JPS5837090A - Viscosity depressant for highly concentrated coal/water slurry - Google Patents

Abstract

PURPOSE:To provide the titled viscosity depressant having excellent viscosity- reducing effect, containing, as an active component, a co-condensate obtd. from a sulfonated product of a polycyclic arom. compd., an imino group or thiocarbamoyl group-contg. compd., and an aliph. aldehyde. CONSTITUTION:A sulfonated polycyclic arom. compd. which may be substituted with a hydrocarbon group, such as naphthalenesulfonic acid or lignosulfonic acid, an imino group compd. such as guanidine and/or a thiocarbamoyl group-contg. compd. such as urea or thiourea, and an aliph. aldehyde such as formalin are subjected to a co-condensation reaction. The resulting co-condensate or its salt is incorporated as an active component to obtain the desired viscosity depressant for a highly concentrated coal/water slurry. The viscosity depressant is used in an amount of 0.01-5wt% based on that of the slurry.

Description

[Detailed description of the invention] The present invention relates to a thinner for coal-water slurries.

More particularly, it relates to a thinning agent for dispersing pulverized coal in water to provide a highly concentrated coal-water slurry that can be pumped.

In recent years, due to the depletion of oil resources, the use of coal has been reconsidered.
Various ways of using it are being considered. However, unlike oil, coal is a solid and cannot be transported by pump. For this reason, various methods are being considered for pulverizing coal and dispersing it in water to form a water slurry. However, with current technology, this method becomes difficult to pump as increasing the coal concentration significantly thickens the coal and loses its fluidity.

On the other hand, lowering the coal concentration reduces transportation efficiency and requires a dehydration process before combustion, which is expensive and impractical.

Japanese Patent Publication No. 52-71506. 1982-21636 describes naphthalene sulfonic acid salts and their formalin condensates, but when these compounds are used alone, the viscosity-reducing effect is weak, and when the coal concentration is 61% or more, At high concentrations, the viscosity increases rapidly and glucidity occurs, making practical pump transportation difficult.

The present inventors fluidized a highly concentrated coal-water slurry,
We have conducted intensive research into a thinning agent for coal-water slurry that enables pumping, and with the addition of a small amount, the viscosity of coal-water slurry can be significantly reduced.As a result, coal can be transported by pump even at high coal concentrations. Successfully developed a viscosity reducing agent that provides water slurry.

By using the thinner of the present invention, coal can be fluidized with a small amount of water, making it possible to not only transport it by pump, but also to burn it in a boiler as it is, and also eliminate the dehydration step before combustion. be able to. By using the thinning agent of the present invention, handling of coal becomes extremely simple, and its applications are greatly expanded.

The coals used in the coal-water slurry include anthracite, bituminous coal,
Any type of coal may be used, such as sub-bituminous coal, lignite, or IJ-carbonized coal. In addition, the particle size of the coal in the water slurry may be any particle size as long as it is powder, but since the pulverized coal currently burned in thermal power plants is 70% or more of 200 mesh pass, this particle size is suitable for pulverized coal. This is a guideline for the particle size. However, the thinner of the present invention is not affected by particle size and exhibits excellent effects on coal powder of any particle size.

Cleaned coal is coal from which inorganic substances such as ash and sulfur have been removed.

Methods for cleaning coal include, for example, heavy liquid separation method and Oi I Agglomeration method (hereinafter referred to as OA).
There are methods such as flotation method) and flotation method. However, methods other than these may also be used and are not particularly limited.

Regarding the OA method, after dry or wet pulverization of coal, a water slurry is prepared and a suitable oil is added, or after the coal is coated with oil in advance, a water slurry is prepared and stirred. By utilizing the difference in wettability of the organic and inorganic components of coal to oil and water, the organic components of the coal are selectively removed and the oil is used as a binder to cause aggregation of the organic components of the coal. On the other hand, since inorganic substances have a weak affinity with oil, they are liberated in water, so this method can simultaneously remove inorganic substances by separating water from coagulated coal. The coal concentration in the coal 7 water slurry of the OA method is usually 10 to 65%.

The oil used in the OA method is crude oil or various fractions obtained from crude oil, such as kerosene, light oil, A heavy oil, B heavy oil, Cu
These include oils commonly used as fuel, such as tar, pre-shale or ethylene decomposition residual oil, or various blended oils, and mineral oils such as lubricating oils and cleaning oils. Water-insoluble oils such as benzene, toluene, xylene, and animal and vegetable oils may also be used, but heavy oils such as C heavy oil and tar residue oil are particularly preferred because they are inexpensive. This oil is generally sufficient in an amount of 20% or less of the coal in the coal-water slurry to be treated for mineral removal.

