KR102132191B1 - Manufacturing mehtod of fertillzer from ammonium nitrate waste - Google Patents

Abstract

The present invention relates to a method for producing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process, and more specifically, removing and obtaining heavy and rare metals such as iron, chromium, indium, and gallium from ammonium nitrate waste. At the same time, high-purity regenerated ammonium nitrate is obtained, concentrated and purified, and applied to fertilizer, so that not only can resources be recycled, but also environmental pollution can be prevented. Production of fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process It's about how.
The method of manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process according to the present invention includes a pre-treatment step (S100) of removing impurities and heavy metals from ammonium nitrate waste; and ammonium nitrate waste from which impurities and heavy metals are removed and Neutralization dissolution and neutralization step (S200); and filtration step of filtering dissolved and neutralized ammonium nitrate waste (S300); and solvent filtering of the filtered ammonium nitrate waste filtrate to extract valuable metals such as indium (In) and gallium ( Ga) extraction and removal of valuable metals to extract and remove (S400); and concentration step to concentrate the filtrate from which indium and gallium is extracted and removed (S500); and concentrated filtrate prepared as fertilizer or microbial nutrient It includes a processing step (S600).

Description

Manufacturing method of fertilizer using ammonium nitrate waste generated from metal oxide manufacturing process {MANUFACTURING MEHTOD OF FERTILLZER FROM AMMONIUM NITRATE WASTE}

The present invention relates to a method for producing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process, and more specifically, removing and obtaining heavy and rare metals such as iron, chromium, indium, and gallium from ammonium nitrate waste. At the same time, high-purity regenerated ammonium nitrate is obtained, concentrated and purified, and applied to fertilizer, so that not only can resources be recycled, but also environmental pollution can be prevented. Production of fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process It's about how.

In general, transparent conducting oxide (TCO) has high transmittance and excellent electrical properties in the visible region, so it is a liquid crystal display (LCD), a plasma display panel (PDP), a solar cell, and a light emitting device (light). It is used as a transparent electrode in emitting diodes, LEDs, etc., and has high utilization in various fields such as low-emissitivity windows, touch-control panels, and electro-magnetic shields. It is an indispensable material to realize the high added value that is indispensable to the mid- and long-term display industry development.

Currently, TCO accounts for more than 90% of ITO (Indium-Tin Oxide), which has excellent light transmittance, conductivity, and favorable pattern formation. Indium Gallium Zinc (IGZO) has been studied for research on alternative materials and processes for ITO. Oxide) is in progress.

On the other hand, the metal oxide (Metal Oxide) manufacturing process is an indispensable material for the LCD, PDP, touch panel, and OLED industries as the raw material for the ITO (Indium TIn Oxide) and IGZO target manufacturing process, and is essentially an ammonium nitrate waste in the manufacturing process. This happens.

However, in the electrical and electronics industry, ammonium nitrate waste generated in the metal oxide process is mainly treated by landfill and neutralization, causing environmental pollution, and such environmental pollution is emerging as a social problem.

Therefore, many attempts and developments have been made to recycle such wastes, and Patent Literature 1 as related prior art is neutralized using 25% NaOH solution after leaching with hydrochloric acid using IGZO scrap as a starting material. A method of producing gallium metal through electrolysis of a gallium-containing solution generated by filtration is disclosed, and patent document 2 uses batch-type vacuum for high concentrations of indium-containing waste acid generated during the manufacturing process of an ITO (Indium-Tin Oxide) thin film. A method for recovering indium and acid by vacuum evaporation and concentration of indium-containing waste acid, which is an environmentally friendly method that recovers high-purity indium using evaporation and concentration facilities and uses the recovered acid for recycling, has been proposed.

On the other hand, UAN (Urea Ammonium Nitrate) is a liquid fertilizer mixed with urea (urea) and ammonium nitrate (38% to 42% ammonium nitrate, 28% to 32% urea, and 26 to 34% water). Define liquid fertilizers ranging from 28% to 32%. Currently, there is no domestic production and sales, and it is manufactured (8,000,000~10,000,000t/year) by four major nitrogen-based fertilizer companies from CF Industries, Farmland, Arcadian, and Terra. The main producers are the United States, Ukraine, China, etc. It is used in North America, Southeast Asia, India, and Australia.

Ammonium nitrate in Korea is well soluble in water and used as fertilizer for hydroponic cultivation and nutrient solution cultivation, but for domestic consumption, about 10,000 tons/year is used, and production and quality improvement of ammonium nitrate is currently required.

