RU2452748C1 - Method to produce sulphur bitumen - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method includes mixing melted bitumen, sulphur and an activating additive in process of heating. To activate a reaction mixture, amines are used in the amount of 0.3-3.0 wt %, in respect to sulphur. Reaction is carried out at 130-150°C for 2-3 hours. Mass ratio of sulphur and bitumen makes 20-70:30-80. The proposed method is ecologically safer, makes it possible to cheapen the target product by addition of a considerable amount of sulphur, to solve the problem of recycling sulphur being a by-product of oil production and oil processing. In process of further manufacturing of sulphur asphalt concrete, any mineral fillers may be used, included contaminated ones, this will not affect the quality of the target product. The produced sulphur concrete has higher strength, better adhesion to mineral fillers, demonstrates high frost resistance.

EFFECT: improved operational characteristics.

8 cl, 3 tbl, 21 ex

Description

The invention relates to construction, and in particular to methods for producing road-building materials - sulfur bitumen for the production of sulfur-asphalt concrete.

The prospects for the production of sulfur bitumen and their use in road construction is due to the following circumstances. Firstly, the vastness of the raw material base in the form of technical sulfur and sulfur-containing waste. Over the past decade, in all industrialized countries, including Russia, there has been an increase in the production of industrial sulfur, primarily as a by-product in the processing and refining of natural and flue gas oil. Sulfur-containing waste is dumped. According to some reports, 5 million tons of sulfur are produced annually in Russia, more than 300,000 tons in the Republic of Tatarstan alone. The introduction of sulfur can significantly reduce the cost of bitumen, the price of which due to the energy crisis has increased significantly. Reducing the content of bitumen in sulfur bitumen due to the addition of cheaper and available in significant quantities of sulfur reduces the cost of paving. So, even a slight addition of sulfur (up to 3 wt.% Per bitumen emulsion) can reduce the cost by 4-5%. Expanding the application of sulfur and sulfur-containing waste is an urgent task both from an economic and environmental point of view. Taking into account that construction is one of the leading and material-intensive sectors of the national economy, the use of sulfur and sulfur-containing wastes in the technology of the Russian construction industry is a promising and economically attractive direction.

Secondly, the use of sulfur bitumens in the construction and repair of the roadway makes it possible to widely use not crushed stone in road construction, but cheap inert materials (sandy soils, weak stone materials, ashes and slags), the use of which in combination with ordinary bitumen is impossible, which also provides significant economic effect.

The main reason is a significant improvement in the properties of asphalt mixtures based on sulfur bitumen: higher compressive strength, which makes it possible to reduce the thickness of the corresponding layers of road surfaces; higher heat resistance without a significant increase in stiffness at low temperatures, which reduces the risk of cracking in the layers of road surfaces in winter and plastic deformations in the summer; the preparation of mixtures based on sulfur bitumen at lower heating temperatures of the components; higher resistance of sulfur-bitumen materials to dynamic loads; higher resistance to the effects of organic solvents and aggressive environments, which allows them to be used when coating on parking lots, service stations, hydraulic structures.

Thus, the problem of establishing production of sulfur bitumen in Russia is very relevant. However, this problem has not yet been solved, since the known methods for the production of sulfur-bitumen offer either insignificant addition of sulfur (up to 10% with respect to bitumen) or do not allow achieving high physical and mechanical properties of sulfur-bitumen, in particular adhesion, softening temperature, frost resistance (temperature fragility) in accordance with the requirements of GOST 22245-90. As shown earlier, an increase in the amount of sulfur in bitumen raw materials to 10% leads to a decrease in ductility, the resulting bitumen does not meet the requirements of the standard [I.R. Telyashev. The study of the laws of the process of interaction of heavy oil residues with elemental sulfur. Abstract. diss. for the degree of candidate of technical sciences, 2002, p.20].

Most methods for producing sulfur-bitumen are based on the activation of the reaction mixture with its further mixing with bitumen. Activation of the reaction mixture is carried out in various ways, for example, cavitation-acoustic exposure or exposure to an electromagnetic field.

