KR100430333B1 - Method for Preparing Sodium Nitrate Using Waste Nitric Acid - Google Patents
Method for Preparing Sodium Nitrate Using Waste Nitric Acid Download PDFInfo
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- KR100430333B1 KR100430333B1 KR10-2002-0024377A KR20020024377A KR100430333B1 KR 100430333 B1 KR100430333 B1 KR 100430333B1 KR 20020024377 A KR20020024377 A KR 20020024377A KR 100430333 B1 KR100430333 B1 KR 100430333B1
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D9/00—Nitrates of sodium, potassium or alkali metals in general
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- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
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Abstract
본 발명은 폐질산을 이용한 질산나트륨의 제조방법에 관한 것으로, 보다 상세하게는 (a) 중화조에 투입된 폐질산 수용액에 수산화나트륨 또는 탄산수소나트륨 수용액을 첨가하여 중화시키는 단계; (b) 여과기를 사용하여 상기 중화과정에서 침전된 불순물을 분리하는 단계; (c) 여과된 용액을 농축조로 투입하여 농축시키는 단계; (d) 농축된 용액을 석출조로 투입하여 질산나트륨을 석출시키는 단계; 및 (e) 여과기를 사용하여 석출된 질산나트륨을 분리하고, 이를 건조시켜 질산나트륨을 수득하는 단계를 포함하는 질산나트륨의 제조방법에 관한 것이며, 본 발명에 의해 폐질산 처리비용을 절감하고, 공업적으로 유용한 질산나트륨을 보다 저렴한 비용으로 생산할 수 있다.The present invention relates to a method for producing sodium nitrate using waste nitric acid, and more specifically, (a) neutralizing by adding sodium hydroxide or sodium bicarbonate aqueous solution to the waste nitric acid solution charged into the neutralization tank; (b) separating impurities precipitated in the neutralization process using a filter; (c) concentrating the filtered solution by introducing it into a concentration tank; (d) introducing the concentrated solution into a precipitation tank to precipitate sodium nitrate; And (e) separating the precipitated sodium nitrate using a filter, and drying the same to obtain sodium nitrate. The present invention relates to a method for producing sodium nitrate. Useful sodium nitrate can be produced at a lower cost.
Description
본 발명은 폐질산을 이용한 질산나트륨 제조방법에 관한 것으로, 보다 상세하게는 (a) 중화조에 투입된 폐질산 수용액에 수산화나트륨 또는 탄산수소나트륨 수용액을 첨가하여 중화시키는 단계; (b) 여과기를 사용하여 상기 중화과정에서 침전된 불순물을 분리하는 단계; (c) 여과된 용액을 농축조로 투입하여 농축시키는 단계; (d) 농축된 용액을 석출조로 투입하여 질산나트륨을 석출시키는 단계; 및 (e) 여과기를 사용하여 석출된 질산나트륨을 분리하고, 이를 건조시켜 질산나트륨을 수득하는 단계를 포함하는 질산나트륨의 제조방법에 관한 것이다.The present invention relates to a method for producing sodium nitrate using waste nitric acid, and more specifically, (a) neutralizing by adding sodium hydroxide or aqueous sodium bicarbonate solution to the waste nitric acid solution added to the neutralization tank; (b) separating impurities precipitated in the neutralization process using a filter; (c) concentrating the filtered solution by introducing it into a concentration tank; (d) introducing the concentrated solution into a precipitation tank to precipitate sodium nitrate; And (e) separating the precipitated sodium nitrate using a filter, and drying the same to obtain sodium nitrate.
질산나트륨은 질산소다(NaNO3)라고도 불리며, 무색의 결정으로 녹는점이 308℃이며, 비중이 2,257이고, 흡습성으로 물에 잘녹는 성질이 있다. 이러한 질산나트륨은 비료, 의약품, 화학약품 등으로 사용되고 있어 공업적으로 매우 유용한 물질이다.Sodium nitrate, also called sodium nitrate (NaNO 3 ), is a colorless crystal with a melting point of 308 ° C, a specific gravity of 2,257, and hygroscopic, so it is easily soluble in water. Sodium nitrate is used as a fertilizer, pharmaceuticals, chemicals, etc. is a very industrially useful material.
상기 질산나트륨은 예전에는 칠레의 태평양 연안에서 산출되는 칠레초석(硝石)을 물에 녹여 재결정시켜 정제하는 방법으로 제조되었으나, 최근에는 초석의 산출량이 적어져, 하기 반응식 1 또는 2에 표시된 바와 같이 질산에 수산화나트륨 또는 탄산나트륨을 가하는 방법으로 제조되고 있다.The sodium nitrate was previously prepared by dissolving and recrystallizing chilestone (산출 石) produced in the Pacific coast of Chile in water. It is manufactured by the method of adding sodium hydroxide or sodium carbonate to it.
