JP3350675B2 - Hazardous substance sulfur solidification sealing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for detoxifying harmful substances by solidifying and sealing with sulfur. More specifically, the present invention relates to a method for solidifying and blocking harmful substances containing an organic chlorine compound such as PCB with sulfur to make the substances harmless. Further, the present invention relates to a method for obtaining a sulfur solidified product obtained by solidifying and blocking a harmful substance as a reusable molded product by molding as required.

[0002]

2. Description of the Related Art As a harmful substance, PCB (polychlorinated biphenyls) has been used as a heat medium or oil for transformers, but because of its high persistence in the environment and extremely high toxicity to the human body, At present, except for a part, use is prohibited. However, environmental pollution due to outflow of PCBs and the like from used and stored waste PCBs has become a serious social problem. To make PCBs harmless, there are a complete incineration method, a hydrothermal decomposition method (supercritical method), a dechlorination method using light or radiation, and a final disposal site for waste PCBs and incinerated ash etc. Measures such as applying a structure are required. Furthermore, it is necessary to detoxify harmful substances other than PCBs, such as organic chlorine compounds, by the same method, or to dispose them at a final disposal site. However, since all of these means require high-cost equipment, it is pointed out that it is necessary to establish a technique for detoxifying these harmful substances at lower cost and easily. Against this background, various studies have been conducted on the solidification and sealing of harmful substances such as organic chlorine compounds such as PCBs. Prevention of elution of harmful compounds and effective use of recycled products, such as civil engineering No satisfactory method has been developed in terms of achieving physical properties that can withstand use as a building material or the like.

[0003]

Accordingly, the present invention provides
It is an object of the present invention to provide a method of solidifying an organic chlorine compound such as PCB and other harmful substances with sulfur to prevent elution of the harmful substances. In addition, the present invention, performance such as strength,
It is an object of the present invention to provide a method for industrially producing a solidified sulfur product having a high quality, no elution of harmful substances, and which can be molded and reused as necessary.

[0004]

That is, the present invention relates to (1) a compound having solubility in a low-polarity solvent which elutes faster than t-butanol when eluted from a silica gel column, and having a boiling point higher than 119 ° C. Triple moisture content of the substance to be treated
% And the raw material mixture containing the substance to be treated and sulfur is lower than the boiling point of the substance to be treated.
Heat-kneading at a temperature of 59 ° C. to prepare a fluid kneaded material under melting of sulfur, and then cooling and kneading the kneaded material, forming it into a predetermined shape as necessary, and solidifying and sealing the substance to be treated. sulfur concrete blockade method of hazardous substances, characterized in, (2) and the steel slag and / or steel dust in which the water content to less than 3% by weight each less than 3 wt% of the water content
(1) The method according to (1), wherein the mixture is heated and kneaded together with the substance to be treated and sulfur, and (3) The method according to (1), wherein the raw material mixture contains an organic chlorine compound and sulfur. Is provided .

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
According to the method of the present invention, a compound (substance to be treated) which is hardly soluble in water, has a solubility in a low-polarity solvent having a solubility in sulfur, and does not volatilize or scatter even by heating and kneading with liquid sulfur. ) Can be solidified and blocked with sulfur.

In the present invention, a solvent that elutes faster than t-butanol when the solvent and t-butanol are eluted from the silica gel column is referred to as a low-polarity solvent. Such low polar solvents include, for example, heptane, hexane, pentane, cyclohexane, trimethylpentane, carbon disulfide, carbon tetrachloride, trichloroethylene, xylene, toluene, benzene in the order of elution (early elution order). , Chloroform, dichloromethane, and diisopropyl ether, and the like,
It is not limited to these. To determine whether a solvent elutes faster than t-butanol, for example, compare the elution time of the solvent in silica gel column chromatography (elution analysis) using silica gel as an adsorbent with the elution time of t-butanol under the same conditions. You can know from that. In order to compare the elution time of a specific solvent with the elution time of t-butanol, the solvent and t-butanol may be simultaneously added to a silica gel column for elution. Alternatively, an elution test for the solvent and an elution test for t-butanol may be separately performed, and the two elution times obtained may be compared. In the elution of the specific solvent and t-butanol, the elution rate can be controlled by using a third solvent or a plurality of solvents separately. In the present invention, the substance to be treated may be heated and kneaded with sulfur in the presence of a solvent, preferably a low-polarity solvent. For example, after the substance to be treated is a solution in a solvent, the resulting solution and sulfur may be mixed,
Further, the solvent can be added to the sulfur before or during the addition of the substance to be treated. The amount of the solvent used is not particularly limited, but is preferably 0.01 to 100 parts by weight of sulfur.
To 100 parts by weight, more preferably 0.1 to 10 parts by weight.
Parts by weight. In addition, in performing the method of the present invention, the addition of such a solvent may be omitted, that is, the heating and kneading of the raw material mixture can be performed without a solvent (low-polarity solvent). In the present invention, a substance to be treated having solubility in a low-polarity solvent that elutes faster than t-butanol when eluted from a silica gel column means that the substance is so-called soluble in the solvent. I do. Here, “soluble” means that the solubility is usually 1000 mg / liter or more (25 ° C.), and preferably the solubility is 2000 mg / liter or more (25 ° C.).
This substance to be treated evaporates and is heated even with liquid sulfur.
In order not to scatter, its boiling point must be at least above 119 ° C, preferably above 159 ° C. Here, the silica gel column means a column filled with silica gel used for column chromatography or thin layer chromatography. As this silica gel, "silica gel 60", "silica gel 60G"
Commercial products such as (trade name) can be used. Also,
If the solvent is more soluble in water, an alumina gel column can be used instead of a silica gel column.