So, there is a method of producing serobitum [RU 2223992 C2, publ. 2003.10.10], including preheating bitumen to 125-170 ° C, activating it by cavitation-acoustic exposure, modifying sulfur by introducing 0.5-10.0 wt.% Of the weight of sulfur of activated bitumen into it and performing cavitation-acoustic exposure for 5-15 minutes at 125-170 ° C, mixing by cavitation-acoustic exposure to modified sulfur and activated bitumen in a weight ratio (0.03-1): 1 with a circulation ratio of 3-10. This method allows you to enter in bitumen no more than 10% sulfur.

A method for producing a sulfur-bitumen binder by mixing liquid sulfur and road bitumen in a ratio of 20:80 and 80:20 at a temperature of 130-140 ° C with subsequent exposure to the components to be mixed with a powerful electromagnetic field is described [RU 2159218, 20.11.2000]. The disadvantage of the method, despite obtaining sulfur bitumen with a high sulfur content, is the need to use complex equipment in the form of a vortex layer apparatus equipped with ferromagnetic elements rotating in a powerful electromagnetic field, and the inability to achieve high physical and mechanical properties of the binder and, in particular, adhesion, temperature softening, frost resistance (fragility temperature) in accordance with the requirements of GOST 22245-90.

Another possibility of activating the reaction mixture in the process of producing sulfur bitumen is a chemical effect.

So, sulfur-bitumen binders for asphalt concrete are known, including bitumen and sulfur, which is a modifier of the properties of asphalts and resins, as well as a filler of bituminous masses [SU 1270140 A1, publ. 11/15/1986, SU 1474133 A1, publ. 04/23/1989]. These binders have a low softening and ductility temperature, and asphalt concrete prepared on their basis, as a result, have insufficiently high strength.

A method for producing serobitumen is described, including the modification of sulfur with dicyclopentadiene and the mixing of sulfur with bitumen [RU 2163610, publ. 02/27/2001]. The disadvantage of this method is the high energy consumption due to the length of the mixing process and the use of an expensive modifier.

In the method for producing a sulfur-bitumen binder [RU 2255066 C1, 06.27.2005] by combining melts of pre-modified sulfur and bitumen, sulfur is preliminarily associated with a mixture of unsaturated fatty acids - flotogudron in the ratios sulfur: flotogudron, wt.%: (30:70) - (60 : 40) to obtain organic polysulfides and combine the indicated melts in the following ratio of components, wt.%: Pre-modified sulfur - organic polysulfides - 20-80, bitumen - 20-80. The disadvantage of this method is the multi-stage process and the use of an expensive modifier in significant quantities.

As a prototype, the applicant considers a method for producing a sulfur-bitumen binder [RU 2284304 C2, 09/27/2006], including mixing the components - molten bitumen and sulfur when heated at a temperature of 140-180 ° C, and 1-5 wt.% Styrene is previously added to the molten bitumen -dicyclopentadiene-indene resin or alkadiene-styrene-dicyclopentadiene-indene resin and 1-5 wt.% high molecular weight hydrocarbons - alpha-olefins of fractional composition C ₂₀ -C ₂₆ with a melting point 38-40 ° C and / or industrial oil - petroleum oil with elm awn 5-50 mm ² / s at 50 ° C and stirred for 0.5 h, then added in portions in a weight ratio of sulfur to bitumen 10-50: 90-50, respectively, and stirred for another 2 h. The disadvantages of this method include the introduction of no more than 50 wt.% Sulfur into bitumen, as well as the high cost of the activators used and the complexity of the multi-stage process. In the examples illustrating this invention, the use of expensive bitumen is indicated - BND 90/130 and BNN 80/120. In addition, it should be noted that at the upper temperature limits specified in the description of the patent, there is a strong release of hydrogen sulfide, which makes this method unacceptable for environmental reasons.

An object of the invention is the creation of a new economical method for producing sulfur-bitumen (sulfur-bitumen binder), expanding the arsenal of known methods for producing sulfur-bitumen, with a significant sulfur content (20-70 wt.%), With high physical and mechanical parameters of sulfur-bitumen, corresponding to the requirements of GOST 22245-90, and allowing on its basis to obtain high-quality sulfur-asphalt concrete with improved performance characteristics.

