KR102413656B1 - Manufacturing method of Eco-friendly Solid Deicing Chemical - Google Patents

Abstract

The present invention relates to a method for manufacturing an eco-friendly snow remover using an aqueous solution containing sodium acetate, and more particularly, to a granular eco-friendly snow remover by recycling sodium acetate process by-products generated in the PI manufacturing process, silicon wafer manufacturing process, LCD panel manufacturing process, etc. It relates to a manufacturing method.
The present invention produces CMA (Calcium Magnesium Acetate) and SA (Calcium Magnesium Acetate) by adding sodium acetate powder as a seed crystal while adding calcium magnesium mineral powder after making the sodium acetate-containing aqueous solution (w-soda) supersaturated Sodium Acetate) crystals are precipitated and then filtered, dried, and pulverized to produce a granular snow removal agent. In this case, the sodium acetate-containing aqueous solution (w-soda) may preferably be a sodium acetate process by-product generated and discharged from industrial processes such as PI manufacturing process, silicon wafer manufacturing process, and LCD panel manufacturing process.

Description

Manufacturing method of Eco-friendly Solid Deicing Chemical by recycling sodium acetate process by-products

The present invention relates to a method for manufacturing an eco-friendly snow remover using an aqueous solution containing sodium acetate, and more particularly, to a granular eco-friendly snow remover by recycling sodium acetate process by-products generated in the PI manufacturing process, silicon wafer manufacturing process, LCD panel manufacturing process, etc. It relates to a manufacturing method.

During snowfall, snow removal agents are used on roads for the safety of vehicles and pedestrians. Chloride-based components such as sodium chloride and calcium chloride are mainly used as snow removal agents. Because chloride-based snow removal agents are highly corrosive to metal, they cause deterioration of concrete or damage to automobiles. It also causes destruction. Despite these disadvantages, chloride-based deicing agents are still widely used due to economic feasibility. Therefore, there is a need for an economical new eco-friendly snow removal agent while minimizing the damage of the chloride-based snow removal agent.

Examples of eco-friendly snow removal agents include CMA (Calcium Magnesium Acetate) and SA (Sodium Acetate). However, CMA and SA are often used by mixing with the existing chloride-based deicing agent due to the economic burden of the acetic acid (acetic acid) material cost required for manufacturing. is becoming

On the other hand, PI (Polyimide) film is a chemical material classified as a super-engineering plastic with excellent heat resistance manufactured using PI resin. have. In PI film manufacturing, an aqueous solution containing sodium acetate is discharged as a by-product during the neutralization process. The aqueous solution containing sodium acetate discharged here is generally 40 to 60 wt% of sodium acetate, 0.01 to 0.1 wt% of acetate, and 0.01 to 0.5 wt% of DMF (Dimethylformimide). , DMA (Dimethylamine) 0.3~0.5wt%, water 35~40wt%, and other ingredients. Even in silicon wafer manufacturing, an acid mixture used as an etchant and abrasive in the etching and polishing process is generated as a waste, and in LCD panel manufacturing, a treatment solution containing phosphoric acid, nitric acid, and acetate is generated during processing. As such, in various industrial processes, process by-products containing sodium acetate are generated and discharged. These sodium acetate process by-products are generally purified and treated as waste, which increases the economic and environmental costs associated with waste treatment.

KR 10-1305589 B1 KR 10-2047675 B1

The present invention has a technical problem in providing a new eco-friendly snow removal agent that can be economically manufactured and at the same time providing a recycling method of sodium acetate process by-products treated as waste in an industrial process.

In addition, the present invention is to provide a method for manufacturing an environmentally friendly granular snow removal agent advantageous in transport, storage, etc.

In order to solve the above technical problem, the present invention provides a first step of heating and stirring an aqueous solution containing sodium acetate containing 20 to 65% by weight of sodium acetate (SA, Sodium Acetate) at 50 to 60° C. in a stirrer to make it supersaturated. ; A second step of reaction treatment by inputting calcium magnesium mineral powder; a third step of cooling the reactants of the second step and transferring them to a crystal forming vessel to maintain the temperature at 15-20°C; A fourth step of precipitating crystals by adding sodium acetate powder to the crystal forming vessel; A fifth step of filtering the solution in which crystals were precipitated in the fourth step to obtain a solid, and centrifuging the obtained solid; A sixth step of drying the centrifuged solid of the fifth step; A seventh step of sorting or pulverizing the dry material of the sixth step to a particle size of 0.6 to 13 mm; characterized in that it is made of a granular snow removal agent comprising CMA (Calcium Magnesium Acetate) powder and SA (Sodium Acetate) powder A method for manufacturing an eco-friendly snow remover is provided. Here, the first step may be preferably performed while using an aqueous solution in which harmful substances are removed from sodium acetate process by-products as an aqueous solution containing sodium acetate, and adding a corrosion inhibitor.

