JPWO2010055830A1 - Method for treating metal-containing particles - Google Patents

Abstract

It is an object to provide a method for detoxifying particles containing metals including harmful heavy metals and needle-shaped particles, particularly waste particles, in an extremely safe, simple and inexpensive manner. The objective is to provide a treatment method that can sustain the effect of treatment over time and prevent secondary pollution, and a treatment method that also contributes to resource recycling. Furthermore, heat resistance; flame retardancy; acid, alkali, organic Chemical resistance to solvents, etc .; antistatic properties; weather resistance; to obtain composite particles excellent in water repellency, etc. at a relatively low cost. The above problem was solved by a particle processing method characterized in that after impregnating the particles containing bismuth, the particles were heated and melted at a furnace temperature of 600 ° C. or higher.

Description

  The present invention relates to a method for treating particles containing metals, and more particularly to a method for treating particles containing metals, characterized by heating after impregnating a specific treatment solution. It is.

  In recent years, waste generated from cities, factories, and the like has increased, and the importance of detoxifying the waste has increased. Among them, waste containing heavy metals is a special management waste, and strict regulations are provided for its treatment and disposal, and detoxification treatment is indispensable.

  Conventionally, when disposing of wastes containing heavy metals, a method of mixing with cement and adding and kneading water as necessary to prevent elution of heavy metals has been adopted. However, in the method using cement, stabilization of heavy metals is not sufficient, and there is a problem in sustainability, durability, etc., and secondary pollution is concerned over time. Also known is a method of capturing and stabilizing heavy metal ions by treatment with a chemical agent such as an organic compound. However, such a drug is not only expensive, but also does not have sufficient sustainability for holding heavy metal ions after stabilization treatment. There was a problem that the amount of elution increased.

  Furthermore, as a method for treating waste containing these heavy metals, a method using borax in the presence of water is known, but sufficient elution cannot be controlled over time, and further improvement is necessary. (Patent Documents 1 to 3).

  On the other hand, processing of acetic minerals (inorganic fibers) such as devil minerals, asbestos (various asbestos such as chrysotile and crocidolite), synthetic zonotlite, and glass fibers, which are feared to be called quiet time bombs, are discarded. Further progress has been desired with regard to the disposal process because it is easily scattered during processing and it is difficult to transform a needle-like shape that exhibits toxicity into a shape that does not exhibit toxicity.

  In particular, asbestos waste is a global problem, and if it is not solved quickly, it will leave a root in future generations. However, as currently known for the treatment of splattered asbestos waste, there are plasma melting slag technology at a high temperature of 1500 ° C. or higher, detoxification technology at 700 ° C. using a halogen compound, etc. There was nothing that required energy or was simply diverted from the previous harmful reaction, and nothing superior in cost performance and safety.

  Synthetic zonotlite, which is an alternative to asbestos, also has poor binding properties, and the surface layer fibers are easily detached, and the detached fibers float, and there is a high risk of sucking them, causing health damage in the near future. There is a high possibility that it will be detected. Therefore, an improved technique is now desired for the disposal problem. Further, the glass fiber has a bad influence on the work of waste disposal such as tingling. That is, for example, “GFRP, which is a composite material in which glass fibers are dispersed in unsaturated polyester” frequently used in materials for ships, septic tanks, bathtubs, etc., has no excellent waste disposal method. It was.

  Therefore, even if the waste is chemically toxic, such as particles containing heavy metals, or the form is toxic, such as particles containing acicular particles, Regarding processing, further superior technology has been desired.

  Furthermore, from the viewpoint of resource recycling and from the viewpoint of cost reduction of processing, a technique that can effectively use substances generated by such processing has been desired.

Japanese Patent Application Laid-Open No. 5-087985 JP-A-11-099370 JP 2002-106815 A JP-A-6-090616 JP 2003-019500 A JP 2005-254195 A

  The present invention has been made in view of the above-mentioned background art, and the problem is that particles containing harmful heavy metals, needle-shaped particles, etc., particularly waste particles, are completely, safely, easily and inexpensively detoxified. It is to provide a way to do. It is another object of the present invention to provide a treatment method capable of maintaining the effect of the detoxification treatment over time and preventing secondary pollution. In addition, flame resistance; chemical resistance to acids, alkalis, organic solvents, etc .; antistatic properties due to electrical conductivity; fluidity due to being spherical; weather resistance; water repellency; Is to provide a processing method that can be obtained at a relatively low cost and contributes to resource recycling.

  As a result of intensive studies to solve the above-described problems, the present inventor used at least a treatment liquid containing borax, silicone and water, and the treatment liquid was made into “particles containing metals” under certain conditions. It was found that particles containing metals can be completely detoxified by impregnation and heat melting under the present circumstances, and the present invention has been completed. In addition, the composite particles obtained using the particle treatment method of the present invention are found to be excellent in flame retardancy, conductivity, water repellency, weather resistance, chemical resistance, antistatic properties, cost performance, etc. The present invention has been completed.

  That is, the present invention is a particle treatment characterized by impregnating at least a treatment liquid containing borax, silicone and water into particles containing metals and then heating and melting at a furnace temperature of 600 ° C. or higher. A method is provided.

  Further, in the present invention, before impregnating the particles containing the metal with the treatment liquid, the particles containing the metal are impregnated with the pretreatment liquid containing borax and water at 60 ° C. or higher. The particle processing method is provided.

  In addition, the present invention provides a composite particle obtained by using the above particle processing method and containing metals, boron, carbon and silicon.

  According to the present invention, “particles containing metals”, for example, particles containing waste particles, heavy metal particles and needle-like particles can be completely detoxified until they become stable over time, Safe, simple and inexpensive. In addition, composite particles excellent in flame retardancy; conductivity; chemical resistance to acids, alkalis, organic solvents, etc .; antistatic properties; fluidity; weather resistance; water repellency; When the particles are waste particles, it can also contribute to resource recycling.

In Example 10, composite particles obtained by using crocidolite instead of dispersible asbestos, which are acicular particles, were (a) refractive index n _D ^{25 ° C.} = 1.550, (b) refractive index n _D ^{25 ° C.} = 1.680, (c) Refractive index n _D ^{25 ° C.} = 1.700.

  Hereinafter, the present invention will be described. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented.

  In the present invention, a treatment liquid containing at least borax, silicone and water (hereinafter simply abbreviated as “treatment liquid”) may be abbreviated as particles containing metals (hereinafter simply abbreviated as “particles”). ) And then melted by heating. Further, preferably, before the treatment, particles containing the metals are impregnated with a pretreatment solution containing borax and water (hereinafter simply referred to as “pretreatment solution”). To do. Hereinafter, the treatment of impregnating the particles with the treatment liquid may be simply abbreviated as “treatment”, and the treatment of impregnating the particles with the pretreatment liquid may be simply abbreviated as “pretreatment”.

  The treatment liquid and the pretreatment liquid may be prepared separately, but after treatment with the pretreatment liquid, a treatment liquid may be prepared by additionally blending silicone into the pretreatment liquid. In the present invention, “impregnating a particle with a pretreatment liquid or a treatment liquid” means that the pretreatment liquid or the treatment liquid is substantially added to secondary particles (also referred to as “particles”) that are particles or an aggregate of particles. It means to be in a state where it has soaked until it reaches a certain invariable state. The adhesion of the pretreatment liquid or the treatment liquid to the surface of the particles and the intrusion into the inside of the particles are both included in “impregnating the particles”. It is also included in “impregnating particles” to penetrate into the interior of secondary particles or particle clusters and adhere to the surface of substantial primary particles.