The technical result of the claimed invention is the activation of sulfur in the process of producing sulfur bitumen by a catalyst, which is used as amines, as a result of which the energy-stable and therefore inactive eight-membered sulfur ring at S ₂ and S _{4 is} destroyed, which allows sulfur to actively interact with bitumen.

The technical result is achieved by the claimed method of producing sulfur bitumen based on molten bitumen and sulfur, as well as an activating additive, including mixing the components when heated, and for activation, a catalyst is added to the reaction mixture, which amines are used in an amount of 0.3-3.0 wt. % with respect to sulfur, the reaction is carried out at a temperature of 130-150 ° C for 2-3 hours, and the mass ratio of sulfur to bitumen is 20-70: 30-80.

As a catalyst, primary, secondary or tertiary amines are used, including cyclic and aromatic amines, as well as mixtures thereof. The addition of the catalyst from the above in a mass ratio of 0.3-3.0% with respect to sulfur leads to the chemical activation of sulfur - the energy-stable and therefore inactive eight-membered sulfur ring at S ₂ and S ₄ is destroyed, which allows sulfur to actively interact with the components of bitumen. Adding a catalyst of less than 0.3 wt.% With respect to sulfur does not allow to achieve the claimed technical result, and more than 3% is impractical.

The production of sulfur bitumen by mixing the activated reaction mixture from sulfur and bitumen at a temperature of 130-150 ° C provides the chemical interaction between sulfur and the components of bitumen, forming a homogeneous mixture, which acquires the ability to maintain a stable state for a long time. This method allows you to enter in serobitum from 20 to 70 wt.% Sulfur, which greatly reduces the cost of the target product.

The temperature regime is selected from the calculation of the required sulfur melting temperature (lower limit) and the threshold temperature for the emission of gaseous sulfur and hydrogen sulfide waste (up to 150 ° C).

The mixing time of the reaction mixture is determined in 2-3 hours - for a shorter time the reaction does not pass completely (precipitation of crystalline sulfur is diagnosed during cooling), and a larger one is not economically feasible.

Activation of sulfur by a catalyst, which uses amines in an amount of 0.3-3.0 wt.% With respect to sulfur, can be carried out by introducing a catalyst into molten sulfur (at a temperature of 130-150 ° C) and further mixing with heated 130-150 ° With bitumen, and the addition of a catalyst to bitumen, followed by mixing with sulfur, as well as introducing the catalyst directly into the reaction mixture. To implement the method, you can use bitumen of any road mark. The reaction mixture is stirred for 2-3 hours at a temperature of 130-150 ° C and mass ratios of sulfur: bitumen = 20: 70-30: 80. The obtained sulfur-bitumen is a mixture of chemical compounds of sulfur and bitumen, which acquires the ability to maintain a stable state under ordinary conditions for a long time, and also has improved physicochemical characteristics.

The invention is illustrated by the following examples of specific performance.

Example 1

Sulfur (GOST 127-93), bitumen grade BND 60-90 GOST 22245-90 are used as initial components.

80 g of bitumen are heated to t 130 ° C in a heated container equipped with a propeller-type mixer, and a mixture of 20 g of sulfur and 0.06 g of catalyst (0.3 wt.% With respect to sulfur) heated to 130 ° C is added, as which use hexylamine (h). Stirred at a temperature of 140-150 ° C for 2 hours.

Example 2

Example 2 is carried out under the conditions of example 1, but 70 g of bitumen and 30 g of sulfur are used, octylamine (h) in the amount of 0.3 g (1 wt.% With respect to sulfur) is used as a catalyst, and the reaction mixture is stirred for 2.5 hours.

Example 3

Example 3 is carried out under the conditions of example 1, but 60 g of bitumen and 40 g of sulfur are used, and dodecylamine (h) is used as a catalyst in an amount of 0.6 g (1.5% with respect to sulfur).

Example 4

Example 4 is carried out under the conditions of example 1, but using 50 g of bitumen and 50 g of sulfur, aniline (h) is used as a catalyst in an amount of 1.0 g (2% with respect to sulfur), and the reaction mixture is stirred for 2, 5 o'clock.

