JPH0369389B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a dispersant for coal/water slurry for producing and using coal/water slurry used as raw fuel. [Problems to be solved by conventional techniques and inventions] Due to the two oil shocks, the system of dependence on oil as an energy source or raw material is currently changing. Energy sources have shifted to the use of a wide variety of energies such as nuclear power, natural gas, hydropower, coal, and petroleum coke, and coal as a raw material has been reviewed from many angles. There is. However, since coal and petroleum coke are solids, they still have many problems in transportation, storage, combustion, etc. In the case of coal, solving so-called transportation problems, such as transporting it from the site of adoption and shipping it to freight cars or ships, is an issue in order to make more effective use of solid raw fuels such as coal. As one method, a method has been proposed in which coal is dispersed in a liquid such as water, methanol, or petroleum, and then transported by pipeline. Among these methods, the method of dispersing coal powder in water to form a slurry has various advantages and has been put into practical use in some cases. However, increasing the coal concentration in the slurry deteriorates the fluidity of the slurry, causing problems in terms of transportation efficiency, combustion efficiency, etc., and it has not been widely used. As a method of increasing the concentration of coal/water slurry, proposals have been made such as adjusting the particle size of coal powder and adding a dispersant. As a dispersant for coal/water slurry, lignin sulfonate is already known (Japanese Patent Application Laid-Open No. 71506/1986).
There is also a naphthalene sulfonic acid formalin condensate (Japanese Patent Publication No. 60-6395), but it is still insufficient for practical use, and although it varies depending on the type of coal used, the coal concentration is 60%.
Above that, the fluidity decreases. The present inventors have discovered that naphthalene sulfonic acid (hereinafter referred to as NS)
It is abbreviated as ) Lignosulfonic acid (abbreviated as LSA)
Continuing long research on salt and HCHO-based reactions,
We have also continued to conduct intensive research on the types of LSA salts used in the reaction and the denaturation methods. As a result, NS,
When reacting LSA salt and HCHO, we succeeded in developing a high-performance dispersant for coal/water slurry by dividing NS and adding it to LSA salt and HCHO alternately and reacting. As a prior art, JP-A-58-34896 discloses a method in which a condensation reaction product of NS, an LSA derivative [desulfonated lignin sulfonate (DSL)], and HCHO is used as a dispersant. In addition, it is stated in JP-A-60-26090 that the ligninsulfonic acid to be co-condensed is obtained by sulfonating wood chips, and its chemical treatment process, hydrolysis reaction, oxidation reaction, desulfonation reaction, demethylation reaction, etc. It refers to modified ligninsulfonic acid that has undergone a chemical reaction, etc., and condensed ligninsulfonic acid that has undergone a condensation reaction. However, in this case only the reaction process in general is illustrated. For example, when considering one oxidation reaction, the modified lignin sulfonic acid will vary depending on the chemical used for the oxidation reaction and the extent of the reaction. Therefore, if the chemical treatment is not appropriate, it will have a negative effect. The method disclosed in Japanese Patent Publication No. 58-34896 is obtained in accordance with the method described in Japanese Patent Publication No. 52-24533. Therefore, this method can be interpreted as applying a reaction-treated cement dispersant to a coal-water slurry. In addition, in the field of cement dispersants,
5051, 60-5052 are disclosed. This is DSL
Instead, an ultrafiltered LSA salt is used to perform a condensation reaction, followed by an oxidation reaction. However, although cement and pulverized coal seem to be similar in that they handle the same fine particles, the former is an inorganic substance and is a hydraulic substance, whereas the latter is an organic substance and has no hydraulic properties, and they also have different surface structures. . In particular, in the case of the former dispersant, in addition to high dispersibility, concrete setting retardation and air entrainment properties are important. When the degree of condensation is low, the amount of entrained air increases, so the degree of condensation of the reactant is important and it is common to use a high condensate. On the other hand, in the latter case, in addition to dispersibility, emphasis is placed on the storage stability of the resulting coal/water slurry. Therefore, it is natural that the manufacturing method of the optimal dispersant used for this will vary. The purpose of the present invention is to provide coal/slurry systems with
