KR101772520B1 - Polyaluminium chloride coagulants having neutral basicity and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a neutral basic poly-aluminum chloride (PAC)-based polymer coagulant, and to a preparation method thereof, and more particularly, to the neutral basic PAC-based polymer coagulant, which is manufactured through a series of processes consisting of mixing, reaction, cooling, diluting, filtering, and the like with aluminum hydroxide and strong hydrochloric acid as raw materials, thereby having excellent physical properties such as aluminum oxide content, pH, basicity, specific gravity, turbidity, and the like, and being excellent in coagulation efficiency, storage stability, capability of removing organic matters or phosphorus, and the like; and to the preparation method thereof.

Description

Technical Field [0001] The present invention relates to a polymeric coagulant (PAC) and a method for producing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a neutral basic aluminum chloride polymer flocculant and a method for producing the same. More particularly, the present invention relates to a process for producing a heavy hydrogen chloride-based polymer flocculant by a series of processes comprising mixing, reaction, cooling, dilution and filtration using aluminum hydroxide and concentrated hydrochloric acid as raw materials Which is excellent in physical properties such as aluminum oxide content, pH, basicity, specific gravity and turbidity, and has excellent flocculation efficiency, storage stability, organic matter and phosphorus removal ability, and a method for producing the same.

In general, chemicals such as coagulants and flocculants are added to remove fine clay, organics, bacteria, algae, colloidal materials that are not removed by conventional precipitation treatment in raw water treatment To remove colloidal components. These coagulation processes are one of the most important processes in the treatment of water and wastewater, and inorganic coagulants such as aluminum (aluminum sulfate) and iron salts (ferrous sulfate, ferric chloride) have been used for a long time.

Until now, such low molecular weight inorganic flocculants have a merit that they are relatively inexpensive. However, they are disadvantageous in that they have insufficient ability to remove turbidity and suspended substances due to a small molecular particle size in an aqueous solution and a large decrease in pH of the treated water. Aluminum sulphate, which is widely used in Korea, is inexpensive and does not cause corrosive damage compared to iron salt based coagulant. Therefore, the amount of aluminum sulfate used varies depending on the water quality of raw water. When turbidity is temporarily increased in high season such as rainy season, The processing ability is remarkably deteriorated, and the increase of residual aluminum caused by overuse of the aluminum has serious problems such as causing Alzheimer's disease.

In recent years, poly (aluminum chloride) (PAC) has been developed to replace the above-mentioned low molecular weight inorganic flocculant to improve the above disadvantages. The polychlorinated aluminum is a polybasic inorganic flocculant, and since it is a coordination substance having an aqua complex ion in an aqueous solution, -OH) crosslinks to form a polynuclear complex and the nucleus is increased to form a macerated inorganic polymer compound. In addition, aluminum polychloride has a higher rate of floc formation and sedimentation rate than aluminum sulfate, requires almost no alkaline preparation and coagulation aid, has a small amount of pH, . It has an excellent turbidity improving effect of 1.2 to 5 times with respect to both low turbidity and high turbidity, and has an advantage of good flocculation effect even at low temperature.

Such polychlorinated aluminum is generally used by mixing and reacting 2 moles of aluminum hydroxide (Al (OH) 3) with hydrochloric acid and then diluting with water.

2Al (OH) 3 + 3HCl [Al2 (OH) 3Cl3] n + 3H2O

However, the basicity of poly (aluminum chloride) is an important characteristic closely related to composition, structure, physicochemical properties, coagulation effect, storage stability, etc., and the equivalence of aluminum (Al) -OH) equivalents.

In addition to the basicity, the polychlorinated aluminum flocculant has various properties to be equipped such as flocculation efficiency, storage stability, sludge and residual aluminum generation, algae and organic removal efficiency, and phosphorus removal efficiency. There is a growing demand for an efficient and simple method for producing a coagulant of a polymer. Also, there is a need for a regulator or an inducer capable of efficiently controlling or controlling the characteristics of the product when the characteristics such as the basicity do not meet the intended level and are too much or too little, .

