JPS62114661A - Preparation of cation trapping agent - Google Patents

Abstract

PURPOSE:To inexpensively and effectively, obtain cation trapping agent, by applying acid treatment to a slurry containing shaft furnace slag or fly ash dispersed therein as industrial waste to elute an alkaline earth metal component in a liquid phase and separating the slag or the like from the slurry to wash the same. CONSTITUTION:When a starting stock material is shaft furnace slag, the shaft furnace slag is dispersed in water or an aqueous alkali metal salt solution as an aqueous dispersing solvent to prepare a shaft furnace slag slurry. Next, the slurry is treated with 1-5N hydrochloric acid to adjust the pH thereof to 3-7 to elute calcium oxide and magnesium oxide in the shaft furnace slag in the liquid phase of the slurry without excessively destructing the internal structure of the slag. The obtained acid treated shaft furnace slag is separated from the slurry and washed to obtain a desired cation trapping agent. Fly ash can be treated in the same way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a cation scavenger,
The cation scavenger obtained by the production method of the present invention has the ability to capture cations, especially calcium ions and magnesium ions, so it can be added to synthetic detergents as a water softener, and can be used for zeolite production. It is useful as a raw material.

[Conventional technology]

Conventionally, phosphoric acid compounds and the like have been added to synthetic detergents as water softeners to capture cations such as calcium ions and magnesium ions in order to enhance their detergent effects.

on the other hand,! ! ! In the iron industry, approximately 80 million tons of blast furnace slag is produced as a by-product annually, and the amount of fly ash discharged has been rapidly increasing recently.

[Problem that the invention seeks to solve]

However, phosphoric acid compounds are expensive, and their use in large quantities contributes to pollution, so various phosphorus-free detergents have been developed, and inexpensive and effective detergents with the ability to capture cations such as calcium ions and magnesium ions have been developed. There is a need for a cation scavenger that can absorb Furthermore, the above-mentioned blast furnace slag or fly ash is discarded as industrial waste, and its effective utilization has not been sufficiently attempted.

Therefore, an object of the present invention is to provide a cation scavenger that can meet the above requirements by utilizing the above industrial waste.

[Means for solving problems]

The present invention has the above-mentioned objectives: a first step of dispersing blast furnace slag or fly ash in an aqueous dispersion medium to obtain a blast furnace slag slurry or fly ash slurry; and a blast furnace slag slurry or fly ash slurry obtained in the first step. A second process in which alkaline earth metal components such as calcium oxide and magnesium oxide in the blast furnace slag or fly ash are eluted into the slurry liquid phase without significantly destroying the internal structure of the blast furnace slag or fly ash. and a third step of separating and washing the acid-treated blast furnace slag or acid-treated fly ash obtained in the second step from the slurry.The method for producing the cation scavenger of the present invention will be described in detail below with regard to its embodiments. do.

Incidentally, since blast furnace slag or fly ash, which is a starting material in the present invention, is used in exactly the same way in the present invention, the case where blast furnace slag is used as a starting material will be described below.

Furthermore, the embodiments of the present invention are broadly divided into cases where water or an aqueous solution of an alkali metal salt is used as the aqueous dispersion medium, and cases where an aqueous solution forming a complex with an alkaline earth metal element is used. A case where water or a water/8 solution of an alkali metal salt is used as the aqueous dispersion solvent will be described.

In carrying out the present invention, first, blast furnace slag is dispersed in water or an aqueous solution of an alkali metal salt to obtain a blast furnace slag slurry (first step).

The amount of water or aqueous solution of alkali metal salt used is preferably such that 5 to 30% of the blast furnace slag is dispersed in the slurry.

Moreover, as the aqueous solution of the alkali metal salt, it is preferable to use a sodium chloride aqueous solution, and in that case, it is preferable that the degree is 10 to 30%.

Next, the blast furnace slag slurry obtained in the first step is treated with acid, and the calcium oxide and magnesium oxide in the blast furnace slag are eluted into the slurry liquid phase without significantly destroying the internal structure of the blast furnace slag (second step). process).

In this second step, in order to melt the calcium oxide and magnesium oxide in the blast furnace slag into the slurry liquid phase without destroying the internal structure of the blast furnace slag, 1 to 5 N hydrochloric acid is used as the acid. using the above 1n
I Add 100 to 2,000 parts of the above hydrochloric acid to the slurry containing 100 parts by weight of furnace slag for 50 to 70 hours until the pH of the blast furnace slag slurry is 3 to 3.
7, preferably 5 to G. II in water or the above water/8 solution when pH exceeds 7.
The ion exchange reaction between Ca" Further, the preferable temperature of the blast furnace slag slurry at that time is preferably 5.0 to 80°C.

