scholarly journals Pyroelectrometallurgical processing of bismuth-containing oxides

2022 ◽  
Vol 25 (6) ◽  
pp. 795-806
Author(s):  
A. A. Korolev ◽  
S. V. Sergeichenko ◽  
K. L. Timofeev ◽  
G. I. Maltsev ◽  
R. S. Voinkov

In this work, we substantiate and develop a general pyroelectrometallurgical technology for processing bismuth dross and oxides (the intermediate products of lead bullion refining by the Betterton-Kroll process) to obtain crude bismuth. The research focuses on bismuth dross (3–5% Bi; 80–85% Pb) remelted at 500–600°С in the presence of NaNO3 and NaOH, as well as the obtained alkaline melt (bismuth oxides, 1–5% Bi; 60–70% Pb). The conducted experiments allowed us to determine optimal parameters of the main steps of processing bismuth oxide, as well as the characteristics of obtained products. Reduction smelting of bismuth oxides at 1150°C (with the addition of sodium carbonate, quartz and fine coke in the amount of 66, 25 and 5% of bismuth oxides mass, respectively) is proposed, leading to bismuth lead formation. Its decoppering is carried out at 350–600°C with 2.0% sulfur (by its weight), added to the melt. We propose to carry out the alkaline treatment of the decoppered Pb-Bi alloy at 500oC in contact with sodium hydroxide, sodium nitrate and sodium chloride, taken in amounts up to 10.2, 8.3 and 1.4% by weight of bismuth lead, respectively. Subsequent electrolysis comprises electrolytic processing of purified Pb-Bi alloy ingots at 550oC. The electrolyte consists of a melt with the following composition, %: NaCl – 7, KCl – 35, PbCl2 – 18 and ZnCl2 – 40. As a result, two end products were obtained by the proposed bismuth oxide processing. The anodic product at the second stage of electrolysis, crude bismuth (yielded 1.1% by the weight of oxides) contains 93.62% Bi and 4.14% Pb, extraction from oxides amounts to 19.0% Bi and 0.1% Pb. About 1.2% Bi and 9.1% Pb of their initial content in the oxides are transferred to the cathodic product containing 0.033% Bi and 97.83% Pb (the yield equalled 5.1% of the oxides).

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Noha Kattaya ◽  
Amr Abdelghany ◽  
Mahrous Meikhail ◽  
Osama Hemeda ◽  
Mohamed Ali

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Hongwei Gao ◽  
Vladimir V. Mazalov ◽  
Juan Xue

The problem of choosing the optimal parameters of service by carriers in public transport passenger flows is considered. This problem is modeled as a two-stage game. At the first stage, the players (carriers) select the parameters of their service (the number and schedule of vehicles, etc.). At the second stage, the players announce the prices of service and the consumers choose an appropriate service. The Wardrop equilibrium is applied to the competition model with rational consumers preferring the carriers with minimum cost, where the cost of service includes the price and also the expected trip time. The equilibrium in the pricing game is found and the optimal parameters of service as a solution to a noncooperative game are determined. Some results of computer simulations are presented.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Valerii A. Barbash ◽  
Olha V. Yashchenko ◽  
Olesia A. Vasylieva

Miscanthus x giganteus stalks were used to make organosolvent pulp and nanocellulose. The organosolvent miscanthus pulp (OMP) was obtained through thermal treatment in the mixture of glacial acetic acid and hydrogen peroxide at the first stage and the alkaline treatment at the second stage. Hydrolysis of the never-dried OМP was carried out by a solution of sulfuric acid with concentrations of 43% and 50% and followed by ultrasound treatment. Structural changes and the crystallinity index of OMP and nanocellulose were studied by SEM and FTIR methods. X-ray diffraction analysis confirmed an increase in the crystallinity of OMP and nanocellulose as a result of thermochemical treatment. We show that nanocellulose has a density of up to 1.6 g/cm3, transparency up to 82%, and a crystallinity index of 76.5%. The AFM method showed that the particles of nanocellulose have a diameter in the range from 10 to 20 nm. A thermogravimetric analysis confirmed that nanocellulose films have a denser structure and lower mass loss in the temperature range of 320–440°C compared to OMP. The obtained nanocellulose films have high tensile strength up to 195 MPa. The nanocellulose obtained from OMP exhibits the improved properties for the preparation of new nanocomposite materials.


