CN111829849A - Method for directly synthesizing high-purity and high-density chalcopyrite block material by solid-phase reaction - Google Patents
Method for directly synthesizing high-purity and high-density chalcopyrite block material by solid-phase reaction Download PDFInfo
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- CN111829849A CN111829849A CN202010725174.XA CN202010725174A CN111829849A CN 111829849 A CN111829849 A CN 111829849A CN 202010725174 A CN202010725174 A CN 202010725174A CN 111829849 A CN111829849 A CN 111829849A
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- DVRDHUBQLOKMHZ-UHFFFAOYSA-N chalcopyrite Chemical compound [S-2].[S-2].[Fe+2].[Cu+2] DVRDHUBQLOKMHZ-UHFFFAOYSA-N 0.000 title claims abstract description 77
- 229910052951 chalcopyrite Inorganic materials 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims abstract description 30
- 239000000463 material Substances 0.000 title claims abstract description 27
- 238000003746 solid phase reaction Methods 0.000 title claims abstract description 27
- 230000002194 synthesizing effect Effects 0.000 title claims abstract description 16
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 41
- 239000010439 graphite Substances 0.000 claims abstract description 41
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 33
- 238000006243 chemical reaction Methods 0.000 claims abstract description 28
- 238000000227 grinding Methods 0.000 claims abstract description 19
- 239000000203 mixture Substances 0.000 claims abstract description 15
- OMZSGWSJDCOLKM-UHFFFAOYSA-N copper(II) sulfide Chemical compound [S-2].[Cu+2] OMZSGWSJDCOLKM-UHFFFAOYSA-N 0.000 claims abstract description 14
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 claims abstract description 12
- 238000005498 polishing Methods 0.000 claims abstract description 12
- 239000000843 powder Substances 0.000 claims abstract description 12
- 238000007789 sealing Methods 0.000 claims abstract description 10
- 239000002994 raw material Substances 0.000 claims abstract description 8
- 238000003825 pressing Methods 0.000 claims abstract description 7
- 238000002156 mixing Methods 0.000 claims abstract description 5
- 238000007605 air drying Methods 0.000 claims abstract description 4
- INPLXZPZQSLHBR-UHFFFAOYSA-N cobalt(2+);sulfide Chemical compound [S-2].[Co+2] INPLXZPZQSLHBR-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000011261 inert gas Substances 0.000 claims abstract description 4
- 238000003860 storage Methods 0.000 claims abstract description 4
- AFNRRBXCCXDRPS-UHFFFAOYSA-N tin(ii) sulfide Chemical compound [Sn]=S AFNRRBXCCXDRPS-UHFFFAOYSA-N 0.000 claims abstract description 4
- 238000005303 weighing Methods 0.000 claims abstract description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 34
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 29
- 229910052697 platinum Inorganic materials 0.000 claims description 18
- 235000012431 wafers Nutrition 0.000 claims description 16
- 230000015572 biosynthetic process Effects 0.000 claims description 13
- 238000003786 synthesis reaction Methods 0.000 claims description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- 239000013590 bulk material Substances 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 6
- 229910052718 tin Inorganic materials 0.000 claims description 5
- 230000035484 reaction time Effects 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 claims description 3
- 229910003460 diamond Inorganic materials 0.000 claims description 3
- 239000010432 diamond Substances 0.000 claims description 3
- 238000011068 loading method Methods 0.000 claims description 3
- 238000004506 ultrasonic cleaning Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 abstract description 5
- 239000010941 cobalt Substances 0.000 abstract description 5
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 abstract description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 abstract description 4
- 230000005540 biological transmission Effects 0.000 abstract description 4
- 238000012360 testing method Methods 0.000 abstract description 2
- 238000004140 cleaning Methods 0.000 abstract 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 14
- 239000011707 mineral Substances 0.000 description 14
- 238000005245 sintering Methods 0.000 description 10
- 229910052717 sulfur Inorganic materials 0.000 description 10
- 239000011593 sulfur Substances 0.000 description 10
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 239000010949 copper Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 239000002245 particle Substances 0.000 description 6
- 239000012071 phase Substances 0.000 description 6
- 229910052683 pyrite Inorganic materials 0.000 description 6
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 6
- 239000013078 crystal Substances 0.000 description 5
