DE4409428A1 - Process for the preparation of sulphonated dispersing agents - Google Patents

Abstract

A process for the preparation of water-soluble sulphonated dispersing agents by reacting sulphur dioxide with aromatic fractions in a weight ratio which is in the range from 0.8 : 1 to 1.5 : 1, the reaction taking place by means of: (1) a first step of the substantial sulphonation of the aromatic fractions in the presence of SO2, with a dominantly sulphonated product formed here; (2) a subsequent step of the removal of SO2 and heating of the solid sulphonated product to a temperature in the range from 70 DEG C to 110 DEG C; these two steps being carried out under the conditions in which the solid sulphonate is comminuted or pulverised and kept in motion.

Description

The present invention relates to an improved method for the preparation of water-soluble sulfonated dispersants or dispersants.

More particularly, the present invention relates to a process for preparing water-soluble sulfonated dispersants by effecting the reaction of aromatic fractions with SO ₃ .

The patent literature discloses methods which are useful for producing water-soluble sulfonated dispersants by effecting the reaction of aromatic fractions with SO ₃ . The interaction of the abovementioned aromatic fractions with sulfur trioxide under particular temperature conditions causes, in addition to the usual formation of sulfonates, an oxidative oligomerization.

The reaction of producing sulfonated dispersants by the reaction of aromatic fractions with SO ₃ is very complex. It is likely to be in a first stage with the substrates predominantly sulfonated and, in a subsequent step, a reaction of oxidative oligomerization involving the acrylates, especially those containing two or more rings in their molecule , predominates with an increase in molecular weight and evolution of SO ₂ . It can be assumed that during this stage the reaction proceeds in the following manner (I):

2 HR-SO ₃ H + SO ₃ → H ₃ OS-RR-SO ₃ H + SO ₂ + H ₂ O (I).

GB-A-2 159 536 discloses that this process is carried out is by using as the aromatic fraction Koksofenteer or a Fraction thereof and as a solvent a chlorinated verbin is used. The method has the disadvantage that the chlorinated solvent at least a minimum Decomposition occurs and so contaminated the dispersant and problems in solvent recovery and recycling caused.

EP-A-379 749 discloses a process wherein fractions of fuel oil are steam cracked with SO 3 using SO ₂ as solvent.

Compared with the method disclosed in GB-A-2 159 536 has the method disclosed in EP-A-379 749 doubt loose advantage that it is not the solvent decomposition Phenomenon shows and makes it possible that the same solution medium can be easily recycled.

Unfortunately, this method, in turn, has some drawbacks, mainly due to the difficulties encountered in seeking complete removal of SO ₂ and the need to work under pressure: in fact, a heating step is up to a maximum Temperature of about 120 ° C necessary. The incomplete removal of SO ₂ causes an increase in NaOH consumption during the neutralization step, resulting in the increase in sodium sulfite content in the final product.

The European patent application with the publication No. 0 580 194 discloses a process which is known as aroma table fraction of indene or mixtures thereof with the above given aromatic fractions of industrial origin used.

In any case, according to all these methods, the reaction in Presence of a solvent carried out, mainly around to remove the heat of reaction, which in very large amount before everything is developed during the sulfonation step.

According to the present application, a simplified Methods found that overcome the disadvantages mentioned above det, by the step of oxidative oligomerization in Ab Solvent is carried out. Accordingly be The present invention provides a method of preparation water-soluble sulfonated dispersant, wherein sulfur trioxide with aromatic fractions in a weight ratio in the range of 0.8: 1 to 1.5: 1 to Reaction is brought, which is characterized in that the se reaction by the following succession of stages is carried out:

• (1) predominantly sulfonating the aromatic fractions in the presence of SO ₂ at a temperature in the range of 5 ° C to 45 ° C to form a predominantly sulfonated product;
• (2) Removal of SO ₂ and heating of the solid sulfonated product to a temperature in the range of 70 ° C to 110 ° C and keeping the solid material at the above-mentioned temperature for a time which is in the range of 10 minutes up to 200 minutes;

wherein both steps are carried out under the conditions who that this solid sulfonate crushed and in motion is held.

