scholarly journals Recycling of Spent Pot Lining First Cut from Aluminum Smelters by Utilizing the Two-Step Decomposition Characteristics of Dolomite

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5283
Author(s):  
Yifei Wang ◽  
Xiping Chen ◽  
Shaojun Zhang ◽  
Peixu Yang
Keyword(s):  
Sodium Fluoride ◽  
Heating Temperature ◽  
Calorific Value ◽  
Primary Aluminum ◽  
Electrolytic Production ◽  
Calcination Process ◽  
Aluminum Smelters ◽  
Tiny Amount ◽  
High Level ◽  
Pidgeon Process

Spent Pot Lining First Cut (shortened to SPL-1cut) is a solid waste discharged from a primary aluminum electrolytic production process. SPL-1cut is classified as hazardous waste in China because it contains large amounts of soluble sodium fluoride and a tiny amount of cyanide. Most of SPL-1cut is carbon—about 65%—and its calorific value is 22.587 MJ∙kg−1. There is a high level of sodium fluoride in SPL-1cut—about 15%—and sodium fluoride is randomly distributed in the carbon granule. The recycling of SPL-1cut using dolomite as a reactant, based on the characteristics of the two-step decomposition of dolomite at a high temperature, is discussed. The recycling of SPL-1cut was performed under the following heating conditions: the heating temperature was 850 °C, the holding time was 120 min, and 40% of the dolomite was added to the SPL-1cut. It was found that the cyanides are completely oxidized and decomposed, and dolomite is decomposed into MgO and active CaCO3. At the same time, NaF reacts with active CaCO3 and converts into CaF2. The results provide references for using SPL-1cut as an alternative fuel in the dolomite calcination process of the Pidgeon Process.

Investigation of the modification effect on performance properties of cast iron molds

2021 ◽  
pp. 23-28
Author(s):  
V. A. Gulevskiy ◽  
◽  
S. N. Tsurikhin ◽  
V. V. Gulevskiy ◽  
N. Yu. Miroshkin ◽  
...  
Keyword(s):  
Cast Iron ◽  
Outer Surface ◽  
Heating Temperature ◽  
Primary Aluminum ◽  
Operating Conditions ◽  
Senior Lecturer ◽  
Advantages And Disadvantages ◽  
Stress And Deformation ◽  
Consumable Electrodes

Research is devoted to the influence of the technological method of modifying gray cast iron for the manufacture of steel casting molds. Heavy operation imposes stringent requirements both on the design of molds and on the materials from which they are made. They reliably withstand the effects of steel poured into them, having a temperature of 1600–1700 °C, thermal shock, which is directly proportional to this temperature, as well as significant effects of cyclic thermal stress and deformation. Specific operating conditions of molds (high heating temperature, their installation on movable and stationary ditches, intensive traffic flows, etc.) complicate the necessary processes directly during their operation. Modeling geometric shapes on a scale of geometric similarity 1:10. Tests were carried out on molds cast from cast iron for consumable electrodes, modified with ferrosilicon (FS65 GOST 1415-93), primary aluminum A99 (GOST 11069-2001), vanadium slag (SHVD-1 TU14-11-178-86), FSB-30) and silicomishmetal (SIMISH-1). These modifiers were chosen for modification, as they are widely used in production. Thus, the conducted studies of the nature of the deformation of the walls of the molds and the stress-strain state on models made of gray and modified cast iron make it possible to assess the advantages and disadvantages of the resulting structure and shape of graphite. Further, the methods of the rational formula of the outer surface of profiled and sheet molds are used, having predetermined the nature of destruction in advance. The use of thin-walled used rational forms can significantly reduce their specific consumption. The study of the quality of the metal cast into the experimental curved outer surface showed that the macrostructure of the metal of the experimental and ordinary ingots is the same. The work was attended by N.V Markina, senior lecturer at the Dept. of Machines and Foundry Technology, Volgograd State Technical University.

Structural state and thermodynamic stability of Al–Cu alloys

2020 ◽  
Vol 34 (08) ◽  
pp. 2050057
Author(s):  
Nataliia Filonenko
Keyword(s):  
Thermodynamic Stability ◽  
Crystallization Process ◽  
Heating Temperature ◽  
Liquidus Line ◽  
Primary Aluminum ◽  
Complete Suppression ◽  
Cu Alloy ◽  
Cu Alloys ◽  
High Temperature Expansion ◽  
First Time

It is known that processes occurring in binary system melts affect the crystallization process and the phase composition of alloys. To predict these processes, we should determine the region of thermodynamic stability of the melt. In this paper, the structural properties of hypoeutectic and hypereutectic alloys in Al–Cu system are studied depending on the heating temperature above the liquidus line and aftercooling rate. It is shown that overheating of Al–Cu melts to 150 K above the liquidus line and further cooling leads to complete suppression of the process of formation of primary aluminum crystals in hypoeutectic alloys and [Formula: see text] phase in hypereutectic alloys. For the first time, by accounting in Gibbs energy of binary Al–Cu alloy for the first degree approximation of high-temperature expansion of thermodynamic potential, the dependence of temperature of line of the melt thermodynamic stability on copper content in alloy is obtained.