- 238000006477 desulfuration reaction Methods 0.000 description 5
- 230000023556 desulfurization Effects 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000001788 irregular Effects 0.000 description 3
- 229910052960 marcasite Inorganic materials 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 description 3
- 239000011028 pyrite Substances 0.000 description 3
- 229910052903 pyrophyllite Inorganic materials 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 150000004763 sulfides Chemical class 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052948 bornite Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 229910052947 chalcocite Inorganic materials 0.000 description 1
- 238000009388 chemical precipitation Methods 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 229910052971 enargite Inorganic materials 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229910052952 pyrrhotite Inorganic materials 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- WGPCGCOKHWGKJJ-UHFFFAOYSA-N sulfanylidenezinc Chemical group [Zn]=S WGPCGCOKHWGKJJ-UHFFFAOYSA-N 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/32—Polishing; Etching
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/34—Purifying; Cleaning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
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- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2866—Grinding or homogeneising
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
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- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2873—Cutting or cleaving
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Abstract
The invention discloses a method for directly synthesizing a high-purity and high-density chalcopyrite block material by solid-phase reaction, which comprises the steps of weighing analytically pure copper sulfide and analytically pure ferrous sulfide according to a molar ratio of 1:1, and uniformly grinding and mixing the materials to serve as starting raw materials; pressing the mixture powder into a cylinder, covering the end face with a sulfur powder wafer, sequentially filling the sulfur powder wafer, the mixture cylinder and the sulfur powder wafer into a platinum-graphite double-sample cavity, sealing to prepare a sample, placing the sample into an h-BN tube, and taking the h-BN as a pressure transmission medium; carrying out high-temperature high-pressure reaction on a cubic apparatus press, taking out a reacted cylindrical sample, polishing, ultrasonically cleaning, air-drying, and then placing in an inert gas atmosphere for storage. The density of the obtained chalcopyrite block material is close to the theoretical density, the chalcopyrite block material presents a standard cylindrical shape and can be directly used for testing the electrical conductivity and the thermal conductivity, in addition, one or two of tin sulfide or cobalt sulfide is added into the raw material, the chalcopyrite derivative doped with tin and cobalt can be formed, and the electromagnetic property of the chalcopyrite can be optimized.
Description
Technical Field
The invention relates to a method for directly synthesizing a high-purity and high-density chalcopyrite block material by a solid-phase reaction, belonging to the field of material science research.
Background
Chalcopyrite is a copper-iron sulfide which is distributed all over the world, belongs to a typical hydrothermally-produced mineral, and is an important copper ore resource. The natural chalcopyrite mostly presents irregular granular and compact blocky aggregates, and the crystals are very rare. The crystal structure is a tetragonal crystal system and is a zinc blende structure, Cu and Fe are respectively positioned at the vertex angle of a tetrahedron, the Cu and the Fe are linked by S, and the chemical formula is CuFeS2. Chalcopyrite has good conductivity, belongs to semiconductors, and the research on the electrochemical properties of chalcopyrite has extremely important significance for explaining hydrothermal formation, electrolytic destruction, wet-process copper smelting and the like. More importantly, the chalcopyrite has high electrical conductivity and extremely high thermal conductivity, and is a thermoelectric material with great potential. The exploration of thermoelectric materials with high conversion efficiency can realize the mutual conversion of heat energy and electric energy, and is the key for searching novel clean energy and developing energy conversion technology. Therefore, the electrical and thermal conductivities of chalcopyrite are the core of the study of its properties, and in the absence of large-size crystals, high-purity, high-density chalcopyrite bulk materials are considered as the best carriers for studying their electrothermal transport properties.
