KR20230065004A - Arsenic adsorbent manufacturing apparatus and arsenic adsorbent manufacturing method using same - Google Patents

Abstract

The present invention relates to an apparatus for manufacturing an arsenic adsorbent, which is a layered double hydroxide that acts as an arsenic stabilizer to absorb arsenic contained in soil or water and mitigate the harmfulness of arsenic, and a method for manufacturing an arsenic adsorbent using the same. a mixing unit for adjusting the pH of a mixture of silver, water, a magnesium compound, and an iron compound; a drying unit for drying the mixture discharged from the mixing unit; a transfer unit for storing the dried mixture in the drying unit and automatically transporting it to the next process; a pulverizing unit for pulverizing with a stirrer together with the mixture transferred through the transfer unit by injecting washing water; a dissolution dilution unit for dissolving and diluting the salt by allowing the mixture disintegrated in the disintegration unit to flow along the path; a control unit for uniformly maintaining the concentration of the mixture transported along the path from the dissolving and diluting unit; a discharge unit for separating washing water included in the mixture through a pressure difference with respect to the uniform concentration of the mixture transferred along the path from the control unit; and a decontamination unit configured to remove the salt of the washing water separated from the discharge unit through ion exchange and to recycle the decontaminated washing water as water supply.

Description

Arsenic adsorbent manufacturing apparatus and arsenic adsorbent manufacturing method using the same {Arsenic adsorbent manufacturing apparatus and arsenic adsorbent manufacturing method using same}

The present invention relates to an apparatus for manufacturing an arsenic adsorbent and a method for manufacturing an arsenic adsorbent using the same. It relates to an apparatus for manufacturing an adsorbent and a method for manufacturing an arsenic adsorbent using the same.

Arsenic is currently one of the environmental toxicants of greatest concern worldwide. Groundwater contaminated with high concentrations of arsenic has been reported in countries around the world, including the United States and Southeast Asia, including India, Bangladesh, Thailand, and Vietnam. there is.

Arsenic is widely distributed in the earth's crust, and is mainly present in iron-containing ores, sulfides of igneous origin, or marine shale in the form of ferrous iron (FeAsS), silicium (AsS), or turmeric (As ₂ S ₃ ).

Arsenic is mainly introduced into the environment by the dissolution of these naturally occurring arsenic minerals, but recently, the inflow due to various artificial causes (mining activity, smelting activity, sulfuric acid production process or pesticide spraying, etc.) is about 4 times the natural inflow amount. The situation is up to.

Arsenic exists in nature in the form of arsenate (As(V)), arsenite (As(III)), arsenicmetal (AsO), or arsine (As(-III)) depending on its oxidation state, but among these, AsO naturally exists. Since the amount is very small and As(-III) exists only in highly reducing environments electrochemically, the focus of arsenic behavior in a relatively general natural environment is on As(V) and As(III).

It is the above-mentioned oxidation state of arsenic that plays an important role in the geochemical behavior of arsenic in a soil or groundwater environment.

In the natural world, arsenic mainly exists in oxidation states of +3 and +5, but unlike most heavy metal elements that have a positive charge in a dissolved state, arsenic appears in an oxyanion or uncharged state.

That is, As(V)(arsenate) with +5 valency exists in the form of H ₂ AsO ₄ ^- and HAsO ₄ ^2- , and As(Ⅲ) (arsenite) with +3 valence exists in the form of H ₃ AsO ₃ and H ₂ AsO ^3- do.

The toxicity of arsenic depends on its oxidation state and its organic/inorganic form. In this case, the reduced/inorganic form is generally more toxic than the oxidized/organic form. It is adsorbed or co-precipitated on particles or colloids of manganese oxides, aluminum oxides, mainly iron oxides and has low solubility and mobility, whereas reduced As(III) has high solubility and mobility and is 20 to 60 times more toxic. It is known.

Arsenic exhibits different migration characteristics from other heavy metals and metalloids in typical groundwater pH and redox potential environments.

