CN111662578A - Preparation process of spherical chromium oxide composite agglomerated powder and product prepared by preparation process - Google Patents
Preparation process of spherical chromium oxide composite agglomerated powder and product prepared by preparation process Download PDFInfo
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Abstract
The invention discloses a preparation process of spherical chromium oxide composite agglomerated powder and a product prepared by the preparation process, belonging to the technical field of composite powder materials, wherein the preparation process comprises the following steps: dissolving chromium nitrate in deionized water, adding SiO2Nanopowder and TiO2Adding ammonia water dropwise to the nanometer powder to adjust the pH value of the solution to obtain SiO2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying; preparing a solid product into slurry by using deionized water, preparing spherical agglomerated powder by combining a spray granulation and atmosphere protection sintering process, and then carrying out particle size classification on the spherical agglomerated powder to obtain spherical chromium oxide composite agglomerated powder; the chromium oxide composite agglomerated powder with uniform chemical components and better sphericity, compactness, fluidity and the like can be prepared by adopting the preparation process.
Description
Technical Field
The invention relates to the technical field of composite powder materials, in particular to a preparation process of spherical chromium oxide composite agglomerated powder and a product prepared by the preparation process.
Background
The chromium oxide composite powder material formed by adding a proper amount of silicon oxide and titanium oxide into the chromium oxide powder can improve the heating melting property of the chromium oxide powder in the spraying process, improve the spraying process performance of the chromium oxide powder, improve the powder deposition efficiency and the binding force with a matrix, and is beneficial to improving the fracture toughness and the post-processing performance of a chromium oxide coating. The chromium oxide composite powder material also has the characteristics of low friction coefficient, high heat conductivity coefficient and high hardness, and also has good chemical stability and excellent corrosion resistance, so the chromium oxide composite powder material can be used as a thermal spraying wear-resistant coating in wear-resistant areas such as ceramic anilox rollers, printer cylinders, pump seal rings, moving and static rings, wear-resistant blades and the like and an anti-corrosion coating on metal surfaces such as steel and the like, and is very widely applied.
At present, the method for preparing the chromium oxide composite powder for thermal spraying is mainly a melting and crushing process, and the method generally comprises the following steps: directly mixing three kinds of nano-powder of chromium oxide, silicon oxide and titanium oxide together, and then preparing composite powder by a spray drying technology. However, the chromium oxide powder prepared by the process has uneven distribution of chemical components, and when the chromium oxide powder is used for spraying, the obtained chromium oxide coating has a local segregation phenomenon, so that the comprehensive performance of the chromium oxide coating is influenced. Therefore, there is a need to develop a new method for preparing a chromium oxide composite powder for thermal spraying, which can produce a chromium oxide composite powder with a uniform chemical composition.
Disclosure of Invention
Aiming at the defects in the prior art, the first purpose of the invention is to provide a preparation process of spherical chromium oxide composite agglomerated powder, and the spherical chromium oxide composite agglomerated powder with better uniformity can be prepared by adopting the preparation process.
The second purpose of the invention is to provide a spherical chromium oxide composite agglomerated powder which has the advantages of good uniformity, sphericity, compactness and fluidity.
In order to achieve the first object, the invention provides the following technical scheme:
a preparation process of spherical chromium oxide composite agglomerated powder comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO2Nanopowder and TiO2Performing ultrasonic treatment on the nano powder to obtain a mixed solution; dropwise adding ammonia water into the mixed solution, and adjusting the pH value of the solution to 8-11 to obtain SiO2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying;
(2) preparing slurry with solid content of 50-60% by using a solid product, a binder and deionized water, wherein the binder accounts for 3-15% of the weight of the solid product, and preparing spherical agglomerated powder by using a spray granulation and atmosphere protection sintering process;
(3) and carrying out particle size classification on the spherical agglomerated powder according to the use requirement to obtain the required spherical chromium oxide composite agglomerated powder. By adopting the technical scheme, in the invention, SiO is firstly added2Nanopowder and TiO2Adding the nano powder into chromium nitrate solution and carrying out ultrasonic treatment on the chromium nitrate solution, wherein SiO is obtained2Nanopowder and TiO2The nanometer powder can be uniformly dispersed in the chromium nitrate solution, so that the uniform dispersivity of each component of the powder particles is improved; then ammonia water is dripped in the mixture,can be obtained as SiO2Nanopowder and TiO2The nanometer powder is a coated precursor of the inner core, and in the process, ammonia water is used as a precipitator to better precipitate chromium hydroxide and SiO2Nanopowder and TiO2Crystal nuclei formed by the nano powder are precipitated together, so that the uniformity of each component is maintained; finally, spray granulation and granularity grading are carried out to obtain the spherical chromium oxide composite agglomerated powder which consists of chromium oxide, silicon oxide and titanium oxide and has uniform chemical components.
