CN118772677A - Anti-oxidation coating for anode of aluminum electrolytic cell and preparation method thereof - Google Patents
Anti-oxidation coating for anode of aluminum electrolytic cell and preparation method thereof Download PDFInfo
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- C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
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Abstract
本发明涉及电解铝技术领域，具体涉及一种铝电解槽阳极用抗氧化涂料及其制备方法。所述铝电解槽阳极用抗氧化涂料包括：20‑70份填料、20‑40份粘结剂和20‑40份溶剂；所述填料中含有处理铝灰；所述填料中，Al2O3和SiO2的重量比为1.0‑2.0:1；所述处理铝灰的处理工艺为：将铝灰在1000‑1400℃中搅拌反应2h，冷却后即得。本发明涂层为低温准熔融阳极抗氧化涂料，在较低的温度下实现涂层中成分的熔融，一方面增加涂层和预焙阳极的黏结强度，另一方面赋予涂层自愈合性能，使得涂层能够愈合氧化过程中因受到热应力，或者热膨胀系数不匹配，或者杂质挥发引起的开裂和孔隙。The present invention relates to the technical field of electrolytic aluminum, and specifically to an anti-oxidation coating for an aluminum electrolytic cell anode and a preparation method thereof. The anti-oxidation coating for an aluminum electrolytic cell anode comprises: 20-70 parts of a filler, 20-40 parts of a binder and 20-40 parts of a solvent; the filler contains treated aluminum ash; in the filler, the weight ratio of Al2O3 to SiO2 is 1.0-2.0:1; the treatment process of the treated aluminum ash is: stirring the aluminum ash at 1000-1400°C for 2h, and cooling to obtain the result. The coating of the present invention is a low-temperature quasi-melting anode anti-oxidation coating, which realizes the melting of the components in the coating at a relatively low temperature, on the one hand, increases the bonding strength between the coating and the prebaked anode, and on the other hand, gives the coating self-healing properties, so that the coating can heal cracks and pores caused by thermal stress, mismatch of thermal expansion coefficient, or volatilization of impurities during oxidation.
Description
Technical Field
The invention relates to the technical field of electrolytic aluminum, in particular to an antioxidant coating for an anode of an aluminum electrolysis cell and a preparation method thereof.
Background
In the electrolytic production process of aluminum, the carbon anode is in a high-temperature oxidizing atmosphere at 450-950 ℃ and a fluorine-containing corrosive atmosphere, threshing, chipping and oxidizing combustion can occur, which is also a main cause of increasing the consumption of carbon materials.
The excessive consumption of the carbon anode mainly comprises secondary consumption caused by Boolean reaction, selective oxidation of anode material and mechanical loss. In the process of aluminum electrolysis production, anode gas permeates into the pores inside the anode to generate Boolean reaction, so that secondary consumption is caused; the oxidizing difference between the binder asphalt and the aggregate petroleum coke causes the falling of part of the aggregate to form carbon slag; the anode slag is removed due to the huge pressure and flow velocity impact force generated in the process of moving the anode bubbles to the edge. The carbon slag not only can shorten the service life of the anode, but also can cause voltage drop to rise, generate a hot tank and increase the electric energy consumption of aluminum electrolysis, and the labor intensity of workers can be increased when the carbon slag is fished out.
The coating method is an effective method for improving the oxidation resistance of the carbon material and the carbon material, and the main mechanism is that the high-melting-point oxidation-resistant material is sprayed on the surface of the carbon material to form a coating, so that a sintered or fused product is generated on the surface of the carbon material, and the contact path of the carbon material and air is broken. The carbon anode in the aluminum electrolysis cell starts to oxidize at the temperature of more than 500 ℃, so that a high-efficiency protective coating needs to form a compact structure at the temperature of 500 ℃ to prevent the erosion of air.
