JPS62169895A - Dispersant for coal-water slurry - Google Patents

Abstract

PURPOSE:To provide the titled dispersant having an excellent viscosity decreasing effect, storage stability and economical efficiency, which comprises, as an active ingredient, a product obtd. from a particular modified ligninsulfonate, naphthalene(di)sulfonic acid, and formaldehyde. CONSTITUTION:Sulfite cellulose pulp waste liquid (a) is mixed with NaOH (b) in an amt. of 5-20% based on the solid content of the component a. The mixture is kept at 150-200 deg.C for 1-2hr while air or oxygen is blown into the mixture, thereby causing an oxidation reaction and obtaining a modified ligninsulfonate (D). Sulfuric acid and water are added to a mixture of 100pts.wt. (hereinafter referred to as 'pts.') naphthalenesulfonic acid (A) with 5-20pts. naphthalenedisulfonic acid (B) composed mainly of 6-naphthalenedisulfonic acid to allow the mixture to acidity. The acidified mixture is heated at 80-95 deg.C and mixed with 20-25pts. about 37% formaldehyde (C) and then with 20-100pts. component C and 5-50pts. component D. The mixture is allowed to react at 90-120 deg.C for 5-20hr. The reaction product is used as an active ingredient and neutralized to obtain the titled dispersant.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a dispersant for coal/water slurry.

Specifically, it relates to a reaction product of a modified lignin sulfonate, naphthalene disulfonic acid, and naphthalene sulfonic acid under acidic conditions.

(Conventional technique) A method of using lignin sulfonate (LSA salt) or naphthalene sulfonic acid formaldehyde condensate (NSF) salt as a dispersant for coal-water slurry (hereinafter abbreviated as CWM) is disclosed in JP-A-52-71506. , is already known in Japanese Patent Publication No. 60-6395.

As a patent that further developed this, naphthalene sulfone l (NS>triginine sulfonic acid (LSA) derivative [
A method is disclosed (Japanese Patent Laid-Open No. 34896/1983) in which a condensation reaction product of desulfonated lignin sulfonate (DSL>) and formaldehyde (+-ICHO) is used as a dispersant.

Furthermore, in JP-A-60-26090, the ligninsulfonic acid to be co-condensed is obtained by sulfonating wood chips to obtain 1q, and the chemical treatment process, hydrolysis reaction, oxidation reaction, desulfonation reaction and demethylation Modified ligninsulfonic acids that have undergone reactions and condensed ligninsulfonic acids that have undergone condensation reactions are shown.

However, in this case, the general reaction process was simply reversed. 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 chemical treatment is not appropriate, it will have a negative effect.

The method disclosed in Japanese Patent Publication No. 58-34896 is similar to the method described in Japanese Patent Publication No. 52-25433.

Therefore, this method can be interpreted as applying reaction treatment to make it suitable for cement dispersants to CWM.

In the field of cement dispersants, JP-A-60-5051.
60-5052 is disclosed.

This method uses an ultrafiltered LSA salt instead of DSL, which is subjected to a condensation reaction, and then subjected to an oxidation reaction treatment.

However, although cement and pulverized coal are similar at first glance in that they handle the same fine particles, the former is an inorganic and hydraulic substance, while the latter is an organic substance and has no hydraulic properties, and their surface structures are also different. There is.

Particularly 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 generally used as a high condensate.

On the other hand, in the latter case, in addition to dispersion, the resulting CWM
The storage stability of the product is important.

Therefore, it is natural that the manufacturing method of the optimal dispersant used for this differs.

[Problem that the invention seeks to solve]

An economical and high-performance dispersant for CWM that can withstand industrial use is currently unknown.

Here, a high-performance dispersant is one that is less affected by the type of coal and is excellent in the following points: (1) It has a large viscosity-reducing effect with a low additive content.

(2) High storage stability.

That's true.

