CN109621843B - Gradient functionalized diamond synthetic column and preparation method thereof - Google Patents
Gradient functionalized diamond synthetic column and preparation method thereof Download PDFInfo
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- CN109621843B CN109621843B CN201910066606.8A CN201910066606A CN109621843B CN 109621843 B CN109621843 B CN 109621843B CN 201910066606 A CN201910066606 A CN 201910066606A CN 109621843 B CN109621843 B CN 109621843B
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Abstract
The invention discloses a gradient functionalized diamond synthetic column and a preparation method thereof. The synthetic column is formed by horizontally superposing three graphite powder and metal catalyst powder mixed block layers, the diameters of the three block layers are equal, the height of the middle mixed block layer is greater than that of the upper and lower mixed block layers, and the mass ratio of graphite to catalyst powder in the middle mixed block layer is 0.5-1.0 times that of the two mixed block layers at the two ends. According to the method, the graphite powder and the catalyst powder are uniformly mixed by the special mixing device, so that the phenomenon of segregation of the mixed material is eliminated, and the influence of the segregation of the mixed material on the quality of the synthetic diamond is avoided. The synthesis column obviously reduces the temperature difference and the pressure difference in the diamond synthesis cavity through the control of different block layer heights and the quality of graphite and catalyst powder in the synthesis column, and avoids the phenomenon of poor diamond quality caused by large temperature difference and low internal temperature in the diamond synthesis process. The synthetic column is simple to prepare and easy to operate, and has obvious effect on reducing the temperature difference between the inside and the outside of the synthetic column in diamond synthesis.
Description
Technical Field
The invention belongs to the technical field of diamond preparation, and particularly relates to a gradient functionalized diamond synthetic column and a preparation method thereof.
Background
The synthesis of artificial diamond is a process of pressing a mixture of graphite powder and metal catalyst powder into a synthetic column, growing carbon atoms in molten liquid catalyst powder under the conditions of high temperature and high pressure suitable for the growth of diamond, and then converting graphite into diamond. In the process of synthesizing diamond, the synthesis quality and yield of diamond are influenced by the technological parameters such as temperature, pressure, synthesis time and the like, and also depend on the preparation quality of the synthetic column to a great extent, in particular the mixing uniformity between graphite powder and metal catalyst powder, and the control precision of the compression weight and size of the synthetic column body. In the preparation process of the synthetic column, the graphite powder and the metal catalyst powder in the synthetic column are required to be uniformly mixed to ensure that the graphite powder and the metal catalyst powder are fully mixed and contacted, so that diamond nucleation cores which are in sufficient quantity and uniformly distributed are formed in a synthetic cavity in the synthetic process of the diamond, and sufficient carbon sources are provided for the growth of the diamond nuclei to ensure the synthetic yield and quality of the diamond converted from the graphite powder.
As can be seen from the above-mentioned description,the mixing uniformity between the graphite powder and the metal catalyst powder in the synthetic column is a necessary condition for ensuring the synthetic quality and yield of the diamond. However, in the synthesis process, since the specific gravity difference between the graphite powder and the metal catalyst powder is large (the specific gravity of the graphite powder is 2.25 g/cm)3，Fe70Ni30The specific gravity of the catalyst powder is 8.15g/cm3) In the mixing process, the respective agglomeration phenomenon of materials with different specific gravities is easy to occur, so that the segregation of mixed materials is caused, the synthesis quality of the diamond is greatly reduced, and the synthesis yield of the diamond is also reduced. Meanwhile, the graphite powder and the metal catalyst powder have large differences in particle morphology and surface characteristics, the graphite has small friction coefficient and good lubricity, so that the mutual 'meshing' capability between the graphite powder and the metal catalyst powder particles is poor, the synthesis yield is obviously reduced, and the material segregation and aggregation are more easily caused.
In actual production, in order to mix the materials uniformly, graphite powder, metal catalyst powder and adhesive in a certain particle size and weight ratio are mixed and stirred in a three-dimensional mixer at room temperature for more than 8 hours, and the mixing uniformity is increased by prolonging the mixing time. However, in the process, although the mixing time is long, because the specific gravity difference between the graphite and the metal catalyst is large, the whole mixing process always has the tendency that heavy metal sinks and light graphite floats, and the segregation phenomenon of materials still occurs, so that the synthesis quality and yield of the diamond have large fluctuation. Therefore, how to mix materials well and prevent the phenomena of segregation, agglomeration and the like becomes a technical problem to be solved in the diamond synthesis process.
In addition, all adopt the indirect heating method in the synthetic process of diamond, namely after the heating member through synthesizing outside around the post produces heat, transfer heat to synthesizing cavity inside from synthesizing cavity edge, under this condition, have the deviation in synthesizing the cavity all the time: the outer edge region has high temperature, the middle region has low temperature (the axial temperature difference can reach 80 ℃), and the quality of the diamond synthesized in the middle region is poor (the number of connected polycrystalline is large, the number of internal impurities is large, the transparency is poor, the strength is low, particularly, the difference between TI and TTI is large and is more than 10%, and the requirement of high-quality diamond cannot be met). The synthesis columns adopted in the industry at present are synthesis columns with fixed distribution ratio of graphite and metal catalyst powder, and the components and the performance of the synthesis columns are integrated, the synthesis columns cannot adjust the internal temperature difference of the synthesis cavity through the self change of the columns, the yield of a single synthesis column is usually 250-270 carats, and the yield is low.