The prior art CN108315765A discloses an aluminum electrolysis anode anti-oxidation coating prepared by utilizing aluminum ash, the aluminum ash is treated by adopting an alkali dissolution-dehydration treatment process, the treated aluminum ash is used as a coating binder and a filler, and an organic aid is matched to prepare the anti-oxidation coating, but the method has low nitrogen removal efficiency, needs alkali dissolution-water immersion-cooling-filtering-dehydration and other processes, releases a large amount of ammonia gas in the treatment process, and has long process flow and poor operability.
The prior art CN 110577758B provides a method for preparing carbon anode antioxidation coating for electrolytic aluminum by comprehensively utilizing aluminum ash; the raw materials comprise aluminum ash, strong alkali, aluminum powder, boron compounds, organic auxiliary adhesives and water in parts by weight; the preparation method comprises the following steps: adding aluminum ash into water, and preserving heat under stirring; collecting generated ammonia gas, cooling liquid materials, filtering, transferring filtrate into evaporation equipment to evaporate and recover soluble chloride therein, and collecting distilled water generated in the evaporation process; adding strong alkali to obtain alkali solution; adding the filter residue and aluminum powder obtained by filtration, stirring, and partially dissolving alkali to obtain a carbon anode coating adhesive for electrolytic aluminum and a filler; and finally adding a boron compound and an organic auxiliary adhesive into the adhesive, and uniformly mixing. On the one hand, the invention uses dissolved alkali as a binder and organic matters as a bonding auxiliary agent, after the organic auxiliary binder volatilizes at high temperature, the viscosity of the coating is reduced, and the viscosity of a melt of strong alkali is very low, so that the coating can not be bonded on the surface of the carbon anode for a long time; on the other hand, the invention adopts wet treatment to the aluminum ash, and a large amount of ammonia gas with pungent smell can be generated in the treatment process, which is a great threat to the environment and the health of operators.
Disclosure of Invention
The invention aims to provide an antioxidation coating for an anode of an aluminum electrolysis cell, which can be used for prolonging the service life of an anode carbon block of the aluminum electrolysis cell.
In order to achieve the above object, the technical scheme of the present invention is as follows:
an antioxidation coating for an anode of an aluminum electrolysis cell comprises the following components in parts by weight: 20-70 parts of filler, 20-40 parts of binder and 20-40 parts of solvent;
The filler contains treated aluminum ash;
The weight ratio of Al 2O3 to SiO 2 in the filler is 1.0-2.0;
The treatment process for treating the aluminum ash comprises the following steps: stirring aluminum ash at 1000-1400 deg.c for 2 hr, and cooling to obtain the final product.
The oxidation resistance of the coating is determined by the weight ratio of Al 2O3 to SiO 2 as long as the components of the oxidation resistance coating for the anode of the aluminum electrolysis cell are Al 2O3 and SiO 2, Wherein SiO 2 determines the fluidity of the coating, siO 2 becomes a high-viscosity liquid phase at high temperature, when cracks or bubbles appear in the coating, the flowing liquid phase can heal the cracks and bubbles, the coating is ensured not to crack, and m (SiO 2) is smaller, Coating cracks are difficult to heal. Al 2O3 forms a solid phase at high temperature, which determines the toughness of the coating, m (Al 2O3) is too small, the coating can easily flow freely on the surface of the anode, and the carbon anode of the inner layer is exposed. The coating has the best protection effect when the weight ratio of Al 2O3 to SiO 2 is 1.0-2.0, and when the weight ratio of Al 2O3 to SiO 2 is more than 2, The m (Al 2O3) is too large, the fluidity of the coating is reduced, and cracks appear in the coating and are difficult to heal; When the weight ratio of Al 2O3 to SiO 2 is less than 1, m (Al 2O3) is too small, the coating fluidity is too high, and the coating flows on the surface of the anode, exposing the carbon anode matrix.
The invention adopts the high-temperature nitrogen removal process to remove nitrogen element in the aluminum ash, converts aluminum nitride into aluminum oxide, has the advantages of high nitrogen removal efficiency, short flow and good nitrogen removal effect, avoids ammonia gas in the wet treatment process, returns the treated aluminum ash as a filler to an electrolytic tank for recycling, and reduces the disposal cost of the aluminum ash.