According to the present invention, the following effects can be expected.

First, it can be manufactured from liquid sodium acetate into an eco-friendly snow remover containing granular CMA and sodium acetate, and thus it is excellent in transport, use, storage, etc. as a granular snow remover.

Second, the snow remover manufactured according to the present invention is advantageous in minimizing corrosivity, plant reproduction effect, and soil / groundwater contamination, as well as securing equivalent or higher performance and environmental impact performance compared to existing chloride-based snow removal agents.

Third, since the sodium acetate process by-products generated and discharged from various industrial processes such as the PI manufacturing process can be recycled, economical/environmental efficiency can be secured through the processing of process by-products.

1 is a process diagram for a method for manufacturing an eco-friendly snow remover according to the present invention.

1 is a process diagram for a method for manufacturing an eco-friendly snow remover according to the present invention. As can be seen, the present invention produces CMA (Calcium Magnesium Acetate) by adding sodium acetate powder as a seed crystal while adding calcium magnesium mineral powder after making the sodium acetate-containing aqueous solution (w-soda) supersaturated. and SA (Sodium Acetate) crystals are precipitated and then filtered, dried, and pulverized to produce a granular snow removal agent. The present invention will be described in detail step by step.

1. Step 1

First, an aqueous solution containing sodium acetate (SA) is made supersaturated (step 1). Sodium acetate (SA, Sodium Acetate) containing 20 to 65% by weight of sodium acetate-containing aqueous solution is heated and stirred with a stirrer at 50 to 60 ℃ to make a supersaturated state (462 g / 100 ml or more). The sodium acetate process by-products discharged from other industrial processes such as the PI manufacturing process are generally in the state of an aqueous solution containing 20 to 65 wt% of sodium acetate, and the present invention intends to utilize these sodium acetate process by-products as they are.

In the present invention, the sodium acetate-containing aqueous solution is an aqueous solution containing 20 to 65% by weight of sodium acetate (SA, Sodium Acetate), and includes an aqueous solution containing other components in addition to sodium acetate. In particular, as the sodium acetate-containing aqueous solution, an aqueous solution in which harmful substances are removed from sodium acetate process by-products generated and discharged from industrial processes can be preferably used. For example, harmful substances such as arsenic (As), DMF (Dimethylformimide), and DMA (Dimethylamine) can be removed from the sodium acetate process by-product in aqueous solution state generated and discharged from the PI manufacturing process. Just remove it. Sodium acetate process by-products from which such harmful substances have been removed can be used for manufacturing an eco-friendly snow remover in the same manner as in the present invention, and can also be used for manufacturing CMA in the manner according to Patent No. 10-2047675.

In the first step, a corrosion inhibitor may be added and mixed. The corrosion inhibitor is to prevent corrosion caused by the snow remover. As the corrosion inhibitor, one or more of benzotriazole, sodium citrate, and sodium phosphate may be mixed and used. The input and mixing of the corrosion inhibitor in the first step is to easily and homogeneously mix the corrosion inhibitor in an aqueous solution state. If the corrosion inhibitor is mixed with the prepared snow remover powder, it is difficult to homogeneously mix unless an additional mixing and stirring process is performed because the corrosion inhibitor is small.

The corrosion inhibitor is preferably 0.01 to 0.15% by weight of an aqueous solution containing sodium acetate containing 20 to 65% by weight of sodium acetate (SA, Sodium Acetate). in order to be mixed. If the corrosion inhibitor is less than 0.1% by weight of the precipitated snow removal agent, the effectiveness as a corrosion inhibitor is insignificant and the effectiveness decreases. If it exceeds 0.5% by weight, the corrosion inhibitor is used to suppress some corrosion. does not reduce effectiveness.

2. Step 2

Calcium magnesium mineral powder is added for reaction treatment (2nd step). CMA is produced by reacting acetic acid and calcium magnesium mineral powder in an aqueous solution containing sodium acetate. As the calcium magnesium mineral, dolomite containing MgCO3 and CaCO3 as main components can be preferably used, and the mixing amount should be appropriately determined in consideration of the amount of CMA production and the amount of sodium acetate crystals precipitated. For example, based on an aqueous solution containing 40 to 45 wt% of sodium acetate, 10 to 40 wt% of dolomite is suitable. In this case, if it is less than 10 wt%, the amount of CMA production is lowered, and if it exceeds 40 wt%, sodium acetate crystals due to excessive input Since the amount of water precipitation is rather low, the characteristic expression effect as a deicing agent by appropriate mixing of CMA and sodium acetate is reduced.