In the present invention, the substance to be treated is easily soluble in sulfur, that is, when the sulfur is dissolved in a certain solvent, the substance has a higher solubility in a solvent having a higher sulfur solubility. Is preferred. In general, solvents that elute faster when eluted from a silica gel column have a higher sulfur solubility. In the present invention, the substance to be treated is heptane, hexane,
It is more preferable that the compound has the above-mentioned solubility in one solvent selected from pentane, cyclohexane, trimethylpentane, carbon disulfide and carbon tetrachloride. Particularly preferred are compounds having the above-mentioned solubility in hexane. Preferably, the substance to be treated does not dissolve in t-butanol. Here, “not dissolved in t-butanol” means that it does not have the above-mentioned solubility in t-butanol. Preferably, the substance to be treated is hardly soluble in water. Here, the poorly soluble means that the solubility in water is usually 100 mg / liter (25 ° C.) or less. t-Butanol can be mixed with water in any proportion. On the other hand, in the elution test from the silica gel column, t
Solvents that elute earlier than butanol (e.g. hexane) are solvents which are hydrophobic, form two layers without mixing with water, have low polarity and can dissolve sulfur. In the present invention, if the compound has solubility in such a low-polarity solvent, the compound itself is soluble in sulfur due to the mutual solubility between the compound, the low-polarity solvent and sulfur. By utilizing the above, the compound (substance to be treated) dissolved in sulfur is solidified and blocked with sulfur.

In the present invention, the raw material mixture containing the substance to be treated and sulfur is heated and kneaded. Here, the substance to be treated may be a simple substance or a mixture of the substance itself, or a mixture of the substance to be treated and another substance, and the form may be either a liquid or a solid. As a raw material containing such a substance to be treated, for example, incineration ash, dust,
Examples include fly ash, waste PCBs from transformer oil, organochlorine pesticides, and the like, or extracts obtained by extracting residues thereof from (contaminated) water or soil. Of these solid raw materials, incinerated ash does not usually contain moisture, but depending on the storage condition, it may be about 5%.
May contain about 3% by weight of water.

In the present invention, as a measure of the water insolubility of the compound, in other words, the affinity between the substance to be treated and sulfur, the solubility in a low-polarity solvent which elutes faster than t-butanol from a silica gel column is used. In addition to satisfying the solubility, the solvent in which the substance to be treated is dissolved preferably has a solvent strength parameter (ε ⁰ ) within a predetermined range. Here, the solvent strength parameter (ε ⁰ ) is a solvent strength when alumina is used as an adsorbent, and has a relationship of ε ⁰ (silica) ≒ 0.77 × ε ⁰ (alumina) [Snyder (LR) .Snyder), Advances
in Analytical Chemistry
& Instrumentation, Rayleigh (C.I.
N. Reilly), Wiley (1964)]. In the present invention, the substance to be treated is a solvent having a solvent strength parameter (ε ⁰ ) of 0.5 or less (for example, heptane (0.01, ε ⁰ value, the same applies hereinafter)), hexane (0.0
1), cyclohexane (0.04), trimethylpentane (0.01), carbon disulfide (0.15), carbon tetrachloride (0.18), toluene (0.29), benzene (0.
32), chloroform (0.40), dichloromethane (0.42), diisopropyl ether (0.28))
It is preferable that the compound has the solubility described above. The solvent strength parameter (ε ⁰ ) is more preferably 0.2 or less, particularly preferably 0.05 or less.
In the present invention, the phrase that a compound has a solvent strength parameter (ε ⁰ ) of 0.5 or less means that the compound is an organic solvent whose solvent strength parameter (ε ⁰ ) is known to be 0.5 or less. It can be confirmed by having the predetermined solubility. This is based on the assumption that, when a compound is dissolved in a solvent, the compound has at least the same solvent strength parameters as the solvent. Thus, in the present invention, the fact that the solvent strength parameter (ε ⁰ ) is a predetermined value does not necessarily mean that the value of the solvent strength parameter (ε ⁰ ) is known for the compound, It means that the solvent strength parameter (ε ⁰ ) measured or confirmed by the above method may satisfy a predetermined condition.

Furthermore, the substance to be solidified and blocked by sulfur has a predetermined solubility in a solvent eluted earlier than t-butanol and also has a dielectric constant (HW).
allmann et al. , Pharmazi
e, 29, 708 (1974)) is preferably 10 or less and / or the dipole moment (calculated by the Debye equation, measured in benzene) is 1.5 or less. The dielectric constant is more preferably 5 or less, and particularly preferably 3 or less. The dipole moment is
It is more preferably 1.3 or less, particularly preferably 0.
It is.

As the substance to be solidified in the method of the present invention, for example, polychlorinated biphenyls (PC
B), polychlorinated terphenyls (PCT), polychlorinated quaterphenyls (PCQ), and polychlorinated dibenzoparadioxins (PCD) such as polychlorinated dibenzofurans (PCDF) and dioxins as dioxins
D), p, p'-dichlorodiphenyltrichloroethane (DDT), p, p'-dichlorodiphenyldichloroethane (DDD), dieldrin, hexachlorocyclohexane (HCH) (benzenehexachloride (BH
Examples thereof include organic chlorine compounds such as C)), but are not limited thereto. In addition to the above, examples of the substance to be treated include organic phosphorus compounds such as parathion, methyl parathion, EPN (nitrophenylphenyl phosphorothionate), and methyldimetone.

In the method of the present invention, the harmful substance itself and also other harmful substances contained in the raw material containing the substance can be sufficiently solidified and blocked by sulfur. Further, by using the aggregate together with the substance to be treated and sulfur, it is possible to impart higher physical strength to the obtained solidified product. The aggregate is not particularly limited, and slag, dust, fine stone, and the like can be used, and preferably are steel slag and / or steel dust. Steel slag and steel dust (so-called steelmaking slag and steelmaking dust) have high iron content and high specific gravity,
By using these, the obtained solidified product also has an advantage that it can have high specific gravity and excellent physical strength. In the method of the present invention, such slag, dust or substances other than the substance to be treated do not have the predetermined solubility in the low-polarity solvent or sulfur, but the steel slag or steel used as the aggregate is used. Dust is also sequestered by sulfur. In other words, steel slag and steel dust usually contain harmful heavy metals such as Pb and As in addition to iron, but these heavy metal species are also blocked by liquid sulfur, and are solidified and, if desired, formed after molding. Does not elute from the solidified product. In addition, the method of the present invention includes:
The contaminated soil and industrial waste are preferably dried and incinerated to reduce the water content to less than 3% by weight.

