, which comprises the following steps: crushing the ferronickel lump slag into ferronickel slag powder with a first preset granularity; taking 6-8 parts of ferronickel slag powder, adding 1-2 parts of an aluminum-containing mixture, 0.5-1 part of aluminum dihydrogen phosphate, 0.5-1 part of enstatite and 0.5-1 part of hydroxymethyl cellulose to form mixed powder; granulating by using the mixed powder, and screening out particles with a second preset particle size; sintering the granules into ceramsite aggregate. Compared with the traditional quartz sand proppant, the main raw material of the ceramsite aggregate is the ferronickel slag, the source is wide, the resource is rich and easy to obtain, and the formed fracturing proppant has high strength and is not easy to break. Compared with the traditional ceramic proppant, the preparation process is simplified, the energy consumption is lower, the raw material cost is also lower, the manufacturing cost is greatly reduced, and the water fracturing cost of an oil-gas well is further reduced.
Description
Technical Field
The invention relates to the technical field of recycling of waste residues produced by smelting of laterite-nickel ore, in particular to a method for preparing a fracturing propping agent by using waste residues produced by smelting of laterite-nickel ore.
Background
Waste residues are produced after smelting ferronickel from laterite-nickel ores, and the main components of the waste residues comprise forsterite, silicon dioxide, magnesium oxide, aluminum oxide and the like. Because the content of magnesium oxide in the waste residue is high, the waste residue is not suitable to be used as an additive of a building material, so that a large-scale consumption way is lacked, the waste residue is stored in a large amount, a large amount of land resources are occupied, and a certain environmental pollution risk is realized.
The domestic mainstream fracturing propping agents mainly comprise two types, namely quartz sand propping agents and ceramsite propping agents. The quartz sand proppant has low strength, is easy to crush, has low sphericity and surface finish, and is not beneficial to oil guide permeation. Therefore, quartz sand is only suitable for hydraulic fracturing of shallow wells and low closure pressure hydrocarbon reservoirs. In addition, in recent years, the exploitation of the quartz sand is also strictly controlled, so that the supply of the quartz sand is in short supply. The ceramsite proppant takes high-grade bauxite as a main raw material and takes ceramsite as a mixture. The production process has long route and complex production flow. Moreover, the high-grade bauxite has a high price, so that the manufacturing cost of the proppant is high, and the fracturing cost is further increased sharply. In addition, the high-grade bauxite is a mineral resource with strategic value, and a large amount of ceramsite is deeply buried under the ground surface due to the fracturing operation, so that the waste of the ceramsite resource is caused.
Therefore, how to prepare the fracturing propping agent by utilizing waste residues generated by smelting the laterite-nickel ore becomes a technical problem to be solved urgently in the field.
Disclosure of Invention
In order to solve the problem that waste residues generated by smelting of the laterite-nickel ore cannot be reasonably utilized to prepare the fracturing propping agent, the invention provides a method for preparing the fracturing propping agent by utilizing the waste residues generated by smelting of the laterite-nickel ore.
The method for preparing the fracturing propping agent by using the waste residues generated by smelting the laterite-nickel ore comprises the following steps:
crushing the ferronickel lump slag into ferronickel slag powder with a first preset granularity;
taking 6-8 parts of ferronickel slag powder, adding 1-2 parts of an aluminum-containing mixture, 0.5-1 part of aluminum dihydrogen phosphate, 0.5-1 part of enstatite and 0.5-1 part of hydroxymethyl cellulose to form mixed powder;
granulating by using the mixed powder, and screening out particles with a second preset particle size;
sintering the granules into ceramsite aggregate.
In one embodiment, the method further comprises the following steps:
and continuously stirring the ceramsite aggregate, and sequentially adding resin, a coupling agent, a plasticizer, a curing agent and a lubricant into the ceramsite aggregate to form the coated ceramsite proppant.