Example 5

Example 5 is carried out under the conditions of example 1, but using 40 g of bitumen and 60 g of sulfur, and 1-aminonaphthalene (h) in the amount of 1.5 g (2.5 wt.% With respect to sulfur) is used as a catalyst.

Example 6

Example 6 is carried out under the conditions of example 1, but using 30 g of bitumen and 70 g of sulfur, 2-aminonaphthalene (h) in the amount of 2.1 g (3 wt.% With respect to sulfur) is used as a catalyst, and the reaction mixture is stirred within 3 hours.

Example 7

Example 7 is carried out under the conditions of example 1, but dihexylamine (h) is used as a catalyst in an amount of 0.6 g (3 wt.% With respect to sulfur).

Example 8

Example 8 is carried out under the conditions of example 2, but the catalyst is added to bitumen, followed by the addition of molten sulfur, and dioctylamine (h) in the amount of 0.45 g (1.5 wt.% With respect to sulfur) is used as a catalyst.

Example 9

Example 9 is carried out under the conditions of example 3, but methyldodecylamine (h) is used as a catalyst in an amount of 0.4 g (1 wt.% With respect to sulfur).

Example 10

Example 10 is carried out under the conditions of example 4, but the catalyst is added directly to the reaction mixture of bitumen and sulfur and methylalanine (h) is used as a catalyst in an amount of 0.25 g (0.5 wt.% With respect to sulfur).

Example 11

Example 11 is carried out under the conditions of example 6, but methylaminonaphthalene (h) is used as a catalyst in an amount of 0.7 g (1 wt.% With respect to sulfur).

Example 12

Example 12 is carried out under the conditions of example 1, but dimethyldodecylamine (h) is used as a catalyst in an amount of 0.2 g (1 wt.% With respect to sulfur).

Example 13

Example 13 is carried out under the conditions of example 4, but cetyldimethylamine (h) is used as a catalyst in an amount of 0.5 g (1 wt.% With respect to sulfur).

Example 14

Example 14 is carried out under the conditions of example 6, but alkylpiperazine (h) is used as a catalyst in an amount of 2.1 g (3 wt.% With respect to sulfur.

Example 15

Example 15 is carried out under the conditions of example 1, but piperazine (a cyclic amine) in an amount of 0.4 g (2 wt.% With respect to sulfur) is used as a catalyst.

Example 16

Example 16 is carried out under the conditions of example 3, but pyrazine (h) is used as a catalyst in an amount of 0.2 g (0.5 wt.% With respect to sulfur).

Example 17

Example 17 is carried out under the conditions of example 5, but as a catalyst, alkyl piperazine (h) is used in an amount of 0.6 g (1 wt.% With respect to sulfur).

Example 18

Example 18 is carried out under the conditions of example 6, but alkyl pyridine (h) is used as a catalyst in an amount of 1.4 g (2 wt.% With respect to sulfur).

Example 19

Example 19 is carried out under the conditions of example 2, but as a catalyst, a mixture of amines in an amount of 0.09 g (0.3 wt.% With respect to sulfur) is used - naphthylamine, dimethyldodoceylamine, dimethylaniline, trimethyleneaniline in a mass ratio of 1: 1: 1: one.

Example 20

Example 20 is carried out under the conditions of example 6, but as a catalyst, a mixture of amines in an amount of 2.1 g (3 wt.% With respect to sulfur) is used — aniline, dimethyldodoceylamine, butylpyridine in a weight ratio of 1: 1: 2.

Example 21

Example 21 is carried out under the conditions of example 4, but using bitumen grade BND 90/130, and as a catalyst, a mixture of amines in an amount of 0.45 g (1.5 wt.% With respect to sulfur) is used - aniline, dimethyldodoceylamine, butyl pyridine in bulk 1: 1: 2 ratio.

The study of the properties of the obtained sulfur bitumen was carried out in accordance with the following standards: needle penetration depth GOST 11501, softening temperature on the ring and ball GOST 11506, fragility temperature according to Fraas, ° С (frost resistance) GOST 11507.

