[go: up one dir, main page]

WO2025226250A1 - Procédé de récupération de nitrate d'argent - Google Patents

Procédé de récupération de nitrate d'argent

Info

Publication number
WO2025226250A1
WO2025226250A1 PCT/TR2025/050387 TR2025050387W WO2025226250A1 WO 2025226250 A1 WO2025226250 A1 WO 2025226250A1 TR 2025050387 W TR2025050387 W TR 2025050387W WO 2025226250 A1 WO2025226250 A1 WO 2025226250A1
Authority
WO
WIPO (PCT)
Prior art keywords
silver
recovery method
nitrate
reactor tank
solution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/TR2025/050387
Other languages
English (en)
Inventor
Semin CANBAZOGLU
Timucin BALKAN
Emin Burak IZMIRLIOGLU
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Turkiye Sise Ve Cam Fabrikalari AS
Original Assignee
Turkiye Sise Ve Cam Fabrikalari AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Turkiye Sise Ve Cam Fabrikalari AS filed Critical Turkiye Sise Ve Cam Fabrikalari AS
Publication of WO2025226250A1 publication Critical patent/WO2025226250A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G5/00—Compounds of silver

Definitions

  • the present invention relates to the recovery, in the form of silver nitrate, of the silver sludge that arises on a production line.
  • the silver chemical product silver nitrate is the raw material and the basis for other high-value-added silver products. It is widely used in many areas such as mirror manufacture, medicine, electroplating and ultra-fine silver powder.
  • the most common route to prepare high-purity silver nitrate is a reaction process that comprises adding nitric acid to dissolve silver followed by impurity removal and the successive operations of filtration, evaporation and concentration, crystallisation, centrifuging, drying and packaging to obtain silver.
  • Adding nitric acid to dissolve silver generates large amounts of nitrogen-oxide exhaust gas (NOx) during the reaction.
  • NOx nitrogen-oxide exhaust gas
  • Nitrogen oxides mainly NO and NO 2 , are an important cause of photochemical smog and acid rain and pose a serious threat to human health and the ecological environment.
  • EP0568259 A1 concerns a method for preparing silver nitrate. It discloses a process for producing a silver-nitrate solution without releasing nitrogen oxides, in which metallic silver is reacted with nitric acid and from 20 % to 30 % excess hydrogen peroxide over the stoichiometric requirement.
  • An object of the invention is to provide an environmentally friendly silver-nitrate recovery method for recycling silver sludge.
  • the invention relates to a silver-nitrate recovery method that comprises the process steps of preparing a nitric-acid solution in a reactor tank and feeding silver sludge into the prepared acid solution to obtain an intermediate product.
  • the silver-nitrate recovery method further comprises introducing N 2 onto the intermediate product, sweeping the resulting NOx gases with the introduced N 2 and reacting them with H 2 O 2 so as to eliminate them, and collecting the silver nitrate formed in a vessel.
  • most of the nitrogen-oxide waste gas generated in the reaction between the silver sludge and nitric acid is reconverted into nitric acid with hydrogen peroxide for reuse, providing an environment-friendly solution.
  • the reactor tank is temperature-controlled and its temperature is maintained in the range of 55 °C to 95 °C, whereby the reaction temperature can be controlled via the reactor tank and kept constant at the temperature suitable for the reaction.
  • the initial silver-sludge concentration is in the range of 50 to 600 gpL depending on the desired concentration of the silver-nitrate solution. Adjusting the initial concentration can limit unnecessary waste generation and reduce environmental harm; it can also help make recycling processes more efficient when necessary.
  • the initial amount of nitric acid is between 15 L and 75 L. Determining the nitric-acid usage in this way enables the formation of harmful by-products such as NOx to be identified and eliminated and reduces the quantity of harmful gases emitted to the atmosphere.
  • the amount of nitric acid recovered with hydrogen peroxide is between 7 L and 40 L, thereby recovering nitrogen-oxide gases as nitric acid and providing an environmentally beneficial recovery method.
  • nitrogen gas is introduced at a rate of 0.5 - 2.5 L min -1 . This allows the amount of nitrogen introduced into the reactor tank to be regulated according to the amount of nitrogen-oxide gas produced in the tank.