By adding this dispersant, the fluidity of the slurry is improved, and it shows excellent fluidity even at a high concentration of 60% or more, and it is easy to transport coal by pumping.
The object of the present invention is to provide a dispersant capable of producing an aqueous slurry. [Means for solving the problem] The dispersant for coal/water slurry according to the present invention is characterized in that it consists of a reaction product obtained by alternately and sequentially adding NS, LSA salt, and HCHO as active ingredients of the dispersant. do. An example of a basic manufacturing method for the dispersant for coal/water slurry of the present invention is shown below. Add sulfuric acid and water to the divided NS, heat it to 80-95℃, and then
% HCHO over 1-2 hours. To this add LSA salt + HCHO, then NS + HCHO. In this way LSA
Salt + HCHO and NS + HCHO are added sequentially and alternately, and the reaction is carried out for 5 to 25 hours while maintaining the liquid temperature at 90 to 130°C. After the reaction is complete, the product is cooled to room temperature and neutralized with an alkali to remove inorganic salts. The proportions of chemicals used in the reaction are as described below. The LSA solution is used in an amount of 10 to 60 parts, preferably 15 to 50 parts, per 100 parts of NS. If the amount of LSA salt is too high,
The amount of unreacted NS increases, and the performance as a dispersant for coal/water slurry decreases. Furthermore, if the amount of LSA salt is too small, the product becomes close to a condensation product of NS alone, and the characteristics of the present invention cannot be exhibited. Initially, NS is 20-40% of the total, and the amount of HCHO is 20% for 100 parts of NS.
~30 copies is appropriate. In the case of LSA salt, 20 to 50 parts of HCHO, which is added alternately and sequentially with LSA salt and NS, is preferably 20 to 50 parts per 100 parts of LSA salt, which is added sequentially and alternately.
In the case of NS, 15 to 30 parts per 100 parts of NS is suitable. Above each upper limit, formalin remains, and below the lower limit, the reaction becomes insufficient. The appropriate number of alternating cycles is 10 to 20 times. When first mixed with NS, water and sulfuric acid will be 100 parts of NS and 10 to 40 parts of water.
The amount is preferably 15 to 30 parts, and 20 to 50 parts of sulfuric acid is suitable. If the amount of water is too large, the reaction will take too long, and if the amount is too small, the viscosity will become too high, making stirring in a reaction tank or the like difficult. Reaction temperature is 90-130
C. and the reaction time is preferably 5 to 25 hours. If the reaction temperature is too low, the reaction rate will be slow, and if the reaction temperature is too high, it will be difficult to control the reaction. The reaction time is naturally closely related to the reaction temperature, but if the reaction time is 5 hours or less, there will be a large amount of unreacted substances. Used in the present invention
The LSA salt is preferably an LSA salt having a degree of sulfonation of 0.8 to 0.2 per phenylpropane unit. The HCHO reactant obtained by the above reaction is
After neutralization, alkali metal salts, ammonium liquid,
It is made into lower amine salts, etc. The coal/water slurry to which the dispersant of the present invention is applied is not particularly limited as long as it is used as a raw fuel. Examples of the types of coal include brown coal, subbituminous coal, bituminous coal, and anthracite coal. Another example of carbonaceous powder similar to coal is coke produced from coal. There is no particular restriction on the particle size of coal, etc., but if the particle size is too large, stability will remain a problem, so it is generally 200 Mesh pass (74 μm or less) 50% by weight or more, preferably 60 to 90%. In the present invention, it is also possible to use together known additives and dispersants such as CMC, MC, polyacrylates, NSF, and LSA salts. [Function] In the present invention, what is the structural difference between the reaction products obtained by applying the alternating sequential addition method of NS, LSA salt, and HCHO-based reactions compared to those produced by conventional production methods? It is not clear whether However, in the conventional method, the reaction between the NSF oligomer and the LSA salt is considered to be the main reaction, whereas the alternating sequential addition method of the present invention