In one embodiment, the method for continuously stirring the ceramsite aggregate and sequentially adding the resin, the coupling agent, the plasticizer, the curing agent and the lubricant into the ceramsite aggregate to form the coated ceramsite proppant comprises the following steps:
the weight ratio of resin to ceramsite aggregate is (2-10): 100, weighing resin and ceramsite aggregate;
according to the weight of the weighed resin, the weight ratio of the coupling agent to the resin is (0.1-1.2): 100, weighing a coupling agent;
according to the weight of the weighed resin, the weight ratio of the plasticizer to the resin is (1-10): 100, weighing a plasticizer;
according to the weight of the weighed resin, the weight ratio of the curing agent to the resin is (1-8): 100, weighing a curing agent;
according to the weight of the weighed resin, the weight ratio of the lubricant to the resin is (1-6): 100, weighing a lubricant;
at a preset temperature, sequentially adding the coupling agent, the resin and the plasticizer in the amount into the ceramsite aggregate, uniformly mixing, then adding the curing agent in the amount into the ceramsite aggregate, and then adding the lubricant in the amount into the ceramsite aggregate to form a coated ceramsite proppant; and screening the coated ceramsite proppant with a third preset granularity for later use after cooling.
In one embodiment, the first predetermined particle size is less than 325 mesh;
the second preset granularity is 20-70 meshes;
the third preset granularity is 20-40 meshes.
In one embodiment, before the ferronickel slag is crushed into ferronickel slag powder with a first preset granularity, the ferronickel slag is treated by a hot-splashing slow cooling method to form ferronickel lump slag.
In one embodiment, the granules are dried at 105 ℃ for 24 hours before sintering the granules into a ceramsite aggregate.
In one embodiment, the aluminum-containing mixture is a low grade bauxite;
the mass fraction of aluminum in the low-grade bauxite is 40-60%;
in one embodiment, the aluminum-containing mixture is alumina-containing waste;
the mass fraction of alumina in the waste is more than 50 percent.
In one embodiment, the sintering temperature is 1000-1300 ℃, and the sintering time is 60-150 min.
In one embodiment, the coupling agent is gamma-glycidoxypropyltrimethoxysilane;
the resin is at least one of phenolic resin and epoxy resin;
the plasticizer is dimethyl phthalate;
the curing agent is hexamethylenetetramine or triethylene tetramine;
the lubricant is calcium stearate.
The invention has the beneficial effects that: the method for preparing the fracturing propping agent by using the waste residues generated by smelting the laterite-nickel ore takes the industrial waste nickel-iron residues as the main raw material and the aluminum-containing mixture as the auxiliary raw material to prepare the fracturing propping agent. The industrial waste nickel-iron slag has certain mechanical strength and acid resistance, and the prepared medium-density medium-strength fracturing propping agent can completely replace the traditional ceramsite propping agent through quenching and tempering modification. In the preparation process of the fracturing propping agent, a large amount of industrial waste nickel-iron slag is consumed, the harm of the nickel-iron slag to the environment is eliminated, and the sustainable development of the nickel-iron production industry is promoted. Compared with the traditional quartz sand proppant, the formed fracturing proppant has the advantages that the main raw material is the ferronickel slag, the source is wide, the resource is rich and easy to obtain, the formed fracturing proppant has high strength, is not easy to break, has good sphericity and is beneficial to oil guide permeation. Compared with the traditional ceramic proppant, the formed fracturing proppant has the advantages of simplified preparation process, lower energy consumption, lower raw material cost, greatly reduced manufacturing cost and further reduced water fracturing cost of oil and gas wells.
Drawings
FIG. 1 is a flow chart of a specific embodiment of the method for preparing a fracturing propping agent by using waste residues generated by smelting laterite-nickel ore.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention, but it is to be understood that the description is intended to illustrate further features and advantages of the invention, and not to limit the scope of the claims.
Referring to fig. 1, the invention provides a method for preparing a fracturing propping agent by using waste residues generated by smelting laterite-nickel ore, which comprises the following steps:
s100, crushing the ferronickel lump slag into ferronickel slag powder with a first preset granularity.
In this step, the first predetermined particle size is smaller than 325 mesh, i.e. the ferronickel lump slag is crushed into ferronickel slag powder with a particle size smaller than 325 mesh. So that the ferronickel slag powder, the aluminum-containing mixture and the binder can be fully mixed uniformly, and granulation molding is facilitated.
S200, taking 6-8 parts of nickel-iron slag powder, adding 1-2 parts of an aluminum-containing mixture, 0.5-1 part of aluminum dihydrogen phosphate, 0.5-1 part of enstatite and 0.5-1 part of hydroxymethyl cellulose to form mixed powder.
