RU2304084C2 - Scale inhibition method - Google Patents

Abstract

FIELD: scale prevention methods.

SUBSTANCE: invention relates to methods for preventing deposits of mineral salts and can find use in prevention of scaling on surfaces boilers and equipment in heat and steam supply systems as well as in recycling water supply systems. Method comprises adding organophosphonic acids, salts thereof, or metal complexes of these acids, to water. Indicated acids or their derivatives are added in amounts meeting following scale inhibition limits relationship: ln(Cⁱ ₊C^j _-/P_o) < σ(2ab sin γ + 2 ac sin β + bc sin α)/kTn, where C₊ represents concentration of scale forming salt cation in water, mole/dm³; i number of cations in scale forming salt; C_- concentration of scale forming salt anion in water, mole/dm³; j number of anions in scale forming salt; Po product of solubility of scale forming salt; σ free energy of water/salt interface for scale forming salt, J/m³; a, b, c are lengths of ribs of the cell in crystalline lattice of scale forming salt, m; α, β, γ are angles between ribs of the cell in crystalline lattice of scale forming salt; k is Boltzmann constant, k = 1.38·10^-23 J/K; T absolute temperature, K; and n number of formula units of scale forming salt in one cell of crystal lattice.

EFFECT: reduced process risks associated with scaling of equipment surfaces.

10 cl, 2 dwg, 2 tbl

Description

Technical field

The invention relates to methods for preventing the deposition of mineral salts and can be used, for example, to protect against the formation of scale surfaces of boilers, boiler auxiliary equipment and devices of consumers of thermal energy in heat and steam supply systems in industry, energy and utilities, as well as for protection from scale formation of circulating water supply systems.

State of the art

Known metal ion complexes for use as scale inhibitors [1]. The complexes consist of phosphonic acids and transition metal ions, in particular copper, as well as nickel, cobalt, and zinc additives. These complexes prevent scaling only in a narrow range of conditions and have a limited scope.

A known method of inhibiting scale formation and corrosion by sulfonated organophosphonates [2]. The method is designed to inhibit or prevent the formation of sediment on surfaces in contact with water having a hydrogen ion concentration index (pH) of at least 7.5. The method includes adding sulfonated organophosphonates to water in a known concentration range. The disadvantage of this method is the limited scope, due to the lack of control of the content of ions in water involved in the formation of scaling.

A known method of preventing alkaline scale formation [3], which consists in the fact that scale inhibitor is introduced into acidified water after its decarbonization. The disadvantage of this method is the lack of effectiveness, since when preparing water for the introduction of a scale inhibitor, the content in the water, in addition to the ions that are destroyed and removed by acidification and decarbonization, other ions that are part of the scale deposits are not taken into account.

The closest to the claimed invention in terms of technical nature and the achieved positive effect is a method for maintaining a complex water-chemical regime of low-energy thermal energy systems using organophosphonic acids produced by the domestic industry, for example, hydroxyethylidene diphosphonic or nitrilotrimethylphosphonic acid, or salts of these acids, or complexes of these acids with metals [4, pages 65 to 97]. The method includes monitoring indicators of the ionic composition of water, for example, hardness (the sum of the concentration of calcium ions and the concentration of magnesium ions) or a carbonate index (the product of the concentration of calcium ions and the total alkalinity of water) and the subsequent introduction of organophosphonic acids, their salts or complexes into water, in a known amount specified acids with metals. The disadvantage of this method is the lack of effectiveness, since when preparing water for the introduction of organophosphonic acids or their derivatives, the concentration of certain ions in water is taken into account, but the concentration of salt ions in the water, which forms deposits, in addition to calcium and magnesium, as well as the total effect of ions on alkalinity of water. As a result of this, there are frequent cases when, subject to the conditions recommended in the source [4], it is not possible to achieve effective braking or to prevent the formation of scaling.

Disclosure of invention

The aim of the invention is to increase the efficiency and reliability of the inhibition of scaling.

The technical result that is achieved by using the proposed method is to reliably prevent the formation of scaling when using organophosphonic acids or their derivatives as an inhibitor, and to reduce technological risks associated with the formation of scaling on the surfaces of technological equipment.