According to a preferred embodiment of the present Er tion is the weight ratio of sulfur trioxide aromatic fractions in the range of 0.85: 1 to 1.3: 1.

Under "aromatic fraction", as this expression in used in the present specification, hydrocarbons understood substance compositions, which predominantly aroma are from different sources, eg. B. from the coal pyrolysis of the steam cracking of naphtha or Raw petroleum or gas oil or mixtures thereof, to light olefins from the production of lubricating oils. The expression "aromatic fractions" also includes Inden and the above he thought fractions mixed with inden.

In any case, the above-mentioned aromatic frak a minimum content of aromatics of 70 wt .-%, before preferably in the range of 80% to 100% by weight as indicated by column chromatography according to ASTM D 2549 agrees, with the addition to 100 of saturated and pola there are connections; the aromatic species of the above he mentioned fractions consist of at least 75% flavor and alkylaromatics with two or more fused or fused Rings.

The following meets these requirements:

• (1) fuel oil from steam cracking, d. H. the high-boiling liquid Residual from gasoline or petroleum and / or gas oil cracking of light olefins, especially ethylene (cf. "Ullmann's Encyclopedia of Industrial Chemistry", Vol. A 10, P. 47);  
• (2) coke oven tar, a by-product of coal pyrolysis (cf. "Ullmann's Encyclopedia of Industrial Chemistry", Vol. A 7, P. 275);
• (3) the so-called "aromatic extracts", by-products of the production of lubricants;
• (4) indene either alone or mixtures of indene with the above-mentioned fractions, as in the European patent application, publication number 0 580 194.

The "aromatic fractions" defined above also include Distillates or residues from processing or processing tion (eg distillation or extraction) of the abovementioned four groups as well as any compositions of any of origin, provided they are within the limits of the Aro content and type, as mentioned above.

In the preferred embodiment, the aromatic is Fraction of fuel oil from steam cracking.

The reaction of oxidative sulfonation (this term is used to designate the overall reaction involving sulfonation and oxidative oligomerization) occurs within a suitable pressure-resistant reactor in the presence of sulfur dioxide as the solvent. The pressure to be tolerated by the reactor is essentially a function of the sulfur dioxide vapor pressure at the reaction temperature. Since in practice the SO _{2 is present} only during the first reaction step, the pressure never exceeds 5 bar. This has a considerable improvement over the teachings disclosed in EP-A-379 749 result, where pressures in the order of 30 to 35 bar he can be enough. The possibility of operating at lower pressures involves considerable advantages, in particular with regard to the reactor materials and the waterproofing seals or closures.

SO ₂ can be used indifferently, either to dilute the aromatic fraction or the SO ₃ or both. Because of the ease with which SO ₃ tends to solidify as a result of even minimal temperature variations, it may be preferable for SO ₃ to be diluted with at least a portion of the SO ₂ . The ratio of SO ₂ to reactants is not critical; for the sake of fairness, a weight ratio of SO ₂ to reactants (where meant by reactants SO ₃ and the aromatic fraction) is preferably used in the range of 0.5 to 4.

By using the above-mentioned ratios of SO ₂ to reactants, the considerable amount of heat developed by the sulfonation reaction, meaning "sulfonation", is simply substituted for a hydrogen atom of an aromatic substrate by a -SO ₃ H half be removed. This removal of heat can be effectively effected by evaporating SO ₂ and / or cooling the reactor from outside. The pressure to be tolerated by the reactor in which the sulfonation takes place is essentially determined by the vapor pressure of the SO ₂ at the temperature at which the reactor is maintained.

The method according to the present invention can durchge be performed by either batch or continuously is working.

