SU1560320A1 - Method of selective grinding of mixture of materials of different strength - Google Patents

Abstract

The invention relates to the technology of grinding solid materials and can be used in the production of highly dispersed powders used as pigments and fillers. The aim of the invention is to improve the quality and yield of the target component. The method of selectively grinding a mixture of materials of different strengths is carried out by impact crushing at speeds lower than the critical speed of grinding a stronger material and larger critical speed of a less strong material, followed by dividing the crushed material into two fractions, one of which containing the target component is subjected to repeated grinding, and another fraction with a reduced content of impurities is removed, and crushing the mixture is carried out with the number of consecutive blows 3-6 and the angle of impact of the mat Series 4-25 °. The residue on the 0.105 mm sieve is less than 2.2%; the average particle size is 4-12 microns. 1 tab.

Description

The invention relates to the technology of grinding solid materials and can be used in the production of highly dispersed powders used as pigments and fillers.

The purpose of the invention is to increase the yield and quality of the target component.

During the grinding process, new portions of material get to the processed material at an angle of 4-25 °. At the same time, the less durable material is worn out, and the more durable material that falls into the loose layer does not break. With repeated collisions (3-6), a higher selectivity of the components is achieved.

The high selectivity of comminution of the material makes it possible, when using air separation for its separation, to reduce the loss of the target component and to improve its quality.

For a sliding impact, the impact on the processed material is low; therefore, when the number of collisions is less than three, a significant part of the material does not collapse, which reduces the selectivity of the subsequent separation and increases the loss of the target material. service due to the deterioration of the dynamic balancing of the rotors during operation

When the grinding process is performed with an impact angle less than 4 °, the process becomes difficult to control and eventually the disintegrator clogs with the material being ground.

Increasing the impact angle above 25 ° does not allow obtaining a sufficient degree of grinding of the target component, which is also accompanied by a sharp decrease in the yield of dispersed powder.

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Example 1. 100 kg of material containing 20 wt.% Of industrial ceramics (granule size 5 mm) and 80 wt.% Spent iron oxide catalyst (granule size 4X6 mm) are sent for processing in a disintegrator with an inertial air separator.

The critical grinding rate of ceramics (Wi) M5.4 m / s; catalyst (Y ,, l) -6.4 m / s, the number of impacts 6, the impact angle 6 °. The thin fraction obtained from an air separator in the amount of 79 kg contains 4% of fragmented ceramics and has an average particle size of 0.2 mm.

The coarse fraction in the amount of 19.5 kg contains 12% of the catalyst and has an average particle size of 3.2 mm.

The fine fraction is further crushed in a disintegrator with an initial impact velocity of 60 m / s and a number of impacts 5 (impact angle of 90 °) and 78.5 kg of powder with an average size of 7 microns are obtained. The residue on the 0.105 mm sieve is 1.2%. The test results at various angles of impact and the number of impacts are given in the table.

The target component has an average particle size of 4-12 μm, the residue on the sieve is 0, .10 μm less than 2.2%.

A thin fraction containing less impurities from industrial ceramics produces a more deeply ground powder, which ensures the production of higher quality paintwork materials.

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Claims (1)

Invention Formula 0 A method of selectively grinding a mixture of materials of different strengths by impact crushing at speeds lower than the critical grinding speed of a stronger material and higher critical speed of a less strong material, followed by dividing the crushed material into two fractions, one of which containing the target component is subjected to repeated grinding, and another fraction, with a reduced impurity content, is removed, characterized in that, in order to improve the quality and yield of the target component, crushing the mixture suschestvl dissolved with the number of consecutive beats 3-6 and impingement angle of the material 4-25 °.