JPH0693928B2 - Immobilization treatment method for liquid organic halides - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for treating a liquid organic halide such as PCB into a solidified form suitable for landfill treatment.

[Prior Art] Today, use of liquid organic halides such as PCB (polychlorinated biphenyl) is prohibited due to its strong toxicity. Therefore, it is desired to discard all the liquid organic halides currently owned by each company, but it is difficult to treat them due to their extremely high stability.

Therefore, in the past, in addition to being temporarily stored in large quantities in a drum or transformer container as a provisional process,
Some methods of incineration at high temperature, such as spray incineration or incineration after pulverization, have been adopted.

[Problems to be Solved by the Invention] However, in the former storage method, there is a possibility that the contents may flow out due to corrosion of the container with the passage of time or due to a natural disaster such as an earthquake. In addition, even in the latter method of incineration, it is carried out at a high temperature exceeding 1000 ° C, so the cost required for processing equipment and processing costs is enormous, and when incomplete combustion occurs, harmful gas such as dioxin is generated. There is a risk of environmental damage due to the occurrence.

In addition, transportation of liquid organic halides is permitted when sealed in a container, but this does not mean that a sudden accident such as a traffic accident will not occur.In this case, the liquid organic halides will not be transported to the outside. The spill could also cause unpredictable environmental pollution.

Further, conventionally, a technique for solidifying a liquid organic halide into a powder state by mixing and solidifying with slag dust, calcium carbonate, etc. has been established, but this solid state product is a liquid organic halide at room temperature. There is a possibility of a slight evaporation,
Moreover, since it is powdery, it may be scattered.

Therefore, an object of the present invention is to provide a treatment method capable of obtaining a solidified form of a liquid organic halide suitable for landfill disposal in a natural environment.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has the following constitution regarding a method for fixing a liquid organic halide.

That is, for liquid organic halides, slag dust accompanying metal refining containing at least activated alumina, quick lime, magnesium oxide and manganese oxide, silicates, organic acid metal salts, calcium carbonate, and water-soluble polymers. , And a process of mixing with water to form a solid, a process of mixing the solidified product with sulfur, and a process of heating the mixture under stirring to maintain a temperature equal to or higher than the melting point of sulfur. It is characterized by

In the above-mentioned constitutional feature of the present invention, the liquid organic halide to be treated includes PCB, TCB, and various organic halogen liquids.

The slag dust is emitted from the metal refining business,
Table 1 below shows an example of the specific composition of the components and the content ratio of the components.

As the silicate, sodium silicate, calcium silicate, magnesium silicate, calcium / sodium silicate or the like can be applied. Examples of the organic acid metal salt include stearic acid residue, capric acid, lauric acid, myristic acid, palmitic acid, linoleic acid, linolenic acid, and higher fatty acids such as oleic acid, or benzoic acid, p-hydroxybenzoic acid, salicylic acid, and naphthoic acid. A salt of an aromatic carboxylic acid such as acid or tannic acid and a metal such as aluminum, manganese, cobalt, calcium, magnesium, iron, zinc or nickel can be applied. Examples of the water-soluble polymer include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxycellulose, methylcellulose and ethylcellulose, sodium polyacrylate, acrylic acid amide / acrylic acid ester copolymer, alginic acid. Soda, gelatin, casein, etc. can be applied.

In the present invention, the compounding ratio of each of the above-mentioned components when the liquid organic halide is solidified is shown in Table 2 below.

The mixing order of the above-mentioned components for solidification is arbitrary. Further, bentonite, porcelain clay and the like can be additionally mixed as an extender with respect to this compounding component. Further, the above-mentioned solidified component is mixed in a ratio of 50 to 200 parts by weight with respect to 100 parts by weight of the liquid organic halide.

Further, water is mixed when the liquid organic halide is solidified. In this case, preferably, the solidifying component is a method of mixing water in advance after uniformly mixing with the liquid organic halide, but the time of mixing the water can be changed, and the liquid organic halide, Alternatively, the solidifying component and water may be mixed in at the same time.