[0013] The liquefied sulfur exhibits the usual organic solvent behavior. 119 ° C. to 159 ° C. is the temperature range of such liquid sulfur, which becomes yellow, fluid λ sulfur, or brown, viscous μ sulfur depending on the temperature. Sulfur, which is originally a colloidal dispersion system, is known to be completely soluble in hexane and soluble in heptane, pentane, cyclohexane, carbon disulfide and the like. Furthermore, sulfur has a large Clark number of 0.052 (15th place) on the earth. When sulfur is in a liquid state, its polarity is low, so that a substance having a low polarity can be dissolved in liquid sulfur. Furthermore, if there is an organic solvent that can dissolve sulfur and there is a compound that dissolves in the organic solvent,
Sulfur can also be dissolved while the compound is dissolved in the organic solvent in which the compound is dissolved. Such a compound has a small polarity and is insoluble in water, like the above-mentioned organic solvent. However, even if there is no organic solvent, the compound has mutual solubility with sulfur, so that the compound can be dissolved in sulfur. By utilizing this property, PCBs whose outflow and contamination are social issues can be heated and kneaded together with sulfur and uniformly mixed, and then the mixture is cooled to room temperature to solidify the sulfur. Thereby, the PCB taken in the mixture can be solidified and sealed with sulfur. Surprisingly, even if the solidified material obtained in this way is pulverized into a powder having a large surface area, and the powder is dispersed in water and subjected to an elution test, the PCB taken into the solidified material still has The present inventors have found that they do not elute into water. Furthermore, according to the method of the present invention, various compounds including organic chlorine compounds such as PCDF, PCDD (eg, dioxin) and DDT are solidified and sealed, and other compounds having the same structure and physical properties as PCBs. It is thought that it is possible.

Hereinafter, the present invention will be described with reference to the accompanying drawings. FIG. 1 is an explanatory view showing an example of an apparatus for solidifying and closing harmful substances by sulfur according to the present invention. In FIG. 1, 1 is a hopper for steel slag, 2 is a hopper for incinerated ash (the substance to be treated in the present invention or a raw material containing the same), 3
Is a steel dust hopper. Reference numerals 4, 5, and 6 denote measuring tanks for raw materials and aggregates (iron and steel slag, incinerated ash (mixed ash), and steel dust) from the hoppers, respectively. , A movable weighing feeder 7. 21, 22, 23
Is a heating and drying device for raw materials and aggregates other than sulfur, and the heating and drying device is provided with a burner using heavy oil or the like as a fuel and is a heating and drying device such as a rotary kiln. In the heating and drying device, the temperature of the raw materials other than sulfur and the aggregate is set to 120 to
Heat to about 0 ° C. and preferably reduce the water content to 3% by weight
Less than 1.5% by weight, particularly preferably less than 1% by weight. Reference numerals 9, 10 and 11 denote kneaders, and a predetermined amount of the raw material mixture is fed from the feeder 7 to these kneaders. Reference numeral 12 denotes a tank for sulfur as another raw material to be charged into the feeder 7. 13 is an additive tank. The sulfur is heated to a predetermined temperature in the tank 12 and passes through the pipes 14 and 15 to the kneaders 9, 10, 11
Are supplied in predetermined amounts. The tank 12 is provided with a deodorizing device if necessary. Further, additives are appropriately supplied from pipes 16 and 15. Here, the additive is
For example, additives for delaying the curing of sulfur may be mentioned. After the mixture from the feeder 7 and the sulfur and additives from the pipe 15 are charged into the kneaders 9, 10, and 11, kneading is performed.

As for the kneading machines 9, 10 and 11, when selecting a kneading machine type, aggregates (things that act in the same way as aggregates in concrete such as slag, dust, etc.)
The kneader may be selected with an emphasis on taking sufficient time for the molten sulfur to sufficiently penetrate, and may be any type such as a single-shaft, twin-shaft or batch-type, continuous-type, or a batch-type twin-shaft. It is a general practice to use a pug mill type circulating mixer in which the orbits of paddle chips overlap each other to achieve uniform mixing. The kneader used in the present invention needs to adopt a system in which the molten sulfur sufficiently penetrates into the aggregate over as long a time as possible.

However, in the case of the sulfur kneaded product of the present invention, sulfur is hardly oxidized, and the compound or atom is solidified and blocked in the molecule or atom in the sulfur by mixing for a long time ranging from several minutes to tens of minutes. The sulfur can penetrate into the voids of the aggregate, and a high-quality sulfur kneaded product can be produced. If a variable speed device such as an inverter is attached to the kneading machine so that it can easily cope with various types of aggregates, the sulfur kneading material kneading machine can reduce the amount of low-cost, high-quality sulfur with less mechanical wear and power consumption. Can produce kneaded material. More importantly, during mixing the raw materials in the kneader are usually
About 0 ° C., at most about 160 ° C., preferably 115 to 115 ° C.
That is, it must be kept at 140 ° C. Therefore, it is preferable to surround the outer periphery of the kneader with a heat insulating material, and to heat the kneader wall with a heat source such as an electric heater, a heat medium oil, or steam. Further, when treating hazardous wastes, it is necessary to suck dust and harmful gas generated from the inside of the kneader during mixing, so that the inside may be heated in order to prevent a temperature drop due to suction.