The heating mode of heat transfer from the outer edge to the inner edge is almost unavoidable to avoid the temperature difference phenomenon in the diamond synthesis process, and various measures are adopted in the industry for continuously improving the temperature difference so as to further improve the synthesis quality and the single block yield of the diamond. The application document with the publication number of CN207221875U describes "an artificial diamond synthesis assembly block structure", in which double groups of conductive plugs, heating elements, etc. are adopted to increase the internal temperature of the synthesis cavity by increasing the heat source conditions outside the synthesis column, reduce the temperature difference, and improve the synthesis quality and yield of the diamond, but the technical means has a complex assembly structure and a large assembly difficulty, has little effect on improving the temperature difference of the synthesis column integrated in the cavity, is not beneficial to industrial scale production, and still cannot effectively improve the temperature difference problem of the synthesis cavity. The application document with the publication number of CN106270484A describes a method for preparing a graphite core column for artificial diamond synthesis, which presets a cementite in a synthesis column, takes the cementite as a nucleation core, and adjusts the nucleation number of diamond by controlling the addition ratio of the cementite to regulate and control the synthesis granularity and quality of diamond, but the method is more suitable for the synthesis of coarse-particle diamond and can not improve the temperature difference problem of synthesis. The application document CN108144554A discloses a "manufacturing process of a novel diamond synthesis column", in which a metal catalyst is mixed with graphite powder in a certain mass ratio in a mass-d-0.1 form and pressed into about 10 pieces (each piece has a thickness of 2-5 mm), and then the pressed pieces are layered and assembled in a manner that the weight of the catalyst is sequentially reduced from top to bottom, so as to improve the problem of uneven distribution of the upper and lower end catalysts caused by the sinking of the molten catalyst in the synthesis process by adjusting the content of the upper and lower end catalyst powder in the synthesis column. However, each sheet layer manufactured by the technology is very thin, the pressed forming strength is low, the sheet layer is easy to break, and the sheet layer with a large diameter specification is difficult to press, so that the technology is difficult to be used for manufacturing a synthetic column with a large diameter (such as phi 55 mm); the catalyst is tabletted in a mode of an arithmetic progression d-0.1, the maximum weight difference of the catalysts of single sheets at the upper end and the lower end of a synthesis column is about 1g, and the effect of adjusting the temperature difference in the long-time synthesis process due to the small catalyst mass difference is weaker; meanwhile, the production efficiency is greatly reduced in the multilayer assembly process, the multiple thin sheets are assembled, the efficiency is low, the assembly precision deviation is large, the application in actual production is greatly limited, and the requirement of large-scale production is difficult to meet. Therefore, how to adopt simple measures to improve the temperature difference in the synthesis cavity and improve the synthesis quality and yield of the diamond is still a real problem which needs to be solved urgently in industrial large-scale production of the artificial diamond.
Disclosure of Invention
The invention aims at the technical problems that: in the prior art, the mixing efficiency of graphite powder and metal catalyst powder is low and uneven, segregation phenomenon is easy to occur, and the quality and yield of diamond preparation are seriously influenced. Meanwhile, in the existing diamond preparation process, the edge and the inside of the diamond synthesis column are heated unevenly due to the heating mode, deviation exists in the synthesis cavity all the time, the quality of the diamond synthesized in the middle area is deteriorated, and the reduction of the temperature difference in the synthesis cavity becomes a difficult problem in the prior art due to the indirect heating method in the diamond synthesis process.
Aiming at the problems, the invention provides a diamond synthesis column, which is divided into different block layers, and the temperature difference between the center and the edge of a cavity is changed through the difference of the use amount of raw materials at the edge and in the diamond synthesis column. The operation is simple, convenient and quick, the internal and external temperature deviation of the cavity is efficiently reduced, and the quality of the synthetic diamond is obviously changed in practical application.
The invention also provides a mixing device of the graphite powder and the metal catalyst powder in the diamond synthesis process, and the device can uniformly mix the graphite powder and the metal catalyst powder for preparing the diamond synthetic column. In the device, the material that the proportion differs great falls after the friction force between all can all be through feed bin inner wall and material with feed bin bottom material commentaries on classics to a take the altitude, and the cycle is reciprocal in the tilting rotary disk blender, and from this, the material that the proportion is big has been eliminated in pivoted feed bin to sink the segregation phenomenon, can effectively misce bene between the material.
The invention also provides a preparation method of the diamond synthetic column.
The invention relates to a gradient functionalized diamond synthetic column which is realized by the following technical scheme, and the synthetic column comprises a first mixed layer block of graphite and catalyst powder, a second mixed layer block of graphite and catalyst powder which is arranged on the first mixed layer block in parallel, and a third mixed layer block of graphite and catalyst powder which is arranged on the second mixed layer block in parallel; the diameters of the first mixed layer block, the second mixed layer block and the third mixed layer block are equal.
The gradient functionalized diamond synthesis column is characterized in that the heights of the graphite and catalyst powder first mixed layer block and the graphite and catalyst powder third mixed layer block are equal and lower than the heights of the graphite and catalyst powder second mixed layer block.
The height of the second mixed layer block of graphite and catalyst powder is 2.2 to 2.5 times of that of the first mixed layer block of graphite and catalyst powder,
preferably, the height of the graphite and catalyst powder second mixed layer block is 2.4 times of that of the graphite and catalyst powder first mixed layer block.