In contrast, the alkali dissolution-dehydration treatment of aluminum ash can generate a large amount of ammonia gas, and is toxic, the alkali dissolution treatment efficiency is low, the process flow is long, and the conversion rate of aluminum in the aluminum ash into Al 2O3 is low.
In one preferred embodiment, the aluminum ash is black gray aluminum ash after metal aluminum is extracted by a parching ash method.
In one preferred embodiment, the black gray aluminum ash after extracting the metal aluminum contains 20-60 wt% of aluminum element.
The aluminum ash is white aluminum ash and black aluminum ash, the white aluminum ash contains more aluminum, manufacturers fry metal aluminum in the aluminum ash by using an ash frying method, and the rest products are the black aluminum ash, so that the treatment difficulty is high. The invention treats black aluminum ash as a raw material, and solves the problem.
In one preferred embodiment, the filler further comprises alumina and silica fume.
The addition amount of alumina, treated aluminum ash and silica fume is controlled to make the weight ratio of Al 2O3 to SiO 2 in the composition be 1.0-2.0.
In one preferred embodiment, the filler comprises 10-40 parts treated aluminum ash, 5-40 parts silica fume.
In one preferred embodiment, the treated aluminum ash comprises 70-80 parts aluminum oxide, 5-20 parts aluminum nitride, 1-5 parts aluminum fluoride, 0-1 parts calcium oxide, 0-1 parts silicon dioxide, 0-1 parts magnesium oxide, 0-1 parts potassium oxide, 0-1 part sodium oxide, and 0-1 part iron oxide.
In one preferred embodiment, the filler comprises 50 to 70 weight percent of the total amount of the coating in parts by mass.
Al 2O3 in the filler is solid at high temperature, plays a role in toughening, the filling ratio ensures the toughness of the coating in the range, and is lower than the range, m (Al 2O3) in the coating is lower, the toughness of the coating is poor at high temperature, and the coating is easy to fall off on the surface of the anode. Too high, the binder in the coating is low in content, and is easy to crack at normal temperature, meanwhile, the binder contains macromolecule chain-shaped SiO 2, the filler content is high, the m (SiO 2) content in the coating is low, and finally the viscosity of the coating is low
Meanwhile, when the filler is less than 50wt%, the coating has less high temperature and cannot cover the surface of the carbon block, the filler is more than 70wt%, the binder in the coating is too little, the coating is easy to crack at high temperature, and the coating loses the protection effect.
In one preferred embodiment, the treated aluminum ash accounts for 5 to 40 weight percent of the total coating in parts by mass.
The aluminum ash contains fluorine, a small amount of fluorine is favorable for reducing the liquid phase temperature in the coating, the volatilization temperature of carbon is about 500 ℃, and the liquid phase can be generated earlier to heal the pore space in the coating so as to protect the anode. However, when the aluminum ash content is too high, the liquid phase temperature is greatly reduced, so that the viscosity of the coating is greatly reduced under the service condition of the electrolytic tank of 960 ℃, the viscosity of the coating and the matrix is reduced, and the coating falls off from the surface of the carbon anode.
In one preferred embodiment, the binder comprises 1-5 parts quartz sand, 0.1-2 parts potassium hydroxide, and 0.1-2 parts sodium hydroxide.
In one preferred embodiment, the binder is prepared by a process comprising:
Adding quartz sand, sodium hydroxide and potassium hydroxide into an autoclave, and reacting for 1-6h at 150-2000 ℃ and 0.4-0.8 MPa and 10-50 r/min in the presence of water vapor to obtain the adhesive.
The pressure and the temperature are too small, the time is too short, the dissolved SiO 2 is less, the binder is less, the coating viscosity is low, the protective performance is poor, the temperature is too high, the pressure is too large, the time is too long, the binder is too much, the melting point of the coating is low, the fluidity is strong at high temperature, and the protective performance of the coating is reduced.
