KR101908090B1 - Method for producing inorganic flocculant for water treatment for fluorine removal - Google Patents

Abstract

The present invention relates to a preparing method of an inorganic coagulant for water treatment to remove fluorine. According to the present invention, the inorganic coagulant for water treatment comprises aluminum sulfate as an active substance. When the inorganic coagulant for removing fluorine is used to remove fluorine occurring in industrial waste water, chlorine ions occurring in treatment with polychloride aluminum can be minimized such that response to environmental regulations (e.g. regulated to be 500 ppm or less in China) can be enabled. In the meantime, compared to polyaluminum chloride, the inorganic coagulant has excellent efficiency of removing fluorine, relative to content of Al_2O_3. Furthermore, contrary to the conventional inorganic coagulant for water treatment, which is aluminum sulfate liquid, the coagulant of the present invention comprising aluminum sulfate liquid as an active substance can prevent freezing occurring in transportation and storage in a freezing season to make transportation and storage ready. In addition, occurrence of scale in using aluminum sulfate can be minimized.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing inorganic flocculants for water treatment,

The present invention relates to a method for producing an inorganic flocculant for water treatment for removing fluorine, and more particularly, to an inorganic flocculant for water treatment using aluminum sulfate as an effective ingredient, It is possible to minimize the chlorine ion generated by the treatment with polychlorinated aluminum when used, and to cope with the environmental regulations (for example, in the case of China, it is regulated to be 500 ppm or less), while the fluorine removal efficiency is also improved by Al ₂ O ₃ It is possible to obtain excellent effect compared to the content and to prevent the freezing (precipitation) phenomenon occurring during transportation and storage of the aluminum sulphate liquid during the winter season, so that it can be easily transported and stored, while minimizing scale occurring when using aluminum sulphate And a method for producing an inorganic flocculant for water treatment for removing fluorine.

Generally, along with the development of industry, various environmental pollutants such as wastewater are generated in large quantities. Due to such environmental pollutants, air pollution and water quality and soil pollution are becoming serious situations. Such environmental pollutants And efforts to effectively treat and reduce the industrial wastes generated by industrial activities have also been recognized as important tasks.

Industrial wastes that occupy most of the above-mentioned environmental pollutants include waste acids, waste alkalis, waste oil, sludge, waste asbestos, waste pesticides, waste synthetic polymer compounds and the like. Also, considerable effort and cost are required.

In particular, techniques for treating wastewater use chemical agglomeration, microbial treatment, ion exchange, adsorption, and oxidation.

In the case of using inorganic flocculants alone, the flocculants and dissolved organic substances are not properly removed in the flocculation process even when the amount of the inorganic flocculants used is increased, although the inorganic flocculant or the aluminum salt inorganic flocculant is widely used for the chemical flocculation In order to solve this problem, it is necessary to increase the load of the high-level water treatment, which causes the side effect of increasing the tap water price. In particular, in the case of the summer when the turbidity of the raw water is temporarily increased due to the factors such as flood, or the pH is significantly changed, there is a problem that effective coagulation is difficult with the inorganic flocculant alone.

In addition, when aluminum based inorganic coagulant is used, residual aluminum is present in the treated water, but aluminum is reported to cause brain diseases such as senile dementia called Alzheimer's disease.

In Korea, since 1996, the concentration of aluminum in drinking water is regulated below 0.2 mg / ℓ, and there is a limitation in using a large amount of aluminum-based inorganic coagulant for wastewater treatment.

In the case of iron chloride inorganic coagulants, coloring phenomenon and large amount of sludge are generated when the water is used excessively, causing the smell by the iron bacteria or depositing in the pipe causing the scale .

On the other hand, fluorine is used for various chemical reactions because of its strong chemical activity. Particularly, wastewater discharged from an electronic component factory using fluorine compounds for cleaning and etching of products contains a large amount of fluorine in the form of sodium fluoride (NaF), aluminum fluoride (AlF3), hydrogen fluoride (HF) There is a lot of difficulty in the treatment of wastewater. With regard to the discharge of fluoride as mentioned above, the discharge standard is set to 15ppm or less in the Water Environment Conservation Act, and gaseous fluoride is regulated by the Air Quality Preservation Act.