In this step, the above amount of the aluminum-containing mixture, the above amount of aluminum dihydrogen phosphate, the above amount of enstatite, and the above amount of hydroxymethyl cellulose are added to the above amount of the ferronickel slag powder to form a mixed powder. The powder was mixed for granulation. Wherein, the ferronickel slag powder is used as a main raw material, and the aluminum-containing mixture is used as an auxiliary raw material. Aluminum dihydrogen phosphate, enstatite and hydroxymethyl cellulose are used as binders, so that material balling is facilitated, and the strength of the formed fracturing propping agent can be effectively improved.
And S300, granulating by using the mixed powder, and screening out granules with a second preset granularity.
In this step, the mixed powder is granulated by a pan granulator or a round pot granulator. Then, the particles are screened to screen out particles of a second preset particle size. Here, it should be noted that the second predetermined particle size is 20 to 70 mesh. The granulating process includes that the turntable rotates at a high speed to throw out molten liquid drops, the moving direction of melt particles is changed under the action of a cyclone field in the granulating chamber to enable the melt particles to be approximately in collision contact with the inner wall along the circumferential direction of the inner wall of the middle ring segment to perform heat exchange cooling and break the particles into balls, and particles with consistent particle sizes are formed.
S400, sintering the particles into ceramsite aggregate.
In the step, the particles with the particle size of 20-70 meshes are sintered into the ceramsite aggregate at the temperature of 1000-1300 ℃. The sintering time is 60-150 min. The formed ceramsite aggregate can be directly used as a fracturing propping agent.
In the whole, industrial waste nickel-iron slag is used as a main raw material, and an aluminum-containing mixture is used as an auxiliary raw material to prepare the fracturing propping agent. The industrial waste nickel-iron slag has certain mechanical strength and acid resistance, and the prepared medium-density medium-strength fracturing propping agent can completely replace the traditional ceramsite propping agent through quenching and tempering modification. In the preparation process of the fracturing propping agent, a large amount of industrial waste nickel-iron slag is consumed, the harm of the nickel-iron slag to the environment is eliminated, and the sustainable development of the nickel-iron production industry is promoted. Compared with the traditional quartz sand proppant, the formed fracturing proppant has the advantages that the main raw material is the ferronickel slag, the source is wide, the resource is rich and easy to obtain, the formed fracturing proppant has high strength, is not easy to break, has good sphericity and is beneficial to oil guide permeation. Compared with the traditional ceramic proppant, the formed fracturing proppant has the advantages of simplified preparation process, lower energy consumption, lower raw material cost, greatly reduced manufacturing cost and further reduced water fracturing cost of oil and gas wells.
In an embodiment of the present invention, the method further includes the following steps:
s500, continuously stirring the ceramsite aggregate, and sequentially adding resin, a coupling agent, a plasticizer, a curing agent and a lubricant into the ceramsite aggregate to form the coated ceramsite proppant.
In the process, the resin can tightly coat the ceramsite aggregate. The coupling agent can be used as a bridge to firmly bond the resin and the ferronickel slag, and the bonding strength of the resin and the ceramsite is enhanced. The curing agent makes the resin perform a curing reaction to generate a product with a three-dimensional network structure so as to improve the mechanical strength and the chemical resistance. The plasticizer effectively improves the toughness of the resin and reduces the brittleness of the resin.
On the whole, firstly, the ferronickel slag powder is granulated, then the granules are sintered into ceramsite aggregate, and then the ceramsite aggregate is coated with a film. The ceramsite aggregate is tightly coated by resin with certain strength and toughness to form the coated ceramsite proppant. The formed film-coated ceramsite proppant has proper strength and low breaking rate.
Specifically, S500, continuously stirring the ceramsite aggregate, and sequentially adding resin, a coupling agent, a plasticizer, a curing agent and a lubricant into the ceramsite aggregate to form the coated ceramsite proppant comprises the following steps:
the weight ratio of resin to ceramsite aggregate is (2-10): and 100, weighing resin and ceramsite aggregate. According to the weight of the weighed resin, the weight ratio of the coupling agent to the resin is (0.1-1.2): 100, weighing the coupling agent. According to the weight of the weighed resin, the weight ratio of the plasticizer to the resin is (1-10): 100, weighing the plasticizer. According to the weight of the weighed resin, the weight ratio of the curing agent to the resin is (1-8): 100, weighing the curing agent. According to the weight of the weighed resin, the weight ratio of the lubricant to the resin is (1-6): 100, weighing the lubricant. Here, it is to be noted that the order of weighing the coupling agent, the plasticizer, the curing agent, and the lubricant is not required.
