Production method of a water-resistant honeycomb activated carbon

Abstract

The present invention relates to the technical field of activated carbon production, and specifically discloses a production method of water-resistant honeycomb activated carbon, which includes the following steps: 1) Mixing and preparing slurry: Select activated carbon powder with a passing rate of more than 90% through 200 meshes and a moisture content within 10% as raw materials, and inorganic binder with a passing rate of more than 95% through 200 meshes and a moisture content within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 5-1:1 to obtain a mixed slurry with a solid content of 15-30%, and add a boric acid modifier for co-assembly modification to enhance the adhesiveness, water resistance and activity of the honeycomb activated carbon. The present invention can use any kind of activated carbon powder as raw material, and the production and preparation method is simple. By selecting the activated carbon powder as raw material according to needs, the performance indexes of the honeycomb activated carbon can be arbitrarily and stably adjusted. High-strength water-resistant honeycomb activated carbon can be produced without affecting the adsorption indexes.

Description

Technical Field

[0001] The present invention relates to the technical field of activated carbon, and particularly relates to a production method of water-resistant honeycomb activated carbon. Background Art

[0002] Honeycomb activated carbon is honeycomb-shaped activated carbon, which has small air flow resistance and large adsorption capacity, and has great application potential in the fields of denitrification and desulfurization treatment of industrial flue gas, purification treatment of organic waste gas, recovery of organic solvents, gas purification and storage, and catalyst carriers. Currently, the coal-based honeycomb activated carbon has the highest market share. There are two types of honeycomb activated carbon: water-resistant and non-water-resistant. The water-resistant type requires high-temperature treatment. There are also two process routes for water-resistant honeycomb activated carbon, and basically continuous production cannot be achieved. One is obtained by using pulverized coal raw materials, organic binders, and inorganic binders as raw materials, through mixing, kneading, forming, drying, and high-temperature carbon activation. The other is obtained by using activated carbon powder, organic binders, and inorganic binders through mixing, kneading, forming, drying, and anoxic calcination. Both methods need to be treated at a high temperature above 800 °C to decompose the organic binder or organic components to obtain high-strength honeycomb activated carbon, but this also leads to further collapse of the structure and reduction of strength. At the same time, in order to ensure strength, the adsorption capacity will be sacrificed, and it is difficult to stably control important indicators such as the adsorption capacity, pore volume, pore size distribution, and specific surface area of the activated carbon, which seriously affects the application expansion of the product.

[0003] A honeycomb activated carbon and its manufacturing method with the application number CN201610735895.2, a bamboo vinegar honeycomb purification activated carbon and its preparation method with the application number CN201310351949.1, and a manufacturing method of honeycomb purification activated carbon with the application number CN201010541835.X. The above invention patents all use the preparation of activated carbon powder with organic and inorganic substances as raw materials, and the high-temperature treatment link is above 800 °C, which has disadvantages such as high energy consumption and large pollution caused by the decomposition of organic substances. At the same time, the product stability performance is poor, and under water resistance and high temperature, the adsorption and strength performance of the product become worse; based on this, the present invention further improves and optimizes it. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a production method of water-resistant honeycomb activated carbon to solve the problems mentioned in the above background art.

[0005] The present invention solves the technical problems by adopting the following technical solutions:

[0006] The present invention provides a production method of water-resistant honeycomb activated carbon, including the following steps:

[0007] 1) Mixed pulp preparation: Select activated carbon powder with a passing rate of over 90% through a 200-mesh sieve and moisture content within 10% as raw material, and an inorganic binder with a passing rate of over 95% through a 200-mesh sieve and moisture content within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 5 - 1:1 to obtain a mixed slurry with a solid content of 15 - 30%.

[0008] 2) High-pressure dehydration: Feed the mixed slurry from step 1) to a dehydrator through a feed pump. Ensure full feeding, and then conduct complete dehydration by high-pressure extrusion at 10 - 20 MPa or by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and returned to the stirring tank for pulp preparation. After dehydration, unload the material to obtain a mixed mud with a moisture content within 55% in the filter cake.

