Absorption of Nitrogen Dioxide into Water, Sulfuric Acid, Sodium Hydroxide, and Alkaline Sodium Sulfite Aqueous Solutions

1977 ◽  
Vol 16 (1) ◽  
pp. 163-169 ◽  
Author(s):  
Yohji Kameoka ◽  
Robert L. Pigford
Keyword(s):  
Sulfuric Acid ◽  
Aqueous Solutions ◽  
Nitrogen Dioxide ◽  
Sodium Hydroxide ◽  
Sodium Sulfite

scholarly journals Obtaining selenium concentrate from the slime of the sulfuric acid workshop of the Balkhash copper plant and extracting selenium from it into solution

2020 ◽  
Vol 4 (315) ◽  
pp. 11-24
Author(s):  
A. N. Zagorodnyaya ◽  
◽  
A. S. Sharipova ◽  
X. A. Linnik ◽  
G. S. Ruzakhunova ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sodium Hydroxide ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Sodium Sulfite ◽  
Sodium Hydroxide Solution ◽  
Colloidal Suspension ◽  
Copper Smelting ◽  
Elemental Selenium ◽  
Mercury Selenide

The article presents the results of large-scale laboratory tests of obtaining selenium concentrate from the slime of the sulfuric acid workshop (hereinafter: slime) of the Balkhash copper smelting plant and the extraction of selenium from it into solution. This slime, in contrast to similar slime from non-ferrous metallurgy plants, significantly differs in chemical and material compositions, especially in the selenium content (4.6 - 12.5 wt.%). Involving it in the production sphere will increase the production of selenium by more than 20% from that obtained by the plant from copper electrolyte slime. The slime is washed with water to remove sulfuric acid, dried at 105 ° C. Selenium concentrate was obtained by sequential leaching of slime with solutions of sodium carbonate and nitric acid, selenium from the concentrate was leached with solutions of sodium sulfite (atmospheric pressure) and sodium hydroxide (high pressure, autoclave leaching). Slime, concentrate, cakes, precipitates isolated from solutions, and solutions were analyzed using modern devices of a new generation: An Optima-8300 inductively coupled plasma spectrometer, an Axios X-ray fluorescence spectrometer, an Optima 2000 atomic emission spectroscope, a D8 Advance diffractometer, a D8 Advance infrared spectrometer Avatar 370. From the slime containing, wt. %: 51.2 Pb, 12.5 Se, 3.21 Hg and other elements, a selenium concentrate was obtained with the composition, wt. %: 0.41 Pb, 59.16 Se, 15.4 Hg. The technological indicators for obtaining a concentrate are given, %: concentrate yield - 20.74, Pb recovery - 0.81, Se - 98.23, Hg - 99.50. According to XRD and IR spectroscopy, the concentrate contains elemental selenium and mercury selenide from 10 selenium substances contained in the slime (given in the article). The extraction of selenium from the concentrate into the solution was, %: sodium sulfite - 76.84, sodium hydroxide - 89.65. The pulp from opening the concentrate with sodium hydroxide solution was filtered very poorly. The filtrates contained a colloidal suspension, which could not be filtered off either under vacuum or centrifugation. Therefore, to determine the qualitative and material composition of the filtrates, salts were obtained by evaporating a certain and then neutralized volume to dryness. It was found that only elemental selenium is leached from the concentrate by solutions of both reagents, while mercury selenide remains in the cakes. Moreover, over time, elemental selenium partially precipitated again from selenium-containing sodium sulfite solutions; the salts contain only elemental selenium. An explanation is given for the transition of soluble selenium salts to its elemental state. Despite the higher recovery of selenium from the concentrate by leaching in autoclaves, taking into account the equipment, the complexity of its maintenance, filtration of the pulp and the chemical composition of the filtrate, it is preferable to use the method of leaching with sodium sulfite.

scholarly journals Absorption of H2S with sodium hydroxide from the black liquid of sulfate pulp production

2019 ◽  
Author(s):  
О.В. Федорова ◽  
В.Г. Казаков ◽  
К.О. Субботина
Keyword(s):  
Hydrogen Sulfide ◽  
Sulfuric Acid ◽  
Aqueous Solutions ◽  
Sodium Hydroxide ◽  
Sodium Sulfide ◽  
Black Liquor ◽  
White Liquor ◽  
Sulfate Pulp ◽  
Sulfur Containing ◽  
Sulphate Pulp

