SU381391A1 - Method of dry preparation of fine-dispersed - Google Patents

Description

This invention relates to npoMbimJieHHocTii building materials.

A known method for the dry preparation of tocdispersed powder by separating it into grinding mills.

The disadvantage of the known method is the ingress of foreign undesirable impurities contained in raw materials into the product during fine grinding, as well as increased wear of the process equipment as a result of the high abrasiveness of impurities present in the raw materials and contamination of the product with metal.

The purpose of the invention is to improve the quality of the finished product.

This is achieved by the fact that the raw material mixture is subjected to preliminary selective impact crushing at speeds

. ,,

where VKP, is the critical grinding rate of the raw material of the base material and Vcr, the critical grinding rate of the main component of the impurity.

The number of consecutive blows does not exceed three. The angle of impact of the material is chosen from 30 to 90 °. The crushed material is divided into two fractions, one of which consisting of the raw material of the base material.

2

subjected to fine grinding in impact mill with a first impact speed in the range of 45-65 m / s and a total number of impacts of 3-6, and another fraction with an elevated impurity content is derived from the process of preparing a high-quality product.

Example 1. Based on the results of the test grinding of chalk in a high-speed impact mill at a first impact speed of 38 m / ssk, the Hia residue with 0.14 mm is 2.3%. At a first impact speed of 53 m / s, the residue on the sieve of 0.14 mm is 0.48% (at speeds above 65 m / s, the residue on the sieve (0.14 mm) does not decrease).

PRI mme R 2. When pre-crushing a gypsum stone containing impurities, followed by separation in grinding mills at a speed of rotation of the working bodies of 45 MJccK and an impact angle of 45 ° in a fine fraction, the CaSO4-2-2H2O content is 88.6% and a large fraction of 52.2%. In the case of an increase in the speed of 79 m / s, the purification rate decreases. In this case, the content of CaSO4-2H2O in fine francium is

79.7%, and in the crooked fraction 58.6%.

At the optimal choice of the collision speed, the content of CaSO4-2H2O in the coarse fraction can be reduced to 38.5%, then the content of CaSO4-2H9O in the fine fraction will be

90%. 3 Subject of the Invention A method of dry preparation of a uniformly dispersed powder by grinding by grinding, characterized in that, in order to improve the quality of the finished product, the raw material mixture is subjected to preliminary selective impact crushing at a speedy rate of x Kp, where Uk is the critical grinding rate of the raw material material; The Critical grinding speed of the main component of the impurity is critical, and the number of consecutive blows does not exceed three, the impact angle of the material is 30 to 90 degrees, and then the crushed material is divided into two fractions, one of which, consisting of raw material of the raw material, is subjected to thin Grinding from the impact mill with the first impact speed in the range of 45-65 m / s and a total number of impacts 3-6, and another fraction with a high content of impurities, is output to the process of preparing a quality product.