That is, most of the toxic heavy metal elements that exist as cations in an aqueous solution state increase in solubility as the pH decreases, whereas at neutral and alkaline pH, metal oxides coprecipitated with oxides, hydroxides, carbonates, or phosphate minerals, or hydrated metal oxides, Solubility is reduced due to strong adsorption to clay or organic substances.

On the other hand, most of the elements forming oxidative anions, including arsenic, show a characteristic that their content in the aqueous system increases as their adsorption capacity decreases as the pH increases.

In addition, arsenic is distinguished from other oxide anions in geochemical characteristics. That is, while other oxide anions have low mobility in a reduced state, arsenic has a relatively low mobility in an oxidized state, such as being easily adsorbed to nearby iron oxides. show

Currently applied technologies for arsenic removal from soil or groundwater are mainly focused on arsenic removal from groundwater.

Academic research on arsenic-contaminated soil is insignificant, and restoration technologies for arsenic-contaminated soil are galvanic remediation technology, vitrification technology, soil washing/acid extraction method, heat treatment metal recovery technology, soil cleaning technology, solidification/stabilization Technology or plant restoration technology is presented.

In Korea, a soil stabilization method that reduces the toxicity, solubility, or mobility of arsenic by adding a stabilizer such as an adsorbent or precipitator to arsenic-contaminated soil is widely applied, and lime or steelmaking slag is mainly used as a stabilizer. .

In the case of lime or steelmaking slag, when injected into arsenic-contaminated soil, the calcium component in the stabilizer reacts with arsenic to form an insoluble precipitate to stabilize it, but there is a risk of increasing the pH of the soil and increasing the dissolution of arsenic.

Accordingly, there is an urgent need to develop a stabilizer capable of effectively reducing the harmfulness of arsenic and remarkably reducing the occurrence of secondary contamination, and the development of a device for rapidly and efficiently producing such a stabilizer is urgently needed. .

In order to meet the needs of this development, Patent Document 1 previously filed by the present applicant includes (a) preparing an arsenic adsorbent by mixing a magnesium compound solution and an iron compound solution; (b) adding the arsenic adsorbent prepared in step (a) to water containing pentavalent arsenic; and (c) after step (b), the arsenic adsorbent in step (a) is added to the water containing pentavalent arsenic in step (b) and shaken for 23 to 25 hours; The magnesium compound is MgSO ₄ 7H ₂ O, the iron compound is Fe ₂ (SO ₄ ) ₃ 5H ₂ O, and the magnesium compound is 240 to 250 parts by weight with respect to 100 parts by weight of the iron compound, the above (b With respect to 100 parts by weight of the arsenic adsorbent introduced in step), a method for manufacturing an arsenic adsorbent having 1 to 6 parts by weight of arsenic pentavalent, an arsenic adsorbent produced by the manufacturing method, and an arsenic removal method using the arsenic adsorbent are posted, and such Through Patent Document 1, it was possible to manufacture LDH by improving conventional LDH (layered double hydroxide) and remove a large amount of arsenic more effectively than LDH according to the prior art.

However, despite the structural improvement as described above, the manufacturing scale of LDH is small, and a systematic and efficient manufacturing method is not presented, so various limitations remain for application to contaminated sites. The situation is.

Republic of Korea Patent Registration No. 10-1890910 (2018.08.22. Notice)

An object of the present invention is to provide an apparatus for manufacturing an arsenic adsorbent, which is a layered double hydroxide that acts as an arsenic stabilizer to absorb arsenic contained in soil or water to mitigate the harmfulness of arsenic, and a method for manufacturing an arsenic adsorbent using the same.

At the same time, the present invention also provides an arsenic adsorbent manufacturing device capable of systematically and efficiently producing a large amount of LDH in relation to the manufacturing method of LDH (layered double hydroxide) according to the prior art mentioned above and a method for manufacturing an arsenic adsorbent using the same. It will be said to belong to the purpose of the invention.