Korean Patent No. 10-0221977 (published on Sep. 15, 1999, 'Method for preparing inorganic polymer flocculant containing aluminum chloride as a main component')

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a process for producing an aluminum oxide film by oxidizing aluminum oxide and concentrated hydrochloric acid through a series of simple and efficient processes comprising mixing, The present invention relates to a process for producing a neutral basic aluminum chloride polymer flocculant having excellent properties such as aluminum content, pH, basicity, specific gravity and turbidity, and excellent flocculation efficiency, storage stability, organic matters and phosphorus removal ability, And to provide a way to do so.

(A) an aqueous solution of hydrochloric acid (HCl) in a concentration of 35% by weight or more based on 100 parts by weight of aluminum hydroxide (Al (OH) 3) Mixing the components; (b) reacting the mixed aluminum hydroxide and aqueous hydrochloric acid solution for 4 to 10 hours; (c) cooling the reaction until the temperature is between 100 and 120 < 0 >C; (d) adding diluted water to the reactant and stirring the reactant; And (e) filtering the reactant so that the turbidity of the diluted reactant is maintained at 5 NTU or less. The present invention also provides a method for producing a heavy basic aluminum chloride coagulant.

In step (b), the reaction is carried out under the condition of a pressure of 4.5 to 6.0 kg / cm 2 and a temperature of 135 to 165 ° C. In step (d), diluted water is added so that the specific gravity at room temperature (20 ° C.) The specific gravity can be adjusted.

According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: (a) providing an aqueous solution of hydrochloric acid (HCl) at a concentration of 35% by weight or more based on 100 parts by weight of aluminum hydroxide (Al (OH) 260 parts by weight; (b) reacting the mixed aluminum hydroxide and hydrochloric acid aqueous solution at a pressure of 4.5 to 6.0 kg / cm 2 and a temperature of 135 to 165 ° C for 4 to 10 hours; (c) cooling the reaction until the temperature is between 100 and 120 < 0 >C; (d) adding diluted water to the reactant so that the specific gravity at room temperature (20 ° C) is 1.19 or more and stirring the reactant; And (e) filtering the reactant so that the turbidity of the diluted reactant is maintained at 5 NTU or less. The flocculant prepared through steps (a) to (e) has a pH of 3.5 to 5.0 Wherein the polychlorotrifluoroacetic acid salt of the polychlorotrifluoroacetic acid salt of the polychlorotrifluoroacetate salt of the formula

The above-described heavy basic aluminum chloride-based polymer flocculant of the present invention and its preparation method are excellent in physical properties such as aluminum oxide content, pH, basicity, specific gravity and turbidity, and have excellent flocculation efficiency, storage stability, The excellent aluminum chloride polymer flocculant can be easily manufactured through a simple and efficient method. When it is necessary to control the product to conform to the product standard such as basicity, or to upgrade or downgrade the product standard, There are advantages that can be adjusted.

Hereinafter, examples of the heavy basic aluminum chloride polymer flocculant of the present invention and a method for producing the same will be described. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. shall.

Throughout this specification, when a member is "on " another member, this includes not only when the member is in contact with another member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including" an element, it is understood that it may include other elements as well, without departing from the other elements unless specifically stated otherwise.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

In each step, the identification code is used for convenience of explanation, and the identification code does not describe the order of the steps, and each step may be performed differently from the stated order unless clearly specified in the context. have. That is, each of the steps may be performed in the same order as described, or may be performed substantially concurrently or in the reverse order.

The method for producing the heavy basic aluminum chloride polymer flocculant of the present invention can be largely composed of a mixing step, a reaction step, a cooling step, a stirring step and a filtration step, and each step will be described in detail below.

