Preparation method of diamond raw material

Abstract

The invention provides a preparation method of a diamond raw material, which includes the steps of: 1) placing a graphite material, containing impurities, in a heating furnace having an oxygen-free and micro-positive pressure environment and provided with a pulse medium-frequency electromagnetic field or high-frequency electromagnetic field; 2) starting the heating furnace, so that the graphite material containing impurities is heated to more than 3300 DEG C at a flash speed due to endogenous pulse eddy current, thereby generating heat; 3) then powering off the heating furnace, maintaining thetemperature for a preset time so that heat is transferred in the furnace; 4) starting the heating furnace again so that the graphite material is heated to more than 3300 DEG C again at the flash speed; 5) powering off the heating furnace, maintaining the temperature for a preset time; 6) repeating the above steps for several times so as to gasify the impurities; 7) removing the gasified impurities to obtain a graphite product, wherein the gasified impurities are condensed to prepare and recover solid impurity nano-particles, inter gas recovered at the same time. The method for purifying and preparing the diamond raw material is economical and environment-friendly and is high-effective and high-quality.

Description

technical field [0001] The invention belongs to the field of non-metallic materials, and relates to a method for preparing diamond raw materials, in particular to a method for preparing diamond raw materials by using pulsed eddy current purification. Background technique [0002] At present, most of graphite is purified by dry method at home and abroad, such as Acheson intermittent high temperature method, or electromagnetic induction indirect heating purification method. However, due to the backwardness of these purification processes and heating technology and equipment, and the need to add chlorine, fluorine and other substances during the purification process, they have disadvantages such as high energy consumption, environmental pollution, and uneven temperature distribution in the furnace, resulting in unstable product quality. [0003] According to the geological conditions for the formation of natural graphite and the test and analysis of graphite after nearly a hund...

AI Technical Summary

Problems solved by technology

[0004] At present, there are already methods and equipment for using electromagnetic induction to purify graphite at high temperature in my country, such as the invention patent of CN101462716 "Preparation Process for Purifying Natural Graphite by High Temperature Method", and the invention patent of CN1040638C "Natural Graphite High Temperature Chlorination Purification Process" "Etc., the former added chlorine-containing compound-HCL and fluorine-containing compound-HF, and the latter added chlorine gas. Using the above method to purify graphite, not only the labor intensity of the workers is high, the conditions are difficult, the output is low, and the production cost is high. The harmful gas pollutes the environment seriously, and the energy consumption is large (7000-9000kWh / t); Although the production cost of Chinese patent CN201362594 is relatively low, it still has the shortcoming of adding chlorine to pollute the environment; "Continuous Microcrystalline Graphite Purification Production Equipment" discloses a graphite purification production equipment that makes the emissions meet environmental protection requirements, but its production conditions are high temperature and vacuum environment, so it has high production costs, and the production process is difficult to control and difficult to achieve industrial scale. Production and other shortcomings