The technical result is achieved by the fact that the method of inhibiting scaling involves introducing organophosphonic acids, salts of these acids, or complexes of these acids with metals into water, and organophosphonic acids or their derivatives are introduced if the ratio of the scale of inhibition of scaling is satisfied

,

,

where C ₊ is the concentration in water of the cation of salt, forming deposits, mol / DM ³ ;

i is the number of cations in the salt formula;

With _{- the} concentration in water of the salt anion, forming a deposit, mol / DM ³ ;

j is the number of anions in the salt formula;

P ₀ is the solubility product of the salt forming the deposit;

σ is the free energy of the interface between water and salt, forming deposits, J / m ² ;

a, b, c - the lengths of the edges of the cell of the crystal lattice of salt, forming deposits, m;

α, β, γ are the angles between the edges of the cell of the crystal lattice of salt, forming deposits;

k is the Boltzmann constant, k = 1.38 · 10 ^-23 J / K;

T is the absolute temperature, K;

n is the number of formula units of salt forming a deposit in one cell of the crystal lattice.

That takes into account the concentration in water of salt ions that form the scale, and organophosphonic acids or their derivatives are introduced if the ratio of the scale of inhibition of scale

,

,

is new compared to the prototype. Due to the new set of essential features of the proposed method, a technical result is achieved.

(моль/дм³)², где С_Ca - концентрация ионов кальция, моль/дм³;

- концентрация карбонат-ионов, моль/дм³. По сравнению с прототипом то, что учитывают концентрации в воде ионов кальция и карбонат-ионов, а также используют соотношение

(моль/дм³)², является новым.In the particular case of the implementation of the claimed invention for the inhibition of scaling of calcium carbonate, organophosphonic acids or their derivatives are administered if the ratio of the scale of inhibition of scaling is met

(mol / dm ³ ) ² , where C _Ca is the concentration of calcium ions, mol / dm ³ ;

- concentration of carbonate ions, mol / dm ³ . Compared with the prototype, that takes into account the concentration in the water of calcium ions and carbonate ions, and also use the ratio

(mol / dm ³ ) ² , is new.

(моль/дм³)², где С_Ca - концентрация ионов кальция, моль/дм³;

- концентрация сульфат-ионов, моль/дм³. По сравнению с прототипом то, что учитывают концентрации в воде ионов кальция и сульфат-ионов, а также используют соотношение

(моль/дм³)², является новым.In the particular case of the implementation of the claimed invention to inhibit scaling of calcium sulfate, organophosphonic acids or their derivatives are administered if the ratio of the scale of inhibition of scaling is met

(mol / dm ³ ) ² , where C _Ca is the concentration of calcium ions, mol / dm ³ ;

- concentration of sulfate ions, mol / dm ³ . Compared with the prototype, that takes into account the concentration in the water of calcium ions and sulfate ions, and also use the ratio

(mol / dm ³ ) ² , is new.

In the particular case of the invention, the concentration of salt ions in the water forming the deposits is controlled by the titrimetric, electrochemical or photocolorimetric method before the administration of organophosphonic acids or their derivatives. This is new compared to the prototype.

In the particular case of the invention, the concentration of salt ions in the water forming the deposits is controlled by the titrimetric, electrochemical or photocolorimetric method in the process of introducing organophosphonic acids or their derivatives periodically. This is new compared to the prototype.

In the particular case of the implementation of the claimed invention, before the introduction of organophosphonic acids or their derivatives, the water is additionally treated to reduce the concentration of at least one of the salt ions that form the deposits, until the ratio of the scale of inhibition of scaling is satisfied. This is new compared to the prototype.

In the particular case of the invention, the additional water treatment is carried out by ion exchange. This is new compared to the prototype.

In the particular case of the invention, the additional water treatment is carried out by acidification of water. This is new compared to the prototype.

In the particular case of the invention, the additional water treatment is carried out by decarbonization of water. This is new compared to the prototype.