After the resin, the ceramsite aggregate, the coupling agent, the plasticizer, the curing agent and the lubricant are weighed, sequentially adding the coupling agent, the resin and the plasticizer into the ceramsite aggregate in the amount at a preset temperature, uniformly mixing the coupling agent, the resin and the plasticizer, then adding the curing agent into the ceramsite aggregate in the amount, and then adding the lubricant into the ceramsite aggregate in the amount to form the coated ceramsite proppant. And screening the coated ceramsite proppant with a third preset granularity for later use after cooling. It should be noted that the preset temperature is 190-. Specifically, the ceramsite aggregate is continuously stirred at the temperature of 190-210 ℃, and the resin is firstly added into the ceramsite aggregate. And after stirring for 30-300s, adding a coupling agent into the ceramsite aggregate. And after stirring for 30-300s, adding a plasticizer into the ceramsite aggregate. And after stirring for 5-10min, adding a curing agent into the ceramsite aggregate to cure the resin. Before the ceramsite aggregate is agglomerated, a lubricant is added into the ceramsite aggregate to prevent adhesion. And then stirring for 2-3min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
In an embodiment of the present invention, before the ferronickel slag is crushed into the ferronickel slag powder with the first predetermined particle size, S600, the ferronickel slag is processed by a hot-splashing slow-cooling method to form ferronickel slag blocks.
In the process, hot splashing treatment is firstly carried out on the waste slag, then water is sprayed to cool the waste slag, and then the waste slag is crushed into appropriately compact ferronickel lump slag.
In a specific embodiment of the invention, the granules are dried at 105 ℃ for 24 hours S700 before sintering the granules into ceramsite aggregates. Therefore, the dryness of the particles can be improved, and the particles are favorably sintered into ceramsite aggregate.
In a specific embodiment of the invention, before adding the resin into the ceramsite aggregate, the ceramsite aggregate is heated to 260 ℃ along with 250 ℃, and after the temperature is kept for 2-3min, the ceramsite aggregate is naturally cooled to 210 ℃ along with 190 ℃. Therefore, the water can be effectively removed, the resin, the coupling agent and the plasticizer have better fluidity, and the smooth operation of the film covering process is facilitated.
In one embodiment of the invention, the aluminum-containing mixture is low grade bauxite or alumina-containing waste. Wherein, the mass fraction of aluminum in the low-grade bauxite is 40-60%, and the mass fraction of aluminum oxide in the waste is more than 50%. Here, the waste containing alumina is red mud, fly ash from thermal power plants, waste ceramic rolls, or the like.
In a specific embodiment of the invention, the coupling agent is gamma-glycidyl ether oxypropyltrimethoxysilane, the resin is at least one of phenolic resin and epoxy resin, the plasticizer is dimethyl phthalate, the curing agent is hexamethylenetetramine or triethylenetetramine, and the lubricant is calcium stearate. In other embodiments, the resin is a mixture of phenolic and epoxy resins, wherein the weight ratio of phenolic to epoxy resins is 2: 1.
in a specific embodiment of the invention, the coated ceramsite proppant is used as a fracturing proppant, and the preparation process comprises the following steps:
firstly, the ferronickel slag is treated by a hot splashing slow cooling method to form ferronickel slag blocks. Then, the ferronickel lump slag is crushed into ferronickel slag powder with a first preset granularity. Then, taking 6-8 parts of ferronickel slag powder by weight, and adding 1-2 parts of low-grade bauxite or waste containing alumina, 0.5-1 part of aluminum dihydrogen phosphate, 0.5-1 part of enstatite and 0.5-1 part of hydroxymethyl cellulose to form mixed powder. Then, the mixed powder is used for granulation through a disc granulator or a round pot granulator, and granules with the granularity of 20-70 meshes are screened out. Thereafter, the granules having a particle size of 20-70 mesh were dried at 105 ℃ for 24 h. Then, sintering the dried particles at the temperature of 1000-1300 ℃, and keeping the temperature for 60-120min to prepare the ceramsite aggregate. Then, according to the weight ratio of the resin to the ceramsite aggregate (2-10): and 100, weighing resin and ceramsite aggregate. According to the weight of the weighed resin, the weight ratio of the coupling agent