In the gradient functionalized diamond synthesis column, the mass ratio of graphite to catalyst powder in the first mixed layer block of graphite and catalyst powder and the mass ratio of graphite to catalyst powder in the third mixed layer block of graphite and catalyst powder are the same; the mass ratio of the graphite to the catalyst powder in the second mixed layer block of the graphite and the catalyst powder is 0.5-1.0 times of the mass ratio of the graphite to the catalyst powder in the first mixed layer block of the graphite and the catalyst powder.
The gradient functionalized diamond synthesis column is characterized in that the mass ratio of graphite to catalyst powder in the graphite to catalyst powder first mixed layer block and the graphite to catalyst powder third mixed layer block is 62-70: 30-38 parts of; the mass ratio of graphite to catalyst powder in the graphite and catalyst powder second mixed layer block is 60-55: 40-45.
In the gradient functionalized diamond synthesis column, the graphite is high-purity graphite powder (the purity is more than or equal to 99.99 percent), and the particle size of the graphite powder is 300 meshes;
the catalyst powder comprises the following raw materials in parts by weight: fe68.15%, Ni 30%, Co1.5%, Mn0.3% and La0.05%; the particle size was 400 mesh.
A material mixing device for preparing the gradient functionalized diamond synthetic column comprises an electric control device, a case, a motor arranged in the case and a hopper supporting rod arranged at the upper end outside the case, wherein one end of the hopper supporting rod is connected with the case, and the end part of the other end of the hopper supporting rod is provided with a first hopper fixing hole for placing a hopper;
the device also comprises a mixing bin connected with the motor through a shaft, and the mixing bin is driven by the motor to rotate; a feed inlet is formed in the wall of the mixing bin, and when the mixing bin is in a feeding state, the feed inlet is positioned right below a discharge outlet of the hopper;
the electric control device is connected with the motor.
Preparation gradient functionalized's compounding device for synthetic post of diamond, the hopper bracing piece include the first hopper bracing piece of vertical setting and the second hopper bracing piece that the level set up, the one end tip and the quick-witted case of first hopper bracing piece can be dismantled and be connected, the other end tip of first hopper bracing piece is articulated with the one end tip of second hopper bracing piece, the second hopper bracing piece is rotatory from top to bottom for first hopper bracing piece, the other end tip of second hopper bracing piece is provided with the first hopper fixed orifices that is used for placing the hopper.
The material mixing device for preparing the gradient functionalized diamond synthetic column is characterized in that a corresponding sealing cover is also arranged on a feed inlet of the material mixing bin; and a central hole is also formed in the wall of the mixing bin and positioned at the central rotating shaft, and a corresponding hole cover is also arranged in the central hole.
The mixing device for preparing the gradient functionalized diamond synthetic column is characterized in that a shaft sleeve is further arranged on the periphery of the shaft; the disc blender is also provided with a glass cover outside, and the glass cover is provided with a through hole for passing through the lower part of the hopper.
The mixing device for preparing the gradient functionalized diamond synthetic column is characterized in that the mixing bin is an oval mixing bin, the length of the long axis of the oval mixing bin is 800-1000 mm, and the length of the short axis of the oval mixing bin is 220-250 mm; the elliptical mixing bin rotates for mixing materials by taking the short shaft as a central rotating shaft, and the included angle between the long shaft and the vertical direction is 15-20 degrees; the wall body of the mixing bin is a 304 stainless steel plate with the thickness of 1.5-2.0 mm.
A preparation method of the diamond synthetic column with the gradient functionalization comprises the steps of mixing materials, granulating, reducing and cold press molding; the method comprises the following specific steps:
(1) preparing a first mixed layer block of graphite and catalyst powder and a third mixed layer block of graphite and catalyst powder:
a. adding required raw materials of graphite powder, catalyst powder and ethylene glycol into a mixing device for mixing;
b. b, granulating the mixed material obtained in the step a to obtain raw material particles;
c. c, reducing the raw material particles obtained in the step b to obtain reduced particles;
d. c, performing cold press molding on the reduced particles obtained in the step c to obtain a first mixed layer block of graphite and catalyst powder;
e. repeating the steps a, b, c and d to prepare a third mixed layer block of graphite and catalyst powder;
(2) preparing a second mixed layer block of graphite and catalyst powder:
preparing a second mixed layer block of graphite and catalyst powder according to the step in the step (1);
(3) and (3) stacking the graphite and catalyst powder first mixed layer block, the graphite and catalyst powder second mixed layer block and the graphite and catalyst powder third mixed layer block prepared in the steps (1) and (2) in parallel from bottom to top to obtain the gradient functionalized diamond synthetic column.
The preparation method of the gradient functionalized diamond synthetic column comprises the following steps that in the step a, the mass ratio of graphite powder, catalyst powder and glycol is 62-70: 30-38: 0.12; in the preparation process of the second mixed layer block of graphite and catalyst powder in the step (2), the mass ratio of the graphite powder, the metal catalyst powder and the ethylene glycol is as follows: 60-55: 40-45: 0.12.
the preparation method of the gradient functionalized diamond synthesis column comprises the following steps: putting the prepared graphite powder into a mixing device, adding ethylene glycol, mixing uniformly, stopping the machine, adding catalyst powder, starting the machine, and mixing uniformly to obtain a uniform mixture.