Heat Treatment Effect on Properties of Al-Mg-Si-Cu 1370 Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 519-524 ◽  
Author(s):  
N.I. Kolobnev ◽  
L.B. Khokhlatova ◽  
S.V. Samokhvalov ◽  
A.A. Alekseev ◽  
S.V. Sbitneva ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heating Temperature ◽  
Solution Treatment ◽  
Phase Relationship ◽  
Dark Field ◽  
Intercrystalline Corrosion ◽  
Quenching Rate ◽  
Heat Treatment Regimes ◽  
Alloy Properties ◽  
High Level

The Russian 1370 Al-Mg-Si-Cu alloy (analogue of 6056) is an advanced material for the skin and stringers of fuselage. However, these alloys are susceptible to the intercrystalline corrosion depending on the heat treatment regimes. The investigations of the effect of heating temperature during the solid solution treatment (530-555)°C and quenching rate, ageing regimes and interval between the quenching and ageing on the structure and properties of 1370 alloy sheets were performed. The strengthening β (Mg2Si) -phase and Q (Al5Cu2Mg8Si6) -phase relationship dependence of the alloy properties is established. Using the dark field electron microscopy which permits to intensify separate diffraction reflexes of strengthening phases the structure of Q-phase precipitates has been studied. Optimization of heat treatment of 1370 alloy sheets provided the combination of fracture toughness characteristic (Kco= 100 MPa√m) high level, the ultimate strength of 400-420 MPa and intercrystalline corrosion no more 100 μm in depth.

scholarly journals DTA-TG Analysis of Gd0.95La0.05Ba1.95Sr0.05Cu3Oy Compounds

2020 ◽  
Vol 21 (1) ◽  
pp. 33
Author(s):  
Made Sumadiyasa ◽  
I Putu Suardana ◽  
Nyoman Wendri
Keyword(s):  
Sintering Temperature ◽  
Heating Temperature ◽  
Vital Role ◽  
Formation Temperature ◽  
Melting Reaction ◽  
Calcination Process ◽  
Melting Temperatures ◽  
Peritectic Melting ◽  
Phase Compound ◽  
Optimum Reaction

The sintering temperature is played a vital role in the evolution of phase structure, microstructure, and the properties of the superconductor. In this study, the Gd0.9La0.1Ba1.95Sr0.05Cu3O7-d phase compound has been synthesized by the wet method using HNO3 as a solvent. The samples were divided into two groups. The first sample was calcined at 400 °C for 2 hours + 500 °C for 2 hours + 600 °C for 6 hours. The second sample treated by the same process and then continued by heating at 900 °C for 15 minutes. The effect of the calcination temperature for the synthesis of Gd0.9La0.1Ba1.95Sr0.05Cu3O7-d bulks was investigated using the DTA-TG method. The results showed that the optimum reaction temperature for the formation of Gd0.9La0.1Ba1.95Sr0.05Cu3O7-d phase was 938 °C. The additional heating temperature e.g. 900 °C for 15 minutes on the calcination process can reduce the optimum formation temperature of Gd0.9La0.1Ba1.95Sr0.05Cu3O7-d compounds by 20 °C. The peritectic melting reaction temperatures of the sample without the addition of heating and with the addition of heating at temperature 900 °C for 15 minutes are 1032°C and 1035°C, respectively. The melting temperatures of both samples are 1164 °C and 1200 °C.