<Borax>
Borax is an essential component in both the treatment liquid and the pretreatment liquid. The “borax” in the present invention is a hydrous borate mineral of sodium, specifically [Na ₂ B ₄ O ₇ · 10H ₂ O] or [Na ₂ B ₄ O ₅ (OH) ₄ · 8H. ₂ O], or a substance represented by [Na ₂ B ₄ O ₇ · 5H ₂ O] or [Na ₂ B ₄ O ₅ (OH) ₄ · 3H ₂ O], and hydrated sodium tetraborate It is. When heated to 350-400 ° C., borax becomes anhydrous, and when further heated, it melts at around 878 ° C. and becomes a colorless and transparent glass. The borax melt has the property of dissolving many metal oxides and forms a borate with the metal to stabilize the metals. In particular, harmful heavy metals and borates can be generated to stabilize and detoxify heavy metals.

  Also, the borax melt surrounds heavy metal-containing particles, acicular particle-containing particles, waste particles, waste particles containing heavy metals or acicular particles, etc., and stable and harmless composite particles over time. Can be generated. In addition, the obtained composite particles are flame retardant; antistatic property due to conductivity; chemical resistance against acid, alkali, organic solvent, etc .; fluidity due to spherical shape; weather resistance; water repellency; Excellent cost performance.

  Furthermore, when borax is used, even when heating and melting is performed in an oxygen-containing gas atmosphere, when the components fused and vitrified in a low temperature region block oxygen and organic substances coexist, carbonization becomes easy. Further, the heat resistance is improved, and composite particles having extremely excellent performance can be provided as a result of the particle processing method of the present invention.

The content of the borax in the treatment liquid and the pretreatment liquid can be appropriately adjusted depending on the kind and particle diameter of the particles to be treated and the treatment temperature, but preferably 5 parts by mass with respect to 100 parts by mass of water. Above, more preferably 15 parts by mass or more, particularly preferably 20 parts by mass or more. Further, it is preferably 100 parts by mass or less, more preferably 60 parts by mass or less, and particularly preferably 40 parts by mass or less. The borax used may differ in the degree of hydration, but in the present invention, the “mass part of borax” in the case of defining the concentration of the borax aqueous solution, etc. means “Na ₂ B ₄ O _7. 10H ₂ O] or a mass part when the degree of hydration is converted to [Na ₂ B ₄ O ₇ · 10H ₂ O].

  If there is too much borax, workability is not good, even if you try to dissolve it by heating, it will not dissolve completely in relation to the saturation concentration, borax will precipitate during treatment with the treatment liquid or pretreatment with the pretreatment liquid In particular, a treatment liquid containing silicone is preferably treated at a relatively low temperature. However, in this case, it tends to precipitate, and a part not dissolved in water is wasted and is disadvantageous in cost. is there. On the other hand, if the amount is too small, the particles containing the metals may not be sufficiently harmless, and the weather resistance, flame retardancy, and the like may be lacking.

  The treatment liquid and the pretreatment liquid in the present invention contain borax in a dissolved state in water in that the borax can penetrate or coat the particles containing metals more efficiently. preferable. The present invention is characterized by impregnating borax into particles containing metals in a state of being dissolved in water, rather than mixing borax with particles containing metals in a solid state and heating and melting. . Furthermore, during the treatment with the treatment liquid or the pretreatment with the pretreatment liquid, the borax is preferably dissolved in water at a high concentration at the treatment temperature, and may be contained in a saturated or supersaturated state. Particularly preferred. Therefore, the treatment liquid and / or the pretreatment liquid is prepared by heating at least borax and water to the boiling point of the finally obtained aqueous solution or close to the boiling point to completely dissolve the borax in water. It is preferable to prepare. During the treatment of the particles or during the pretreatment, the treatment liquid and the pretreatment liquid are preferably used by appropriately cooling from near the boiling point to an appropriate temperature. In that case, it is preferable to use borax to such an extent that borax does not precipitate.

<Silicone>
The treatment liquid in the present invention must contain silicone. The “silicone” in the present invention is a polyorganosiloxane having a siloxane bond as a skeleton. When silicone is contained in the treatment liquid of the present invention, elution of (heavy) metals from (heavy) metals particles is suitably prevented, and more stable and harmless composite particles can be generated for a long time. Further, by containing silicone, composite particles excellent in chemical resistance, weather resistance, water repellency, and low toxicity can be produced. Organic groups such as carbon-containing organic groups in the silicone remain at least partially after the borax and the particles are heated and melted, and give the above performance to the composite particles obtained after the heating and melting.

  Examples of silicone include those in which an alkyl group such as a methyl group or an aryl group such as a phenyl group is substituted on the silicon atom, and modified silicone oils are also included. As the silicone, those having various properties such as oil, rubber, resin and the like can be used, but silicone oil (oil-like one) is preferable from the viewpoint of being easily dispersed as an emulsion in water.

  Specifically, for example, straight silicone oils such as methyl hydrogen silicone oil, dimethyl silicone oil, and methylphenyl silicone oil; modified silicone oils such as alkyl-modified silicone oil, amino-modified silicone oil, fatty acid-modified silicone oil, and epoxy-modified silicone oil Silicone rubber; varnish, molding compound, silicone resin such as junction coating resin, and the like. You may use these 1 type or in mixture of 2 or more types. Among these, straight silicone oils such as dimethyl silicone oil and methylphenyl silicone oil are versatile, have many types, and easily give long-term stability and chemical resistance to the resulting composite particles. Is particularly preferable.

  The silicone may be added to the treatment liquid by adding a “silicone emulsion” in which silicone is dispersed in water as an o / w emulsion in advance, and the silicone alone may be prepared in water or borax. A treatment liquid may be prepared by adding to a borax aqueous solution in which is dissolved.

  When preparing a treatment liquid by adding a silicone emulsion, it is preferable to add borax after heating and dissolving it in water. In that case, it is preferable to add a silicone emulsion at 10-80 degreeC, It is more preferable to add at 12-50 degreeC, It is especially preferable to add at 15-30 degreeC. If the temperature is too low, borax once dissolved may precipitate, and if the temperature is too high, the emulsion state of the silicone emulsion may not be maintained or the dispersibility of the silicone may deteriorate. It is particularly preferable to prepare a treatment liquid by adding a silicone emulsion to the pretreatment liquid after the pretreatment. At that time, it is preferable to add the silicone emulsion after cooling the pretreatment liquid to an appropriate temperature.

  When preparing a treatment liquid by adding silicone alone to water or a borax aqueous solution, it is preferable to prepare a treatment liquid by adding silicone alone to a borax aqueous solution. It is particularly preferable to prepare the treatment liquid by adding it to the pretreatment liquid. At this time, it is preferable to add the silicone alone after cooling the pretreatment liquid to an appropriate temperature. Usually, silicone is dispersed in water. When dispersing silicone alone in water, it is preferable to use a surfactant, polyaluminum chloride (PAC), which will be described later, or the like for improving dispersibility and emulsification. As will be described later, polyaluminum chloride (PAC) not only exhibits the effects of the present invention more remarkably, but also functions as a dispersibility improver for silicone in water.

  The silicone content is preferably 2 to 50 parts by mass, more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the treatment liquid in the present invention as a silicone simple substance when using a silicone emulsion. It is particularly preferably 10 to 30 parts by mass. If the amount of silicone is too small, the water resistance and chemical resistance may be inferior, and the silicone-containing effect may not be obtained. On the other hand, if the amount is too large, the silicone is sufficiently dispersed in the treatment liquid of the present invention. Or may be disadvantageous in terms of cost.