According to the preparation method of the gradient functionalized diamond synthetic column, the material mixing time of graphite powder and ethylene glycol in a material mixing device is 15-25 min, and the material mixing time after the catalyst powder is added is 20-30 min; during material mixing, the power of the motor is 15-20 kW, and the rotating speed of the motor is 0-50 rpm.
In the preparation method of the gradient functionalized diamond synthetic column, the granulation in the step b is carried out in a pair-roller granulator, the working rotating speed of the granulator is 42 revolutions per minute, and the particle size of raw material particles obtained after the granulation is finished is 2 mm.
In the preparation method of the gradient functionalized diamond synthetic column, the reduction treatment in the step c is carried out in a hydrogen reduction furnace, the temperature of the raw material particles during reduction is 1000-1100 ℃, and the reduction time is 6-8 hours.
And d, performing cold press molding in an automatic hydraulic press to perform press molding treatment, wherein the working pressure of the automatic hydraulic press is 40 Mpa.
Compared with the prior art, the invention has the following positive beneficial effects
Under the current technological conditions, the essential conditions for stabilizing and improving the synthesis quality of diamond are to ensure the mixing uniformity of graphite and catalyst powder in the synthesis column and to maintain the stability of temperature difference and pressure difference of the synthesis cavity. According to the invention, the graphite powder and the metal catalyst powder are mixed by adopting the disc mixer, the disc mixer with a certain gradient is adopted, the graphite powder and the adhesive are fully mixed at first, then the graphite powder with the adhesive and the metal catalyst powder are fully mixed, and in the mixing process, the mixed material falls under the action of gravity after reaching a certain height under the rotation of the inclined disc and is fully mixed; simultaneously, the device has effectively avoided graphite powder and metal catalyst powder to lead to because the specific gravity difference is great segregation phenomenon, can effectively avoid current three-dimensional blendor to have the phenomenon of material segregation all the time, eliminates basically because of synthesizing the stubborn disease of the tradition that the post material segregation leads to the synthetic quality of diamond, is showing the synthetic quality that promotes the diamond, has fine application prospect.
In the existing indirect heating method diamond synthesis process, the factors which have the greatest influence on the diamond synthesis quality are the temperature difference and the pressure difference of a synthesis cavity and are influenced by a synthesis assembly structure and the radiation of a top hammer, and the quality and the yield of the synthesized diamond are seriously influenced because the outer edge and the inner part of a synthesis column of the indirect heating method have larger temperature difference. According to the invention, under the condition that raw materials are fully mixed, the diamond synthetic column is divided into three layers, wherein the proportion of graphite powder in the upper layer block and the lower layer block is higher than that of the middle layer block, so that on one hand, the heat input quantity provided by an external heating source can be increased, and on the other hand, the direct heat productivity of graphite can be increased, thus the heat input quantity from two ends of the synthetic column to the middle area is effectively increased, the temperature of the central area of the synthetic column is increased, the axial temperature difference of the synthetic column is improved, and the technical problem of poor diamond quality caused by large temperature difference and low internal temperature in the diamond synthetic process is effectively avoided. The synthetic column is simple to prepare and easy to operate, and has obvious effect on reducing the temperature difference between the inside and the outside of the synthetic column in the diamond synthesis process.
The actual synthesis result shows that the quality of the diamond synthesized by the synthetic column is obviously improved, and further proves that the diamond synthetic column has the outstanding effect of reducing the temperature difference.
Drawings
FIG. 1 shows one of the schematic diagrams of a mixing apparatus for producing a gradient functionalized diamond synthesis column;
FIG. 2 shows a second schematic diagram of a material mixing apparatus for preparing a gradient functionalized diamond synthesis column;
FIG. 3 shows a third schematic diagram of a material mixing device for preparing a gradient functionalized diamond synthesis column;
FIG. 4 shows a schematic view of a hopper support bar of a mixing apparatus for producing a gradient functionalized diamond synthesis column;
FIG. 5 shows a schematic diagram of a gradient functionalized diamond synthesis column;
the symbols in the drawings indicate that: 1 represents a first mixed layer block of graphite and catalyst powder, 2 represents a second mixed layer block of graphite and catalyst powder, and 3 represents a third mixed layer block of graphite and catalyst powder;
100 denotes an electric control device, 200 denotes a cabinet, 300 denotes a motor, 400 denotes a hopper support rod, 401 denotes a first hopper fixing hole, 402 denotes a first hopper support rod, 403 denotes a second hopper support rod, 500 denotes a hopper, 600 denotes a silo, 601 denotes a feed port of the silo, 602 denotes a seal cover corresponding to the feed port, 603 denotes a center hole of the silo, 604 denotes a hole cover corresponding to the center hole, 700 denotes a shaft connecting the motor and the silo, 701 denotes a boss, 800 denotes a glass cover, and 801 denotes a through hole in the glass cover.
Detailed Description
The present invention will be described in more detail with reference to the following embodiments, but the present invention is not limited to the embodiments.
The diamond catalyst powder used in the following examples was prepared by the method described in the patent application entitled "ultrafine iron-based catalyst powder for synthesizing high self-sharpening diamond, preparation method and application thereof". The diamond catalyst powder described in the following examples was prepared from the following raw materials, by weight, fe 68.15%, Ni 30%, co 1.5%, mn 0.3%, and la 0.05%, by means of a water-gas combined atomization apparatus, and the particle size of the obtained diamond catalyst powder was 400 mesh.