Pengaruh Penambahan Perekat Tepung Sagu dan Bentonit Terhadap Briket Limbah Arang Tempurung Kelapa

2016 ◽  
Vol 9 (1) ◽  
pp. 13-19
Author(s):  
Petrus Patandung
Keyword(s):  
Data Analysis ◽  
Moisture Content ◽  
Research Method ◽  
Design Research ◽  
Corn Starch ◽  
Heating Temperature ◽  
Calorific Value ◽  
Coconut Shell ◽  
Descriptive Data ◽  
Fuel Design

The effect of the addition of corn starch adhesive and bentonite to waste coconut shell charcoal briquettes research are purposed to determine the effect of corn starch adhesive and bentonite waste coconut shell charcoal briquette with the variation of the concentration of corn starch and bentonite so it can produce briquettes that qualify as fuel. Design research method using the addition of corn starch and bentonite 3:2; 2,5:2,5 and 2:3 (w /w) g by using coconut shell charcoal waste 5kg with descriptive data analysis, while treatment has 5 (five) times repetation. The results showed that the range: 4.20 to 4.40% moisture content, ash 9.24 to 9.80%, from 0.63 to 0.68 density type g/m³, the missing part on the heating temperature of 950 °C 13,77 to 13.92% and the calorific value of 6728.15 to 6729.61 cal/g. Briquettes obtained can be used as an alternative fuel, using 700 g briquettes can cooked 5 (five) liters water, and it’s takes 45-56 minutes. The analysis showed that the best treatment is using corn starch and bentonite is 3:2, which produces a high enough caloric value is equal to 6729.61 cal/g.ABSTRAKPenelitian pengaruh penambahan perekat tepung sagu dan bentonit terhadap briket limbah arang tempurung kelapa dilakukan dengan tujuan untuk mengetahui pengaruh perekat tepung sagu dan bentonit briket limbah arang tempurung kelapa dengan variasi konsentrasi tepung sagu dan bentonit sehingga dihasilkan briket yang memenuhi syarat sebagai bahan bakar. Metode rancangan penelitian adalah penambahan tepung sagu dan bentonit 3:2; 2,5:2,5 dan 2:3 (b/b) gram  dengan menggunakan limbah arang tempurung kelapa sebanyak 5 kg dengan data dianalisis secara deskriptif, sedangkan ulangan dilakukan sebanyak 5 (lima) kali. Hasil penelitian menunjukkan kisaran: kadar air 4,20-4,40%, abu 9,24-9,80%, kerapatan jenis 0,63-0,68 g/m³, bagian yang hilang pada pemanasan suhu 950°C 13,77-13,92% dan  nilai kalori 6728,15-6729,61 kal/g.  Briket yang diperoleh dapat digunakan sebagai bahan bakar alternatif, dengan menggunakan 700 gr briket pemasakan air 5 (lima) liter  memerlukan waktu 45-56 menit. Perlakuan terbaik diperoleh dengan perbandingan tepung sagu dan bentonit yaitu 3:2 yang menghasilkan nilai kalori yang cukup tinggi adalah sebesar 6729,61 kal/g. Kata kunci : Tempurung kelapa,limbah arang, tepung sagu, bentonit, briket

Perfluorocarbon (PFC) Generation at Primary Aluminum Smelters

2013 ◽  
pp. 1015-1023 ◽  
Author(s):  
Bernard P. Léber ◽  
Alton T. Tabereaux ◽  
Jerry Marks ◽  
Brian Lamb ◽  
Touche Howard ◽  
...  
Keyword(s):  
Primary Aluminum ◽  
Aluminum Smelters

Flakt SO2 Scrubbing Technology for Primary Aluminum Smelters

JOM ◽  
1984 ◽  
Vol 36 (2) ◽  
pp. 57-62 ◽  
Author(s):  
Erik Keul ◽  
Avrid Tokerud
Keyword(s):  
Primary Aluminum ◽  
Aluminum Smelters

scholarly journals Bamboo Fiber and Sugarcane Skin as a Bio-Briquette Fuel

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2186 ◽  
Author(s):  
Anna Brunerová ◽  
Hynek Roubík ◽  
Milan Brožek
Keyword(s):  
Quality Indicators ◽  
Calorific Value ◽  
Bamboo Fiber ◽  
Waste Biomass ◽  
Fuel Production ◽  
Central Vietnam ◽  
Agriculture Residues ◽  
Mechanical Durability ◽  
Overall Evaluation ◽  
High Level

The present study deals with the issue of bio-briquette fuel produced from specific agriculture residues, namely bamboo fiber (BF) and sugarcane skin (SCS). Both materials originated from Thừa Thiên Huế province in central Vietnam and were subjected to analysis of their suitability for such a purpose. A densification process using a high-pressure briquetting press proved its practicability for producing bio-briquette fuel. Analysis of fuel parameters exhibited a satisfactory level of all measured quality indicators: ash content Ac (BF—1.16%, SCS—8.62%) and net calorific value NCV (BF—16.92 MJ∙kg−1, SCS—17.23 MJ∙kg−1). Equally, mechanical quality indicators also proved satisfactory; bio-briquette samples’ mechanical durability DU occurred at an extremely high level (BF—97.80%, SCS—97.70%), as did their bulk density ρ (BF—986.37 kg·m−3, SCS—1067.08 kg·m−3). Overall evaluation of all observed results and factors influencing the investigated issue proved that both waste biomass materials, bamboo fiber and sugarcane skin, represent suitable feedstock materials for bio-briquette fuel production, and produced bio-briquette samples can be used as high-quality fuels.

