JP2006116389A - Fixing method for boron and fluorine and fixing agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing method for boron and fluorine capable of certainly capturing and fixing boron and fluorine, and to obtain a fixing agent composition. <P>SOLUTION: The fixing method for boron and fluorine is characterized in that at least one kind (A) selected from the group consisting of a compound of a rare-earth element and a compound of a group 4 element; and an aluminum compound (B) are added to an object to be treated and boron and/or fluorine in the object to be treated is fixed. The fixing agent for boron and fluorine comprises at least one kind (A) selected from the group consisting of the compound of the rare-earth element and the compound of the group 4 element; and the aluminum compound (B). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for immobilizing boron and fluorine, and an immobilizing agent composition.

  Incinerated ash, incinerated fly ash, molten fly ash, molten slag, coal ash, slag, sludge, contaminated soil, shredder dust, wastewater discharged from factories, underground contaminated water in landfills, etc. contain various harmful substances If heavy metals harmful to the human body are eluted into groundwater, rivers and seawater, serious environmental pollution may occur. For this reason, various laws have been established to regulate the elution amount of heavy metals below a certain value, or regulate the amount of heavy metals in water below a certain value. Conventionally, dithiocarbamic acid group, phosphoric acid group, carboxylic acid are used for the purpose of immobilizing heavy metals in solid waste such as fly ash to prevent elution, or to collect and remove heavy metals in waste water. It is proposed to immobilize heavy metals with a metal scavenger having a functional group such as a group, a carbamic acid group, a dithioic acid group, an aminophosphoric acid group, a thiol group, or a xanthate group (Patent Documents 1 to 9 etc.) .

JP 49-99978 JP 51-111756 A JP-A-64-90083 JP-A-1-99679 JP-A-2-6889 Japanese Patent Laid-Open No. 5-50055 JP-A-5-212382 JP-A-6-15280 JP-A-12-136371

  Lead, chromium, incineration ash, incineration fly ash, molten fly ash, molten slag, coal ash, mines, sludge, contaminated soil, shredder dust, waste water discharged from factories, underground contaminated water at landfill sites, etc. In addition to (III), heavy metals such as cadmium and copper, boron and fluorine are contained. In recent years, regulations similar to those for heavy metals are being provided for boron and fluorine. However, the above-described conventional metal scavengers can capture and immobilize heavy metals, but detoxify boron and fluorine below the environmental standard value or below the wastewater standard value. It was difficult.

  As a result of intensive studies to solve the above problems, the present inventors have found that boron and fluorine can be efficiently immobilized by using a rare earth element compound or a group 4 element compound in combination with an aluminum compound. It came to complete.

That is, the present invention
(1) At least one selected from the group consisting of rare earth element compounds and group 4 element compounds (A) and an aluminum compound (B) are added to the object to be treated, and boron and / or Or boron, characterized by immobilizing fluorine, a method for immobilizing fluorine,
(2) A boron / fluorine fixing agent composition comprising at least one (A) selected from the group consisting of a rare earth element compound and a group 4 element compound, and an aluminum compound (B) ,
Is the gist.

  The method of the present invention can reliably fix boron and fluorine, which have been difficult to fix with conventional metal scavengers, and can prevent environmental pollution due to elution of boron and fluorine.

  As the rare earth element group (A) used in the present invention, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and the like Elemental chloride, bromide, iodide, sulfide, fluoride, nitrate, carbonate, sulfate, acetate, oxalate, oxide, nitride, oxychloride, alkoxide, hydroxide, ammonium salt, These complex salts are exemplified. Typical examples include scandium chloride, scandium hydroxide, scandium sulfate, scandium nitrate, scandium oxide, scandium oxalate, yttrium iodide, yttrium fluoride, yttrium chloride, yttrium carbonate, yttrium nitrate, yttrium oxalate, hydroxide Yttrium, Yttrium sulfate, Yttrium oxide, Promethium chloride, Promethium hydroxide, Promethium sulfate, Promethium nitrate, Promethium oxide, Lanthanum sulfide, Lanthanum chloride, Lanthanum bromide, Lanthanum iodide, Lanthanum hydride, Lanthanum nitride, Shu Lanthanum acid, Lanthanum carbonate, Lanthanum hydroxide, Lanthanum sulfate, Lanthanum nitrate, Lanthanum oxide, Lanthanum acetate, Cerium chloride, Cerium carbonate, Cerium hydroxide, Cerium sulfate, Cerium oxide, cerium oxide, cerium acetate, praseodymium chloride, praseodymium nitrate, praseodymium oxide, praseodymium hydroxide, neodymium chloride, neodymium nitrate, neodymium carbonate, neodymium oxide, neodymium hydroxide, promethium chloride, promethium nitrate, promethium sulfate, promethium hydroxide , Samarium chloride, samarium nitrate, europium chloride, europium sulfate, gadolinium chloride, gadolinium nitrate, gadolinium hydroxide, terbium chloride, terbium carbonate, terbium hydroxide, dysprosium chloride, dysprosium nitrate, dysprosium oxide, holmium chloride, holmium nitrate, hydroxide Holmium, holmium oxide, erbium chloride, erbium nitrate, erbium sulfate, erbium hydroxide, thulium oxide, thulium hydroxide, yttrium chloride Rubiumu, ytterbium nitrate, lutetium chloride, lutetium oxide or a composite compound thereof, cerium, rare earth chloride, and the like that lanthanum was chemically treated to concentrate mainly containing. In addition, group 4 element compounds include chlorides, bromides, iodides, sulfides, fluorides, nitrates, carbonates, sulfates, acetates, oxalates, oxides, nitrides such as titanium, zirconium and hafnium. , Oxychlorides, alkoxides, hydroxides, ammonium salts, and complex salts thereof. Typical examples include zirconium chloride, zirconium carbonate, zirconium hydroxide, zirconium sulfate, zirconium nitrate, zirconium oxide, zirconium acetate, zirconium oxychloride, titanium chloride, titanium hydroxide, titanium oxide, hafnium chloride, hafnium oxychloride, Examples thereof include hafnium oxalate, hafnium hydroxide, or composite compounds thereof. The rare earth element compound and the group 4 element compound may be used alone or in combination of two or more. Among them, lanthanum, cerium, yttrium, neodymium, praseodymium, samarium and zirconium compounds are preferred. In particular, chlorides, nitrates, sulfates, carbonates, acetates, and oxalates of the above elements are preferable. Typical examples include lanthanum chloride, lanthanum nitrate, lanthanum acetate, lanthanum oxalate, cerium chloride, and cerium nitrate. Yttrium chloride, yttrium nitrate, yttrium sulfate, neodymium chloride, neodymium nitrate, neodymium sulfate, praseodymium nitrate, praseodymium chloride, praseodymium sulfate, samarium chloride, samarium nitrate, zirconium chloride and the like.