Brief Description of the Drawings

Figure 1 schematically depicts a fragment of a growing salt crystal, forming a deposit, with particles of organophosphonic acids or their derivatives on its surface. The following notation is used:

1 - a growing salt crystal;

2 - stages of crystal growth;

3 - particles of organophosphonic acids or their derivatives, preventing the movement of the growth stage.

Figure 2 schematically shows the smallest seed crystal of salt forming a deposit, on the surface of which a particle of organophosphonic acid or a derivative of such an acid can still impede the movement of the growth stage. The following notation is used:

1 - possible position of the moving growth stage;

2 - possible position of the inhibitor particle on the surface;

a, b, c are the lengths of the edges of the cell of the crystal lattice;

α, β, γ are the angles between the edges of the cell of the crystal lattice;

V is the volume of the embryo;

S is the surface of the embryo.

The implementation of the invention

The possibility of carrying out the claimed invention is confirmed by the following theoretical premises and examples of practical implementation.

The process of scaling includes two stages: the formation of salt crystal nuclei and further crystal growth due to the sequential buildup of salt cells of the crystal lattice adjacent to the growth steps on the surface of the crystal with formula units of salt. The inventive method of inhibiting scaling, schematically shown in figure 1, is based on the fact that on crystal 1, on the surface of which there are growth steps 2, particles of inhibitor 3 (organophosphonic acids, salts of these acids, or complexes of these acids with metals are adsorbed) ), which prevent the building up of the cells of the crystal lattice adjacent to the steps of growth. Due to this, the growth of a salt crystal is impossible. If, as a result of the blocking of the motion of the growth steps, the growth process of the crystal nucleus stops before the nucleus enlarges to the sizes ensuring its stability, the nucleus remains unstable and collapses. In this case, the introduction into water of organophosphonic acids, salts of these acids or complexes of these acids with metals leads to inhibition of scaling.

Therefore, the method of inhibiting scaling, including the introduction of organophosphonic acids, salts of these acids, or complexes of these acids with metals into water, is effective only when the smallest seed crystal of salt forms deposits, on the surface of which the inhibitor particle can still inhibit the movement of the step growth, is in unstable equilibrium with a solution. The geometric shape and dimensions of such a nucleus, consisting of two cells of the crystal lattice, are shown schematically in figure 2. Such a nucleus will be in unstable equilibrium with a solution if, upon its formation, the change in the isobaric-isothermal potential (Gibbs free energy) ΔG is positive [5]. The value of ΔG is given by the formula

where S is the surface of the embryo;

σ is the free energy of the interface between water and salt, J / m ² ;

N is the number of formula units of salt in the embryo;

Δμ is the difference in chemical potentials of the salt forming the deposit in the solution and in the crystal lattice.

As can be seen from the geometric construction in figure 2, the surface of the nucleus is

where a, b, c are the lengths of the edges of the cell of the crystal lattice, m;

α, β, γ are the angles between the edges of the cell of the crystal lattice.

The number of formula units of salt in the embryo

where n is the number of formula units of salt forming a deposit in one cell of the crystal lattice.

The difference in chemical potentials of the salt forming the deposit in the solution and in the crystal lattice Δμ is given by the formula

where k is the Boltzmann constant, k = 1.38 · 10 ^-23 J / K;

T is the absolute temperature, K;

С ₊ - concentration of salt cation in water, mol / dm ³ ;

i is the number of cations in the salt formula;

C _- is the concentration of salt anion in water, mol / dm ³ ;

j is the number of anions in the salt formula;

P ₀ is the product of the solubility of the salt.

Having considered the condition ΔG> 0 and substituting formulas (2), (3) and (4) into formula (1), we obtain

where, finally,

Relation (5) is the ratio of the scale of inhibition of scaling. When fulfilling the ratio of the boundaries of inhibition of scaling, the salt germ, schematically shown in figure 2, will be in unstable equilibrium with the solution. When organophosphonic acids, salts of these acids, or complexes of these acids with metals are introduced into water, the embryo growth process will be blocked. Consequently, the embryo cannot be enlarged and, due to unstable equilibrium with the solution, will collapse.