When the process is carried out batchwise, the sulfonation step can be carried out by gradually feeding SO ₃ , preferably diluted with SO ₂ , into the reactor containing the aromatic fraction preferably also diluted with SO ₂ . During this step, the temperature should be kept within the range of 5 ° C to 45 ° C, preferably 10 ° C to 40 ° C. Under these conditions of reactant concentration, the resulting sulfonated product is poorly soluble in the reaction medium and therefore prone to forming a solid product.

When this reaction step, which appears to favor the simple sulfonation of the aromatic substrates, is completed, the second stage of the process which consists therein begins the sulfonated product at a temperature in the range of 70 ° C to 110 ° C, preferably from 80 ° C to 100 ° C, to heat. During this step (by opening a top-controlled valve on the reactor head), the removal of SO _{2 is also} carried out. This operation can be carried out at the same pressure as the sulfonation step or at atmospheric pressure or under reduced pressure. SO ₂ is preferably gradually removed and the last traces thereof are preferably removed by rinsing with an inert gas or by operating under reduced pressure. The SO ₂ removal can be carried out by removing it at temperatures near the sulfonation temperature and then heating the solvent-free solid sulfonate, or SO ₂ can be removed simultaneously with the heating step during the second reaction stage. SO ₂ thus removed from the reactor can be condensed and recycled for a subsequent reaction.

It was observed that the absence of the solvent during this second reaction step in any way oxidative oligomerization is at risk.  

The residence time during this reaction step is generally in the range of 10 minutes to 200 minutes, preferably 20 minutes to 100 minutes, as a function of the molecular weight desired to be obtained by SO ₂ removal.

At the end of the procedure described above, the reaction product, now as a dry, friable powder from the reactor removed in solid form and then neutralized, or an aqueous solution of a base, preferably sodium hydroxide, in which the sulphonate is unquestionably soluble as a salt, can be added to the reactor.

For the procedure to be successful, it is essential that both the sulfonation step and the oxidative oligomerization step in the presence of appropriate Means for breaking and removing solid matter to be led. In fact, in the absence of such Mit tel, during the first stage, the sulfonate the whole reac fill the door volume, on the walls and all stationary parts attached to the reactor and in this way problems If the solid sulfonate must be removed to the to perform subsequent second process step.

With respect to the second step of oxidative oligomerization, only effective breakage of the solid product makes it possible to control the temperature with care and to avoid the thermal decomposition of the sulfonated product caused by local overheating, and makes it possible for the SO ₂ is easily removed. In addition, maintaining the solid product in motion is still required to remove it from the reactor.

For this purpose reactors are useful, which consist of a  horizontal cylindrical chamber consist with a Thermostatic jacket and with an axial shaft, the appropriate Shovels or blades is provided, which is in the Are able to move the material and, if necessary is the total loading of the same against a reactor discharge lead to the end.

This shaft or shaft can be designed so that he also contributes to the thermostat and the cylindrical reactor core can be provided with fixed counter blades or blades, which for Scrape the moving blades or blades ge are suitable.

If the procedure is carried out batchwise, the Reactor during the sulfonation step of cooling and during the subsequent step of the Solvent removal and oxidative oligomerization is the reactor is subjected to heating.

In the batchwise work, the method according to the prior invention can also be carried out by working with two reactors. In the first reactor, the sulfonation step is terminated and then the solid sulfonated product is discharged after previous removal of SO ₂ directly into the second reactor (already under operating temperature and pressure conditions) in which the second step of the oxidative oligomerization takes place.

If the procedure is carried out continuously, should two reactors in cascade, d. H. a chilled one A reactor in which the sulfonation is carried out, and a heated reactor wherein the oxidative oligomerization takes place should find. Except that the solid product crushed and in Movement is maintained, both reactors should be able  be, the solid product from the inlet apparatus to the outlet To transport equipment, so the continuous supply and to ensure distance.

In addition to the above-mentioned advantages (low NaOH consumption, almost complete absence of sodium sulfite in the final product, low working pressures), the process according to the invention makes it possible to recover the SO ₂ used as solvent and the SO ₂ produced during the oxidative oligomerization to an almost quantitative extent becomes.