<Water>
In the present invention, the treatment liquid and the pretreatment liquid contain water as an essential component. Water is used to dissolve the above-described borax, is contained in a silicone emulsion, or is added separately. If there is too much water, the metal-containing particles are not sufficiently impregnated with components such as borax in the treatment liquid and the pretreatment liquid, it takes time and energy to evaporate water, and it takes time to heat and melt. Workability may be reduced. In the present invention, it is necessary to impregnate particles (with a borax aqueous solution) of dissolved borax, but if the amount of water is too small, the borax may not be completely dissolved even when heated.

<Water-soluble organic matter>
In the particle treatment method of the present invention, it is preferable that the treatment liquid and / or the pretreatment liquid further contains a water-soluble organic substance. By containing a water-soluble organic substance, the melting point of borax can be lowered during the heat melting in the particle processing method of the present invention. Further, if the carbonaceous material remains in the product obtained by heating and melting, composite particles excellent in antistatic property and heat resistance due to conductivity can be provided, but it becomes a carbon source of the carbonaceous material. . In addition, composite particles having a small specific gravity can be provided. “Carbonaceous material” refers to a substance consisting essentially of carbon atoms, crystalline materials such as graphite, and amorphous materials in which no peak is observed by powder X-ray diffraction, and intermediate materials between them. Is also included.

  The “water-soluble organic substance” in the present invention does not need to be readily soluble in water, and may be substantially dissolved in water even at a slight temperature at the time of treatment or pretreatment. Accordingly, the treatment liquid and pretreatment liquid in the present invention are not particularly limited as long as the water-soluble organic substance is partially dispersed together with the solution, and a solid or liquid organic substance can be used at room temperature. However, in order to increase the amount of the water-soluble organic substance impregnated in the particles, it is preferable that the solubility in water is large, and it is preferable that the particles are completely dissolved in the treatment liquid and the pretreatment liquid. Moreover, even if the substance is hardly soluble in pure water, such a water-soluble organic substance is also preferable because it may be easily soluble in the treatment liquid and the pretreatment liquid in the present invention.

  Among the “water-soluble organic substances” in the present invention, “organic substances that are liquid at room temperature” are not particularly limited, but monohydric alcohols such as methanol, ethanol, and propanol; ethylene glycol, propylene glycol, glycerin, polyethylene glycol, polypropylene glycol Polyhydric alcohols such as acetone, tetrahydrofuran, methyl isobutyl ketone, dibutyl ketone, cyclohexanone, etc .; esters such as ethyl acetate, butyl acetate, and ethyl butyrate; long-chain fatty acid esters such as lauric acid ester and linoleic acid ester Vegetable oil; animal oil; chlorine-containing hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethylene; carbon containing bromine or iodine Motorui: toluene, xylene and the like aromatic hydrocarbons; petroleum reserves or their fractions such as coal tar and the like. These are used alone or in combination of two or more. If the furnace is heated and melted at a furnace temperature of 600 ° C. or higher by the particle processing method of the present invention, even if the furnace temperature or the furnace set temperature is 800 ° C. or lower, the temperature of the melting object itself is 1000 ° C. or higher. Since it often reaches 1050 ° C. or higher, harmful chlorine-containing organic substances such as dioxins are hardly formed as by-products even if they contain chlorine.

  Among the “water-soluble organic substances” in the present invention, “solid organic substances at room temperature” are not particularly limited, but monosaccharides such as glucose (fructose) and fructose (fructose); disaccharides such as sucrose (sugar); Examples thereof include polysaccharides such as starch; glycosides; sugar alcohols such as sorbitol and mannitol; water-soluble polymers such as polyvinyl alcohol and polyvinylpyrrolidone. These are used alone or in combination of two or more.

  Among them, glucose, fructose, sucrose (sugar), starch and other sugars or sugar derivatives have a high boiling point, are easy to handle, have high solubility in water, are highly safe, are inexpensive, and are melted by heating. It is preferable in terms of providing better light composite particles. The form of the saccharide or its derivative is not particularly limited, but sugars such as sucrose, tri-warm sugar; starch derived from plants such as potato and corn or starch-based paste; rice flour, glutinous rice flour, wheat flour, corn flour, etc. Flour; potato starch and the like are particularly preferred from the above points.

  The water-soluble organic substance is preferably 1 part by mass to 100 parts by mass, more preferably 2 parts by mass to 80 parts by mass, and particularly preferably 5 parts by mass with respect to 100 parts by mass of the treatment liquid or pretreatment liquid in the present invention. It is -60 mass parts, More preferably, it is 20 mass parts-35 mass parts. When the amount of the water-soluble organic substance is small, the temperature of the object to be melted containing particles and borax is less likely to be higher than the set temperature in the furnace when heated and melted, resulting in an increase in cost or a harmful chlorine-containing organic substance such as dioxin. May be generated. Further, only a small amount of carbonaceous matter remains in the composite particles obtained after the treatment, and the antistatic property, heat resistance, etc. of the composite particles, which are the effects of the present invention, are not sufficient, and the above-mentioned effect of containing the water-soluble organic matter is obtained. In some cases, if the amount is too large, the physical properties will not be improved any more, which may be useless.

  The method for blending the water-soluble organic substance is not particularly limited. After the borax is dissolved in water by heating, the water-soluble organic substance may be added and dissolved, or the borax and the water-soluble organic substance are dissolved in water by heating at the same time. May be. Moreover, it is particularly preferable from the viewpoint of workability and the like to prepare a treatment liquid by treating particles with a pretreatment liquid containing borax and water and then adding a water-soluble organic substance and silicone to the pretreatment liquid.

<Polyaluminum chloride>
The treatment liquid in the present invention preferably further contains polyaluminum chloride. “Polyaluminum chloride” is a substance represented by [Al ₂ (OH) _n Cl _6-n ] _m (1 <n <5), which is mainly composed of a polynuclear complex of aluminum bridged by OH, Or the aqueous solution. It is preferable to dissolve aluminum hydroxide in hydrochloric acid, add a solubilizing agent under pressure or if necessary, and add a sulfuric acid group as a polymerization accelerator to react. The dissolution aid and the polymerization accelerator are not particularly limited as long as they do not impair the effects of the present invention. In the above formula, m is preferably 10 or less. In addition, since “solid polyaluminum chloride” or “aqueous solution of polyaluminum chloride” is usually referred to as “PAC”, in the present invention, they are collectively referred to as “PAC” hereinafter. In the present invention, what is generally called “polyaluminum chloride” or “PAC” and commercially available for water purification or wastewater treatment can also be suitably used. As the PAC, either an aqueous solution or a solid solution can be used. In the present invention, the aluminum content in the PAC used is not particularly limited, but is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, and particularly 8 to 15% by mass in terms of aluminum oxide. Among them, those having 10.0 to 11.0% by mass (for example, those described in “JIS K 1475”) and the like are preferably used.

  When PAC is contained, the dispersibility of silicone in the treatment liquid in water is improved, and physical properties such as stability of the composite particles obtained after heating and melting are improved, and the effect of the present invention is further improved. It will be obtained. The content of PAC in the treatment liquid is not particularly limited, but aluminum is preferably 10 mass% PAC (aqueous solution) in terms of aluminum oxide, preferably 15 mass% or less in the treatment liquid, and 5 mass% to 10 mass%. More preferably, 7% by mass to 8% by mass is particularly preferable.

<Other substances>
The treatment liquid in the present invention may further contain other substances other than those described above. Examples of such “other substances” include phosphoric acid (hydrogen) salts such as diammonium hydrogen phosphate and sodium hydrogen phosphate; (bi) carbonates such as ammonium bicarbonate, sodium bicarbonate and sodium carbonate. These can be heated together with borax to further improve the flame retardancy of the composite particles, and are also effective as a pH value adjusting agent.