As described above, when steel slag or steel dust is used, the order of supply to the kneader can be arbitrarily changed. This makes it easy to respond to changes in the type and composition of the material. Depending on the type and composition of the material, a large amount of sulfur may penetrate into the aggregate during mixing. In such a case, if the necessary sulfur is supplied to the kneading machine at once, the inside of the kneading machine becomes water-like, and it is easy to cause leakage from the seal portion of the shaft and the discharge gate, or the mixture is removed by the mixing blade in the kneading machine. Since the sulfur may be raised, the sulfur is preferably supplied into the kneader in a plurality of times. Materials that promote wear, such as steel slag, may be used for the sulfur kneaded material.Therefore, wear-resistant castings, ceramics, etc. should be used for the mixing blades in the kneader and the kneader case liner. preferable.

In the present invention, the kneader is preferably of a batch type. If the kneading machine is a batch system, there is an advantage that the materials in which the dewatered and heated materials are stored in the heat retaining hopper can be put into the kneading machine in a different order according to the purpose. For example, a method of kneading fine particles of dust and a substance to be treated (such as incinerated ash) with sulfur, and then adding and kneading coarse slag and other waste, fine particle dust,
Coarse-grain slag, a method of adding and kneading sulfur into a mixture of substances to be treated and kneading to complete kneading, a method of adding a substance to be treated, coarse particles, fine particles, and sulfur all at once to complete kneading, and the like. Various dosing sequences can be selected. The penetration of the liquid sulfur into the voids can be performed by adjusting the temperature conditions, the stirring speed, and the residence time during kneading.

In the kneader of the present invention, it is necessary that the liquid sulfur diffuses with affinity to all of the surface layer of the dehydrated and dried solid (preferably, the water content is less than 3% by weight). Therefore, it is important that the mixing time and the temperature of the material are kept within a certain range. That is, since the physical properties of liquid sulfur are 11 cp and 7 cp at 119 to 159 ° C., it is necessary to keep this temperature range. At 159 ° C. or higher, the viscosity rapidly increases, and at 187 ° C., it becomes 10 ⁵ cp, which is close to that of a rubber elastic body. At 119 ° C., it becomes a monoclinic solid, and at 112 ° C., it becomes an orthorhombic form. At room temperature, it becomes the most stable Sα: S ₈ cyclic solid (orthorhombic),
At the time of Sliq → Sα, their coexistence affects the stability and shrinkage of Sα due to the affinity for heavy metals such as Fe and Mn. Regarding the kneading time, if the kneading time is too short, solidification and sealing may be insufficient, and elution of heavy metals such as Pb and Cd may be detected. The kneading time is preferably 10
Longer than 15 minutes, more preferably longer than 15 minutes, more preferably longer than 20 minutes. In the present invention, it is important not to simply embed the raw materials but to completely mix (knead) the raw materials and sulfur to completely block the harmful substances.
Regarding the kneading pressure, in the present invention, kneading is preferably performed under normal pressure or under pressure (including mechanical partial pressurization in the apparatus). According to the invention, not only sulfur but also the blocked organic compounds cannot be extracted from the solidified sulfur with a solvent. In contrast, in the conventional method, raw materials and wastes are extracted by simply dissolving sulfur with a solvent such as carbon disulfide or sulfur monochloride from the product obtained by simply embedding and compressing harmful substances in sulfur. Can be recovered.

In FIG. 1, reference numeral 17 denotes a mobile weighing machine, and reference numeral 18 denotes a cooker truck. The fluid kneaded material prepared by the kneaders 9, 10, and 11 is supplied from the kneader to the mobile sulfur solidified hopper 1
7 to a cooker truck 18. It is discharged and poured into a mold as required, and is formed into a tubular or panel-like shape such as a pile, and if necessary, there is a case where a reinforcing bar or the like is installed inside a molded product or a case where it is solidified into a required shape. On the other hand, in order to take out the crushed stone or sand, an electric screen is provided in the flowing direction of the kneaded material (140 to 120 ° C.), and the particle size is adjusted according to the size of the screen. A device to be charged and solidified (water granulated) can be selected according to the purpose of use of the sulfur solidified product. Similarly, when a movable heat-resistant belt conveyor is provided under the sieve and gradually cooled and solidified for each particle size of a desired shape and size, a slowly cooled sulfur solidified product is obtained.

The case where the cooling and molding of the fluid kneaded material is performed by granulation or slow cooling will be further described. According to the water granulation, the high temperature (140 to 120 ° C.) fluidized kneaded material is rapidly cooled and pulverized to obtain a solidified sulfur having a mass of 50 mm square or less. This granulated sulfur solidified product has a small particle size, and can be reduced in size to the size of a sand particle by further crushing, and its shape is not constant but a shape as seen when coke is cracked. The physical strength of the mass of the solidified sulfur obtained by water granulation is weak, and it can be easily crushed into small aggregates to obtain fine aggregate (sand-like particles: 5 to 0.3 mm). This granulated sulfur solidified material has an irregular particle size and has an uneven outer surface, so that it is very easy to compact when added to sand or gravel, and is suitable as, for example, a landfill material for a beach with a large load resistance. .

On the other hand, according to the gradual cooling, the solidified product after cooling becomes one lump as a whole, and this lump has a high specific gravity and a large physical strength. If this is crushed and the particle size is adjusted, coarse aggregate (40-5m
m) is obtained. Since this gradually cooled sulfur solidified substance has a large physical strength and specific gravity, it can be used as a filling material for a concrete caisson. Furthermore, the solidified sulfur obtained by water granulation or slow cooling can be easily melted in a fluid state by heating it at 120 ° C. or more and 140 ° C. or less as it is or crushed into fine particles. The re-melted sulfur solidified product is easily formed into a predetermined shape such as a cylindrical shape such as a pile or a plate shape by pouring into a predetermined form. On this occasion,
For example, a large-sized product having a small surface area obtained by slow cooling is difficult to be re-melted because it has low thermal conductivity as it is, and it may be necessary to make it into fine particles as described above.

