Method for synthesizing polycrystalline diamond by dry distillation of plant straw detonation

Abstract

The invention relates to a method for synthesizing polycrystalline diamond by retorting plant straw detonation. The retort plant straw is mixed with high-energy explosive 8701 to make a powder column, and the retort plant straw is phase-transformed into polycrystalline diamond by using the high temperature and high pressure conditions generated at the instant of explosive explosion, and The detonation ash produced by the explosion is chemically purified by the sequential combined oxidation reaction of concentrated sulfuric acid and perchloric acid to remove graphite, amorphous carbon and metal impurities in the detonation ash, and then separated by sedimentation, washed and dried to obtain pure polycrystalline diamond. . Its performance was characterized by XRD phase analysis. Compared with graphite and carbon source, polycrystalline diamond with larger grain size and more complete crystal lattice was obtained by using retort plant straw as an external carbon source, which has better performance. Indicators are also more valuable in actual production applications.

Description

technical field [0001] The invention relates to a method for artificial diamond, in particular to a method for detonating and synthesizing polycrystalline diamond by using retort plant straw as an additional carbon source. Background technique [0002] In 1982, former Soviet scientists Staver and others first used the detonation product method to synthesize nano-diamonds by detonation of negative oxygen balance explosives. Later, people developed the direct detonation method, which mixed the external carbon source with high-energy explosives, and used the high temperature and high pressure conditions generated by the explosion of the explosives to make the external carbon source phase into polycrystalline diamond. The polycrystalline diamond obtained by the detonation method is referred to as DPD (detonation polycrystalline diamond). Under the extreme environmental conditions generated by the explosion, the critical diameter of diamond nucleation is very small, and the carb...

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Problems solved by technology

[0003] At present, we mostly use graphite as an external carbon source, and use the direct detonation method to industrialize polycrystalline diamond, but there are few studies on other types of external carbon sources. There are a large number of plants in nature, and dry distillation of plant straw and graphite have different properties. The crystal structure, the research on the synthesis of polycrystalline diamond by retort straw has not been reported yet. Under this background, the present invention uses different types of plant retort straw as an external carbon source to synthesize polycrystalline diamond by direct detonation method.

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