Thus, a method of inhibiting scaling, including the introduction of organophosphonic acids, salts of these acids or complexes of these acids with metals into water, and these acids or their derivatives are introduced if the ratio of the scale of inhibition of scaling is met, provides reliable prevention of scaling and reduction of technological risks associated with with the formation of scaling on the surfaces of technological equipment.

(моль/дм³)². В примерах практического осуществления в воду вводили оксиэтилидендифосфоновую кислоту по ТУ 2439-363-05763441-2002, хлорид кальция (гексагидрат) по ТУ 6-09-3834-80, и карбонат натрия по ГОСТ 83-79. Исходные концентрации компонентов в различных примерах приведены в табл.1. Эффективность ингибирования определяли по формуле:The possibility of carrying out the claimed invention for inhibiting scaling of calcium carbonate is confirmed by calculation and examples of practical implementation. When water is supersaturated with calcium carbonate, it crystallizes most often in the form of calcite. The calcium carbonate formula includes one cation (i = 1) and one anion (j = 1). The solubility product of calcium carbonate in the form of calcite, according to [6], is P ₀ = 4.8 · 10 ^-9 (mol / dm ³ ) ² at an absolute temperature of T = 300 K. Free energy of the interface between water and calcite, according to [7], is σ = 8 · 10 ^-2 J / m ² . The lengths of the edges of the cell of the calcite crystal lattice considered in the rhombohedral (Miller) setup, according to [8], are a = b = c = 6.37 · 10 ^-10 m, the angles between the edges are α = β = γ = 46 ° 05 ' (the relations a = b = c and α = β = γ follow from the presence of a third-order symmetry axis), and the number of formula units of calcium carbonate in one cell of the calcite crystal lattice is n = 2 (two calcium atoms Ca, two carbon atoms C, six oxygen atoms O). (Information from the source [8] is available on the Internet at http://students.web.ru/db/msg.html?mid=1163834&uri=11-2-3.htm). Substituting these data in relation (5), we obtain:

(mol / dm ³ ) ² . In practical examples, hydroxyethylidene diphosphonic acid was introduced into water according to TU 2439-363-05763441-2002, calcium chloride (hexahydrate) according to TU 6-09-3834-80, and sodium carbonate according to GOST 83-79. The initial concentrations of the components in the various examples are given in table 1. The effectiveness of inhibition was determined by the formula:

- установившаяся концентрация ионов кальция после выпадения осадка, моль/дм³;Where

- steady-state concentration of calcium ions after precipitation, mol / dm ³ ;

- установившаяся концентрация ионов кальция после выпадения осадка в контрольном опыте (без добавления оксиэтилиденди-фосфоновой кислоты), моль/дм³.

- the steady-state concentration of calcium ions after precipitation in the control experiment (without the addition of hydroxyethylidene diphosphonic acid), mol / dm ³ .

(моль/дм³)² выполнено, эффективность ингибирования солеотложений достаточно высока для практического использования данного способа (не менее 85%). В примерах 4 и 5, в которых рассматриваемое соотношение не выполнено, эффективность ингибирования оказывается недопустимо низкой (не более 24%), даже несмотря на то, что концентрация оксиэтилиден-дифосфоновой кислоты в этих примерах выше. Таким образом, способ ингибирования солеотложений карбоната кальция, включающий введение в воду органофосфоновых кислот или их производных, причем указанные кислоты или их производные вводят, если выполняется соотношение

(моль/дм³)², обеспечивает надежное предотвращение образования солеотложений и снижение технологических рисков, связанных с образованием солеотложений на поверхностях технологического оборудования.From table 1 it can be seen that in examples 1-3, in which the ratio

(mol / dm ³ ) ^{2 is} performed, the efficiency of inhibition of scaling is high enough for the practical use of this method (at least 85%). In examples 4 and 5, in which the ratio is not satisfied, the inhibition efficiency is unacceptably low (not more than 24%), even though the concentration of hydroxyethylidene diphosphonic acid in these examples is higher. Thus, a method of inhibiting scaling of calcium carbonate, comprising introducing organophosphonic acids or their derivatives into water, said acids or their derivatives being introduced if the ratio

(mol / dm ³ ) ² , provides reliable prevention of scaling and reduction of technological risks associated with the formation of scaling on the surfaces of technological equipment.