In the present invention, other raw materials that can be mixed with the solidified sulfur include steel slag, steel dust, and industrial waste containing harmful substances. The composition is described in JP-B-62-51440, JP-B-61-15759 and JP-B-61-15759.
No. 2-15274, Japanese Patent Publication No. 2-49680, and the like. Other than the above, there are no particular restrictions on the composition and type (source) of the steel slag and steel dust used in the present invention. According to the present invention, stable solidification can be achieved even if the composition of these raw materials slightly changes. Here, the steel slag means so-called steelmaking slag, and the steel dust means so-called steelmaking dust. Also includes steel dust. The steelmaking slag is an open hearth slag and a converter slag generated in a steelmaking process in an open hearth and a converter. Steelmaking slag usually has a water content of 4-5% by weight. Steelmaking dust (gas ash) is a steelmaking process in open hearth factories, electric furnace factories, etc.
It is a powder that is collected by the dust collector. The composition of steelmaking dust varies depending on the production conditions, but the main component is iron oxide, which contains harmful substances such as Cr, Cu, As, Pb, and Zn. Steelmaking dust usually has a water content of 4 to 10% by weight. An example of the composition of these steelmaking slag and steelmaking dust is shown. In the table, T-Fe is Fe, FeO, Fe ₂
The total iron content in iron-containing components such as O ₃ and FeS is expressed as F
This is a value expressed in terms of e ₂ O ₃ . M-Fe is metal F
Shows e content.

[0024]

[Table 1]

[0025]

[Table 2]

Examples of wastes other than the raw materials used in the present invention include soil contaminated with PCB, DDT, dioxins, heavy metals or other harmful substances, waste containing harmful substances, metal dissolution, and the like. Soot (dust dust) from smelting factories, sludge treated from factory wastewater, incinerated ash from municipal solid waste or industrial waste, crushed processed products of defective products in the electrical product production process, and waste electrical products collected from the market ( Fluorescent lamp,
Pulverized products of batteries and the like). These wastes are usually contained in amounts not to impair the purpose of the present invention, and
An amount of 5 to 95% by weight, preferably 5 to 10% by weight based on the total amount of the substance to be treated and the raw materials such as steel slag and / or steel dust can be used. Table 3 shows examples of these wastes together with the types and amounts of harmful substances contained therein.

[0027]

[Table 3]

The sulfur used as one of the raw materials in the method of the present invention does not necessarily have to be of high purity, but may be by-product sulfur produced as a by-product from the desulfurization process of coke production, iron making, petroleum refinery, etc. Raw elemental sulfur produced may be used. In the present invention, a solidified sulfur is formed from a raw material mixture containing sulfur and a substance to be treated having a predetermined solubility and a boiling point in a low-polarity solvent that elutes earlier than t-butanol. Also,
Further, a sulfur solidified material may be constituted by using a component selected from steel dust, steel slag and other waste together with the substance to be treated and sulfur. Physical properties of the solidified sulfur
The specific gravity varies greatly depending on the difference in the iron content in the aggregate used. For example, when steel dust (steelmaking dust) and / or steel slag (steelmaking slag) is used, the total iron content of the obtained solidified sulfur changes according to the specific gravity of these aggregates, and the specific gravity also changes. In steelmaking dust, the total iron content (T-
Examples of Fe) include open hearth dust of 45 to 68.5% and converter dust of 62 to 63%. In steelmaking slag, although it differs depending on the pretreatment method, examples of T-Fe include 16.5-59% for open hearth slag and 24.6% for converter slag. Regarding steelmaking dust and steelmaking slag, there is a range in the particle size distribution.
The steelmaking slag has a maximum particle size distribution of 0.25 to 4 mm, and has a maximum particle size distribution of 7 to 1 mm.
Since the width of the particle size distribution of the aggregate used has a great effect on the physical strength of the obtained sulfur solidified product, the optimal composition ratio of fine aggregates to coarse aggregates for aggregates such as steel slag and steel dust is determined. Physical strength can be adjusted.
Usually, when using an aggregate having a large particle size distribution,
A sulfur solid having excellent physical strength such as uniaxial compressive strength can be obtained.

Next, the ratio of a raw material other than sulfur to sulfur will be described. In the present invention, the ratio of sulfur to the substance to be treated in the raw material mixture is not particularly limited as long as the substance to be treated is sufficiently solidified and blocked with sulfur. Specifically, the weight ratio between the sulfur and the substance to be treated is (1:
It is preferably about 1 × 10 ⁻⁷ ) to (1: 1 × 10 ⁻³ ). Especially when the substance to be treated is PCB, sulfur and PCB
Is preferably (1: 1 × 10 ⁻⁷ ) to (1: 1 × 10 ⁻⁷ ).
× 10 ^-3 ), and more preferably (1: 1 × 1
^0-7 ) to (1: 5 × 10 ⁻⁴ ), and particularly preferably (1: 1 × 10 ⁻⁶ ) to (1: 1 × 10 ⁻⁴ ). When the substance to be treated is dioxins, the weight ratio of sulfur to dioxins is preferably (1: 1 × 10 ⁻⁷ ) to
(1: 1 × 10 ⁻³ ), and more preferably (1: 1 × 10 ⁻³ ).
× 10 ⁻⁶ ) to (1: 5 × 10 ⁻⁴ ), and particularly preferably (1: 1 × 10 ⁻⁶ ) to (1: 1 × 10 ⁻⁴ ). In the present invention, the ratio of sulfur to the raw material containing the substance to be treated, such as incineration ash or fly ash, is not particularly limited,
What is necessary is just to be in the range which can solidify and block the substance to be treated with sulfur sufficiently. The weight ratio between sulfur and the raw material containing the substance to be treated is preferably (0.5: 9.5) to (8: 2), more preferably (1: 9) to (7: 3), particularly preferably (1: 9). .7: 8.3) to (5: 5).

