SU1072904A1 - Method of regulation of cement material crushing in ball mill - Google Patents

Abstract

METHOD OF MANAGING GRINDING CEMENT MATERIALS IN BALL MILL comprising changing flow of cement clinker and additives, characterized in that, to improve quality control, calculated by the ratio of the characteristic size of the clinker grain to a characteristic grain size additives measured grindability clinker and additives and calculates the ratio of the grindability of clinker to the grindability of the additive, and the change in the supply of the additive is carried out until the ratio of the characteristic dimensions grains of clinker and the addition of values of 1 -1.3, and the ratio of grindings of clinker and the addition of values of 1.5-2.

Description

 1C

This invention relates to methods for controlling the grinding process of bulk solids in drum mills and tube mills equipped with ball loading. It can be used in the cement, chemical, and other industries of the industry in the joint fine grinding of materials that are different in grindability, in particular, cements of mixed composition, containing cement clinker and hard-to-shrink mineral additives. There is a method of controlling the grinding process of cement materials in ball mills, for example, a method that includes measuring the residence time of components in a mill and alternating input materials, starting with a component with a maximum residence time in mill 1. Use this method to use to determine the residence time of components in radioactive isotope mill, expensive equipment and specially trained personnel. Closest to the proposed technical essence is a method for regulating the grinding process of cement materials in a ball mill, including the change in the supply of cement clinker and additives. In this method, the grinding degree of the finished product is measured, stabilized by changing the input of materials into the mill and dividing the optimal value of the grinding speed constant 2. However, this method does not provide the required control quality when the grinding of clinker and additives of varying grindability, after - 35 As the quality of cement containing clinker and additive is not determined only by the dispersity indices (residue on control sieves, specific surface area), but in significant st depends on the physicochemical properties of materials subjected to grinding and particle size distribution of grindability. The purpose of the invention is to improve the quality of regulation. The goal is achieved in that according to the method of controlling the grinding process of cement materials in a ball mill, which includes changing the supply of cement clinker and additives, calculate the ratio of the characteristic grain size of the clinker to the characteristic grain size of the additive, measure the grindability of the clinker and the additive, and calculate the ratio of grindability the clinker to the grindability of the additive, and the change in the feed of the additive is carried out until the ratio reaches the characteristic sizes of the grains of the clinker and additives value 1 - 1.3, and the ratio of the grindability of clinker and the addition of values 1.5-2. The dryness of the process lies in the fact that the efficiency of the grinding process for mixed cements is determined by the mutual influence of the components. When grinding the starting components, one of which is characterized by high grindability relative to the other, and having a similar characteristic grain size, at the beginning of the grinding process, the components are evenly crushed, and as grinding is reduced, the clinker particles (because the clinker has a low grindability). compared with the additive), the hard-to-grind particles of the additive play the role of micronuclei, which contributes to an increase in the content of fine fractions in the final product. The method is carried out by the following OBV laboratory mill, 0.5x0.56 m in size, using the Giprotsement technique, to conduct a series of experiments to determine the grindability of clinker and additives. As a result of the experiments performed, the characteristic grain size of the clinker and additives is determined. By the ratio d ,,, / dfl, the components are selected for which this value is 1-1.3, and the technological schedule for the production of mixed cements is determined. If the ratio of the characteristic grain size of clinker to the characteristic grain size of the additive is less than one or more than 1.3, the components are unevenly crushed: in the first case, intensive grinding of only the additive, in the second, only clinker, which causes a sharp difference in the particle size of the clinker particles and additives in finished product and as a result - lowering the quality of cement. If the ratio of grindability of clinker to grindability of additive c. 1.5, then due to the close indicators of the characteristics of the grindability of clinker and the additive, the latter will not fulfill the role of a microfine. In the case of the value of the ratio b, / b d 2, there will be observed abrasive wear of the grinding load and the arm grouting of the cement mill. Example 1. As a result of laboratory determinations, the value d, for the clinker of the Mikhailovsky Cement Plant is 205.0 µm, the value d for a crown slag is 214.0 µm, and the grinding value for clinker is 30.9 kg / h / kW, for slag Cherepovets - 20.6 kg / h / kW. the ratio d, y ,, 1Али LM. Vd, respectively, is 1 and 1.5. In this case, the supply of 50% slag ensures the strength of the finished product - 48.0 MPa,

(the strength of the additive-free cement is respectively 49.9 MPa)

Example 2. As a result of laboratory determinations, the djy value for clinker is 205.0 μm, the dd value for sand is 1249.1 μm, the grind amount of clinker is 30.9 kg / h / kW, for sand - 44.1 kg / h / kw, with the ratios yad | 4 and ckp / bd correspondingly being 0.16 and 0.7. In this case, the supply of sand up to 100 ° / o provides. the strength of the finished product is 48.0 MPa (the strength of the additive-free cement is respectively 49.9 MPa)

Example 3. As a result of laboratory research, the dly value for clinker is 758.4 microns, the amount of sand for sand is 574.7 microns, the grindability value for clinker is 46.8 kg / h / kW, for sand - 24.4 kg / h / kw, with these ratios d jd and blude respectively are 1.3 and # 2. In this case, the supply of 10% sand ensures the strength of the finished product

53.7 MPa (the strength of the additive-free cement is 52.0 MPa);

Example 4. As a result of laboratory determinations, dJu, for clinker, is 748.4 microns, the ddl value of slag corresponds to 505.6 microns, the grindability value for clinker is 24.4 kg / h / kW, for slag - 23.7 kg / h / kw, with the ratios dly, / di, and ck / ld, respectively, being 1.5 and 1, and supplying slag to 50% reduces the strength of the finished product to 30.0 MPa (the strength of additive-free cement is 52.0 MPa).

The advantages of the method of controlling the grinding process of cement materials are that, using the determination of the characteristic grain size of clinker and additives and their grindability, it is possible to produce cements with an optimal granulometric composition and recommend starting components for the production of mixed cements during industrial production.

Claims (1)

METHOD FOR REGULATING THE CEMENT MILLING PROCESS Of new materials in a ball mill, including changing the flow of cement clinker and additives, characterized in that, in order to improve the quality of regulation, calculate the ratio of the characteristic grain size of the clinker to the characteristic grain size of the additive, measure the grindability of clinker and additives and calculate the ratio of grindability of clinker to grindability , and the change in the filing of the additive is carried out until the ratio of the characteristic grain sizes of the clinker and the additive reaches 1-1.3, and the ratio clinker sludge and additive values of 1.5-2. m u s o 4 ^