RU2519136C1 - Grinding intensifier - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: grinding intensifier on the basis of a mixture of alkolamines and alkane diols at the following ratio, wt %: alkolamines - 30-60, alkane diols - 40-70. Alkane diols represent a mix of ethylene glycol, propylene glycol, butylene glycol and polyethylene glycol. Additionally it contains a plasticiser of sulfonate type based on a mixture of oligomer products of condensation of naphthalene sulphonic acid.

EFFECT: usage of a grinding intensifier makes it possible to increase efficiency of mills and to improve characteristics of ground materials with reduced power inputs.

2 cl, 3 ex, 1 tbl

Description

The invention relates to the field of grinding materials, in particular to the compositions of additives used to intensify the grinding of clinker in the production of cement, during the grinding of chamotte, bauxite, corundum, periclase, quartzite, coal, alumina, dolomite, ore and ore concentrates.

Grinding intensifiers are used during grinding in order to reduce energy consumption, increase mill productivity while maintaining the physical and mechanical characteristics of the crushed materials.

The results of the grinding process depend on many factors, such as technical and technological parameters and characteristics of the mill itself, aerodynamic, temperature and humidity conditions of the grinding, physical and technological properties of the milled materials and additives used during grinding. Grinding plants should primarily provide optimal and stable physical and mechanical characteristics of the crushed materials, taking into account the energy efficiency of the grinding process and the design capacity of the mill. Thus, an increase in mill productivity should be considered simultaneously with the quality of the resulting product and the energy characteristics of the grinding unit.

The effect of grinding intensifiers can be divided into two components: changing the grinding parameters in the mill and the effect on the properties of the finished product.

There are various types of intensifying grinding additives:

triethanolamine (TEA), soap-oil, soap stock, sulphite-alcohol bard, etc.

Amines and polyols are most effective. They influence by reducing agglomeration, and also prevent healing of microcracks formed during grinding. The added amount of such intensifiers is only 0.01-1.1% of the weight of the clinker [Taylor X. Chemistry of cement. Per. from English - M .: Mir, 1996. -560 pp.], However, the subsequent use of the obtained ground materials at the stage of production of concrete, refractories leads to a decrease in the strength characteristics of the materials obtained.

Known additive analogue [Application for invention No. US 2006086291 Amine-containing cement processing additives]. In the present invention, an analogue composition for grinding cement includes diamines, such as tetrahydroxylethylene diamine or alkamine, such as triethanolamine or trisopropanolamine.

The disadvantage of the analogue is that as a grinding intensifier it works at high dosages, it does not significantly increase the performance of mills and obtain high values of the strength characteristics of milled materials.

The closest analogue is the additive [FR 2784373, 04/14/2000 Liquid additive for cement comprises tri-isopropanolamine and anti-forming agent]. The additive contains (wt.%): Triisopropanolamine 15-70, tributyl phosphate 1-13, monoethylene glycol 1-70. The additive may contain a sulphonate type plasticizer based on polynaphthalene sulphonate.

The disadvantage of the presented analogue is that the use of this additive does not significantly increase the productivity of mills and obtain high values of specific surface, fluidity, as well as the required fineness (grinding or residue on a sieve), and the resulting milled materials do not allow to obtain concrete with high values of early compressive strength at 28 days of age.

The technical task of the invention is the creation of an intensifier grinding, effective when grinding various types of minerals and to improve the performance of mills and improve the characteristics of the crushed materials while reducing energy consumption.

The stated technical problem is solved in the invention by the fact that in the grinding intensifier, based on a mixture of ethanolamines and alkanediols in the following ratio (wt.%): Ethanolamines - 30-60; alkanediols - 40-70, a mixture of ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol is used as alkanediols. In addition, a sulfonate type plasticizer based on a mixture of oligomeric naphthalene sulfonic acid condensation products is added.

The grinding intensifier is obtained by directed synthesis and further mixing of the components in the form of an aqueous solution with a mass fraction of solids of 30% -70%.

The specified range of component ratios is selected experimentally and is optimal.

The content in the composition of the grinding intensifier of less than 30% ethanolamines does not allow to provide the required nature of the grinding, i.e. high mill performance, grinding fineness, fluidity, and strength of concrete obtained on the basis of ground cement clinker using the proposed intensifier. The content in the composition of the intensifier grinding more than 60% of alkanolamines leads to a decrease in the specific surface and fineness of grinding materials.

Accordingly, the content of alkanediols is 40-70%. In this case, the use of a mixture of alkanediols is most effective. The composition of the mixture depends on the technical and technological parameters of the mill. The most effective is the use of a mixture of ethylene glycol, butylene glycol, propylene glycol and polyethylene glycol. The optimal ratio of ethylene glycol, propylene glycol, butylene glycol, which are monoethylene glycols, and polyethylene glycol is (5 ÷ 10) / 1. In this ratio, the polyethylene glycol is completely dissolved in these monoglycols. In this case, chains of various lengths are obtained, which positively affects the efficiency of the grinding process of various types of minerals.

