scholarly journals Analysis of technical and economic indicators of the pyrometallurgical scheme co-processing of red mud and scale

Author(s):  
Yu. A. Chesnokov ◽  
L. A. Marshuk ◽  
I. N. Tanutrov ◽  
M. N. Sviridova

Elaboration and implementation of effective technologies of utilization of alumina production wastes (red mud) is a rather actual task. Various variants of red mud and oiled rolling scale agglomeration considered aimed at their utilization at sinter and blast furnace plants to obtain conditional marketable cast iron. As the object of the study, red mud of OJSC RUSAL and oiled rolling scale of Sinarsky pipe manufacturing plant were used. It was shown, that their joint processing enables to obtain an agglomerated product having iron content more than 50%, which meets the modern requirements to the burden materials for blast furnaces. To determine the optimal scheme of the processing in the blast furnaces, various variants of studied materials agglomeration were calculated – an oxidizing roasting to obtain pellets and briquetting with application of burnt lime as a binder. The components interrelation in the mixture was selected to have iron content in the agglomerated product high enough at maximal possible volume of red mud utilization. The calculation analysis showed that interrelation 50% of red mud and 50% of oiled rolling scale meet the requirement. Calculated blast furnace heat indicators presented while applying briquettes and pellets from red mud and oiled rolling scale in the burden.

2021 ◽  
Vol 316 ◽  
pp. 673-677
Author(s):  
Irina V. Loginova ◽  
Aleksei V. Kyrchikov

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.


2019 ◽  
Vol 16 (31) ◽  
pp. 837-845
Author(s):  
Andrey B LEBEDEV ◽  
Vladimir A UTKOV ◽  
Olga A KAYGORODOVA ◽  
Marsel A KADYROV

There is a problem of using waste of alumina production from bauxite red mud. Warehousing of it is fraught with ecological catastrophes. Red muds constantly worsen the environment due to dusting and pollution of natural waters. Red mud is a product of bauxite processing. One ton of alumina accounts for 1 to 2.5 tons of red mud. Currently, it is not being processed, despite the availability of 3,000 publications and patents on this topic. One of them is justified by the ambiguity in the economic effectiveness of its use by consumers. In this paper, the options for economic and environmental efficiency of RM use are presented as substitutes for expensive lime and limestone used for purification of industrial gases emitted to the atmosphere in large quantities with toxic sulfur compounds. Laboratory and industrial tests revealed the sorption properties of red muds. When cleaning gases from sulfur emitted into the atmosphere by furnace gases, thermal power plants, sinter machines, and steelmaking furnaces. In addition, the ecological and technological efficiency of purification of sulfur-containing gases released in the areas of granulation of molten blast-furnace slags is shown.


2020 ◽  
Author(s):  
Yu. A. Chesnokov ◽  
L. A. Marshuk ◽  
I. N. Tanutrov ◽  
M. N. Sviridova

The analysis of various options for the use of alumina production wastes (red mud) and oiled scale using various methods of agglomeration to produce conditioned commercial iron is presented. Co-processing utilization of red mud and oiled scale allows to obtain raw materials with an iron content of more than 50%, which meets the modern requirements for charge materials for use in the blast furnace process. The calculation analysis carried out using a mathematical model of blast furnace process, allowed to determine the optimal proportion of the iron-containing material for the partial replacement of charge materials without reducing the technical and economic indicators of blast furnace smelting. Keywords: Bayer process, red mud, oiled scale, mathematical model, blast furnace process, metallurgical properties, complex utilization


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiangzhou Liang ◽  
Yongsheng Ji

AbstractRed mud, a by-product of alumina production, has a great impact on the environment due to its high alkalinity. In this paper, two-part geopolymer mortar was synthesized by combining red mud and blast furnace slag (BFS) to obtain optimized compressive strength and flexural strength for construction materials. Geopolymer concrete was prepared with the cementitious material in the concrete replaced by geopolymer mortar. Mechanical properties, permeability and microscopic properties of geopolymer concrete were measured. The results showed that the compressive strength grade of concrete prepared with geopolymer concrete can reach 54.43 MPa indicating that the geopolymer concrete can be used as materials for load-bearing members in structures. Due to lower total porosity and better pore structure, the permeability resistance of geopolymer concrete was significantly better than ordinary concrete. Microscopic analysis indicated that a large amount of aluminosilicate reaction products was generated in a geopolymer by the reaction of OH− with the aluminosilicate components in red mud and BFS in a strongly alkaline environment. The surface [SiO4]4− and [AlO4]4− tetrahedrons form chemical bonds through dehydroxylation, which is the direct reason for their high strength and determines their excellent physical and chemical properties.