The present inventor dissolves and neutralizes the ammonium nitrate waste in Publication 10-2017-0060834 (Patent Document 3) as part of a study for fertilizing waste ammonium nitrate, a waste generated in the display electronics industry process, and extracts the solvent. After removing the metal, the recycling method for using the filtrate as a composite fertilizer and a UAN (Urea Ammonium Nitrate) fertilizer has been proposed.

However, the ammonium nitrate produced by the recycling method contains heavy metals and impurities, and the concentration of ammonium nitrate obtained is also low, which has an unsuitable limit for use without further processing as fertilizer.

Accordingly, the present inventor has developed a recycling method to minimize impurities and heavy metal content in ammonium nitrate waste and concentrate to obtain high purity and high concentration of ammonium nitrate, and the ammonium nitrate produced by the recycling method is a separate additional process. It has been confirmed that it is suitable for application to UAN fertilizers and microbial nutrients without treatment, leading to the invention.

Patent Document 1: Japanese Patent Application Laid-open No. 2012-193396 (Method for manufacturing metal gallium) Patent Document 2: Korean Patent No. 10-1251887 (Indium and acid recovery method by vacuum evaporation and concentration of indium-containing waste acid) Patent Document 3: Domestic Publication No. 10-2017-0060834 (Recycling method of ammonium nitrate waste)

The object of the present invention for solving the above problems is to remove and obtain heavy metals and rare metals such as iron, chromium, indium and gallium from ammonium nitrate waste generated in the metal oxide manufacturing process, and at the same time to obtain high purity regenerated ammonium nitrate. It is to provide a recycling method of ammonium nitrate waste that is obtained, concentrated and purified, and applied to fertilizers to not only recycle resources but also prevent environmental pollution.

The method for manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process of the present invention for solving the above problems is a pre-treatment step (S100) for removing impurities and heavy metals from ammonium nitrate waste; and nitric acid from which impurities and heavy metals are removed Dissolving and neutralizing step of dissolving and neutralizing ammonium waste (S200); and filtering step of filtering dissolved and neutralized ammonium nitrate waste (S300); and extracting the filtered ammonium nitrate waste filtrate as a solvent to indium, a valuable metal ( In) and gallium (Ga) extracting and removing valuable metals extracting and removing step (S400); and concentration step (S500) for concentrating the filtrate from which indium and gallium is extracted and removed; and fertilizer using concentrated filtrate as a raw material Or it includes a processing step (S600) for manufacturing with a microbial nutrient.

The pre-treatment step (S100) is a first pre-treatment step (S110) to remove the filtrate containing the iron component by filtering the precipitate formed by adding an alkaline solution to pH 3 to 4 to ammonium nitrate waste; and a first pre-treatment step It includes a second pre-treatment step (S120) to remove the heavy metal by introducing a surfactant to the filtrate generated by forming agglomerates adsorbed by heavy metals and filtering the precipitate after cooling and precipitation.

In the dissolving and neutralizing step (S200), 1 to 50 parts by weight of ammonium nitrate waste is added to 100 parts by weight of nitric acid (HNO3) and dissolved by stirring at a temperature of 60 to 90°C for 1 to 24 hours, followed by ammonia (NH3). It is characterized by neutralizing to a pH of 7 to 8.

In the step of extracting and removing the valuable metal (S400), 20 to 200 weight of solvent alone or in combination of two or more of them in trialkylphosphine-based solvent, oxime-based solvent or phosphoric acid-based solvent, based on 100 parts by weight of the filtered ammonium nitrate waste filtrate It is characterized in that it is made by adding and adding a portion and stirring for 30 minutes to 2 hours at a rate of 500 to 1,500 rpm to obtain and remove the concentrated solution from which indium (In) and gallium (Ga) are extracted.

The concentration step (S500) includes a first concentration step (S510) of evaporating and concentrating the filtrate in which indium and gallium are extracted and removed; and a second concentration step (S520) of concentrating the evaporated concentrate using electrodialysis; It is characterized by.

The second concentration step (S520) is characterized in that, during electrodialysis, the ion exchange resin uses any one of CMX ^® , CM-1 ^® , Selemin CMV ^® and combinations thereof.

The urea-ammonium nitrate mixed fertilizer for solving the above problems is characterized in that the present invention is produced using ammonium nitrate obtained by the method for producing fertilizer using ammonium nitrate waste.

As described above, according to the method for producing fertilizer using ammonium nitrate waste generated in the metal oxide production process according to the present invention, heavy metals and rare metals such as iron, chromium, indium and gallium are removed and obtained from ammonium nitrate waste At the same time, high-purity regenerated ammonium nitrate is obtained, concentrated and purified, and applied to fertilizer, thereby recycling resources as well as preventing environmental pollution.