The salted sulphonate is extraordinary in water soluble and as a dispersant for concentrated Mixtures of coal in water and as superplasticizer (superfluidizer) of concrete masses or compact masses ver reversible.

The dispersant may also at its various An as a concentrated aqueous solution or in solid Form after water removal can be used.

In those cases where that according to the invention Method produced sulfonate as a dispersant for CWM (coal / What sergemic is used, the effective amount lies within the range from 0.2% by weight to 1.0% by weight, based on the weight the total slurry, preferably from 0.4% by weight to 0.8% by weight.

In such cases where the sulfonate is used as Superverflüssi used for concrete compounds is its effective amount within the range of 0.4% to 1.5% by weight, bezo to the weight of the cement, preferably 0.5% by weight. to 1.0% by weight. In the production of concrete, the Sul according to the present invention, if appropriate  is considered, together with an antifoaming agent or De Mulgator be used.

The following examples are given to the present To explain the invention better.

Examples 1 to 4

A Reactor Discotherm B (Registered Trademark for List AG) of 1.5 liter capacity is used in the essential from a horizontal cylindrical body, out permitted with an axial stirrer. Such a stir rer is with scraper blades or blades, which over its entire length are distributed. On the body the cylindrical reactor are still suitable hooks provided shaped stripping arrangements, which the Rührblät keep it clean. On the shaft is a second order of stripping arrangements continue between the adjacent ones Shovels or leaves arranged, which in turn the Keep clean hook-shaped scraping arrangements.

The above-mentioned stirring arrangement is able to select the currency to move the solid material formed during the reaction and to mince. The reactor is further equipped with a cooling and / or or heating jacket applied on its coat is within which water can circulate.

Four tests are carried out in which the aromati used cal substrate fuel oil from a steam cracking process (FOK) is.

example 1

An amount of 221 g FOK diluted with 510 g SO ₂₁ is reacted with 224 g SO ₃ diluted with 440 g SO ₂ (total SO 2: SO ₃ : FOK equal to 4.3: 1: 1). The sulfonation is carried out at 27 ° C to 30 ° C, the solution of SO _{3 is} fed during a period of 57 minutes.

The system is held at about 30 ° C for 10 minutes, then heating is started and the valve on top is opened (heating time up to about 75 ° C: 53 minutes) to remove SO ₂ . The reaction mixture is held at 75 ° C to 89 ° C for about 30 minutes, the reaction is purged with nitrogen and kept under reduced pressure for about 15 minutes.

During the entire reaction time, the pressure was always low less than 5.0 bar.

The reaction mixture is diluted by adding 95 g of NaOH with 700 ml of water in the reactor to a pH of 8, 9 neutralized.

For analytical purposes, the aqueous solution is freeze-dried net, whereby 512.2 g of a solid obtained from 9.9% residual water, 11.75% Na ₂ SO ₄ , <0.5% Na ₂ SO ₃ , 78.4 % active substance.

The specific consumption, based on 1 kg of 100% dispersant, was found to be 550.4 g FOK, 557.9 g SO ₃ and 236.6 g NaOH.

Example 2

An amount of 333.3 g FOK diluted with 510 g SO ₂ is diluted with 269.2 g SO ₃ diluted with 560 g SO ₂ (total SO ₂ : SO ₃ : FO ₃ ratio equal to 3.21: 0.81: 1) reacted.

The sulfonation is carried out at 26 ° C to 30 ° C by feeding the solution of SO ₃ over a period of 39 minutes.

The system is kept at about 30 ° C for 10 minutes, then the heating is started and the one controlled above Valve opens (heating time up to about 77 ° C: 100 Minutes), the reaction mixture is at 77 ° C to 82 ° C currency held about 30 minutes and the reactor is under ver kept under pressure for about 15 minutes.

During the entire reaction time, the pressure was always low less than 5.0 bar.

The reaction mixture is by adding 107.5 g of NaOH, ver Dilute with 800 ml of water to the reactor to a pH neutralized by 9.8.