The double-roller granulator is produced by Zhengzhou Yangyuan machinery limited, the full-automatic hydraulic machine is produced by Changzhou Bao pressing machinery manufacturing limited, and the ethylene glycol is analytically pure.
Example 1
A kind of diamond synthetic column of the gradient functionalization, as shown in figure 5, this synthetic column includes graphite and first mixed layer block 1 of catalyst powder, graphite and second mixed layer block 2 of catalyst powder that the parallel arrangement is on the first mixed layer block, and graphite and third mixed layer block 3 of catalyst powder that the parallel arrangement is on the second mixed layer block; the height of the first mixed layer block 1 is equal to that of the third mixed layer block 3, and the height of the first mixed layer block 1 and the height of the third mixed layer block 3 are all lower than that of the second mixed layer block 2, and the diameters of the first mixed layer block 1, the second mixed layer block 2 and the third mixed layer block 3 are equal.
Furthermore, the height of the graphite and catalyst powder second mixed layer block 2 is 2.2-2.5 times of that of the graphite and catalyst powder first mixed layer block 1.
The invention also provides another embodiment, the height of the graphite and catalyst powder second mixed layer block 2 is 2.4 times of that of the graphite and catalyst powder first mixed layer block 1;
preferably, the height of the first mixed layer block and the height of the third mixed layer block are both 10 +/-0.1 mm, and the height of the second mixed layer block is 24 +/-0.1 mm.
The invention also provides another embodiment, and the diameters of the first mixed layer block 1, the second mixed layer block 2 and the third mixed layer block 3 are all 55 +/-0.1 mm.
The invention also provides another embodiment, the mass ratio of the graphite to the catalyst powder in the first mixed layer block 1 of the graphite and the catalyst powder and the third mixed layer block 3 of the graphite and the catalyst powder is the same; the mass ratio of the graphite to the catalyst powder in the graphite and catalyst powder second mixed layer block 2 is 0.5-1.0 times of the mass ratio of the graphite to the catalyst powder in the graphite and catalyst powder first mixed layer block 1.
The invention also provides another preferred embodiment, the mass ratio of the graphite powder to the metal catalyst powder in the first mixed layer block 1 and the third mixed layer block 3 is 65-70: 35-30 parts of; the mass ratio of the graphite powder to the metal catalyst powder in the second mixed layer block is 60-55: 40-45;
preferably, the mass ratio of the graphite powder to the metal catalyst powder in the first mixed layer block 1 and the third mixed layer block 3 is 65: 35, the mass ratio of the graphite powder to the metal catalyst powder in the second mixed layer block is 60: 40.
the invention also provides another preferred embodiment, the graphite powder is high-purity graphite powder, the purity of the graphite powder is more than or equal to 99.99 percent, and the average grain diameter of the graphite powder is 300 meshes; the metal catalyst powder is prepared from the following raw materials in parts by weight: fe68.15%, Ni 30%, Co1.5%, Mn0.3% and La0.05%, and is prepared by adopting a water-gas atomization combined device; the particle size is 400 meshes.
Example 2
The embodiment provides a mixing device for preparing the gradient functionalized diamond synthetic column, as shown in fig. 1, 3 and 4, the mixing device comprises an electric control device 100, a case 200, a motor 300 arranged in the case and a hopper supporting rod 400 arranged at the upper end outside the case, wherein one end of the hopper supporting rod 400 is connected with the case 200, and the end part of the other end is provided with a first hopper fixing hole 401 for placing a hopper 500;
the device also comprises a mixing bin 600 connected with the motor 300 through a shaft 700 (a shaft sleeve 701 is arranged on the periphery of the shaft), and the mixing bin 600 is driven by the motor to rotate; a feed inlet 601 is arranged on the wall of the mixing bin 600, when the device is in a feeding state, the feed inlet 601 is positioned right below a discharge port of the material port 500, and the feed inlet 601 is provided with a corresponding sealing cover 602; a central hole 603 is further formed in the wall of the mixing bin and located at the central rotating shaft, and a corresponding hole cover 604 is arranged in the central hole 603. After the feeding of the feeding port is carried out through the feeding of the hopper, the sealing cover is added, the mixing bin rotates, the materials in the mixing bin reach the upper part from the bottom along with the rotation of the mixer, then fall into the bottom from the upper part, are fully mixed, and the mixed materials are discharged from the feeding port after the mixing is finished. The central hole arranged on the wall of the mixing bin is used for fully discharging the materials in the mixing cavity and cleaning the mixing cavity;
the mixing bin 600 is an oval mixing bin, the length of the long axis of the oval mixing bin is 800-1000 mm, and the length of the short axis of the oval mixing bin is 220-250 mm; the elliptical mixing bin uses a short shaft as a central rotating shaft, and the included angle between the long shaft and the vertical direction is 15-20 degrees.
Further, the hopper supporting rods 400 comprise a first hopper supporting rod 402 arranged vertically and a second hopper supporting rod 403 arranged horizontally; one end of the first hopper supporting rod 402 is detachably connected with the upper end of the outer portion of the case, the other end of the first hopper supporting rod 402 is hinged to one end of the second supporting rod 403, the second hopper supporting rod 403 rotates up and down relative to the first hopper supporting rod 402, and the other end of the second supporting rod 403 is provided with a first hopper fixing hole for placing a hopper.