Examples of the method of treating wastewater containing fluoride include a method of using ion exchange resin and porous alumina, a precipitation method using Ca compound and Al compound, a precipitation method using rare earth compound, and the like. The ion exchange resin and porous alumina The method used is difficult to apply to industrial wastewater due to the limit of exchange capacity, and the precipitation method using Ca and Al or rare earth compounds is mainly used for removing fluorine ions from wastewater.

However, when fluorine is removed by using Ca and Al compounds, it is possible to remove COD (chemical oxygen demand, chemical oxygen demand) in addition to fluorine, but there is a disadvantage in that the fluorine ion removal efficiency is low and the amount of chemical input is large and the amount of sludge is generated .

In addition, the method using a rare earth compound is excellent as a fluorine ion removing agent because the fluorine ion removal efficiency is high and the amount of chemical input and the amount of treatment residue are small, but the efficiency of removing COD from the wastewater is insufficient.

Therefore, in order to remove COD simultaneously with fluorine by introducing a rare earth element in the wastewater, there is a disadvantage in that a large amount of expensive rare earth element must be added, and if a separate water treatment chemical for removing COD is used, the process becomes complicated and the equipment becomes enormous There are many problems.

On the other hand, recently, a method of removing fluorine from wastewater which can stably remove fluorine by using a reducing slag of an electric furnace when treating wastewater containing high concentration of fluorine is disclosed in Patent Document 1 (Korean Patent No. 0984448 2010.09.20. Registration).

The present invention also provides a method of recovering fluoride from wastewater, comprising: a first step of collecting fluorine-containing wastewater into a charging tower and then introducing a reducing slag of an electric furnace into the charging tower to precipitate and remove fluorine in the wastewater in the form of fluorite (CaF ₂ ); A second step of injecting wastewater from the first step into a reaction coagulation bath 40 and adding calcium hydroxide (Ca (OH) ₂ ) to coagulate and precipitate the remaining fluorine in the wastewater; And a third step of discharging the wastewater to the settling tank 50 and discharging only the supernatant after the second step is performed.

However, in the case of the above-described method for removing fluorine from wastewater, facilities such as a filling tower, a reactive coagulation tank, and a settling tank for treatment of wastewater containing fluorine at a high concentration are required and the economical burden is increased. The working efficiency and the fluorine removal efficiency due to the introduction of the reducing slag and the calcium hydroxide (Ca (OH) ₂ ) in the electric furnace for the first and second stages are extremely low.

Therefore, among the inorganic coagulants mainly used for chemical coagulation by the method of removing fluorine ions generated from industrial wastewater, aluminum chloride inorganic coagulants are still widely used.

Aluminum chloride-based inorganic coagulants such as aluminum chloride and aluminum sulfate are widely used, but polychlorinated aluminum has limitations due to excessive occurrence of chlorine (Cl) ions generated incidentally.

Therefore, it is appropriate to use aluminum sulfate which does not generate chlorine ions. However, such aluminum sulfate has limitations such as the storage stability, the phenomenon of freezing (precipitating) in the winter season, and the occurrence of scale overrun after use.

Therefore, aluminum sulfate is applied as an inorganic coagulant for fluorine removal, but when it is used as an inorganic coagulant for fluorine removal for treating fluorine generated in industrial wastewater, it minimizes chlorine ion generated by treatment with polychlorinated aluminum, : In the case of China, it is regulated to be less than 500ppm). In addition, compared to polychlorinated aluminum, the fluorine removal efficiency is also superior to the Al ₂ O ₃ content, and the aluminum sulphate liquid is freezing Precipitation) phenomenon, thereby facilitating transportation and storage. Further, research and development of a method for producing an inorganic coagulant for water treatment for removing fluorine which minimizes scale generation occurring when aluminum sulfate is used is required .

Registration of Korean Patent No. 0984448 2010.09.20.

In order to solve the above-mentioned problems, the present invention provides an inorganic coagulant for water treatment using aluminum sulfate as an active ingredient. It is used as an inorganic coagulant for fluorine removal for treatment of fluorine generated in industrial wastewater, corresponding to environmental regulations to minimize the chlorine ions (for example, the Chinese regulation to 500ppm or less) one against the other hand, the poly aluminum chloride that enable fluorine removal efficiency so as to obtain an excellent effect compared to Al ₂ O ₃ content of fluorine And to provide a method for producing an inorganic coagulant for water treatment.

Another object of the technology of the present invention is to provide a method for producing an inorganic coagulant which is applied to an inorganic coagulant containing aluminum sulfate as an active ingredient and an aluminum sulfate liquid as an active ingredient, Freezing (precipitation) phenomenon can be prevented, transportation and storage can be facilitated, and scale generation occurring when aluminum sulfate is used can be minimized.