In the invention, SiO with the granularity of 5-20 nm is preferably selected2Nanopowder and TiO2Nanopowder, conveniently SiO2Nanopowder and TiO2The nanometer powder is uniformly dispersed in the chromium nitrate solution to reduce SiO2Nanopowder and TiO2The probability of agglomeration of the nano powder in the chromium nitrate solution is favorable for improving the uniformity of a finished product.
In the invention, when the spherical chromium oxide composite agglomerated powder is used in a thermal spraying process, the particle size of the spherical chromium oxide composite agglomerated powder is generally 270-500 meshes.
Further, in the step (1), the dropping speed of the ammonia water is 3.0-10.0 ml/min, and the mixed solution is continuously stirred at a stirring speed of 200-400 r/min in the dropping process.
By adopting the technical scheme, the chromium nitrate can be dissolved in the deionized water to form a chromium nitrate solution, and the SiO2Nanopowder and TiO2The nanometer powder can not be dissolved in the chromium nitrate solution, and when ammonia water is dripped, the dripping speed is too high, so that the nanometer powder is agglomerated, and the dispersion effect is influenced; if the dripping speed is too slow, the coating effect of the precursor is affected, so that the uniformity of the chemical components of the product is ensured by the specific dripping speed. When the ammonia water is dripped, the precipitate can be orderly separated out by dripping and stirring at a specific speed, and the agglomeration of the nano powder is reduced, so that the uniformity of a finished product can be improved.
Further, in the step (1), before ammonia water is dripped into the mixed solution, a dispersing agent accounting for 0.1-5% of the total weight of the solid raw materials is added, and the mixture is stirred at a stirring speed of 200-400 r/min for 0.5-1 h; still further, the dispersant is selected from any one of polyethylene glycol, lauryl ether or polyacrylic acid.
By adopting the technical scheme, the dispersing agent accounts for 0.1-5% of the total weight of the solid raw material, wherein the total weight of the solid raw material refers to chromium nitrate and SiO2Nanopowder and TiO2The total weight of the nanometer powder. SiO 22Nanopowder and TiO2The nanometer powder is not miscible with water, and the dispersant can prevent SiO2Nanopowder and TiO2The nano powder is settled, agglomerated or condensed in the chromium nitrate solution, thereby better dissolving SiO2Nanopowder and TiO2The nanometer powder is uniformly dispersed in the chromium nitrate solution, so that the uniformity of the final finished product is improved.
Further, in the step (1), the frequency during ultrasonic treatment is 20-120 KHz.
By adopting the technical scheme, the solution is subjected to ultrasonic treatment according to specific ultrasonic frequency, so that SiO can be effectively prevented2Nanopowder and TiO2The nano powder is agglomerated in the chromium nitrate solution, thereby achieving the effect of full dispersion.
Further, in the step (1), after the chromium nitrate is dissolved in deionized water, the concentration is 1-3 mol/L; the SiO2Nanopowder, TiO2The mass ratio of the nano powder to the chromium nitrate is (3-5): (2-4): (285-297.5).
By adopting the technical scheme, the chromium nitrate and the SiO are added according to a specific proportion2Nanopowder and TiO2The nanometer powder is convenient for obtaining the spherical chromium oxide composite agglomerated powder with uniform chemical components and better performance.
Further, the binder is selected from any one of polystyrene, polyvinyl alcohol and dextrin.