한편 질산은 알루미늄 기판의 세척, 반도체 기판의 세척과 같은 공업적인 용도로 사용되고 있다. 한편 이때 발생되는 폐질산은 그 성질이 강한 산성임으로 인해 특별한 처리과정을 거친 후 폐기되어야 하므로 그 처리비용이 만만치 않다.On the other hand, nitric acid is used for industrial applications such as cleaning of aluminum substrates and cleaning of semiconductor substrates. On the other hand, waste nitric acid generated at this time has to be disposed of after a special treatment due to its strong acidity, so the treatment cost is not significant.
본 발명자들은 이러한 폐질산을 이용하여 공업적으로 유용한 질산나트륨을제조하는 방법을 제공하여 폐질산의 처리비용을 절감함과 동시에 질산나트륨을 저렴하게 생산하는 방법을 제공함을 목적으로 한다.The inventors of the present invention aim to provide a method for producing industrially useful sodium nitrate using such waste nitric acid to reduce the treatment cost of waste nitric acid and at the same time to produce sodium nitrate at low cost.
즉, 본 발명은 (a) 알루미늄 및 반도체 기판의 세척 폐액인 폐질산 수용액을 중화조에 투입하고 수산화나트륨 또는 탄산수소나트륨 수용액을 첨가하여 중화시킨 다음, 고분자응집제를 첨가하여 불순물을 응집시키는 단계, (b) 여과기를 사용하여 상기 응집된 침전된 불순물을 분리·제거하는 단계, (c) 상기 여과된 용액을 농축조에 투입하여 압력 약 0.0681kg/cm2및 온도 약 104℃에서 농축시키는 단계, (d) 상기 농축된 용액을 석출조에 투입한 다음, 40~50℃로 냉각시켜 질산나트륨을 석출시키는 단계, (e) 여과기를 사용하여 상기 석출된 질산나트륨을 분리·회수한 다음, 이를 건조시켜 질산나트륨을 수득하는 단계 및 (f) 상기 (e) 단계에서 여과된 여액을 (c)단계로 재순환시키는 단계를 포함하는 알루미늄 및 반도체 기판의 세척 폐액으로부터 질산나트륨을 제조하는 방법에 관한 것이다.That is, the present invention comprises the steps of (a) adding an aqueous waste nitric acid solution, which is a cleaning waste liquid of aluminum and a semiconductor substrate, to a neutralization tank, neutralizing by adding an aqueous sodium hydroxide or sodium hydrogen carbonate solution, and then aggregating impurities by adding a polymer coagulant, ( b) separating and removing the aggregated precipitated impurities using a filter, (c) adding the filtered solution to a concentration tank and concentrating at a pressure of about 0.0681 kg / cm 2 and a temperature of about 104 ° C., (d ) The concentrated solution was added to a precipitation tank, and then cooled to 40-50 ° C. to precipitate sodium nitrate. (E) The precipitated sodium nitrate was separated and recovered using a filter, and then dried to obtain sodium nitrate. Removing sodium nitrate from the washing waste liquid of the aluminum and semiconductor substrates, comprising the steps of: (c) recycling the filtrate filtered in step (e) to step (c). It relates to a method.
도 1은 본 발명의 일시예에 의해 질산나트륨이 제조되는 공정을 나타낸 흐름도이다.1 is a flow chart showing a process for producing sodium nitrate by one embodiment of the present invention.
이하에서 본 발명을 보다 상세하게 설명한다.The present invention will be described in more detail below.
먼저 폐질산 수용액을 중화조에 투입한 후, 수산화나트륨 또는 탄산수소나트륨 수용액을 이용하여 pH가 7이 되도록 조절해 준다. 이러한 중화과정 중에 불순물 로서 수산화알루미늄 등의 성분이 침전된다. 이때 침전효율을 높이기 위해서 녹말류, 폴리아크릴아미드 또는 그 유도체와 같은 고분자 응집제를 소량 첨가하여도 좋다.First, the aqueous waste nitric acid solution is added to the neutralization tank, and then adjusted to pH 7 using sodium hydroxide or sodium bicarbonate aqueous solution. During this neutralization process, components such as aluminum hydroxide precipitate as impurities. At this time, a small amount of a polymer flocculant such as starch, polyacrylamide or derivatives thereof may be added to increase the precipitation efficiency.
상기 침전된 불순물은 여과기를 사용하여 걸려낸다. 이때 분리된 침전물은 그 주성분이 수산화알루미늄인 경우 이를 건조하는 과정을 거쳐서 공업원료로서 재사용할 수 있다.The precipitated impurities are caught using a filter. At this time, the separated precipitate can be reused as an industrial raw material through the drying process if the main component is aluminum hydroxide.