The flotation coal washing method is an existing coal washing method in which a very small amount of oil is added to the pulverized coal-water slurry and stirred to create foam.
Generate floss. Similar to the OA method, in this method, the organic components of the coal adhere to the froth oil film, but the inorganic components are liberated in the water.
This is a method that can separate coal organic components.

The oils used in the flotation method are turpine oil, tar, A heavy oil, C heavy oil, light oil, and kerosene.

Generally, several tens of percent or more of inorganic substances are removed from coal by the above method.

When using coal that has been cleaned in this way, the effect of the additive of the present invention is significantly superior to coal that has not been cleaned, and a coal-water slurry that is several points higher in concentration can be obtained. Furthermore, when cleaned coal is used, in addition to this effect, boiler corrosion during combustion is suppressed, and the burden on ash removal equipment and desulfurization equipment is reduced.

The coal-water slurry thinner of the present invention has a hydrocarbon group of 1
A co-condensate of a sulfonated polycyclic aromatic compound which may be hexa-substituted, a compound having an imino group and/or a compound having a carbamoyl group or a thiocarbamoyl group, and an aliphatic aldehyde or a salt thereof. Contains as an essential ingredient.

Sulfonated polycyclic aromatic compounds that may be substituted with hydrocarbon groups include sulfonated products such as naphthalene, alkylnaphthalene, and anthracene, petroleum sulfonic acid, and lignin sulfonic acid. Among these, sulfonated products of naphthalene and alkylnaphthalene are most preferred.

Examples of compounds having an imino group include guanidine,
Examples include dicyandiamide, biguanide, etc. Compounds having a carbamoyl group or thiocarbamoyl group include urea, alkylene urea, carbamate ester, and their corresponding thio compounds.

Examples of aliphatic aldehydes include formalin, glyoxal, and acetaldehyde. Formalin is generally used.

The thinning agent of the present invention can be produced by known synthetic methods.

That is, a polycyclic aromatic compound which may be substituted with a hydrocarbon group is sulfonated using, for example, sulfuric acid, oleum, or sulfan, and the compound having an imino group is produced as it is or after partial neutralization. A compound having a carbamoyl group or a thiocarbamoyl group and an aliphatic aldehyde are added and co-condensed at a temperature of 60 to 110°C.

The generated condensate is treated with alkali metals such as sodium and potassium, alkaline earth metals such as magnesium and calciumff
i may be made into a salt with ammonia or an amine.

However, the thinning agent of the present invention is not limited by the manufacturing method, and any manufacturing method can be employed as long as the desired thinning agent can be obtained. The degree of condensation is preferably 1.5 to 50. More preferably, a value of 2.0 to 10 is effective.

The reason why the present invention's thinner for coal-water slurry exhibits excellent effects is that after its special structure firmly adsorbs to particles and surfaces, electrostatic factors prevent the particles from agglomerating and form secondary particles. It is thought that liquidity will improve due to stabilization. In particular, imino groups, carbamoyl groups, and thiocarbamoyl groups provide water solubility and are more strongly adsorbed onto particles, so they are thought to exhibit excellent effects never seen before.

As described above, the thinner of the present invention has a condensate with a special structure using a compound having an imino group, a carbamoyl group, or a thiocarbamoyl group as an essential component, and only those having these structures have surprising properties. It is effective.

In addition, if you use clean coal that has been deashed, the effect will be even higher.Due to deashing, the ash, which is highly hydrophilic and has fine particles with a large surface area, is removed. This is because the thinner of the present invention effectively acts on the improved coal surface, thereby making it possible to increase the coal concentration.

The thinner of the present invention can be used for coal-water slurry.
0. ．． 01-5.0 heavy slip%, preferably 003-2.0
Excellent effects can be achieved by adding % by weight. The fluidity limit of a coal-water slurry varies depending on the type and particle size of the coal, but generally, if a thinner is not added, the fluidity will disappear at around 50% coal concentration, but if the thinner of the present invention is added, In case of L, the viscosity decreases significantly, the coal concentration is 61
% or more, especially 70% or more. If cleaner coal is used, the coal concentration increases by several points, generally 3 to 10 points.

The thinner of the present invention can also be used in combination with other surfactants.