1 is a flow chart showing a method of manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process according to the present invention.
Figure 2 is a graph showing the change in the concentration of iron ions according to (a) iron content ICP-OES results and (b) pH in the pretreatment step (S100) according to the present invention.
Figure 3 is a graph showing the chromium removal efficiency according to (a) chromium content ICP-OES results and (b) S/M in the pretreatment step (S100) according to the present invention.
4 is a photograph of the evaporation and concentration equipment applied in the concentration step (S500) according to the present invention.
5 is a graph showing the selectivity of the ion exchange membrane in the concentration step (S500) according to the present invention.
6 is a graph showing the electrodialysis efficiency in the concentration step (S500) according to the present invention.
7 is a photograph of ammonium nitrate purified and concentrated filtrate and UAN fertilizer prepared in a method for producing fertilizer using ammonium nitrate waste generated in the metal oxide production process according to the present invention.

Specific features and advantages of the present invention will be described in detail below with reference to the accompanying drawings. Prior to this, when it is determined that the detailed description of the functions and configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

The present invention relates to a method for producing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process, and more specifically, removing and obtaining heavy and rare metals such as iron, chromium, indium, and gallium from ammonium nitrate waste. At the same time, high-purity regenerated ammonium nitrate is obtained, concentrated and purified, and applied to fertilizer, so that not only can resources be recycled, but also environmental pollution can be prevented. Production of fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process It's about how.

1 is a flow chart showing a method of manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process according to the present invention.

The method of manufacturing fertilizer using ammonium nitrate waste generated in the process of manufacturing metal oxide according to the present invention is a pretreatment step (S100) of removing impurities and heavy metals from ammonium nitrate waste and dissolving and neutralizing ammonium nitrate waste from which impurities and heavy metals are removed Dissolving and neutralizing step (S200) and filtration step (S300) for filtering dissolved and neutralized ammonium nitrate waste and solvent extraction of the filtered ammonium nitrate waste filtrate to remove valuable metals such as indium (In) and gallium (Ga). Extraction and removal of valuable metals (S400) and concentration steps (S500) to concentrate the filtrate from which indium and gallium are extracted and removed, and processing steps to produce fertilizer or microbial nutrients using concentrated filtrate as a raw material (S600) ).

In the pretreatment step (S100), impurities and heavy metals, such as chloride, Fe, and Cr, contained in the ammonium nitrate waste are removed to improve reactivity with the solvent in the dissolution and neutralization step (S200), which is a dissolution and neutralization process, and filtration. In step S300, the filtration efficiency is improved, and in the step of extracting and removing valuable metals (S400), it is possible to improve the extraction efficiency and purity of the valuable metals as well as to improve the quality of the final fertilizer.

In addition to valuable metals such as indium and gallium contained in the ammonium nitrate waste, impurities such as Cl, Na, K, and Ca are included, and among these, Cl interferes with filtration during acid leaching or when heat is applied to dioxins. It is involved in the production of toxic substances such as Na and K, and alkali metals such as Na and K have high solubility, so it is not easy to remove from the solution phase, and Ca, which is an alkaline earth metal, increases the consumption of acid, thereby improving process efficiency as described above by removing impurities. I can do it.

The impurities can be removed through a simple washing process, but preferably, the sodium hydroxide at a concentration of 1 to 2N is injected and stirred for 10 to 30 minutes while maintaining the pH at 9 to 11, followed by washing with water to further improve the removal efficiency of impurities. I can do it.

In addition, the ammonium nitrate waste contains about 30 to 200 ppm of heavy metals such as iron (Fe), chromium (Cr), etc., and is formed by adding an alkaline solution to pH 3 to 4 in the ammonium nitrate waste to remove the heavy metal. Formation of agglomerates with Cr and residual heavy metals adsorbed by adding surfactant to the filtrate generated by the first pretreatment step (S110) and the first pretreatment step to remove the filtrate containing the iron component by filtering the precipitate and cooling and settling After that, a second pretreatment step (S120) of removing heavy metals by filtering the precipitate is included.

In the first pretreatment step (S110), the ammonium nitrate waste is injected with an alkali solution to a pH of 3 to 4 to maintain the precipitate for 10 to 120 minutes to filter the resulting precipitate to remove precipitates containing iron components. At this time, the alkali solution is injected so that the pH is 3 to 4, it is difficult to form a precipitate below pH 3, and when it exceeds pH 4, the formation of the precipitate compared to the increase in pH and the removal rate of the iron component is negligible. It is preferred not to fall outside the pH range.

In the second pre-treatment step (S120), the precipitate is removed in the first pre-treatment step, and a surfactant is added to the remaining filtrate to form aggregates in the form of adsorbing heavy metals on the micelles, and the precipitates are cooled and precipitated to filter the precipitates. Other heavy metals can be efficiently removed.