to the resin is (0.1-1.2): 100, weighing the coupling agent. According to the weight of the weighed resin, the weight ratio of the plasticizer to the resin is (1-10): 100, weighing the plasticizer. According to the weight of the weighed resin, the weight ratio of the curing agent to the resin is (1-8): 100, weighing the curing agent. According to the weight of the weighed resin, the weight ratio of the lubricant to the resin is (1-6): 100, weighing the lubricant. Then, the ceramsite aggregate is heated to the temperature of 250-260 ℃ to remove water, and after the constant temperature is kept for 2-3min, the ceramsite aggregate is naturally cooled to the temperature of 190-210 ℃. Then, at the temperature of 190-. And after stirring for 30-300s, adding a coupling agent into the ceramsite aggregate. And after stirring for 30-300s, adding a plasticizer into the ceramsite aggregate. And after stirring for 5-10min, adding a curing agent into the ceramsite aggregate to cure the resin. Before the ceramsite aggregate is agglomerated, a lubricant is added into the ceramsite aggregate to prevent adhesion. And then stirring for 2-3min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 1
(1) Crushing the ferronickel lump slag into ferronickel slag powder with the granularity smaller than 325 meshes;
(2) taking 6 parts of nickel-iron slag powder, and adding 1 part of low-grade bauxite, 1 part of aluminum dihydrogen phosphate, 1 part of enstatite and 1 part of hydroxymethyl cellulose to form mixed powder. Then, granulating by using the mixed powder through a disc granulator or a round pot granulator, and screening out particles with the particle size of 20-40 meshes;
(3) sintering the screened particles at 1100 ℃, and keeping the temperature for 60min to prepare ceramsite aggregate;
(4) weighing 1000g of ceramsite aggregate, heating to 250 ℃, keeping the temperature for 2min, cooling to 190 ℃, quickly stirring, sequentially adding 20g of epoxy resin, 0.02g of coupling agent and 0.2g of plasticizer while stirring, uniformly stirring for 5min, adding 0.2g of curing agent to cure the epoxy resin, adding 0.2g of lubricant before particles are agglomerated to prevent adhesion, continuously stirring for 2min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 2
(1) Crushing the ferronickel lump slag into ferronickel slag powder with the granularity smaller than 325 meshes;
(2) according to the weight portion, 8 portions of ferronickel slag powder is taken, and 2 portions of low-grade bauxite, 0.5 portion of aluminum dihydrogen phosphate, 0.5 portion of enstatite and 0.5 portion of hydroxymethyl cellulose are added to form mixed powder. Then, granulating by using the mixed powder through a disc granulator or a round pot granulator, and screening out particles with the particle size of 50-70 meshes;
(3) sintering the screened particles at 1300 ℃, and keeping the temperature for 120min to prepare ceramsite aggregate;
(4) weighing 1000g of ceramsite aggregate, heating to 260 ℃, keeping the temperature for 3min, cooling to 210 ℃, quickly stirring, sequentially adding 100g of epoxy resin, 1.2g of coupling agent and 10g of plasticizer while stirring, uniformly stirring for 10min, adding 8g of curing agent to cure the epoxy resin, adding 6g of lubricant before the particles are agglomerated to prevent adhesion, continuously stirring for 3min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 3
(1) Crushing the ferronickel lump slag into ferronickel slag powder with the granularity smaller than 325 meshes;
(2) taking 7 parts of ferronickel slag powder, adding 1.5 parts of low-grade bauxite, 0.75 part of aluminum dihydrogen phosphate, 0.75 part of enstatite and 0.75 part of hydroxymethyl cellulose to form mixed powder. Then, granulating by using the mixed powder through a disc granulator or a round pot granulator, and screening out particles with the particle size of 20-40 meshes;
(3) sintering the screened particles at 1200 ℃, and keeping the temperature for 90min to prepare ceramsite aggregate;
(4) weighing 1000g of ceramsite aggregate, heating to 255 ℃, keeping the temperature for 2.5min, cooling the temperature to 200 ℃, quickly stirring, sequentially adding 50g of epoxy resin, 1.2g of coupling agent and 10g of plasticizer while stirring, uniformly stirring for 8min, adding 8g of curing agent to cure the epoxy resin, adding 6g of lubricant before particles are agglomerated to prevent adhesion, continuously stirring for 2.5min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 4
The same as example 3, except that: the low grade bauxite is replaced by waste containing alumina.
