JP5834380B2 - Method for treating lead-containing glass and treatment agent for lead-containing glass - Google Patents

Description

  The present invention relates to a method for treating lead-containing glass waste and a treatment agent for lead-containing glass. In particular, the present invention relates to a treatment method for lead-containing glass easily, efficiently, and safely, so that lead is not eluted. The present invention relates to a treatment method and a treatment agent for preventing outflow.

  Since glass with increased transparency called glass or crystal glass used for TV and OA equipment cathode ray tubes contains lead, when disposing of these lead-containing glasses, lead from the lead-containing glass Dissolution becomes a problem. In particular, elution of lead from lead-containing glass becomes more prominent when it comes into contact with alkaline liquids for a long time or when the surface area is increased by crushing the glass for disposal to form fine particles. . For this reason, when landfilling such a lead-containing glass waste, it is necessary to perform a process for preventing the elution of lead.

  Conventionally, as a technique for preventing elution of heavy metals such as lead, Patent Document 1 proposes a method for insolubilizing heavy metals in which water-soluble phosphoric acid is added to fly ash. It is premised on the presence of functional calcium and cannot be applied to the treatment of an object to be treated that does not contain calcium such as lead glass.

  Patent Document 2 proposes a lead elution prevention technique in which a phosphate-based drug is added to a slag solidified product alone or in combination with a phosphate-based drug and a lime-based drug. The selection method of acid and calcium compounds, and the optimal prescription are not explained. In the case of lead-containing glass, a single use of a phosphate-based drug considered preferable in Patent Document 2 or a phosphate-based drug and a lime-based drug In some cases, sufficient insolubilization treatment could not be performed even in the combined treatment.

  Patent Document 3 proposes to insolubilize lead by adding a magnesium salt alone to a lead-containing glass waste, or a combined addition of magnesium salt or calcium salt and phosphoric acid, or addition of alumina cement. These chemicals need to be used in solid or slurry form, and it is difficult to uniformly disperse them on the surface of the crushed glass like liquids, and thus it is difficult to obtain a stable insolubilizing effect. Patent Document 3 does not mention a method of treating with a calcium salt alone.

Japanese Patent Publication No.4-1710 JP-A-2005-329400 JP 2001-293463 A

  It is an object of the present invention to provide a treatment method and a treatment agent for treating lead-containing glass waste easily, efficiently and safely and reliably preventing elution or outflow of lead from the treated product. .

  As a result of repeated investigations to solve the above problems, the present inventors have obtained a good insolubilizing effect that can clear lead elution standards by adding neutral calcium salts to lead-containing glass waste. Furthermore, it has been found that by using a phosphoric acid compound in combination, the stability of the lead insolubilized product is improved, and a further advanced lead elution or outflow prevention effect can be obtained.

  The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

[1] In the processing method of the lead-containing glass waste for preventing elution of lead from lead-containing glass waste, lead-containing glass waste, lead to mixing a water soluble calcium compound other than calcium chloride or calcium chloride A method for treating glass waste, wherein the water-soluble calcium compound other than calcium chloride is at least one selected from calcium sulfate, calcium phosphate (first calcium phosphate, second calcium phosphate, third calcium phosphate), and calcium carbonate. The processing method of the lead containing glass waste characterized by the above-mentioned. However, in the case of mixing a water-soluble calcium compound other than calcium chloride, the case of further mixing with a phosphate compound is excluded.

[2] A method for treating lead-containing glass waste for preventing elution of lead from lead-containing glass waste, wherein the lead-containing glass waste is mixed with calcium chloride and a phosphate compound. Processing method for lead-containing glass waste.

[3] The method for treating lead-containing glass waste according to [2], wherein the phosphate compound is a second phosphate.

[ 4 ] A treatment agent for preventing elution of lead from the lead-containing glass, the treatment agent for lead-containing glass containing calcium chloride.

[5] A treatment agent for preventing elution of lead from the lead-containing glass, the treatment agent for lead-containing glass containing calcium chloride and a phosphate compound .