At present, the sources of chalcopyrite are mainly natural ore dressing and artificial synthesis. The natural ore dressing is to crush the natural chalcopyrite aggregate into 100-200 meshes, select relatively pure particles under a mineral phase mirror, grind and pre-press the particles, recrystallize the particles at high temperature and high pressure, sinter the particles into compact blocks, polish and process the blocks to prepare chalcopyrite electrodes, and study the electrochemical corrosion property of the chalcopyrite electrodes. Natural mineral separation is accepted by the field of geosciences because its research goal is experimental simulation of natural minerals. However, for the quantitative research of thermoelectric materials in the field of materials science, natural mineral separation has the disadvantages that the purity of natural chalcopyrite cannot be guaranteed and the components cannot be controlled, and the reasons are as follows: (1) the natural chalcopyrite symbiotic minerals comprise pyrite, pyrrhotite, bornite, chalcocite, enargite and the like, and although the beneficiation method can select relatively pure chalcopyrite particles from the symbiotic mineral aggregate, most of the symbiotic minerals are in the micron grade, and the substances in the symbiotic minerals are different, so that the symbiotic minerals are difficult to identify through mineral dressing by a mineral phase mirror. (2) The influence of the forming environment on natural chalcopyrite is often accompanied by the micro substitution of various elements such as Ag, Au, Se, Te, Sn, Ni, Co and the like, which leads the chemical components not to be controlled artificially. Since the thermoelectric properties of semiconductor materials depend strongly on impurities and components, quantitative studies on the thermoelectric properties can only be made by artificially synthesizing a high-purity chalcopyrite mother liquor phase under the condition of artificially controlling doping components, and in fact, natural mineral separation cannot meet the material science standard. The artificial synthesis mainly uses a hydrothermal chemical precipitation method at present to obtain the high-purity chalcopyrite nano material. However, the problem of the nano chalcopyrite is that the particles are small and the porosity is large, and the dielectric effect of the nano particles can not measure the thermoelectric transport property.
The solid phase reaction method is the most basic synthesis method in the field of materials, and means that a target product is generated by sintering a starting material at a high temperature and performing a solid phase diffusion reaction. Most commonly, two oxides are formed into the desired product by a solid phase reaction method, for example, copper oxide CuO and strontium oxide SrO (strontium oxide SrO is obtained by decomposing strontium carbonate) are mixed at a molar ratio of 1:1, and directly sintered at 980 ℃ for 12 hours by a solid phase reaction method to form copper oxide SrCuO2. We can think about whether we can go through analogy with SrCuO2The solid phase reaction of (1) mixing copper sulfide CuS and ferrous sulfide FeS according to the molar ratio of 1:1, and directly sintering by utilizing the solid phase reaction to generate chalcopyrite CuFeS2Is there a In fact, this reaction is very difficult to control experimentally due to the poor chemical stability of the sulfide, since (1) the sintering of CuS and FeS in air, completely distinguished from the solid-phase reaction of oxides, results in the direct oxidation of CuO, Fe2O3And SO2Cannot generate CuFeS2. (2) The problem that part of materials are easy to oxidize can be effectively solved by using a quartz vacuum tube sealing technology, for example, iron-based superconducting 111-type LiFeAs can be obtained by directly sintering lithium powder Li, iron powder Fe and arsenic powder As in a vacuum tube. However, elemental sulfur S is very volatile compared to heavier arsenic As. During the high-temperature sintering process, sulfide can undergo auto-oxidation reduction to carry out desulfurization reaction, and sulfur is extremely easy to volatilize to cause loss. Specifically, the Cu-S bond is weaker than the Cu-O bond, and is easy to break at high temperature to release elemental sulfur: CuS → Cu2S+S,CuFeS2→(Cu2+,Cu-)FeS2- + S. The higher the sintering temperature and the longer the sintering time, the more severe the desulfurization reaction. Therefore, although the vacuum tube can avoid the oxidation of the sulfide, the open system can not solve the problems of desulfurization reaction and elemental sulfur volatilization, so that the solid-phase reaction is difficult to be carried out according to the stoichiometric proportion of the chalcopyrite, and the purity of the product can not be ensured.
Disclosure of Invention
The invention aims to solve the problems and provide a method for directly synthesizing a high-purity and high-density chalcopyrite bulk material by using a solid-phase reaction method at high temperature and high pressure so as to solve the technical problem of the conventional chalcopyrite semiconductor research.