Furthermore, the wall body of the mixing bin is a 304 stainless steel plate with the thickness of 1.5-2.0 mm.
Further, as shown in fig. 2, a glass cover 800 is arranged outside the mixer of the device, and the glass cover 800 is provided with a through hole 801 for passing through the lower part of the hopper. This glass cover further avoids at reinforced in-process and compounding in-process, and the influence that harm that has avoided causing the staff and cause the environment to operational environment is to the influence of raw materials dust, and can realize the recovery of raw materials to a certain extent and recycle.
Therefore, the mixing device can realize the mixing of the raw materials in a short time, and can uniformly mix the raw materials, thereby effectively avoiding the segregation phenomenon. Short time, high efficiency and good material mixing effect.
Example 3
A preparation method of the gradient functionalized diamond synthesis column comprises the following steps:
(1) preparing graphite powder, metal catalyst powder and ethylene glycol;
(2) preparation of first mixed layer block of graphite and catalyst powder
a. Preparing raw materials: 13Kg of high-purity graphite powder, 120g of ethylene glycol and 7Kg of metal catalyst powder prepared in the step (1);
b. adding the prepared graphite powder into a mixing cavity of a disc mixer through a hopper, adding ethylene glycol, starting a mixing device to mix for 15min to obtain a uniform mixture of the graphite powder and the ethylene glycol, stopping the mixing device, adding the prepared metal catalyst powder into the mixing cavity through the hopper and a feed inlet, and starting the mixing device to mix for 30min to obtain the uniform mixture of the graphite powder and the metal catalyst powder;
in the process, the working power of the mixing device is 18kW, and the rotating speed of the disc mixer is 24rpm in the working process;
c. b, placing the mixture obtained in the step b into a double-roller granulator for granulation, wherein the working rotating speed is 42 revolutions per minute, and raw material granules are obtained after granulation, and the particle size of the obtained raw material granules is 2 mm;
d. c, placing the raw material particles obtained in the step c into a hydrogen reduction furnace, and reducing for 6 hours at the temperature of 1060 ℃ to obtain reduced raw material particles;
e. placing the reduced raw material particles into a full-automatic hydraulic press for pressing, wherein the working pressure of the press is 40Mpa, and obtaining a first mixed layer block of graphite and catalyst powder with the diameter of 55mm and the height of 10 mm;
(3) preparation of third mixed layer block of graphite and catalyst powder
And (3) repeating the step (2) to prepare a third mixed layer block of graphite and catalyst powder.
(4) Preparation of second mixed layer block of graphite and catalyst powder
a. Preparing raw materials: 12Kg of high-purity graphite powder, 120g of ethylene glycol and 8Kg of metal catalyst powder prepared in the step (1);
b. adding the prepared graphite powder into a mixing cavity of a disc mixer through a hopper, adding ethylene glycol, starting a mixing device to mix for 18min to obtain a uniform mixture of the graphite powder and the ethylene glycol, stopping the mixing device, adding the prepared metal catalyst powder into the mixing cavity through the hopper and a feed inlet, and starting the mixing device to mix for 25min to obtain the uniform mixture of the graphite powder and the metal catalyst powder;
in the process, the working power of the mixing device is 18kW, and the rotating speed of the disc mixer is 24rpm in the working process;
c. b, placing the mixture obtained in the step b into a double-roller granulator for granulation at the rotating speed of 42 revolutions per minute, and obtaining raw material particles after granulation, wherein the particle size of the obtained raw material particles is 2 mm;
d. c, placing the raw material particles obtained in the step c in a hydrogen reduction furnace, and reducing for 7 hours at 1050 ℃ to obtain reduced raw material particles;
e. placing the reduced raw material particles into a full-automatic hydraulic press for pressing, wherein the working pressure of the press is 40Mpa, and obtaining a second mixed layer block of graphite and catalyst powder, the diameter of which is 55mm, and the height of which is 24 mm;
(5) preparation of diamond synthetic column
And sequentially and parallelly superposing the prepared graphite and catalyst powder first mixed layer block, the graphite and catalyst powder second mixed layer block and the graphite and catalyst powder third mixed layer block from bottom to top to obtain the gradient functionalized diamond synthetic column.
Example 4
A preparation method of the gradient functionalized diamond synthesis column comprises the following steps:
(1) preparing metal catalyst powder with the particle size of 400 meshes, wherein the raw materials and the dosage ratio for preparing the metal catalyst powder are as follows: 68.15% Fe, 30% Ni, 1.5% Co, 0.3% Mn, 0.05% La;
(2) preparation of first mixed layer block of graphite and catalyst powder
a. Preparing raw materials: 12.5Kg of high-purity graphite powder, 120g of ethylene glycol and 7.5Kg of metal catalyst powder prepared in the step (1);
b. adding the prepared graphite powder into a mixing cavity of a disc mixer through a hopper, adding ethylene glycol, starting a mixing device to mix for 25min to obtain a uniform mixture of the graphite powder and the ethylene glycol, stopping the mixing device, adding the prepared metal catalyst powder into the mixing cavity through the hopper and a feed inlet, and starting the mixing device to mix for 25min to obtain the uniform mixture of the graphite powder and the metal catalyst powder;
in the process, the working power of the mixing device is 18kW, and the rotating speed of the disc mixer is 24rpm in the working process;
c. b, placing the mixture obtained in the step b into a double-roller granulator for granulation at the rotating speed of 42 revolutions per minute, and obtaining raw material particles after granulation, wherein the particle size of the obtained raw material particles is 2 mm;
d. c, placing the raw material particles obtained in the step c into a hydrogen reduction furnace, and reducing for 7 hours at the temperature of 1060 ℃ to obtain reduced raw material particles;
e. placing the reduced raw material particles into a full-automatic hydraulic press for pressing, wherein the working pressure of the press is 40Mpa, and obtaining a first mixed layer block of graphite and catalyst powder with the diameter of 55mm and the height of 10 mm;
(3) preparation of third mixed layer block of graphite and catalyst powder
And (3) repeating the step (2) to prepare a third mixed layer block of graphite and catalyst powder.