In this case, the surfactant may use any one of anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and combinations thereof. More preferably, the heavy metal component of the cation is effectively removed by electrostatic attraction. Anionic surfactants capable of easily separating and separating by forming adsorption and agglomerates can be used.

The anionic surfactant is any one of carboxylic acid salts (RCOO ^- M ⁺ ), sulfonic acid salts (RSO3 ^- M ⁺ ), sulfate ester salts (ROSO3 ^- M ⁺ ), phosphoric acid ester salts (RPO3 ^- Na2 ⁺ ), and combinations thereof. It may be selected, and specific examples include Sodium Dodecyl Sulfate (SDS), Ammonium Lauryl Sulfate (ALS), Sodium Lauryl Ethylene Sulfate (SLES), and Linear Alkyl Benzene. Linear Alkylbenzene Sulfonate (LAS), Alpha-Olefin Sulfonate (AOS) Alkyl Sulfate (AS), Alkyl Ether Sulfate (AES), Sodium Alkane Sulfonate Sulfonate;SAS) and combinations thereof, but it is not limited thereto. More preferably, sodium dodecyl sulfate (SDS) may be used.

The addition amount of the surfactant is added to have a S/M (surfactant/metal) molar ratio of 6 to 10: 1, and if the amount of the surfactant is less than the above range (less addition), it is difficult to obtain and adsorb heavy metals and obtain the above range. In the case of excess (if added a lot), it is preferable not to fall within the above range for process efficiency because the effect of adsorption and separation of heavy metals with increasing content is negligible.

Filtering the sludge primarily while maintaining the pH 6 to 8 while reacting with the surfactant and injecting sodium hydroxide, and cooling the filtrate at 3 to 5° C. for 3 to 6 hours to cool and precipitate the aggregate adsorbed by the heavy metal, followed by filtration. Is ordered.

The surfactant may be performed for 6 hours to 15 hours from the time of injection to the filtration separation of the aggregate, more preferably, the initial injection (20% of the total reaction time from the beginning) of the entire reaction time is 150 at 30 to 35°C. The mixture was stirred at 300 rpm to uniformly disperse the surfactant in the filtrate, filtered impurities first while maintaining pH 6 to 8 while injecting sodium hydroxide, and stopped stirring until the total reaction time exceeded 20% to 50%. , By standing at room temperature (20 to 25°C), the heavy metal component is stably adsorbed to the surfactant's micelles to form agglomerates, and the total reaction time exceeds 50% and ends at 3 to 5°C. The aggregate is cooled and precipitated. Preferably, the cooling precipitation process may be performed for 3 to 6 hours.

The iron precipitate obtained in the first pretreatment step (S110) and the aggregate containing chromium and heavy metal obtained in the second pretreatment step (S120) are obtained through solid-liquid separation and a filtration process using ion exchange resin, and the filtration process is performed. Through this, the quality of fertilizer can be improved by minimizing the impurity content of the final product.

In addition, iron, chromium and heavy metals are obtained in the form of precipitates by dissolving and repeatedly washing with water at 30 to 50° C. in lukewarm water to separate and utilize iron, chromium and heavy metals from the obtained precipitates and aggregates, or By floating and separation, the micelles can be removed with suspended sludge, and iron, chromium and heavy metals precipitated at the bottom can be obtained.

The dissolving and neutralizing step (S200) is a step of dissolving and neutralizing ammonium nitrate waste from which impurities and heavy metals have been removed. More specifically, after dissolving by introducing ammonium nitrate waste into nitric acid (HNO3), the pH is 7 to 8 It is neutralized by adding ammonia (NH3) until it is formed to form a dissolved solution in which nitric acid, ammonium ions, and valuable metals are dissolved.

When dissolved, 1 to 50 parts by weight of ammonium nitrate waste is added to 100 parts by weight of nitric acid (HNO3) and dissolved by stirring for 1 to 24 hours at a temperature of 60 to 90°C. When the dissolution conditions are less than the above range, ammonium nitrate waste There is a fear that it does not dissolve properly, and when it exceeds the above range, the removal rate of indium (In) and gallium (Ga) is no longer increased in proportion to the excess range of the above conditions, so there is a fear that it is uneconomical.

In the filtration step (S300), the dissolved and neutralized ammonium nitrate waste is filtered and separated into a solid residue and a filtrate, and the filtering method is not limited as long as it can be separated into a filtrate (solid residue) and a filtrate. Alternatively, a filter press can be used.

