Artificial diamond purification technique

Abstract

The invention discloses a process to purify diamond, which comprises the following steps: grinding diamond synthesized block into particles; putting into autoclave; adding into the water solution of sulfuric acid or azotic acid or alcaine with density at 10-20%; reacting at normal temperature for 36-48 h; stripping metal; balling; sluicing; clearing black lead; drying; getting the purified diamond. This method does not use concentrated nitric sulfuric mixed acid and can eliminate a good deal of yellow acid mist, which can improve the safety in industrial process.

Description

technical field [0001] The invention belongs to the technical field of superhard material synthesis and purification, and relates to a synthetic diamond purification process. Background technique [0002] In the known technology, for the purification of superhard materials such as diamond block or cubic boron nitride synthesized by powder method, a high concentration nitric acid mixed acid reaction method is generally used, and the strong oxidizing property of nitric acid mixed acid is used to combine with the metal in the superhard material. React with impurities such as graphite to achieve the purpose of impurity removal and purification. There are following problems in this process method: [0003] 1. The metal contained in the diamond synthesis block and the strong acid are easy to form surface passivation during the reaction process, which requires more than ten repeated cycle operations such as reaction → ball milling → elutriation → reaction, which is labor-intensive...

AI Technical Summary

Problems solved by technology

[0003] 1. The metal and strong acid contained in the diamond synthesis block are easy to form surface passivation during the reaction process, which requires more than ten repeated cycle operations such as reaction → ball milling → elutriation → reaction, which is labor-intensive, time-consuming, and material-intensive

[0004] 2. Impurities such as graphite contained in the diamond synthesis block are also removed through the oxidation reaction of nitric-sulfur mixed acid, therefore, a large amount of concentrated nitric acid and concentrated sulfuric acid are required to be consumed

[0005] 3. During the whole process of synthesis and purification, koji and concentrated nitric-sulfur mixed acid participate in the reaction, producing a large amount of yellow waste gas of nitric-sulfuric acid, causing serious pollution to the production environment and the atmospheric environment, poisoning human health, easily causing harm to operators, and even causing burn accident

[0006] 4. A large amount of waste acid liquid is discharged after the reaction of diamond synthetic block with concentrated acid, which seriously pollutes soil quality, water quality and high cost of sewage treatment