Preparation and Fixation Ability for Pb2+ of Geopolymeric Material Based on Bayer Process Red Mud

2014 ◽  
Vol 1049-1050 ◽  
pp. 175-179 ◽  
Author(s):  
Xiang Li Xie ◽  
Peng Peng ◽  
Wen Feng Zhu ◽  
Lin Iang Wang
Keyword(s):  
Compressive Strength ◽  
Aqueous Phase ◽  
Red Mud ◽  
Bayer Process ◽  
Curing Method ◽  
Metakaolin Geopolymer

Geopolymeric material (geopolymer) was synthesized by casting and curing method using Bayer process red mud and metakaolin as starting materials. The fixation ability of the geopolymer for Pb2+ was studied by leaching method. The results shown that metakaolin played the role of aluminum and silicon donor during the initial strong alkaline aqueous phase. Red mud had principally the role of filler, increasing in this way the final compressive strength of the geopolymer. The compress strength of geopolymer curing 3 days from metakaolin and red mud mixture is 66MPa. The leaching concentration of Pb2+ from 50% red mud geopolymer is 0.891mg/L as the Pb2+ content in geopolymer is 2.5%; the metakaolin-red mud geopolymer has better Pb2+ fixation ability than metakaolin geopolymer.

scholarly journals Development of Red Mud Paver Blocks Prepared From Nuclear Power Plant

2020 ◽  
Vol 13 (1) ◽  
pp. 54-68
Author(s):  
A Jayaraman ◽  
V Senthilkumar
Keyword(s):  
Compressive Strength ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Portland Cement ◽  
Red Mud ◽  
Nuclear Power ◽  
Waste Material ◽  
Bayer Process ◽  
Test Results ◽  
The World

Red mud is a waste material generated by the Bayer Process widely used to produce alumina from bauxite throughout the world. The aim of the project is to say the possibility of replacing the Portland cement by red mud. Because it negatively affects the environment. To solve this problem, Portland cement was replaced up to 20% red mud by weight of cement. And evaluating its compressive strength of red mud paver tiles. This project examines the effects of red mud on the properties of hardened paver tile. The test results show that how its compressive strength becomes equivalent to normal paver tile without red mud content, it is concluded that optimum percentage of the replacement of cement by weight is found to be. By this percentage replacement we can have 15%strength is equal to the strength of normal paver tile.

Liquid-liquid extraction of succinate using a dicopper cryptate

2020 ◽  
Author(s):  
Riccardo Mobili ◽  
Sonia La Cognata ◽  
Francesca Merlo ◽  
Andrea Speltini ◽  
Massimo Boiocchi ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Visible Spectrum ◽  
Tca Cycle ◽  
Residual Concentration ◽  
Waste Products ◽  
Liquid Liquid Extraction ◽  
The Tca Cycle ◽  
Quantitative Extraction ◽  
Uv Visible

<div> <p>The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous phase, buffered at pH 7 with HEPES, into dichloromethane. A 1:1 extractant:anion adduct is obtained. Extraction can be easily monitored by following changes in the UV-visible spectrum of the dicopper complex in dichloromethane, and by measuring the residual concentration of succinate in the aqueous phase by HPLC−UV. Considering i) the relevance of polycarboxylates in biochemistry, as e.g. normal intermediates of the TCA cycle, ii) the relevance of dicarboxylates in the environmental field, as e.g. waste products of industrial processes, and iii) the recently discovered role of succinate and other dicarboxylates in pathophysiological processes including cancer, our results open new perspectives for research in all contexts where selective recognition, trapping and extraction of polycarboxylates is required. </p> </div>

The Influence of the Properties of the Material Used for Obtaining Geopolymers on Their Structure and Compressive Strength

2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Wheat Straw ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Complex Structure ◽  
Point Of View ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Straw Ash

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.

scholarly journals Evaluation of Chemical Variability of Cured Vanilla Beans (Vanilla tahitensis and Vanilla planifolia)

2009 ◽  
Vol 4 (10) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Christel Brunschwig ◽  
François Xavier Collard ◽  
Jean-Pierre Bianchini ◽  
Phila Raharivelomanana
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Dry Matter ◽  
Monounsaturated Fatty Acids ◽  
Vanilla Planifolia ◽  
Chemical Variability ◽  
Total Fatty Acids ◽  
Curing Method ◽  
Fatty Acid Compositions

In order to establish a chemical fingerprint of vanilla diversity, thirty samples of V. planifolia J. W. Moore and V. tahitensis G. Jackson cured beans from seven producing countries were examined for their aroma and fatty acid contents. Both fatty acid and aroma compositions were found to vary between vanilla species and origins. Vanillin was found in higher amounts in V. planifolia (1.7-3.6% of dry matter) than in V. tahitensis (1.0-2.0%), and anisyl compounds were found in lower amounts in V. planifolia (0.05%) than in V. tahitensis (1.4%-2.1%). Ten common and long chain monounsaturated fatty acids (LCFA) were identified and were found to be characteristic of the vanilla origin. LCFA derived from secondary metabolites have discriminating compositions as they reach 5.9% and 15.8% of total fatty acids, respectively in V. tahitensis and V. planifolia. This study highlights the role of the curing method as vanilla cured beans of two different species cultivated in the same country were found to have quite similar fatty acid compositions.

scholarly journals Assessing the role of bed sediments in the persistence of red mud pollution in a shallow lake (Kinghorn Loch, UK)

2017 ◽  
Vol 123 ◽  
pp. 569-577 ◽  
Author(s):  
Justyna P. Olszewska ◽  
Kate V. Heal ◽  
Ian J. Winfield ◽  
Lorna J. Eades ◽  
Bryan M. Spears
Keyword(s):  
Shallow Lake ◽  
Red Mud ◽  
Bed Sediments

scholarly journals Characterization and Comparison of Geopolymer Synthesized Using Metakaolin Bangka and Metastar as Precursors

2018 ◽  
Vol 67 ◽  
pp. 03022
Author(s):  
Sotya Astutiningsih ◽  
Dicky Tambun ◽  
Ahmad Zakiyuddin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Mechanical Test ◽  
Strength Test ◽  
Thermal Activity ◽  
Metallurgical Properties ◽  
Metakaolin Geopolymer ◽  
Kaolin Deposit

Various aluminosilicate material have been used as precursor for geopolymer. Geopolymer gets its strength from the polycondensation of silicate and alumina. Metakaolin, calcinated kaolin, is pozzolan with the highest alumina and silicate purity. Indonesia, especially Bangka Island, has a large amount of kaolin deposit that being sold at low price. This price could be increased ten times when being sold as metakaolin. This study aimed to compare mechanical and metallurgical properties of commercial metakaolin and Bangka kaolin which calcinated at 700°C. Both metakaolins reacted with NaOH and waterglass as the activator followed by curing at room temperature for 7, 14 and 28 days and elevated temperature of 60°C for 4, 12 and 24 hours. Mechanical properties will be examined by compressive strength and flexural strength test, while the metallurgical properties will be evaluated with SEM, and TAM. The results of the mechanical test will be used to determine which geopolymer will perform well with the microstructure and thermal activity to support the finding. These attempts will be done in order to improve the properties of Bangka metakaolin geopolymer superior to commercial metakaolin.

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