The present invention for achieving the above-mentioned objects is as follows. That is, the production method of the water treatment inorganic coagulant for for fluorine removal in accordance with the present invention, in the production method of the water treatment inorganic coagulant for for fluorine removal of agglomeration process the fluorine contained in industrial waste water, the aluminum sulphate Al as the active ingredient ₂ An aluminum sulfate solution preparation step of preparing a solution prepared by dissolving in purified water so that the content of O ₃ is 6 to 8 mass%; Adding / dissolving a solution prepared by adding the Al ₂ O ₃ content of aluminum nitrate to the solution prepared through the step of preparing the aluminum sulfate solution by adding 0.1 to 2.0 mass% of aluminum nitrate; Mixing and diluting phosphoric acid in the solution dissolved through the addition / dissolution step so as to have a concentration of 0.1 to 5.0 mass%; And completing the preparation of the inorganic coagulant and so that the solution mixture through the mixing step, Al ₂ O ₃ content of 7.5 wt% 0.1 ~ Al ₂ O ₃ content through the mixing by adding to a 2.0% by weight of aluminum chloride Lt; / RTI > addition / mixing step.

Here, in the adding / dissolving step, in place of the aluminum nitrate, in the solution prepared through the aluminum sulfate solution preparing step,

Nitric acid or nitrate to a concentration of 0.5 to 5.0% by mass.

In addition, the mixing step may include a step of diluting the solution dissolved in the adding / dissolving step so that the concentration of the phosphate is 0.1 to 5.0 mass% in place of the phosphoric acid, and mixing.

In the addition / mixing step, the Al ₂ O ₃ content of the aluminum polychloride or aluminum polychloroaluminate is added to the mixed solution through the mixing step so as to be 0.1 to 2.0 mass% And the content of Al ₂ O ₃ is 7.5% by mass, thereby completing the preparation of the inorganic coagulant.

In preparing the aluminum sulfate solution, a solution prepared by dissolving aluminum sulfate silicate in purified water so that Al ₂ O ₃ content of aluminum sulfate silicate is 6 to 8 mass% is prepared in place of aluminum sulfate Process.

Further, in the adding / dissolving step, the Al ₂ O ₃ content of aluminum nitrate is added and dissolved in the solution prepared through the aluminum sulfate solution preparing step, and after the aluminum nitrate addition, at 40 to 60 degrees Followed by complete dissolution for 30 minutes.

Further, in the adding / mixing step, the Al ₂ O ₃ content of the aluminum chloride is added to the mixed solution through the mixing step so that the Al ₂ O ₃ content is 0.1 to 2.0 mass%, and the Al ₂ O ₃ content is adjusted to 7.5 mass% to, but to complete the preparation of the inorganic coagulant, it is preferred that the Al ₂ O ₃ content of the aluminum chloride is formed by the process of was added so that 0.1 to 2.0% by weight, after the step of mixing for 10 minutes to complete the preparation of the inorganic flocculant.

The effect of the method for producing an inorganic flocculant for water treatment for fluorine removal according to the present invention will be described below.

First, as an inorganic coagulant for water treatment using aluminum sulfate as an active ingredient, it is used as an inorganic coagulant for fluorine removal for fluoride treatment generated in industrial wastewater, and minimizes chlorine ion generated by treatment with poly can be obtained an excellent effect (for example in China regulated by 500ppm or less) in comparison with the other hand, the poly aluminum chloride that enable fluorine removal efficiency compared to Al ₂ O ₃ content.

Second, the application of aluminum sulfate as an effective ingredient prevents the freezing (precipitation) phenomenon that occurs during transport and storage during the winter season, unlike the conventional inorganic sulfate flocculant, which is an aluminum sulfate liquid, against an inorganic flocculant containing an aluminum sulfate liquid as an effective ingredient. Thereby facilitating transportation and storage, while minimizing scale generation occurring when aluminum sulfate is used.

Hereinafter, preferred embodiments of a method for producing an inorganic flocculant for water treatment for fluorine removal according to the present invention will be described in detail.

The method for producing an inorganic flocculant for water treatment for removing fluorine according to a preferred embodiment of the present invention is a method for producing an inorganic flocculant for water treatment for removing fluorine which flocculates fluorine contained in industrial wastewater, An addition / dissolution step, a mixing step and an addition / mixing step.