2017 ◽  
Vol 47 (8) ◽  
pp. 576-578 ◽  
Author(s):  
V. L. Trushko ◽  
V. A. Utkov ◽  
A. A. Sivushov

2018 ◽  
Vol 4 (11) ◽  
pp. 6
Author(s):  
Upendra Kumar ◽  
Avinash Patidar ◽  
Bhupendra Koshti

The design and control of blast furnace (BF) ironmaking must be optimized in order to be competitive and sustainable, particularly under the more and more demanding and tough economic and environmental conditions. To achieve this, it is necessary to understand the complex multiphase flow, heat and mass transfer, and global performance of a BF. In this paper injection of alternative reducing agents via lances in the tubers of blast furnaces is discussed to reduce the consumption of metallurgical coke. Besides liquid hydrocarbons and pulverized coal the injection of recycled waste plastics is possible, offering the opportunity to chemically reuse waste material and also utilize the energy contained in such remnants.


2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad

This article presents the influence of the properties of the materials in the geopolymeric mixture, ground granulated blast furnace slag (GGBFS) + wheat straw ash (WSA) + uncalcined red mud (RMu), and ground granulated blast furnace slag + wheat straw ash + calcined red mud (RMc), over the microstructure and mechanical properties of the synthesised geopolymers. The activation solutions used were a NaOH solution with 8M concentration, and a solution realised from 50%wt NaOH and 50%wt Na2SiO3. The samples were analysed: from the microstructural point of view through SEM microscopy; the chemical composition was determined through EDX analysis; and the compressive strength tests was done for samples tested at 7 and 28 days, respectively. The SEM micrographies of the geopolymers have highlighted a complex structure and an variable compressive strength. Compressive strength varied from 24 MPa in the case of the same recipe obtained from 70% of GGBFS + 25% WSA +5% RMu, alkaline activated with NaOH 8M (7 days testing) to 85 MPa in the case of the recipe but replacing RMu with RMc with calcined red mud, alkaline activated with the 50%wt NaOH and 50%wt Na2SiO3 solution (28 days testing). This variation in the sense of the rise in compressive strength can be attributed to the difference in reactivity of the materials used in the recipes, the curing period, the geopolymers structure, and the presence of a lower or higher rate of pores, as well as the alkalinity and the nature of the activation solutions used.


Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1571
Author(s):  
Pavel Grudinsky ◽  
Dmitry Zinoveev ◽  
Denis Pankratov ◽  
Artem Semenov ◽  
Maria Panova ◽  
...  

Red mud is an iron-containing waste of alumina production with high alkalinity. A promising approach for its recycling is solid-phase carbothermic roasting in the presence of special additives followed by magnetic separation. The crucial factor of the separation of the obtained iron metallic particles from gangue is sufficiently large iron grains. This study focuses on the influence of Na2SO4 addition on iron grain growth during carbothermic roasting of two red mud samples with different (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21, respectively. Iron phase distribution in the red mud and roasted samples were investigated in detail by Mössbauer spectroscopy method. Based on thermodynamic calculations and results of multifactorial experiments, the optimal conditions for the roasting of the red mud samples with (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21 were duration of 180 min with the addition of 13.65% Na2SO4 at 1150 °C and 1350 °C followed by magnetic separation that led to 97% and 83.91% of iron recovery, as well as 51.6% and 83.7% of iron grade, respectively. The mechanism of sodium sulfate effect on iron grain growth was proposed. The results pointed out that Na2SO4 addition is unfavorable for the red mud carbothermic roasting compared with other alkaline sulfur-free additives.


2020 ◽  
Vol 0 (10) ◽  
pp. 35-40
Author(s):  
S.I. Gertsyk ◽  
◽  
I.V. Belyakov ◽  

The formation probability of nitrogen oxides in combustion products of mixed blast-furnace and natural gases under different conditions of combustion was calculated. It has been found out that heating the air incoming into burners of high-temperature blast-furnaces sharply increases concentration of nitrogen oxides in combustion products (by 1.5-1.75 times). It was notices that in furnaces where temperature was less than 950-1000 °С, heating the air up to 400 °С increased NOx content in gases released to the atmosphere no more than by 20-23%, and oxide concentration was in limits of sanitary standards.


2021 ◽  
Vol 13 (20) ◽  
pp. 11298
Author(s):  
Alessio Occhicone ◽  
Mira Vukčević ◽  
Ivana Bosković ◽  
Claudio Ferone

The aluminum Bayer production process is widespread all over the world. One of the waste products of the Bayer process is a basic aluminosilicate bauxite residue called red mud. The aluminosilicate nature of red mud makes it suitable as a precursor for alkali-activated materials. In this work, red mud was mixed with different percentages of blast furnace slag and then activated by sodium silicate solution at different SiO2/Na2O ratios. Obtained samples were characterized by chemical–physical analyses and compressive strength determination. Very high values of compressive strength, up to 50 MPa, even for high percentage of red mud in the raw mixture (70 wt.% of RM in powder mixture), were obtained. In particular, the higher compressive strength was measured for cubic samples containing 50 wt.% of RM, which showed a value above 70 MPa. The obtained mixtures were characterized by no or scarce environmental impact and could be used in the construction industry as an alternative to cementitious and ceramic materials.


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