First, in the mixing step, aluminum hydroxide (Al (OH) 3) and a concentrated hydrochloric acid (HCl) aqueous solution having a concentration of 35 wt% or more are metered and mixed. The process of inspecting the material specifications of aluminum hydroxide and concentrated hydrochloric acid added prior to mixing can be preceded. Specifically, each material is sampled three times to determine whether the appearance of the aluminum hydroxide is over the limit sample, the content of Al2O3 is 55 wt% or more, the content of iron (Fe) is 0.01 wt% or less, the content of water is 10.0 wt% Whether or not the appearance of the concentrated hydrochloric acid is not less than the limit sample, the concentration is not less than 35% by weight, the iron content is not more than 0.002% by weight, the specific gravity is not less than 1.18, have.

When the material specification inspection is completed, each material is weighed and put into the reaction tank and mixed. The added amount is preferably 220 to 260 parts by weight of concentrated hydrochloric acid aqueous solution when 100 parts by weight of aluminum hydroxide is used as a standard. The equipment to be used in the mixing step is preferably a 2 m3 specimen storage hopper, a 3 m3 specimen metering tank (load cell), a 20 m3 and 30 m3 standard hydrochloric acid storage tank, a 50 A standard hydrochloric acid flow meter, min absorption tower and the like.

After inspecting each part of the equipment, the quantity of aluminum hydroxide to be input to the load cell indicator is input, preferably 2,700 ± 100 kg. Aluminum hydroxide is then put into a hopper for storage by a forklift and the loaded raw material is transferred to a water metering hopper by a belt conveyor. Then, the absorber is operated, and the quantity of hydrochloric acid is checked with a hydrochloric acid flow meter, and it is confirmed whether it is preferably 6,500 ± 200 kg.

Hydrochloric acid is added to the reaction tank through a hydrochloric acid flow meter. When the amount of hydrochloric acid is 2/3 or more, the reaction tank switch of the aluminum hydroxide measuring hopper is turned on, and aluminum hydroxide is introduced into the reaction tank. At this time, it is preferable that the stirrer of the reaction tank is also operated to uniformly mix the raw materials. Then turn off the screw conveyor switch of the weighing hopper and lock the hydrochloric acid inlet valve. When all of the raw materials have been transferred, each valve is closed and the absorber is stopped.

Next, the reaction step is a step of reacting the charged and mixed aluminum hydroxide and hydrochloric acid aqueous solution under high temperature and high pressure conditions. The equipment to be used in the reaction process is three reactors of 8m3 standard, steam boilers of 3T / H and 10kg / cm2, and 15HP standard compressors. The reaction is preferably performed at a pressure of 4.5 to 6.0 kg / cm 2 and at a temperature of 135 to 165 ° C for 4 to 10 hours.

Specifically, the steam valve is slowly opened in the reaction tank jacket to gradually heat the reaction tank so that the pressure of the tank jacket is 4.5 to 6.0 kg / cm 2, and when the temperature in the tank is 135 to 165 ° C, the reaction time is 4 to 10 hours Drive.

Next, it is a process of cooling until the temperature of the reactant becomes 100 to 120 캜. Specifically, when the reaction time has elapsed, the steam valve is shut off, the steam in the jacket is discharged, the scraper is operated, and the steam in the tank is discharged to gradually cool until the temperature of the reactant becomes 100 to 120 ° C. When cooling is completed, the reaction liquid discharge valve is opened and the reaction liquid is transferred to the storage tank. When the transfer of the reaction liquid is completed, the reactor jacket is ventilated to cool the inside of the tank, and stirring of the reaction liquid transferred to the storage tank is started.

Next, dilute water is added to the reactant and stirred to adjust the concentration. The specific gravity of this process can be adjusted by adding diluted water so that the specific gravity at room temperature (20 ° C) is 1.19 or more.

Specifically, the process is to adjust the concentration of the product so that the final product meets the target quality and to stabilize it as a uniform product. Industrial water (diluted water) is used in this process. When the semi-finished product is transferred to the concentration adjusting tank, dilute water is added while the agitator is operated. The amount to be added is preferably 6,600 ± 200 kg. The specific gravity of the product is monitored in real time while the diluted water is added, and the specific gravity is controlled to be 1.19 or more under the room temperature condition.