Specifically, the aluminum sulfate solution preparation step comprises preparing a solution prepared by dissolving the aluminum sulfate in purified water so that the content of Al ₂ O _{3 in the} aluminum sulfate is 6 to 8% by mass as an active ingredient.

Also, the adding / dissolving step comprises adding 0.1 to 2.0% by mass of Al ₂ O _{3 in} aluminum nitrate to the solution prepared through the aluminum sulfate solution preparing step and dissolving.

In the mixing step, the phosphoric acid is diluted to a concentration of 0.1-5.0 mass% and mixed in the solution dissolved through the addition / dissolution step.

In the addition / mixing step, the Al ₂ O ₃ content of the aluminum chloride is added to the mixed solution through the mixing step so that the Al ₂ O ₃ content becomes 0.1 to 2.0 mass%, and the Al ₂ O ₃ content becomes 7.5 mass% Thereby completing the preparation of the inorganic coagulant.

Meanwhile, in the method of manufacturing an inorganic flocculant for water treatment for removing fluorine according to the present invention, the addition / dissolution step may be performed by adding the aluminum nitrate to the solution prepared through the aluminum sulfate solution preparing step And adding the nitric acid or nitrate to the solution so that the concentration of the nitric acid or the nitrate is 0.5 to 5.0% by mass and dissolving the solution.

The mixing step may be performed by mixing the solution dissolved in the adding / dissolving step with diluted phosphoric acid so that the concentration of the phosphate is 0.1 to 5.0 mass%.

In the addition / mixing step, the Al ₂ O ₃ content of the aluminum polychloride or aluminum polychloroaluminate is added to the mixed solution through the mixing step so as to be 0.1 to 2.0 mass% And the content of Al ₂ O ₃ is 7.5% by mass, thereby completing the preparation of the inorganic coagulant.

Further, in preparing the aluminum sulfate solution, a solution prepared by dissolving aluminum sulfate silicate in purified water so that the content of Al ₂ O _{3 in} aluminum sulfate silicate is 6 to 8% by mass is prepared in place of the aluminum sulfate It can be done in process.

Example 1, which is an embodiment of an inorganic flocculant for water treatment for removing fluorine, produced by the method for producing an inorganic flocculant for water treatment for removing fluorine according to the present invention, comprising the steps as described above, (In comparison with Example 1 and Comparative Example 1), freezing (in comparison with Example 1 and Comparative Example 2), scale adhesion amount (in Example 1 And the contrast of Comparative Example 2) will be described.

As an inorganic coagulant for water treatment for removing fluorine produced by a method for producing an inorganic coagulant for water treatment for removing fluorine according to the present invention, Example 1 is a method for producing an inorganic coagulant for water treatment, which is a liquid or solid aluminum sulfate An aluminum sulfate solution preparation step of preparing a solution prepared by dissolving in purified water so that the Al ₂ O ₃ content is 7 mass%

Adding / dissolving step in which aluminum nitrate (Al ₂ O ₃ content 1 mass%) is added and completely dissolved at 40 to 60 degrees for 30 minutes,

A mixing step of adding and mixing phosphoric acid (concentration 2 mass%) to the solution dissolved through the addition / dissolution step and

(Al ₂ O ₃ content: 1% by mass) as a commercially available water treatment agent and then mixed for 10 minutes so that the content of Al ₂ O ₃ becomes 7.5% by mass to complete the preparation of the inorganic coagulant / Mixing step to prepare inorganic coagulant.

[Comparative Example 1]

Comparative Example 1 was prepared as polychlorinated aluminum (Al ₂ O ₃ content 10 mass%) as a commercially available water treatment agent.

[Comparative Example 2]

In Comparative Example 2, aluminum sulfate (Al ₂ O ₃ content: 7.5% by mass) was prepared as a commercially available water treatment agent.

First, Example 1 prepared as an inorganic flocculant (Al ₂ O ₃ content 7.5% by mass) prepared by the method for producing an inorganic flocculant for water treatment for removing fluorine according to the present invention as described above, and Example 1 prepared as a commercially available water treatment agent (Al ₂ O ₃ content: 10% by mass) was prepared in the same manner as in Comparative Example 1,

The effluent was tested for dilution of industrial wastewater (electronic wastewater) with a fluorine concentration of 20ppm, pH7, and the first experiment results were obtained.