The purpose of the invention is realized by the following technical scheme: a method for directly synthesizing a high-purity and high-density chalcopyrite block material by solid-phase reaction comprises the following steps:
step 1, weighing analytically pure copper sulfide (CuS) and analytically pure ferrous sulfide (FeS) according to a molar ratio of 1:1, and grinding and uniformly mixing the materials to obtain an initial raw material;
step 2, pressing the mixture powder in the step 1 into a cylinder with phi 5mm multiplied by 5mm by using a powder tablet press, pressing analytically pure sulfur powder S into wafers with phi 5mm multiplied by 0.5mm by using the powder tablet press, and preparing two sulfur powder wafers;
step 3, putting the mixture cylinder and the sulfur powder wafer pre-pressed in the step 2 into a platinum-graphite double-sample cavity, sealing to prepare a sample, wherein the sample cavity is a sulfur powder wafer-mixture cylinder-sulfur powder wafer in the sequence from top to bottom, preparing the sample, and putting the prepared sample into an h-BN pipe, wherein h-BN is used as a pressure transmission medium;
step 4, assembling the h-BN pipe provided with the sample in the step 3 in a high-pressure synthesis assembly block and placing the h-BN pipe in a cubic apparatus large press for high-temperature high-pressure reaction;
step 5, taking out the sample reacted in the step 4, cutting platinum by using a diamond cutter, stripping a platinum-graphite double-sample cavity, and taking out a chalcopyrite cylindrical bulk material sample;
and 6, grinding and polishing the upper bottom surface, the lower bottom surface and the side surface of the chalcopyrite cylindrical block sample, placing the chalcopyrite cylindrical block sample in acetone for ultrasonic cleaning for 5 minutes, and placing the chalcopyrite cylindrical block sample in an inert gas atmosphere for storage after air drying. And grinding and polishing the side surface of the block sample, namely adhering the block sample to a grinding machine rod, grinding and polishing the side surface of the block sample by using a grinding machine, and grinding and polishing the polished cylindrical chalcopyrite sample. And completely removing black substances remained on the outer surface of the block sample by high-temperature and high-pressure reaction through grinding and polishing the outer surface of the block sample.
Further, the manufacturing of the platinum-graphite double-sample cavity in the step 3 specifically comprises the following steps: the hollow graphite tube and the graphite sheets at the pipe orifices at the two ends form a graphite inner cavity, and the graphite inner cavity is fastened by a platinum snap fastener.
Further, the sample loading process in step 3 specifically comprises: placing a sulfur powder wafer-mixture cylinder-sulfur powder wafer sample in a graphite inner cavity, sealing by using an outer sample cavity platinum snap fastener to form double sample cavities, placing the double sample cavities in an h-BN tube, sealing by using an h-BN sheet, and finally assembling the h-BN tube in a high-pressure synthesis assembly block.
Further, the temperature of the high-temperature high-pressure reaction in the step 4 is 400 ℃, the pressure is 0.2GPa, and the reaction time is 15 minutes.
Furthermore, one or two of tin sulfide SnS or cobalt sulfide CoS is/are added into the raw material in the step 1, so that the chalcopyrite derivative doped with tin Sn and cobalt Co can be formed.