[0009] 3) Rough refining and forming: Convey the mixed mud from step 2) to a kneader through a belt for kneading for 30 - 60 minutes, and then discharge it to a belt and convey it to a cylindrical extruder for extrusion forming to obtain a roughly refined columnar mud.

[0010] 4) Fine refining and forming: Convey the roughly refined columnar mud from step 3) to a cylindrical extruder under a vacuum of -0.06 - -0.09 MPa through a belt for extrusion forming to obtain a finely refined columnar mud.

[0011] 5) Mould forming: Convey the finely refined columnar mud from step 4) to an extruder equipped with a honeycomb mould for extrusion forming, and then conduct automatic cutting to obtain a honeycomb-shaped wet material.

[0012] 6) Temperature rise and drying: Put the honeycomb-shaped wet material from step 5) into a drying room and conduct timed drying in three temperature sections of 30 - 40 °C, 40 - 50 °C, and 50 - 80 °C in sequence. After drying, the moisture content is within 5% to obtain a honeycomb-shaped dry material.

[0013] 7) Heat treatment: Put the honeycomb-shaped dry material from step 6) into a sealed and oxygen-deficient high-temperature furnace at 500 - 600 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for temperature rise and drying through a heat exchanger. Conduct heat treatment for 8 - 10 hours, and then naturally cool down to obtain honeycomb activated carbon.

[0014] Preferably, a boric acid modifier solution accounting for 1 - 5% of the total amount of the mixed slurry is further added to the mixed slurry.

[0015] Preferably, the preparation method of the boric acid modifier solution is as follows:

[0016] Add boric acid to the chitosan regulating solution according to a weight ratio of 1:5, and stir evenly to obtain a boric acid modifier.

[0017] Preferably, the chitosan regulating solution includes the following raw materials in parts by weight: 10 - 20 parts of chitosan, 30 - 40 parts of deionized water, 1 - 4 parts of lanthanum sulfate, and 2 - 5 parts of sodium alginate aqueous solution.

[0018] Preferably, the mass fraction of the sodium alginate aqueous solution is 20-30%.

[0019] Preferably, in step 1), the particle size of the activated carbon powder has a passing rate of over 90% through 200 mesh, the moisture content is within 10%, and the iodine value is 600-1300 mg / g; the inorganic binder is attapulgite clay, and the particle size of the inorganic clay has a passing rate of over 95% through 200 mesh and the moisture content is within 10%; the activated carbon powder and attapulgite clay are fed in a mass ratio of 3-1:1, and the solid content of the mixed slurry is 15-30%.

[0020] Preferably, the water content of the filter cake after high-pressure dehydration in step 2) is within 55%; in step 3), the kneading time of the kneader is 30-60 min;

[0021] In step 4), the vacuum degree of the vacuum pumping is -0.06 to -0.09 MPa.

[0022] Preferably, for the temperature-raising drying in step 6), it is dried at a temperature of 30-40°C for 1-2 days, dried at a temperature of 40-50°C for 1-2 days, and dried at a temperature of 50-80°C for 1 day, and the drying humidity is adjusted to slowly dry to reduce the breakage of the honeycomb-shaped wet material, and the water content after drying is within 5%.

[0023] Preferably, in step 7), the heat treatment temperature is 500-600°C, and the heat treatment time is 8-10 h;

[0024] In step 7), the iodine value of the honeycomb activated carbon can reach 800-1000 mg / g or more, and the carbon tetrachloride adsorption rate reaches 60-80%.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can use any kind of activated carbon powder and inorganic binder as raw materials, and the production and preparation method is simple. By selecting the activated carbon powder as the raw material as needed, the performance indexes of the honeycomb activated carbon can be arbitrarily and stably adjusted. Without affecting the adsorption indexes, high-strength and water-resistant honeycomb activated carbon can be produced.

[0027] 2. The heat treatment temperature of the present invention is relatively low, and the high-temperature tail gas does not contain tar and can be directly recycled and used as the heat source for low-temperature drying, saving energy and reducing consumption, and having low production cost and low pollution.