[Means for solving the problem] The present inventors NS,! =LSA salt and C of MCl-10 series
As a result of detailed and intensive research on WM dispersants, we succeeded in creating a high-performance fractional dispersant for CWM by using a special lignin sulfonate treated with naphthalene disulfonic acid and an oxidation reaction.

That is, the present invention deals with LSAta subjected to high-temperature alkaline air oxidation treatment.
The biggest feature is that NS and HCHO are reacted with naphthalene disulfonic acid whose main component is 2,6-naphthalene disulfonic acid.

More specifically, the SO3 group of sulfite pulp waste liquor (SSL) is left as is, that is, it is not subjected to a vigorous oxidation reaction until a desulfonation reaction occurs (like DSL, it is not subjected to a violent oxidation reaction until a precipitate occurs under acidic conditions). , other functional groups such as phenolic OH and carboxyl groups, and at the same time conduct an appropriate oxidation reaction so that reducing a!!s and sugar modifications other than LSA salts do not become reaction inhibiting substances.

Specifically, NaOH is 5 to 20% of the SSL solid content.
Wet oxidation is carried out at a temperature of 150 to 200° C. for 1 to 2 hours while blowing air or oxygen.

Naphthalene disulfonic acid (NDS>) mentioned here is 2,6
-Mainly composed of naphthalene disulfonic acid and 2,7 others
- Refers to substances containing naphthalene disulfonic acid, etc.

Both the thus obtained modified LSA salt (TLS=) and NDS are used to react with NS and 1-ICHO.

This method is carried out according to Japanese Patent Publication No. 52-25433, and will be specifically described below.

The basic manufacturing method for dispersants is to add sulfuric acid and water to NS and NDS, heat this to 80-95°C, and then add 37% H
Add CHO over approximately 2 hours.

Add 1cHO and TLS- to this, and add 90 to 12
The mixture is reacted at 0°C for 5 to 20 hours, neutralized, and the inorganic salt removed to obtain a product.

The ratio of chemicals used in the reaction is 5 to 50 parts (by weight, the same applies hereinafter) to 100 parts of N3 for TLS-, preferably 15 parts.
~40 copies.

If it exceeds 50 parts, unreacted NS increases, which is not preferable. Moreover, if it is less than 5%, it becomes close to NSF and the characteristics of the present invention are not exhibited.

NDS is 5 to 20 parts per 100 parts of N5, preferably 1
0 to 15 parts is good.

Next, the l-I CHOfJ used first is suitably 20 to 25 parts per 100 parts of N5.

The amount of H CHO added together with TLS' is 20 to 100 parts per 100 parts of TLS.

The water and sulfuric acid that are first mixed with NS are 3100 parts of N,
The amount of water is 15-30 parts, preferably 18-25 parts, and the amount of sulfuric acid is 20-40 parts.

The reaction temperature is 90-130°C and the reaction time is 5-20 hours.

In the present invention, the HCHO reactant is neutralized to form an alkali metal salt, an ammonium salt, a lower amine salt, or the like.

Examples of the alkali metal salts include Na, Li, and ion salts, and examples of the lower amine salts include monoethanolamine, jetanolamine, and triethanolamine salts.

Coal to which the dispersant used in the present invention is applied is not particularly limited, such as brown coal, subbituminous coal, bituminous coal, and anthracite coal.

There is no particular restriction on the particle size of the coal, but it is preferably 50% or more, preferably 70 to 80%, which passes through 200 meshes.

In the present invention, it is also possible to use known additives such as CMC, MC, polyacrylates, and condensed phosphates.

Other dispersants such as NSF and LSA salts can also be used in combination.

[Effect]

In the present invention, DSL, in which the combined system of TLS' and NDS obtained by oxidation reaction treatment under special conditions could be used in the past;
It is not clear what kind of reaction is different from the reaction system with NS and HCHO.

However, DSL has less 303 H, so if the parent is increased, precipitation will occur in the reaction system, whereas
This does not occur in the case of TLS-.