(4) Preparation of second mixed layer block of graphite and catalyst powder
a. Preparing raw materials: 12Kg of high-purity graphite powder, 120g of ethylene glycol and 8Kg of metal catalyst powder prepared in the step (1);
b. adding the prepared graphite powder into a mixing cavity of a disc mixer through a hopper, adding ethylene glycol, starting a mixing device to mix for 25min to obtain a uniform mixture of the graphite powder and the ethylene glycol, stopping the mixing device, adding the prepared metal catalyst powder into the mixing cavity through the hopper and a feed inlet, and starting the mixing device to mix for 25min to obtain the uniform mixture of the graphite powder and the metal catalyst powder;
in the process, the working power of the mixing device is 18kW, and the rotating speed of the disc mixer is 24rpm in the working process;
c. b, placing the mixture obtained in the step b into a double-roller granulator for granulation at the rotating speed of 42 revolutions per minute, and obtaining raw material particles after granulation, wherein the particle size of the obtained raw material particles is 2 mm;
d. c, placing the raw material particles obtained in the step c into a hydrogen reduction furnace, and reducing for 7 hours at the temperature of 1060 ℃ to obtain reduced raw material particles;
e. placing the reduced raw material particles into a full-automatic hydraulic press for pressing, wherein the working pressure of the press is 40Mpa, and obtaining a second mixed layer block of graphite and catalyst powder, the diameter of which is 55mm, and the height of which is 24 mm;
(5) preparation of diamond synthetic column
And sequentially and parallelly superposing the prepared graphite and catalyst powder first mixed layer block, the graphite and catalyst powder second mixed layer block and the graphite and catalyst powder third mixed layer block from bottom to top to obtain the gradient functionalized diamond synthetic column.
The gradient functionalized diamond synthesis column prepared by the invention is used for preparing diamond by specific application examples, which are as follows:
application example 1
The gradient functionalized diamond synthesis column prepared in the above example is placed in a D800 type cubic press to synthesize high-grade and high-self-sharpening artificial diamond single crystal with the main granularity of 35/40.
In the synthesis process (conventional synthesis process), the primary suspension pressure is 52MPa, the secondary suspension pressure is 65MPa, the synthesis final pressure is 78MPa, the total heating time is 45min, the yield of a single synthesis column is 286 carat, and the synthesis yield is improved by about 5 percent compared with that of the conventional synthesis column; the synthetic quality ratio is more than or equal to 52 percent, wherein the TI value of the HD-9880 single crystal is 86, and the TTI value is 82.
Application example 2
The gradient functionalized diamond synthesis column prepared in the above embodiment is placed in a D800 type cubic press to synthesize high-grade and high-self-sharpening artificial diamond single crystal with the main granularity of 40/45.
In the synthesis process (conventional synthesis process), the primary suspension pressure is 52MPa, the secondary suspension pressure is 65MPa, the synthesis final pressure is 77MPa, the total heating time is 40min, the yield of a single synthesis column is 295 carat, and the synthesis yield is improved by 10% compared with that of the conventional catalyst; the synthetic quality ratio is more than or equal to 55 percent, wherein the TI value of the HD-9880 single crystal is 84, and the TTI value is 81.
Application example 3
The gradient functionalized diamond synthesis column prepared in the above embodiment is placed in a D800 type cubic press to synthesize high-grade and high-self-sharpening artificial diamond single crystal with the main granularity of 45/50.
In the synthesis process, the primary suspension pressure is 52MPa, the secondary suspension pressure is 65MPa, the synthesis final pressure is 77MPa, the total heating time is 40min, the yield of a single synthesis column is 298 carat, and the synthesis yield is improved by 10% compared with that of the conventional catalyst; the synthetic quality ratio is more than or equal to 53 percent, wherein the TI value of the HD-9860 single crystal is 85, and the TTI value is 81.
From the above, it can be seen that: the invention adopts a better mixing device and reasonable exploration design, so that the quality and the yield of the synthetic diamond can be obviously improved in the diamond synthesis of the obtained gradient functionalized diamond synthetic column, and the synthetic quality and the yield improvement difficulty of high-grade diamond, especially high-grade high-self-sharpening diamond are great in the diamond synthesis.
