scholarly journals THE EFFECT OF METAL ADDITIVES ON CONVERSION HEMATITE IN THE PROCESSING OF BAUXITE BY THE BUYER METHOD

2021 ◽  
pp. 809-817
Author(s):  
Светлана Александровна Бибанаева ◽  
Владимир Михайлович Скачков
Keyword(s):  
Red Mud ◽  
Sodium Content ◽  
Hydrogen Gas ◽  
Raw Material ◽  
Quantitative Composition ◽  
Magnetic Fraction ◽  
Autoclave Leaching ◽  
Composition And Structure ◽  
Metal Additives ◽  
High Degree

Работа посвящена изучению влияния моно- и сложносоставных металлических добавок на процесс переработки бокситов гидрощелочным способом. Изучен химический качественный и количественный состав, морфология красных шламов (КШ) полученных в условиях автоклавного высокотемпературного выщелачивания. Проведены рентгенофазовые исследования, направленные на определение состава и структуры соединений в красном шламе. Показана перспективность метода автоклавного выщелачивания трудновскрываемых бокситов с одновременным извлечением глинозема и конверсии гематита в магнетит газообразным водородом. Установлено, что способ позволяет переработку бокситов с высокой степенью извлечения глинозема и позволяет получать красные шламы с различным содержанием магнитной фракции и низким содержанием натрия. Полученный магнетизированный красный шлам пригоден для переработки с помощью магнитной сепарации и делает перспективным сырьем для черной металлургии. Определена зависимость степени конверсии гематита в магнетит от вида восстанавливающего агента. По результатам исследований был получен патент на изобретение. The work is devoted to the study of the influence of mono - and composite metal additives on the process of processing bauxite by the hydro-alkaline method. The chemical qualitative and quantitative composition, morphology of red mud (RM) obtained under conditions of autoclave high-temperature leaching were studied. X-ray phase studies aimed at determining the composition and structure of compounds in red mud were carried out. The prospects of the method of autoclave leaching of hard-to-open bauxites with simultaneous extraction of alumina and conversion of hematite to magnetite by hydrogen gas are shown. It was found that the method allows the processing of bauxite with a high degree of alumina extraction and allows to obtain red mud with different magnetic fraction content and low sodium content. The resulting magnetized red mud is suitable for processing by magnetic separation and makes it a promising raw material for the ferrous metallurgy. The dependence of the degree of conversion of hematite to magnetite on the type of reducing agent is determined. According to the results of the research, a patent for the invention was obtained.

The Study of the Magnetic Properties of Red Mud from Alumina Production after Alkaline Treatment

2021 ◽  
Vol 316 ◽  
pp. 673-677
Author(s):  
Irina V. Loginova ◽  
Aleksei V. Kyrchikov
Keyword(s):  
Magnetic Properties ◽  
Cast Iron ◽  
Red Mud ◽  
Iron Content ◽  
Alkaline Treatment ◽  
Raw Material ◽  
Magnetic Fraction ◽  
Alumina Production ◽  
Aluminum Compounds ◽  
Vanadium Titanium

In Russia, the main feedstock for producing aluminum is bauxite. During the processing of 1 ton of bauxite into alumina (Al2O3), up to 0.5–0.6 ton of techno-genic waste is formed, that is red mud. It is not currently disposed of and accumulated in mud tailing dumps. It contains valuable components: Al – 8 %; Fe – 25 %; Ti – 2.4 % and it can be considered as a potential raw material for ferrous metallurgy and as a source of vanadium, titanium, and rare-earth elements (REE) Sc, Y, La. The paper shows the possibility of obtaining red mud with an increased iron content of up to 36 %, with an additional extraction of aluminum. Red mud from the Ural Aluminum Plant (Russia) is considered. It is proposed to direct this mud to the production of pellets for the production of cast iron. To extract aluminum from red mud, it is proposed to process the mud in a highly alkaline medium by sintering in the temperature range 300–600 °C. The resulting sinter is leached with water or a slightly alkaline solution with the conversion of aluminum compounds into solution. The red mud, obtained this way, exhibits magnetic properties. A magnetic separation was carried out, and the yield of the magnetic fraction is 79.87 %. The iron content increases by 25 % and amounts to 51.88 % of Fe2O3.