scholarly journals Impact of Mushroom Pleurotus tuber-regium (Rumph. ex) Fr. Extract on Lipid Profile and Testosterone of Rat

2020 ◽  
Vol 8 (11) ◽  
pp. 2268-2276
Author(s):  
Sukumar Danadapat ◽  
Manoj Kumar ◽  
Rakesh Ranjan ◽  
Manoranjan Prasad Sinha
Keyword(s):  
Total Cholesterol ◽  
Ldl Cholesterol ◽  
Calorific Value ◽  
Hdl Cholesterol ◽  
Diet Supplement ◽  
In Vivo Analysis ◽  
High Level ◽  
Male Reproductive Health

Pleurotus tuber-regium has been used as fodder and traditionally used as medicinal supplement. The aim of this study was to screen in vitro proximate biochemical composition and nutritional potentiality of P. tuber-regium extract for further in vivo analysis of impact of the extract on serum lipid and testosterone profile of rats. Total cholesterol, HDL cholesterol, LDL cholesterol were measured photometrically. Testosterone was measured by chemiluminescence immune assay. P. tuber-regium extract contains different biochemicals such as proteins, carbohydrates, tannins, flavonoids, phenols etc. and showed highly quantified calorific value (297.89±1.92 calori/100g). Acute toxicity test showed no mortality and toxic behavioural symptoms. Significant decrease in total cholesterol (75.52±0.39mg/dL), LDL cholesterol (34.58±1.69mg/dL) and triglyceride (81.31±1.25) were observed in rat group treated with 200mg/kg dose of extract. 400mg/kg dose of extract showed higher efficacy than 200mg/kg dose of extract and significantly decreased total cholesterol (72.25±1.11mg/dL), LDL cholesterol (26.37±1.21mg/dL) and triglyceride (69.42±0.72). The extract showed testosterone enhance efficacy. 400mg/kg dose of extract showed high level testosterone (178.96±0.68 ng/dL) enhance efficacy than 200mg/kg dose (174.64±0.64ng/dL). Due to hypocholesterolaemia and testosterone elevating properties of P. tuber-regium extract, it can be said that, mushroom P. tuber-regium can be consumed as healthy diet supplement to maintain cholesterol level and to maintain good male reproductive health.

scholarly journals Types and Composition of Biomass in Biocoke Synthesis with the Coal Blending Method

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6570
Author(s):  
Erlina Yustanti ◽  
Endarto Yudo Wardhono ◽  
Anggoro Tri Mursito ◽  
Ali Alhamidi
Keyword(s):  
Blast Furnace ◽  
Heating Temperature ◽  
Calorific Value ◽  
Water Medium ◽  
Fixed Carbon ◽  
Coking Coal ◽  
Coal Mixture ◽  
Blending Method ◽  
Coal Blending ◽  
Green Sample

The steelmaking industry requires coke as a reducing agent, as an energy source, and for its ability to hold slag in a blast furnace. Coking coal as raw coke material is very limited. Studying the use of biomass as a mixture of coking coal in the synthesis of biocoke is necessary to reduce greenhouse gas coal emissions. This research focuses on biomass and heating temperature through the coal blending method to produce biocoke with optimal mechanical properties for the blast-furnace standard. The heating temperature of biomass to biochar was evaluated at 400, 500, and 600 °C. The blending of coking coal with biochar was in the compositions of 95:5, 85:15, and 75:25 wt.%. A compacting force of 20 MPa was employed to produce biocoke that was 50 mm in diameter and 27 mm thick using a hot cylinder dye. The green sample was heated at 1100 °C for 4 h, followed by quenching with a water medium, resulting in dense samples. Increasing heating temperature is generally directly proportional to an increase in fixed carbon and calorific value. Biocoke that meets several blast-furnace criteria is a coal mixture with coconut-shell charcoal of 85:15 wt.%. Carbonization at 500 °C, yielding fixed carbon, calorific value, and compressive strength, was achieved at 89.02 ± 0.11%; 29.681 ± 0.46 MJ/kg, and 6.53 ± 0.4 MPa, respectively. This product meets several criteria for blast-furnace applications, with CRI 29.8 and CSR 55.1.

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