SiO 2 is solid, but can be dissolved in alkali, after the dissolution, siO 2 is connected into a polymer SiO 2 chain under the catalysis of alkali metal, and the polymer SiO 2 chain serves as a binder in the coating. In contrast, if the SiO 2 is simply mixed at normal temperature, the solubility of SiO 2 in alkali solution is very small, the coating obtained by directly mixing the alkali and SiO 2 has no viscosity, and the coating can naturally fall off when being sprayed on the surface of the anode at normal temperature.
In one preferred embodiment, the solvent is water, ethanol or methanol, preferably water.
In one preferred embodiment, the crystalline form of alumina in the filler is alpha alumina.
The alpha-type alumina is the final crystal form of the alumina, is often used as a ceramic raw material, has strong oxidation resistance, and can not cause the cracking of the coating due to the thermal stress of the crystal form transformation at high temperature. If other crystal forms of alumina are selected, crystal form transformation can occur at high temperature, and in the transformation process, the thermal expansion coefficient changes, so that the coating is subjected to thermal stress, and finally the coating is cracked.
In one preferred embodiment, the particle size D90 of the silica fume is less than or equal to 2 μm, and the particle size D90 of the aluminum ash is less than or equal to 5 μm.
The powder material has smaller particle size, can better protect the coating, and has poorer oxidation resistance when the particle size is too coarse.
The particle size of the coating influences the protection effect of the coating, the particle size is too large, gaps among coating particles are large, liquid phase is difficult to fill the gaps, and finally the substrate is oxidized by air. The particle size is too small, the surface hydroxyl groups between the alumina powder and the silicon dioxide powder are too much, the viscosity is large, the agglomeration is easy, and the spraying cannot be performed.
The invention also discloses a preparation method of the antioxidation coating for the aluminum electrolysis cell anode, which comprises the following steps:
Ball milling is carried out on the treated aluminum ash and the solvent to obtain inorganic filler; then adding solvent and binder to disperse at the rotation speed of 500-1000 rpm to prepare the antioxidant coating for the aluminum electrolysis cell anode.
An antioxidation coating for an anode of an aluminum electrolysis cell, which comprises the following preparation methods: spraying the antioxidant paint on the surface of the carbon anode, controlling the thickness to be 0.3-0.5 mm, naturally drying for 24-48h, and reacting at 800-1100 ℃ for 5-12h to obtain the aluminum electrolysis cell anode.
The coating material of the invention is only required to be sprayed on the surface of the carbon anode, the thickness is controlled to be 0.3-0.5 mm, and the coating material is naturally dried for 24-48h and then reacts for 5-12h at 800-1100 ℃, thus the coating material can be used, and the anode period of two days can be reduced and prolonged.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, the aluminum ash is treated by adopting a fire roasting mode, nitride in the aluminum ash is treated into nitrogen oxide to be discharged, so that harmless treatment of the nitride is realized, the process flow is short, the safety and environmental protection are realized, the efficiency is high, the nitrogen removal effect is good, nitrogen element volatilizes in the form of nitrogen oxide at high temperature, and the defect of ammonia gas generated in the wet treatment process of the aluminum ash can be avoided.
(2) The aluminum ash is used as an alumina source, so that the accumulation of the aluminum ash is reduced, the damage of the aluminum ash to the environment is reduced, and meanwhile, the aluminum resource in the aluminum ash is reasonably utilized, so that a new road is explored for the recycling of the aluminum ash.
(3) Aiming at the defects that the sintering temperature of the traditional coating ceramic coating is high, the surface of the coating is not compact enough, pores are reserved, air is easy to enter, and the coating is not tightly bonded with a carbon anode, the coating is a low-temperature quasi-melting anode antioxidation coating, and the melting of components in the coating is realized at a lower temperature, so that the bonding strength of the coating and a prebaked anode is improved on the one hand, and the self-healing performance of the coating is endowed on the other hand, so that the coating can heal cracks and pores caused by thermal stress, mismatch of thermal expansion coefficients or volatilization of impurities in the oxidation process.