  According to the present invention, lead-containing glass waste can be treated easily, efficiently, and safely, and lead in lead-containing glass waste, which has been difficult to fix with conventional lead fixing agents, is effectively removed. It is possible to reliably prevent elution or outflow of lead from the processed material.

  Embodiments of the method for treating lead-containing glass waste and the treatment agent for lead-containing glass of the present invention will be described in detail below.

[Treatment method of lead-containing glass]
The processing method of the lead-containing glass of the present invention is a lead-containing glass waste,
(1) Calcium chloride
(2) A water-soluble calcium compound other than calcium chloride is added and mixed. (1) When calcium chloride is added, a phosphate compound may be used in combination with calcium chloride.

<Action mechanism>
In the present invention, details of the insolubilization mechanism of lead in lead-containing glass waste by using calcium chloride or a water-soluble calcium compound other than calcium chloride have not been fully elucidated, but lead eluted from lead-containing glass waste There are ionic and fine particle types, and calcium chloride and water-soluble calcium compounds other than calcium chloride are assumed to be fixed in a form that adsorbs fine particle lead and does not elute. Is done. Furthermore, when a phosphoric acid compound is added in combination with calcium chloride, fine lead is insolubilized by the above-mentioned mechanism, and it is combined with ionic lead to mineralize it, resulting in a higher insolubilizing effect. Presumed to be obtained.

Since lead has the best insolubilizing effect in the neutral range of pH 8 to 10, the properties of the drug to be added greatly affect the elution pH for the lead elution preventing effect.
Since the lead-containing glass waste to be treated in the present invention does not have pH buffering properties like incinerated ash and slag crushed material, the influence of the added chemicals appears greatly. Accordingly, neutral to weakly acidic or weakly alkaline calcium chloride and water-soluble calcium compounds other than calcium chloride are effective as the calcium compound to be added.

  In addition, a powdery drug is uniformly applied to the surface of lead-containing glass waste containing various fragments, such as coarse particles to finely pulverized products, such as waste made by crushing lead-containing glass. Therefore, it is difficult to sufficiently exhibit the lead insolubilizing effect. Therefore, in the present invention, the chemical added to the lead-containing glass waste is preferably used in liquid form, and particularly preferably used as an aqueous solution.

<Lead-containing glass waste>
The lead-containing glass waste to be treated in the present invention is usually about 5 to 20 mm in thickness and 1 to 1 in diameter when discarding lead-containing glass such as a cathode ray tube, a liquid crystal display panel, and crystal glass of a television or OA equipment. It is a crushed glass crushed to about 200 mm.

<Water-soluble calcium compounds other than calcium chloride and calcium chloride>
In the present invention, the water-soluble calcium compound other than calcium chloride includes, as described above, calcium sulfate, calcium phosphate (primary calcium phosphate, second calcium phosphate, third calcium phosphate in that the pH is neutral or weakly acidic or weakly alkaline. ), Calcium carbonate is preferred, and calcium sulfate is particularly preferred because it exhibits neutrality that does not affect the pH due to fluctuations in the amount of its own addition.

  Thus, calcium chloride is also preferable in that it is neutral without affecting the pH due to fluctuations in the addition amount of itself.

In addition, water-soluble calcium compounds other than calcium chloride may be used alone or in a combination of two or more in any combination and ratio.
It is also possible to use calcium chloride and a water-soluble calcium compound other than calcium chloride in combination, but in the present invention, when a water-soluble calcium compound other than calcium chloride is used, the phosphoric acid compound described below is not used. And

  As described above, calcium chloride is preferably used as an aqueous solution as described above. In this case, the concentration of calcium chloride in the aqueous solution can be arbitrarily set, but is preferably about 1 to 40% by weight. Water-soluble calcium compounds other than calcium chloride have relatively low solubility in water and are difficult to use as high-concentration aqueous solutions, and are usually used in the form of powder or suspension.