By adopting the technical scheme, the addition of the binder is beneficial to the bonding of each powder substance in the slurry and the molding of the chromium oxide composite agglomerated powder; the selection of the specific dosage and type of the binder is beneficial to improving the strength of the aggregate and the mechanical properties of compactness and the like of the product.
Further, it is characterized in that: the technological parameters of spray granulation in the step (2) comprise: the rotating speed of the spray head is 35 to 45r/s, the feeding speed is 50 to 60r/min, the inlet temperature is 250 to 300 ℃,
by adopting the technical scheme, the spray granulation is a granulation method that the powder slurry or the solution is sprayed into a granulation tower, and the powder slurry or the solution is dried and agglomerated under the action of spray hot air, so that spherical granules are obtained. In the invention, during spray granulation, the solid content of the slurry is strictly controlled, a specific binder is added into the slurry, the rotating speed of a spray head of a granulation tower, the feeding speed, the inlet temperature and the like are controlled, all process parameters are mutually influenced, and the sphericity of the agglomerated powder can be improved, so that the agglomerated powder with good sphericity can be prepared. The method is carried out according to specific spray granulation parameters, and particularly, the rotating speed of a spray head is controlled, so that the yield of the 270-500-mesh spherical chromium oxide composite agglomerated powder can be improved.
Further, in the atmosphere protection sintering process, the oxygen partial pressure in the sintering atmosphere is controlled to be 10-5～10- 6atm, sintering temperature of 1200-1300 ℃, and heat preservation time of 3-5 h.
By adopting the technical scheme, the atmosphere protection sintering process can prevent other gases from influencing the agglomerated particles, and measures such as strict control of sintering temperature and heat preservation time are adopted, so that the agglomerated powder with better compactness can be obtained. In the present invention, when the oxygen partial pressure is controlled, the controlled atmosphere may be selected from any one of argon, nitrogen and helium, and further, the controlled atmosphere is preferably nitrogen. By controlling the oxygen partial pressure in the sintering atmosphere, the valence state of the chromium can be prevented from changing, and the purity of the finished product can be ensured and improved. In the invention, ammonia water is selected as a precipitator, and sintering is carried out under a protective atmosphere (namely oxygen partial pressure is controlled) in the granulation and sintering process, so that the influence of impurities on a finished product can be reduced, and the agglomerated powder with good purity and good compactness can be obtained.
In the invention, the agglomerated powder is prepared by adopting a spray granulation and atmosphere protection sintering process, and the strictly limited range of each process parameter is favorable for preparing the agglomerated powder with better sphericity and compactness, and the prepared agglomerated powder has better fluidity under the condition of better sphericity and compactness.
In the present invention, in the step (3), when the spherical agglomerated powder is subjected to particle size classification, the particle size classification method may be a sieving method or an air classification method. When a screening method is selected for classification, screens of 270 meshes and 500 meshes are adopted, the screen of 270 meshes is placed right above the screen of 500 meshes, the prepared agglomerated powder passes through the two screens in sequence, and finally, the agglomerated powder which can pass through the screen of 270 meshes but can not pass through the screen of 500 meshes is selected, so that the final finished product, namely the spherical chromium oxide composite agglomerated powder, can be prepared.
In order to achieve the second object, the invention provides the following technical scheme:
the spherical chromium oxide composite agglomerated powder comprises a product prepared by the preparation process of the spherical chromium oxide composite agglomerated powder.
The spherical chromium oxide composite agglomerated powder obtained by the preparation method provided by the invention has the advantages of uniform chemical components, good purity, good sphericity and good compactness, and also has excellent fluidity.
