CC BY
6
SRSTI 53.37.01
https://doi.org/A0.48081/QVNL7512
*L. B. Tolymbekova1, A. M. Aubakirov2, Kh. B. Temirtas3
1,2,3Toraighyrov University, Republic of Kazakhstan, Pavlodar * e-mail: lyazat-t@mail.ru
THE USAGE OF PETROLEUM COKE AS A REDUCING AGENT IN THE SINTERING BRANCH IN THE PRODUCTION OF ALUMINA
This article presents the results of studies on the possibility of using an alternative type of reducing agent used in the sintering branch instead of a reducing mixture of Kuznetsk anthracite and Shubarkol coke.
The given comparative characteristics of the reducing mixture currently used at Aluminum of Kazakhstan JSC and the proposed alternative — petroleum coke, show the possibility of the latter in its application: petroleum coke, in comparison with the used reducing agents, is characterized by a low level of ash content (0.2 % vs. 15.8 %) and reduced working physical moisture (5.0 % vs. 11.2 %), as well as high lower calorific value (7900 kcal/kg vs. 5863 kcal/kg) and high carbon content (88.0 % vs. 75.1 %).
Two compositions of the slurry charge were prepared for the experiments using the compared reducing agents: a mixture of Kuznetsk anthracite and Shubarkol coke, as well as petroleum coke.
During the experiment, a decrease in the specific consumption of the proposed reducing agent per unit of sinter by 7.4 % was revealed due to the reduced moisture content in the tested petroleum coke in comparison with the reduction mixture used. There is also an increase in the content of Al2O3 to 88.9 % and Na2O to 96.1 %.
Keywords: aluminum production, reducing agent, sintering branch, aluminate solution, alumina, red sludge.
Introduction
To date, due to the deterioration of the quality of raw materials in the aluminum industry, special attention is paid to the regulation of the composition of charge materials, in particular, in the sintering branch, for the full extraction of the necessary components Al2O3 and Na2O and their transfer to an aluminate solution [1-5]..
One of the indicators influencing the quality of the resulting aluminate solution is the selection of a reducing agent that is part of the sintering charge [6-8].
At the moment, a reducing mixture consisting of anthracite from the Kuznetsk coal basin and coke from Shubarkol Komir JSC is used as a reducing agent for the sintering charge [9,10].
Materials and methods
As an alternative to the reducing agent, it was proposed to use petroleum coke from UPNK-PV LLP.
The chemical composition of the reducing agents is given in Table 1.
Table 1 - The chemical composition of the reducing agents
Name The chemical composition
Wp Wa Aa Va S Qr Qdaf Corg
% kcal/kg %
Reducing agents used: anthracite and coke
Anthracite 10.6 0.9 14.7 2.9 0.2 5 863 7 953 75.1
Coke 11.7 0.3 16.8 2.9 0.4 5 496 7 761 75.1
Test petroleum coke
Petroleum coke 5.0 0.5 0.2 8.3 1.5 7 900 8 600 88.0
For comparison, two compositions of slurry charge were used as feedstock, using as a reducing agent:
anthracite from the Kuznetsk coal basin and coke from Shubarkol Komir JSC; test petroleum coke from UPNK-PV LLP.
During the laboratory experiment, a charge was prepared from the dry components that make up the sintering charge of the Pavlodar Alumina Plant in the following dosages given in Table 2:
Table 2 - Initial charge
Name Charge №1 Charge №2
gr gr
Red sludge 75.00 75.00
Limestone 46.00 45.40
Soda ash Achinsk 8.00 7.70
Bauxite 9.10 9.20
Reductant 3.30 2.65
Total 141.40 139.95
Charge № 1 was made taking into account the reducing agent used, charge № 2 was made taking into account the tested petroleum coke.
The raw material was thoroughly crushed and, based on the calculated dosages measured on laboratory scales, mixed in preheated corundum cups.
Then the resulting charge was placed in a laboratory high-temperature furnace and sintered at a temperature of 1140 °C for two hours.
The resulting product was slowly cooled in the furnace, and then in the air, to room temperature.
The products of each experimental sintering were crushed and leached with an alkaline solution at a temperature of 70 °C. The results of sintering of the charge and sludge of standard leaching are presented in Table 3:
Table 3 - Composition of sinter and leaching sludge
Name Sinter Standard leaching sludge
Sieve characteristic Chemical analysis Modules Content Extraction
-1 mm Al2O3 Fe2°3 SO3 М t caust M,Uc N2O Al2O3 N2O Al2O3 S O 3 sludge
% % ед. % % %
Charge №1 39.G 19.3 1б.8 3.3 1.G91 2.G81 1.G1 3.87 95.4 8б.7 7.G
Charge №2 2б.б 19.8 1б.7 3.3 1.11G 2.1GG G.98 3.41 9б.1 88.9 1G.1
Results and discussions
During the experiment, a decrease in the specific consumption of the reducing agent was revealed due to the reduced moisture content in the tested petroleum coke in comparison with the reduction mixture used. Data on the specific consumption of the reducing agent per ton of sinter are given in Table 4:
Table 4 - Specific consumption of the reducing agent
Name Amount of charge, gram Amount of sinter, gram Amount of reducing agent, gram Specific consumption of reducing agent, gram per gram of sinter
Reducing mixture of Pavlodar Alumina Plant 141.4 128.55 3.3 0.0257
Petroleum coke 139.95 111.43 2.65 0.0238
Conclusion
The use of petroleum coke has a number of advantages over the reducing agents used:
- petroleum coke, in comparison with the used reducing agents, is characterized by a low ash content (0.2 % vs. 15.8 %) and reduced working physical moisture (5.0 % vs. 11.2 %), as well as a high lower heat of combustion (7900 kcal/kg vs. 5863 kcal/kg) and a high carbon content (88.0 % vs. 75.1 %);
- the specific consumption of petroleum coke per unit of sinter was reduced by 7.4 % in comparison with the reducing agent used (0.0238 g/g vs. 0.0257 g/g);
- the results of laboratory standard leaching of sinters indicate an increased extraction of useful components when using petroleum coke for the preparation of the charge: up to 88.9 % for Al2O3; up to 96.1 % for Na2O.