Frost resistance was determined for the bitumen obtained in examples 20 and 21, it was -30 ° C and -35 ° C, respectively, which is an excellent indicator.

Other physico-mechanical properties of sulfur-bitumen obtained by the claimed method are presented in table 1.

As can be seen from the results presented in table 1, the data obtained for the depth of penetration of the needle at 25 ° C and the softening temperature of the ring and ball always correspond to the standard. So, the values of the needle penetration depth at 25 ° С 67-82 lie within the limits specified in the standard (60-90), and the values of the softening temperature along the ring and ball (49-59) also meet the requirements of GOST (not less than 47).

The extensibility of samples with a high sulfur content is always below the standard due to the formation of a colloidal system of sulfur-bitumen polymer-bitumen, however, the formation of these colloidal particles of sulfur-bitumen positively affects the strength of the resulting sulfur-asphalt concrete due to better adhesion to the mineral filler.

Based on the obtained by the present method, sulfur bitumen was produced in the standard way sulfur-asphalt concrete of the following composition, wt.%:

OCG 43.5 ASG 33.5 Dolomite sowing 13.7 Serobitum obtained in example 13 13 9.3

Testing the properties of asphalt concrete was performed according to GOST 12801-98. Physico-mechanical properties of the resulting sulfur-asphalt concrete are shown in table 2.

As the test results show, all indicators are not inferior to the requirements of GOST 9128, and in a number of indicators significantly exceed them. So, the water saturation index equal to 1.5% meets the requirements of the standard (1.5-4), the swelling index in volume is better than that specified in the standard (0.3% against 1%), the compressive strength exceeds the requirements of the standard: 115 against 110 at 0 ° C and 12.5 against 12 at 50 ° C, the coefficient of water resistance is better than specified in GOST: 0.9 against 0.85. The adhesion of bitumen to the mineral part of the asphalt mixture corresponds to No. 1 (full coverage of the sample).

In addition, tests were carried out in accordance with GOST 12801-98 for samples of felling taken from the experimental site from sulfur-asphalt concrete pavement (layer thickness 4.9 cm, 2 years elapsed between the laying of sulfur-asphalt concrete and punching the sample). The results are shown in table 3.

The results shown in table 3 indicate that the physicomechanical parameters of felling of the coating from sulfur-asphalt concrete fully comply with the requirements of GOST 9128-97: water saturation index 2.9 at a rate of 1-4, swelling by volume of 0.18 when the requirements of a standard of 1-0, compressive strength 67.3 and 66.8 at normal> 22 (at 20 ° C) and 25.1 at normal> 12 (at 50 ° C), water resistance coefficient 0.99 for requirements> 0.85, compaction coefficient 1.0 at a norm> 0.98. The compaction coefficient of sulfur-asphalt concrete meets the requirements of SNiP 3.06.03-85.

Thus, a new economical and more environmentally friendly method for producing sulfur bitumen has been proposed, which makes it possible to obtain sulfur bitumen that meets the requirements of the standard and produce sulfur-asphalt concrete with improved physical and mechanical properties on its basis.

The claimed method of producing serobitum has the following advantages:

1) the cost reduction of the target product by 1.5 times by adding a significant amount of sulfur,

2) the method solves the problem of sulfur utilization, which is a by-product of oil production and refining;

3) to obtain sulfur bitumen by the claimed method, you can use road bitumen of any brand;

4) the inventive method is environmentally safer in comparison with the known methods for producing sulfur bitumen, since when observing the temperature regime, the formation of hydrogen sulfide is not observed;

5) the method allows for the subsequent manufacture of sulfur-asphalt concrete to use any mineral fillers, such as ASG, crushed stone, both corresponding to GOST and contaminated, this does not affect the properties of the target product.

The product obtained by the claimed method also has significant advantages: increased strength compared to conventional bitumen, has better adhesion of bitumen to mineral fillers, and exhibits high frost resistance.

Sulfur-asphalt concrete from sulfur bitumen obtained by the claimed method has improved performance characteristics.