(моль/дм³)². В примерах практического осуществления в воду вводили нитрилотриметилфосфоновую кислоту по ТУ 2439-347-05763441-2001, хлорид кальция (гексагидрат) по ТУ 6-09-3834-80, и сульфат натрия по ГОСТ 6318-77. Исходные концентрации компонентов в различных примерах приведены в табл.2. Эффективность ингибирования определяли по формуле (6).The possibility of carrying out the claimed invention for inhibiting scaling of calcium sulfate is also confirmed by calculation and examples of practical implementation. When water is supersaturated with calcium sulfate, it crystallizes most often in the form of gypsum. The solubility product of calcium sulfate in the form of gypsum, according to [6], is P ₀ = 2.5 · 10 ^-5 (mol / dm ³ ) ² at an absolute temperature of T = 300 K. Free energy of the interface of water and gypsum, according to [7], is α = 2.6 · 10 ^-2 J / m ² . The lengths of the edges of the cell of the gypsum crystal lattice, according to the MINCRYST information-computing system [9], are a = 5.68 · 10 ^-10 m, b = 15.2 · 10 ^-10 m, s = 6.52 · 10 ^-10 m. The angles between the edges of the cell of the crystal lattice are α = γ = 90 °, β = 118 °. The number of formula units of calcium sulfate in one cell of the gypsum crystal lattice is n = 4. (Information from the MINCRYST computer system is available on the Internet at http://database.iem.ac.ru/mincryst/eng/s_carta.php?GYPSUM+1828). Substituting these data in relation (5), we obtain:

(mol / dm ³ ) ² . In practical examples, nitrilotrimethylphosphonic acid was introduced into water according to TU 2439-347-05763441-2001, calcium chloride (hexahydrate) according to TU 6-09-3834-80, and sodium sulfate according to GOST 6318-77. The initial concentration of the components in various examples are given in table.2. The effectiveness of inhibition was determined by the formula (6).

(моль/дм³)² выполнено, эффективность ингибирования солеотложений достаточно высока для практического использования данного способа (не менее 82%). В примерах 9 и 10, в которых рассматриваемое соотношение не выполнено, эффективность ингибирования оказывается недопустимо низкой (не более 16%), в то время как концентрация нитрилотриметилфосфоновой кислоты в этих примерах выше. Таким образом, способ ингибирования солеотложений сульфата кальция, включающий введение в воду органофосфоновых кислот или их производных, причем указанные кислоты или их производные вводят, если выполняется соотношение

(моль/дм³)², обеспечивает надежное предотвращение образования солеотложений и снижение технологических рисков, связанных с образованием солеотложений на поверхностях технологического оборудования.From table 2 it is seen that in examples 6-8, in which the ratio

(mol / dm ³ ) ² performed, the effectiveness of the inhibition of scaling is high enough for the practical use of this method (at least 82%). In examples 9 and 10, in which the ratio in question is not satisfied, the inhibition efficiency is unacceptably low (no more than 16%), while the concentration of nitrilotrimethylphosphonic acid in these examples is higher. Thus, a method of inhibiting scaling of calcium sulfate, comprising introducing organophosphonic acids or their derivatives into water, said acids or their derivatives being introduced if the ratio

(mol / dm ³ ) ² , provides reliable prevention of scaling and reduction of technological risks associated with the formation of scaling on the surfaces of technological equipment.

To perform the operation of monitoring the concentration of salt ions in the water forming a deposit, any method known from chemistry can be used to determine the concentration of specific ions, for example, titrimetric, electrochemical, photocolorimetric, or another method.

The control of water concentrations of salt ions forming a deposit may precede the introduction of organophosphonic acids or their derivatives into water.

The control of the concentration of salt ions in the water, forming deposits, can also be carried out in the process of introducing organophosphonic acids or their derivatives periodically.

If the ratio of the boundary of inhibition of scaling is not fulfilled, then, as shown above, the introduction of organophosphonic acids or their derivatives into water will not provide reliable prevention of scaling.