3. Stage 3 and Stage 4

Crystals are precipitated from the reactant in the second step. For crystal precipitation, the reactants in the heated supersaturated state are first cooled and then transferred to a crystal forming vessel and maintained at 15-20° C. without stirring (3rd step). Then, sodium acetate powder is added to the crystal forming vessel to precipitate crystals (4th step). The added sodium acetate powder acts as a crystal seed to prevent the supersaturated reactant from being formed into microcrystals while forming and precipitating needle-shaped crystals.

It is advantageous in terms of precipitation yield to use sodium acetate powder with a particle size of 1.18 to 3.0 mm. In addition, the sodium acetate powder is preferably added in an amount of 0.001 to 0.01% by weight of the sodium acetate-containing aqueous solution of the first step. If the input amount of sodium acetate powder is less than 0.001% by weight, the crystal grain formation is slowed and it is formed to a microcrystalline level, making it difficult to form needle-shaped crystals that meet the required level. input result.

4. Step 5, Step 6 and Step 7

A granular snow removal agent containing CMA and SA is obtained from the precipitated crystals. In order to obtain a granular snow remover, first, a solution in which crystals are precipitated is filtered to obtain a solid, and the obtained solid is centrifuged (step 5). Then, the solid material separated through filtration and centrifugation is dried (step 6), and the filtered filtrate and the centrifuged separated solution are recovered and provided to the first step to be used for circulation. Finally, the dried material is screened or pulverized to a particle size of 0.6 to 13 mm (step 7), and the fine powder separated through screening or pulverization is recovered and provided to the first step, so that it can be used for circulation.

Thereby, it is manufactured as a granular snow removal agent containing CMA (Calcium Magnesium Acetate) powder and SA (Sodium Acetate) powder having a particle size of 0.6 to 13 mm. The prepared snow remover can be used as an eco-friendly snow remover, or it can be used in combination with an existing chloride-based snow remover (CaCl ₂ , NaCl).

On the other hand, there are cases of using CMA, an organic snow removal agent, to reduce fine dust emission among exhaust gases emitted from existing industrial processes or to reduce fine dust generation around roads and sidewalks in residential environments. Because it contains , it will be possible to use it in the field of application to reduce fine dust or to reduce emissions through adsorption treatment.

[Production Example] Snow removal agent production

As a by-product of the PI manufacturing process, harmful substances such as arsenic, DMA, and DMF were removed from the sodium acetate process by-product and concentrated to prepare an aqueous solution containing sodium acetate with a solid content of 45% by weight or more. Sodium acetate-containing aqueous solution prepared in this way is put into a stirrer, and a corrosion inhibitor (sodium citrate) is mixed with 0.01% by weight of sodium acetate-containing aqueous solution, heated and stirred at 50 to 60°C, and calcium magnesium mineral (dolomite) is added to sodium acetate-containing aqueous solution. 22% by weight was added to the reaction treatment. Then, the reaction-treated reactants were cooled, transferred to a crystal forming vessel, and maintained at 15-20° C. without stirring. Then, granular sodium acetate was added in 0.01 wt% of an aqueous solution containing sodium acetate to precipitate crystals. The solution in which the crystals were precipitated was filtered, and as a result, it was possible to separate 60% by weight of a solid and 40% by weight of a filtrate. The solid was centrifuged again, and as a result, it was possible to separate 10% by weight of the separated solution compared to the solid before centrifugation. The centrifuged solid material was dried under reduced pressure and separated and selected to have a particle size of 0.6 to 13 mm, and more than 13 mm was pulverized and separated and selected to have a particle size of 0.6 to 13 mm. Thus, a snow removal agent comprising 48 wt% of CMA powder and 52 wt% of SA powder was prepared.

[Test Example 1] Precipitation yield according to particle size of sodium acetate powder

When manufacturing the snow remover according to [Preparation Example 1], the crystal precipitation yield according to the particle size of the sodium acetate powder used as the crystal seed was compared and confirmed. The input amount of sodium acetate powder by particle size was 0.3% by weight compared to the sodium acetate-containing aqueous solution, and the precipitation yield was evaluated by the weight of sodium acetate crystals compared to the weight of the sodium acetate-containing aqueous solution. As a result of confirming the precipitation yield, it was shown in [Table 1] below. As can be seen, it was confirmed that the crystal precipitation yield was high when granular sodium acetate anhydride of 1.18 mm or more was used.