scholarly journals EFFECT OF METAL ADDITIVES IN HYDROCHEMICAL PROCESSING OF DIASPORE-BEMITE BAUXITE ON PHYSICOCHEMICAL PROPERTIES OF REDUCED MUDS

2020 ◽  
pp. 784-791
Author(s):  
Светлана Александровна Бибанаева ◽  
Лилия Александровна Пасечник ◽  
Владимир Михайлович Скачков ◽  
Владимир Трофимович Суриков ◽  
Сергей Павлович Яценко
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
Red Mud ◽  
Optimal Parameters ◽  
X Ray ◽  
Composition And Structure ◽  
Chemical Studies ◽  
Metal Additives ◽  
New Compounds ◽  
Physical And Chemical

Работа посвящена изучению высокотемпературного гидрохимического разложения минеральных комплексов диаспор-бемитовых бокситов методом Байера с извлечением макрокомпонентов - алюминия и железа в присутствии металлических восстановителей. Проведены рентгенофазовые исследования, направленные на определение состава и структуры новых соединений в магнетизированном красном шламе. По результатам физико-химических исследований продуктов выщелачивания рекомендованы оптимальные параметры восстановительного выщелачивания бокситов СУБРа, направленные на извлечение алюминия и синтез магнетита. Выявлены закономерности влияния вида металлического восстановителя на морфологию, фазовый состав, размер частиц в красном шламе (КШ). The work is devoted to study of the high-temperature hydrochemical decomposition of mineral complexes of diaspore-bemite bauxites by the Bayer method with the extraction of macro-components-aluminum and iron in the presence of metal reducing agents. X-ray phase studies were performed to determine the composition and structure of new compounds in magnetized spent red mud. Based on the results of physical and chemical studies of leaching products, optimal parameters for reducing leaching of bauxite are recommended, aimed at extracting aluminum and synthesizing magnetite. The regularities of the influence of the type of metal reducing agent on the morphology, phase composition, and particle size in the red mud are revealed.

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

Meat qualities in the sheep with special reference to Scottish breeds and crosses. I

1939 ◽  
Vol 29 (4) ◽  
pp. 544-626 ◽  
Author(s):  
H. Pálsson
Keyword(s):  
Scientific Basis ◽  
Accurate Estimate ◽  
Quantitative Composition ◽  
Carcass Quality ◽  
Strongly Correlated ◽  
Precise Measure ◽  
Total Fat ◽  
Highly Correlated ◽  
High Degree ◽  
The Relationship

1. By establishing the relationship between linear carcass measurements and the quantitative composition of the carcass in terms of bone, muscle and fat, we have provided a scientific basis for the use of many measurements hitherto only presumed to provide an index to carcass quality.2. External carcass measurements are correlated with weight of the skeleton. The most useful for this purpose are length of tibia + tarsus and length of the fore-cannon.3. As indices of muscle, external measures are only of indirect value. Thus, both F – T and G/F × 100 are strongly correlated with weight of muscle as a percentage of skeletal weight.4. Similarly, F provides an index of fat, being negatively correlated with fat as a percentage of bone.5. For muscle and fat internal measures permit a more precise estimate to be made. A + B is the best index of the former while C + J + Y provide the most accurate estimate of the weight of fat.6. Still better indices for muscle and fat are provided by suitable combinations of external and internal measurements. Thus L/10 + A + B is very highly correlated with the weight of muscle, and L/10 × (C + J + Y) is the best index of fat in the hoggets. For bone, a most efficient single index is shown to be the weight of the fore-cannon bone.7. The weight of the skeleton can be estimated with a high degree of accuracy from the weight of the bones in either one leg or loin. Both these joints combined, however, provide a still better estimate.8. The muscle in one leg or loin + leg provides an excellent index of the weight of muscle in the whole carcass.9. The fat in one leg, loin, or both these joints combined provides a good index of the weight of the total fat in the carcass. Both joints combined give the most precise measure.10. The value of certain measurements which are not necessarily associated with the quantity of the major tissues of the carcass, but which nevertheless have important qualitative significance, is emphasized.