An arsenic adsorbent manufacturing apparatus according to the present invention for achieving the above object includes a mixing unit for adjusting the pH of a mixture of water, a magnesium compound and an iron compound; a drying unit for drying the mixture discharged from the mixing unit; a transfer unit for storing the dried mixture in the drying unit and automatically transporting it to the next process; a pulverizing unit for pulverizing with a stirrer together with the mixture transferred through the transfer unit by injecting washing water; a dissolution dilution unit for dissolving and diluting the salt by allowing the mixture disintegrated in the disintegration unit to flow along the path; a control unit for uniformly maintaining the concentration of the mixture transported along the path from the dissolving and diluting unit; a discharge unit for separating washing water included in the mixture through a pressure difference with respect to the uniform concentration of the mixture transferred along the path from the control unit; and a decontamination unit configured to remove the salt of the washing water separated from the discharge unit through ion exchange and to recycle the decontaminated washing water as water supply.

In the mixing unit, 400 L of water, 150 to 250 kg of an aqueous ferric sulfate solution, and 240 to 300 kg of magnesium sulfate are put into a blender, stirred at a speed of 50 to 60 RPM for 1 hour, and then 100 to 150 kg of sodium hydroxide is added to the blender, After stirring for 2 hours at a speed of 50 to 60 RPM, the stirring is stopped to measure the pH. When the pH is measured in the range of 9 to 11, the mixture may be transferred to the drying unit through the discharge port of the blender.

The control unit allows the mixture diluted in the dissolution dilution unit to flow into the buffer tank so that the conductivity is diluted and stirred at a speed of 100 to 200 RPM through a stirrer so that the conductivity is 10 mS / cm or less using a conductivity meter, and the conductivity value is 10 mS / When it exceeds cm, the conductivity value may be adjusted to 10 mS/cm or less by adjusting the amount of the mixture disintegrated in the disintegration unit or the amount of water supplied from the water supply tank.

The discharge unit may separate the mixture transported from the control unit into LDH (Layered Double Hydroxide) and salt wastewater through a filter press, and then transport them to the drying unit.

The salty wastewater separated through the discharge unit flows into the wastewater storage tank along a path, and the salty wastewater flowing from the wastewater storage tank to the decontamination unit is decontaminated through an ion exchange resin and stored in a water supply tank.

An arsenic adsorbent manufacturing method using the arsenic adsorbent manufacturing apparatus described above, comprising: a first step of mixing water, a magnesium compound, and an iron compound; A second step of maintaining the pH of the mixture of the first step at 9 to 11; A third step of drying the mixture at a temperature of 100 to 150 ° C. for 12 to 24 hours; A fourth step of disintegrating (pulverizing) and decontaminating the LDH (Layered Double Hydroxide) generated through the third step; and a fifth step of dehydrating and drying the LDH that has passed through the fourth step.

According to the configuration of the present invention described above, an apparatus for manufacturing an arsenic adsorbent, which is a layered double hydroxide that acts as an arsenic stabilizer to adsorb arsenic contained in soil or water to mitigate the harmfulness of arsenic, and a method for manufacturing an arsenic adsorbent using the same There are effects that can be done.

At the same time, there is also an effect of systematically producing a large amount of LDH with respect to the method for producing LDH (layered double hydroxide) according to the prior art mentioned above.

Furthermore, the effect of preventing water pollution by recycling wastewater can be expected, and since the arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same are made in an automated process, there is an effect of increasing efficiency and securing economic feasibility.

1 is a diagram schematically shown to explain detailed processes of an apparatus for manufacturing an arsenic adsorbent and a method for manufacturing an arsenic adsorbent using the same according to the present invention.
Figure 2 shows the results of SEM-EDS analysis of P-LDH for the experimental example of the present invention.
3 is a photograph showing the process of Experimental Example 4 among the experimental examples of the present invention.

Hereinafter, with reference to the accompanying drawings, preferred implementation configurations for realizing the object of the present invention described above and operational relationships according to these configurations will be described, and detailed descriptions of technical configurations in the same or the same category as the prior art will be omitted. do it with

The present invention relates to an apparatus for manufacturing an arsenic adsorbent, which is a layered double hydroxide that acts as an arsenic stabilizer to absorb arsenic contained in soil or water to mitigate the harmfulness of arsenic, and a method for manufacturing an arsenic adsorbent using the same.