In this experiment, 500 ml of the experimental wastewater prepared as described above was placed in a beaker having a capacity of 1 L, and then the inorganic coagulant of Example 1 and Comparative Example 1 was added. After stirring for 10 minutes at 100 rpm using a stirrer, Ph was adjusted to 7 , Stirring was continued at 30 rpm for 5 minutes, and the mixture was allowed to stand for 20 minutes. The supernatant was used as a sample to measure the fluoride ion.

Here, a 2 mass% calcium hydroxide solution was used as a Ph neutralizing agent for pH adjustment.

The results of the first experiment of the fluorine removal efficiency with respect to the amount of fluorine and the fluorine removal efficiency according to the input amounts of Example 1 and Comparative Example 1 were obtained as shown in Tables 1 to 4 below.

[First experiment result of fluorine removal efficiency]

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 500 12.4 38.0 Example 1 500 13.2 34

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 1000 9.2 54.0 Example 1 1000 10.1 49.5

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 1500 7.9 60.5 Example 1 1500 8.2 59.0

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 2000 6.2 69.0 Example 1 2000 6.4 68.0

According to the results of the first experiment of fluorine removal efficiency as described above, the fluorine removal efficiency of Example 1 is slightly less than 5% as compared with Comparative Example 1. In other words, the fluorine removal efficiency of Example 1 Was comparable.

As another experimental example of the fluorine removal efficiency, the industrial wastewater (electronic wastewater) to be used in the experiment was diluted with a fluorine concentration of 5 ppm Ph7 and prepared. The experimental method was the same as in the first experiment of fluorine removal efficiency And the results of the second fluorine removal efficiency test were obtained.

The results of the second experiment on the fluorine removal efficiency and the fluorine removal efficiency according to the input amounts of Example 1 and Comparative Example 1 were derived as shown in Tables 5 to 7 below.

[Second experiment result of fluorine removal efficiency]

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 500 2.2 56 Example 1 500 2.4 52

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 800 0.4 92 Example 1 800 0.5 90

Input (ppm) Fluorine residual amount (ppm) Fluorine Removal Efficiency (%) Comparative Example 1 1000 0.2 96 Example 1 1000 0.3 94

According to the results of the second experiment of fluorine removal efficiency as described above, the fluorine removal efficiency of Example 1 is slightly different from 4% or 2% as compared with Comparative Example 1, Removal efficiencies were comparable.

On the other hand, Example 1 prepared by an inorganic flocculant (Al ₂ O ₃ content: 7.5% by mass) prepared by a method for producing an inorganic flocculant for water treatment for removing fluorine according to the present invention and aluminum sulfate (Al ₂ O ₃ content: 7.5% by mass) was prepared,

The freezing test was performed based on a number of temperature conditions. The results of the freezing test are shown in Table 8 below.

[Freezing test result]

Temperature -10 degrees -15 degrees -20 degrees Comparative Example 2 solution frost frost Example 1 solution solution solution

According to the results of the freezing test as described above, in Comparative Example 1, freezing occurred at a temperature of -15 degrees and -20 degrees, whereas in Example 1, freezing occurred even at a temperature of -15 degrees and -20 degrees, And maintained in the solution state.

On the other hand, Example 1, which was prepared by an inorganic flocculant (Al ₂ O ₃ content 7.5% by mass) prepared by the method for producing an inorganic flocculant for water treatment for fluorine removal according to the present invention as described above, with respect to the Comparative example 2, prepared in a (Al ₂ O ₃ content of 7.5% by weight),

The test was carried out under the conditions of sample (15mm × 30mm, SUS), self-tester (Jar tester) {test bath (500ml), 30rpm} , And then dried at 105 ° C for 2 hours to measure the scale adhesion amount.

In the scale adhesion test as described above, the specimen weight and scale adhesion amount were measured for the specimens of Example 1 and Comparative Example 2 at the initial stage, 5 hours and 15 hours later. The results of the scale adhesion test were as shown in Table 9 below .

[Scale adhesion amount test result]

Psalter
Initial Weight After 5 hours
Specimen weight scale
Adhesion After 15 hours
Specimen weight scale
Adhesion result Comparative Example 2 15.7816gr 15.7857gr 0.0041gr 15.8239gr 0.0423 gr usually Example 1 15.9282 gr 15.9314gr 0.0032gr 15.9420gr 0.0138gr Good

According to the results of the above-mentioned scale adhesion amount test, the scale adhesion amount of Example 1 was compared with the scale adhesion amount according to the weight of the specimen after 5 hours as compared with the Comparative Example 2, .