The introduction of a plasticizer during grinding increases the rate of gain of the specific surface of cement due to the Rebinder effect, which consists in an adsorption decrease in the strength of solids.

In more detail, the technical nature of the invention and the achieved effects can be illustrated by the following examples, which do not exhaust all possible options for the grinding intensifier, but help to more clearly demonstrate its properties.

The cement clinker grinding intensifier is prepared by mixing the components in a certain sequence in the form of an aqueous solution.

Example 1

The composition of the sample (wt.%): Triethanolamine - 30; ethylene glycol - 35;

butylene glycol -15, propylene glycol-10, polyethylene glycol-10, sulphonate-type plasticizer - 10. (contained in excess of 100%).

Example 2

The composition of the sample (wt.%): Triethanolamine - 40; ethylene glycol - 35;

butylene glycol -5, propylene glycol-10, polyethylene glycol-10.

Example 3

The composition of the sample (wt.%): Triethanolamine - 60; ethylene glycol - 25;

butylene glycol -5, propylene glycol -5, polyethylene glycol-5;

sulfonate type plasticizer - 10% (contained in excess of 100%).

The presented test results of grinding cement clinker and concrete obtained by using grinding intensifiers can be interpolated to other types of materials, since the patterns obtained during grinding of cement clinker are also characteristic of the other materials under consideration.

The effectiveness of the intensifiers was evaluated by comparing the parameters of the mill and the characteristics of cements and concrete using the intensifier and prototype proposed by the invention. The results are shown in table 1.

Table 1 The name of indicators Cement without intensifier Cement with intensifier prototype according to the invention example 1 example 2 example 3 Average productivity, t / h 41.1 45 46.5 47.1 46.8 Average fuel consumption energy, kW / t of cement 39.6 38 36.5 36.3 36.7 Specific surface cm ² / g 4155 4378 4418 4507 4479 The fineness of grinding cement,% (residue on sieve No. 008) 6.8 5.2 4.4 4.2 4.4 ASTM cement fluidity,% (passage through sieve 05) 47 65 70 71 70 The compressive strength at age, MPa, according to GOST 311082, days 26.5 27 27,2 27.3 27,2 28 days 48.6 49.5 50,2 50,5 50.3

The intensifier was prepared in the form of 40-50% aqueous solutions. The dosage of the intensifier is 0.02%.

During the tests, the performance of the mill was recorded according to the testimony of weight batchers. Evaluation of the effect of intensifiers was carried out by grinding fineness (residue on sieve No. 008), specific surface, compressive strength at 2- and 28-day-old age, determined according to GOST 310.4-81. The fluidity of the cement was also evaluated. It was quantified by ASTM 1565-04. The essence of the technique is to sift the cement sample through a No. 05 sieve on a Hagermann shaking table. Cement has high fluidity if more than 50% of the material passes through a sieve when shaking.

The residue on sieve No. 008 was in the range of 4.9-6.8 mass. % Initially, within 4 hours the mill was brought to a stable mode of operation with an intensifier, then the parameters of the mill were recorded and samples were taken for physicomechanical testing of cements.

The use of the intensifier grinding according to the invention in comparison with the prototype allows to increase the productivity of industrial mills by 3-5% while maintaining the quality of the produced cement. At the same time, energy consumption is reduced by 3.5-4.4%.

The optimal dosage of the intensifier grinding according to the invention ranges from 0.020-0.030 mass. % dry matter. In this interval of its values, there is a maximum increase in mill productivity and an increase in the strength characteristics of cement.

The use of the intensifier grinding according to the invention in comparison with the prototype allows to obtain cement with greater fluidity. So the use of the intensifier according to the invention (for example, example 2) allows to increase this indicator by 4% compared with the use of the intensifier prototype.

The results of comparative tests of concrete based on cements obtained using the grinding intensifier proposed in the invention and using the prototype intensifier showed an improvement in strength characteristics in the case of cement obtained using the grinding intensifier according to the invention. So, at the age of 28 days, concrete-based concrete made with the use of intensifiers according to the invention have a compressive strength of 1.4-2% higher compared to cement-based concrete made with the use of a prototype intensifier. There is also a slight increase in the early strength of concrete. At the age of 2 days, the strength of concrete on cement obtained using the grinding intensifier according to the invention is 0.4-1% higher than when using the prototype additive.

Thus, the proposed grinding intensifier is effective in grinding various types of materials and can improve the performance of mills and improve the characteristics of the crushed materials while reducing energy consumption.

Claims (2)

1. The intensifier grinding based on a mixture of ethanolamines and alkanediols containing these components in the following ratio (wt.%):
ethanolamines - 30-60, alkanediols - 40-70,
however, ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol are used as alkanediols, characterized in that a mixture of these compounds is used as alkanediols. 2. The grinding intensifier according to claim 1, characterized in that a sulfonate type plasticizer based on a mixture of oligomeric naphthalene sulfonic acid condensation products is further added to it.