In this case, before the introduction of organophosphonic acids or their derivatives, the water is subjected to additional processing by a method that leads to a decrease in the concentration in water of at least one of the salt ions that form deposits, until this ratio is fulfilled. As a method leading to a decrease in the concentration in water of at least one of the salt ions forming a deposit, any method of water treatment known from the water treatment technology can be used.

In the particular case when calcium or magnesium ions are included in the salt of the deposition salt, a method of ion exchange, and more specifically, a method of cationic water (for example, H-cation or Na cation on universal cation exchanger KU-2-8 according to GOST 20298-74). If sulfate ions are included in the salt forming the sediment, then as a method leading to a decrease in the concentration of these ions, another variant of the ion exchange method can be used - the method of anionizing water, for example, on weakly basic anion exchange resin AN-2F or AN-31 according to GOST 20301-74.

In the particular case, when the composition of the salt forming the deposits includes hydroxide ions, as a method leading to a decrease in the concentration of these ions, a method of acidifying water, for example, phosphoric acid H ₃ PO ₄ , can be used according to the reaction:

H ₃ PO ₄ + 3 OH ^- → 3H ₂ O + PO ₄ ^3- .

In the particular case, when the composition of the salt forming the deposits includes carbonate ions, as a method leading to a decrease in the concentration of these ions, a method of decarbonization of water by the reaction can be used:

СО ₃ ^2- + 2Н ⁺ → Н ₂ О + СО ₂ ↑.

Industrial applicability

The proposed method of inhibiting scaling is simple and affordable. All operations included in its composition (introduction of oxyethylidene diphosphonic acid, nitrilotrimethylphosphonic acid, salts of these acids, or complexes of these acids with metals, as well as control of the concentration of salt ions forming deposits) are simple and can be carried out in a known manner using standard equipment. The method is effective and can be used, for example, to protect against the formation of scale surfaces of boilers, boiler auxiliary equipment and devices of consumers of thermal energy in heat and steam supply systems in industry, energy and utilities, as well as to protect against scale formation of circulating water systems .

Table 1 Example No. The concentration of inhibitor (OEDP acid), mg / DM ³ The concentration of ions of salt, forming deposits, mol / DM ³

The value of the product of concentrations

Absolute temperature T, K Fulfillment of the condition

(mol / dm ³ ) ² Scale Inhibition Efficiency,% Calcium ions
With _Ca Carbonate ions

one twenty 3.0 · 10 ^-2 0.16 4.8 · 10 ^-3 300 Done 98 2 twenty 0.10 4.0 · 10 ^-2 4.0 · 10 ^-3 300 Done 99 3 thirty 8.0 · 10 ^-2 8.0 · 10 ^-2 6.4 · 10 ^-3 300 Done 85 four 36 0.12 0.12 1.4 · 10 ^-2 300 Not done 24 5 40 0.15 0.16 2.4 · 10 ^-2 300 Not done 12

table 2 Example No.
The concentration of inhibitor (NTP acid), mg / DM ³
The concentration of ions of salt, forming deposits, mol / DM ³

 The value of the product of concentrations

Absolute temperature T, K
Fulfillment of the condition

(mol / dm ³ ) ²
Scale Inhibition Efficiency,%
Calcium ions
C _ca Sulfate ions

6 thirty 0.1 4.0 · 10 ^-2 4.0 · 10 ^-3 300 Done 92 7 thirty 3.0 · 10 ^-2 0.15 4,5 · 10 ^-3 300 Done 84 8 thirty 6.5 · 10 ^-2 6.5 · 10 ^-2 4.2 · 10 ^-3 300 Done 82 9 40 8.0 · 10 ^-2 8.0 · 10 ^-2 6.4 · 10 ^-2 300 Not done 16 10 40 0.1 0.1 1,0 · 10 ^-2 300 Not done 10

Information sources

1. US patent 5057228. Complexes of metal ions for use as scale inhibitors / P.J. Breen, H. H. Downs, B. N. Diel. - IPC С02F 5/14, publ. 10/15/1991.

2. US patent 5221487. Inhibition of scale formation and corrosion sulfonated organophosphonates / Ch.G. Carter - IPC C02F 5/14, publ. 06/22/1993.