The invention has the beneficial effects that:
1. the design of the fully-closed double-sample-cavity assembly solves the problem of poor chemical stability of sulfide by controlling the high-temperature and high-pressure reaction conditions, and the solid-phase reaction is very difficult to perform experimentallyThe problem of control. Specifically, the graphite-platinum double-sample cavity is assembled to form a completely closed system under the conditions of high temperature and high pressure, and the functions of the system are as follows: (1) the graphite sample cavity is an inner sample cavity, and has strong adsorbability and lubricity at high temperature and high pressure. The device can completely adsorb residual oxygen in the sample cavity, control the oxygen loss degree and the reducibility of the sample cavity and ensure that sulfides are not oxidized. Meanwhile, the sulfur sheets added on the upper bottom surface and the lower bottom surface of the sample can volatilize at high temperature, the inner wall of the graphite cavity can adsorb volatilized sulfur, a layer of sulfur protective film is formed on the whole graphite-sample interface to control the sulfur loss, and the sulfur desulfurization reaction of sulfide is inhibited by utilizing the environment saturated by sulfur volatile matters. In addition, the graphite sample cavity has strong lubricity, can be well attached to the outer wall of the sample, effectively separates the sample from the platinum outer sample cavity, and avoids direct contact of sulfide and corrosion of platinum. (2) The platinum sample cavity is an outer sample cavity, and has extremely strong ductility and plasticity under high temperature and high pressure. The graphite sample cavity is wrapped by the sulfur diffusion-proof device to form a completely closed system, and sulfur in the cavity cannot diffuse to the outside. Meanwhile, the graphite sample cavity is easy to generate irregular deformation under the influence of temperature and pressure gradient, and the plasticity of the platinum sample cavity ensures that the sample cavity is cylindrical, so that the irregular deformation is avoided. In addition, the platinum sample cavity effectively separates the graphite sample cavity from the pressure transmission medium h-BN, and the graphite is prevented from diffusing on an h-BN interface at high temperature. By combining the above (1) and (2), the graphite-platinum double-sample cavity assembly designed by us is based on the premise of controlling oxygen fugacity and sulfur fugacity, and under the completely closed environment of high temperature and high pressure, oxidation and desulfurization reactions are avoided to ensure the stability of sulfide, so that CuS and FeS can react according to the molar ratio of 1:1 to generate CuFeS2。
2. Besides the design of double sample cavities, the control of high-temperature and high-pressure reaction conditions is also a key factor for synthesizing chalcopyrite by a solid phase method. We found through a lot of experiments that the pressure of 0.2GPa, the temperature of 400 ℃, the reaction time of 15min are the best reaction conditions, because: (1) chalcopyrite belongs to submarine hydrothermal fluid causative minerals and can be stable under the pressure of hundreds of megapascals MPa, but the high-pressure stability of the chalcopyrite is far less than that of chalcopyrite FeS2It is currently reported that pyrite can maintain nodules at pressures of up to hundred gigapascal GPaThe structure is stable, which makes the formation of pyrite prone at higher pressures. If the pressure is too high, side reactions can occur: 2CuS + FeS → Cu2S+FeS2No chalcopyrite CuFeS can be formed2. Therefore, the reaction pressure is set to be 0.2GPa, which is close to the hydrothermal formation pressure of the chalcopyrite seabed, and the pressure is the lowest pressure which can be set by the cubic press. (2) The cubic press reaction temperature is generally set at intervals of at least 50 ℃ due to the temperature gradient. We found that, with a reaction temperature of 350 ℃, the solid phase reaction was incomplete and the product had small amounts of starting phases CuS and FeS remaining in addition to chalcopyrite. The reaction temperature was set at 450 ℃ and the product contained very little FeS in addition to chalcopyrite2. The reaction temperature is set to be 400 ℃, the solid phase reaction is ideal, and the product is pure chalcopyrite and has no impurity phase. (3) The pressure can greatly reduce the reaction activation energy and promote the reaction rate, so that the solid phase reaction of CuS and FeS can be rapidly carried out within 15min, and the factor of unstable chemical property caused by long-time sintering of the chalcopyrite is prevented. Compared with the prior art, the solid-phase reaction rate under normal pressure is much slower, and the sintering time is generally not less than 12 h.
3. The density of the chalcopyrite bulk material obtained by the method is 4.2g/cm3Near theoretical density of 4.3g/cm3And the standard cylindrical shape is presented, and the method can be directly used for testing the electrical conductivity and the thermal conductivity under the condition of determining geometric parameters. Through the design of double sample cavities and the control of high-temperature and high-pressure conditions, on the premise of ensuring the stability of sulfides, a high-purity and high-density chalcopyrite bulk material standard sample is directly synthesized by solid-phase reaction sintering, and the method aims at researching the thermoelectric property of chalcopyrite and thoroughly solves the problems of the traditional natural ore dressing method and hydrothermal synthesis method.