In the present invention, when aggregates such as steel slag and steel dust are further used, the ratio thereof is not particularly limited as long as the material to be treated can be sufficiently solidified and sealed with sulfur. I just need. When sulfur is 100 parts by weight, the amount of the raw material containing the substance to be treated is preferably 2.5 to 1710 parts by weight, more preferably 4.3 to 8 parts by weight.
It is 10 parts by weight, particularly preferably 10 to 440 parts by weight. On the other hand, the amount of the aggregate is preferably 1710 to 2.5 parts by weight, more preferably 810 to 4.3 parts by weight, and particularly preferably 440 to 1 part by weight with respect to 100 parts by weight of sulfur.
0 parts by weight.

In the present invention, when sulfur, a raw material containing a substance to be treated, steel slag and steel dust are used, their ratio is not particularly limited, and the substance to be treated is sufficiently solidified and sealed with sulfur. May be within the range in which is possible. When the sulfur content is 100 parts by weight, the amount of the raw material containing the substance to be treated is preferably 2.5 to 1710 parts by weight, more preferably 4.3 to 810 parts by weight, and particularly preferably 1 to 10 parts by weight.
0 to 440 parts by weight. The amount of steel slag used is preferably 1700 to 0.02 with respect to 100 parts by weight of sulfur.
5 parts by weight, more preferably 800 to 0.04 parts by weight,
Particularly preferably, it is 435 to 0.1 part by weight. On the other hand, the amount of steel dust used is preferably 0.025 to 1700 parts by weight, more preferably 0.04 to 800 parts by weight, and particularly preferably 0.1 to 43 parts by weight with respect to 100 parts by weight of sulfur.
5 parts by weight. In these raw materials containing a substance to be treated, the ratio of the substance to be treated contained in the raw material to sulfur is preferably within the above range.

In the present invention, in the aggregate kneaded with the molten sulfur, shredder dust is contained in a range that does not impair the properties of the solidified sulfur (for example, about 55% by weight or less in the aggregate,
(Preferably 30% by weight or less)). Shredder dust refers to dust generated when a scrapped vehicle is crushed by a crusher for final treatment and the like, and includes various shapes from crushed materials to dusty ones. The components of shredder dust include resin, rubber, fiber, urethane foam, iron, mercury,
It contains lead, paints, etc., and heavy metals in particular pose a problem in waste disposal.

In addition to the sulfur used, fine powders such as steel slag, steel dust, EP dust (dust collected by an electrostatic precipitator), and dried sludge containing harmful heavy metals (eg, titanium waste slag) are included. Thing may be scattered during the actual processing step. Since these contain harmful substances such as harmful heavy metals, it is necessary to provide a secondary pollution generation and removal device. In this case, as shown in FIG. 2, the raw material 50 is dried by a drier 51, then removed by a cyclone 52, fine powder is removed by a bag filter 53, and finally a three-stage treatment of a wet scrubber 54 for the purpose of deodorization and dust removal. Can be addressed. In the drawing, the portion 55 within the dotted line is parallel or 3 depending on the use for waste such as the substance to be treated, slag, and dust.
A series is provided. In the figure, 56 is a hopper, 57 is a measuring tank,
58 is a mixer. In the figure, the same symbols as those in FIG.

[0034]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. 1) Steelmaking slag: What was called converter ash was used. Grain size: Slowly cooled slag of 4.0 to 0.25 mm (I
DC-C3) Bulk specific gravity: 2.04 g / cm ² T-Fe: 58.8% 2) Steelmaking dust: Particle size: Magnetic separation powder of 1.0 to 0.25 mm (LD-
OB) Bulk specific gravity: 1.82 g / cm ² T-Fe: 59.8% 3) Sulfur: Sulfur is desulfurized sulfur from petroleum refining and has a purity of 99.5.
% Or more was used. Naturally, it does not contain moisture. It is usually heated at 120 ° C. ± 5 ° C. and stored in a liquid state. 4) PCB reagents: The PCB reagents used were four kinds of commercially available PCB standard substances Kane manufactured by GL Sciences Corporation.
chlor KC-300, KC-400, KC-50
0 and KC-600 (trade name), which had different chlorination degrees from each other.

Type of PCB reagent Concentration Trade name (μg / ml) Kanechlor KC-300 651.0 Kanechlor KC-400 603.5 Kanechlor KC-500 534.0 Kanechlor KC-600 594.0

The PCB is soluble in hexane (solubility at room temperature is about 200 mg / liter or more), but is hardly soluble in water. The solubility of PCB in water at 25 ° C. is about 0.3 mg.
Per liter (as a mixture of 3 to 6 chlorine atoms) and about 1 mg / liter even when the chlorine number is low. In addition, PCB has a chlorine number (chlorine number of 3) in the PCB mixture.
６6), the range varies, but about 325 to 420
C. (760 mmHg).

Example 1 900 g of steelmaking slag, 600 g of steelmaking dust, and 555 g of sulfur, each being a dehydrated solid having a water content of less than 3% by weight.
(Total of 2,055 g) in a mixture having a mixing ratio of PCB mixture (Kanechlor KC-300 3.84 m).
1, KC-400 4.14 ml, KC-500
4.68 ml and 4.21 ml of the same KC-600, a total PCB amount of about 10 mg) in a hexane solution (50 m
l) While adding and mixing, heating and evaporating the hexane, keeping the whole temperature at 135 to 145 ° C and continuing mixing and stirring for about 15 minutes or more. After thoroughly mixing, the mixture is poured into water and granulated. A solid (slag) formed. This granulated slag has a specific gravity of 3.2 g / cm ³ and a uniaxial compressive strength of 460 k.
g / cm ² . As a result of testing the dissolution test of PCB from the granulated slag as a measurement certificate (method of measurement, JIS K 0093) according to the notification of the Environment Agency No. 13, the dissolution amount was less than the detection limit value of 0.0005 mg / liter, It was determined that it was not detected.