When the dilution water is supplied, the operation of the agitator is stopped and the filtrate is transferred through the discharge valve. At this time, it may be directly transferred to the filtration unit, but it may be passed through a tank for intermediate inspection or an inspection device may be installed in the middle of the transport pipe to collect the product sample after concentration control, and then to check the specific gravity value.

Next, it is preferable to filtrate the diluted reaction product so that the turbidity is maintained at 5 NTU or less. For the filtration process, a facility such as a polypropylene (PP) bag filter of 24 m 3 / h standard can be used.

Specifically, the filtration (air) pump valve connected to the filtration tank is opened and a filtration pressure of 1.0 kg / cm < 2 > is preferably applied through a pressure gauge. The turbidity at the inlet of the storage tank is monitored and whether the turbidity is maintained below 5 NTU is monitored in real time to adjust the air pump pressure according to the degree of turbidity. If the pressure of the air pump tends to rise abnormally, the filter cloth should be replaced.

In the process of transferring the filtered product to the final inspection tank, it is possible to collect some samples and check the turbidity. In addition, samples of the product transferred to the inspection tank can be sampled to check the specifications of the polymer flocculant product. Preferably, it is possible to check whether the pH is 3.5 to 5.0, the specific gravity is 1.19 or more, and the like. When final product specification inspection is completed, it is transferred to the storage tank.

In the meantime, according to another preferred embodiment of the present invention, when the specifications such as the aluminum oxide content, the pH and the basicity of the final product do not satisfy the desired standard specifications, or when it is necessary to raise or lower the respective values, The 'basicity control step' may be further performed.

Specifically, in the basicity control step, a low-salt inducing agent may be added to lower the basicity of the final product as needed, or a salt-inducing agent may be added to increase the basicity of the final product. According to a preferred embodiment, the low-salt-inducing agent may be at least one selected from the group consisting of hydrochloric acid (HCl), aluminum sulfate and chlorides of the Group 2A metal element, and the high salt-inducing agent may be selected from the group consisting of sodium hydroxide (NaOH) (Re (OH) 3), and aluminum silicate.

Hereinafter, examples of inducing agents that can be used and put into the step of controlling the basicity of the present invention will be described. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. shall.

[Example A1] Low salt inducing agent: hydrochloric acid (HCl)

The basicity of the final product can be effectively lowered by adding hydrochloric acid to the aluminum chloride polymer flocculant product manufactured through the final filtration step. In this case, the reaction can be performed at a temperature of 40 to 80 ° C for 1 to 5 hours. After the reaction, the basicity can be lowered to 10 to 20% and the content of aluminum oxide can be adjusted to 9 to 11.2%. As a result, it is possible to increase flocculation performance and storage stability, minimize the generation of sludge and residual aluminum, and improve algae and organic matter removal performance.

[Example A2] Low salt inducing agent: aluminum sulfate

The basicity of the final product can be effectively lowered by adding aluminum sulfate to the aluminum chloride polymer flocculant product manufactured through the final filtration step. The preferred composition of the aluminum sulphate used may be an aluminum oxide content of 5-17% and a sulfate ion (SO42-) content of 10-50%. The amount to be added is preferably about 1 to 5 parts by weight based on 100 parts by weight of the initial aluminum hydroxide, and it is preferable to add water in an amount of 35 to 40 parts by weight.

After the addition of the aluminum sulfate, the reaction can be carried out at a temperature of 30 to 80 ° C. at a rate of 35 to 90 rpm and for a reaction time of about 0.5 to 3 hours, thereby effectively binding a sulfate ion to the aluminum chloride and thereby stabilizing the aluminum chloride polymer flocculant Can be manufactured.