A filter press is a pressurized filtration device that puts a substance to be filtered between filter cloths and applies pressure to separate solids, and its operation method is known and detailed description is omitted.

The solid-liquid separation step (S200) is performed under a filter cloth size of 50 to 200 mesh and a pressure of 2 to 15 kgf/cm 2, and the solid-liquid separation efficiency is excellent under the filter cloth size and pressure conditions.

More specifically, when the size of the filter cloth exceeds 200 mesh, frequent clogging of the filter cloth occurs, so that the filtering efficiency is lowered. When the size of the filter cloth is less than 50 mesh, the separation ability of the solid residue is lowered, so that it is preferable not to exceed the size of the filter cloth. .

In addition, when the pressure of the filter press is less than 2 kgf/cm 2, the filtration efficiency decreases, and when the pressure exceeds 15 kgf/cm 2, it is difficult to expect an increase in the solid-liquid separation efficiency due to pressure increase, and unnecessary power consumption is generated. Therefore, it is preferable not to fall outside the pressure range.

The valuable metal extraction and removal step (S400) is a step of extracting and removing indium (In) and gallium (Ga), which are the valuable metals contained in the filtrate, by solvent extraction of the filtrate formed by the filtration step (S300).

The solvent extract may use any one or more of trialkylphosphine-based solvent, oxime-based solvent, phosphoric acid-based solvent, and combinations thereof, and more specifically, di(2-ethylhexyl)phosphate acid (di(2-ethylhexyl) )phosphate acid) based solvent, mono(2-ethylhexyl)phosphate acid based solvent, hydroxynanyl acetophenone oxime based solvent, trialkyl Phosphine (trialkylphosphine) solvent, trioctylphosphine solvent, bis(2,4,4-xmflapxlfvpsxlf)phosphinic acid (Bis(2,4,4-trimethylpenthyl) phosphinic acid), di-2ethylhexyl Phosphonic acid (di-2ethyl hexyl phosphoric acid) based solvent, 2-ethyl hexyl phosphinic acid based solvent, mono-2-ethyl hexyl ester based solvent, di -2,4,4-trimethylpentylphosphinic acid (di-2,4,4-trimethyl penthyl phosphinic acid) solvent and di-2,4,4-trimethylpentyl monothiophosphinic acid (di-2,4,4 -trimethyl penthyl monothiophosphinic acid) solvent, or one or more of them can be used.

Preferably, the trialkylphosphine-based solvent is Cyanex 932 (Trialkylphosohine oxide) manufactured by SYTEK of the United States, Lix 973 (5-dodecyl-salicylad oxime) manufactured by Henkel, Germany as an oxime-based solvent, or a phosphoric acid-based solvent. Can use di(2-ethylhexyl)phosphate (D2EHPA) from SYTEK.

With respect to 100 parts by weight of the filtered ammonium nitrate waste filtrate, 20 to 200 parts by weight of the solvent extract was added and stirred at a rate of 500 to 1,500 rpm for 30 minutes to 2 hours to extract indium (In) and gallium (Ga). Concentrates can be obtained and removed.

At this time, if the content and agitation conditions of the solvent extract are less than the above range, there is a fear that indium (In) and gallium (Ga) may not be properly removed, and if exceeded, indium (In) and gallium (Ga) in proportion to the excess range ), the removal rate does not increase any more, so there is a fear that it is not economical.

The recovery of indium from the obtained concentrate is dissolved in an acid solution using an indium recovery facility, and is recovered by substituting indium by immersing it in an aluminum or zinc plate, which is a metal plate having an ionization tendency larger than indium. The acid solution used may be selected from one or more of nitric acid, hydrochloric acid, hydrofluoric acid, sulfuric acid and acetic acid having a concentration of 3 to 7M.

The recovery of gallium can be carried out using electrolytic collection, wherein the electrolytic collection process is performed under a current density of 200 to 1,500 A/㎥ using an insoluble electrode plate such as SUS, and the pH of the electrolytic solution is 9 to 13, Preferably, 12 to 13 is preferable because electrolysis can be easily performed.

The concentration step (S500) is a step of concentrating the concentration of ammonium nitrate contained in the filtrate to 20% or more by evaporating and concentrating the filtrate in which indium and gallium are extracted and removed.

In the concentration step (S500), the evaporation concentrate formed through the first concentration step (S510) and the first concentration step (S510) in which the filtrate from which indium and gallium is extracted and removed is evaporated and concentrated is concentrated using electrodialysis. It includes a tea concentration step (S520).

The first concentration step (S510) is a step in which ammonium nitrate contained in the filtrate is compared with the filtrate by first concentrating ammonium nitrate by introducing the filtrate from which indium and gallium has been extracted and removed into an evaporator. 20 to 40% higher.