The configuration of the arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same according to the present invention includes a first step of mixing water, a magnesium compound and an iron compound, and a second step of maintaining the pH of the mixture in the first step at 9 to 11. step, the third step of drying the above-described mixture at a temperature of 100 to 150 ° C. for 12 to 24 hours, and pulverization (pulverization) and decontamination of LDH (Layered Double Hydroxide) generated through the third step It may include a fourth step of dehydration and a fifth step of dehydrating and drying the LDH that has passed through the fourth step.

The arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same of the present invention in order to embody this will be described in detail through the following examples.

First, as an arsenic adsorbent manufacturing apparatus according to an arsenic adsorbent manufacturing method, as shown in FIG. 1, a mixing unit 10 for mixing water, a magnesium compound and an iron compound and adjusting the pH of the mixture, and the mixing unit ( A drying unit 20 for drying the mixture discharged in 10), a transfer unit 30 for storing the dried mixture in the drying unit 20 and automatically transferring it to the next process, and a transfer unit 30 for injecting washing water A disintegration unit (40) for disintegrating the mixture transferred through the agitator (A) together with a disintegration unit (50) for dissolving and diluting the salt by allowing the mixture disintegrated in the disintegration unit (40) to flow along the path ), a control unit 60 that uniformly maintains the concentration of the mixture transferred along the path in the dissolution and dilution unit 50, and a pressure for the mixture of uniform concentration transferred along the path in the control unit 60 A discharge unit 70 that separates the washing water included in the mixture through tea, and a decontamination unit 80 that removes the salt of the washing water separated from the discharge unit 70 through ion exchange and recycles the decontaminated washing water as water supply. ).

Here, in the mixing unit 10 of the present invention, 400 L of water, 200 kg of ferric sulfate aqueous solution, and 260 kg of magnesium sulfate are added to the blender 11 and stirred for 1 hour at a speed of 50 to 60 RPM, and then the blender (11 ) was added with 130 kg of sodium hydroxide, stirred at a speed of 50 to 60 RPM for 2 hours, and then stopped stirring to measure the pH. The mixture is transferred to the drying unit 20.

For example, the above mixture may be transferred to a drying tray and transferred to the drying unit 20, and the blended mixture may be dried at a temperature of 150° C. for 12 hours in the drying unit 20.

Then, the dried mixture can be transferred to the hopper 31 of the transfer unit 30 and transferred to the disintegration unit 40, which is the next process, through the screw feeder 32.

In addition, the crushing unit 40 of the present invention may be formed in the shape of a conventional water tank, and well release the transferred mixture and the water supplied from the water supply tank 90 at a speed of 200 to 300 RPM through the stirrer (A) can be made to break up.

In addition, the dissolving and diluting unit 50 of the present invention may also be made in a shape similar to that of a conventional water tank, and when the disintegrated mixture is automatically transported and introduced into the inside, the water supplied from the water supply tank 90 and the stirrer (A) It can be diluted and stirred at a speed of 200 to 300 RPM through.

In addition, the control unit 60 of the present invention allows the mixture diluted in the dissolution and dilution unit 50 to automatically flow into the buffer tank 61 (water tank shape) along the path so that the conductivity is measured using a conductivity meter (EC-meter). Dilute and stir at a speed of 100 to 200 RPM through an agitator (A) so that is less than 10 mS / cm, and when the conductivity value exceeds 10 mS / cm, the amount of the mixture disintegrated in the above-mentioned disintegration unit 40 or water tank It functions so that the conductivity value is adjusted to 10 mS/cm or less by adjusting the amount of water supplied in (90).

In addition, the discharge unit 70 of the present invention separates the mixture automatically transported along the path from the above-described control unit 60 into the above-described LDH and salt wastewater through a filter press, and then to the drying unit 20 can be transported.

