JPS624200B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a muddy water treatment agent that promotes solid-liquid separation, agglomeration, and hardening of muddy water.

When the present inventors added a novel sludge treatment agent consisting of cement, a nonionic polymer, and an anionic polymer to muddy water in powder form, the polyvalent metals in the cement complexly formed hydrates. The presence of this hydrate promotes the solid-liquid separation effect based on the cross-linking adsorption and compaction of the anionic polymer, and the presence of the nonionic polymer makes it possible to obtain aggregates with low water-holding properties. They also discovered that this product did not return to its original state as sludge even if it was reconstituted with water after dehydration, and they filed a patent application for this (Japanese Patent Application No. 14610-1981).

However, when the sludge treatment agent of this invention is added to highly viscous sludge, such as organic clay that does not contain sand or silty clay that contains carboxymethyl cellulose, the elution rate of anionic and nonionic polymers slows down. As a result, it takes time for the reaction to complete, and in order to speed up the reaction completion, large amounts of expensive anionic and nonionic polymers must be added, and as a result, these chemicals sometimes remain unreacted in the sludge. Sometimes it remained as is.

As a result of further investigation into this sludge treatment agent, the present inventors found that when powdered granulated slag is added to this sludge treatment agent and added to the sludge, anionic polymers and nonionic polymers are produced even in highly viscous sludge. It is rapidly eluted, and a multidimensional complex reaction occurs between the cement, nonionic polymer, anionic polymer, granulated slag, and sludge material, and solid-liquid separation, agglomeration, and hardening of the sludge are performed smoothly. Based on this knowledge, we have completed the present invention.

The mud water treatment agent of the present invention is characterized in that it is made by adding powdered granulated slag to cement, powdered nonionic polymer, and powdered anionic polymer.

Examples of cement include various boltland cements, blast furnace cements, silica cements, flyash cements, alumina cements, and mixtures thereof.

Nonionic polymers include polyethylene oxide, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, and the like, and preferably have a molecular weight of 4 million or more. Examples of the anionic polymer include sodium polyacrylate, partial hydrolyzate of polyacrylamide, and sodium polystyrene sulfonate, and those having a molecular weight of 6 million or more are preferred.

The nonionic polymer and anionic polymer are 0.2 to 0.8% by weight and 0.7 to 1.2% by weight, respectively, in the muddy water treatment agent.
Preferably, it is % by weight.

As the granulated slag, granulated blast furnace slag, nonferrous metals, refined slag, and ferroalloy slag are used. The amount added is not limited, but it is preferably 0.5 to 3 times the weight of cement.

Mud water treatment using the mud water treatment agent of the present invention is carried out by adding an appropriate amount of the mud water treatment agent obtained by mixing the above four components to mud water, followed by stirring and filtering.

The amount of muddy water treatment agent added to muddy water varies depending on the solid content in the muddy water, but usually
The standard amount is 0.05 to 1.5% by weight. When adding the muddy water treatment agent to muddy water during stirring, first stir the mixed composition rapidly, wait for a moment to see where aggregates have formed, and then stir slowly to remove aggregates. It is preferable to encourage the growth of

Although the reaction of the muddy water treatment agent of the present invention to muddy water could not be elucidated theoretically, the use of granulated slag facilitates the elution of the high molecular weight polymer added at the same time, and at the same time, the reaction between cement and granulated slag The metal ions and soluble silicic acid contained in the cement combine to form a hydrate different from that of cement alone, which aggregates and synergistically doubles coagulation and hydrophobization when combined with anionic and nonionic polymers. It is thought that this will lead to solid-liquid separation.

According to the present invention, the method for preparing the muddy water treatment agent is simple, and since the obtained muddy water treatment agent is in the form of powder, it is convenient to handle and transport.

Further, according to the present invention, since the elution rate of anionic polymer and nonionic polymer to muddy water is high, the consumption of nonionic polymer, anionic polymer, and cement can be reduced for the same level of muddy water treatment.

Further, according to the present invention, it is possible to easily treat even viscous muddy water to be treated, such as muddy sludge from civil engineering construction sites, which contains CMC (carboxymethyl cellulose) and the like.

Next, the present invention will be explained with reference to examples. % and parts in the text indicate weight % and parts by weight unless otherwise specified.

Example 1 The muddy water treatment agent contains 69.2 parts of granulated blast furnace slag, 29.6 parts of ordinary cement, 0.8 parts of partial hydrolyzate of polyacrylamide (molecular weight: 10 million, hydrolysis rate: 25%), 0.8 parts, polyethylene oxide (molecular weight: 4 million, intrinsic viscosity: 150 cps), 0.4 parts.
Each portion was placed in a tube mill, mixed and ground by rotational stirring for 30 minutes, and then used.