scholarly journals MATHEMATICAL MODELING OF LEACHING PROCESS OF RED MUD IN ORDER TO OBTAIN THE KINETICS PARAMETERS

2015 ◽  
Vol 14 (2) ◽  
pp. 90 ◽  
Author(s):  
K. L. M. Dos Passos ◽  
B. M. Viegas ◽  
E. N. Macêdo ◽  
J. A. S. Souza ◽  
E. M. Magalhães
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Red Mud ◽  
Mineralogical Composition ◽  
Raw Material ◽  
Data Conversion ◽  
Kinetics Parameters ◽  
Leaching Process ◽  
Iron Leaching ◽  
The Mathematical Model

The use of the waste of the Bayer process, red mud, is due to its chemical and mineralogical composition that shows a material rich in oxides of iron, titanium and aluminum. Some studies conducted show that this waste can be applied as a source of alternative raw material for concentration and subsequent recovery of titanium compounds from an iron leaching process, which is present in higher amounts, about 30% by weight. To obtain a greater understanding about the leaching kinetics, the information of the kinetic data of this process is very important. In this context, the main objective of this work is the development of a mathematical model that is able to fit the experimental data (conversion / extraction iron, titanium and aluminum) of the leaching process by which is possible to obtain the main kinetic parameters such as the activation energy and the velocity of chemical reactions as well as the controlling step of the process. The development of the mathematical model was based on the model of core decreasing. The obtained model system of ordinary differential equations was able to fit the experimental data obtained from the leaching process, enabling the determination of the controlling step, the rate constants and the activation energies of the leaching process.

scholarly journals INFLUENCE OF THE RATE OF IRON HEXATIANOFERRATE ON ITS SORPTION ABILITY IN RELATION TO SILVER, INDIUM AND GALLIUM CATIONS

2021 ◽  
pp. 5-14
Author(s):  
А.А. Agatayeva ◽  
◽  
U.Zh. Jussipbekov ◽  
R.М. Chernyakova ◽  
R.А. Kaiynbayeva ◽  
...  
Keyword(s):  
Scientific Literature ◽  
Precious Metals ◽  
Sorption Process ◽  
Raw Material ◽  
Channel Diameter ◽  
Residual Content ◽  
Initial Iron ◽  
Sorption Ability ◽  
High Degree ◽  
Degree Of Sorption

The processing of phosphorites into elemental phosphorus is accom-panied by the formation of waste - cotrile "milk", in which indium, gallium, and silver are present. This waste can be considered as a cheap raw material for the production of rare and precious metals. In the scientific literature there are data on the sorption capacity of hexacyano-ferrates of iron, which has a crystal lattice with a channel diameter from 3.0 to 3.5Å. Investigation of the sorption process in the model system "Fe4[Fe(CN)6]3·10H2O - Ag+- In3+- Ga3+ - H2O" depending on the norm of iron hexacyanoferrate (sorbent). The initial concentration of silver, indium and gallium ions and their residual content in solutions were determined using the atomic absorption spectrophotometer "PerkinElmer Analyst 400" (USA). The microstructure of the initial iron hexacyanoferrate and iron hexacyano-ferrate, after sorption, was studied on the CarlZeissFESEM and JEOL brand "JXA-8230" (Japan). With a ratio to T:W equal to 1.75-2.5:100, the degree of sorption of Ag+ with iron hexacyanoferrate is 99.5 and 99.8 %. The highest degree of sorption (96.75%) of In3+ ions can be obtained with a sorbent weighing 3 g per 100 g of solution at 60oC. A high degree of sorption of Ga3+ cations is achieved at low (0.5:100 wt. h.) and high (3:100 wt. h.) consumption of iron hexacyanoferrate. It was revealed that iron hexacyanoferrate exhibits sorption properties simultaneously with respect to mono- and trivalent metals, and the basic laws of their sorption were established.