Further, a solidified product of a liquid organic halide is obtained by the solidification process described above. The sulfur is preferably amorphous or crystalline solid sulfur that can be mixed with the solid material, and particularly powdery or granular material from the viewpoint of homogenizing the mixing with the solid material. It is also possible to use sulfur. When using the massive sulfur, it is also possible to melt it in advance and mix and stir the solidified product in this.

The heating of the mixture of the solidified substance and sulfur is performed within a temperature range of 119 ° C to 180 ° C. In addition, 119
C is the melting point of sulfur, and around 180 C is the boiling point of liquid organic halides such as PCB. Therefore, heat treatment that maintains the temperature in the range of 130 ° C to 150 ° C is a suitable condition.

The solid form of the liquid organic halide obtained by the above-mentioned treatment method depends on the mixing amount of sulfur, that is, when the mixing amount of sulfur is relatively small, for example, 30% by weight, it is powdery or granular. It is obtained in the form of a lump, and when it is relatively high at 40% by weight, it is obtained in the form of a block.

In addition, after the above-mentioned heat treatment process, a process of pelletizing the processed product is added to prepare a processed solid of a certain size. The pelletizing process in this case is, for example, mixing the powdery or granular treated material with an aqueous solution of a water-soluble polymer such as CMC (sodium cellulose glycolate) to form a slurry, which is then formed into a regular shape and dried. It can be performed by a general method such as.

[Operation] The operation of the treatment method of the present invention is as follows.

First, in the process of solidifying a liquid organic halide,
Calcium oxide and magnesium oxide in the slag dust are converted to calcium hydroxide and magnesium hydroxide solids by the provision of hydroxyl groups from the water-soluble polymer substance. Organic halogen is adsorbed on the porous portion of the solid and silicate. On the other hand, at the same time, in the silicate, the silane is released and monosiloxane is generated in association with the Gerenite reaction. In monosiloxanes, silane is released to replace one of the positions with an alkyl group from the organic acid metal salt, and the other one to take in and stabilize chloride ion. The solution is in an exothermic state during the hydration reaction of calcium oxide and magnesium oxide. This heat causes the solution to reach about 120 ° C.
Temperature rises in the range of ~ 150 ℃. This monosiloxane is condensed upon cooling to be synthesized as an organohalopolysiloxane, and calcium hydroxide and magnesium hydroxide are coated on the surface of this synthetic product. This organohalopolysiloxane and other compounding ingredients such as activated alumina, manganese oxide, and other non-ionic muddy substances in the slag dust component form a paste-like hydrate in the presence of water. Further, during the hydration reaction, the hydrate is converted into a pozzolanic reaction product by the reaction between the silicate component and the calcium compound. The pozzolanization reaction product itself is insoluble in water, and the liquid organic halide is fixed in the pozzolanization reaction product. The solid material treated in this way is obtained as a powder or powder.

Then, sulfur is mixed with the solidified substance, and in the process of heating the mixture at a melting temperature of sulfur or higher, the sulfur is melted and the surface of the solidified substance is coated. The treated product thus coated with the sulfur film is obtained as a powdery or granular or lumpy substance, and has a strong water-insoluble state. At the same time, the sulfur that has undergone the above heating process raises the ignition temperature in combination with the coating form of the solid material and makes it flame-retardant. Further, this treated product has a strong property.

[Examples] (Example 1) Trans oils having the component ratios shown in Table 3 below were treated by the following process.

First, in the first step, solidification treatment for 100 g of this transformer oil was carried out as follows.

Each component for solidification shown in Table 4 below was sequentially mixed with trans oil under normal temperature in a stirring state.

The above-mentioned slag dust was discarded due to metal refining, and the components contained are as shown in Table 5 below.

In this mixing process, the temperature of the mixture rose to a maximum of 162 ° C in the muddy state, but the temperature decreased to room temperature after 7 minutes in the agitated state, and a powdery or granular solidified product was obtained. It was

Then, as a second and third step, the solid compound 10
30 g (30% by weight) of crystalline powder was mixed with 0 g and uniformly mixed, and the mixture was heated and mixed and stirred under a constant temperature condition of about 130 ° C. for about 2 minutes. During the mixing process, the color of the mixture turned yellow. Then, it was naturally cooled to room temperature (30 ° C).