At this time, in the first concentration step (S510), it is concentrated for 12 to 36 hours under the evaporator temperature of 60 to 150°C. Below the temperature and time, it is difficult to obtain a high concentration of ammonium nitrate compared to the unit volume, and the temperature and time In the case of exceeding, it is preferable not to fall within the above range due to the high energy denaturation of the filtrate or the concentration effect with increasing temperature and time is insignificant.

The second concentration step (S520) is a step of secondarily concentrating the evaporated concentrate formed by the first concentration step (S510) using electrodialysis, and fertilizer concentration of less than 10% ammonium nitrate by the process. It can be concentrated to have more than 20% suitable for use in.

During electrodialysis, the ion exchange resin may be used as a cation exchange resin, preferably, a cation exchange resin having a membrane resistance of 0.5 to 3.5 Ω·cm 2, and specific examples include CMX ^® , CM-1 ^® , Either Selemin CMV ^® or a combination thereof can be used.

In the processing step (S600), the concentrated filtrate is used as a raw material to produce fertilizer or a microbial nutrient, and the ammonium nitrate filtrate is produced according to the fertilizer process standard (Rural Development Administration Notification No. 2013-5, 2013214). As a nutrient for microorganisms necessary for wastewater purification by mixing with urea (Ures) and water to prepare UAN (Urea Ammonium Nitrate) fertilizer, or by adding P (phosphate) and minerals (K, Ca, Mg) Can be applied.

Meanwhile, the compound fertilizer refers to a fertilizer containing two or more components among three elements of fertilizer, and there are four types of compound fertilizer in the process standard. The fourth kind is a complex fertilizer composed of a liquid agent, a hydrating agent, and a water-soluble agent, and refers to a fertilizer produced by mixing purified ammonium nitrate with components such as mineral, potassium, and phosphorus. . The main customers are used for nutrient farming and foliar farming.

In addition, UAN (Urea Ammonium Nitrate) fertilizer is a liquid fertilizer mixed with urea and ammonium nitrate, and generally defines a liquid fertilizer having a nitrogen concentration of 28% to 32%.

Here, the manufacturing content of the complex fertilizer, the manufacturing content of the UAN fertilizer, and the content of TN and P are very variable depending on the fertilizer process standard, the UAN fertilizer product specification, the use environment of the fertilizer or nutrient, the purpose of use, and the amount of use. It is not limited to, it can be applied to a variety of standards and contents already known.

Hereinafter, as another aspect for achieving the above object, the urea-ammonium nitrate mixed fertilizer of the present invention is produced by mixing ammonium nitrate and urea obtained by the method for producing fertilizer using ammonium nitrate waste as described above. The description thereof will be omitted as described above.

Hereinafter, the present invention will be described in detail with reference to one preferred embodiment. However, the following examples are intended to specifically illustrate the present invention, but are not limited thereto.

1. Pretreatment of ammonium nitrate waste

Raw materials (ammonium nitrate waste) were supplied and received by companies producing waste ammonium nitrate in Gumi and Gyeongbuk, and the nitrogen concentration, water and heavy metal contents are shown in Table 1 below.

Most of the raw materials were present in the form of waste liquid and sludge, and the pH was found to contain 3.5-12.5, 200-300 rpm indium, and 250-350 ppm gallium. In addition, other impurities such as Ca and Na were also included, and other metals were insignificant or hardly detected.

1-1. Setting of Fe component removal condition by pH adjustment

Samples from 5 companies were mixed in a 1:1:1:1:1 ratio, and then experiments were conducted. The pH of the raw material was found to be 2.2, and the Fe content analysis according to the pH was analyzed through ICP-OES. Figure 2 is a graph showing the change in the concentration of iron ions according to (a) ICP-OES results and (b) pH for iron content analysis in the pretreatment step (S100) according to the present invention. As a result of analysis, it was found that the lower the pH, the higher the Fe content, but about 20% at pH 3, about 45% at pH 3.5, and 90% or more at pH 4.0. There was no significant change in removal rate after pH 4.0. The reason for this is considered that most of them are present in the form of Fe3+ under a low pH condition, and as the pH increases, Fe3+ reacts with a hydroxyl group and thus is present as a precipitate.