scholarly journals ДОСЛІДЖЕННЯ ГІГІЄНІЧНИХ ВЛАСТИВОСТЕЙ МАТЕРІАЛІВ НАТІЛЬНОЇ ЛІКАРНЯНОЇ БІЛИЗНИ

2020 ◽  
Vol 140 (6) ◽  
pp. 38-47
Author(s):  
І. О. Іванов ◽  
Н. П. Супрун ◽  
Ю. О. Ващенко
Keyword(s):  
Comparative Analysis ◽  
Materials Science ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Raw Material ◽  
Experimental Investigations ◽  
Textile Materials ◽  
Composition And Structure ◽  
Innovative Materials ◽  
Basic Functions

Investigation of the influence of the peculiarities of raw material composition and structure of traditional and innovative linen textile materials on their hygienic properties. Theoretical and experimental investigations are based on the main positions of textile materials science. In experimental studies, modern standardized methods for determining the hygienic properties of textile materials were used, as well as techniques specially developed taking into account the peculiarities of the operating conditions of underwear. The peculiarities of the operating conditions and the basic functions of hospital underwear were determined. The comparative analysis of hygienic properties of traditional and modern fabrics for underwear was carried out. Using the standardized and the developed methods, adapted to the peculiarities of the conditions of use of the products, the indicators characterizing the processes of water absorption of the materials were experimentally determined. On the basis of the obtained values of quality indicators, a comprehensive assessment of the ability of materials to transfer moisture and air, with the calculation of the arithmetic complex quality index was done. This allowed to determine the material that is optimal in properties, which provides thermophysiological comfort when operating hospital underwear. Using the developed methods, which take into account the specifics of the operating conditions, a comparative analysis of the hygienic properties of traditional and innovative materials for underwear was carried out. A new range of textile materials for underwear has been proposed, taking into account the peculiarities of the operational situation of consumption.

scholarly journals Red Mud-Based Polyaluminum Ferric Chloride Flocculant: Preparation, Characterization and Flocculation Performance

2021 ◽  
Author(s):  
Yong Cheng ◽  
Longjun Xu ◽  
Chenglun Liu ◽  
Zao Jiang ◽  
Qiyuan Zhang ◽  
...  
Keyword(s):  
Red Mud ◽  
High Efficiency ◽  
Low Cost ◽  
Oxygen Demand ◽  
Industrial Applications ◽  
Iron Chloride ◽  
Raw Material ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
Solution Ph

Abstract In this work, red mud was used as raw material to extract Al and Fe with hydrochloric acid. The high-efficiency polyaluminum iron chloride (PAFC) flocculant was prepared via adjusting the pH of the leaching solution, the molar ratio of aluminum and iron, and the polymerization temperature. The effect of synthesis and flocculation conditions on the flocculation performance of aged landfill leachate was investigated. The results confirmed that the PAFC prepared at the polymerization pH of 2.5, the Al/Fe molar ratio of 8, and the polymerization temperature of 70 °C had the optimum flocculation effect. The flocculation consequences of PAFC and commercial polyaluminum iron chloride flocculant (CPAFC) under different flocculation conditions were compared. The chemical oxygen demand (COD), UV254, chroma and settlement height of PAFC at flocculant concentration of 60 g/L and solution pH of 6 were 72.2%, 79.2%, 82.9% and 9.5 cm (within 90 min), respectively. PAFC has excellent flocculation performance and can be used as a simple, potentially low-cost wastewater treatment agent in industrial applications.

scholarly journals Berries and Leaves of Actinidia kolomikta (Rupr. & Maxim.) Maxim.: A Source of Phenolic Compounds