4. The solid phase reaction for synthesizing the chalcopyrite also solves the technical problem of synthesizing the chalcopyrite-doped derivative, the thermoelectric property and the component of the chalcopyrite are closely related, the artificial adjustment of the chalcopyrite component is crucial to the optimization of the thermoelectric property, and the high-purity chalcopyrite CuFeS is used2As a matrix phase, the crystal structure is doped with elements such as tin Sn, cobalt Co and the like, and the corresponding chalcopyrite-forming derivatives: tin-chalcopyrite (Cu,Sn)FeS2cobalt chalcopyrite Cu (Fe, Co) S2And the like, and these derivatives have more excellent thermoelectric properties. The synthesis of the derivative bulk samples can be completed by only adding corresponding sulfide raw materials such as SnS, CoS and the like in the chalcopyrite solid-phase reaction.
The invention is further illustrated by the following specific examples.
Detailed Description
Examples
A method for directly synthesizing a high-purity and high-density chalcopyrite block material by solid-phase reaction comprises the following steps:
step 1, weighing analytically pure copper sulfide (CuS) and analytically pure ferrous sulfide (FeS) according to a molar ratio of 1:1, and grinding and uniformly mixing the materials to obtain an initial raw material;
step 2, pressing the mixture powder in the step 1 into a cylinder with phi 5mm multiplied by 5mm by using a powder tablet press, pressing analytically pure sulfur powder S into wafers with phi 5mm multiplied by 0.5mm by using the powder tablet press, and preparing two sulfur powder wafers;
step 3, putting the mixture cylinder and the sulfur powder wafer pre-pressed in the step 2 into a platinum-graphite double-sample cavity, sealing to prepare a sample, wherein the sample cavity is a sulfur powder wafer-mixture cylinder-sulfur powder wafer in the sequence from top to bottom, preparing the sample, and putting the prepared sample into an h-BN pipe, wherein h-BN is used as a pressure transmission medium;
step 4, assembling the h-BN pipe provided with the sample in the step 3 in a high-pressure synthesis assembly block and placing the h-BN pipe in a cubic apparatus large press for high-temperature high-pressure reaction, wherein the temperature is 400 ℃, the pressure is 0.2GPa, and the reaction time is 15 minutes;
step 5, taking out the sample reacted in the step 4, cutting platinum by using a diamond cutter, stripping a platinum-graphite double-sample cavity, and taking out a chalcopyrite cylindrical bulk material sample;
and 6, grinding and polishing the upper bottom surface, the lower bottom surface and the side surface of the chalcopyrite cylindrical block sample, placing the chalcopyrite cylindrical block sample in acetone for ultrasonic cleaning for 5 minutes, and placing the chalcopyrite cylindrical block sample in an inert gas atmosphere for storage after air drying. And grinding and polishing the side surface of the block sample, namely adhering the block sample to a grinding machine rod, grinding and polishing the side surface of the block sample by using a grinding machine, and grinding and polishing the polished cylindrical chalcopyrite sample. And completely removing black substances remained on the outer surface of the block sample by high-temperature and high-pressure reaction through grinding and polishing the outer surface of the block sample.
Further, the assembling process of the sulfur powder wafer-mixture cylinder-sulfur powder wafer sample in the platinum-graphite double-sample cavity in the step 3 specifically comprises the following steps:
step (1): and machining a graphite tube with the inner diameter phi of 5mm, the outer diameter phi of 7mm and the height of 8mm on a lathe. Processing two graphite sheets with the thickness of phi 5mm and the thickness of 1mm on a lathe, wherein a graphite sample inner cavity with the thickness of 1mm is formed by a graphite tube and a pair of graphite sheets;
step (2): processing a platinum snap fastener, wherein the sizes of the secondary opening are phi 7mm, phi 7.2mm and 8.1mm in height, and the sizes of the primary opening are phi 7.2mm, phi 7.4mm and 8.1mm in height;
and (3): a graphite sample cavity is formed by the graphite tube and the graphite sheet, and a platinum-graphite sample cavity is formed by the platinum snap fastener. Two sulfur powder original sheets are placed on the upper bottom surface and the lower bottom surface of the cylindrical sample, placed in a graphite inner sample cavity, and then integrally sealed by a platinum snap fastener;
and (4): drilling a phi 7.4mm hole in the center of a phi 12mm h-BN rod on a lathe to form an h-BN tube, inserting a platinum-graphite sample cavity filled with a sulfur powder wafer-mixture cylinder-sulfur powder wafer sample into the tube, sealing two ends with phi 7.4mm h-BN pieces with the thickness of 2mm, and assembling the h-BN tube in a high-pressure synthesis assembly block.