Example 2 900 g of steelmaking slag, 600 g of steelmaking dust, and 660 g of sulfur, which are dewatered solids each having a water content of less than 3% by weight.
(Total 2,160 g) was kneaded and water-granulated to produce a sulfur solidified product. Separately, the PCB mixture (Kanechlor
KC-300 0.39 ml, KC-400 0.4
1 ml, 0.47 ml of the same KC-500 and the same KC-6
00 0.42 ml) in hexane (50 ml). It was about 1 mg as PCB. A hexane solution of this PCB mixture was added to the sulfur solidified product (granulated product), and heated at 60 to 80 ° C. to evaporate hexane. Furthermore, it is heated to 130 to 140 ° C. to be in a molten state,
After kneading for 0 minutes, the mixture was allowed to cool and solidify at room temperature. This is used as a sample. This sample (slowly cooled solidified product) has a specific gravity of 3.1 g / c.
m ³ , and the uniaxial compressive strength was 440 kg / cm ² . The sample was then ground until the total amount of the sample had a particle size that passed through a 2 mm sieve. The sample that passed through the sieve was added to a 10-fold amount of pure water (pH 5.8 to 6.3) to prepare a sample solution. This sample solution was shaken by the following shaking operation. Shaking frequency, 200 times per minute; shaking width, 4 cm or more and 5 cm or less; shaking time, 6 hours. After the sample solution shaken by the shaking operation was allowed to stand for about 10 to 30 minutes, the supernatant was centrifuged at about 3,000 rpm for 20 minutes, and then the supernatant was filtered through a 0.45 μm membrane filter. The sample was used as a test solution. The test solution obtained as described above was subjected to a PCB dissolution test. As a result of the dissolution test, the dissolution amount is less than 0.0005 mg / liter (less than the detection limit).
Met.

Example 3 1500 g of steelmaking slag and 500 g of steelmaking dust, each of which is a dehydrated solid having a water content of less than 3% by weight, and 410 g of sulfur,
And a sulfur solid was produced by water granulation. Separately prepared PCB mixture (Kanechlor KC-30
0, KC-400, KC-500 and KC-60
0, 5 ml each, 20 ml in total, about 11.9 in total as PCB
hexane solution (50 ml) was added to the sulfur solidified product and heated at 60-80 ° C. to evaporate hexane.
Further, it is heated to 130 to 140 ° C. to be in a molten state,
After kneading for 0 minutes, the mixture was allowed to cool and solidify at room temperature to obtain a sample. This sample (slowly cooled solidified product) had a specific gravity of 3.2 g / cm ³ and a uniaxial compressive strength of 640 kg / cm ² . This sample was subjected to the same treatment and dissolution test as in Example 2. As a result of the dissolution test, the dissolution amount was less than 0.0005 mg / liter (less than the detection limit).

Example 4 500 g of sulfur was mixed with a PCB mixture (Kanechlor).
A hexane solution (50 ml) of KC-300, KC-400, KC-500 and KC-600, 5 ml each, a total of 20 ml, and a total of about 11.9 mg as PCB) was added. Then, the mixture is heated at 60 to 80 ° C. to volatilize hexane, and further heated to 130 to 140 ° C. to be in a molten state,
After kneading for about 10 minutes, the mixture was allowed to cool and solidify at room temperature to obtain a sample. This sample (slowly cooled solidified product) has a specific gravity of 1.9 g / cm.
^{3. The} uniaxial compressive strength was 20 kg / cm ² . This sample was subjected to the same treatment and dissolution test as in Example 2. As a result of the dissolution test, the dissolution amount was less than 0.0005 mg / liter (less than the detection limit).

Example 5 500 g of sulfur was added to a PCB mixture (Kanechlor).
KC-300, KC-400, KC-500, and KC-600, 10 ml each, a total of 40 ml, and a hexane solution (50 ml) of a total of about 23.7 mg of PCB) were added in the same manner as in Example 3 except that a hexane solution (50 ml) was added. To obtain a sample. This sample (slowly cooled solidified product) had a specific gravity of 1.9 g / cm ³ and a uniaxial compressive strength of 20 kg / cm ² . As a result of the treatment and the dissolution test performed in the same manner as in Example 3, the dissolution amount was less than 0.0005 mg / liter (less than the detection limit).

COMPARATIVE EXAMPLE 1 300 g of steelmaking slag and 200 g of steelmaking dust were mixed, heated and dried to obtain a powder having a water content of less than 3% by weight.
B mixture (Kanechlor KC-300, KC-300)
-400, KC-500 and KC-600, 5m each
1, a total of 20 ml, a total of about 11.9 mg of PCB) in hexane (50 ml) was added. Then, 60-8
After heating at 0 ° C. to volatilize hexane, further heating to 130 ° C. and mixing for 10 minutes, the mixture was allowed to cool and solidify at room temperature to obtain a sample. This sample (powder) has a specific gravity of 2.2 g / cm.
^{Was 3} . This sample was subjected to the same treatment and dissolution test as in Example 2. As a result of the dissolution test, the dissolution amount was 0.1.
It was less than 0005 mg / liter (below the detection limit).

COMPARATIVE EXAMPLE 2 300 g of steelmaking slag and 200 g of steelmaking dust were mixed, heated and dried to obtain a powder having a water content of less than 3% by weight.
B mixture (Kanechlor KC-300, KC-300)
-400, KC-500 and KC-600, 10 each
A hexane solution (50 ml) was added, which was 40 ml in total, and about 23.7 mg in total as PCB. Next, a sample was obtained in the same manner as in Comparative Example 1. This sample (slowly cooled powder)
Had a specific gravity of 2.2 g / cm ³ . Comparative Example 1
As a result of the same treatment and dissolution test as described above, the dissolution amount was 0.003 m
g / liter (detection limit 0.0005 mg / liter)
As PCB.