Example 5
(1) Crushing the ferronickel lump slag into ferronickel slag powder with the granularity smaller than 325 meshes;
(2) taking 7 parts of ferronickel slag powder, adding 1.5 parts of low-grade bauxite, 0.75 part of aluminum dihydrogen phosphate, 0.75 part of enstatite and 0.75 part of hydroxymethyl cellulose to form mixed powder. Then, granulating by using the mixed powder through a disc granulator or a round pot granulator, and screening out particles with the particle size of 20-40 meshes;
(3) sintering the screened particles at 1200 ℃, and keeping the temperature for 90min to prepare ceramsite aggregate;
(4) weighing 1000g of ceramsite aggregate, heating to 250 ℃, keeping the temperature for 3min, cooling to 210 ℃, quickly stirring, sequentially adding 50g of epoxy resin, 0.25g of coupling agent and 2.5g of plasticizer while stirring, uniformly stirring for 10min, adding 2.5g of curing agent to cure the epoxy resin, adding 2.5g of lubricant before particles are agglomerated to prevent adhesion, continuously stirring for 3min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 6
(1) Crushing the ferronickel lump slag into ferronickel slag powder with the granularity smaller than 325 meshes;
(2) taking 7 parts of ferronickel slag powder, adding 1.5 parts of waste containing alumina, 0.75 part of aluminum dihydrogen phosphate, 0.75 part of enstatite and 0.75 part of hydroxymethyl cellulose to form mixed powder. Then, granulating by using the mixed powder through a disc granulator or a round pot granulator, and screening out particles with the particle size of 30-50 meshes;
(3) sintering the screened particles at 1300 ℃, and keeping the temperature for 120min to prepare ceramsite aggregate;
(4) weighing 1000g of ceramsite aggregate, heating to 250 ℃, keeping the temperature for 3min, cooling to 210 ℃, quickly stirring, sequentially adding 100g of phenolic resin, 0.5g of coupling agent and 5g of plasticizer while stirring, uniformly stirring for 10min, adding 5g of curing agent to cure the phenolic resin, adding 5g of lubricant before the particles are agglomerated to prevent adhesion, continuously stirring for 3min, cooling and sieving to obtain the coated ceramsite proppant with the granularity of 20-40 meshes.
Example 7
The same as example 3, except that: 60g of phenol resin and 30g of epoxy resin were used instead of 100g of phenol resin.
The fracturing proppants prepared in the above examples and comparative example 1 were subjected to performance tests, and the test results are shown in the following table:
| bulk Density (g/cm)3) | Apparent density (g/cm)3) | Breaking rate at 69MPa | |
| Example 1 | 1.89 | 2.90 | ≤9.06％ |
| Example 2 | 1.92 | 2.93 | ≤8.73％ |
| Example 3 | 1.89 | 2.88 | ≤8.36％ |
| Example 4 | 1.89 | 2.91 | ≤8.25％ |
| Example 5 | 1.86 | 2.90 | ≤7.57％ |
| Example 6 | 1.9 | 2.93 | ≤8.43％ |
| Example 7 | 1.89 | 2.90 | ≤8.35％ |
As can be seen from the above table, the bulk density of the fracturing proppant prepared in examples 1-7 is 1.86-1.92g/cm3Apparent density of 2.88-2.93g/cm3The breaking rate under 69MPa is less than or equal to 9.06 percent, and the national strength requirement is met. The fracturing proppant prepared by the preparation method of the fracturing proppant provided by the invention has moderate strength and density, and meets the requirements of national standards; the main raw material nickel-iron slag is solid waste, can effectively replace the original ceramsite aggregate and high-alumina bauxite, reduces the preparation cost of the proppant, solves the problem of environmental pollution, and has simple preparation process and low energy consumption.
In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," "one specific embodiment," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic representation of the term does not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the scope of the present invention by equivalent replacement or change according to the technical solution and the inventive concept of the present invention within the scope of the present disclosure.
Claims (10)
1. A method for preparing a fracturing propping agent by using waste residues generated by smelting laterite-nickel ore is characterized by comprising the following steps:
crushing the ferronickel lump slag into ferronickel slag powder with a first preset granularity;
taking 6-8 parts by weight of the nickel-iron slag powder, and adding 1-2 parts by weight of an aluminum-containing mixture, 0.5-1 part by weight of aluminum dihydrogen phosphate, 0.5-1 part by weight of enstatite and 0.5-1 part by weight of hydroxymethyl cellulose to form mixed powder;
granulating by using the mixed powder, and screening out granules with a second preset granularity;
and sintering the granules into ceramsite aggregate.