<Phosphoric acid compound>
In the present invention, when processing lead-containing glass waste using calcium chloride, when a phosphate compound is used in combination, the lead insolubilization effect is stabilized, and the elution or outflow of lead from the processed product is further ensured. Can be prevented.

  As the phosphoric acid compound to be used in combination, phosphoric acid or a salt thereof can be used. As phosphoric acid, orthophosphoric acid, hypophosphorous acid, metaphosphorous acid, pyrophosphorous acid, orthophosphorous acid, hypophosphorous acid, etc. Examples include acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and condensed phosphoric acid. Examples of the phosphate include first to third sodium phosphates, first to third potassium phosphates, and first to third calcium phosphates. 1st to 3rd alkali metal salts and 1st to 3rd alkaline earth metal salts of phosphoric acid, but, like calcium chloride, it is difficult to affect the pH due to fluctuations in the amount of its own addition, Phosphate salts such as first to third sodium phosphates, first to third potassium phosphates, first to third calcium phosphates are preferred, more preferably second alkali metal phosphates and second alkaline earth phosphates. Secondary phosphates such as metal salts are preferred Ku, particularly preferably a sodium secondary phosphate.

  These phosphoric acid compounds may be used alone or in a combination of two or more in any combination and ratio.

  It is preferable to add the phosphoric acid compound as a liquid to the lead-containing glass waste, and it is particularly preferable to use it as an aqueous solution of about 0.1 to 85% by weight, such as handleability and uniform mixing with the lead-containing glass waste. In terms of surface.

<Processing method>
In the present invention, calcium chloride, a water-soluble calcium compound other than calcium chloride, or calcium chloride and a phosphate compound are preferably added to and mixed with lead-containing glass waste as an aqueous solution of an additive agent. Prevents the elution or outflow of lead from lead-containing glass waste.

  In addition, when the treatment is performed using two or more kinds of drugs in combination, such as when calcium chloride and a phosphate compound are used in combination, any of the drugs may be used first, and any of the drugs may be used later. At the same time, it may be added to the lead-containing glass waste, or one previously mixed to form a single agent may be used. When two or more kinds of drugs are mixed in advance to form a single agent, it is preferably used as a mixed liquid of a water-soluble calcium compound and a phosphate compound having a total drug concentration of about 2 to 60% by weight.

<Amount of drug added>
The amount of drug added to lead-containing glass waste varies depending on the type of drug used, the presence or absence of a phosphate compound in the case of calcium chloride, and the lead content of the lead-containing glass waste to be treated. Although it is determined appropriately to such an extent that an insolubilizing effect can be obtained, in the usual case, when only calcium chloride is added, the amount of calcium chloride added to lead-containing glass waste is 0.1 to 40% by weight, particularly 0.5 to 20%. It is preferable to set it as weight%.

  When calcium chloride and a phosphate compound are used in combination, the amount of calcium chloride added to the lead-containing glass waste is 0.1 to 40% by weight, particularly 0.5 to 20% by weight. The addition amount is 0.1 to 40% by weight, particularly 0.5 to 20% by weight, based on the lead-containing glass waste, and the total addition amount of calcium chloride and phosphate compound is 0.2 to 80% by weight, In particular, it is preferable to add 1 to 40% by weight.

  Moreover, when adding water-soluble calcium compounds other than calcium chloride, the amount of water-soluble calcium compounds other than calcium chloride added to lead-containing glass waste is 0.1 to 40% by weight, particularly 0.5 to 20% by weight. It is preferable. Also when calcium chloride and a water-soluble calcium compound other than calcium chloride are used in combination, it is preferable that the total addition amount of these is in the above range.

  In either case, if the amount of drug added is too small, sufficient lead insolubilization effect cannot be obtained, and if it is too much, improvement of other insolubilization effects cannot be expected, and the amount of drug addition increases and it is not economical. .

[Treatment agent for lead-containing glass]
The treatment agent for lead-containing glass of the present invention contains calcium chloride and is usually provided as an aqueous solution of about 1 to 50% by weight of calcium chloride.