After that, the acid-treated blast furnace slag obtained in the second step.

is separated from the slurry and washed (third step).

In this third step, the acid-treated blast furnace slag obtained in the second step is separated from the slurry liquid phase. By washing with water, acid-treated blast furnace slag that can be used as the intended cation scavenger is obtained.

Next, a case will be described in which an EDTA aqueous solution, which is an aqueous solution that forms a mirror body with an alkaline earth metal element, is used as an aqueous dispersion medium.

In this case, in the first step, EDTΔwater/
Except for 8 water, 8 liquids, you can carry out the procedure as described in π1, but
El) As the TA aqueous solution, it is preferable to use one with a molar concentration of 0.05 to 0°2.
It is preferable to use 1,000 to 2.000 parts by weight per 0 parts by weight.

In addition, in the second step, in order to elute calcium oxide and magnesium oxide in the blast furnace slag into the slurry liquid phase without destroying the internal structure of the blast furnace slag, 1 to 5 N hydrochloric acid is used as the acid. 20 to 5 parts by weight of the above hydrochloric acid to 100 parts by weight of the above blast furnace slag slurry.
0 part was added to the blast furnace slag slurry over 3 to 5 hours so that the pH of the blast furnace slag slurry was 4 to 6, for example 4.5, and reacted at 20 to 50°C for 3 to 6 hours. It is preferable to let

Thereafter, if the third step is carried out in the same manner as described above, acid-treated blast furnace slag having the same cation-trapping ability as obtained in the above-mentioned step will be obtained.

The cation trapping agent obtained as described above is highly active and has cation exchange ability, and has the ability to trap cations, especially calcium ions and magnesium ions as it is. % sodium hydroxide solution at 50 to 110° C. for 5 to 50 hours, the ability to capture calcium ions and magnesium ions can be further enhanced.

The above-mentioned first to third steps and the effects in each step in the present invention can be explained, for example, as follows.

When blast furnace slag is dispersed in water, a small amount of hydrogen ions (H+) present in the water and calcium ions (
Ca2+) undergoes ion exchange, Ca1+ elutes into the liquid phase,
Since OH- is generated, it becomes alkaline. In order to proceed with this ion exchange reaction, (a method of neutralizing the OH- ions produced by al with acid (H") (when water or an aqueous solution of an alkali metal salt is used as the aqueous dispersion medium as described above), (Add the ED T A/8 solution and add the eluted Ca
A possible method is to use + as a calcium complex (in the case of using an aqueous solution that forms a complex with an alkaline earth metal element as an aqueous dispersion medium).

In the case of the above fat method, when blast furnace slag is dispersed in water, the slag slurry becomes alkaline. Therefore, an acid solution is added to the slurry to make it slightly acidic.

The slurry becomes alkaline again through ion exchange.

Then, add the acid solution again. This operation is repeated to elute the upper alkaline components from the blast furnace slag into the liquid phase without destroying the internal structure of the blast furnace slag. As the ion exchange progresses, a hydrate film is formed on the surface of the slag particles, making it difficult for the ion exchange reaction to proceed. Therefore, using water or 10-30% saline as an aqueous dispersion medium, maintain the slag slurry in which 5-30% blast furnace slag is dispersed at 50-80°C, and add 1-5 N hydrochloric acid until the pH of the slurry is 3-7. 5θ of Ca2+ and Mg2+ in the slag.
The desired cation scavenger is produced by reacting until 100% substitution occurs.

In the case of the above fbl method, in the blast furnace slag slurry,
The reaction equivalent of the upper alkali components in the slag, El) ′r
Even if r@ is added, if the pl+ of the slurry is 7.0 or more, the ion exchange reaction between the hydrogen ions (!l+) in the solution 1 and the calcium ions (Ca") in the slag will hardly proceed. When acid (H") is added to this slurry to lower the p)I of the slurry, ion exchange occurs between Ca"φ in the slag and H+ in the liquid phase, and Ca is eluted into the liquid phase. has EDTA, so Ca is Ca
-ET) TA, and 2 H+ is generated.

The generated 11s undergoes ion exchange with Ca1 in the slag.