2. The method for preparing the fracturing propping agent by using the waste slag generated by smelting the lateritic nickel ores according to the claim 1, is characterized by further comprising the following steps:
and continuously stirring the ceramsite aggregate, and sequentially adding resin, a coupling agent, a plasticizer, a curing agent and a lubricant into the ceramsite aggregate to form the coated ceramsite proppant.
3. The method for preparing the fracturing propping agent by using the waste residues generated by smelting the lateritic nickel ores according to the claim 2, wherein the continuously stirring the ceramsite aggregate and sequentially adding the resin, the coupling agent, the plasticizer, the curing agent and the lubricant into the ceramsite aggregate to form the film-coated ceramsite propping agent comprises the following steps:
the weight ratio of the resin to the ceramsite aggregate is (2-10): 100, weighing the resin and the ceramsite aggregate;
according to the weight of the weighed resin, the weight ratio of the coupling agent to the resin is (0.1-1.2): 100, weighing the coupling agent;
according to the weighed weight of the resin, the weight ratio of the plasticizer to the resin is (1-10): 100, weighing the plasticizer;
according to the weighed weight of the resin, the weight ratio of the curing agent to the resin is (1-8): 100, weighing the curing agent;
according to the weighed weight of the resin, the weight ratio of the lubricant to the resin is (1-6): 100, weighing the lubricant;
at a preset temperature, sequentially adding the coupling agent, the resin and the plasticizer in the amount into the ceramsite aggregate in sequence, uniformly mixing, then adding the curing agent in the amount into the ceramsite aggregate, and then adding the lubricant in the amount into the ceramsite aggregate to form the film-coated ceramsite proppant; and screening the coated ceramsite proppant with a third preset granularity for later use after cooling.
4. The method for preparing the fracturing propping agent by using the waste slag generated by smelting of nickel laterite ores according to claim 3, wherein the first preset granularity is less than 325 meshes;
the second preset granularity is 20-70 meshes;
the third preset granularity is 20-40 meshes.
5. The method for preparing the fracturing propping agent by using the waste slag generated in the smelting of the lateritic nickel ore according to any one of the claims 1 to 4, characterized in that the ferronickel slag is treated by a hot-splashing slow cooling method to form the ferronickel lump slag before the ferronickel slag is crushed into ferronickel slag powder with a first preset granularity.
6. The method for preparing fracturing propping agent by using the waste slag generated by smelting of lateritic nickel ore according to any of the claims 1 to 4, characterized in that the particles are dried for 24h at 105 ℃ before sintering the particles into ceramsite aggregate.
7. The method for preparing fracturing propping agent by using waste slag from laterite-nickel ore smelting according to any one of claims 1 to 4, characterized in that the aluminum-containing mixture is low-grade bauxite;
the mass fraction of aluminum in the low-grade bauxite is 40-60%.
8. The method for preparing fracturing propping agent by using waste slag from laterite-nickel ore smelting according to any one of claims 1 to 4, characterized in that the aluminum-containing mixture is waste containing alumina;
the mass fraction of alumina in the waste is more than 50%.
9. The method for preparing the fracturing propping agent by using the waste residues generated by smelting of lateritic nickel ores according to any one of claims 1 to 4, characterized in that the sintering temperature is 1000-1300 ℃, and the sintering time is 60-150 min.