Claims (2)
1. A diamond synthetic column with gradient function is characterized in that the synthetic column comprises a first mixed layer block (1) of graphite and catalyst powder, a second mixed layer block (2) of graphite and catalyst powder, which is arranged on the first mixed layer block (1) in parallel, and a third mixed layer block (3) of graphite and catalyst powder, which is arranged on the second mixed layer block (2) in parallel; the diameters of the first mixed layer block (1), the second mixed layer block (2) and the third mixed layer block (3) are equal;
the height of the graphite and catalyst powder first mixed layer block (1) and the height of the graphite and catalyst powder third mixed layer block (3) are equal and lower than the height of the graphite and catalyst powder second mixed layer block (2); the height of the second mixed layer block (2) of the graphite and the catalyst powder is 2.2-2.5 times of that of the first mixed layer block (1) of the graphite and the catalyst powder;
the mass ratio of the graphite to the catalyst powder in the first mixed layer block (1) of the graphite and the catalyst powder and the mass ratio of the graphite to the catalyst powder in the third mixed layer block (3) of the graphite and the catalyst powder are the same; the mass ratio of the graphite to the catalyst powder in the graphite and catalyst powder second mixed layer block (2) is 0.5-1.0 times of the mass ratio of the graphite to the catalyst powder in the graphite and catalyst powder first mixed layer block (1); the proportion of graphite powder in the first mixed layer block (1) and the third mixed layer block (3) is higher than that of the second mixed layer block (2), and the first mixed layer block and the third mixed layer block are used for increasing heat input quantity provided by an external heating source, increasing direct heat productivity of graphite, increasing heat input quantity from two ends of a diamond synthetic column to a middle area, increasing temperature of the center area of the diamond synthetic column and improving axial temperature difference of the synthetic column;
the mass ratio of graphite to catalyst powder in the graphite and catalyst powder first mixed layer block (1) and the graphite and catalyst powder third mixed layer block (3) is 62-70: 30-38 parts of; the mass ratio of graphite to catalyst powder in the graphite and catalyst powder second mixed layer block (2) is 60-55: 40-45;
wherein the graphite is high-purity graphite powder with the particle size of 300 meshes;
the catalyst powder comprises the following raw materials in parts by weight: fe 68.15%, Ni 30%, Co 1.5%, Mn 0.3% and La 0.05%; the particle size is 400 meshes.
2. A method for preparing the gradient functionalized diamond synthesis column of claim 1, which comprises the steps of material mixing, granulation, reduction treatment and cold press molding; the method is characterized by comprising the following specific steps:
(1) preparing a first mixed layer block of graphite and catalyst powder and a third mixed layer block of graphite and catalyst powder:
a. adding required raw materials of graphite powder, catalyst powder and ethylene glycol into a mixing device for mixing; the mass ratio of the graphite powder to the catalyst powder to the ethylene glycol is 62-70: 30-38: 0.12;
the mixing method comprises the following specific steps: putting the prepared graphite powder into a mixing device, adding ethylene glycol, uniformly mixing, stopping the machine, adding catalyst powder, starting the machine, and uniformly mixing to obtain a uniform mixture;
mixing the graphite powder and the ethylene glycol in a mixing device for 15-25 min, and mixing the graphite powder and the ethylene glycol after adding the catalyst powder for 20-30 min; during material mixing, the power of a motor is 15-20 kW, and the rotating speed of the motor is 0-50 rpm;
b. b, granulating the mixed material obtained in the step a to obtain raw material particles; the granulation is carried out in a pair-roller granulator, the working rotating speed of the granulator is 42 revolutions per minute, and the particle size of the raw material particles obtained after the granulation is finished is 2 mm;
c. c, reducing the raw material particles obtained in the step b to obtain reduced particles; the reduction treatment is carried out in a hydrogen reduction furnace, the temperature of the raw material particles during reduction is 1000-1100 ℃, and the reduction time is 6-8 hours;
d. c, performing cold press molding on the reduced particles obtained in the step c to obtain a first mixed layer block of graphite and catalyst powder; the cold press molding is carried out in an automatic hydraulic press for press molding, and the working pressure of the automatic hydraulic press is 40 MPa;
e. repeating the steps a, b, c and d to prepare a third mixed layer block of graphite and catalyst powder;
(2) preparing a second mixed layer block of graphite and catalyst powder:
preparing a second mixed layer block of graphite and catalyst powder according to the step in the step (1); in the preparation process of the graphite and catalyst powder second mixed layer block, the mass ratio of the graphite powder, the catalyst powder and the glycol is as follows: 60-55: 40-45: 0.12;
(3) and (3) stacking the graphite and catalyst powder first mixed layer block, the graphite and catalyst powder second mixed layer block and the graphite and catalyst powder third mixed layer block prepared in the steps (1) and (2) in parallel from bottom to top to obtain the gradient functionalized diamond synthetic column.
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| CN203291781U (en) * | 2013-05-25 | 2013-11-20 | 揭东巴黎万株纱华纺织有限公司 | Mixing device |
| CN104128128B (en) * | 2014-08-12 | 2016-01-20 | 山东聊城莱鑫粉末材料科技有限公司 | A kind of diamond synthesizing split stem stem and preparation method thereof |
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| CN2289598Y (en) * | 1997-04-01 | 1998-09-02 | 郑州工业高等专科学校 | Diamond synthetic coupon |
| CN201906592U (en) * | 2010-07-15 | 2011-07-27 | 山东聊城昌润超硬材料有限公司 | Composite core column for synthetic diamond |
| CN104264210A (en) * | 2014-09-12 | 2015-01-07 | 河南省力量新材料有限公司 | Synthetic method of ultrafine-grain diamond monocrystalline |
| CN204996378U (en) * | 2015-09-18 | 2016-01-27 | 浙江吴越人家新材料有限公司 | Mixing stirrer |
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