For analytical purposes, the aqueous solution is freeze-dried to give 669.6 g of a solid which consists of 4.3% residual water, 7.75% Na ₂ SO ₄ <0.5% Na ₂ SO ₃ , 88.0%. active substance.

Specific consumption data, based on 1 kg of 100% dispersant, were obtained with 566.0 g FOK, 457.1 g SO ₃ and 182.5 g NaOH.

Example 3

A quantity of 264.4 g FOK diluted with 415 g SO ₂ is diluted with 354.4 g SO ₃ diluted with 565 g SO ₂ (total SO ₂ : SO ₃ : FO ₃ ratio 3.71: 1.34: 1) reacted.

The sulfonation is carried out at 22 ° C to 29 ° C, the solution of SO _{3 is} fed during a period of 43 minutes.

The system is held at about 29 ° C for 10 minutes, then the heating is started and the top-controlled valve is opened (heating time up to about 77 ° C: 97 minutes). The reaction mixture is held at 77 ° C to 84 ° C for about 15 minutes and the last traces of SO ₂ are removed under reduced pressure (about 30 minutes).

Maximum pressure during the entire reaction time: 5.2 bar.

The reaction mixture is by addition of 133.1 g of NaOH, ver diluted with 900 ml of water, to the reactor to a pH neutralized by 8.5.

For analytical purposes, the aqueous solution is freeze-dried to give 712.3 g of a solid which consists of 7.1% residual water, 14.2% Na ₂ SO ₄ , <0.5% Na ₂ SO ₃ , 78.7 % active substance.

The specific consumption, based on 1 kg of 100% dispersant, was found to be 471.7 g FOK, 632.3 g SO ₃ and 237.5 g NaOH.

Example 4

An amount of 300.1 g FOK diluted with 650 g SO ₂ is diluted with 291 g SO ₃ diluted with 420 g SO ₂ (total ratio of SO ₂ : SO ₃ : FOK equal to 3.56: 0.97: 1). reacted.

The sulfonation is carried out at 25 ° C to 29 ° C by feeding the solution of SO ₃ for a period of 50 minutes.

The system is held at about 29 ° C for 10 minutes, then the SO ₂ venting is started by opening the top-controlled valve (60 minutes at about 27 ° C to 29 ° C); then the reaction is held under vacuum for about 30 minutes, removing the last traces of SO ₂ .

The heating is started under vacuum (25 mbar), the Temperature increased from 29 ° C to 80 ° C for 40 minutes is, the reaction mixture is still under reduced Pressure, maintained at 80 ° C to 82 ° C for about 30 minutes.

The maximum pressure (4.3 bar) is during the first sulphonation observed.

The reaction mixture is by addition of 110.6 g of NaOH, ver Dilute with 830 ml of water to the reactor to a pH neutralized by 9.0.

For analytical purposes, the aqueous solution is freeze-dried to give 627.7 g of a solid consisting of 6.2% residual water, 10.0% Na ₂ SO ₄ , <0.5% Na ₂ SO ₃ , 83.8 % active substance.

The specific consumption amounts, based on 1 kg of 100% dispersant, were found to be 570.4 g FOK, 553.1 g SO ₃ and 210.2 g NaOH.

Comparative Examples 5 to 7

The comparative examples were within a vertical Autoclave of 22 l capacity carried out with a magnetically operated stirring arrangement with a turbine of 180 mm diameter with four to 450 inclined blade was equipped. As the aromatic fraction was the same fuel oil from the steam cracking according to Examples 1 used until 4.

Comparative Example 5

A quantity of 4375 g FOK diluted with 4900 g SO ₂ is diluted with 3500 g SO ₃ diluted with 1540 g SO ₂ (total weight ratio of SO ₂ : SO ₃ : FOK = 1.47: 0.80: 1), sulfonated at a temperature in the range of 21 ° C to 37 ° C for 72 minutes. After 10 minutes at 37 ° C, the temperature is increased from 37 ° C to 80 ° C for 58 minutes and is held for 30 minutes at 80 ° C to 87 ° C, the venting of SO ₂ , which requires 40 minutes is started and the reactor is purged with nitrogen. The total reaction time was 260 minutes.