  “Other substances” also include surfactants. Surfactants are mainly used to facilitate the dispersion of silicone in water. Specific examples include nonionic surfactants such as food-added sorbitan fatty acid and coconut oil fatty acid alkanolamide, and amphoteric surfactants such as coconut oil fatty acid.

<Particles containing metals>
The particle treatment method of the present invention is a method in which the above-described treatment liquid is impregnated with “particles containing metals” and then heated and melted at a furnace temperature of 600 ° C. or higher. Here, the “particles containing metal” means a particle containing a metal as an element, and may contain other components as long as the particle contains a metal. There are no particular limitations on the size, particle shape, etc. of the particles. Here, “metals” includes heavy metals, light metals, and semimetals. “Containing metal” means not only containing as a metal, that is, as a metal element alone, but also containing all organic and inorganic metal compounds having a metal element as a constituent element.

  The metal is not particularly limited, but specifically, for example, iron, lead, copper, chromium, cadmium, mercury, zinc, arsenic, manganese, cobalt, nickel, molybdenum, tungsten, tin, bismuth, uranium, Heavy metals such as strontium; light metals such as aluminum, magnesium, beryllium, titanium, alkali metals, and alkaline earth metals; and semimetals such as germanium, arsenic, and silicon. Gold; platinum group metals such as platinum and palladium; silver and the like are also included in the above-mentioned metals, but it is preferable that a separate treatment such as recovery is performed as a noble metal regardless of the present invention.

  The volume average particle size of the “particles containing metals” of the present invention is the workability, the point that metals can be efficiently fixed, and the volume average particle size desired as composite particles which are valuable materials obtained after heating and melting. Is preferably 1 μm to 3 mm, more preferably 10 μm to 1 mm, and particularly preferably 30 μm to 100 μm. In order to obtain the preferred particle size, before impregnation with the treatment liquid or pretreatment liquid in the present invention, mechanical pulverization may be performed according to a conventional method, if necessary.

  The “particles containing metals” are not particularly limited as long as they are described above. However, the waste particles can be detoxified for wastes containing metals, and can be recycled. Is preferable. Here, the waste particles are obtained by pulverizing waste particles discharged from a home, factory, incinerator, or the like, or discharged waste. In particular, wastes such as crushed slag, steel slag, zinc slag, glaze sludge, dyed sludge, foundry sand, pigments and printing ink contain a large amount of metals, so the particle treatment method of the present invention is particularly preferably applied. it can.

  It is preferable that the waste is pulverized and used as the waste particles in the particle treatment method of the present invention because the detoxification treatment can be efficiently performed and the obtained composite particles can be easily reused as valuable materials.

  The waste particles are preferably heavy metal-containing particles or acicular particle-containing particles. In many cases, they are chemically or formally harmful, and since it is strongly desired to treat them to be stable over time, it is particularly preferable because the effects of the present invention described above are easily obtained.

  Examples of the heavy metal-containing particles among the waste particles include, for example, iron slag, smelting slag, slag slag, mineral slag, dyed sludge, glaze sludge, foundry sand, pigment sludge, various printing ink wastes, medical waste, Particles such as contaminated soil, or those obtained by pulverizing them to form particles.

  Examples of the acicular particles in the “acicular particles-containing particles” among the particles containing metals include serpentine stones such as chrysotile (warm asbestos, white asbestos), crocidolite (aoishi cotton), amosite (tea asbestos) , Anthophyllite, tremolite, actinolite and other asbestos-based asbestos; wollastonite, zonotolite and other calcium silicates; glass wool; rock wool; carbon fiber; alumina fiber; synthetic zonotlite; Among these, asbestos is particularly preferable because it is particularly toxic and can exhibit the effect of the particle processing method of the present invention. Since asbestos contains magnesium and silicon as metals, waste particles containing asbestos are conceptually included in particles containing metals.

  Examples of the acicular particle-containing particles among the waste particles include the acicular particles, the composite particles containing the acicular particles and a binder resin or mortar, or particles obtained by pulverizing them. . Specifically, for example, “composites in which glass fibers are dispersed in a curable resin” (including what is called “GFRP”), which is widely used for materials such as ships, septic tanks, and bathtubs; Examples include “composites in which asbestos is dispersed in mortar and the like” used for materials such as asbestos slate and high-temperature pipes; demolished building materials such as gypsum board and sound absorption tex.

  Examples of the binder resin constituting the waste together with the acicular particles include thermosetting resins such as unsaturated polyester resins, phenol resins, and epoxy resins; thermoplastic resins such as acrylic resins, polyester resins, and polyvinyl resins. Since these organic resins serve as a carbon source, carbonaceous materials remain in those obtained by heating and melting, and therefore it may be preferable that they are contained in waste.

  The volume average particle size of the waste particles is the same as the volume average particle size of the above-mentioned “particles containing metals”. The reason for the preferred range is also the same. In order to obtain the preferred particle size, before impregnation with the treatment liquid or pretreatment liquid in the present invention, mechanical pulverization may be performed according to a conventional method, if necessary.

  If the particle | grain processing method using the borax and silicone of this invention is used, the melt of borax surrounds heavy metals and needle-shaped particles, and it can carry out the detoxification process safely with time.

<Organic chlorine compounds>
The “particles containing metals” in the present invention may further contain an organic chlorine compound. The organic chlorine compound is not particularly limited as long as it is an organic compound containing a chlorine atom. When waste containing an organic chlorine compound is burned at a low temperature, dioxins and dioxin-like compounds (hereinafter abbreviated as “dioxins”) are produced as by-products. The dioxin-like compound is a substance showing toxicity similar to that of dioxin, such as polychlorinated dibenzopararadixin, polychlorinated dibenzofuran, coplanar polychlorinated biphenyl.

  Dioxins are generated when the organic chlorine compound is incompletely combusted, and the amount generated is almost independent of the concentration when the chlorine concentration contained in the burned organic chlorine compound is about 0.1 to 50% by mass, Generally, it is determined by combustion conditions. By using the particle treatment method using borax and silicone according to the present invention, almost no harmful substances such as dioxins are produced, and even if produced, the borax melt surrounds it and can be safely rendered harmless over time. .

  In the present invention, the “particles containing metals” are preferably 1 part by mass to 100 parts by mass, more preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the treatment liquid in the present invention. Preferably they are 10 mass parts-30 mass parts. If there are too few “metal-containing particles”, the cost performance may be poor. If too much, the “metal-containing particles” may not be detoxified or composite particles may be obtained. Even if it is not obtained, flame retardancy may be inferior.

<Pretreatment liquid and treatment liquid>
In the particle treatment method of the present invention, after impregnating the above-mentioned treatment liquid containing at least borax, silicone, and water into “particles containing metals”, the mixture is heated and melted at a furnace temperature of 600 ° C. or higher. It is characterized by. Since the treatment liquid in the present invention has low water solubility of borax, it is preferable to dissolve borax in hot water in advance. More preferably, the borax is heated to the boiling point of the obtained borax aqueous solution to completely dissolve the borax in water. Thereafter, it is preferable to add silicone after cooling to an appropriate temperature. At that time, a water-soluble organic substance may be dissolved therein.

  Before impregnating the particles with the treatment liquid, it is preferable to impregnate the particles with a pretreatment liquid containing borax and water. After impregnating the pretreatment liquid containing borax and water into the “metal-containing particles”, it is cooled to an appropriate temperature as it is, and silicone is further added to the particles so that the particles remain contained. It is preferable from the viewpoint of workability to prepare the treatment liquid.

  In the treatment liquid in the present invention, silicone is preferably added to the above-described pretreatment liquid at 10 to 80 ° C, more preferably at 12 to 50 ° C, and particularly preferably at 15 to 30 ° C. . If the temperature at this time is too high, the dispersion of silicone in the treatment liquid may deteriorate.