Table 1 Physico-mechanical properties of sulfur-bitumen obtained by the claimed method Example No. Bitumen *: Sulfur Ratio Catalyst The amount of catalyst,% relative to sulfur The penetration depth of the needle, mm 0.1 at 25 ° C The softening temperature on the ring and the ball, ° C, not lower Elongation, cm, at least at 25 ° С one 80:20 hexylamine 0.3 70 fifty 52 2 70:30 octylamine 1,0 72 49 43 3 60:40 dodecylamine 1,5 77 56 38 four 50:50 aniline 2.0 79 57 38 5 40:60 1-aminonaphthalene 2.5 79 54 31 6 30:70 2-aminonaphthalene 3.0 78 58 36 7 80:20 dihexylamine 3.0 81 54 55 8 70:30 dioctylamine 1,5 67 51 46 9 60:40 methyldodecylamine 1,0 77 56 34 10 50:50 methylalanine 0.5 80 52 39 eleven 30:70 methylaminonaphthalene 1,0 82 51 38 12 80:20 dimethyldodecylamine 1,0 81 54 55 13 50:50 cetyl dimethidamine 1,0 79 54 45 fourteen 30:70 alkylpiperazine 3.0 78 58 36 fifteen 80:20 piperazine 2.0 76 52 55 16 60:40 pyrazine 0.5 77 54 35 17 40:60 alkylpiperazine 1,0 80 48 42 eighteen 30:70 alkyl pyridine 2.0 79 49 34 19 70:30 naphthylamine, dimethyldodoceylamine, dimethylaniline, trimethyleneaniline in a mass ratio of 1: 1: 1: 1 0.3 67 49 56 twenty 30:70 aniline, dimethyldodoceylamine, butylpyridine in a mass ratio of 1: 1: 2 3.0 95 59 34 Norm in accordance with GOST for BND 60/90 60-90 Not less than 47 Not less than 55 21 50:50 (BND 90/130) aniline, dimethyldodoceylamine, butylpyridine in a mass ratio of 1: 1: 2 1,5 129 40 41 Norm in accordance with GOST for BND 90/130 91-130 No more than 43 Not less than 65 According to the prototype with BND 90/130 90-120 43-48 - * In all examples, except example 21, bitumen grade BND 60/90 is used

table 2 Physico-mechanical properties of sulfur-asphalt concrete from sulfur bitumen obtained by the claimed method The name of indicators GOST 9128 requirements Actual figures Density, g / cm ³ - 2,32 Water saturation,% 1,5-4 1,5 Swelling by volume,% 1,0 0.3 Compressive strength KGS / cm ³ 0 ° C 110 115 50 ° C 12 12.5 Water resistance coefficient 0.85 0.9 Adhesion of bitumen to the mineral part of the asphalt mix No. 1

Table 3 Physico-mechanical properties of sulfur-asphalt concrete (samples-felling) from sulfur bitumen obtained by the claimed method Indicators Water saturation,% Swelling by volume,% The limit of compressive strength, KGS / cm ³ Coefficient R _cyx , 20 ° C R _water , 20 ° C R _{50 ° C} To the _drain. To _seal Reformed samples 2.9 0.18 67.3 66.8 25.1 0.99 1,0 Standard requirements 1-4 0-1 > 22 > 12 > 0.85 > 0.98

Claims (8)

1. A method of producing sulfur-bitumen based on molten bitumen and sulfur, as well as an activating additive, comprising mixing the components by heating, characterized in that amines are used as an activating additive in an amount of 0.3-3.0 wt.% With respect to sulfur, the reaction is carried out at a temperature of 130-150 ° C for 2-3 hours, and the mass ratio of sulfur to bitumen is 20-70: 30-80. 2. The method according to claim 1, characterized in that the primary amines are used as amines. 3. The method according to claim 1, characterized in that secondary amines are used as amines. 4. The method according to claim 1, characterized in that tertiary amines are used as amines. 5. The method according to claim 1, characterized in that the amines are added to the molten sulfur before it is mixed with the molten bitumen. 6. The method according to claim 1, characterized in that the amines are added to the molten bitumen before it is mixed with molten sulfur. 7. The method according to claim 1, characterized in that the amines are added directly to the reaction mixture of sulfur with bitumen. 8. The method according to claim 1, characterized in that use road bitumen of any brand.