The specific process of assembling the h-BN pipe in the high-pressure synthesis assembly block in the step (4) is as follows: selecting a pyrophyllite block, and drilling a phi 14mm circular through hole in the center of the pyrophyllite block; a circular graphite heating pipe with the outer diameter phi of 14mm and the inner diameter phi of 12mm is sleeved in the circular through hole; a sample sealed by an h-BN pipe with the diameter of phi 12mm is placed in the middle of the graphite heating pipe; the upper end and the lower end of the round graphite heating furnace are sealed by pyrophyllite plugs.
Furthermore, one or two of tin sulfide SnS or cobalt sulfide CoS is added in the step 1, so that the chalcopyrite derivative doped with tin Sn and cobalt Co can be formed.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (5)
1. A method for directly synthesizing a high-purity and high-density chalcopyrite block material by solid-phase reaction is characterized by comprising the following steps:
step 1, weighing analytically pure copper sulfide (CuS) and analytically pure ferrous sulfide (FeS) according to a molar ratio of 1:1, and grinding and uniformly mixing the materials to obtain an initial raw material;
step 2, pressing the mixture powder in the step 1 into a cylinder with phi 5mm multiplied by 5mm by using a powder tablet press, pressing analytically pure sulfur powder S into wafers with phi 5mm multiplied by 0.5mm by using the powder tablet press, and preparing two sulfur powder wafers;
step 3, putting the mixture cylinder and the sulfur powder wafer pre-pressed in the step 2 into a platinum-graphite double-sample cavity, sealing to prepare a sample, putting the sample cavity into the sulfur powder wafer-mixture cylinder-sulfur powder wafer in sequence from top to bottom to prepare the sample, and putting the prepared sample into the sample cavityhIn a BN pipe, tohBN is a pressure medium;
step 4, loading the sample in step 3hThe BN pipe is assembled in a high-pressure synthesis assembly block and placed in a cubic apparatus large press to carry out high-temperature high-pressure reaction;
step 5, taking out the sample reacted in the step 4, cutting platinum by using a diamond cutter, stripping a platinum-graphite double-sample cavity, and taking out a chalcopyrite cylindrical bulk material sample;
and 6, grinding and polishing the upper bottom surface, the lower bottom surface and the side surface of the chalcopyrite cylindrical block sample, placing the chalcopyrite cylindrical block sample in acetone for ultrasonic cleaning for 5 minutes, and placing the chalcopyrite cylindrical block sample in an inert gas atmosphere for storage after air drying.
2. The method for directly synthesizing the high-purity and high-density chalcopyrite block material through the solid-phase reaction according to the claim 1, wherein the manufacturing of the platinum-graphite double-sample cavity in the step 3 is specifically as follows: the hollow graphite pipe and the graphite sheets with pipe orifices at two ends form a graphite inner cavity, and the graphite inner cavity is fastened by a platinum snap fastener to form a platinum outer cavity.
3. The method for directly synthesizing the high-purity and high-density chalcopyrite block material by the solid-phase reaction according to the claim 1, wherein the loading process in the step 3 is specifically as follows: placing the sulfur powder wafer-mixture cylinder-sulfur powder wafer sample in a graphite inner cavity, sealing with an outer sample cavity platinum snap fastener to form double sample cavities, placing the double sample cavities,hin-BN tubes, withh-BN sheet sealing, finallyhThe BN tubes are assembled in a high pressure synthesis assembly block.