In conclusion, the invention has the following beneficial effects:
firstly, because the invention adopts the chemical precipitation method to firstly prepare SiO2Nanopowder and TiO2Dissolving the nano powder in chromium nitrate solution, and then preparing SiO by taking ammonia water as a precipitator2And TiO2The nano powder is a coated precursor of the kernel, so that the uniform dispersivity of all components in the powder particles is improved, and the chromium oxide composite agglomerated powder with better chemical component uniformity can be finally prepared;
second, in the present invention, by changing SiO2Nanopowder and TiO2Sequence of addition of nanopowderUltrasonic treatment is matched, the dropping speed of precipitator ammonia water, the stirring environment and the like are controlled, and the steps are matched with each other to prepare chromium oxide composite agglomerated powder with better chemical uniformity;
thirdly, in the granulation process, the sintering is carried out under the condition of controlling the atmosphere, the oxygen partial pressure is controlled, the valence state change of chromium in the sintering process can be effectively inhibited, and the agglomerated powder with high purity and better compactness can be prepared;
fourthly, the agglomerated powder with better sphericity can be prepared by controlling the technological parameters of spray granulation, such as solid content of slurry, rotating speed of a spray head and the like;
fifthly, when the precursor with better dispersibility is obtained, the sphericity and compactness of the agglomerated powder can be ensured by adopting a granulation technology combining spray granulation and atmosphere sintering processes, so that the chromium oxide composite agglomerated powder with excellent flowing property can be prepared.
Drawings
FIG. 1 is an electron microscope scanning image of the spherical chromium oxide composite agglomerated powder obtained in example 1.
FIG. 2 is an electron microscope scanning image of the spherical chromium oxide composite agglomerated powder obtained in example 6.
FIG. 3 is an electron microscope scanning image of the spherical chromium oxide composite agglomerated powder obtained in example 15.
Fig. 4 is an energy spectrum for measuring the uniformity of each chemical component of the spherical chromium oxide composite agglomerated powder obtained in example 19, wherein fig. 4-1 shows the uniformity of Cr in the spherical chromium oxide composite agglomerated powder, fig. 4-2 shows the uniformity of Si in the spherical chromium oxide composite agglomerated powder, and fig. 4-3 shows the uniformity of Ti in the spherical chromium oxide composite agglomerated powder.
Fig. 5 is a spectrum diagram for measuring the uniformity of each chemical component of the spherical chromium oxide composite agglomerated powder prepared in comparative example 1, wherein fig. 5-1 shows the uniformity of Cr in the spherical chromium oxide composite agglomerated powder, fig. 5-2 shows the uniformity of Si in the spherical chromium oxide composite agglomerated powder, and fig. 5-3 shows the uniformity of Ti in the spherical chromium oxide composite agglomerated powder.
Detailed Description
Example 1
A preparation process of spherical chromium oxide composite agglomerated powder comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO into the solution2Nanopowder and TiO2Nanopowder (wherein, the concentration of the chromium nitrate solution is 2mol/L, SiO)2、TiO2And chromium nitrate in a mass ratio of 4.5: 3: 289.7), carrying out ultrasonic treatment to obtain a mixed solution; dropwise adding ammonia water into the mixed solution, and adjusting the pH value of the solution to 9 to obtain SiO2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying;
(2) preparing the solid product prepared in the step (1) and polystyrene accounting for 15% of the weight of the solid product into slurry with the solid content of 55% by using deionized water, spraying the prepared slurry into a granulation tower, and preparing spherical agglomerated powder by combining spray granulation and an atmosphere protection sintering process; the technological parameters in the spray granulation process are controlled as follows: the rotating speed of the spray head is 35r/s, the feeding rate is 50r/min, and the inlet temperature is 300 ℃; the technological parameters in the atmosphere protection sintering process are controlled as follows: the atmosphere was controlled with nitrogen, and the partial pressure of oxygen in the sintering atmosphere was controlled to 10-5atm, sintering temperature of 1200 ℃, and heat preservation time of 3 h; (3) and (3) sequentially passing the spherical agglomerated powder obtained in the step (2) through 270-mesh and 500-mesh sieves, and selecting the agglomerated powder which can pass through the 270-mesh sieve but can not pass through the 500-mesh sieve, so that the spherical chromium oxide composite agglomerated powder can be obtained.
Example 2
Example 2 differs from example 1 in that: in example 2, the concentration of the chromium nitrate solution was 1mol/L, SiO2、TiO2And chromium nitrate in a mass ratio of 3: 4: 285, adding ammonia water dropwise, adjusting the pH value to 8, wherein the solid content of the slurry is 50%, and the rest is consistent with that of the example 1.
