Evaluation of Physical and Chemical Properties of South African Waste Foundry Sand (WFS) for Concrete Use

Iloh, Patrick; Fanourakis, G.C.; Ogra, Aurobindo

doi:10.3390/su11010193

Cited by 18 publications

(27 citation statements)

References 31 publications

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“…The results already reported in the literature indicate that spent foundry sands are generally sub-angular to round [4,7,9,10]. They present a fine and uniform size distribution as proven by the results obtained for about fifty spent foundry sands [4,7,[10][11][12][13][14][15][16][17][18]. The majority of the particles are no larger than 500 µm [7,11,17], and their maximal diameter is generally less than 2 mm [10,17,18].…”

Section: Introductionmentioning

confidence: 64%

Comprehensive Characterization of Spent Chemical Foundry Sand for Use in Concrete

et al. 2021

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The foundry industry generates large amounts of spent foundry sands, which are stored, available for recovery in other industrial sectors but unfortunately poorly exploited. Different authors have studied the possibility of recovering them in concretes, which would also allow production of more sustainable cementitious materials. The variability of their results highlights the importance of a better understanding of the potential influential parameters of the by-products. Unfortunately, exhaustive characterizations of the materials are rarely performed, especially for chemically bound foundry sands. This article presents a case study for the recovery of a spent chemical foundry sand with an exhaustive physicochemical characterization of the by-product and an analysis of its influence on the workability and mechanical strengths of cementitious materials. The tests recommended by the European standard for aggregates for concrete confirmed the suitability of the by-product. Associated with additional chemical tests (scanning electron microscopy, X-ray fluorescence, X-ray diffraction, etc.) as well as metallic particles characterization, they highlighted possible influential parameters. The workability and mechanical resistance tests carried out on mortars and concretes confirmed the influence of the fineness of the by-product associated with other parameters. Its use at a substitution rate of 30% results in a strength class C 30/37 concrete.

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Section: Introductionmentioning

confidence: 64%

Comprehensive Characterization of Spent Chemical Foundry Sand for Use in Concrete

et al. 2021

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“…According to Johnson [35], the pH of WFS is dependent on the type of metal cast, the binder used, and it normally ranges between 4 and 8. In the study conducted by [36], on the evaluation of physical and chemical properties of South Africa waste found sand, 39 WFS from steel, iron, and aluminum were studied and the pH value ranging from 6.7 to 10.2 was reported [36]. The pH was found to be 9.10, indicating that the sand is basic and within the range of reported WFS pH.…”

Section: Resultsmentioning

confidence: 97%

“…However, in this study, the smallest DFS particle size investigated resulted in the lowest strength of 2.9 MPa. Figure 10 shows the microstructure of WFS and DFS geopolymers cured at 80 °C for 72 h. WFS is made up of angular, sub-angular, and round particle shapes [36]. The mechanism of geopolymerization is seen from time-based SEM analysis.…”

Section: Effect Of Psd On the Ucsmentioning

confidence: 99%

Recovery of Silicon Dioxide from Waste Foundry Sand and Alkaline Activation of Desilicated Foundry Sand

Mashifana

Sithole

2020

J. Sustain. Metall.

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This study was conducted to recover silica (desilication) as a valuable metalloid from waste foundry sand (WFS) by a leaching process and to find application for desilicated foundry sand (DFS). The leaching time applied was 5 h; 3 M of potassium hydroxide (KOH) was used as a leaching reagent. The agitation speed of 200 rpm and the liquid/solid ratio of 25 were found to be the best conditions for optimum leaching results. A geopolymer from DFS was developed by using NaOH as an alkaline activator. The results obtained showed that the optimum conditions for the synthesis of a geopolymer were 15 M NaOH, 150 µm DFS particle size, and a curing temperature of 80 ℃ for 72 h. The geopolymer strength development was due to the formation of Phillipsite and Kalsilite as new hydration products. At the optimum alkaline solution concentration, the highest unconfined compressive strength (UCS) of 4.8 MPa was achieved. The developed geopolymer met the minimum strength requirements for load bearing material. This study provides an innovative and novel solution for the beneficiation of spent foundry sand and the recovery of a valuable metalloid, resulting to zero waste generation. Graphical Abstract

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“…This material deposited along rivers (quartz pebbles mixed with washed sand) has been used in concrete for the production of works of art (bridges-road-rail crossings) and their supporting structures (foundations, pillars, and beams) [38]. There is also the possibility of transforming quartz through size reduction for use as a fine aggregate (sand) or as an additive for the production of high-performance concrete (CAD) [39][40][41]. Once the material has been characterized for use as an input in concrete and mortar, through the performance of laboratory tests, it may then be classified as an aggregate or additive.…”

Section: Mining Takes Place In the Open And Consists Of Exploration And Processing Activitiesmentioning

confidence: 99%

Quartz Mining Waste for Concrete Production: Environment and Public Health

et al. 2021

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Brazil, one of the largest ore producers in the world, holds 95% of the world’s quartz reserves. The aim of this research is to enhance mitigation measures in quartz ore exploration common in the Serra do Espinhaço Meridional region through the specific study of a mining venture. The three (3) phases of the study were: (1) characterization of the project under study and evaluation of the impacts generated; (2) evaluation of the economic feasibility of using the waste as a coarse aggregate for concrete production; (3) evaluation of the technical feasibility of reusing this waste through analysis of compressive strength. The results of the study show potential negative impacts on occupational health from the piles of disposed waste, specifically silicosis, caused by silica dust dispersed in the air. In the economic analysis, a decrease of 49.05% was verified in coarse aggregate cost through the use of the residue. The compressive strength of the concrete was 26.80 MPa when quartz residue was used and 29.2 MPa when limestone was used. The quartz residue generated by the venture can be reused as aggregate for the production of concrete, generating improvements in environmental and health aspects.

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Evaluation of Physical and Chemical Properties of South African Waste Foundry Sand (WFS) for Concrete Use

Cited by 18 publications

References 31 publications

Comprehensive Characterization of Spent Chemical Foundry Sand for Use in Concrete

Comprehensive Characterization of Spent Chemical Foundry Sand for Use in Concrete

Recovery of Silicon Dioxide from Waste Foundry Sand and Alkaline Activation of Desilicated Foundry Sand

Quartz Mining Waste for Concrete Production: Environment and Public Health

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