Drawings
FIG. 1 is the oxidation results of the sample of example 1.
FIG. 2 is the result of oxidation of the sample of comparative example 1.
FIG. 3 is the result of oxidation of the sample of comparative example 2.
FIG. 4 is the result of oxidation of the sample of comparative example 3.
FIG. 5 is a low temperature oxidized micro-topography of the coating of example 1.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without any inventive effort, are intended to be within the scope of the invention.
Example 1
The specific implementation steps of the embodiment are as follows:
(1) The secondary aluminum ash in Henan certain place is selected, and the components are as follows:
TABLE 1 Secondary aluminum ash composition
| Al | Si | O | Na | F | Ca | Mg | K | Fe | N |
| 40.68％ | 2.22％ | 38.53％ | 2.72％ | 4.12％ | 2.69％ | 1.55％ | 0.54％ | 0.37％ | 7.72％ |
Adding the aluminum ash into an aluminum melting furnace at 1200 ℃ for stirring reaction for 2 hours, and cooling to obtain the denitrification aluminum ash, wherein the components are as follows:
TABLE 2 Denitrification of the Components of aluminum Ash
| Al | Si | O | Na | F | Ca | Mg | K | Fe | N |
| 43.10％ | 2.36％ | 46.11％ | 2.63％ | 4.27％ | 2.65％ | 1.54％ | 0.40％ | 0.38％ | 0.29％ |
(2) According to the mass powder, 20 parts of denitrogenated aluminum ash, 10 parts of silicon micropowder and 10 parts of water are added into a ball mill for wet grinding, so that inorganic filler is obtained, and at the moment, al 2O3：SiO2 is approximately equal to 1.5:1 in the filler.
(3) Adding 2 parts of quartz sand, 0.5 part of sodium hydroxide, 0.5 part of potassium hydroxide and 2 parts of water into an autoclave, and reacting for 2 hours at 160 ℃ under 0.6MPa and 20r/min in a steam atmosphere to obtain a liquid binder;
(4) Adding the filler and the liquid binder in the steps (3) and (4) into a high-speed dispersing machine, and dispersing for 0.5h at the speed of 800 revolutions per minute; coating 1 was obtained.
(5) And (3) adding 10 parts of silicon micropowder in the step (3) into 8 parts of silicon micropowder and 15 parts of silicon micropowder respectively, wherein at the moment, al 2O3：SiO2 in the filler is 2:1 and 1:1 respectively, and coating 2 and coating 3 are obtained respectively.
(6) The prepared paint 1-3 is sprayed on the surface of a carbon anode with the thickness of 6 multiplied by 4 multiplied by 2cm, the thickness is controlled to be 0.3-0.5 mm, the carbon anode is dried for 24 hours at normal temperature and then is placed into a muffle furnace for reaction for 10 hours at 950 ℃, the oxidized sample of the paint 1 is shown in figure 1, the oxidized sample results of the paint 2 and the paint 3 are similar to those of figure 1, and the carbon anode oxidation results are shown in table 1. Analyzing the low-temperature oxidation microscopic morphology of the coating, and the result is shown in figure 5, wherein the coating is mainly dense solid-phase particles at the low temperature of 350 ℃; at 400 ℃, the low melting point component such as silicate in the coating begins to deform, and the deformed solid particles can fill the pores among the solid particles; the low-melting-point component is close to the melting point at 450 ℃, and the solid phase particles are completely deformed; when the temperature reaches 500 ℃, the low-melting phase of the coating is completely melted into a liquid phase, and a smooth coating structure of dense crack object pores is formed. It can be seen that the coating can complete the melting process before the carbon anodic oxidation (before 500 ℃), forming a dense structure, preventing the erosion of air.