At this time, the above-described LDH is separated in the same form as a solid material. The automatic transfer of the mixture to the discharge unit 70 is continuously maintained, but the LDH is filled in the discharge unit 70 by the continuous automatic transfer of the mixture. The transfer of the mixture can be maintained until the operation of 70 is stopped, and the separated and dehydrated LDH in a solid state is transferred to a drying tray and dried in the drying unit 20 at a temperature of 150 ° C. for 12 hours. there is.

In this way, when the drying of the LDH transported in a solid state is completed, the preparation of the arsenic adsorbent according to the present invention can be completed.

On the other hand, the salt wastewater separated through the above-described discharge unit 70 may automatically flow into the wastewater storage tank 71 along the path, and at this time, the conductivity value of the salt wastewater introduced from the wastewater storage tank 71 is controlled by the above-mentioned control. It is preferable that the wastewater storage tank 71 is also equipped with a conductivity meter to measure whether the conductivity of the mixture in the unit 60 is similar to that of the mixture.

In addition, the salt wastewater stored in the wastewater storage tank 71 automatically flows into the decontamination unit 80 along the path, and the introduced salt wastewater is decontaminated through the ion exchange resin and stored in the water supply tank 90, thereby Water circulation can be achieved in the process of the arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same.

In addition, in the arsenic adsorbent manufacturing apparatus and arsenic adsorbent manufacturing method using the same of the present invention, a control unit (C) is provided to automatically move the mixture or water in detailed processes, a pump, a water level sensor or an agitator (A) of each component They can be manually or automatically adjusted.

According to the present invention configured as described above, it is possible to provide an apparatus for manufacturing an arsenic adsorbent, which is a layered double hydroxide that acts as an arsenic stabilizer to adsorb arsenic contained in soil or water to mitigate the harmfulness of arsenic, and a method for manufacturing an arsenic adsorbent using the same. It can.

In addition, it is possible to systematically produce a large amount of LDH with respect to the manufacturing method of LDH (layered double hydroxide) according to the prior art, and the effect of preventing water pollution by recycling wastewater can be expected, and an arsenic adsorbent manufacturing device and As the arsenic adsorbent manufacturing method using this is made in an automated process, it is possible to increase efficiency and secure economic feasibility.

Hereinafter, experimental examples in which the degree of stabilization was measured by applying the arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same according to the present invention to arsenic-contaminated soil will be described.

In addition, using LDH according to an embodiment of the present invention, but using powdery LDH (P-LDH) and granular LDH (B-LDH) as a stabilizer for arsenic-contaminated soil, to investigate the arsenic removal effect of LDH make it clear

Here, since the application of P-LDH by covering the surface contaminated soil can cause pollution due to the generation of dust, in order to compensate for this disadvantage, B-LDH form was prepared to prove the efficiency of application to contaminated soil want to do

In the experimental examples of the present invention, tailings-contaminated soil collected from Cheonan-si, Chungcheongnam-do was dried by oven drying at 40 ° C, sieved with 100 mesh, and then subjected to full content extraction to ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) for heavy metals. Concentrations were analyzed.

As a result of total content analysis, the concentrations of arsenic, copper, lead, and zinc in the collected soil were 112.52, 40.65, 74.45, and 26.02 mg/kg, respectively, and it was confirmed that arsenic exceeded the soil contamination countermeasure standard value.

On the other hand, to prepare B-LDH, a B-LDH stabilizer (arsenic adsorbent) having a size of 5 to 6 mm was prepared using starch (35 wt%) as a binder, and the physicochemical properties of P-LDH and B-LDH were investigated. For comparison, SEM-EDS (Scanning Electron Microscopy-Energy Dispersive Spectroscopy), BET (Brunauer Emmett Teller), and XRD/XRF analysis were performed.

As a result of BET analysis, it was found to be 28.65 m 2 / g, and as shown in FIG. 2, as a result of SEM analysis, it was confirmed that the surface of LDH appeared in the form of a layered structure, and through EDS results, it was confirmed that LDH with a high Mg-Fe content .

Through this, it is possible to predict that exchangeable anions between layers will be adsorbed through ion exchange with arsenic.