The maximum reaction pressure was 21 bar.

The reaction mixture is diluted with 1871.4 g of NaOH 15.5 liters of water, neutralized.

An amount of 9075 g of solid product is obtained which contains 4.68% water, 7.5% Na ₂ SO ₄ , 8.8% Na ₂ SO ₃ and 79.0% active substance.

The specific consumption data, still based on 1 kg of 100% dispersant, were obtained with 610.2 g FOK, 488.2 g SO ₃ , 261.0 g NaOH. In Example 2, where the same value of 0.8 1 was used for the SO ₃ : FOK ratio, the specific consumption data were considerably lower (566.0 g FOK, 457.1 g SO ₃ and 182.5 g NaOH).

Comparative Example 6

An amount of 4002 g FOK diluted with 4790 g SO ₂ is treated with 3940 g SO ₃ diluted with 1130 g SO ₂ (total weight ratio of SO ₂ : SO ₃ : FOK = 1.48: 0.98: 1). sulfonated at a temperature in the range of 17 ° C to 41 ° C for 52 minutes. After 10 minutes at 41 ° C, the temperature is increased from 41 ° C to 80 ° C for 57 minutes, is maintained at 80 ° C to 91 ° C for 30 minutes, the venting of SO ₂ , which requires 60 minutes, is started and the reactor is purged with nitrogen. The total reaction time was 265 minutes.

The maximum reaction pressure was 22.5 bar.

The reaction mixture is diluted with 2198 g NaOH, diluted to 16.0 Liters of water, neutralized.

A quantity of 8032 g of solid product is obtained which contains 5.97% water, 11.1% Na ₂ SO ₄ , 10.9% Na ₂ SO ₃ and 72.03% of active substance.

The specific consumption data, still based on 1 kg of 100% dispersant, were obtained with: 691.7 g FOK, 681.0 g SO ₃ , 379.9 g NaOH.

In Examples 1 and 4, where the same values of 1: 1 w / w were used for the SO ₃ : FOK ratio, the specific consumption data were significantly lower (in Example 1: FOK = 550.4 g , SO ₃ = 557.9 g, NaOH = 236.6 g, in Example 4: FOK = 570.4 g, SO ₃ = 553.1 g, NaOH = 210.2 g).

Comparative Example 7

An amount of 3035 g FOK diluted with 3240 g SO ₂ is added with 3930 g SO ₃ diluted with 1250 g SO ₂ (total weight ratio of SO ₂ : SO ₃ : FOK = 1.48: 1.29: 1) a temperature in the range of 15 ° C to 38 ° C during 62 minutes sulfonated. After 10 minutes at 38 ° C, the temperature is increased from 38 ° C to 100 ° C for 60 minutes, kept at 100 ° C to 111 ° C for 30 minutes, the venting of SO ₂ , which requires 58 minutes, is started and the reactor is purged with nitrogen. The total reaction time was 285 minutes.

The maximum reaction pressure was 35 bar.

The reaction mixture is diluted with 2075.3 g of NaOH, diluted to 16.0 Liters of water, neutralized.

An amount of 7714.3 g of solid product is obtained which contains 5.01% water, 14.5% Na ₂ SO ₄ , 4.6% Na ₂ SO ₃ and 72.89% active substance.

The specific consumption data, still based on 1000 g of 100% dispersant, were obtained with: 539.8 g FOK, 698.9 g SO ₃ , 369.1 g NaOH.

In Example 3, where the same value of 1.30: 1 was used for the ratio of SO ₃ : FOK, the specific consumption data were considerably lower (471.7 g FOK, 632.3 g SO ₃ and 237.5 g NaOH).