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 147
Author(s):  
Laima Česonienė ◽  
Paulina Štreimikytė ◽  
Mindaugas Liaudanskas ◽  
Vaidotas Žvikas ◽  
Pranas Viškelis ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Radical Scavenging ◽  
Total Content ◽  
Ascorbic Acid Content ◽  
Free Radical Scavenging ◽  
Raw Material ◽  
Quantitative Composition ◽  
Pharmaceutical Industries

Berries of Actinidia kolomikta (A. kolomikta) are known for high ascorbic acid content, but the diversity of phenolic compounds has been little studied. The present research aimed to investigate phenolic compounds and antioxidant activity in berries and leaves of twelve A. kolomikta cultivars. The UHPLC-ESI-MS/MS technique was used to determine differences among cultivars in the quantitative composition of individual phenolic compounds. Antioxidant activity was determined by DPPH• free radical scavenging and CUPRAC methods. In the present study, 13 phenolic compounds were detected in berries, whereas leaves contained 17 phenolic compounds. Flavonols were the primary class found in both berries and leaves; other identified phenolic compounds were flavan-3-ols, flavones and, phenolic acids; and dihydrochalcone phloridzin was identified in the leaves. The amount and variety of phenolic compounds in berries and leaves and antioxidant activity were found to be cultivar-dependent. The highest total content of phenolic compounds was found in the leaves of the cultivar ‘Aromatnaja’ and in the berries of the cultivar ‘VIR-2’. Results of this study have confirmed that berries and leaves of A. kolomikta could be a valuable raw material for both food and pharmaceutical industries.

scholarly journals Determination of pesticide residues by chromatographic methods for food safety

2021 ◽  
Vol 12 (3) ◽  
pp. 111-118
Author(s):  
N. Yu. Tereshchenko ◽  
◽  
O. Yu. Kursenko ◽  
O. I. Khyzhan ◽  
O. I. Khyzhan ◽  
...  
Keyword(s):  
Plant Extract ◽  
High Performance ◽  
Solid Phase ◽  
Raw Materials ◽  
Apple Fruit ◽  
Raw Material ◽  
Benzimidazole Derivatives ◽  
Quantitative Composition ◽  
Variable Component ◽  
Selective Solvents

The paper presents the methodology of preparation of samples of oilseeds, lettuce, apples for research by chromatographic control of xenobiotics of the following chemical groups of pesticides: benzimidazole derivatives, anilinopyrimidine derivatives, bipyridylium derivatives. The implementation of the following processes is considered: homogenization of the sample, purification of the extract by solid-phase or liquid-liquid extraction, obtaining a plant extract, obtaining an extract of analytes. For fine-grained homogenized samples of sunflower seeds, the optimal ratio of raw material -extragent is 1:20, for pasty homogenized samples of apple fruit - 1:10, for liquid samples of homogenized lettuce - 1: 5. Analysis of the distribution of xenobiotics in the system octane/water, the dipole moment of solvents allowed to determine the extractants that are able to dissolve and remove xenobiotics from raw materials. It was found that a mixture of acetonitrile and methanol (4: 1) should be used to remove benzimidazole derivatives and anilinopyrimidine derivatives, bipyridylium derivatives are best extracted with methanolic trifluoroacetic acid (9.5: 0.5). Quantitative analysis of xenobiotics content in extracts obtained from samples artificially enriched with xenobiotics was performed. The most complete xenobiotics were removed from samples of plant products containing traces of fat. The most difficult process of sample preparation is the process of obtaining sunflower seed extract. The content of xenobiotics in extracts obtained from samples artificially enriched in analytes is influenced by the temperature at which the process takes place and the duration of extraction. Based on the chemical composition of the sample matrix and the list of analytes, the conditions of the variable component of the methodology are proposed: obtaining plant extract under the action of selective solvents, homogenized raw material-solvent with constant stirring of the extraction system at 180-200 rpm, or under the action of ultrasonic vibrations with a frequency of 37 kHz from 4°C to 25°C for 5-25 minutes. The control of the qualitative and quantitative composition of the studied plant extracts and analyte extracts was investigated by the methods of high-performance liquid and gas chromatography (liquid and gas) with mass-selective detectors.

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