The treatment agent for lead-containing glass of the present invention may contain calcium chloride and the above-described phosphate compound. In this case, an aqueous solution of about 1 to 30% by weight of calcium chloride and a phosphate compound Of 1 to 30% by weight of an aqueous solution containing 1 to 30% by weight of calcium chloride and 1 to 30% by weight of a phosphoric acid compound. It may be a single agent.
Moreover, the treatment agent for lead-containing glass of the present invention may be provided in a powder form and used as an aqueous solution in use.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

  In the following, as the lead-containing glass waste to be treated, lead glass containing lead was crushed into small pieces having a thickness of 5 to 10 mm and a diameter of 10 to 30 mm.

[Examples 1 to 5, Comparative Examples 1 to 4]
The amount of chemicals shown in Table 1 was added to the glass waste containing lead to be treated and mixed thoroughly with a spatula (however, no chemicals were added in Comparative Example 1). The dissolution test of Environmental Agency Notification No. 13 in 1968 was conducted to measure pH and lead elution, and the results are shown in Table 1.

  From Table 1, the following is clear.

In the untreated Comparative Example 1, the Pb elution amount was 3.0 mg / L, whereas in Example 1 to which a neutral 35 wt% aqueous second calcium chloride solution was added, the Pb elution amount was 0.07 mg / L. L and the landfill standard of 0.3 mg / L were cleared. In Example 2 in which a neutral 30 wt% dibasic potassium phosphate aqueous solution was used in combination with the 35 wt% dibasic calcium chloride aqueous solution, a further lead elution prevention effect was obtained. In Example 2, the addition order of the second calcium chloride aqueous solution and the second potassium phosphate aqueous solution was the order of the second calcium chloride aqueous solution and the second potassium phosphate aqueous solution.
In Example 3 to which calcium carbonate was added, the Pb elution amount was 0.03 mg / L.
In Example 4 to which calcium sulfate was added, the Pb elution amount was 0.01 mg / L.
In Example 5 to which dicalcium phosphate was added, the Pb elution amount was 0.01 mg / L.

On the other hand, in Comparative Example 2 in which only the 30 wt% dibasic potassium phosphate aqueous solution was added, the elution preventing effect was not obtained.
Moreover, in the comparative example 3 which used together phosphoric acid and the slaked lime of a lime type | system | group chemical | medical agent, there existed the case where the elution prevention effect was acquired (1st time), and the case where it was not obtained (2nd time). This is because it is difficult to uniformly apply a powder medicine such as a lime-based medicine to the crushed glass, and the effect varies.

  As described above, according to the present invention, the elution or outflow of lead from lead-containing glass waste is reliably prevented by using calcium chloride, calcium chloride and a phosphate compound, or a water-soluble calcium compound other than calcium chloride. You can see that you can.

Claims (5)

  Lead-containing glass waste in which lead-containing glass waste is mixed with calcium chloride or a water-soluble calcium compound other than calcium chloride in the processing method for lead-containing glass waste to prevent lead elution from lead-containing glass waste A method for treating a product, wherein the water-soluble calcium compound other than calcium chloride is at least one selected from calcium sulfate, calcium phosphate (first calcium phosphate, second calcium phosphate, third calcium phosphate), and calcium carbonate. A method for treating lead-containing glass waste. However, in the case of mixing a water-soluble calcium compound other than calcium chloride, the case of further mixing with a phosphate compound is excluded.   A lead-containing glass characterized by mixing calcium chloride and a phosphoric acid compound with lead-containing glass waste in a method for treating lead-containing glass waste to prevent elution of lead from lead-containing glass waste Waste disposal method.   3. The method for treating lead-containing glass waste according to claim 2, wherein the phosphate compound is a second phosphate.   A treatment agent for preventing elution of lead from lead-containing glass, the treatment agent for lead-containing glass containing calcium chloride.   A treating agent for preventing elution of lead from lead-containing glass, the treating agent for lead-containing glass containing calcium chloride and a phosphate compound.