Comparative example 1
Example 1 was repeated except that 10 parts of the fine silica powder was added in step (3) of example 1 instead of 4.5 parts of the fine silica powder. At this time, al 2O3：SiO2 in the filler is approximately equal to 3:1, and other raw materials, processes and operation steps are the same as in example 1. The oxidized samples are shown in FIG. 2, and the carbon anodic oxidation results are shown in Table 1.
Comparative example 2
Example 1 was repeated except that 10 parts of the fine silica powder was added in step (3) of example 1 instead of 32 parts of silica. At this time Al 2O3：SiO2 in the filler was approximately 1:2, and the sample after oxidation was as in FIG. 3, other raw materials, process and procedure were as in example 1. The results of carbon anodic oxidation are shown in Table 1.
As can be seen from example 1 and comparative examples 1-2, when the optimal effect is that m (Al 2O3)：m(SiO2)＝1-2:1.m(Al2O3):m(SiO2) > 2:1, m (Al 2O3) is too large, the fluidity of the coating is reduced, and cracks appear in the coating and are difficult to heal; when m (Al 2O3):m(SiO2) is less than 1:1, m (Al 2O3) is too small, the coating mobility is too high, and the coating flows on the surface of the anode to expose the carbon anode matrix.
Comparative example 3
(1) According to mass powder, 20 parts of alumina, 10 parts of silica micropowder and 10 parts of water are added into a ball mill for wet grinding, so that inorganic filler is obtained, and at the moment, al 2O3：SiO2 is approximately equal to 1.5:1 in the filler.
(2) Adding 2 parts of quartz sand, 0.5 part of sodium hydroxide, 0.5 part of potassium hydroxide and 2 parts of water into an autoclave, and reacting for 2 hours at 160 ℃ under 0.6MPa and 20r/min in a steam atmosphere to obtain a liquid binder;
(3) Adding the filler and the liquid binder in the steps (1) and (2) into a high-speed dispersing machine, and dispersing for 0.5h at the speed of 800 revolutions per minute; the coating is obtained.
(4) The prepared coating is sprayed on the surface of a carbon anode with the thickness of 6 multiplied by 4 multiplied by 2cm, dried for 24 hours at normal temperature, placed into a muffle furnace for reaction for 10 hours at 950 ℃, the oxidized sample is shown in figure 4, and the carbon anode oxidation result is shown in table 1.
The embodiment shows that the nitrogen content in the aluminum ash can be effectively reduced after the aluminum ash is subjected to high-temperature treatment. By comparative examples 1 and 3, the coating layer using aluminum ash after nitrogen removal as a filler was consistent with the coating layer protecting effect of pure alumina as a filler, and thus it was possible to produce a carbon anode oxidation-resistant coating layer using aluminum ash as a filler.
Example 2
The specific implementation steps of the embodiment are as follows:
(1) The secondary aluminum ash in Henan certain place is selected, and the components are as follows:
TABLE 3 Secondary aluminum ash composition
| Al | Si | O | Na | F | Ca | Mg | K | Fe | N |
| 40.68％ | 2.22％ | 38.53％ | 2.72％ | 4.12％ | 2.69％ | 1.55％ | 0.54％ | 0.37％ | 7.72％ |
Adding the aluminum ash into an aluminum melting furnace at 1200 ℃ for stirring reaction for 2 hours, and cooling to obtain the denitrification aluminum ash, wherein the components are as follows:
TABLE 4 Denitrification of the Components of aluminum Ash
| Al | Si | O | Na | F | Ca | Mg | K | Fe | N |
| 43.10％ | 2.36％ | 46.11％ | 2.63％ | 4.27％ | 2.65％ | 1.54％ | 0.40％ | 0.38％ | 0.29％ |
(2) According to the mass parts, adding 20 parts of denitrogenated aluminum ash, 10 parts of silicon micropowder and 10 parts of water into a ball mill for wet grinding to obtain inorganic filler, wherein Al 2O3：SiO2 is approximately equal to 1.5:1 in the filler.