  • water vapour released in the reactor tank is collected in a collection vessel. Collecting the water vapour leaving the reactor reduces waste generation and can potentially lower treatment or waste-management costs.
  • the silver-nitrate solution is passed through a filter to collect impurities produced in the reactor as a result of the reaction, thereby removing undesirable impurities from the silver-nitrate solution and increasing the purity of the final product.
  • the silver-nitrate solution is sent to a crystallisation unit for purification. Crystallisation ensures that the silver nitrate is obtained at a high degree of purity.
  • the silver-nitrate crystals obtained are purified so that their purity is in the 95 % - 100 % range.
  • High-purity silver nitrate yields high-quality end products in the specific field in which it is used.
  • the high purity of the silver nitrate used directly affects the quality of the final product: because the silver, which converts to the metallic form after application, contains fewer impurities, it is less prone to oxidation, and the product quality therefore depends on the silver nitrate being sufficiently pure.
  • a nitric-acid solution is prepared in a reactor tank.
  • the prepared nitric-acid solution is fed with silver sludge into a temperature-controlled jacketed steel reactor.
  • the desired Ag concentration of the solution is controlled by the nitric-acid concentration in the feed.
  • Nitrogen gas (N 2 ) is supplied to the reactor tank to sweep the NOx gases generated therein.
  • the resulting NOx gases are washed and eliminated by reaction with hydrogen peroxide.
  • the hydrogen peroxide is in liquid form in a glass-packed column.
  • the best NOx-removal results are obtained when 20 % - 30 % more hydrogen peroxide than the stoichiometric requirement is used.
  • a silver-nitrate solution free of free acid can be obtained without generating any trace of NOx in the process.
  • the water volatilised during the reaction is condensed and collected in a condenser and a collection vessel.
  • a filter press is used to collect the impurities originating from the mirror line that did not participate in the reaction, and the AgNO 3 aqueous solution is accumulated in a collection vessel and sent to the crystallisation unit for purification.
  • Silver-nitrate crystals obtained in the crystallisation unit are ensured to have a purity of 98 % - 100 %.
  • HNO 3 solution 15 L of HNO 3 solution is retained in the reactor tank.
  • the reaction is started by feeding 500 gpL of silver sludge — depending on the desired concentration of the silver-nitrate solution — into the reactor tank.
  • Nitrogen gas is introduced into the reactor tank at 1 .5 L min -1 to sweep the NOx gases.
  • H 2 O 2 reacts with NOx, washing and eliminating the gases.
  • 750 -800 g of silver-nitrate solid is obtained.
  • the test results of the mirror produced by the recovery method under a D65 light source show a reflection value L of 97.18, a colour value a of -1 .8058 and a colour value b of 2.1433.
  • the daylight value is 93 % and the solar-energy value is 84.1 %.
  • Paint-thickness testing determined that the mirror produced by the recovery method had a paint thickness of 56 pm.
  • Pull-off testing established that the mirror detached in red paint at a failure pressure of 4.22 - 3.87 MPa.
  • Pendulum testing of the mirror produced by the recovery method found the swing time to be 179 s in 179 swings. When the mirror produced by the recovery method was subjected to a 20-day humidity test it was deemed suitable for use.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Treatment Of Water By Oxidation Or Reduction (AREA)

Abstract

L'invention concerne un procédé de récupération de nitrate d'argent comprenant les étapes de traitement consistant à préparer une solution d'acide nitrique dans une cuve de réacteur et à introduire des boues d'argent dans la solution acide préparée pour obtenir un produit intermédiaire. Le procédé de récupération de nitrate d'argent comprend en outre l'introduction de N2 sur le produit intermédiaire, le balayage des gaz NOx obtenus avec le N2 introduit et leur réaction avec H2O2 de façon à les éliminer, et la collecte du nitrate d'argent formé dans une cuve.
PCT/TR2025/050387 2024-04-22 2025-04-22 Procédé de récupération de nitrate d'argent Pending WO2025226250A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
TR2024/004821 2024-04-22
TR2024/004821A TR2024004821A1 (tr) 2024-04-22 2024-04-22 Bi̇r gümüş ni̇trat geri̇ kazanim metodu

