Diamond micro powder is obtained by crushing and grading coarse grain single crystal diamond. Generally speaking, there are three basic mechanisms for crushing the moderately coarse particles to micrometer or submicron grain, namely, crushing, mechanical impact {high speed (9m / see) of moving particles directly colliding and grinding. The roller type ball mill is a crushing equipment with crushing effect with a proper amount of low speed and mechanical impact. As far as the method is concerned, it is the most common method to use the ball mill to produce diamond micro powder in the diamond crushing process. The ball grinding crushing method has been used for many years in the production of diamond micro powder in China, and it has achieved satisfactory results. But because of the disadvantage of low production efficiency, it is now replaced by a airflow pulverizer. The airflow pulverizer is a working medium with compressed air, and the compressed air is ejected to the crushing chamber through a special supersonic nozzle. The airflow carries the material high speed movement, causing strong collision and friction between the material and the material. The purpose of shearing is to smash. According to the kinetic energy formula, kinetic energy is directly proportional to the square of mass and velocity.  Fragmentation occurs when the force acting on the particle is greater than its failure stress. High velocity impact collision causes particles to break up, while shearing and grinding cause the particles to break up. This crushing method is beneficial to the production of diamond micro powder, because it can produce ideal particle shape. The biggest advantage of the airflow pulverizer is that it is not limited by the speed of the mechanical line. It can produce very high airflow speed, especially the supersonic pulverizer can produce the velocity of several times the velocity of the sonic speed, so it can produce huge kinetic energy, and it is easier to get micron and submicron powder. According to the principle of grinding, this type of machine is promising for the production of diamond micro powder.

Particle size grading is a very important process in the production process of diamond powder. It involves the production efficiency and quality of diamond micro powder. At present, the most widely used method of granularity classification of diamond micro powder is the micro powder produced by the combination of natural sedimentation and centrifugal method. Natural settlement method is a direct application of Stokes's law. According to the principle that the particle size is different in the water, the particle size is different according to the different particle size in the water. By controlling the height of the settlement and the settling time, the particle size is graded. Although the equipment is simple, the operation is easy and the quality is stable, the production cycle is longer and labor is longer. Inefficiency。 To this end, many domestic and foreign manufacturers have studied automatic classification equipment, using computer technology and frequency conversion control technology, setting up four systems with automatic mixing, automatic pumping, automatic water circulation and computer control, all digital design, accurate control, energy saving and electricity saving, with artificial incomparable high efficiency and high reliability. Sex and good manipulation. The efficiency of the separation is 10~20 times higher than that of the manual separation. It has ten significant advantages, such as high automation, fast sorting speed, accurate separation precision, no impurity pollution, unmanned interference, strong product quality stability, good reproducibility, low labor intensity of workers, low labor cost of enterprises and large amount of disposable material. It is in line with the future direction of the micro powder industry.