[0028] 3. The temperature-raising drying method of the present invention has a low breakage rate of the honeycomb activated carbon, a high honeycomb yield, and high strength.

[0029] 4. The technical production process of the present invention is simple, the production efficiency is high, it is easy to realize automation, and it is conducive to industrial promotion.

[0030] 5. When the binder of the present invention is combined with a boric acid modifier solution and activated carbon powder, the performance stability of the product is significantly improved. By using sodium alginate and chitosan regulating solution, etc., in coordination with boric acid for modification, the modified boric acid modifier solution can enhance the adsorption and strength stability of the product. The product remains stable in terms of water resistance and performance at high temperatures. At the same time, after pre-improving treatment, the layer spacing and dispersibility of attapulgite are enhanced. When treated in the modification solution, it can cooperate with the boric acid modifier solution to enhance the efficiency, jointly enhancing the water resistance and high-temperature stability performance of the product. Detailed implementation mode

[0031] The following combines specific embodiments to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] A production method of a water-resistant honeycomb activated carbon in this embodiment includes the following steps:

[0033] 1) Mixing and preparing slurry: Select activated carbon powder with a 200-mesh passing rate of more than 90% and moisture within 10% as the raw material, and an inorganic binder with a 200-mesh passing rate of more than 95% and moisture within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 5-1:1 to obtain a mixed slurry with a solid content of 15-30%.

[0034] 2) High-pressure dehydration: Feed the mixed slurry in step 1) to a dehydrator through a feed pump, with full feeding, and then completely dehydrate it by high-pressure extrusion at 10-20 MPa or by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and enters the stirring tank for slurry preparation. After dehydration, unload the material to obtain a mixed mud with a water content within 55% in the filter cake.

[0035] 3) Rough refining and forming: Convey the mixed mud in step 2) to a kneader through a belt for kneading for 30-60 minutes, and then discharge it to a belt and convey it to a cylindrical extruder for extrusion forming to obtain a roughly refined columnar mud.

[0036] 4) Refined refining and forming: Convey the roughly refined columnar mud in step 3) to a cylindrical extruder with a vacuum of -0.06 to -0.09 MPa for extrusion forming to obtain a refined columnar mud.

[0037] 5) Die forming: Convey the refined columnar mud in step 4) to an extruder equipped with a honeycomb die for extrusion forming, and then cut it automatically to obtain a honeycomb-shaped wet material.

[0038] 6) Heating and drying: Put the honeycomb-shaped wet material from step 5) into the drying room and conduct timed drying successively at three temperature ranges of 30 - 40 °C, 40 - 50 °C, and 50 - 80 °C. After drying, the water content is within 5% to obtain the honeycomb-shaped dry material;

[0039] 7) Heat treatment: Put the honeycomb-shaped dry material from step 6) into a sealed and oxygen-deficient high-temperature furnace at 500 - 600 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for heating and drying through a heat exchanger. After heat treatment for 8 - 10 h, then naturally cool to obtain honeycomb activated carbon.

[0040] In the mixed slurry of this embodiment, a boric acid modifier solution accounting for 1 - 5% of the total amount of the mixed slurry is also added.

[0041] The preparation method of the boric acid modifier solution in this embodiment is as follows:

[0042] Add boric acid to the chitosan regulating solution according to a weight ratio of 1:5, and stir evenly to obtain the boric acid modifier;

[0043] The chitosan regulating solution in this embodiment includes the following raw materials in parts by weight: 10 - 20 parts of chitosan, 30 - 40 parts of deionized water, 1 - 4 parts of lanthanum sulfate, and 2 - 5 parts of sodium alginate aqueous solution.

[0044] The mass fraction of the sodium alginate aqueous solution in this embodiment is 20 - 30%.

[0045] In step 1) of this embodiment, the particle size of the activated carbon powder is such that the passing rate of 200 meshes is above 90%, the water content is within 10%, and the iodine value is 600 - 1300 mg / g; the inorganic binder is one or more of attapulgite clay, bentonite, and sepiolite. The particle size of the inorganic clay is such that the passing rate of 200 meshes is above 95% and the water content is within 10%; the activated carbon powder and attapulgite clay are fed in a mass ratio of 3 - 1:1, and the solid content of the mixed slurry is 15 - 30%.