This reaction is repeated until the reaction with the alkaline earth component in the slag is completed. At 30° C., if EDTA is added in a reaction equivalent amount to the alkaline earth component in the slag, and the pl+ of the slag slurry is set to 4.5, the reaction is completed in about 3 hours. In this way, the alkaline earth components in the blast furnace slag can be reduced to 1% without destroying the internal structure of the blast furnace slag.
After one reaction in which a scavenger substituted with 1+ can be produced, the hi scavenger and the liquid phase are separated in the third step, but the Ca-ED in the liquid phase is
If the pl+ of the solution is set to 3.0 or less, TA decomposes into EDTA and Ca2t, and EDTA precipitates, so the EDTA used in the reaction can be recovered.

〔Example〕

Next, the cation trapping agent of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 100 g of blast furnace slag was dispersed in 1 liter of water for 10 minutes to obtain a blast furnace slag slurry. Next, 1 liter of 1.0N hydrochloric acid was added to the slurry while maintaining the temperature at about 50'C. was added over 70 hours so that the pH of the slurry did not fall below 3, and the blast furnace slag was acid-treated.

Thereafter, acid-treated blast furnace slag was separated from this slurry and thoroughly washed to obtain a cation 1IIi scavenger of the present invention.

In order to observe the cation-trapping ability of this cation-trapping agent, we used it as a water softener to obtain 10 degree hard water (71 ppmca).
When 2.0 g was added to >100 mff, it showed a water softening rate of about 90% at this temperature, indicating that it had sufficient calcium ion trapping ability.

Example 2 100 g of blast furnace slag was dispersed in 30% sodium chloride water/8 solution 1z for 10 minutes to obtain blast furnace slag slurry. Next, while maintaining the slurry at about 50° C., 1.0N hydrochloric acid 1β was added to the slurry over a period of 30 hours so that the pH of the slurry did not fall below 3, thereby acid-treating the blast furnace slag. Thereafter, acid-treated blast furnace slag was separated from this slurry and thoroughly washed to obtain a cation scavenger of the present invention.

Example 3 100 g of blast furnace slag was mixed with 10 g of O, 1 mol EDTA aqueous solution.
1 was dispersed in 10 minutes to make blast furnace slag slurry.
Next, while maintaining the slurry at about 30'C, 3Qml of 1.5% hydrochloric acid was added to the slurry to adjust the pH of the slurry to 4.5, and the slurry was reacted for 3 hours to acid-treat the blast furnace slag. Thereafter, acid-treated blast furnace slag was separated from this slurry and thoroughly washed to obtain a cation scavenger of the present invention.

Example 4 100g of blast furnace slag was mixed with 1at of 30% sodium chloride water.
It was dispersed for 10 minutes in a mixed solution of 0.1 molar DTA, 1 volume of water, 10β, and a blast furnace slag slurry. Next, while maintaining the slurry at about 30°C, 1,5 molar hydrochloric acid (3Q mR) was added to the slurry to adjust the pH of the slurry to 4.5, and the slurry was reacted for 2 hours to form blast furnace slag. was treated with acid. Afterwards, the acid-treated blast furnace slag is separated from this slurry and thoroughly washed.
The cationic hti 1m agent of the present invention was then prepared.

〔Effect of the invention〕

According to the method for producing a cation scavenger of the present invention, a cation scavenger capable of capturing cations such as calcium ions and magmus ions can be provided at low cost by using industrial waste.

Claims (7)

[Claims] (1) A first step of dispersing blast furnace slag or fly ash in an aqueous dispersion medium to obtain a blast furnace slag slurry or fly ash slurry, and treating the blast furnace slag slurry or fly ash slurry obtained in the first step with an acid, a second step of eluting calcium oxide and magnesium oxide in the blast furnace slag or fly ash into the slurry liquid phase without significantly destroying the internal structure of the blast furnace slag or fly ash; and an acid-treated blast furnace obtained in the second step. A method for producing a cation scavenger, comprising a third step of separating slag or acid-treated fly ash from a slurry and washing it. (2) The method for producing a cation scavenger according to claim (1), wherein the aqueous dispersion medium is water or an aqueous solution of an alkali metal salt. (3) The method for producing a cation scavenger according to claim (2), wherein the alkali metal salt is sodium chloride. (4) The method for producing a cation scavenger according to claim (1), wherein the aqueous dispersion medium is an aqueous solution that forms a complex with an alkaline earth metal element. (5) The method for producing a cation scavenger according to claim (4), wherein the aqueous solution that forms a complex with an alkaline earth metal element is an EDTA aqueous solution or a sucrose aqueous solution. (6) The method for producing a cation scavenger according to claim (1), wherein the acid is added to maintain the pH of the blast furnace slag slurry or fly ash slurry at 3 to 7. (7) The method for producing a cation scavenger according to claim (1), wherein the acid is a mineral acid or an organic acid such as hydrochloric acid or nitric acid.