Since the LSA salt and HCHO are supplied sequentially, it is presumed that the main reaction is the reaction with methylol or the reaction with the NSF oligomer, which has a very low degree of condensation. The reason why the performance of the dispersant of the present invention is improved compared to the conventional method is not clear, but the products formed by the above-mentioned reaction are effectively adsorbed onto the coal particles, promoting the dispersion of the coal slurry and improving its stability. It is thought that this also contributes. [Effect of the invention] NS,
By using a dispersant for coal/water slurry reacted with LSA salt and HCHO, the fluidity of the slurry is improved, and especially coal that shows excellent fluidity even at high concentrations of 60% or more and is easy to pump.・Water slurry can be obtained. [Example] Preparation of NS, LSA salt, and HCHO reaction product〓Product of the present invention〓 A mixture of 35 parts of NS, 15 parts of 98% sulfuric acid, and 10 parts of water was mixed with 80 parts of NS, LSA salt, and HCHO reaction product.
Heated to ~90°C and added 9 parts HCHO over 1 hour, followed by 65 parts NS and 17 parts HCHO, LSA salt.
10 of each solution consisting of 25 parts and 10 parts formalin.
The mixture was added alternately in batches, and the reaction was carried out at 95 to 120°C with stirring for 20 hours. After the reaction was completed, the mixture was cooled and neutralized with a sodium hydroxide solution to crystallize and remove inorganic substances. 〓Comparative example〓 A mixture of 100 parts of NS, 35 parts of 98% sulfuric acid, and 20 parts of water was mixed with 80 parts of
Heated to ~90°C and added 23 parts HCHO over 2 hours. After that, a solution consisting of 20 parts of LSA salt and 15 parts of HCHO was added in 4 parts, and the mixture was heated at 95 to 100°C for 19
The reaction was allowed to proceed with stirring for a period of time. After the reaction was completed, the mixture was cooled to room temperature, neutralized with a sodium hydroxide solution, and inorganic substances were crystallized and removed. Coal/water slurry preparation method and fluidity measurement method
Add bituminous coal that has been crushed to 80% pass (total amount: 400 g), thoroughly wet it with a mixing rod (make a paste), and stir for 40 minutes at 8000 rpm using a TK homo mixer manufactured by Japan Tokushu Kika Kogyo. A coal/water slurry was prepared using a BL-type rotational viscometer at 20°C, and the viscosity of the slurry was measured using a BL-type rotational viscometer. Examples and comparative examples conducted under these conditions are shown in Table 2. Low viscosity indicates good fluidity. Stability measurement method for coal/water slurry Transfer the coal/water slurry prepared under the above conditions to a cylinder (inner diameter 35 mm, height 250 mm),
A glass rod weighing 30 g was penetrated into the slurry, and the falling state was measured over time. If the glass rod penetrates all the way to the bottom due to its own weight, the stability of the slurry is good, but if it stops at more than 1/2 of the way and does not penetrate downward even when pushed by hand, the stability becomes poor. Examples and comparative examples in which the stability of the slurry was measured under these conditions and the number of days it lasted are shown in the table. Those that last for a long time have good stability and are indicated by ○.

【table】

【table】

[Table] As is clear from the results in Table 2, in the case of the present invention, a slurry with an equivalent low viscosity can be obtained with a much smaller addition amount than in the case of the comparative example, and a slurry with excellent stability can be obtained. , the superiority of the present invention is recognized.

Claims (1)

[Scope of Claims] 1. After adding sulfuric acid, water, and then formalin to a portion of naphthalene sulfonic acid and/or alkyl naphthalene sulfonic acid in advance, lignin sulfonic acid or its salt, and the remaining naphthalene sulfonic acid and/or alkyl naphthalene sulfonic acid are reacted. Naphthalenesulfonic acid with the necessary formalin for 10~
Coal whose active ingredient is a reaction neutralization product obtained by a reaction method of alternating and sequential addition in 20 times.
Dispersant for water slurry. 2 The total addition ratio of naphthalene sulfonic acid and/or alkylnaphthalene sulfonic acid to lignin sulfonic acid or its salt is 90:10 by weight.
The dispersant for coal/water slurry according to claim 1, wherein the ratio is 40:60.