The muddy water was discharged during underground wall construction, and the SS concentration was 18% (approximately 5% bentonite, 0.6%
cement containing 7% sand) was used.

This muddy water 1 was taken in a beaker, 1% of the muddy water treatment agent was added to the muddy water, and the mixture was initially stirred at a circumferential speed of 26 m/min for 20 seconds, and then continued at a circumferential speed of 13 m/min. The muddy water was separated into solid and liquid in about 1 minute and 5 seconds after starting.
Further stirring was continued for 2 minutes and 15 seconds at a circumferential speed of 13 m/min, and the separated mud was aggregated. The diameter of the aggregated separated mud was approximately 7 mm or more, and the larger one was 27 mm.
It also reached When this agglomerated mud was placed on a screen with a mesh spacing of 1 mm to a thickness of about 30 mm and subjected to gravity filtration, the water ran off in 1 minute and 12 seconds and it became agglomerated material with a moisture content of 60%, which could be easily removed from the screen. It peeled off. On the other hand, the water separated during solid-liquid separation has a transparency of 30 or higher SS
The concentration was 36 ppm.

Comparative Example 1 98.8 parts of ordinary cement, 0.8 parts of the partial hydrolyzate of polyacrylamide used in Example 1, and 0.4 parts of polyethylene oxide were each calculated and charged into a tube mill, mixed and ground by rotary stirring for 30 minutes. was used.

When the muddy water used in Example 1 was treated in the same manner as in Example 1, solid-liquid separation occurred approximately 3 minutes after the start of stirring, and agglomeration occurred in 2 minutes 50 seconds after solid-liquid separation.

The diameter of the aggregated mud was 9 to 34 mm. The subsequent draining effect was almost the same as in Example 1.

That is, when cement was blended with polyacrylamide and polyethylene oxide, it took more than twice the time to reach solid-liquid separation with the same amount used than when cement, granulated blast furnace slag, polyacrylamide, and polyethylene oxide were blended. From this,
When granulated blast furnace slag is added to cement, it is expected that the viscosity of the mud will be lowered and polyethylene oxide and polyacrylamide will be better leached into the mud.

Example 2 The waste mud after being used in the underground wall construction method has a relatively low water content of 89%, but it contains about 0.2% CMC, so it is quite viscous, which is the customary method for this type of mud water treatment. If only a partial hydrolyzate of acrylamide, such as a polymer flocculant, is provided, solid-liquid separation will not occur easily.

This muddy water 1 was poured into a beaker 1 according to Example 1.
The muddy water treatment agent of the present invention used in Example 1 was added to this muddy water at 1.5% to the muddy water, and the initial
Stir for 30 seconds at a circumferential speed of m/min and then continue to stir for 13 seconds.
Stirring was continued at a circumferential speed of m/min, and the slurry separated into solid and liquid approximately 1 minute and 30 seconds after the start of stirring. When stirring was further continued at a circumferential speed of 13 m/min, agglomeration was achieved in 3 minutes after solid-liquid separation.
The agglomerated separated mud had a diameter of 10 mm or more, and some as large as 35 mm. When the agglomerated mud was placed on a screen with a mesh spacing of 1 mm to a thickness of about 30 mm and subjected to gravity filtration, it passed for 1 minute 20 minutes. The water ran off in seconds, forming agglomerates with a moisture content of 60%, which were easily peeled off from the screen.

On the other hand, the water separated during solid-liquid separation has a transparency of 30 or higher.
The SS concentration was 25 ppm.

The obtained agglomerates were completely shaped, and the unconfined compressive strength was 0.4 Kg/cm ² after one day, and 1.5 after 3 days.
The hardness reached Kg/ ^cm2 .

Comparative Example 2 The muddy water treatment agent used in Comparative Example 1 was added to the highly viscous muddy water containing CMC used in Example 2, resulting in almost the same result as when the muddy water treatment agent of the present invention shown in Example 2 was used. When trying to obtain the effect, in Example 2, the amount of processing agent used was 1.5%, but it required more than 3% or about 4%, but it was still somewhat inferior to Example-2 in terms of time to solid-liquid separation. It was found that about 5% is required to reliably match the time required to achieve solid-liquid separation equivalent to that in Example 2. The unconfined compressive strength of the molded product after one day was 0.3 Kg/cm ^{2 ,} and the strength after 3 days was 1.2 Kg/cm ² .

Claims (1)

[Claims] 1 A muddy water treatment agent consisting of cement, powdered anionic polymer, powdered nonionic polymer, and powdered granulated slag.