  When the treatment liquid in the present invention contains a water-soluble organic substance, there are no particular limitations on the stage, order, temperature, etc. of adding the water-soluble organic substance, and silicone is added to the pretreatment liquid that already contains the water-soluble organic substance. Even if the liquid is prepared, a water-soluble organic substance may be added to the pretreatment liquid that does not contain a water-soluble organic substance, if necessary, to prepare a processing liquid.

<Particle treatment method (impregnation)>
The particle treatment method of the present invention is characterized in that the above-described treatment liquid of the present invention is impregnated in “particles containing metals” and then heated and melted. The temperature at which the treatment liquid is impregnated (treatment temperature) is not particularly limited as long as the particles can be sufficiently impregnated with the components, but is preferably 30 to 80 ° C, more preferably 40 to 70 ° C, and more preferably 50 to 60 ° C. Is particularly preferred. If the temperature is too low, dissolved borax may precipitate or impregnation of the treatment liquid into “particles containing metals” may be insufficient. If the temperature is too high, silicone dispersion may occur. The state may not be maintained or the effects of the present invention may not be sufficiently obtained. Therefore, the temperature of the treatment with the treatment liquid containing silicone is preferably lower than the temperature of the pretreatment with the pretreatment liquid not containing silicone.

  The time for impregnating the particles is not particularly limited as long as the particles are sufficiently impregnated, but is preferably 10 minutes or more, more preferably 30 minutes to 24 hours, and particularly preferably 1 hour to 3 hours. While the particles are impregnated, it is preferable to maintain the treatment liquid at the above temperature so that the components are sufficiently impregnated with the particles.

  In addition, in order to sufficiently infiltrate or coat borax into the “particles containing metals”, the “particles containing metals” are impregnated in advance with the pretreatment liquid before impregnation with the treatment liquid. Is preferred. The pretreatment liquid contains at least borax and water. If silicone is contained in the pretreatment liquid, when the pretreatment liquid is raised to the preferred pretreatment temperature described below, the silicone emulsification is destroyed or the dispersibility of the silicone is deteriorated. As a result, the pretreatment liquid May be separated into layers.

  The temperature of the pretreatment is preferably 60 ° C. or higher, more preferably 70 ° C. to the boiling point of the pretreatment liquid, and particularly preferably 80 ° C. to 100 ° C. in terms of sufficiently impregnating borax. If the temperature is too high, the pretreatment liquid may be excessively boiled and unstable, while if the temperature of the pretreatment liquid is too low, the borax does not sufficiently impregnate the particles and is dissolved in water. In some cases, borax deposits and the permeability, that is, insufficient loading in the particles is insufficient.

  The time for impregnating the particles is not particularly limited as long as the particles are sufficiently impregnated, but is preferably 2 minutes or more, more preferably 5 minutes to 3 hours, and particularly preferably 10 minutes to 2 hours. While the particles are impregnated, it is preferable to maintain the treatment liquid at the above temperature so that the components are sufficiently impregnated with the particles.

  After the pretreatment, it is preferable to add silicone after the temperature of the pretreatment liquid is lowered and perform the treatment with the treatment liquid described above.

<Particle processing method (heat melting)>
Next, the particles impregnated with the treatment liquid are heated and melted. The water contained in the treatment liquid may be distilled off by heating and melting, but it is also preferable to evaporate and distill water according to a conventional method prior to heating and melting. In addition, when melting by heating, it is preferable to heat and melt the particles and the treatment liquid as they are without filtering off the treatment liquid impregnated in the “metal-containing particles”.

  Examples of the heating and melting method include a method of standing in a heating furnace and heating and melting, a method of directly contacting a flame, a method of supplying to a continuous firing furnace, a method using a slider dropping method, and the like. The method of continuously dropping into the furnace using a tower type production furnace is preferable in that composite particles having a uniform particle diameter can be obtained continuously in a short time. In addition, a method in which a flame is directly contacted with a cup burner or the like is also preferable in terms of good thermal efficiency. There is no particular limitation on the combustion gas in the method of directly contacting the flame, but hydrogen, methane, ethane, propane, butane, carbon monoxide, city gas and the like are preferable.

  The furnace temperature or the set temperature in the furnace for heating and melting must be 600 ° C. or higher. Preferably it is 630 degreeC-1300 degreeC, More preferably, it is 660 degreeC-1000 degreeC, Most preferably, it is 700 degreeC-800 degreeC. If the furnace temperature or the furnace set temperature is too low, the borax does not melt sufficiently, and particles such as heavy metal-containing particles and acicular particle-containing particles may not be sufficiently contained by the borax or carbonaceous material. On the other hand, if it is too high, the cost may increase.

  When the temperature of the target object (borax, particles, preferably water-soluble organic substance, PAC is integrated) in heating and melting is the above furnace temperature or set temperature in the furnace, it is usually 750 ° C. or higher in a steady state. However, it is particularly preferable that the temperature be in the range of 800 ° C to 1100 ° C. When organic substances such as water-soluble organic substances and resins contained in the waste coexist, the temperature of the object tends to be higher than the furnace temperature or the set temperature in the furnace, and the cost during heating can be reduced. Since the object becomes high temperature, the generation of harmful chlorine-containing organic substances such as dioxins and dioxin-like compounds can be suppressed, and the complete combustion effect of the gas generated during heating and melting can be obtained. In the present invention, it is preferable to adjust the composition of the treatment liquid and the pretreatment liquid so that the temperature of the object to be heated and melted becomes higher than the furnace temperature.

  The heating and melting atmosphere is not particularly limited, and may be any of vacuum; an inert gas such as nitrogen or argon; an active gas such as air or oxygen. In the present invention, even when heating and melting is performed in the air, when the water-soluble organic compound is contained in the treatment liquid or the pretreatment liquid, all the organic compound burns and all the carbon in the organic compound is carbon dioxide. And remain in the composite particle as a carbonaceous material. Since the carbonaceous material remains in the product obtained by heating and melting, it is preferable to perform heating and melting in an oxygen-containing gas atmosphere because the temperature can be increased. In addition, it is particularly preferable that the oxygen-containing gas is air, which can be easily heated and melted, resulting in cost reduction.

  The time for heating and melting is not particularly limited, but is preferably 3 minutes to 40 minutes, and particularly preferably 5 minutes to 20 minutes in the method of standing in a heating furnace and heating and melting. Moreover, in the method of flame-contacting directly in a furnace, 3 minutes-20 minutes are preferable, 4 minutes-15 minutes are more preferable, and 5 minutes-10 minutes are especially preferable.

<Composite particle>
What is obtained by heating and melting is preferably 100 μm to 2 mm, particularly preferably 300 μm to 1 mm, but is pulverized or pulverized as necessary to form particulate or powdery “composite particles”. It is preferable in terms of easy handling and easy reuse as a valuable resource. Crushing or crushing is performed according to a conventional method. The volume average particle size of the composite particles obtained by crushing or pulverization is not particularly limited, but is preferably 10 μm to 1 mm, more preferably 15 μm to 300 μm, and particularly preferably 20 μm to 100 μm.

  The “composite particles” of the present invention are obtained by using the above-described particle processing method, and are characterized by containing at least metals, boron, carbon and silicon. The metals, boron, carbon and silicon are derived from the above-mentioned “treatment liquid in the present invention”, and the specific composition and specific structure thereof are not particularly limited. That is, when water-soluble organic substances are contained in the treatment liquid or organic substances are contained in the waste, even if the carbon in the composite particles has a graphite (graphite) structure by carbonization, It may be an intermediate carbon precursor or amorphous carbon, and it is preferable that a carbonaceous material remains.