Evaluation of the fluidizing properties on CWM (Coal / water mixtures)

A type of carbon is subjected to a dry grinding treatment, to obtain granules with a maximum size of 3 mm. Then mixtures of this pre-ground coal, water and an organic sulfonate of Examples 1 to 7 posed. The organic sulfonate is in each mixture as active substance in an amount of 1 wt .-% present.

These mixtures are wet-ground using the subjected to the following grinding load:

• - 3.2 kg balls of AISI 420 steel of 31.75 mm diameter;
• - 4,8 kg balls of AISI 420 steel of 25,40 mm diameter;
• - 3.2 kg balls of AISI 420 steel of 12.70 mm diameter;
• - 4,8 kg balls of AISI 420 steel of 9,53 mm diameter; and a mill of 240 mm × 203 mm inside size.

1.8 kg of each mixture is made with a drum speed milled at 70 rpm (revolutions per minute). The Ver Grind is carried out for 2 hours until the middle one Diameter of carbon particles to about 7 to 8 μm (microns) was reduced.

Then the final grinding is carried out on a bar mill which has the same internal size as the colloid mill Has. The pre-milled coal (65% w / w) is added to this rolling mill. the coal was contained in the slurry) which he before produced micronized coal (containing the remaining 35% of the Coal) and possibly more water are added to a total weight of 1.4 kg. The resulting Konzentra tion of the additive is 0.5 wt .-%, based on the Enduspen sion.  

The grinding is for about 10 minutes down to a mitt smaller diameter of about 16 microns down, upper Size 25 μm (maximum 1% to 2% retentate at 250 μm).

Then, the final stirring of the product, that of the bar roll plant comes at around 20 ° C, so its rheolo be optimized. This stirring will on a laboratory scale with a paddle stirrer at 450 rpm carried out.

The viscosity values of the slurries are carried out with a Contraves Rheomat 115 rotational viscometer with DIN 145 coupling, which is thermostated at 20 ° C ± 0.2 ° C. The rheological behavior of the slurries was evaluated by measuring the apparent viscosity at 10 sec ^-1 .

The phenomenon of slurry disintegration during pumping (or evaluation of dynamic stability) is simulated by stirring 200 g of the slurry, which is thermostated at 20 ° C, at 1000 rpm with an IKA-Werk Laboratory Mixer Model KW20DZM equipped with stainless steel paddle stirrer. As the end point of the disintegration test, a value of shear stress at 10 sec ^-1 , which is about twice the value with respect to the initial value, is assumed. The time required to reach this value is considered to be the index of pumping resistance or dynamic stability of the slurry. It should be noted that the high agitation speed (1000 rpm) is only chosen to accelerate the decomposition process, so the results obtained should be considered for comparative purposes only and do not represent the efficacy of the slurry under working pumping conditions ,

The granulometric distribution of the coal is used tion of a laser diffraction particle size analyzer.

Table 1 shows the properties of the slurries, mixed with the sulfonated products according to the example 1 to 4, and in the comparative examples of FIG. 5 to 7 using a Polish coal with the consequences the characteristics (measured on the dry coal): flee 30.5%, ash 9.87%, and solid carbon (by Difference) 59.98%. All these percentages are on the Ge based on weight.

The information on viscosity and pump stability are reported as relative values compared to the characteristics which by use under otherwise identical conditions of a han The usual additive can be obtained to the same class the sodium naphthalenesulfonates / formaldehyde condensates belongs.

As for the viscosity of the slurry, so is a Value lower than 1 indicative of the ratio of a height fluidizability of the product according to the present invention Invention as the commercial product.

A value greater than 1 for pump stability indicates the over greatness of the products according to the present invention above the commercial product, taken as a comparison is.

Table 1

The values reported in Table 1 show that the products according to the present invention, prepared under a lower pressure and with a lower consumption of reactants, show a quality on concentrated coal mixtures in water which is about equal to the products which are within a usual range Reactor produced under pressure, which still work in the presence of SO ₂ .

Evaluation of superfluidizing properties

- Tests on concrete.