[0046] In step 2) of this embodiment, the water content of the filter cake after high-pressure dehydration is within 55%; in step 3), the kneading time of the kneader is 30 - 60 min;

[0047] In step 4), the vacuum degree of the vacuum pumping is -0.06 - -0.09 MPa.

[0048] In step 6) of this embodiment, for the heating and drying, dry at a temperature of 30 - 40 °C for 1 - 2 days, at a temperature of 40 - 50 °C for 1 - 2 days, and at a temperature of 50 - 80 °C for 1 day. Adjust the drying humidity and dry slowly to reduce the breakage of the honeycomb-shaped wet material. After drying, the water content is within 5%.

[0049] In step 7) of this embodiment, the heat treatment temperature is 500 - 600 °C and the heat treatment time is 8 - 10 h;

[0050] The iodine value of the honeycomb activated carbon described in step 7) can reach 800-1000 mg / g or more, and the carbon tetrachloride adsorption rate reaches 60-80%.

[0051] Example 1.

[0052] A production method of a water-resistant honeycomb activated carbon in this example includes the following steps:

[0053] 1) Mixing and preparing slurry: Select activated carbon powder with a 200-mesh passing rate of more than 90% and moisture within 10% as raw materials, and an inorganic binder with a 200-mesh passing rate of more than 95% and moisture within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 5:1 to obtain a mixed slurry with a solid content of 15%.

[0054] 2) High-pressure dehydration: Send the mixed slurry in step 1) to a dehydrator through a feed pump, with full feeding, and then completely dehydrate it by high-pressure extrusion at 10 MPa or by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and returned to the stirring tank for slurry preparation. After dehydration, unload the material to obtain a mixed mud with moisture within 55% in the filter cake.

[0055] 3) Rough refining and forming: Send the mixed mud in step 2) to a kneader through a belt for kneading for 30 minutes, and then discharge it to a belt and send it to a cylindrical extruder for extrusion forming to obtain a roughly refined columnar mud.

[0056] 4) Refined refining and forming: Send the roughly refined columnar mud in step 3) to a cylindrical extruder with a vacuum of -0.06 MPa through a belt for extrusion forming to obtain a refined columnar mud.

[0057] 5) Die forming: Send the refined columnar mud in step 4) to an extruder equipped with a honeycomb die for extrusion forming, and then cut it automatically to obtain a honeycomb-shaped wet material.

[0058] 6) Heating and drying: Put the honeycomb-shaped wet material in step 5) into a drying room and carry out timed drying in three temperature sections of 30 °C, 40 °C, and 50 °C in sequence. After drying, the moisture content is within 5% to obtain a honeycomb-shaped dry material.

[0059] 7) Heat treatment: Put the honeycomb-shaped dry material in step 6) into a sealed and oxygen-deficient high-temperature furnace at 500 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for heating and drying through a heat exchanger. After heat treatment for 8 hours, then cool it naturally to obtain honeycomb activated carbon.

[0060] A boric acid modifier solution accounting for 2% of the total amount of the mixed slurry is also added to the mixed slurry in this example.

[0061] The preparation method of the boric acid modifier solution in this example is as follows:

[0062] Adding boric acid to the chitosan adjustment solution at a weight ratio of 1:5, then adding 2% of the total amount of boric acid sodium alkyl sulfonate and 1% of hydrochloric acid, stirring evenly, to obtain a boric acid modifier;

[0063] S02: Add nano-silica to a 2-fold sodium alginate aqueous solution, then add 1% sodium oxalate and 1% silane coupling agent KH560 based on the total amount of nano-silica, stir thoroughly, then wash with water and dry to obtain pretreated nano-silica;

[0064] S03: Add the pretreated nano-silica to 4 times the boric acid modifier and stir thoroughly. After stirring, wash with water and dry to obtain a boric acid modifier solution.