  The composite particles of the present invention are particles excellent in flame retardancy; conductivity; chemical resistance to acids, alkalis, organic solvents, etc .; antistatic properties; fluidity; weather resistance; water repellency; In particular, metals, silicon, and carbon contained in the composite particles improve heat resistance, and boron improves flame retardancy. Further, when the particles are heavy metal-containing particles, it is preferable because the heavy metals can be stably immobilized harmlessly and the heat resistance and the like are improved.

<Action and principle>
In the present invention, when the treatment liquid is used, the "action and principle of being able to completely detoxify" particles containing metals "such as waste particles, heavy metal-containing particles and needle-like particle-containing particles. Although it is not clear, the following can be considered. However, the present invention is not limited to the scope of the following actions and principles. By impregnating particles containing metals with a solution in which borax is dissolved in hot water, that is, by infiltrating or coating borax dissolved in hot water, the particles are easily melted red hot when heated and melted. Vitrified. It is thought that by impregnating the liquid, it can be made completely harmless than simply mixing in a solid state and heating and melting. In addition, by containing silicone, the metals coated in this glass state do not elute under normal circumstances, and the effect of the detoxification treatment can be maintained over time to prevent secondary pollution. it can. After heating and melting, the chemical structure of silicone may change, but the above effect is exhibited. Further, due to the coexistence of borax and silicone, the organic matter becomes a carbonaceous matter and remains in the composite particles.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples unless it exceeds the gist.

Example 1
<Processing liquid A>
50 masses of sucrose, which is a water-soluble organic substance, in 100 parts by mass of “borax and water” which becomes an 18 mass% borax (Na ₂ B ₄ O ₇ · 10H ₂ O) aqueous solution when completely dissolved 6 parts by mass of a% aqueous solution was added and stirred while heating at 100 ° C. until borax was dissolved. This aqueous solution (this aqueous solution is referred to as “pretreatment liquid a”) was cooled to 100 ° C. to 30 ° C., and 10 parts by mass of a dimethyl silicone silicone emulsion (manufactured by Toray Industries, Inc., 1980) was added to prepare a treatment liquid A.

  To 90 parts by mass of the treatment liquid A prepared above, 10 parts by mass of iron slag pulverized to a volume average particle diameter of 1 mm was added. The heavy metal-containing particles were heated at 60 ° C. for 1 hour so that the treatment liquid A was impregnated. Next, in an oxygen-containing gas atmosphere (in the air), the mixture was heated and melted at a furnace internal temperature of 750 ° C. and a furnace temperature of 750 ° C. for 10 minutes. Two minutes after the start of heating, the surface of the sample had reached 1050 ° C. (temperature difference from the furnace temperature 300 ° C.). Uniform black glass particulate composite particles A were obtained. The obtained composite particles A1 were almost spherical, and had a particle size of 300 μm to 500 μm, and contained heavy metals, boron, carbon, and silicon.

Comparative Example 1
In Example 1, iron slag was added to the treatment liquid A and allowed to stand at 20 ° C. for 1 hour without heating. However, borax was recrystallized and precipitated on the way, and contained “borax, silicone and water. The “treatment liquid” was not impregnated in the “particles containing metals”. Thereafter, the water was evaporated as it was, and heating and melting were carried out under the same conditions as in Example 1. However, since borax did not spread throughout the slag, vitreous particulate composite particles were not obtained, and metals It was not possible to detoxify the particles containing.

Comparative Example 2
In Example 1, instead of heating and melting at a furnace temperature of 750 ° C. for 10 minutes, heating was performed at a furnace temperature of 400 ° C. for 10 minutes, but borax was not vitrified and composite particles were not obtained. It did not lead to detoxification of particles containing sucrose. Moreover, although heating temperature was raised and it heated for 10 minutes with the furnace internal temperature of 450 degreeC, the composite particle was not obtained, and it did not lead to the harmless process of the particle | grains containing metals.

Comparative Example 3
In Example 1, the pretreatment liquid a before adding the silicone emulsion was used in place of the treatment liquid A of Example 1, and the steelmaking slag was impregnated under the same conditions as in Example 1 to perform heat melting. Although composite particles (referred to as “composite particles P”) were obtained, the composite particles P were inferior in stability, detoxification, and low toxicity because they could not control elution of sufficient heavy metals. Moreover, water repellency, chemical resistance, etc. were bad, and it could not be completely encapsulated, and the particles containing metals were not detoxified.

Example 2
<Pretreatment liquid a, treatment liquid A>
To 90 parts by mass of the pretreatment liquid a prepared in Example 1, 10 parts by mass of the same crushed iron slag as used in Example 1 was added, and the pretreatment liquid a was “pulverized at 90 ° C. for 10 minutes. Impregnated steelmaking slag particles ”(pretreatment was performed).

  Next, this liquid (pretreatment liquid a in which iron slag is dispersed) is cooled to 90 ° C. to 30 ° C. or less, and the same silicone emulsion as in Example 1 is added to this liquid. In addition to having the same composition as A, the same treatment as in Example 1 was performed, and heating and melting were performed in the same manner. Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1100 ° C. The obtained composite particle A2 was substantially spherical, and its particle size was 0.3 mm to 0.4 mm, and contained heavy metals, boron, carbon, and silicon.

Comparative Example 4
In Example 2, only the pretreatment with the pretreatment liquid a was performed, and the treatment with the treatment liquid A containing silicone was not performed, but the heat melting was performed in the same manner as in Example 2. That is, in Comparative Example 3, instead of impregnation at 60 ° C. for 1 hour, after impregnation at 90 ° C. for 10 minutes, heating and melting were similarly performed.

  Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1100 ° C. The obtained composite particles Q had a particle size of 0.5 mm to 1.5 mm, and contained heavy metals, boron, and carbon. Although this composite particle Q was able to control elution of heavy metals to some extent, it was poor in water repellency, chemical resistance, etc., and did not lead to complete detoxification of particles containing metals.

Example 3
<Processing liquid B>
In Example 1, a treatment liquid was prepared in the same manner as in Example 1 except that a 50% by mass aqueous solution of sucrose (sucrose), which is a water-soluble organic substance, was not added (referred to as Treatment liquid B). Then, the mixture was heated and melted. Two minutes after the start of heating, the surface of the sample had reached 1050 ° C. (temperature difference from the furnace temperature 300 ° C.). Uniform black glass particulate composite particles B1 were obtained. The obtained composite particle B1 was substantially spherical, its particle size was 0.5 mm to 0.8 mm, and contained heavy metals, boron, and silicon.

Example 4
<Pretreatment liquid b, treatment liquid B>
In Example 1, a pretreatment liquid was prepared in the same manner as in Example 1 except that a 50% by mass aqueous solution of sucrose (sucrose), which is a water-soluble organic substance, was not added (referred to as pretreatment liquid b). In Example 2, pretreatment, treatment, and heat melting were performed in the same manner as in Example 2 except that the pretreatment liquid b was used instead of the pretreatment liquid a and the treatment liquid B was used instead of the treatment liquid A. Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1050 ° C. The obtained composite particle B2 was almost spherical and had a particle size of 500 μm, and contained heavy metals, boron and silicon.

Example 5
<Processing liquid C>
In Example 1, instead of using the silicone emulsion, 18 parts by mass of oily silicone (manufactured by Toray Industries, Inc., SH200), PAC (manufactured by Oji Paper Co., Ltd., “PAC” (containing 10 to 11% of aluminum in terms of aluminum oxide) 8 parts by weight of an aqueous solution), 40 parts by weight of a neutral detergent (made by Orient Shoji Co., Ltd., trade name: Almighty Clean) as a surfactant was added, and the silicone was dispersed by sufficiently stirring. An emulsion was obtained by emulsifying and dispersing well in an aqueous borax solution, and the emulsion thus obtained is referred to as Treatment Liquid C.