The amount of aluminum oxide in the final product can be controlled to about 9 to 15%, the basicity to about 0.1 to 35%, and the content of sulfate ion to 0.001 to 3.5% by introducing the low-salt inducing agent according to this embodiment. This can increase phosphorus removal efficiency and minimize sludge generation.

[Example A3] Low salt inducing agent: Chloride of Group 2A metal element

It is possible to effectively reduce the basicity of the final product by adding a chloride of a Group 2A metal element to the aluminum chloride polymer flocculant product manufactured through the final filtration step. Preferred examples of the Group 2A metal element include magnesium (Mg) and calcium (Ca).

When the low salt inducing agent according to the present invention is added, the final polymer flocculant product is in the form of Al2MA (OH) BClC, where 6 + 2A = B + C, 0.08 ????? 0.13 and 0.01?? B??

In addition, the aluminum oxide content of the final product can be adjusted to a maximum of 5 to 25% by weight and the basicity can be adjusted to a maximum of 16% or less. Through this, the phosphorus- The problem of the high basic coagulant, which has a high weight, can be solved.

[Example B1] High salt inducing agent: sodium hydroxide (NaOH)

Sodium hydroxide (NaOH) may be added to the aluminum chloride polymer flocculant product manufactured through the final filtration step to effectively increase the basicity of the final product.

Specifically, 15 to 25 parts by weight of sodium hydroxide, 15 to 25 parts by weight of water and 1 to 5 parts by weight of magnesium hydroxide (Mg (OH) 2) are added sequentially, based on 100 parts by weight of the filtered product, Lt; 0 > C for 6 to 10 hours.

Through this process, it is possible to control the basicity of the final product up to 60 ~ 70% and the content of Al2O3 up to 10 ~ 15%, and it is effective to increase flocculation performance, storage stability and minimize sludge volume and residual aluminum.

[Example B2] High salt inducing agent: Rare earth hydroxide (Re (OH) 3)

The basicity of the final product can be effectively increased by addition of rare earth hydroxide (Re (OH) 3) to the aluminum chloride polymer flocculant product manufactured through the final filtration step. Preferred examples of the rare earth element include lanthanum (La), cerium (Ce), neodymium (Nd), and samarium (Sm).

When the rare earth hydroxide is introduced as a high salt-inducing agent, it is preferable to pre-treat the product after the filtration process with a sulfate. Specifically, 1 to 20 parts by weight of a sulfate having a sulfate ion content of 50 to 80% by weight based on 100 parts by weight of the product is reacted at a temperature of 20 to 60 ° C for 1 to 5 hours, It is preferable to add 0.1 to 10 parts by weight of a rare earth hydroxide having a concentration of 90% and then react at a temperature of 20 to 60 ° C for 0.5 to 7 hours. Preferable examples of the sulfate used include calcium sulfate (CaSO4), magnesium sulfate (MgSO4), iron sulfate (FeSO4), zinc sulfate (ZnSO4) and potassium sulfate (K2SO4).

Further, it is preferable to carry out an additional aging process even after reacting the rare earth hydroxide. Specifically, the product can be stabilized by aging for 1 to 5 hours at 30 to 60 ° C after the reaction. The powder size of the rare earth hydroxide to be used is preferably in the range of 0.1 to 10 μm, and the basicity of the final product can be adjusted up to 50 to 70%.

In this embodiment, the coagulation efficiency and the storage stability can be improved by using a relatively small amount of rare earths, which are natural minerals, and the basicity can be effectively increased through the synergy effect of the sulfate and the rare earth.

[Example B3] High salt inducing agent: aluminum silicate

It is possible to effectively increase the basicity of the final product by adding aluminum silicate to the aluminum chloride polymer flocculant product manufactured through the final filtration step.

One preferred embodiment of the aluminum silicate to be used is a compound of the form NaAAlB (SiO2) C, wherein 1????? 4, 1? B? 4 and 1? , The content of Al2O3 may be 10 to 28%, and the content of Na2O may be 10 to 25%.