10. The method for preparing the fracturing propping agent by using the waste slag generated in the smelting of lateritic nickel ores according to the claim 3, characterized in that the coupling agent is gamma-glycidoxypropyltrimethoxysilane;
the resin is at least one of phenolic resin and epoxy resin;
the plasticizer is dimethyl phthalate;
the curing agent is hexamethylenetetramine or triethylene tetramine;
the lubricant is calcium stearate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111175554.1A CN113755152A (en) | 2021-10-09 | 2021-10-09 | Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111175554.1A CN113755152A (en) | 2021-10-09 | 2021-10-09 | Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113755152A true CN113755152A (en) | 2021-12-07 |
Family
ID=78798965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111175554.1A Pending CN113755152A (en) | 2021-10-09 | 2021-10-09 | Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113755152A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4678758A (en) * | 1983-02-11 | 1987-07-07 | Swiss Aluminum Ltd. | Porous ceramic filter body and manufacturing method therefor |
| CN104479665A (en) * | 2014-12-11 | 2015-04-01 | 杨松 | Petroleum proppant and preparation method thereof |
| CN107267134A (en) * | 2017-06-12 | 2017-10-20 | 太原理工大学 | It is a kind of for low-density fracturing propping agents of coal-bed gas exploitation and preparation method thereof |
| CN110759738A (en) * | 2018-07-27 | 2020-02-07 | 广东清大同科环保技术有限公司 | Steel slag ceramsite and preparation method thereof |
| CN110950641A (en) * | 2018-09-26 | 2020-04-03 | 广东清大同科环保技术有限公司 | Self-heat-release solid waste based ultralow-density proppant and preparation method thereof |
| CN112080270A (en) * | 2020-08-18 | 2020-12-15 | 北京中冶设备研究设计总院有限公司 | Preparation method of coated propping agent |
-
2021
- 2021-10-09 CN CN202111175554.1A patent/CN113755152A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4678758A (en) * | 1983-02-11 | 1987-07-07 | Swiss Aluminum Ltd. | Porous ceramic filter body and manufacturing method therefor |
| CN104479665A (en) * | 2014-12-11 | 2015-04-01 | 杨松 | Petroleum proppant and preparation method thereof |
| CN107267134A (en) * | 2017-06-12 | 2017-10-20 | 太原理工大学 | It is a kind of for low-density fracturing propping agents of coal-bed gas exploitation and preparation method thereof |
| CN110759738A (en) * | 2018-07-27 | 2020-02-07 | 广东清大同科环保技术有限公司 | Steel slag ceramsite and preparation method thereof |
| CN110950641A (en) * | 2018-09-26 | 2020-04-03 | 广东清大同科环保技术有限公司 | Self-heat-release solid waste based ultralow-density proppant and preparation method thereof |
| CN112080270A (en) * | 2020-08-18 | 2020-12-15 | 北京中冶设备研究设计总院有限公司 | Preparation method of coated propping agent |
Non-Patent Citations (1)
| Title |
|---|
| 万仁溥: "《采油技术手册 第9分册 压裂酸化工艺技术》", 31 January 1998, 石油工业出版社 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109277517B (en) | High-temperature-resistant ceramsite precoated sand for casting and preparation method thereof | |
| CN101906297B (en) | Method for preparing film-coated ceramisite proppant by using oil shale wastes | |
| CN105778886A (en) | Low-density high-strength ceramsite proppant and preparation process thereof | |
| CN113426942B (en) | Method for preparing precoated sand for cast steel from recycled material | |
| CN114349475B (en) | Preparation method of core-shell type ceramsite fracturing propping agent for oil and gas collection | |
| CN103521695A (en) | Molding sand for casting iron balls and preparation method of molding sand | |
| CN110950644A (en) | Steel slag sintered brick and preparation method thereof | |
| CN109534793B (en) | Low-density petroleum fracturing propping agent containing sapphirine crystals and preparation method thereof | |
| CN113755152A (en) | Method for preparing fracturing propping agent by using waste residues generated by smelting laterite-nickel ore | |
| CN107057676B (en) | Ceramic propping agent with composite structure and preparation method thereof | |
| CN103143672A (en) | Method for preparing water glass used for foundry by using waste sand of alkaline phenolic resin self-hardening sand | |
| CN109108211B (en) | Cold-process inorganic phosphate precoated sand and preparation method thereof | |
| CN109652055B (en) | Complex phase ceramsite petroleum fracturing propping agent containing sapphirine crystals and preparation method thereof | |
| WO2017091607A1 (en) | System and method for forming spherical silica-based proppant and pig iron utilizing mining slag | |
| CN112552895B (en) | Method for preparing petroleum fracturing propping agent based on molybdenum dressing tailings | |
| CN103495699A (en) | Molding sand for producing large supercritical cast steel and production method of molding sand | |
| CN111470850A (en) | Ceramsite proppant prepared from industrial waste copper smelting slag and preparation process | |
| CN114367629B (en) | High-temperature-resistant precoated sand and preparation method thereof | |
| CN104841853A (en) | Fast-radiating easy-to-collapse casting sand and preparation method thereof | |
| CN110981243A (en) | Preparation process for preparing granulated material by using blast furnace slag powder | |
| CN113402290B (en) | Method for preparing porous ceramic material by utilizing spodumene flotation tailings through low-temperature sintering | |
| KR20200136642A (en) | A double-coated proppant | |
| KR20200123940A (en) | A coated proppant | |
| KR20200116708A (en) | Coated proppant | |
| RU2783399C1 (en) | Method for obtaining proppant |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211207 |