[Experimental Example 1: Arsenic Adsorption Batch Experiment of P-LDH]

First, 10 mg/L of arsenic-contaminated water was prepared, and the eluate (arsenic-artificially contaminated water) was mixed with 1.5 g of P-LDH at a ratio of 1:20, and the supernatant was extracted and filtered by time (2, 12, 24 hours). was carried out, and the solution extracted over time was analyzed for arsenic concentration using the above-described ICP-OES, and the reduction efficiency was calculated using the following formula.

Calculation formula: Reduction efficiency (%) = ( _{CO -CS} ) / C ₀ × 100

( _CO : concentration of sample without stabilizer added, C _S : concentration of sample with stabilizer added)

In order to investigate the arsenic removal efficiency of LDH, an adsorption batch experiment of P-LDH was conducted. The possibility of arsenic adsorption was confirmed.

[Table 1]

[Experimental Example 2: Arsenic Elution Reduction Test of B-LDH]

Completely dried tailings-contaminated soil was sieved with 10 mesh, B-LDH was mixed with soil by addition amount (0, 5, 7, 10%), and distilled water appropriated to pH 6±0.5 using hydrogen chloride was used as the eluent. , The ratio of the eluate and the sample was mixed at 3:1 (90g:30g).

Then, after elution at 150 rpm for 2 hours, the supernatant of the eluate left standing for 24 hours was collected and filtered, and the concentration was analyzed using the above-described ICP-OES and shown in Table 2 below.

[Table 2]

In order to evaluate the arsenic reduction efficiency in soil, a B-LDH elution reduction experiment was conducted, and as a result, it was confirmed that the reduction efficiency increased as the amount of the stabilizer increased.

[Experimental Example 3: Soil culture experiment of B-LDH]

Completely dried tailings contaminated soil was sieved with 10 mesh, and prepared by mixing 300 g of soil sample, 30% (90 g) of moisture, and 5% of B-LDH (stabilizer ratio excluding binder is about 3%), and soil sample and 30% of water were mixed at the same ratio as the above-mentioned ratio and 7% of B-LDH (the ratio of the stabilizer excluding the binder was about 5%).

Soil culture was carried out for a total of 4 weeks under dark conditions at room temperature. About 7 g of the sample was dried in the pot for a total of 3 times, every 1 week for the first 2 weeks and once every 2 weeks thereafter, and then 5 g of the dried sample was collected. did

After extraction using the Mehlich-III extraction method for arsenic for each port, the filtrate was analyzed by the above-described ICP-OES, and the reduction efficiency (%) was calculated by comparing the heavy metal elution concentration of the control port and the heavy metal elution concentration of the stabilizer input port. Comparison by sampling time is shown in Table 3 below.

[Table 3]

As time passed, it was found that the reduction efficiency increased in both samples, and the sample with a higher stabilizer ratio showed higher reduction efficiency at the beginning, but it was confirmed that the difference was minute.

[Experimental Example 4: Column Experiment]

Completely dried tailings-contaminated soil was sieved with 10 mesh, and each column (diameter 5 cm, length 30 cm) contained 5 wt% of soil and P-LDH (stabilizer ratio excluding binder), and 5 wt% soil and B-LDH (excluding binder). Stabilizer ratio) were prepared, and only soil was filled in the column as a control.

The top and bottom of the column were filled with glass beads, and a peristaltic pump was connected and injected from the bottom of the column upstream at a rate of 0.2 ml/min. Concentrations were analyzed and shown in Table 4 below.

[Table 4]

It was confirmed that the arsenic elution concentration decreased over time, and when comparing the two samples, both stabilizers showed a sustained stabilization effect, and P-LDH had a better stabilization degree than B-LDH, but a large difference was confirmed not to be visible.

As a result, it was confirmed that the arsenic adsorbent (LDH) of the arsenic adsorbent manufacturing apparatus and the arsenic adsorbent manufacturing method using the same had an excellent adsorption capacity for arsenic despite a small specific surface area of 28.65 m 2 /g.

In the case of P-LDH, the reduction efficiency was high even at a high concentration of arsenic of 10 mg/L.