Example 3
Example 3 differs from example 1 in that: in example 3, the concentration of the chromium nitrate solution was 3mol/L, SiO2、TiO2And of chromium nitrateThe mass ratio is 5: 2: 297.5, the pH was adjusted to 11 after dropwise addition of aqueous ammonia, the solids content of the slurry was 60%, the remainder being identical to that of example 1.
Example 4
A preparation process of spherical chromium oxide composite agglomerated powder comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO into the solution2Nanopowder and TiO2Nanopowder (wherein, the concentration of the chromium nitrate solution is 2mol/L, SiO)2、TiO2And chromium nitrate in a mass ratio of 4.5: 3: 289.7), carrying out ultrasonic treatment to obtain a mixed solution; dropwise adding ammonia water into the mixed solution, wherein the dropwise adding speed of the ammonia water is 3.0ml/min, continuously stirring the mixed solution at the stirring speed of 200r/min in the dropwise adding process, and adjusting the pH value of the solution to 9 to obtain SiO2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying;
(2) preparing the solid product prepared in the step (1) and polystyrene accounting for 15% of the weight of the solid product into slurry with the solid content of 55% by using deionized water, spraying the prepared slurry into a granulation tower, and preparing spherical agglomerated powder by combining spray granulation and an atmosphere protection sintering process; the technological parameters in the spray granulation process are controlled as follows: the rotating speed of the spray head is 35r/s, the feeding rate is 50r/min, and the inlet temperature is 300 ℃; the technological parameters in the atmosphere protection sintering process are controlled as follows: the atmosphere was controlled with nitrogen, and the partial pressure of oxygen in the sintering atmosphere was controlled to 10-5atm, sintering temperature of 1200 ℃, and heat preservation time of 3 h;
(3) and (3) sequentially passing the spherical agglomerated powder obtained in the step (2) through 270-mesh and 500-mesh sieves, and selecting the agglomerated powder which can pass through the 270-mesh sieve but can not pass through the 500-mesh sieve, so that the spherical chromium oxide composite agglomerated powder can be obtained.
Example 5
Example 5 differs from example 3 in that: in example 5, the dropping rate of aqueous ammonia was 10.0ml/min, and the mixed solution was continuously stirred at a stirring rate of 200r/min during the dropping, the rest being in accordance with example 1.
Example 6
Example 6 differs from example 3 in that: in example 6, the dropping rate of aqueous ammonia was 6ml/min, and the mixed solution was continuously stirred at a stirring rate of 200r/min during the dropping, and the rest was kept the same as in example 1.
Example 7
Example 7 differs from example 6 in that: in example 7, the dropping rate of aqueous ammonia was 6ml/min, and the mixed solution was continuously stirred at a stirring rate of 400r/min during the dropping, and the rest was the same as in example 1.
Example 8
A preparation process of spherical chromium oxide composite agglomerated powder comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO into the solution2Nanopowder and TiO2Nanopowder (wherein, the concentration of the chromium nitrate solution is 2mol/L, SiO)2、TiO2And chromium nitrate in a mass ratio of 4.5: 3: 289.7), carrying out ultrasonic treatment to obtain a mixed solution; firstly adding polyethylene glycol accounting for 0.1 percent of the total weight of the solid raw materials into the mixed solution, stirring for 0.5h at the stirring speed of 200r/min, then dropwise adding ammonia water, wherein the dropping speed of the ammonia water is 3.0ml/min, continuously stirring the mixed solution at the stirring speed of 200r/min in the dropping process, adjusting the pH value of the solution to 9, and preparing the SiO solid2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying;
(2) preparing the solid product prepared in the step (1) and polystyrene accounting for 15% of the weight of the solid product into slurry with the solid content of 55% by using deionized water, spraying the prepared slurry into a granulation tower, and preparing spherical agglomerated powder by combining spray granulation and an atmosphere protection sintering process; the technological parameters in the spray granulation process are controlled as follows: the rotating speed of the spray head is 35r/s, the feeding rate is 50r/min, and the inlet temperature is 300 ℃; the technological parameters in the atmosphere protection sintering process are controlled as follows: the atmosphere is controlled by nitrogen, and the oxygen partial pressure in the sintering atmosphereControl is 10-5atm, sintering temperature of 1200 ℃, and heat preservation time of 3 h;
(3) and (3) sequentially passing the spherical agglomerated powder obtained in the step (2) through 270-mesh and 500-mesh sieves, and selecting the agglomerated powder which can pass through the 270-mesh sieve but can not pass through the 500-mesh sieve, so that the spherical chromium oxide composite agglomerated powder can be obtained.