1-2. Heavy metal by cooling precipitation method using SDS( Cr )

The amount of SDS added to the waste ammonium nitrate solution was administered using the S/M ratio, that is, the molar ratio of surfactant/metal, for synthetic waste water and a single element solution. The wastewater in which SDS was added was adjusted to pH 7 using NaOH to remove sludge using a general filter paper. The filtrate was refrigerated at 4° C. for about 5 hours to induce cooling precipitation of SDS. SDS eluted by a decrease in solubility due to low temperature is aggregated and precipitated into a large lump that is visible. At this time, heavy metals are adsorbed around the hydrophilic group of micelles composed of SDS, and condensation and precipitation occur together. When it is filtered using MF, most heavy metals are not filtered and remain on the sludge to be removed. SDS remaining in the filtrate was adsorbed and removed using an anion exchange resin (Amberlite IRA420). The S/M ratios were 2, 4, 6, 8, and 10, respectively.

Figure 3 is a graph showing the chromium removal efficiency according to (a) chromium content ICP-OES results and (b) S/M in the pretreatment step (S100) according to the present invention, Cr increases the removal rate as the S/M ratio increases This was improved. The S/M ratio was removed from 2 to 52.5%, and the S/M ratio was removed from 4 to 78%. The S/M ratio showed a high removal efficiency of about 96% or more at 6 to 10, but the S/M ratio is considered to be the most effective at 6 in terms of efficiency.

2. Dissolution and filtration steps

With respect to 100 g of nitric acid (HNO3) solution, 25 g of ammonium nitrate waste was added and dissolved by stirring at 65 DEG C for 12 hours, and then ammonia (NH3) was added to neutralize to pH 7-8. The dissolved and neutralized ammonium nitrate waste was separated into a solid residue and a filtrate using a filter press. In this case, the filter press used a JDFP-4.1-MA model plate size of 790*800 mm, a chamber volume of 4,100ℓ/cycle, and a processing speed of 1.5 Ton/Hr per hour. The size of the filter cloth pores was performed under 50 to 200 mesh and 10 to 15 kgf/cm 2 pressure.

3. Extraction and removal of valuable metals

In order to select a solvent for extracting indium, as shown in Table 2 below, the indium extraction efficiency of the solvents Cyanex-923, Lix-84I, D2EHPA, and PC-88A was confirmed. In was used to have a concentration of 1500mg / kg, the reaction and stirring (500rpm) time was 30 minutes, A / O ratio was set to 1.

As a result, it was confirmed that D2EHPA is the most suitable extraction solvent for selectively extracting In.

In order to confirm a suitable mixing ratio of the extraction solvent D2EHPA, a mixing ratio was selected as shown in Table 3 below, and indium extraction efficiency was confirmed.

In was used to have a concentration of 1500mg / kg, 30 minutes of reaction and agitation (500rpm) time, had a 30 minutes standing time.

As a result, it was confirmed that as the content of the extraction solvent increased, the amount of indium extracted increased, and when the extraction solvent was added in an amount of 50 parts by weight or more compared to 100 parts by weight of the filtrate, it was confirmed that the extraction was more than 90%.

4. Concentration step

4-1. Evaporation

The processing capacity is 200 liter/hr, square type 1300W*3000D*500H, Teflon coating, stainless steel 304 SUS, acid-resistant material, and evaporative concentration is performed using an evaporative concentrator equipped with 10 electric heaters of 5kW/h. Did. Figure 4 shows the evaporation and concentration equipment applied in the concentration step (S500) according to the present invention.

The temperature of the evaporator was controlled at 90 to 110°C and concentrated for 14 hours to increase the concentration of ammonium nitrate contained in the filtrate from 3% to 9%.

4-2. Optimal conditions for ion exchange membrane for high concentration concentration

In order to use it as a fertilizer raw material, it is necessary to concentrate it at a high concentration of 20% or more. Therefore, the selectivity of the ion exchange membrane according to the concentration change was measured to proceed to select an ion exchange membrane effective for high concentration concentration. As the cation exchange membrane, the selectivity of the ion exchange membrane according to the concentration was compared by changing the NaCl concentration for Neosepta CMX, CM-1 (Tokuyama Soda Co), and Selemion CMV (Asahi Glass Co).

Table 4 below shows the properties of the cation exchange membrane.

5 is a graph showing the selectivity of an ion exchange membrane. The selectivity decreased with increasing NaCl concentration. Among the membranes used in the experiment, ion selectivity was found in the order of CMX> CM-1> CMV.

4-3. Concentration of ammonium nitrate through electrodialysis

It was evaluated whether the electrodialysis process was effective to concentrate ammonium nitrate to 20% or more. Electrodialysis was performed using CMX ion exchange resin, and 2L of 8% ammonium nitrate solution was filled in a dilution tank and electrodialysis was performed at each concentration while changing the concentration of ammonium nitrate in the concentration tank to 15, 20, 25, 30, 35%. The current efficiency according to the concentration change of the concentration tank was measured.