Thus, the use of petroleum coke with UPNK-PV LLP as a reducing agent will improve the technical and economic indicators of the sintering process, as well as increase the degree of extraction of useful components.
REFERENCES
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Material received on 06.02.23.
*Л. Б. Толымбекова1, А. М. Аубакиров2, Х. Б. Темiрmас3
1'2'3ТораЙFыров университет^ Казахстан Республикасы, Павлодар к. Материал 06.02.23. баспаFа тYстi.
АЛЮМИНИЙ ТОТЬНЫН 0НД1РУДЕ ЦАЦТАУ ТАРМАFЫНДА ТОТЬЩСЫЗДАНДЬ^ЫШ РЕТ1НДЕ М¥НАЙ КОКСЫН ПАЙДАЛАНУ
Бул мацалада Кузнецк антрацитi мен Шубаркел кокс тотыцсыздандыргыш цоспасыныц орнына цацтау тармагында цолданылатын тотыцсыздандыргыштыц балама турт цолдану мумктдш туралы зерттеу нэтижелерi келтiрiлген.
Бyгiнгi куш «Казацстан алюминиш» АК,-да цолданылатын цалпына келтiру цоспасыныц жэне усынылатын балама — мунай коксыныц келтiрiлген салыстырмалы сипаттамалары оныц цолданылу мумктдшн кврсетедi: мунай коксы пайдаланылатын тотыцсыздандыргыштармен салыстырганда кул цурамыныц темен децгешмен (0,2 % 15,8 %-га царсы) жэне жумыс физикалыц ылгалыныц темендеуiмен (5,0 % 11,2 %-га царсы) сипатталады, сондай-ац жогары темен жану жылуы (7900 ккал/кг 5863 ккал/кг-га царсы) жэне жогары кемiртегi (88,0 % 75,1 %-га царсы);
Эксперименттер жyргiзу ушш салыстырмалы тотыцсыздандыргыштарды цолдана отырып, шламды шихтаныц ет цурамы дайындалды: Кузнецк антрацитi мен Шубаркел кокс цоспасы, сондай-ац мунай коксы.
Эксперимент барысында сыналатын мунай кокс цурам^гндаг^г ылгалдыц азаюына байланысты цолданылатын тотыцсыздандыргыш цоспамен салыстырганда усытыган тотыцсыздандыргыштыц куйежентек бiрлiгiне шаццандагы улестж ш^ггыныныц 7,4 %-га теменде)4 аныцталды. Сондай-ац, А12<Э} цурамыныц 88,9 %-га жэне ^20-ныц 96,1 %-га дешн жогарылауы байцалады.
Кiлттi сездер: алюминий ендiрiсi, тотыцсыздандыргыш, цацтау тармагы, алюминий ертшдШ, глинозем, цызыл шлам.
*Л. Б. Толымбекова1, А. М. Аубакиров2, Х. Б. Темiрmас3
1,2,3Торайгыров университет, Республика Казахстан, г. Павлодар.
Материал поступил в редакцию 06.02.23.
ИСПОЛЬЗОВАНИЕ НЕФТЯНОГО КОКСА В КАЧЕСТВЕ ВОССТАНОВИТЕЛЯ В ВЕТВИ СПЕКАНИЯ ПРИ ПРОИЗВОДСТВЕ ГЛИНОЗЕМА
В данной статье представлены результаты исследований возможности использования альтернативного вида восстановителя, применяющегося в ветви спекания взамен восстановительной смеси Кузнецкого антрацита и кокса Шубарколь.
Приведенные сравнительные характеристики применяющейся на сегодняшний день на АО «Алюминий Казахстана» восстановительной смеси и предлагаемой альтернативы — нефтяного кокса, показывают возможность последнего в его применении: кокс нефтяной в сравнении с используемыми восстановителями характеризуется низким уровнем содержания зольности (0,2 % против 15,8 %) и пониженной рабочей физической влагой (5,0 % против 11,2 %), а также высокой низшей теплотой сгорания (7900 ккал/кг против 5 863 ккал/кг) и высоким содержанием углерода (88,0 % против 75,1 %);
Для проведения экспериментов были подготовлены два состава шламовой шихты с применением сравниваемых восстановителей: смесь Кузнецкого антрацита и кокса Шубарколь, а также нефтяного кокса.
В процессе эксперимента было выявлено снижение удельного расхода предлагаемого восстановителя на единицу спека на 7,4 % из-за уменьшенного содержания влаги в испытуемом нефтяном коксе в сравнении с используемой восстановительной смесью. Также отмечается повышение содержания А120} до 88,9 % и Шр до 96,1 %.
Ключевые слова: алюминиевое производство, восстановитель, ветвь спекания, алюминатный раствор, глинозем, красный шлам.