Precipitation yield according to particle size of sodium acetate powder particle size of sodium acetate Crystallization yield (wt%) differential less than 1.18mm 10.4 1.18~2.36mm figurine 36.3 More than 2.36mm figurine 36.8

[Test Example 2] Environmental standard characteristic evaluation of snow removal agent

The environmental standard characteristics were evaluated for the snow remover manufactured according to [Production Example 1], and the evaluation results are shown in [Table 2] and [Table 3] below. As you can see, it was confirmed that it satisfies the harmful element content standards of the snow remover standards and meets the EL610 standards.

Harmful element content standards Content by harmful element (mg/kg) Lead (Pb) Arsenic (As) Cadmium (Cd) Mercury (Hg) Cr (Cr) Copper (Cu) Nickel (Ni) Zinc (An) result N.D. <0.3 N.D. N.D. N.D. N.D. N.D. N.D. EL610
meet the standard note: N.D. (Non-Detected)

Environmental standard characteristics evaluation item Characteristic evaluation result Based on EL610 Assessment Methods Steel corrosion effect 8.1% 30% or less EM502-1 (Performance Evaluation of Snow Removal Agent - Test Method for Corrosion Effect of Steel) Concrete freeze-thaw effect (relative loss rate) 0.8% 50% or less EM502-2 (Evaluation of performance of deicing agents-Concrete freeze-thaw test method) Organic compound biodegradability 95% 80% or more KS I ISO 11733 Hazardous to the aquatic environment
(Contains Acute Class 1 Substances) free free According to EL610 Water flea 48 hours acute toxicity test (EC50 value) 304mg/L 100mg/L or more According to EL610

[Test Example 3] Evaluation of the quality standard characteristics of the snow removal agent

The quality standard characteristics were evaluated for the snow remover prepared according to [Production Example 1], and the evaluation results are shown in [Table 4] and [Table 5] below. As can be seen, it was confirmed that all of the EL610 standards were satisfied in the evaluation of the ice melting performance, particle size, and water insoluble matter.

Ice melting performance of snow remover evaluation item Test temperature (℃) Ice melting performance by test elapsed time (%) Assessment Methods 15min 30min 60min Ice melting performance - 7 100 108 111 According to EL610 - 12 100 117 128 - 15 100 116 139

The particle size and water insoluble content of the snow remover evaluation item Characteristic evaluation result Based on EL610 Assessment Methods granularity 0.6mm Sieve Residual Rate (wt%) 99.4% 98% or more According to EL610 13.0mm Sieve Residual Rate (wt%) 0% 0% water insoluble 0.14% 1.0% or less According to EL610

Claims (5)

A first step of heating and stirring an aqueous solution containing sodium acetate containing 20 to 65% by weight of sodium acetate (SA, Sodium Acetate) at 50 to 60° C. in a stirrer to make it supersaturated;
A second step of reaction treatment by adding calcium magnesium mineral powder;
a third step of cooling the reactants of the second step and transferring them to a crystal forming vessel to maintain the temperature at 15-20°C;
A fourth step of adding sodium acetate powder having a particle size of 1.18 to 3.0 mm into a crystal forming container to precipitate crystals, and adding sodium acetate powder to 0.001 to 0.01 wt % of an aqueous solution containing sodium acetate;
A fifth step of filtering the solution in which crystals were precipitated in the fourth step to obtain a solid, and centrifuging the obtained solid;
A sixth step of drying the centrifuged solid of the fifth step;
A seventh step of sorting or pulverizing the dry matter of the sixth step to a particle size of 0.6 to 13 mm; consists of,
An eco-friendly snow remover manufacturing method, characterized in that it is manufactured as a granular snow remover comprising CMA (Calcium Magnesium Acetate) powder and SA (Sodium Acetate) powder. In claim 1,
The first step is an environmentally friendly snow remover manufacturing method, characterized in that the aqueous solution containing sodium acetate is an aqueous solution from which harmful substances have been removed from the sodium acetate process by-product, and the corrosion inhibitor is added. delete In claim 1 or 2,
The filtrate filtered through the fifth step and the centrifuged separation solution; The fine powder separated through the seventh step is recovered and provided in the first step. An eco-friendly snow remover comprising an eco-friendly snow remover manufactured according to claim 1 or 2.

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