При обработке черного щелока сульфат-целлюлозного производства серной кислотой (с целью частичного или полного высаждения сульфатного лигнина) происходит выделение сероводорода и других серосодержащих газов. Рассмотрен процесс поглощения этих газов путем абсорбции водным раствором гидроксида натрия. Процесс подкисления черного щелока серной кислотой сопровождается выделением сероводорода, который должен подвергаться абсорбции. Промышленные методы получения сульфатного лигнина предусматривают применение абсорбции сероводорода водными растворами гидроксида натрия. В качестве абсорбентов при поглощении серосодержащих газов применяют растворы щелочи или воду в зависимости от состава сероводородных газов и дальнейшего использования продуктов абсорбции. Водные растворы гидроксида натрия применяются для абсорбции в тех случаях, когда обработке подвергаются значительные объемы газов, содержащих преимущественно сероводород. При этом в процессе абсорбции получается раствор сульфида натрия. В случае подкисления черного щелока серной кислотой абсорбции подвергается сероводород, который содержит и другие примеси. Для того чтобы абсорбция сероводорода гидроксидом натрия прошла с образованием конечного продукта сульфида натрия, необходимо использовать определенную концентрацию щелочи. Для достижения необходимого результата использовался симплекс-метод по целочисленной матрице, который позволил выбрать оптимальные параметры проведения процесса абсорбции сероводорода гидроксидом натрия. В результате получен раствор белого щелока с высокой сульфидностью, что является положительной характеристикой процесса варки сульфатной целлюлозы, так как уменьшает продолжительность варки до определенной степени провара, облегчает процесс делигнификации, а также увеличивает выход целлюлозы. Это позволяет уменьшить расход реагентов при приготовлении белого щелока, подаваемого на варку технологической щепы. По предложенному методу осаждение лигноуглеводного комплекса из черного щелока проводят без применения содорегенерационных котлов, где процесс получения белого щелока связан с получением плава щелочей и последующим получением из него зеленого щелока, с дальнейшей регенерацией белого щелока, используемого для варки сульфатной целлюлозы. В результате установлена принципиальная возможность абсорбции сероводорода раствором гидроксида с выполнением требований, предъявляемых к белому щелоку. While black liquor from sulfate pulp process treatment with sulfuric acid (for partial or full sulfate lignin precipitation) emission of hydrosulfide and other sulfur containing gasses happens. It is reviewed process of the gasses absorption by sodium hydroxide solution. The process of acidification of black liquor with sulfuric acid is accompanied by the release of hydrogen sulfide, which must undergo absorption. Industrial methods for producing sulphate lignin involve the use of hydrogen sulfide absorption by aqueous solutions of sodium hydroxide. Alkali solutions or water are used as absorbents for absorption of sulfur-containing gases, depending on the composition of hydrogen sulfide gases and the further use of absorption products. Aqueous solutions of sodium hydroxide are used for absorption in cases where significant volumes of gases containing predominantly hydrogen sulfide are processed. In the process of absorption is obtained a solution of sodium sulfide. In the case of acidification of black liquor with sulfuric acid, hydrogen sulfide is subjected to absorption, which contains other impurities. In order for the absorption of hydrogen sulfide by sodium hydroxide to form the final product of sodium sulfide, it is necessary to use a certain concentration of alkali. To achieve the required results, a simplex method was used for the integer matrix, which allows choosing the optimal parameters for the process of hydrogen sulfide absorption by sodium hydroxide. As a result of the experiment, a solution of white liquor with high sulfidity is obtained. which is a positive characteristic of the sulphate pulp boiling process, as it reduces the cooking time to a certain degree of penetration, facilitates the delignification process, and also increases the cellulose yield. This allows reducing the consumption of reagents in the preparation of white liquor fed to the cooking chips. According to the proposed method, the precipitation of the black liquor lignohydrocarbon complex is carried out without the use of soda recovery boilers, where the process of obtaining white liquor is associated with obtaining alkaline water and subsequent production of green liquor from it, with further regeneration of white liquor used for cooking sulphate pulp. As a result of the experiment, the principal possibility of hydrogen sulfide absorption by a hydroxide solution was established with the fulfillment of the requirements for white liquor.