다음으로 상기 여과기를 통과한 여액을 농축조(Thickner)로 이송하여 열에 의하여 농축시킨다. 이때 진공펌프를 이용하여 농축조의 압력을 낮추는 경우 수증기의 비점이 낮아져 농축효율이 더욱 높아짐으로 바람직하다.Next, the filtrate passing through the filter is transferred to a thickener and concentrated by heat. At this time, when the pressure of the concentration tank is lowered by using a vacuum pump, the boiling point of water vapor is lowered, and thus the concentration efficiency is higher.
일정 수준으로 농축된 질산나트륨 수용액을 석출기(Crystallizer)로 이송하여 온도에 따라 용해도 차이를 이용하여 질산나트륨을 석출시킨다.The sodium nitrate solution concentrated to a certain level is transferred to a crystallizer to precipitate sodium nitrate using a difference in solubility according to temperature.
용해도는 용매 100g속에 최대로 녹을 수 있는 용질의 g수를 말하는데, 일반적으로 물질의 용해도는 온도의 변화에 따라서 달라지며, 고체의 용해도는 온도가 상승함에 따라 증가하는 경우가 대부분이다. 물을 용매로 하였을 때, 온도에 따른 질산나트륨의 용해도는 하기 표 1에 표시된 바와 같다.Solubility refers to the maximum number of solutes that can be dissolved in 100 g of solvent. In general, the solubility of a substance varies with temperature, and the solubility of a solid is usually increased with increasing temperature. When water is used as a solvent, the solubility of sodium nitrate according to temperature is shown in Table 1 below.
상기에서 알 수 있듯이 질산나트륨의 용해도는 온도가 감소함에 따라 급격하게 줄어든다. 따라서 농축조에서 열에 의해 가열, 농축된 수산화나트륨 수용액은 석출기에서 온도가 갑자기 낮아지면 질산나트륨의 온도에 따른 용해도 차이에 의해 질산나트륨이 석출되는 현상이 발생된다.As can be seen above, the solubility of sodium nitrate decreases rapidly as the temperature decreases. Therefore, when the sodium hydroxide aqueous solution heated and concentrated by heat in the concentration tank suddenly lowers in the precipitater, sodium nitrate precipitates due to a difference in solubility according to the temperature of sodium nitrate.
이렇게 석출된 질산나트륨은 여과기를 사용하여 분리수거되며 이를 건조시켜 공업적으로 사용가능한 질산나트륨 원료를 수득할 수 있다. 이때 여과기를 통과한 여액은 농축조로 재순환되어 질산나트륨의 제조에 이용된다.The sodium nitrate thus precipitated is separated and collected using a filter and dried to obtain an industrially usable sodium nitrate raw material. At this time, the filtrate passed through the filter is recycled to the concentration tank is used for the production of sodium nitrate.
상기와 같은 방법으로 제조되는 질산나트륨의 순도는 99% 이상 이며, 일반적 공업용도에 무리없이 적용될 수 있다.The purity of sodium nitrate prepared by the above method is 99% or more, and can be applied to general industrial use without difficulty.
이하에서 실시예를 통하여 본 발명을 보다 상세하게 설명하고자 하나 하기의 실시예는 설명의 목적을 위한 것으로 본 발명을 제한하고자 하는 것은 아니다.Hereinafter, one embodiment of the present invention will be described in more detail with reference to the following examples, which are intended for purposes of explanation and are not intended to limit the present invention.
실시예Example
도 1은 본 실시예에 따른 질산나트륨의 제조공정을 나타내는 공정흐름도이다.1 is a process flow diagram showing a manufacturing process of sodium nitrate according to the present embodiment.
본 실시예에서 폐질산으로는 알루미늄 기판의 세척에 사용되었던 것으로, 질산의 함량이 약 15%이고, 알루미늄의 함량이 약 1%인 것을 사용하였다.In this embodiment, the waste nitric acid was used to wash the aluminum substrate, and the nitric acid content was about 15% and the aluminum content was about 1%.
우선 15% 농도의 폐질산 수용액을 중화조(1)에 투입한 후 50 % 농도의 가성소다 수용액을 투입하여 pH가 7이 되도록 하였다. 이때 수산화알루미늄의 침전을 돕기 위해 폴리아크릴아미드를 응집제로 첨가하였다. 침전된 수산화알루미늄은 여과기(Belt press: 2)를 사용하여 걸러내었다.First, a 15% aqueous waste nitric acid solution was added to the neutralization tank 1, and a 50% aqueous caustic soda solution was added thereto so as to have a pH of 7. At this time, polyacrylamide was added as a flocculant to aid precipitation of aluminum hydroxide. Precipitated aluminum hydroxide was filtered off using a filter (Belt press: 2).