  Using the treatment liquid C, the treatment was performed in the same manner as in Example 1, followed by heating and melting. Two minutes after the start of heating, the sample surface reached 1100 ° C. (temperature difference from the furnace temperature: 350 ° C.). Uniform black glass particulate composite particles C1 were obtained. The obtained composite particles C1 were almost spherical, had a volume average particle size of 400 μm, and contained heavy metals, boron, carbon, and silicon.

Example 6
<Pretreatment liquid a, treatment liquid C>
In Example 2, except that the treatment liquid C was used instead of the treatment liquid A, pretreatment was performed with the pretreatment liquid a and treatment was performed with the treatment liquid C in the same manner as in Example 2. Heat melting was performed. Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1100 ° C. The obtained composite particle C2 was substantially spherical, had a volume average particle diameter of 400 μm, and contained heavy metals, boron, carbon, and silicon.

Example 7
<Pretreatment liquid d, treatment liquid D>
In Example 2, a pretreatment liquid d and a treatment liquid D were prepared using a 15 mass% borax aqueous solution in place of the 18 mass% borax aqueous solution, and further, unground pulverized dyeing sludge instead of pulverized iron slag. Except that was used, pretreatment, treatment, and heat melting were performed in the same manner as in Example 2. The volume average particle diameter of the unground crushed sludge was 700 μm.

  Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1100 ° C. The obtained composite particles D2 were almost spherical, had a volume average particle size of 500 μm, and contained heavy metals, boron, carbon, and silicon.

Example 8
<Pretreatment liquid e, treatment liquid E>
In Example 2, the pretreatment liquid e and the treatment liquid E were prepared using a 28 mass% borax aqueous solution instead of the 18 mass% borax aqueous solution, and further, the crushed slag was used instead of the iron slag. In the same manner as in Example 2, pretreatment, treatment, and heat melting were performed. The particle size of the crushed slag after pulverization was 1 mm to 3 mm.

  Although the furnace temperature was 750 ° C., the temperature of the sample surface had reached 1100 ° C. At this time, the whole sample was red hot after 2 minutes of heating and melting, and the surface frame was generated for 3 minutes and terminated. The obtained composite particle E2 was almost spherical, its particle size was 0.3 mm to 0.5 mm, and contained heavy metals, boron, carbon, and silicon.

Example 9
<Pretreatment liquid f, treatment liquid F>
In Example 2, it replaced with 18 mass% borax aqueous solution, and prepared the pretreatment liquid f using 30 mass% borax aqueous solution.

  20 parts by mass of scatterable asbestos was added to 100 parts by mass of the pretreatment liquid f prepared above, and kept at 95 ° C. for 20 minutes.

  Next, this liquid (pretreatment liquid f in which diffusible asbestos is dispersed) is cooled from 95 ° C. to 20 ° C., and the same silicone emulsion as in Example 1 is used in this liquid as in the case of Treatment liquid A in Example 1. In addition to the silicone concentration, treatment liquid F was prepared and impregnated with diffusible asbestos.

  Next, heating is continued to remove excess moisture, and when the excess moisture disappears, a hand burner having a low temperature of about 1000 ° C. is indirectly flamed for 5 seconds so as to correspond to a furnace temperature of 600 ° C. or higher. A glass ball close to 2 was formed (composite particle J1 was formed). Harmless asbestos was surrounded by molten borax and detoxification was achieved. In addition, when the same treatment was performed with chrysotile and crocidolite instead of asbestos, the same result as that of the scattering asbestos was obtained (composite particle J2 was formed from chrysotile, and composite particle J3 was formed from crocidolite).

Example 10
<Pretreatment liquid f, treatment liquid F>
In Example 9, the treatment liquid F in which diffusible asbestos was dispersed was retained at 70 ° C. for 60 minutes and impregnated, and then charged and dropped into a tower kiln type production furnace (gravity type fall production furnace) instead of a hand burner. . A spherical glass ball (referred to as “composite particle F2”) having a volume average particle diameter of 0.7 mm was obtained continuously in a short time. The composite particle F2 contained magnesium, boron, and silicon.

Example 11
<Pretreatment liquid g, treatment liquid G>
120 parts by mass of borax and 280 parts by mass of water were heated at 97 ° C. until all of the borax was dissolved, thereby preparing a pretreatment liquid g. In this heated pretreatment liquid g, 50 parts by mass of finely pulverized iron slag having a particle size of 1 mm to 2 mm is added and maintained at 97 ° C. for 10 minutes with stirring, so that the iron slag is impregnated with the pretreatment liquid g. It was.

  When heating of the pretreatment liquid g was stopped and the temperature reached 30 ° C., 50 parts by mass of polyaluminum chloride (manufactured by Oji Paper Co., Ltd., “PAC” (aqueous solution containing 10 to 11% aluminum in terms of aluminum oxide) was added. The mixture was further stirred, and 50 parts by mass of oxime type silicone (manufactured by Toray Industries, Inc., SH5070) was added, followed by stirring for 5 minutes until uniform, thereby preparing treatment liquid G in which iron slag had already been immersed. After the partial treatment, the treatment liquid G was impregnated in the steel slag.

  Next, these were transferred to a heating furnace and heated and melted for 15 minutes. The temperature in the heating furnace after the water was evaporated was 750 to 760 ° C., and the surface temperature of the heated and melted object was 1100 ° C.

  Because of the large amount of PAC, gray-colored composite particles G2 were obtained instead of black. The composite particle G2 contained metals (including aluminum), boron, and silicon.

Example 12
<Pretreatment liquid h, treatment liquid H>
120 parts by mass of borax was added to 280 parts by mass of water and heated at about the boiling point (100 ° C.) until all the borax was dissolved. 50 parts by mass of mineral slag pulverized to a volume average particle diameter of 1 mm was added to the obtained pretreatment liquid h, and the mineral slag was impregnated with the pretreatment liquid h while heating at 100 ° C. for 10 minutes. Then, 100 mass parts of 50 mass% sugar water was added, and also it heated for 3 minutes.

  Heating was stopped when the water was evaporated and the viscosity increased, and 35 parts by mass of wood chips serving as a carbon source was added to adsorb excess water. 100 parts by mass of “silicone dispersion S” prepared below was mixed at 30 ° C. with 50 parts by mass of the borax impregnated mineral slag dispersion (pretreatment liquid containing mineral slag). Let the obtained liquid be the processing liquid H.

[Preparation of Silicone Dispersion S]
100 parts by mass of naphthenic mineral oil, polyaluminum chloride (manufactured by Oji Paper Co., Ltd., “PAC” (aqueous solution containing 10 to 11% of aluminum in terms of aluminum oxide), silicone as SE792 (manufactured by Dow Corning Toray) 170 parts by mass of the main component of the two-component silicone sealant) was stirred while heating, and further 100 parts by mass of the above polyaluminum chloride aqueous solution (PAC) was added thereto. Liquid S "was prepared.

  The treatment liquid H containing the mineral slag was allowed to stand at 20 ° C. for 12 hours and then heated at a furnace temperature of 500 to 750 ° C. to be melted by heating. At this time, a large pyroframe was generated to obtain black glassy composite particles H2. The composite particle H2 is a composite particle containing a metal (including aluminum), boron, carbon, and silicon having a volume average particle size of 300 μm.

  As will be described later, the composite particles H2 floated on water and were extremely excellent in water repellency. In addition, when observed with a microscope, it can be seen that the mineral slag is surrounded by vitreous, and the compound containing Si (silicon) and B (boron) penetrates into the mineral slag and stabilizes over time for a long time. I found out that it was done.