The aluminum silicate may be added to the coagulant product and reacted at a temperature of 20 to 80 ° C for 1 to 10 hours. At this time, stirring is carried out through a homogenization reactor capable of maintaining the stirring speed at 500 to 30,000 rpm It is good. Further, as an additional post-treatment after the reaction, it is preferable to carry out the stabilization process at a temperature of 40 to 100 DEG C for 1 to 15 hours.

As a result, it is possible to control the aluminum oxide content of the final product up to 5 to 25% and the basicity to 50 to 90%, thereby effectively producing a polymer flocculant having a high salt resistance even with a relatively small amount of a high salt- The storage stability can be improved.

On the other hand, the aluminum silicate according to this embodiment can be produced through the following preferred embodiments. (Al (OH) 3, Al2O3 concentration 50 to 70%) 15 to 50% by weight, polyaluminosilicate such as zeolite and the like, 0.01 to 10% by weight of sodium hydroxide (NaOH, Na2O concentration 30 to 50% By weight, and the balance water, and reacting the mixture at 80 to 160 ° C for 0.5 to 10 hours.

Accordingly, it is an object of the present invention to provide an aluminum chloride polymer flocculant having excellent properties such as aluminum oxide content, pH, basicity, specific gravity and turbidity, and excellent flocculation efficiency, storage stability, And it can be effectively controlled through additional inducing agent when it is necessary to control it to conform to the product standard such as basicity or to raise or lower the product standard.

The present invention is not limited to the above-described specific embodiment and description, and various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention as claimed in the claims. And such modifications are within the scope of protection of the present invention.

Claims (3)

(a) mixing 220 to 260 parts by weight of a hydrochloric acid (HCl) aqueous solution having a concentration of 35% by weight or more based on 100 parts by weight of aluminum hydroxide (Al (OH) 3);
(b) reacting the mixed aluminum hydroxide and hydrochloric acid aqueous solution at a pressure of 4.5 to 6.0 kg / cm 2 and a temperature of 135 to 165 ° C for 4 to 10 hours;
(c) cooling the reaction until the temperature is between 100 and 120 < 0 >C;
(d) adding diluted water to the reactant and stirring the reactant;
(e) filtering the reactants so that the turbidity of the diluted reactant is maintained at 5 NTU or less; And
(f) at least one low-salt inducing agent selected from the group consisting of hydrochloric acid (HCl), aluminum sulfate and a chloride of a Group 2A metal element, sodium hydroxide (NaOH), hydroxide of a rare earth element (Re (OH) 3) and aluminum silicate nitrate to adjust the basicity of the reactant;
By weight based on the total weight of the polymeric coagulant.
The method according to claim 1,
Wherein the specific gravity is adjusted so that the specific gravity at room temperature (20 ° C) is 1.19 or more by adding diluted water in the step (d).
(a) mixing 220 to 260 parts by weight of a hydrochloric acid (HCl) aqueous solution having a concentration of 35% by weight or more based on 100 parts by weight of aluminum hydroxide (Al (OH) 3);
(b) reacting the mixed aluminum hydroxide and hydrochloric acid aqueous solution at a pressure of 4.5 to 6.0 kg / cm 2 and a temperature of 135 to 165 ° C for 4 to 10 hours;
(c) cooling the reaction until the temperature is between 100 and 120 < 0 >C;
(d) adding diluted water to the reactant so that the specific gravity at room temperature (20 ° C) is 1.19 or more, adjusting the specific gravity and stirring the reactant;
(e) filtering the reactants so that the turbidity of the diluted reactant is maintained at 5 NTU or less; And
(f) at least one low-salt inducing agent selected from the group consisting of hydrochloric acid (HCl), aluminum sulfate and a chloride of a Group 2A metal element, sodium hydroxide (NaOH), hydroxide of a rare earth element (Re (OH) 3) and aluminum silicate nitrate to adjust the basicity of the reaction product,
Wherein the coagulant prepared through steps (a) to (f) has a pH of 3.5 to 5.0.