Publications (1)

Publication Number Publication Date
WO2025226250A1 true WO2025226250A1 (fr) 2025-10-30

Family

ID=97490798

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/TR2025/050387 Pending WO2025226250A1 (fr) 2024-04-22 2025-04-22 Procédé de récupération de nitrate d'argent

Country Status (2)

Country Link
TR (1) TR2024004821A1 (fr)
WO (1) WO2025226250A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5000928A (en) * 1986-03-17 1991-03-19 Eastman Kodak Company Preparation of ultra-pure silver nitrate
EP0568259A1 (fr) * 1992-04-30 1993-11-03 Noranda Inc. Procédé de fabrication d'une solution de nitrate d'argent
US5364500A (en) * 1991-02-04 1994-11-15 Eastman Kodak Company Process for removing nitrites from a silver nitrate solution
EP0733593A1 (fr) * 1993-12-28 1996-09-25 Eastman Kodak Company Procédé continu pour éliminer les impurétés de nitrate d'argent brut

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5000928A (en) * 1986-03-17 1991-03-19 Eastman Kodak Company Preparation of ultra-pure silver nitrate
US5364500A (en) * 1991-02-04 1994-11-15 Eastman Kodak Company Process for removing nitrites from a silver nitrate solution
EP0568259A1 (fr) * 1992-04-30 1993-11-03 Noranda Inc. Procédé de fabrication d'une solution de nitrate d'argent
EP0733593A1 (fr) * 1993-12-28 1996-09-25 Eastman Kodak Company Procédé continu pour éliminer les impurétés de nitrate d'argent brut

Also Published As

Publication number Publication date
TR2024004821A1 (tr) 2025-11-21

Similar Documents

Publication Publication Date Title
CN1082935C (zh) 溶解和提纯五氧化二钽的方法
JP2019131448A (ja) 水酸化リチウムの製造方法
EP0154826B1 (fr) Procédé de préparation de silane
CN112897600B (zh) 一种硫酸四氨钯（ⅱ）的制备方法
WO2025226250A1 (fr) Procédé de récupération de nitrate d'argent
JPH06157008A (ja) 沃素及び／又は無機沃素化合物を含有する廃液から沃素を回収する方法
RU2424187C1 (ru) Способ получения высокочистого фторида бария
RU2424188C1 (ru) Способ получения высокочистого фторида кальция
JP2011522127A (ja) 純粋な過レニウム酸アンモニウムの製造方法
CN110205500B (zh) 一种还原金粉中杂质的脱除方法
RU2330811C2 (ru) Способ получения высокочистого фторида лития
JPH04271840A (ja) 触媒回収方法
KR840000518B1 (ko) 2,6-디클로로-4-니트로 아닐린의 제조방법
US5182092A (en) Hydroxylammonium nitrate process
JPS61195935A (ja) 滅菌用浄化剤の製造方法
CA1230463A (fr) Productions de solutions extra-pures d'hydrosulfites de metal alcalin
CN109369447B (zh) 一种3-（2,2,2-三甲基肼）丙酸盐二水合物的制备技术的改进方法
JPH01115820A (ja) 水酸化ニオブまたは水酸化タンタルの製造方法
SU1664739A1 (ru) Способ получени иодидов и иодатов металлов
US3006724A (en) Preparation of aluminum hydroxy fluoride
US3954453A (en) Recovery of copper from ammoniacal copper sulfate solution
JP4225523B2 (ja) 亜硝酸亜鉛水溶液およびその製造方法
JP3167516B2 (ja) タウリン精製に使用したアルコールの回収方法
CN117585687B (zh) 镀金废料合成氰化金钾的方法
JP7506383B1 (ja) 光学ガラス廃材からレアメタルを回収する方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 25794667

Country of ref document: EP

Kind code of ref document: A1