2019 ◽  
Vol 7 (36) ◽  
pp. 20558-20566 ◽  
Author(s):  
Byung-Hyun Yun ◽  
Kyeong Joon Kim ◽  
Dong Woo Joh ◽  
Munseok S. Chae ◽  
Jong Jun Lee ◽  
...  

Highly conductive Dy and Y co-doped bismuth oxides combined with La0.8Sr0.2MnO3−δ significantly enhanced the ORR and OER as oxygen electrodes for reversible SOCs.


1958 ◽  
Vol 13 (10) ◽  
pp. 885-887 ◽  
Author(s):  
P. S. Aggarwal ◽  
A. Goswami

Two new forms of bismuth oxide (α0=5.65 Å and 7.02 Å) have been observed during the oxidation of bismuth films. The well-known tetragonal variety (a0=10.93 Å and c0=5.65 A) seems to be a superstructure form of oxide (I).


Author(s):  
Veslava Matikevičienė ◽  
Saulius Grigiškis ◽  
Donatas Levišauskas ◽  
Ona Kinderytė ◽  
Egidijus Baškys

The complex, effective and innovative cleaning technology for lipid-rich wastewater and pipelines contaminated by lipids, was developed. For this purpose, laboratory experiments were performed to verify the efficiency of bacterial preparation (Enterobacter aerogenes E13, Arthrobacter sp. N3 and Bacillus coagulans S1) to degrade the grease in water and in drainpipes. The results showed that selected microorganisms intensively degrade grease to light odourless precipitate, water and CO2, thus could be applied in industry. For optimization of technological cleaning processes, the response surface methodology was used. The optimal parameters for biological model wastewater treatment were determined: concentration of grease − 4.5–6.0 g/l, amount of bacterial preparation −5.5–6.0%, pH – 8–9. Due to optimization, the grease degradation rate increased by 20–30%. The optimization of drainpipe cleaning technology was achieved in two stages. During the first stage, the experiments were performed in laboratory flasks; during the second stage, optimized cleaning process was tested in a pilot plant. The following optimal parameters were set: pH – 8, amount of bacterial preparation –1.25 l/m2 and harness of water – 0.0 mmol/l. In water of medium hardness, the rate of biodegradation process is 15–20% less. A satisfactory efficiency of grease biodegradation was achieved in the pilot plant: the 86.7% of grease were digested in 21 days. Besides, living microorganisms were detected inside the clean drainpipe. Santrauka Sukurta kompleksinė, efektyvi ir inovacinė nuotekų bei vamzdynų, užterštų riebalais, valymo technologija. Atlikti laboratoriniai eksperimentai, siekiant nustatyti biopreparato, sudaryto iš Enterobacter aerogenes E13, Arthrobacter sp. N3 ir Bacillus coagulans S1, riebalų skaidymo efektyvumą kiek vandenyje, tiek vamzdyje. Gauti rezultatai parodė, kad atrinkti mikroorganizmai intensyviai skaido riebalus iki lengvų, neturinčių nemalonaus kvapo nuosėdų, vandens ir CO2, todėl gali būti taikomi pramonėje. Technologiniam valymo procesui optimizuoti taikyta reakcijos paviršiaus metodologija. Nustatyti optimalūs nuotekų, užterštų riebalais, valymo technologiniai parametrai: riebalų koncentracija – 4,5–6,0 g/l, biopreparato kiekis – 5,5–6,0%, pH – 8–9. Optimizavus procesą, riebalų skaidymo greitis padidėja 20–30 %. Vamzdžių, užterštų riebalais, valymo technologijos optimizavimas atliktas dviem etapais. Pirmajame etape eksperimentiniai tyrimai atlikti kolbose, antrajame etape optimizuotas procesas testuotas valant riebalinius teršalus bandomajame įrenginyje. Nustatyti optimalūs valymo parametrai: pH – 9, biopreparato kiekis – 1,25 l/m2 ir vandens kietis – 0,0 mmol/l. Esant vidutiniam vandens kiečiui biodagradacijos proceso greitis sumažėja 15–20%. Geras riebalų skaidymo efektyvumas pasiektas bandomajame įrenginyje, po 21 paros suskaidyta 86,7 % riebalų. Taip pat ant švaraus vamzdžio sienelių rasta gyvų mikroorganizmų. Резюме Создана комплексная, эффективная и инновационная технология очистки сточных вод и трубопроводов, загрязнённых липидами. С целью проверки эффективности бактериального состава (Enterobacter aerogenes E13, Arthrobacter sp. N3 и Bacillus coagulans S1) для расщепления жиров в воде и водосточной трубе были выполненылабораторные эксперименты. Полученные результаты показали, что отобранные микроорганизмы интенсивнорасщепляют жир до лёгкого осадка без побочного запаха воды и CO2 и могут быть применены в промышленности. Для оптимизации технологических процессов очистки использовался метод математического моделирования.Были определены оптимальные параметры для биологической обработки сточных вод: концентрация жира – 4,5– 6,0 г/л, количество бактериального состава – 5,5–6,0%, pH фактор – 8–9. После оптимизации скорость деградации жира увеличилась на 20–30%. Оптимизация технологии по очистке водосточных труб была выполнена на двухстадиях. На первой стадии эксперименты были выполнены в лабораторных колбах. На второй стадии оптимизационный процесс очистки был проведен в пилотной установке. Были установлены оптимальные параметры: pH фактор – 8, количество бактериального состава – 1,25 л/м2 и жёсткость воды – 0,0 ммол/л. В среднежёсткой водескорость процесса биологического распада была на 15–20% меньше. Хорошая биодеградация жира была установлена в пилотной установке. 86,7% жира было расщеплено за 21 день. Также в чистой водосточной трубе были обнаружены живые микроорганизмы.