Example 13
<Pretreatment liquid h, treatment liquid H>
In Example 12, composite particles H2 ′ were obtained in the same manner as in Example 12 except that crushed slag was used instead of the slag. As will be described later, this composite particle H2 ′ floated on water and was extremely excellent in water repellency. In addition, when observed with a microscope, it can be seen that the slag is surrounded by vitreous, and the compound containing Si (silicon) and B (boron) penetrates into the slag and stabilizes over time for a long time. I found out that it was done.

Evaluation Example 1
<Evaluation of stability, detoxification, and low toxicity>
The composite particles obtained in all the above examples were subjected to the dissolution test method according to Notification No. 13 of the Environment Agency. Specifically, 100 g of each of the composite particles obtained in each example was infiltrated into 10 times the amount of water for 6 hours (naturally left), filtered through a 1 μm filter, and the components contained in the filtrate obtained at this time The stability, detoxification, and low toxicity of the composite particles were determined according to the following criteria.
◎: Metal content is very low ○: Metal content is low ×: Metal content is high

The analysis results of the filtrate obtained when the composite particles obtained in Example 13 were subjected to the above elution test method were as follows, and the content of metals contained in the iron slag was very low. . Furthermore, when the content of zinc was analyzed according to Environmental Agency Notification No. 14 (A), it was less than 0.01 g / L.
Fluoride: 0.5mg / L
Cadmium or a compound thereof: less than 0.005 mg / L alkylmercury compound: 0
Lead or its compound: Less than 0.02 mg / L Hexavalent chromium compound: Less than 0.04 mg / L Arsenic or its compound: Less than 0.01 mg / L Mercury or its compound: Less than 0.0005 mg / L Selenium or its compound: 0 Less than 0.01 mg / L Boron: 780 mg / L
Ammonia, ammonium compounds, nitrite compounds and nitrate compounds
: Less than 1 mg / L Chloride ion: 960 mg / L

  In other examples 2, 4 and 6 to 13, the metal content was very low, and in examples 1, 3 and 5, the metal content was low. That is, according to the particle processing method of the present invention, it was found that harmful metals were stabilized and the obtained composite particles were low in toxicity and harmless.

Evaluation example 2
<Evaluation of flame retardancy>
20 g of each of the composite particles obtained in all of the above examples was pressure-molded according to a conventional method, and a flame using butane as a combustion gas was indirectly flamed at the tip of the molded body for 60 seconds, but did not ignite. Moreover, it did not melt and was smokeless.

Evaluation Example 3
<Evaluation of chemical resistance>
Take 10 g of the composite particles obtained in all the above examples in a flask, add 100 g each of 1N (normal) dilute sulfuric acid, 5% by mass sodium hydroxide and acetone, and leave it at 20 ° C. for chemical reaction. The presence or absence of was observed visually.
○: No visual change ×: Visual change. For pigments containing pigments, some elution phenomena such as pigments are visually observed.

Evaluation Example 4
<Evaluation of water repellency>
10 g of the composite particles obtained in all the above examples were pulverized so that the volume average particle diameter was about 500 to 700 μm, dropped on 100 g of water, stirred in water, and the following determination was made.
○: Float in water ×: Sink in water

Evaluation Example 5
<Evaluation of antistatic properties>
The composite particles obtained in all the above examples were packed in an acrylic resin pipe having a diameter of 7 mm and a length of 200 mm, and tapped five times from a height of 2 cm. Thereafter, a DC voltage is applied from above and below the sample packed in the pipe, and the current value at 20 ° C. is measured. From the current value, the specific resistance in this shape of the powder packed in this shape was calculated. When the specific resistance was 10 ⁰ Ω · cm or less, the antistatic property “◯” was judged, and when the specific resistance was larger than 10 ⁰ Ω · cm, the antistatic property “x” was judged.

Evaluation Example 6
<Evaluation of heat resistance>
100 g of each composite particle obtained in all the above examples was heated in an electric furnace set to 500 ° C. The case where no change was found in both appearance and mass was judged as “◎”, and the case where almost no change was found was judged as “◯”.

Evaluation Example 7
<Evaluation of harmless acicular particles>
When the composite particles obtained in Example 9 and Example 10 were observed with an optical microscope, the needle-like portions peculiar to needle-like particles disappeared. Moreover, in Example 10, the same result was obtained even when chrysotile and crocidolite (FIG. 1) were used as the scattering asbestos which is an acicular particle.

  From the above results, when the particle treatment method of the present invention is used, the “metal-containing particles”, for example, waste particles, heavy metal-containing particles, and needle-like particle-containing particles are detoxified safely, simply, and inexpensively. be able to. Moreover, it is possible to obtain composite particles as valuable materials with excellent heat resistance; flame retardancy; chemical resistance to acids, alkalis, organic solvents, etc .; weather resistance; water repellency; Recyclable.

  The particle treatment method of the present invention can be applied to the treatment of waste, etc., to detoxify harmful metals and to obtain composite particles having excellent heat resistance, etc. can do. The composite particles of the present invention are excellent in heat resistance; flame retardancy; conductivity; chemical resistance to acids, alkalis, organic solvents, etc .; antistatic properties; weather resistance; water repellency; Carbon, incombustible carbon black, incombustible fireproof building materials, activated carbon, toxic substance adsorbents, molecular sieves, antifriction materials, UV inhibitors, pigments, C / C composite super heat resistant filler, rubber reinforcement, asphalt heat improver, soil improver Etc. are widely used. In addition, the particle processing method of the present invention is free from the scattering of toxic particles during processing, and the obtained one can be used effectively, so that the total cost of waste processing is reduced and widely used in the above fields. It is.

  This application is based on Japanese Patent Application No. 2008-288555, which is a Japanese patent application filed on November 11, 2008, the entire contents of which are cited herein as disclosure of the specification of the present invention. It is taken in.

Claims (14)

  A particle treatment method comprising: impregnating a metal-containing particle with a treatment liquid containing at least borax, silicone, and water, followed by heating and melting at a furnace temperature of 600 ° C. or higher.   The particle treatment according to claim 1, wherein the particles containing the metal are impregnated with the pretreatment solution containing borax and water at 60 ° C or higher before the particles containing the metal are impregnated with the treatment liquid. Method.   The particle treatment method according to claim 1 or 2, wherein the treatment liquid and / or the pretreatment liquid contains 15 parts by mass or more of borax in a dissolved state with respect to 100 parts by mass of water.   The above treatment liquid and / or the pretreatment liquid is obtained by heating at least borax and water to the boiling point of the obtained borax aqueous solution to completely dissolve the borax in water. The particle processing method according to claim 3.   The particle processing method according to any one of claims 1 to 4, wherein the treatment liquid and / or the pretreatment liquid further contains a water-soluble organic substance.   The particle processing method according to claim 5, wherein the water-soluble organic substance is a saccharide.   The particle processing method according to any one of claims 1 to 6, wherein the metal-containing particles are waste particles.   The particle processing method according to claim 7, wherein the waste particles are heavy metal-containing particles.   The particle processing method according to claim 7, wherein the waste particles are acicular particle-containing particles.   The particle processing method according to any one of claims 1 to 9, wherein the metal-containing particles further contain an organic chlorine compound.   The particle processing method according to any one of claims 1 to 10, wherein the processing liquid further contains polyaluminum chloride.   The particle processing method according to claim 1, wherein the heat melting is performed in an oxygen-containing gas atmosphere.   The particle processing method according to any one of claims 1 to 12, wherein a carbonaceous material remains in a product obtained by heating and melting.   A composite particle obtained by using the particle processing method according to any one of claims 1 to 13 and containing metals, boron, carbon and silicon.