The treated product thus obtained was in the form of a dry powder, and the sulfur solid was once melted in the heating step described above and was in a coating state on the surface of the solidified product. It was confirmed.

Using this treated product as a sample, the following dissolution test was carried out according to the test method of Notification No. 13 of the Environmental Agency. That is, the above sample was immersed in a liquid of water or an aqueous solution shown in Table 6 below, stirred for 6 hours and filtered, and the filtrate was extracted with acetone, and the extract was concentrated. The amount of halide produced was measured. The measurement results are as follows.

Thus, the measurement results were all below the detection limit, and no elution of the organic halide was observed.

(Example 2) The same trans oil as in Example 1 was solidified in the same manner as described above, and 100 g of the obtained powdery or granular solidified product was added to 40 g (40 g) of crystalline powdered sulfur. (% By weight)
Was mixed and uniformly mixed, and the mixture was heated and continuously mixed and stirred under a constant temperature condition of about 130 ° C. for about 3 minutes.
Then, it was naturally cooled to room temperature.

In the heating process described above, the sulfur solid was once melted, and became a lump in a state in which the powder or granules of the solid material were individually wrapped.

Using this treated product as a sample, a dissolution test was conducted according to the Environmental Agency Notification No. 13 in the same manner as above, and the results are shown in Table 7 below.

(Example 3) 100 g of the powdery or granular processed material obtained in Example 1
To this, 50 ml of an approximately 1% aqueous solution of CMC was added, mixed and stirred to form a slurry, and this slurry was fed into a dragonfly having about 100 holes (diameter 2 mm). Then, the linearized product of the slurry flowing down from each of the above-mentioned perforations was successively cut into pieces each having a length of about 30 cm to 100 cm and received in the receiver at the lower position. Then
20 minutes to 3 in a dryer with internal temperature set to 100 ° C
After drying for 0 minutes, a pelletized product was obtained.

The results of the elution test of the pelletized product according to the Environmental Agency Notification No. 13 are also shown in Table 8 below, and no elution of the organic halide was observed.

[Effects of the Invention] Since the present invention is configured as described above, the following effects are achieved.

First, the treated product of the liquid organic halide obtained by the method of the present invention is almost completely insoluble in the organic halide even in the strongly acidic water or the strongly alkaline water and the seawater, which are severe conditions in the natural environment. With
Since sulfur is also made flame-retardant, it can be landfilled as it is or in the state of being stored in a can container or the like.

In addition, the coating form of sulfur with respect to the solid form is physically added with the action of preventing the volatilization of the liquid organic halide, so that the safety can be ensured during the transportation and after the above landfill disposal.

In addition, the above-mentioned landfill disposal is particularly advantageous in that the present invention uses slag dust that is industrial waste, that the treatment is extremely simple such as mixing operation, and that heat treatment at a relatively low temperature is sufficient. On the other hand, there is an advantage that it can be implemented at an extremely economical processing cost as a whole.

Moreover, when pelletizing the obtained processed product to a certain shape and a certain size, it is possible to prevent scattering during transportation and landfill work, and to prevent movement and outflow from the landfill site after landfill. it can.

Claims (3)

[Claims] 1. A slag which is a slag, which is produced by refining a metal and contains at least activated alumina, quick lime, magnesium oxide and manganese oxide with respect to a liquid organic halide.
Organic acid metal salt, calcium carbonate, water-soluble polymer,
And a step of mixing with water to form a solid, a step of mixing the solidified product with sulfur, and stirring the mixture under stirring.
A process for immobilizing a liquid organic halide, comprising the step of heating so as to maintain a temperature of 9 ° C to 180 ° C. 2. Sulfur is 30 to 40 relative to the solid compound.
The method for immobilizing a liquid organic halide according to claim 1, wherein the liquid organic halide is mixed in a weight ratio. 3. The method for immobilizing a liquid organic halide according to claim 1, further comprising a step of pelletizing the mixture after the heat treatment.