The additives or additives according to Examples 1 and 7 of The present invention has been made in terms of fluidity Characteristics of fresh concrete and mechanical Properties of the concrete structure evaluated.

For each concrete formulation, the following formulation was used wherein the percentage of superfluidizers and Defoamer additive is based on cement.

Sand 0 to 3 mm | 22.4 kg Gravel 6 to 25 mm 22.4 kg Portland cement quality 425 10 kg Superfluidisier additive 0.7% Antifoam additive 0.04% water to fill up to get the desired slump.

The slump was on the fresh concrete measured and then concrete cubes were made under Ver Use of metal cube molds of 150 mm side length, the arranged on a vibrating table, as by UNI standard delivered.

After 24 hours of setting time, the cubes were removed from the molds and allowed to age in water for 28 days. On the cubes thus prepared, compressive strength is measured after 28 days, expressed in kg / cm ² . For the purpose of comparison, the values are given which refer to concrete without additives or additives and to concrete mixed with a commercial superfluidizer belonging to the class of sodium naphthalene sulfonate / formaldehyde condensates. The values are given in Table 2, where W / C is the weight ratio of water to cement.

Table 2

The data given in Table 2 show that the after products of the invention superfluidi show properties which are approximately equivalent the superfluidizing properties which are determined by han conventional products are shown and produced by such products te, which produced within a conventional pressure reactor are.

Claims (13)

A process for preparing water-soluble sulfonated dispersants by reacting sulfur trioxide with aromatic fractions in a weight ratio in the range of 0.8: 1 to 1.5: 1, characterized in that the reaction takes place by means of the following sequence of steps:

• (1) predominantly sulfonating the aromatic fractions in the presence of SO ₂ at a temperature in the range of 5 ° C to 45 ° C to form a predominantly sulfone-containing product;
• (2) Removal of SO ₂ and heating of the solid sulfonated product to a temperature in the range of 70 ° C to 110 ° C and holding the solid material at the above-mentioned temperature for a time in the range of 10 to 200 minutes ;

these two stages being carried out under conditions be that this solid sulfonate crushed and in evidence is held. 2. The method according to claim 1, characterized in that this stage 1 at a temperature in the range of 10 ° C to 40 ° C and the stage 2 at a temperature in the Be rich from 80 ° C to 100 ° C is performed. 3. The method according to claim 1, characterized in that both stages are carried out under conditions that  crushed this solid material, kept moving and to Progression is caused. 4. The method according to claim 1, characterized in that the aromatic fractions have a minimal content Should have aromatics of 70 wt .-%, wherein the Er Supplement to 100 of saturated and polar compounds consists; wherein the aromatic species of the above-mentioned Fractions of at least up to 75% from aromatics and Alkylaromatics with two or more condensed rings consist. 5. The method according to claim 4, characterized in that the aromatic fractions have a minimal content Have aromatics of 80 wt .-%. 6. The method according to claim 1, characterized in that the aromatic fractions from heating oil from the steam consist of cracking. 7. The method according to claim 1, characterized in that the weight ratio of SO ₂ : reactants in the range of from 0.5 to 4. 8. The method according to claim 1, characterized in that the weight ratio of sulfur trioxide: aromatic Fractions is in the range of 0.85: 1 to 1.3: 1. 9. Concentrated dispersion of coal in water, thereby characterized in that this dispersion additionally an amount from 0.2 to 1% by weight of the sulfo converted into a salt ned dispersant prepared according to the method ren of claim 1, contains.   10. Concentrated dispersion of coal in water according to An claim 9, characterized in that the dispersing with in an amount in the range of 0.4 to 0.8% by weight is present. 11. concrete composition, characterized in that these Composition in addition a lot in the range of 0.4 to 1, 5 wt .-%, based on cement, of the sulfonated A product prepared according to the method of claim 1, contains. 12. Concrete composition according to claim 11, characterized gekenn characterized in that the sulfonate is present in an amount in the range from 0.5 to 1.0% by weight, based on cement.