From the above results, it can be seen that PCB was completely solidified and sealed in the solidified product obtained using sulfur, steelmaking slag, and steelmaking dust according to the method of the present invention (Examples 1, 2, and 3). Similarly, it was found that the solidified product obtained by using sulfur according to the method of the present invention completely blocked the PCB (Examples 4 and 5). In contrast, when using steelmaking slag and steelmaking dust without using sulfur,
When the amount of added PCB was small, solidification and sealing could be performed (Comparative Example 1), but when the amount of added PCB was large, PCB was eluted without being blocked (Comparative Example 2). From Comparative Examples 1 and 2, even if sulfur was not used, according to the steelmaking slag and steelmaking dust used as the auxiliary material in the method of the present invention, the blockade was achieved by incorporating PCB into the pores. However, it can be seen that when the amount of PCB increases, the PCB is eluted without being blocked.

Example 6 900 g of steelmaking slag, 600 g of steelmaking dust and 660 g of sulfur, each of which is a dehydrated solid having a water content of less than 3% by weight.
(Total 2,160 g) is kneaded and water-granulated to produce a solidified sulfur product. Separately, dioxin standard substances (2, 3, 7,
Prepare a 1 mg toluene solution (as an equivalent of 8-T ₄ CDD (TEQ)). This dioxin toluene solution is added to the sulfur solidified product (granulated product), and 100 to 11
Heat at 5 ° C. to evaporate the toluene. In addition, 130
The mixture is heated to about 140 ° C. to be in a molten state, kneaded for about 10 minutes, and then cooled and solidified at room temperature. This is used as a sample. This sample is treated in the same manner as in Example 2, and a dioxin elution test is performed. Dioxins are not detected by the dissolution test.

Example 7 To 500 g of sulfur, a toluene solution (50 ml) of 10 mg of dioxins is added. Then 100-115 ° C
To evaporate the toluene, and further 130-140
C. to obtain a sample by heating to a molten state, kneading for about 10 minutes, and then cooling and solidifying at room temperature. This sample is treated in the same manner as in Example 5, and a dioxin elution test is performed. As a result of the dissolution test, the dissolution amount was below the detection limit.

Comparative Example 3 900 g of steelmaking slag, 600 g of steelmaking dust, and 660 g of sulfur, which are dehydrated solids each having a water content of less than 3% by weight.
From the total (2,160 g), a sulfur solidified product was produced by water granulation in the same manner as in Example 1. Separately, diethylene glycol 1
A dispersion of 0 mg of hexane (100 ml) was prepared.
The diethylene glycol hexane dispersion solution was added to the sulfur solidified product (granulated product), and heated at 60 to 80 ° C. to volatilize hexane. Further, the mixture was heated to 130 to 140 ° C. to be in a molten state, kneaded for about 10 minutes, and then allowed to cool and solidify at room temperature. This is used as a sample. About this sample,
The same treatment as in Example 1 was performed, and a dissolution test was performed on diethylene glycol. As a result of the dissolution test, 3 mg / liter of diethylene glycol was detected. Here, diethylene glycol is benzene, toluene, carbon tetrachloride,
Insoluble in low polar solvents such as chloroform, soluble in solvents (not low polar) such as water, alcohols, ethers, and acetone, and freely miscible. The boiling point of diethylene glycol is 245 ° C (133 ° C / 14m
mHg).

[0048]

According to the present invention, substances such as harmful organic chlorine compounds such as PCBs, which had no effective solid sealing means, can be solidified and sealed very effectively with sulfur.
In particular, steel slag and steel dust are used together as auxiliary materials,
By appropriately molding, a solidified sulfur product having extremely high specific gravity and high strength and which can be used as a ballast material or the like can be obtained. As described above, the present invention has remarkable significance in terms of prevention of environmental pollution, and further, regeneration and utilization of resources.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an example of a sulfur solidifying and sealing apparatus for harmful substances suitable for carrying out the method of the present invention.

FIG. 2 is an explanatory view of another example of a sulfur solidification sealing device for harmful substances.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel slag hopper 2 Incineration ash hopper 3 Steel dust hopper 4 Iron and steel slag measuring tank 5 Incineration ash (condensed ash) measuring tank 6 Iron and steel dust measuring tank 7 Mobile measuring feeder 9, 10, 11 Kneader Reference Signs List 12 tank 13 additive 14, 15, 16 pipe 17 mobile sulfur solidified hopper 18 cooker 21, 22, 23 heating and drying device

Continuation of the front page (72) Inventor Takuya Yamato 4-33-8 Kuramae, Taito-ku, Tokyo Inside Ikari Environmental Research Institute Co., Ltd. (56) References JP-A-4-122270 (JP, A) JP-A 2001-25752 ( JP, A) JP-A-58-178185 (JP, A) JP-A-8-318244 (JP, A) JP-B-62-151440 (JP, B2) JP-B-2-49680 (JP, B2) (58) ) Field surveyed (Int. Cl. ⁷ , DB name) B09B 3/00-5/00

Claims (3)

(57) [Claims] 1. A water-containing substance having a solubility in a low-polarity solvent eluted earlier than t-butanol when eluted from a silica gel column and having a boiling point higher than 119 ° C.
The amount of the substance to be treated and the raw material mixture containing sulfur are lower than the boiling point of the substance to be treated.
Heat-kneading at a temperature of 19 to 159 ° C. to prepare a fluid kneaded material under melting of sulfur, and then cooling the kneaded material,
A method for solidifying and sealing a harmful substance, comprising forming the substance to be treated in a predetermined shape if necessary. 2. An iron or steel slag and / or steel dust each having a water content of less than 3% by weight , said water content being 3% by weight.
The method according to claim 1, wherein the mixture is heated and kneaded together with the substance to be treated and sulfur, which are less than 10% . 3. The method according to claim 1, wherein the raw material mixture contains an organic chlorine compound and sulfur.