Example 9
Example 9 differs from example 8 in that: in example 9, the polyethylene glycol accounted for 3% of the total weight of the solid starting material and stirred at a stirring rate of 300r/min for 0.8h, the remainder being identical to example 8.
Example 10
Example 10 differs from example 8 in that: in example 10, the polyethylene glycol accounted for 5% of the total weight of the solid starting material and stirred at a stirring rate of 400r/min for 1h, the remainder being identical to example 8.
Example 11
Example 11 differs from example 8 in that: in example 11, lauryl ether was used as the dispersant, and the remainder was the same as in example 8.
Example 112
Example 12 differs from example 9 in that: in example 12, the frequency of sonication was 20KHz, and the rest was the same as in example 9.
Example 13
Example 13 differs from example 9 in that: in example 13, the frequency of sonication was 120KHz, and the rest was the same as in example 9.
Example 14
Example 14 differs from example 9 in that: in example 14, the frequency of sonication was 80KHz, and the rest was the same as in example 9.
Example 15
A preparation process of spherical chromium oxide composite agglomerated powder comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO into the solution2Nanopowder and TiO2Nanopowder (wherein the concentration of the chromium nitrate solution is2mol/L，SiO2、TiO2And chromium nitrate in a mass ratio of 4.5: 3: 289.7), performing ultrasonic treatment with the ultrasonic frequency of 80KHz to obtain a mixed solution; firstly adding polyethylene glycol accounting for 0.1 percent of the total weight of the solid raw materials into the mixed solution, stirring for 0.5h at the stirring speed of 200r/min, then dropwise adding ammonia water, wherein the dropping speed of the ammonia water is 3.0ml/min, continuously stirring the mixed solution at the stirring speed of 200r/min in the dropping process, adjusting the pH value of the solution to 9, and preparing the SiO solid2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying; (2) preparing the solid product prepared in the step (1) and polystyrene accounting for 3% of the weight of the solid product into slurry with the solid content of 55% by using deionized water; spraying the prepared slurry into a granulation tower, and preparing spherical agglomerated powder by combining spray granulation with an atmosphere protection sintering process; the technological parameters in the spray granulation process are controlled as follows: the rotating speed of the spray head is 35r/s, the feeding rate is 50r/min, and the inlet temperature is 300 ℃; the technological parameters in the atmosphere protection sintering process are controlled as follows: the atmosphere was controlled with nitrogen, and the partial pressure of oxygen in the sintering atmosphere was controlled to 10-5atm, sintering temperature of 1200 ℃, and heat preservation time of 3 h; (3) and (3) sequentially passing the spherical agglomerated powder obtained in the step (2) through 270-mesh and 500-mesh sieves, and selecting the agglomerated powder which can pass through the 270-mesh sieve but can not pass through the 500-mesh sieve, so that the spherical chromium oxide composite agglomerated powder can be obtained.
Example 16
Example 16 differs from example 15 in that: in example 16, in the step (2) of preparing the slurry, polystyrene accounts for 9% of the weight of the solid product; the rest of the process was the same as in example 15.
Example 17
Example 17 differs from example 15 in that: in example 17, in the step (2), when preparing the slurry, dextrin was added to the slurry in an amount of 15% by weight based on the weight of the solid product; the rest of the process was the same as in example 15.
Example 18
Example 18 differs from example 16 in that: in example 18, the process parameters in the spray granulation process were controlled as follows: the rotational speed of the spray head was 40r/s, the feed rate was 60r/min, the inlet temperature was 250 ℃ and the rest was in accordance with example 16.