도 1에서 표시된 바와 같이 여과액을 완충탱크(cushion tank: 3), 질산나트륨 저장탱크(4)를 거쳐 농축조(5)로 이송하였다. 농축조(5)에서는 진공펌프(8)를 이용하여 압력을 0.068kg/cm2으로 조절하여 수용액의 온도가 104℃가 될때까지 서서히 가열하여 질산나트륨 수용액을 농축하였다. 이때 기화된 수증기는 냉각기(9)로 이송되어 응축된 후 응축탱크(10)에 저장되었다.As shown in FIG. 1, the filtrate was transferred to a concentration tank 5 through a cushion tank 3 and a sodium nitrate storage tank 4. In the concentration tank (5) by using a vacuum pump (8) to adjust the pressure to 0.068kg / cm 2 and slowly heated until the temperature of the aqueous solution to 104 ℃ to concentrate the aqueous solution of sodium nitrate. At this time, the vaporized water vapor was transferred to the cooler 9 to condense and stored in the condensation tank 10.
농축조(5)에서 농축된 수용액을 석출조(6)로 이송하여 40∼50℃까지 냉각시켜 질산나트륨을 석출시키고 석출된 질산나트륨을 여과기(Vertical filter: 7)를 사용하여 분리수거하였다. 분리수거된 질산나트륨을 건조시켜 순도 99.1%의 공업용 질산나트륨 원료를 생산하였다. 한편 여과기(7)를 통과한 여과액은 완충탱크(3)로 재순환되어 질산나트륨의 제조에 재사용되었다.The aqueous solution concentrated in the concentration tank 5 was transferred to the precipitation tank 6, cooled to 40-50 ° C. to precipitate sodium nitrate, and the precipitated sodium nitrate was separated and collected using a filter (Vertical filter 7). Separately collected sodium nitrate was dried to produce an industrial sodium nitrate raw material having a purity of 99.1%. Meanwhile, the filtrate passing through the filter 7 was recycled to the buffer tank 3 and reused for the production of sodium nitrate.
본 발명에서는 폐질산을 이용하여 질산나트륨을 제조하기 때문에, 폐질산 처리비용을 절감하고, 공업적으로 유용한 질산나트륨을 보다 저렴한 비용으로 생산할 수 있게 되었다.In the present invention, since sodium nitrate is produced using waste nitric acid, the waste nitric acid treatment cost can be reduced, and industrially useful sodium nitrate can be produced at a lower cost.
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KR101204177B1 (en) | 2011-10-12 | 2012-11-22 | (주)새빗켐 | Method for preparing potassium nitrate using a potassium hydroxide waste solution containing silicon compound and a waste solution containing nitric acid |
CN105621459A (en) * | 2016-03-30 | 2016-06-01 | 青海盐湖工业股份有限公司 | Sodium nitrate preparation method |
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CN105016364A (en) * | 2015-07-03 | 2015-11-04 | 柳州市亿瑞物资有限责任公司 | Sodium nitrate recovery method |
CN107934997B (en) * | 2017-12-18 | 2019-11-22 | 中核二七二铀业有限责任公司 | A method of sodium nitrate is produced using nuclear leve zirconium dioxide production waste discharge |
CN115253979A (en) * | 2022-08-23 | 2022-11-01 | 太仓沪试试剂有限公司 | Open type enamel reaction kettle and method for preparing sodium nitrate by adopting same |
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JPS5238493A (en) * | 1975-09-23 | 1977-03-25 | Mitsubishi Chem Ind Ltd | Production of powder or grain of sodium nitrite or sodium nitrate |
US4995950A (en) * | 1987-09-04 | 1991-02-26 | Basf Aktiengesellschaft | Preparation of alkali metal nitrates |
KR100201179B1 (en) * | 1994-05-20 | 1999-06-15 | 들로 다니엘 | Process for valorizing a liquid acid effluent containing heavy metals |
WO1997003284A1 (en) * | 1995-07-12 | 1997-01-30 | Societe Hispano Suiza | Turbofan engine thrust reverser with asymmetrical doors |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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KR101204177B1 (en) | 2011-10-12 | 2012-11-22 | (주)새빗켐 | Method for preparing potassium nitrate using a potassium hydroxide waste solution containing silicon compound and a waste solution containing nitric acid |
CN105621459A (en) * | 2016-03-30 | 2016-06-01 | 青海盐湖工业股份有限公司 | Sodium nitrate preparation method |
CN105621459B (en) * | 2016-03-30 | 2017-11-21 | 青海盐湖工业股份有限公司 | A kind of preparation method of sodium nitrate |
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