  Examples of the aluminum compound of group (B) include aluminum chloride, aluminum sulfate, aluminum nitrate, and polyaluminum sulfate, among which aluminum sulfate and polyaluminum sulfate are preferable, and aluminum sulfate is particularly preferable. Two or more aluminum compounds can be used in combination.

  In the method of the present invention, the rare earth element compound and / or the group 4 element compound of group (A) and the aluminum compound of group (B) are added to the object to be treated, and boron and / or Alternatively, fluorine is collected and immobilized. In the method of the present invention, either the compound of the group (A) or the compound of the group (B) may be added to the object to be treated first, or may be added as a fixing agent composition in which both are mixed. . Whether the compound of (A) group and the compound of (B) group are added separately or when they are added as a fixing agent composition in which both are mixed, the compound of (A) group and the compound of (B) group The ratio of is a weight ratio, preferably (A) group compound: (B) group compound = 99: 1 to 10:90. The amount added to the object to be treated is preferably 0.1 to 20 wt% in terms of the total amount of the compound of group (A) and the compound of group (B). The compound of group (A) and the compound of group (B) may be added as a solid such as powder, or may be added as an aqueous solution or slurry. When the object to be treated is a liquid such as waste water, boron and fluorine contained in the waste water can be removed by precipitating and separating insoluble matter generated by collecting boron and / or fluorine. Further, when the floc material to be processed is solid, if necessary, water can be further added and left still, or kneaded to fix boron and fluorine.

  The treated objects to be treated by the method of the present invention include waste water discharged from factories and research institutes, underground contaminated water at landfill sites, smoke washing drainage, incineration ash and incineration fly ash generated at garbage incineration sites. Examples include coal ash, slag, sludge, contaminated soil, and shredder dust generated when fuel coal is burned in molten fly ash, molten slag, thermal power plants, and the like.

Hereinafter, Examples 1 to 5 and Comparative Examples 1 to 6 illustrating the present invention in more detail with reference to Examples.
Sodium fluoride and boric acid were dissolved in water, and per 1 liter of simulated wastewater prepared to have a boron concentration of 100 mg / L and a fluorine concentration of 100 mg / L, a predetermined amount of group (A) shown in Table 1 Compound, an aluminum compound of group (B) was added and stirred for 30 minutes, then allowed to stand. The insolubilized material was No. After separating and removing with 5C filter paper (holding hole diameter: 1 μm), the boron and fluorine concentrations remaining in the wastewater were measured by the following method. The results are shown in Table 1.

Fluorine analysis method: JIS K 0102 factory drainage test method 34.1 Lanthanum-alizarin complexone photometric method Boron analysis method: JIS K 0102 factory drainage test method 47.3 ICP emission spectroscopy

※１：廃水に添加後の割合 (Table 1)

* 1: Ratio after addition to wastewater

Examples 6-10, Comparative Examples 7-12
With respect to 100 g of incinerated ash (fluorine content: 4100 mg / kg, boron content: 350 mg / kg) when paper sludge or plastic is incinerated in a rotary kiln, a predetermined amount of a compound of group (A) shown in Table 2 ( The aluminum compound of group B) and 30 g of water were added and kneaded for 15 minutes. Table 2 shows the results of measuring the boron elution concentration and fluorine elution concentration in accordance with the Environmental Agency Notification No. 46 test for the treated and untreated incineration ash.

※２：飛灰に添加後の割合 (Table 2)

* 2: Ratio after adding to fly ash

Claims (2)

At least one selected from the group consisting of a rare earth element compound and a group 4 element compound (A) and an aluminum compound (B) are added to the object to be treated, and boron and / or fluorine in the object to be treated are added. A method for immobilizing boron and fluorine, characterized by immobilization. A boron and fluorine fixing agent composition comprising at least one (A) selected from the group consisting of a rare earth element compound and a group 4 element compound, and an aluminum compound (B).