Example 19
Example 19 differs from example 16 in that: in example 19, the process parameters in the spray granulation process were controlled as follows: the rotational speed of the spray head was 45r/s, the feed rate was 55r/min, the inlet temperature was 270 ℃ and the rest was in accordance with example 116.
Example 20
Example 20 differs from example 16 in that: in example 20, the process parameters in the spray granulation process were controlled as follows: the atmosphere was controlled with nitrogen, and the partial pressure of oxygen in the sintering atmosphere was controlled to 10-6atm, sintering temperature 1300 ℃, and holding time 5h, the rest are all consistent with the example 16.
Example 21
Example 21 differs from example 16 in that: in example 21, argon was used as the controlled atmosphere, and the rest was the same as in example 16.
Comparative example 1
Comparative example 1 differs from example 6 in that: in comparative example 1, there was no continuous stirring step during the dropwise addition of aqueous ammonia, and the rest was the same as in example 6.
Comparative example 2
Comparative example 2 differs from example 6 in that: in comparative example 2, the dropping rate of aqueous ammonia was 13ml/min, and the rest was the same as in example 6.
Comparative example 3
The difference between the comparative example 3 and the example 21 is that in the comparative example 3, in the step (1), three kinds of nano-powders of chromium oxide, silicon oxide and titanium oxide are directly mixed together and uniformly mixed to obtain a solid product, and the rest is consistent with the example 21.
Comparative example 4
Comparative example 4 is different from example 21 in that in comparative example 4, polystyrene was added to the slurry in an amount of 20% by weight of the solid product when the slurry was prepared in step (2); the rest of the process was the same as in example 21.
Performance test
The sphericity, apparent density and flow property of the spherical chromium oxide composite agglomerated powder obtained in examples 1 to 21 and comparative examples 1 to 4 were measured according to the national standard GB/T21649.1 "analytical analysis of particle size images", the national standard GB/T1479.1-2011 "measurement of bulk density of metal powder" and the national standard GB/T1482-2010 "measurement of fluidity of metal powder", respectively, and the measurement results are shown in table 1.
TABLE 1 table for testing the properties of spherical chromium oxide composite powder
As can be seen from table 1, in the precipitation process, too fast ammonia water dropping speed will cause powder agglomeration, which affects the uniformity of the powder components of the finished product, and too slow dropping speed will affect the coating effect of the precursor; in the process of spray granulation, in a certain range, along with the increase of the content of the binder, the viscosity coefficient of slurry is increased, so that the atomization angle is reduced, fog drops are easy to adhere to each other after drying and granulation, so that the granules become irregular, and the powder flowability is poor.
As can be seen from the observation of FIGS. 1 to 3, the spherical chromium oxide composite agglomerated powder produced by the production method of the present invention has good sphericity.
As can be seen from FIGS. 4-1, 4-2 and 4-3, the spherical chromium oxide composite agglomerated powder prepared by the preparation method of the present invention has good chemical uniformity and substantially no segregation of the components.
As is clear from the observation of FIGS. 5-1, 5-2 and 5-3, the spherical chromium oxide composite agglomerated powder produced in comparative example 1 had poor uniformity of each chemical component and was significantly biased.
The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.
Claims (10)
1. A preparation process of spherical chromium oxide composite agglomerated powder is characterized by comprising the following steps: the method comprises the following steps:
(1) dissolving chromium nitrate in deionized water, and then adding SiO2Nanopowder and TiO2Performing ultrasonic treatment on the nano powder to obtain a mixed solution; dropwise adding ammonia water into the mixed solution, and adjusting the pH value of the solution to 8-11 to obtain SiO2Nanopowder and TiO2The nano powder is used as a coating precursor of the inner core, and a solid product is obtained after filtering and drying;
(2) preparing slurry with solid content of 50-60% by using a solid product, a binder and deionized water, wherein the binder accounts for 3-15% of the weight of the solid product, and preparing spherical agglomerated powder by using a spray granulation and atmosphere protection sintering process;
(3) and carrying out particle size classification on the spherical agglomerated powder according to the use requirement to obtain the required spherical chromium oxide composite agglomerated powder.
2. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 1, wherein: in the step (1), the dropping speed of the ammonia water is 3.0-10.0 ml/min, and the mixed solution is continuously stirred at a stirring speed of 200-400 r/min in the dropping process.
3. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 1, wherein: in the step (1), before ammonia water is dripped into the mixed solution, a dispersing agent accounting for 0.1-5% of the total weight of the solid raw materials is added, and the mixture is stirred at a stirring speed of 200-400 r/min for 0.5-1 h.
4. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 3, wherein: the dispersing agent is selected from any one of polyethylene glycol, lauryl ether or polyacrylic acid.
5. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 1, wherein: in the step (1), the frequency during ultrasonic treatment is 20-120 KHz.
6. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 1, wherein: in the step (1), after the chromium nitrate is dissolved in deionized water, the concentration is 1-3 mol/L; the SiO2Nanopowder, TiO2The mass ratio of the nano powder to the chromium nitrate is (3-5): (2-4): (285-297.5).
7. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 1, wherein: the binder is selected from any one of polystyrene, polyvinyl alcohol and dextrin.
8. The process for preparing a spherical chromium oxide composite agglomerated powder according to any one of claims 1 to 8, wherein: the technological parameters of spray granulation in the step (2) comprise: the rotating speed of the spray head is 35-45 r/s, the feeding speed is 50-60 r/min, and the inlet temperature is 250-300 ℃.
9. The process for preparing a spherical chromium oxide composite agglomerated powder according to claim 8, wherein: in the atmosphere protection sintering process, the oxygen partial pressure in the sintering atmosphere is controlled to be 10-5～10-6atm, sintering temperature of 1200-1300 ℃, and heat preservation time of 3-5 h.
10. The spherical chromium oxide composite agglomerated powder is characterized in that: the spherical chromium oxide composite agglomerated powder is prepared by the preparation process of the spherical chromium oxide composite agglomerated powder as claimed in any one of claims 1 to 9.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040173922A1 (en) * | 2003-03-04 | 2004-09-09 | Barnes Michael W. | Method for preparing pyrotechnics oxidized by basic metal nitrate |
| CN101838136A (en) * | 2010-05-14 | 2010-09-22 | 上海大豪纳米材料喷涂有限公司 | Preparation method of aluminium oxide and titanium dioxide compound ceramic powder |
| CN102145913A (en) * | 2011-04-21 | 2011-08-10 | 北京矿冶研究总院 | Preparation method of nano spherical yttrium oxide powder for thermal spraying |
| CN103086700A (en) * | 2013-02-26 | 2013-05-08 | 江苏立达高科特种材料有限公司 | Preparation method of nano oxide ceramic hollow sphere used for thermal spraying |
| CN105801105A (en) * | 2016-03-11 | 2016-07-27 | 广东风华高新科技股份有限公司 | Method for preparing deoxidized oxide pelleting powder |
-
2020
- 2020-04-27 CN CN202010346536.4A patent/CN111662578B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040173922A1 (en) * | 2003-03-04 | 2004-09-09 | Barnes Michael W. | Method for preparing pyrotechnics oxidized by basic metal nitrate |
| CN101838136A (en) * | 2010-05-14 | 2010-09-22 | 上海大豪纳米材料喷涂有限公司 | Preparation method of aluminium oxide and titanium dioxide compound ceramic powder |
| CN102145913A (en) * | 2011-04-21 | 2011-08-10 | 北京矿冶研究总院 | Preparation method of nano spherical yttrium oxide powder for thermal spraying |
| CN103086700A (en) * | 2013-02-26 | 2013-05-08 | 江苏立达高科特种材料有限公司 | Preparation method of nano oxide ceramic hollow sphere used for thermal spraying |
| CN105801105A (en) * | 2016-03-11 | 2016-07-27 | 广东风华高新科技股份有限公司 | Method for preparing deoxidized oxide pelleting powder |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112375402A (en) * | 2020-11-27 | 2021-02-19 | 安徽盈锐优材科技有限公司 | Preparation method of novel thermal spraying chromium oxide powder |
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