(3) Adding 2 parts of quartz sand, 0.5 part of sodium hydroxide, 0.5 part of potassium hydroxide and 2 parts of water into an autoclave, and reacting for 2 hours at 180 ℃ under the steam atmosphere at 0.8MPa for 20 revolutions per minute to obtain a liquid binder;
(4) Adding the filler and the liquid binder in the steps (2) and (3) into a high-speed dispersing machine, and dispersing for 0.5h at the speed of 800 revolutions per minute; the coating is obtained.
(5) The prepared coating is sprayed on the surface of a carbon anode with the thickness of 6 multiplied by 4 multiplied by 2cm, dried for 24 hours at normal temperature, then placed into a muffle furnace for reaction for 10 hours at 950 ℃, and the carbon anode oxidation result is shown in table 1.
Comparative example 4
Example 2 was repeated except that the reaction was carried out at 160℃under 0.6MPa at 20 rpm in the steam atmosphere for 2 hours at 140℃under 0.4MPa at 20 rpm in step (4) of example 1, and the reaction was carried out at 2 hours in the steam atmosphere with other raw materials, processes and operation steps as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 5
Example 2 was repeated except that the reaction was changed to be carried out at 160℃under 0.6MPa at 20 rpm in the steam atmosphere in step (4) of example 1 for 2 hours at 200℃under 0.9MPa at 20 rpm in the steam atmosphere, and the other raw materials, processes and operation steps were the same as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 6
Example 2 was repeated except that step (1) of example 1 was omitted, and 20 parts of secondary aluminum ash from a place in Henan, 10 parts of fine silica powder, and 10 parts of water were directly added to a ball mill to perform wet milling, thereby obtaining an inorganic filler. Other materials, processes and operating procedures were as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 7
Example 2 was repeated except that step (3) of example 1 was omitted, and 2 parts of quartz sand, 0.5 part of sodium hydroxide, 0.5 part of potassium hydroxide, 2 parts of water and the filler of step (2) were directly mixed and dispersed. Other materials, processes and operating procedures were as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 8
Example 2 was repeated except that the steps (1) and (2) of example 1 were omitted, 20 parts of secondary aluminum ash in Henan province, 10 parts of fine silica powder and 10 parts of water were directly added into a ball mill to perform wet milling to obtain an inorganic filler, and then the inorganic filler was directly mixed with 2 parts of quartz sand, 0.5 part of sodium hydroxide, 0.5 part of potassium hydroxide and 2 parts of water and then dispersed. Other materials, processes and operating procedures were as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 9
Example 2 was repeated except that the procedure (1) of example 1 was modified to alkali-dehydrate the secondary aluminum ash of Henan, and then wet-milled with 10 parts of fine silica powder and 10 parts of water in a ball mill to obtain an inorganic filler. The alkali dissolution-dehydration treatment comprises the following steps: weighing 40 parts of secondary aluminum ash in a certain place in Henan, and analyzing the aluminum and aluminum oxide content in the aluminum ash; the aluminum ash is added into an open container, and enough water is added for hydrolyzing aluminum nitride, and ammonia gas in the hydrolysis process is collected. Carrying out filter pressing treatment on the salt solution, and delivering the filtrate to recycle salt as a raw material for preparing an aluminum liquid refining agent for later use; adding enough alkali liquor into the filter residue according to the aluminum and aluminum oxide contents in the aluminum ash to fully dissolve the aluminum and aluminum oxide in the residue; and (3) carrying out filter pressing treatment on the alkali solution, conveying ferric oxide and silicon oxide filter residues to a storage yard for storage, evaporating filtrate to dryness to prepare sodium metaaluminate, adding 20 parts of sodium metaaluminate dry matters and 10 parts of silicon micropowder into a ball mill, and carrying out wet grinding on 10 parts of water.
Other materials, processes and operating procedures were as in example 2. The results of carbon anodic oxidation are shown in Table 1.