4. The method for directly synthesizing the high-purity and high-density chalcopyrite block material by the solid-phase reaction according to the claim 1, wherein the temperature of the high-temperature and high-pressure reaction in the step 4 is 400 ℃, the pressure is 0.2GPa, and the reaction time is 15 minutes.
5. The method for directly synthesizing the high-purity and high-density chalcopyrite block material by the solid-phase reaction according to claim 1, wherein one or two of tin sulfide SnS or cobalt sulfide CoS is/are added into the raw material of the step 1, so that the chalcopyrite derivative doped with Sn and Co can be formed.
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113373519A (en) * | 2021-06-22 | 2021-09-10 | 中国地质科学院地球物理地球化学勘查研究所 | Nano copper crystal growth experiment simulation device and method |
CN114671454A (en) * | 2022-03-22 | 2022-06-28 | 吉林大学 | Method for synthesizing novel phase chalcocite-H copper sulfide ferromagnetic material at high temperature and high pressure |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103411799A (en) * | 2013-08-26 | 2013-11-27 | 中国科学院地球化学研究所 | Built-in in-situ sampling device for high-temperature and high-pressure reaction kettle |
CN104362296A (en) * | 2014-11-21 | 2015-02-18 | 厦门大学 | Novel sulfenyl material electrode and preparation method and application thereof |
CN105973796A (en) * | 2016-06-24 | 2016-09-28 | 中国科学院地球化学研究所 | Method for preparing chalcopyrite electrode |
CN106829968A (en) * | 2017-03-06 | 2017-06-13 | 河南工业大学 | A kind of method that use phase transition under high pressure method prepares nano-multicrystal stishovite |
CN107675255A (en) * | 2017-09-04 | 2018-02-09 | 中国科学院地球化学研究所 | A kind of method for growing siderite monocrystalline at high temperature under high pressure |
CN109400151A (en) * | 2018-12-19 | 2019-03-01 | 中国科学院地球化学研究所 | A method of preparing doped yttrium barium zirconate proton conductor material at high temperature under high pressure |
-
2020
- 2020-07-24 CN CN202010725174.XA patent/CN111829849B/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103411799A (en) * | 2013-08-26 | 2013-11-27 | 中国科学院地球化学研究所 | Built-in in-situ sampling device for high-temperature and high-pressure reaction kettle |
CN104362296A (en) * | 2014-11-21 | 2015-02-18 | 厦门大学 | Novel sulfenyl material electrode and preparation method and application thereof |
CN105973796A (en) * | 2016-06-24 | 2016-09-28 | 中国科学院地球化学研究所 | Method for preparing chalcopyrite electrode |
CN106829968A (en) * | 2017-03-06 | 2017-06-13 | 河南工业大学 | A kind of method that use phase transition under high pressure method prepares nano-multicrystal stishovite |
CN107675255A (en) * | 2017-09-04 | 2018-02-09 | 中国科学院地球化学研究所 | A kind of method for growing siderite monocrystalline at high temperature under high pressure |
CN109400151A (en) * | 2018-12-19 | 2019-03-01 | 中国科学院地球化学研究所 | A method of preparing doped yttrium barium zirconate proton conductor material at high temperature under high pressure |
CN109400151B (en) * | 2018-12-19 | 2021-01-26 | 中国科学院地球化学研究所 | Method for preparing yttrium-doped barium zirconate proton conductor material at high temperature and high pressure |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113373519A (en) * | 2021-06-22 | 2021-09-10 | 中国地质科学院地球物理地球化学勘查研究所 | Nano copper crystal growth experiment simulation device and method |
CN113373519B (en) * | 2021-06-22 | 2023-09-01 | 中国地质科学院地球物理地球化学勘查研究所 | Nanometer copper crystal growth experimental simulation device and method |
CN114671454A (en) * | 2022-03-22 | 2022-06-28 | 吉林大学 | Method for synthesizing novel phase chalcocite-H copper sulfide ferromagnetic material at high temperature and high pressure |
CN114671454B (en) * | 2022-03-22 | 2022-11-29 | 吉林大学 | Method for synthesizing new-phase chalcocite-H copper sulfide ferromagnetic material at high temperature and high pressure |
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