[0065] The chitosan regulating solution of this embodiment includes the following raw materials in parts by weight: 10 parts of chitosan, 30 parts of deionized water, 1 part of lanthanum sulfate, and 2 parts of sodium alginate aqueous solution.

[0066] The mass fraction of the sodium alginate aqueous solution in this embodiment is 20%.

[0067] The activated carbon powder described in step 1) of this embodiment has a particle size of 200 mesh pass rate of more than 90%, a moisture content of less than 10%, and an iodine value of 600 mg / g; the inorganic binder is attapulgite, and the inorganic clay has a particle size of 200 mesh pass rate of more than 95% and a moisture content of less than 10%; the activated carbon powder and attapulgite are added in a mass ratio of 3:1, and the solid content of the mixed slurry is 15-30%.

[0068] The moisture content of the filter cake after high-pressure dehydration in step 2) of this embodiment is within 55%; the kneading time of the kneading machine in step 3) is 30 minutes;

[0069] The vacuum degree of the evacuation described in step 4) is -0.06MPa.

[0070] The heating and drying described in step 6) of this embodiment is carried out by drying at 30°C for 1 day, drying at 40°C for 1 day, and drying at 50°C for 1 day, adjusting the drying humidity and drying slowly to reduce the breakage of the honeycomb wet material, and the moisture content after drying is within 5%.

[0071] The heat treatment temperature in step 7) of this embodiment is 500° C. and the heat treatment time is 8 h;

[0072] The iodine value of the honeycomb activated carbon described in step 7) can reach more than 800 mg / g, and the carbon tetrachloride adsorption rate can reach 60%.

[0073] Example 2.

[0074] A method for producing water-resistant honeycomb activated carbon in this embodiment comprises the following steps:

[0075] 1) Mixed pulp preparation: Select activated carbon powder with a passing rate of over 90% through 200 meshes and moisture within 10% as the raw material, and inorganic binder with a passing rate of over 95% through 200 meshes and moisture within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 1:1 to obtain a mixed slurry with a solid content of 30%.

[0076] 2) High-pressure dehydration: Feed the mixed slurry in step 1) to a dehydrator through a feed pump. Ensure full feeding, and then completely dehydrate it by high-pressure extrusion at 20 MPa or by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and returned to the stirring tank for pulp preparation. After dehydration, unload the material to obtain a mixed mud with moisture within 55% in the filter cake.

[0077] 3) Rough refining and forming: Convey the mixed mud in step 2) to a kneader through a belt for kneading for 60 minutes, and then discharge it to a belt and convey it to a cylindrical extruder for extrusion forming to obtain a roughly refined columnar mud.

[0078] 4) Fine refining and forming: Convey the roughly refined columnar mud in step 3) to a cylindrical extruder under -0.09 MPa vacuum for extrusion forming to obtain a finely refined columnar mud.

[0079] 5) Die forming: Convey the finely refined columnar mud in step 4) to an extruder equipped with a honeycomb die for extrusion forming, and then perform automatic cutting to obtain a honeycomb-shaped wet material.

[0080] 6) Temperature rise and drying: Put the honeycomb-shaped wet material in step 5) into a drying room and perform timed drying in three temperature sections of 40 °C, 50 °C, and 80 °C in sequence. After drying, the moisture content is within 5% to obtain a honeycomb-shaped dry material.

[0081] 7) Heat treatment: Put the honeycomb-shaped dry material in step 6) into a sealed and oxygen-deficient high-temperature furnace at 600 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for temperature rise and drying through a heat exchanger. After heat treatment for 10 hours, then naturally cool down to obtain honeycomb activated carbon.

[0082] In the mixed slurry of this embodiment, a boric acid modifier solution accounting for 5% of the total amount of the mixed slurry is also added.

[0083] The preparation method of the boric acid modifier solution in this embodiment is as follows:

[0084] Add boric acid to the chitosan regulating solution according to a weight ratio of 1:5 to obtain a boric acid modifier.

[0085] The chitosan regulating solution in this embodiment includes the following raw materials in parts by weight: 20 parts of chitosan, 40 parts of deionized water, 4 parts of lanthanum sulfate, and 5 parts of sodium alginate aqueous solution.