FIG. 6 shows a graph showing the electrodialysis efficiency. As a result of evaluating and evaluating the average current efficiency of 1 hour through the results of electrodialysis experiments performed at each concentration, the electric efficiency increases as the concentration of the concentration tank increases from 15% to 35%. The trend decreased to 97.1, 93.2, 92.0, 90.1, 89.9, and 88.0%, respectively. According to the analysis based on the results of previous studies, it is known that it does not affect the process within about 90%. Therefore, it was expected that an ammonium nitrate concentrate of 30% or more could be obtained when the CMX membrane used in this experiment was concentrated by electrodialysis.

Based on the above results, the concentrated filtrate according to the embodiment of the present invention was subjected to electrodialysis concentration using a CMX membrane, and the filtrate having an ammonium nitrate concentration of 9% was able to obtain a concentrated filtrate having an ammonium nitrate concentration of 23% (FIG. 7(a)), it was possible to confirm the applicability as a fertilizer by adding urea and distilled water, etc. to meet the UAN product standard without removing impurities and concentrating to the concentrated filtrate. (b) city).

As described above, the present invention has been mainly described with reference to the accompanying drawings, but a person having ordinary knowledge in the technical field to which the present invention pertains does not depart from the technical spirit and scope described in the claims of the present invention. In the present invention can be carried out by various modifications or variations. Accordingly, the scope of the invention should be construed by the claims set forth to cover many examples of these variations.

Claims (7)

In the manufacturing method of fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process,
A pre-treatment step of removing impurities and heavy metals from ammonium nitrate waste (S100); and
Dissolution and neutralization step (S200) of dissolving and neutralizing ammonium nitrate waste from which impurities and heavy metals have been removed; and
Filtration step of filtering the dissolved and neutralized ammonium nitrate waste (S300); And
A valuable metal extraction step (S400) of extracting the filtered ammonium nitrate waste filtrate as a solvent to extract indium (In) and gallium (Ga) as valuable metals; and
A concentration step (S500) of concentrating the filtrate from which indium and gallium have been removed; and
It includes a processing step (S600) for producing fertilizer or microbial nutrients using the concentrated filtrate as a raw material,
The pre-processing step (S100)
A first pre-treatment step (S110) of removing the filtrate containing the iron component by filtering the precipitate formed by adding an alkali solution to the ammonium nitrate waste to a pH of 3 to 4; and
Including the second pre-treatment step (S120) to remove heavy metals by adding a surfactant to the filtrate generated by the first pre-treatment step to form agglomerates adsorbed by heavy metals and filtering the precipitate after cooling precipitation.
The second pre-processing step (S120)
After injecting and stirring the filtrate generated by the first pre-treatment step to have anionic surfactant and sodium hydroxide at pH 6 to 8, and then removing the sludge generated while stirring, heavy metals are stably adsorbed to the micelle of the anionic surfactant to form aggregates. After having a stationary group so as to cool and precipitate the agglomerates at 3 to 5 °C, the anionic surfactant is introduced to have an anionic surfactant: heavy metal molar ratio 6 to 10: 1,
In the filtration step (S300)
Filter using a filter press having a filter cloth size of 50 to 200 mesh and a pressure of 2 to 15 kgf/㎠,
The concentration step (S500)
A first concentration step of evaporating and concentrating the filtrate from which indium and gallium have been removed (S510); and
And a second concentration step (S520) of concentrating the evaporated concentrate by electrodialysis using a cation exchange resin having a film resistance of 0.5 to 3.5 Ω·cm 2;
Method for manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process.
delete According to claim 1,
The dissolving and neutralizing step (S200)
1 to 50 parts by weight of ammonium nitrate waste is added to 100 parts by weight of nitric acid (HNO3) and dissolved by stirring for 1 to 24 hours at a temperature of 60 to 90°C, and then neutralized to pH 7 to 8 by adding ammonia (NH3). Characterized by
Method for manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process.
According to claim 1,
The valuable metal extraction step (S400)
With respect to 100 parts by weight of the filtered ammonium nitrate waste filtrate, 20 to 200 parts by weight of a solvent alone or in combination of two or more of them in a trialkylphosphine-based solvent, an oxime-based solvent, or a phosphoric acid-based solvent is added and 30 at a rate of 500 to 1,500 rpm. It is characterized by obtaining a concentrate from which indium (In) and gallium (Ga) are extracted by stirring for 2 minutes to 2 hours.
Method for manufacturing fertilizer using ammonium nitrate waste generated in the metal oxide manufacturing process.
delete delete A urea-ammonium nitrate mixed fertilizer comprising ammonium nitrate obtained by the method for producing a fertilizer according to any one of claims 1, 3 and 4.

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