Author(s):  
P.V. Vitchuk ◽  
◽  
N.D. Reykhert ◽  
N.A. Vitchuk ◽  
◽  
...  

The correct choice of elements of the elevator lifting mechanism and their parameters ensures its reliability, durability, energy and economic efficiency. The paper contains recommendations for the selection of the traction elements of the elevator lifting mechanism and the sequence of determining their parameters based on a multivariate calculation. The purpose of the proposed sequence is to obtain the most rational parameters of the traction elements of the elevator lifting mechanism. The initial data for the calculation are the lifting capacity of the elevator, the nominal speed of movement, the height of the lift of the car. It is also necessary to consider the purpose of the elevator. At the first stage of the calculation, the masses of the cab and the counterweight are determined. In this case, the existing data on analogue lifts should be used. In the absence of such data, the approximate dependences proposed by the authors of the article can be used. At the second stage, the kinematic scheme of the elevator is selected. At the third stage, the type of traction element is selected. On the basis of domestic and foreign experience in elevator engineering and well-known literature, recommendations are formulated for choosing the type of traction element. The final stage is a multivariate calculation of traction elements. It is proposed to evaluate the calculation results taking into account the minimum value of the safety factor in accordance with the EN 81-1: 1998 standard. The calculation of the traction elements considered in the work is only a small part of the process of determining the optimal parameters of the elements of the elevator lifting mechanism. At the same time, already at this stage, variability is introduced, which makes the calculation quite laborious to perform it manually. Obviously, a multivariate calculation method that allows you to analyze many different combinations of parameters of the elements of the elevator lifting mechanism and choose the optimal ones is impossible without the use of a computer.


RSC Advances ◽  
2015 ◽  
Vol 5 (45) ◽  
pp. 35365-35376 ◽  
Author(s):  
Prabhat Kumar Singh ◽  
Sushmita Banerjee ◽  
Arun Lal Srivastava ◽  
Yogesh Chandra Sharma

The kinetic, equilibrium modeling and adsorption characteristics of hydrous bismuth oxides (HBOs) have been investigated for the removal of nitrate from aqueous solutions.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5234 ◽  
Author(s):  
Mattia Bartoli ◽  
Pravin Jagdale ◽  
Alberto Tagliaferro

In this review, we reported the main achievements reached by using bismuth oxides and related materials for biological applications. We overviewed the complex chemical behavior of bismuth during the transformation of its compounds to oxide and bismuth oxide phase transitions. Afterward, we summarized the more relevant studies regrouped into three categories based on the use of bismuth species: (i) active drugs, (ii) diagnostic and (iii) theragnostic. We hope to provide a complete overview of the great potential of bismuth oxides in biological environments.


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