[0086] The mass fraction of the sodium alginate aqueous solution in this embodiment is 30%.

[0087] In step 1) of this embodiment, the particle size of the activated carbon powder is such that the passing rate through 200-mesh sieve is over 90%, the moisture content is within 10%, and the iodine value is 1300 mg / g; the inorganic binder is attapulgite, and the particle size of the inorganic clay is such that the passing rate through 200-mesh sieve is over 95% and the moisture content is within 10%; the activated carbon powder and attapulgite are fed in a mass ratio of 1:1, and the solid content of the mixed slurry is 30%.

[0088] The pre-improved attapulgite is fed into 5 times of the modifier, stirred evenly, then washed with water and dried to obtain the modified attapulgite.

[0089] In step 2) of this embodiment, the water content of the filter cake after high-pressure dehydration is within 55%; in step 3), the kneading time of the kneader is 60 min;

[0090] In step 4), the vacuum degree of the vacuum pumping is -0.09 MPa.

[0091] In step 6) of this embodiment, for the temperature-rising drying, it is dried at 40°C for 2 days, at 50°C for 2 days, and at 80°C for 1 day in sequence. The drying humidity is adjusted to dry slowly to reduce the breakage of the honeycomb-shaped wet material, and the moisture content after drying is within 5%.

[0092] In step 7) of this embodiment, the heat treatment temperature is 600°C and the heat treatment time is 8 - 10 h;

[0093] In step 7), the iodine value of the honeycomb activated carbon can reach over 1000 mg / g, and the carbon tetrachloride adsorption rate reaches 80%.

[0094] Example 3.

[0095] A production method of a water-resistant honeycomb activated carbon in this embodiment includes the following steps:

[0096] 1) Mixing and preparing slurry: Select activated carbon powder with a passing rate through 200-mesh sieve over 90% and a moisture content within 10% as the raw material, and an inorganic binder with a passing rate through 200-mesh sieve over 95% and a moisture content within 10%. The activated carbon powder and the inorganic binder are fed into a stirring tank equipped with hot water in a mass ratio of 3:1 to obtain a mixed slurry with a solid content of 15 - 30%;

[0097] 2) High-pressure dehydration: The mixed slurry in step 1) is sent to a dehydrator through a feed pump, with full feeding, and then completely dehydrated by high-pressure extrusion at 15 MPa or completely dehydrated by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and enters the stirring tank for slurry preparation. After dehydration, it is unloaded to obtain a mixed mud material with a water content of the filter cake within 55%;

[0098] 3) Coarse refining and forming: The mixed mud material from step 2) is conveyed by a belt to a kneading machine for kneading for 45 minutes, and then discharged to a belt and conveyed to a cylindrical extruder for extrusion forming to obtain a coarsely refined columnar mud material;

[0099] 4) Fine refining and forming: The coarsely refined columnar mud material from step 3) is conveyed by a belt to a cylindrical extruder with a vacuum of -0.07 MPa for extrusion forming to obtain a finely refined columnar mud material;

[0100] 5) Die forming: The finely refined columnar mud material from step 4) is conveyed by a belt to an extruder equipped with a honeycomb die for extrusion forming, and then obtained as a honeycomb-shaped wet material through automatic cutting;

[0101] 6) Heating and drying: The honeycomb-shaped wet material from step 5) is put into a drying room and dried at three temperature sections of 35 °C, 45 °C, and 65 °C in sequence for a fixed time. After drying, the water content is within 5% to obtain a honeycomb-shaped dry material;

[0102] 7) Heat treatment: The honeycomb-shaped dry material from step 6) is put into a sealed and oxygen-deficient high-temperature furnace at 550 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for heating and drying through a heat exchanger. After heat treatment for 9 hours, it is then naturally cooled to obtain honeycomb activated carbon.

[0103] In the mixed slurry of this embodiment, a boric acid modifier solution accounting for 3.5% of the total amount of the mixed slurry is also added.