3. RF application 93037800. A method for preventing alkaline scale formation / O.D. Linnikov, V. P. Podberezny, E. A. Anokhina. - IPC С02F 5/08, publ. 01/20/1996.

4. Chausov F.F., Raevskaya G.A. Complex water-chemical regime of low-energy heat power systems. A practical guide. Moscow - Izhevsk: Research Center "Regular and chaotic dynamics", 2003. - 280 p.

5. Landau L.D., Lifshits E.M. Theoretical physics. T.5. Statistical Physics. - M .: Nauka, 1976 .-- 584 p.

6. Lurie Y. Yu. Handbook of analytical chemistry. M .: Goskhimizdat, 1962. - P.76-79.

7. Lasaga A.S. Kinetic theory in the Earth sciences. Princeton, 1998 .-- P.499.

8. Egorov-Tismenko Yu.K., Litvinskaya G.P. Theory of crystal symmetry. Scientific Editor - Corr. RAS, professor V.S. Urusov. Textbook for higher education - M. GEOS, 2000, 410 p. (Internet access is available at http://students.web.ru/db/msg.html?mid=1163834&uri=index.htm).

9. Chichegov A.V. and other Information-computing system according to the crystal structure of minerals (MINCRYST) // Crystallography, T.35, No. 3, 1990. - S.610-616. (Access to the information and computing system on the Internet at http://database.iem.ac.ru/mincryst/).

Claims (9)

1. A method of inhibiting scaling, including the introduction into water of organophosphonic acids, salts of these acids or complexes of these acids with metals, characterized in that organophosphonic acids or their derivatives are introduced if the ratio of the boundary of inhibition of scaling

where C ₊ is the concentration in water of the cation of salt, forming deposits, mol / DM ³ ; i is the number of cations in the salt formula; With _{- the} concentration in water of the salt anion, forming a deposit, mol / DM ³ ; j is the number of anions in the salt formula; P ₀ is the solubility product of the salt forming the deposits; σ is the free energy of the interface between water and salt, forming deposits, J / m ² ; a, b, c - the lengths of the edges of the cell of the crystal lattice of salt, forming deposits, m; α, β, γ are the angles between the edges of the cell of the crystal lattice of salt, forming deposits; k is the Boltzmann constant, k = 1.38 · 10 ^-23 J / K; T is the absolute temperature, K; n is the number of formula units of salt forming a deposit in one cell of the crystal lattice. 2. The method according to claim 1, characterized in that organophosphonic acids or their derivatives are administered if the ratio of the scale of inhibition of scaling is met

(mol / dm ³ ) ² , where C _Ca is the concentration of calcium ions, mol / dm ³ ;

- concentration of carbonate ions, mol / dm ³ . 3. The method according to claim 1, characterized in that the organophosphonic acids or their derivatives are administered if the ratio of the scale of inhibition of scaling is met

(mol / dm ³ ) ² , where C _Ca is the concentration of calcium ions, mol / dm ³ ;

- concentration of sulfate ions, mol / dm ³ . 4. The method according to any one of claims 1, 2 or 3, characterized in that the concentration of salt ions in the water forming the deposits is controlled by the titrimetric, electrochemical or photocolorimetric method before the administration of organophosphonic acids or their derivatives. 5. The method according to any one of claims 1, 2 or 3, characterized in that the concentration of salt ions in the water forming the deposits is controlled by the titrimetric, electrochemical or photocolorimetric method in the process of introducing organophosphonic acids or their derivatives periodically. 6. The method according to any one of claims 1, 2 or 3, characterized in that before the introduction of organophosphonic acids or their derivatives, water is additionally treated to reduce the concentration of at least one of the salt ions that form the deposits, until the ratio of the scale of inhibition of scaling will be fulfilled. 7. The method according to claim 6, characterized in that the additional water treatment is carried out by ion exchange. 9. The method according to claim 6, characterized in that the additional water treatment is carried out by acidification of water. 10. The method according to claim 6, characterized in that the additional water treatment is carried out by decarbonization of water.

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