The production process of diamond powder

Diamond powder crushing and shaping process occupies a very important position in the production of diamond micropowder, which directly affects the shape index of the micropowder and the content of the target particle size. The scientific and reasonable crushing and shaping process can not only quickly crush the coarse-grained (conventional grain size 100-500 microns) diamond raw materials into diamond micro-powder particles with a particle size range of about (0-80 microns), but also optimize the particle shape. , to make the particles of the micropowder product more round and regular, reduce or even completely eliminate the long strip, flake, needle stick and other particles that affect the final quality of the micropowder, so as to maximize the output ratio of the marketable target particle size.

Commonly used diamond powder crushing and shaping methods mainly include: horizontal ball mill dry milling, horizontal ball mill wet milling, jet milling, high-speed stirring ball mill wet milling, planetary ball mill wet milling, etc. Different crushing and shaping methods are selected, and the working principles and process parameters of crushing and shaping are also different. At present, the domestic micropowder enterprises mainly use the horizontal ball mill dry grinding method. Here, only the horizontal ball mill dry grinding method is used as an example to illustrate its production principle and process.

The main process control points of the horizontal ball mill dry grinding method are the ball mill speed, ball-to-material ratio, filling coefficient, steel ball ratio, etc. In actual production, it can be flexibly mastered according to different raw materials and the purpose of crushing and shaping.

In the case of the same cylinder diameter of the ball mill, the higher the rotational speed, the greater the centrifugal force, and the higher the distance that the steel balls are driven to rise along the cylinder wall. The diamond raw material is broken by the collision and impact when the steel ball falls, and the stronger the collision and impact when the steel ball falls, the higher the crushing efficiency. However, when the rotation speed of the cylinder reaches a certain critical value, the steel balls cannot escape from the cylinder and rotate with it, and the ball mill loses its crushing effect. On the contrary, when the speed of the ball mill is low, the distance that the steel ball is driven to rise along the cylinder wall is shorter. At this time, the steel ball mainly acts on the diamond raw material by extrusion and friction, and the shaping effect of the protruding part on the surface of the diamond particle is better. Do not destroy the overall structure of the particles. However, when the speed of the ball mill is too low, the steel balls cannot be lifted to a certain height and then slide down, which has little effect on the diamond raw material and cannot meet the requirements of high-efficiency industrial production.

In the process of crushing and shaping, proper ball-to-material ratio and filling coefficient are very important. Too high or too low ball-to-material ratio and filling coefficient will affect the production efficiency and product quality of the ball mill. If the ball-to-material ratio is too high or the filling coefficient is too low, the feeding amount of a single machine is restricted. If the ratio of ball to material is too low or the filling factor is too high, the time for crushing and shaping needs to be prolonged or even the ideal effect cannot be achieved.
In order to achieve a better crushing and shaping effect, when the ball-to-material ratio and filling factor of the ball mill are determined, steel balls with different diameters should be selected and assembled in proportion to obtain better particle shape and faster crushing and shaping efficiency.

Generally speaking, the crushing effect of large steel balls is good, and the shaping effect of small steel balls is good. Through the proportioning scheme of steel balls with different diameters, the contradiction between efficiency and quality can be well resolved.