[0104] The preparation method of the boric acid modifier solution in this embodiment is as follows:

[0105] Boric acid is added to the chitosan regulating solution according to a weight ratio of 1:5 to obtain a boric acid modifier;

[0106] The chitosan regulating solution in this embodiment includes the following raw materials in parts by weight: 15 parts of chitosan, 35 parts of deionized water, 2.5 parts of lanthanum sulfate, and 3.5 parts of sodium alginate aqueous solution.

[0107] The mass fraction of the sodium alginate aqueous solution in this embodiment is 25%.

[0108] In step 1) of this embodiment, the particle size of the activated carbon powder is that the passing rate of 200 mesh is above 90%, the water content is within 10%, and the iodine value is 90 mg / g; the inorganic binder is attapulgite, and the particle size of the inorganic clay is that the passing rate of 200 mesh is above 95% and the water content is within 10%; the activated carbon powder and attapulgite are fed in a mass ratio of 3 to 1:1, and the solid content of the mixed slurry is 20%.

[0109] In step 2) of this embodiment, the water content of the filter cake after high-pressure dehydration is within 55%; in step 3), the kneading time of the kneading machine is 45 minutes;

[0110] In step 4), the vacuum degree of the vacuum extraction is -0.07 MPa.

[0111] In the step 6) of this embodiment, for the temperature-raising and drying, it is dried for 2 days at 35°C, 1.5 days at 45°C, and 1 day at 65°C in sequence. The drying humidity is adjusted to dry slowly to reduce the breakage of the honeycomb-shaped wet material, and the water content after drying is within 5%.

[0112] In the step 7) of this embodiment, the heat treatment temperature is 550°C and the heat treatment time is 9 h;

[0113] In the step 7), the iodine value of the honeycomb activated carbon can reach more than 950 mg / g, and the carbon tetrachloride adsorption rate reaches 70%.

[0114] Comparative Example 1.

[0115] It is different from Example 3 in that the boric acid modifier solution is not added.

[0116] Comparative Example 2.

[0117] It is different from Example 3 in that the chitosan regulating solution is not added in the preparation of the boric acid modifier solution.

[0118] Comparative Example 3.

[0119] It is different from Example 3 in that the boric acid modifier solution is replaced by boric acid.

[0120] Comparative Example 4.

[0121] It is different from Example 3 in that chitosan is not added to the boric acid modifier in the preparation of the boric acid modifier solution.

[0122] Comparative Example 5.

[0123] It is different from Example 3 in that lanthanum sulfate is not added in the preparation of the chitosan regulating solution.

[0124] Comparative Example 6.

[0125] It is different from Example 3 in that the aqueous sodium alginate solution is not added in the preparation of the chitosan regulating solution.

[0126] The products of Examples 1 - 3 and Comparative Examples 1 - 10 are subjected to performance tests;

[0127]

[0128]

[0129] It can be seen from Comparative Examples 1-6 and Examples 1-3 that the present invention uses a boric acid modifier solution, and the strength and adsorption properties of the product have excellent stability properties in terms of water resistance and high temperature. Without adopting one of the treatment methods, the stability of the product performance shows a significant deterioration trend. In addition, in the preparation of the boric acid modifier solution of the present invention, no chitosan regulating solution is added, the boric acid modifier solution is replaced by boric acid, and the components of the chitosan regulating solution are different, and the performance of the product shows a deterioration trend. Only the boric acid modifier solution prepared by the method of the present invention has a significant improvement effect on the performance stability of the product.