Moreover, the number of functional groups such as phenolic OH and carboxyl groups is increased compared to ordinary LSA salts, and the reducing sugars and sugar modifications are in a form that does not inhibit the reaction, resulting in higher reactivity. Conceivable.

NDS used in combination has a negative effect when producing high-performance water reducer NSF high condensation using ordinary concrete admixtures, but it has a positive effect when used in combination with TLS as in the present invention.The reason for this is unknown, but This seems to be related to the affinity with TLS'.

It is presumed that as the proportion of the functional [1, LSA salt] of the reactant increases, the affinity for coal increases, resulting in a higher performance dispersant.

〔Example〕

<Preparation of special lignin sulfonate (TLS)> Na (SSL-Na) of sulfite pulp concentrate was adjusted to DH12 with NaOH and oxidized with alkaline air at a high temperature of 150 to 160°C for 2 hours.

<Preparation of N5-NDS-TLS=・HCHO reaction product> 380 parts of N, 320 parts of ND, 35 parts of 98% H2SO beef,
A mixture of 20 parts of water was heated to 80-90°C and 37% HC
23 parts of H0 were added over 2 hours.

After that, a solution consisting of 30 parts of TLS and 23 parts of 37% HCH0 was added in 4 portions at 1 hour intervals.
The reaction was carried out with stirring at 'C for 2 hours.

After reaction completion, cooling, neutralization with Naol-1, NazS
O cows were removed by crystallization. (A1) In the case of DSL, the reaction was carried out in the same manner. (B]) Other people -
A2 was reacted in the same manner as shown in 1.

<Coal/water slurry preparation method and fluidity measurement method> 1)
Preparation method of coal/water slurry: 200ml
Please add bituminous coal crushed to 80% pass.
After wetting it thoroughly with f14001 mixing stick (making it into a paste),
800 using a homo mixer to T manufactured by Nippon Tokushu Kika Kogyo.
A coal/water slurry was prepared by stirring at 0r, p, m for 40 minutes, and the slurry viscosity was measured at 20'C using a BL type rotational viscometer. Examples and comparative examples conducted under these conditions are shown in Tables 1 and 2. Low viscosity indicates good fluidity.

2) Stability measurement method for coal/water slurry]) Coal/water slurry prepared under the conditions of
35m in inner diameter, 250m in height), diameter 6#, weight 3
A glass rod weighing 0 g was inserted into the slurry, and the falling state was measured over time. If the glass rod penetrates downward due to its own weight, the stability of the slurry is good, but if it stops at 1/2 or more of the way and does not penetrate downward even when pushed by hand, the stability becomes poor.

Tables 1 and 2 show Examples and Comparative Examples in which the stability of the slurry was measured under these conditions and the number of days it lasted. A longer duration indicates better stability.

Table-1 Table-2 [Effects of the invention] According to the present invention, instead of conventional DSL, TLS” and N
DSfj: By using in the reaction with NS and HCHO, a high-performance dispersant for CWM can be obtained.

When both TLS- and NDS are used, as shown in the above example, the amount added is smaller than that of a dispersant using DSL, and there is less influence by the type of coal.

This is thought to be because the ratio of genin sulfonate in the reactant became high, which increased its affinity with coal.

When using the conventional DSL (Japanese Patent Publication No. 58-34896), the limit was 130 parts of DS compared to 3100 parts of N, whereas in the case of TLS of the present invention, up to 50 parts can be used.

Therefore, the amount can be increased to about 1.5 times the conventional amount.

Claims (2)

[Claims] (1) Coal whose active ingredient is a reaction product of modified lignin sulfonate treated with oxidation reaction, naphthalene disulfonic acid, naphthalene sulfonic acid, and formaldehyde.
Dispersant for water slurry. (2) The ratio of modified ligninsulfonic acid, naphthalene disulfonic acid, and naphthalene sulfonic acid is 10 to 50:5.
20:100 parts of the dispersant for coal/water slurry according to claim 1.