Comparative example 10
Example 2 was repeated except that 20 parts of denitrogenated aluminum ash was added in the step (2) of example 1, 10 parts of silica fume was changed to 10 parts of denitrogenated aluminum ash, 5 parts of silica fume, and other raw materials, and the process and operation steps were the same as those of example 2, and the carbon anodic oxidation results are shown in Table 1
Comparative example 11
Example 2 was repeated except that 20 parts of denitrogenated aluminum ash was added in step (2) of example 1, 10 parts of silica fume was changed to 60 parts of denitrogenated aluminum ash, 30 parts of silica fume, and other raw materials, and the process and operation steps were the same as those of example 2, and the carbon anodic oxidation results are shown in table 5.
TABLE 5 graphite oxidation results obtained for the different examples and comparative examples
| Examples | Graphite mass/g | Mass/g of dried coating | Post oxidation mass/g | Loss of quality |
| Example 1 | 82.12 | 85.88 | 79.66 | 7.24wt％ |
| Comparative example 1 | 84.26 | 88.05 | 74.05 | 15.89wt％ |
| Comparative example 2 | 82.43 | 86.12 | 71.57 | 16.89wt％ |
| Comparative example 3 | 82.15 | 86.45 | 80.18 | 7.25wt％ |
| Example 2 | 84.33 | 90.52 | 84.08 | 7.11wt％ |
| Comparative example 4 | 83.12 | 89.74 | 81.89 | 8.54wt％ |
| Comparative example 5 | 83.45 | 88.97 | 80.77 | 9.21wt％ |
| Comparative example 6 | 82.43 | 86.39 | 72.38 | 16.22wt％ |
| Comparative example 7 | 81.56 | 85.99 | 72.89 | 15.23wt％ |
| Comparative example 8 | 81.74 | 86.58 | 71.43 | 17.49wt％ |
| Comparative example 9 | 80.26 | 85.63 | 85.60 | 19.89wt％ |
| Comparative example 10 | 79.85 | 84.88 | 78.36 | 7.68wt％ |
| Comparative example 11 | 80.41 | 85.23 | 78.13 | 8.33wt％ |
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.
Claims (10)
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5164003A (en) * | 1990-03-28 | 1992-11-17 | Ceram Tech International, Ltd. | Room temperature curable surface coating and methods of producing and applying same |
| JP2006283083A (en) * | 2005-03-31 | 2006-10-19 | Kobe Steel Ltd | Aluminum ash, desulfurizing agent for steelmaking, and method for producing aluminum ash |
| CN108315765A (en) * | 2018-04-22 | 2018-07-24 | 新疆大学 | It is a kind of to prepare aluminium electrolysis anode antioxidizing paint using aluminium lime-ash |
| CN110577758A (en) * | 2019-09-17 | 2019-12-17 | 江西省科学院应用化学研究所 | A method for comprehensive utilization of aluminum ash to prepare carbon anode anti-oxidation coating for electrolytic aluminum |
| CN116103509A (en) * | 2022-08-30 | 2023-05-12 | 佛山市井昌环境科技有限公司 | A kind of resource utilization method of aluminum ash |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5164003A (en) * | 1990-03-28 | 1992-11-17 | Ceram Tech International, Ltd. | Room temperature curable surface coating and methods of producing and applying same |
| JP2006283083A (en) * | 2005-03-31 | 2006-10-19 | Kobe Steel Ltd | Aluminum ash, desulfurizing agent for steelmaking, and method for producing aluminum ash |
| CN108315765A (en) * | 2018-04-22 | 2018-07-24 | 新疆大学 | It is a kind of to prepare aluminium electrolysis anode antioxidizing paint using aluminium lime-ash |
| CN110577758A (en) * | 2019-09-17 | 2019-12-17 | 江西省科学院应用化学研究所 | A method for comprehensive utilization of aluminum ash to prepare carbon anode anti-oxidation coating for electrolytic aluminum |
| CN116103509A (en) * | 2022-08-30 | 2023-05-12 | 佛山市井昌环境科技有限公司 | A kind of resource utilization method of aluminum ash |
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