Characteristics of Sonoluminescing Bubbles in Aqueous Solutions of Sulfuric Acid

2006 ◽  
Vol 75 (11) ◽  
pp. 114705 ◽  
Author(s):  
Ki Young Kim ◽  
Ki-Taek Byun ◽  
Ho-Young Kwak
Keyword(s):  
Sulfuric Acid ◽  
Aqueous Solutions

The Influence of Heat and Two Stages Precipitation in the Process of Natural Polymer Purification from the Byproduct of Bioethanol Process Base on Empty Palm Fruit Bunch

2015 ◽  
Vol 1123 ◽  
pp. 177-181
Author(s):  
Achmad Hanafi ◽  
Harry Budiman ◽  
Fauzan Aulia
Keyword(s):  
Sulfuric Acid ◽  
Sodium Hydroxide ◽  
Room Temperature ◽  
Black Liquor ◽  
Ash Content ◽  
Natural Polymer ◽  
Palm Fruit ◽  
Second Stage ◽  
Direct Precipitation ◽  
Two Stages

The biopolymer material, lignin, was recovered from the black liquor by acidification of the black liquor using sulfuric acid. Several purification techniques were carried out to produce the high purity of lignin such as gradual precipitation of lignin from black liquor (first stage: precipitation at pH 7, second stage: precipitation at pH 2) and the diluting of crude lignin by sodium hydroxide then followed by re-precipitation at different temperature. Subsequently, the impurities of lignin product resulted from each purification techniques was determined as ash content that analyzed using temperature program furnace; and the content of lignin was investigated using spectrophotometer UV-Vis. The result showed that the content of lignin of material produced from gradual precipitation was approximately 77.6%. It was higher than the content of lignin about 3.4% of material produced from direct precipitation to pH 2. In addition, the elevating of temperature from 40 to 60°C was no considerably affect to the content of lignin in precipitate produced from re-precipitation of crude lignin solution in sodium hydroxide. Nonetheless, the content of lignin of precipitate improved 15% when the temperature of re-precipitation of crude lignin solution in sodium hydroxide was raised from room temperature to 40-60°C.

scholarly journals PEMBUATAN MIKROKRISTALIN SELULOSA ROTAN MANAU (Calamus manan sp.) SERTA KARAKTERISASINYA

2014 ◽  
Vol 4 (02) ◽  
Author(s):  
Steven . ◽  
Mardiyati . ◽  
R. Suratman
Keyword(s):  
Sulfuric Acid ◽  
Natural Resources ◽  
Acid Hydrolysis ◽  
Sodium Hydroxide ◽  
Microcrystalline Cellulose ◽  
High Cellulose

Rattan is one of natural resources of Indonesia which contains 30%-40% cellulose. Its high cellulose contents makes it very potential as a source of microcrystalline cellulose (MCC). In this research, manau rattan was characterized by using the Chesson methods. Microcrystalline cellulose was prepared by using two methods, i.e. alkalization and acid hydrolysis. Alkalization was performed by soaking manau rattan powder into sodium hydroxide 17,5% for 8 hours. Acid hydrolysis was prepared by using sulfuric acid at a concentration of 0.1 M; 0.3 M; and 0.5 M for 4, 6, 8, and 10 hours. The crystallinity of MCC was quantitatively measured by XRD and qualitatively measured by using FTIR. In this research, we have successfully made microcrystalline cellulose from manau rattan. The highest crystallinity MCC of 72.42% was obtained from acid hydrolysis with 0.5 M for 10 hours. The crystallinity of the MCC product increases with concentration and hydrolysis time.Keywords: acid hydrolisis, alkalization, cellulose, manau rattan, MCCABSTRAKRotan merupakan salah satu kekayaan hayati Indonesia yang mengisi sepuluh persen hutan di Indonesia yang memiliki kadar selulosa mencapai 30-40%. Kadar selulosa yang cukup tinggi membuat rotan sangat berpotensi untuk dimanfaatkan sebagai bahan baku mikrokristalin selulosa (MCC). Rotan manau dikarakterisasi menggunakan metode Chesson. Pembuatan mikrokristalin selulosa terdiri atas dua tahap, yaitu alkalisasi dan hidrolisi asam. Tahap alkalisasi dilakukan dengan merendam rotan di dalam larutan NaOH 17,5% selama 8 jam. Tahap hidrolisis asam dilakukan dengan menggunakan asam sulfat pada berbagai konsentrasi, yakni 0,1; 0,3 dan 0,5 M selama 4, 6, 8, dan 10 jam. Kristalinitas dari MCC yang dihasilkan diukur dengan menggunakan XRD. Untuk mengetahui komposisi kimia serta kristalinitas MCC secara kualitatif, telah dilakukan karakterisasi dengan menggunakan FTIR. Pada penelitian ini, telah berhasil dibuat MCC yang bersumber dari rotan manau. Kristalinitas MCC tertinggi dihasilkan dengan perlakuan hidrolisis asam dengan konsentrasi 0,5 M selama 10 jam, yaitu sebesar 72,42%. Seiring dengan peningkatan konsentrasi serta waktu hidrolisis, kristalinitas MCC yang dihasilkan semakin tinggi.Kata kunci: alkalisasi, hidrolisis asam, selulosa, MCC, rotan manau

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