[0130] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0131] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A production method of water-resistant honeycomb activated carbon, characterized in that, it includes the following steps: 1) Mixing and preparing slurry: Select activated carbon powder with a 200-mesh passing rate of more than 90% and moisture within 10% as raw materials, and inorganic binder with a 200-mesh passing rate of more than 95% and moisture within 10%. Put the activated carbon powder and the inorganic binder into a stirring tank equipped with hot water according to a mass ratio of 5-1:1 to obtain a mixed slurry with a solid content of 15-30%. 2) High-pressure dehydration: Feed the mixed slurry in step 1) to a dehydrator through a feed pump, with full feeding, and then completely dehydrate it by high-pressure extrusion at 10-20 MPa or completely dehydrate it by air blowing with compressed air above 0.8 MPa. The filtered water is recycled and enters the stirring tank for slurry preparation. After dehydration, unload the material to obtain a mixed mud with a water content of less than 55% in the filter cake. 3) Rough refining and forming: Convey the mixed mud in step 2) to a kneader through a belt for kneading for 30-60 minutes, and then discharge it to a belt and convey it to a cylindrical extruder for extrusion forming to obtain a roughly refined columnar mud. 4) Refined refining and forming: Convey the roughly refined columnar mud in step 3) to a cylindrical extruder with a vacuum of -0.06 to -0.09 MPa through a belt for extrusion forming to obtain a refined columnar mud. 5) Die forming: Convey the refined columnar mud in step 4) to an extruder equipped with a honeycomb die for extrusion forming, and then cut it automatically to obtain a honeycomb-shaped wet material. 6) Heating and drying: Put the honeycomb-shaped wet material in step 5) into a drying room and conduct timed drying in three temperature sections of 30-40 °C, 40-50 °C, and 50-80 °C in sequence. After drying, the water content is less than 5% to obtain a honeycomb-shaped dry material. 7) Heat treatment: Put the honeycomb-shaped dry material in step 6) into a sealed and oxygen-deficient high-temperature furnace at 500-600 °C for heat treatment. The heat treatment flue gas is used to obtain hot air for heating and drying through a heat exchanger. After heat treatment for 8-10 hours, then cool down naturally to obtain honeycomb activated carbon. In the mixed slurry in step 1), a boric acid modifier solution accounting for 1-5% of the total amount of the mixed slurry is also added; In step 1), the activated carbon powder has a particle size with a 200-mesh passing rate of more than 90%, moisture within 10%, and an iodine value of 600-1300 mg / g; the inorganic binder is one or more of attapulgite clay, bentonite, and sepiolite. The inorganic clay has a 200-mesh passing rate of more than 95% and moisture within 10%; the activated carbon powder and the inorganic binder are fed according to a mass ratio of 3-1:1, and the solid content of the mixed slurry is 15-30%.

2. A production method of water-resistant honeycomb activated carbon according to claim 1, characterized in that, the preparation method of the boric acid modifier in step 2) is: Add boric acid to the chitosan regulating solution according to a weight ratio of 1:5, and stir evenly to obtain a boric acid modifier solution.

3. A production method of water-resistant honeycomb activated carbon according to claim 2, characterized in that, the chitosan regulating solution includes the following raw materials in parts by weight: 10-20 parts of chitosan, 30-40 parts of deionized water, 1-4 parts of lanthanum sulfate, and 2-5 parts of sodium alginate aqueous solution.

4. A production method of water-resistant honeycomb activated carbon according to claim 3, characterized in that, The mass fraction of the sodium alginate aqueous solution is 20-30%.

5. A production method of a water-resistant honeycomb activated carbon according to claim 1, characterized in that the water content of the filter cake after high-pressure dehydration in step 2) is within 55%; the kneading time of the kneader in step 3) is 30-60 min; the vacuum degree of the vacuum pumping in step 4) is -0.06 to -0.09 MPa.

6. A production method of a water-resistant honeycomb activated carbon according to claim 1, characterized in that for the temperature-raising drying in step 6), it is dried at a temperature of 30-40 °C for 1-2 days, dried at a temperature of 40-50 °C for 1-2 days, dried at a temperature of 50-80 °C for 1 day, the drying humidity is adjusted to slowly dry to reduce the breakage of the honeycomb wet material, and the water content after drying is within 5%.

7. A production method of a water-resistant honeycomb activated carbon according to claim 1, characterized in that the heat treatment temperature in step 7) is 500-600 °C, and the heat treatment time is 8-10 h; the iodine value of the honeycomb activated carbon in step 7) can reach 800-1000 mg / g or more, and the carbon tetrachloride adsorption rate reaches 60-80%.

Images