Regarding the method for producing coal-water slurry and the method for adding a thinner, there are two methods: dry pulverizing the coal in advance and then mixing the thinner into an aqueous solution, or adding the thinner after making the coal-water slurry. A method of adding coal, water, and a thinner to a mill and mixing it while crushing the coal, and a method of mixing using cleaned coal instead of coal in each method. can be implemented.

The thinner of the present invention has an excellent effect of stably dispersing coal in water, and does not cause water separation even when left standing for a long period of time, for example, one month, and maintains a homogeneous coal-water slurry. There is.

As described above, the thinner of the present invention has a viscosity reduction of 0.0% for coal-water slurry. O1-5.0% by weight, preferably 0.03-2.
By simply adding 0% by weight, the viscosity of coal-water slurry IJ- can be significantly reduced, and a highly concentrated coal-water slurry that can be transported by pump can be produced.

Examples are shown below. In the examples, percentages are based on heavy electric power.

Example 1 20%
Coal pulverized to 0 mesh 80% pass is added at room temperature with stirring to prepare a coal-water slurry of a predetermined concentration. The viscosity of this slurry is measured at 25°C and the fluidity is observed. Furthermore, after this slurry was allowed to stand for one month, the state of water separation was measured.

The test results are shown in Table 2. As shown in Table 2, when the thinner of the present invention is added, even when the viscosity of coal is 72 to 77%, the viscosity decreases to 1. j000 to 3.000 cp, and has extremely good fluidity. On the other hand, when a general anionic surfactant is added or no thinning agent is added, the viscosity becomes 20.000 cp or more at a coal concentration of 50%, and there is no flow at all.

(Left below) Example 2 A clean coal-water slurry of a predetermined concentration is prepared in the same manner as in Example 1 using cleaned coal. The coal particle size is 80% pass of 200 mesh. The viscosity of this slurry is measured at 25°C and the fluidity is also observed.

After this slurry was allowed to stand for one month, the state of water separation was measured.

The thinners of the present invention used in the test are shown in Table 1. The test results are shown in Table 3. As shown in Table 3, when the thinner of the present invention is added to the cleaned coal-water slurry, the viscosity decreases from 1,000 to 3,000 even when the coal concentration is 76 to 80%.
0 cp, and has extremely good fluidity.

On the other hand, when a thinner other than the present invention is added or no thinner is added, the viscosity becomes 20,000 cp or more at a coal concentration of 50%, and no flow occurs at all.

(Leaving space below) Procedural amendment Written by the Commissioner of the Patent Office 1. Indication of the incident 1982 Patent Application No. 135964 2. Invention title Thinning agent for highly concentrated coal-water slurry 3. Relationship with the person making the amendment Patent Applicant Name (350) Daiichi Kogyo Seiyaku Co., Ltd. 4 Agent 5 Notice of Reasons for Refusal ■Date 1928 Month, Day Contents of voluntary amendment as shown in the appendix 1, Thinning agent in Table 1 on page 13 of the specification Type J column: Sulfonated aromatic compound "Butylnaphtholsulfonic acid" is corrected to "Butylnaphthalenesulfonic acid."

Claims (1)

[Scope of Claims] (]) A thinner for highly concentrated coal-water slurries used to reduce the viscosity of coal-water slurries and improve their fluidity and stability, the thinners being substituted with hydrocarbon groups. An essential component is a co-condensate of a sulfonated polycyclic aromatic compound, which may sometimes be used as a sulfonated polycyclic aromatic compound, a compound having an imino group and/or a compound having a carbamoyl group or a thiocarbamoyl group, and an aliphatic aldehyde, or a salt thereof. A high-performance thinner for coal-water slurry, characterized by containing as follows. (2) The high performance thinner for coal-water slurry according to claim 1, wherein the sulfonated polycyclic aromatic compound is naphthalene sulfonic acid or alkylnaphthalene sulfonic acid. (3) The compound having an imino group or a carbamoyl group or a thiocarbamoyl group is selected from urea, thiourea, dicyandiamide, guanidine, biguanide, and derivatives thereof. High performance thinner for coal-water slurries. (4) Claim 1 for use in a coal-water slurry having a coal concentration of 61% or more, preferably 70% or more
A high-performance thinner for coal-water slurry according to any one of items 1 to 3. (5) The high performance thinner for coal-water slurry according to any one of claims 1 to 4, wherein the coal is cleaned coal.