B-LDH also showed a high reduction efficiency, indicating that LDH has a layered structure and anions present inside the layer are adsorbed through ion exchange with arsenic.

In addition, when the results of the adsorption/elution reduction batch experiment and the column experiment were compared, it was found that P-LDH was relatively more efficient, which is believed to be due to the larger surface area of the powder, but P-LDH and B Both -LDH samples showed excellent stabilization persistence according to the test time, and since the difference was not large, the effect of preventing secondary pollution can be expected when B-LDH is applied to the superficially contaminated soil.

The above embodiment in the present invention is an example, and the present invention is not limited thereto. Anything having substantially the same configuration as the technical concept described in the claims of the present invention and achieving the same operational effect is included in the technical scope of the present invention.

10: mixing unit 11: blender
11a: discharge port 20: drying unit
30: transfer unit 31: hopper
32: screw feeder 40: disintegration unit
50: dissolution dilution unit 60: control unit
61: buffer tank 70: discharge unit
71: wastewater storage tank 80: decontamination unit
90: water tank A: agitator
C: control unit

Claims (6)

A mixing unit for adjusting the pH of a mixture of water, magnesium compound and iron compound;
a drying unit for drying the mixture discharged from the mixing unit;
a transfer unit for storing the dried mixture in the drying unit and automatically transporting it to the next process;
a pulverizing unit for pulverizing with a stirrer together with the mixture transferred through the transfer unit by injecting washing water;
a dissolution dilution unit for dissolving and diluting the salt by allowing the mixture disintegrated in the disintegration unit to flow along the path;
a control unit for uniformly maintaining the concentration of the mixture transported along the path from the dissolving and diluting unit;
a discharge unit for separating washing water included in the mixture through a pressure difference with respect to the uniform concentration of the mixture transferred along the path from the control unit; and
An arsenic adsorbent manufacturing apparatus comprising a; decontamination unit for removing the salt of the washing water separated from the discharge unit through ion exchange and recycling the decontaminated washing water as water supply.
According to claim 1,
The mixing part,
400L of water, 150 to 250kg of ferric sulfate aqueous solution, and 240 to 300kg of magnesium sulfate were put into a blender and stirred at a speed of 50 to 60RPM for 1 hour, then 100 to 150kg of sodium hydroxide was added to the blender and 50 to 60RPM of sodium hydroxide was added to the blender. After stirring for 2 hours at a speed, the stirring is stopped to measure the pH, and when the pH is measured in the range of 9 to 11, the mixture is transferred to the drying unit through the discharge port of the blender.
According to claim 1,
The controller,
The mixture diluted in the dissolution dilution unit is introduced into the buffer tank and diluted and stirred at a speed of 100 to 200 RPM through a stirrer so that the conductivity is 10 mS / cm or less using a conductivity meter, and the conductivity value exceeds 10 mS / cm In this case, the arsenic adsorbent manufacturing apparatus characterized in that the conductivity value is adjusted to 10 mS / cm or less by adjusting the amount of the mixture disintegrated in the disintegration unit or the amount of water supplied from the water supply tank.
According to claim 1,
The discharge part,
Arsenic adsorbent manufacturing apparatus, characterized in that the mixture transferred from the control unit is separated into LDH (Layered Double Hydroxide) and salt wastewater through a filter press and then transferred to the drying unit.
According to claim 4,
The salt wastewater separated through the discharge unit flows into the wastewater storage tank along the path, and the salt wastewater flowing from the wastewater storage tank to the decontamination unit is decontaminated through an ion exchange resin and stored in a water supply tank. Arsenic adsorbent manufacturing apparatus.
A first step of mixing water, a magnesium compound and an iron compound;
A second step of maintaining the pH of the mixture of the first step at 9 to 11;
A third step of drying the mixture at a temperature of 100 to 150 ° C. for 12 to 24 hours;
A fourth step of disintegrating (pulverizing) and decontaminating LDH (Layered Double Hydroxide) generated through the third step; and
A method for producing an arsenic adsorbent comprising a fifth step of dehydrating and drying the LDH that has passed through the fourth step.

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