In other words, the results of the scale adhesion test as described above show that the scale adhesion amount of Example 1 is much smaller than that of Comparative Example 2.

According to the method for producing an inorganic flocculant for water treatment for removing fluorine according to the present invention as described above, as an inorganic flocculant for water treatment applying aluminum sulfate as an effective ingredient, an inorganic flocculant for fluorine removal It is possible to minimize the chlorine ion generated by the treatment with polychlorinated aluminum when used, and to cope with the environmental regulations (for example, in the case of China, it is regulated to be 500 ppm or less), while the fluorine removal efficiency is also improved by Al ₂ O ₃ It is possible to obtain a superior effect on the content.

Furthermore, unlike inorganic coagulants used for water treatment, which are conventional aluminum sulfate liquids, anti-freezing (precipitation) phenomena occurring during transportation and storage during the winter season are prevented from being applied to inorganic coagulants containing aluminum sulfate as an effective component, Thereby facilitating transportation and storage, and minimizing scale generation occurring when aluminum sulfate is used.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited thereto. Various modifications may be made by those skilled in the art. Are included in the scope of the present invention.

Claims (7)

A method of producing an inorganic flocculant for water treatment for removing fluorine, which flocculates fluorine contained in industrial wastewater,
An aluminum sulfate solution preparation step of preparing a solution prepared by dissolving Al ₂ O _{3 in an} amount of 6 to 8% by mass as an active ingredient in purified water;
Adding / dissolving a solution prepared by adding the Al ₂ O ₃ content of aluminum nitrate to the solution prepared through the step of preparing the aluminum sulfate solution by adding 0.1 to 2.0 mass% of aluminum nitrate;
Mixing and diluting phosphoric acid in the solution dissolved through the addition / dissolution step so as to have a concentration of 0.1 to 5.0 mass%; And
The Al ₂ O ₃ content of aluminum chloride is added to the mixed solution so that the Al ₂ O ₃ content is 0.1 to 2.0% by mass, and the Al ₂ O ₃ content is adjusted to 7.5% by mass through mixing to complete the preparation of the inorganic coagulant A method for producing an inorganic flocculant for water treatment for fluorine removal comprising an addition / mixing step.
The method according to claim 1,
Wherein the adding / dissolving step is a step of adding, to the solution prepared through the aluminum sulfate solution preparing step,
Nitric acid or nitrate in an amount of 0.5 to 5.0% by weight based on the total weight of the inorganic coagulant.
The method according to claim 1,
Wherein the mixing step comprises adding, to the solution dissolved through the addition / dissolution step,
Wherein the concentration of the phosphate is in the range of 0.1 to 5.0% by mass and mixed.
The method according to claim 1,
Wherein the adding / mixing step comprises adding, to the mixed solution through the mixing step,
The Al ₂ O ₃ content is 0.1 ~ Al ₂ O ₃ content through the mixing by adding to a 2.0% by weight of poly aluminum or polychlorinated aluminum silicate chloride is such that 7.5% by mass of the made of a process for completing the preparation of the inorganic coagulant Wherein the inorganic flocculant is water-soluble.
The method according to claim 1,
In the preparation of the aluminum sulfate solution, aluminum sulfate is applied instead of the aluminum sulfate,
And preparing a solution prepared by dissolving Al ₂ O _{3 in an} amount of 6 to 8% by mass in aluminum sulfate.
The method according to claim 1,
In the adding / dissolving step, 0.1-2.0% by mass of Al ₂ O ₃ is added to the solution prepared through the aluminum sulfate solution preparation step,
And then completely dissolving the aluminum nitrate solution at 40 to 60 degrees for 30 minutes. The method for producing an inorganic flocculant for water treatment for removing fluorine according to claim 1,
The method according to claim 1,
In the adding / mixing step, the Al ₂ O ₃ content of the aluminum chloride is added to the mixed solution through the mixing step so that the Al ₂ O ₃ content becomes 0.1 to 2.0 mass%, and the Al ₂ O ₃ content is adjusted to 7.5 mass% Complete the preparation of the coagulant,
Adding Al ₂ O _{3 to} aluminum chloride in an amount of 0.1 to 2.0% by mass, and then mixing the mixture for 10 minutes to complete the preparation of the inorganic coagulant. Gt;