scholarly journals Grain Size Effect in Elution Test of Electric Arc Furnace Slag

2020 ◽  
Vol 10 (2) ◽  
pp. 477 ◽  
Author(s):  
Alessandro Riboldi ◽  
Giovanna Cornacchia ◽  
Marcello Gelfi ◽  
Laura Borgese ◽  
Annalisa Zacco ◽  
...  

In this paper we discuss the effects of deslagging practices and the size of electric arc furnace (EAF) slags on structural, microstructural, composition and leaching tests. The samples were collected from seven steelmakers located in Brescia (Lombardy Region, Italy). Nine granularity fractions of four samples were tested to evaluate the influence of the granularity on the leaching tests. The results showed that, in general, the release of the elements arises when the size of the particle decreases, except in one sample, in which vanadium and zinc displayed the opposite trend. X-ray diffraction results suggest that behavior may be ascribed to the effect of the grinding, which causes a different percentage of the phases in the various fractions. In conclusion, the possible effects of the size should also be carefully considered when defining new leaching test requirements for EAF slags.

2015 ◽  
Vol 752-753 ◽  
pp. 277-282 ◽  
Author(s):  
Wan Afnizan Wan-Mohamed ◽  
Rafidah binti Hamdan ◽  
Norzila Othman

Eutrophication as a result of uncontrolled phosphorus (P) concentration that is released in wastewater has emerged as a major problem nowadays. Treatment of P demands high costs specifically to its chemical and maintenance needs. A lot of efforts were undertaken to find the most economical material that can treat P such as Electric Arc Furnace Slag (EAFS), a by-product from steel industry and Limestone (LS), and a natural resource that can be easily obtained from sedimentary rock. Despite numerous study conducted previously, the mechanism of P removal between these two materials have not been explored yet in detail. Therefore, an experimental work had been designed to evaluate the performance of P removal mechanism between the EAFS and LS lab-scale filter systems which can offer the best removal in overall. In this study a column lab scale of vertical rock filters in 100 mm diameter × 400 mm height were constructed for both EAFS and LS filters. The observation period was conducted for 2.5 months utilizing synthetic phosphorus concentration of 25 mg/L as its initial concentration. Working condition of the experiment was adjusted at pH 4.5 to 7.5 under 26.8±0.64 °C. X-ray fluorescence (XRF) analysis was also performed in order to determine chemical composition of EAFS and LS media. Results revealed that EAFS showed a significant effect on the removal of P mechanism compared to the LS filter system. The highest removal of P for both filter systems were observed to achieve 90% (pH 5) in the EAFS compared to only 68% (pH 4.5) in the LS system. This may be associated with the dissolution of Ca, Fe and Al elements in the EAFS that promotes precipitation process and hence gave higher removal compared to the LS element (only Ca has the highest percentage = 91%). At lower pH (acidic) condition the soluble metal salts react with phosphate ion to form phosphate hydrolysis product thus promoting precipitation in the system. In conclusion, it is predicted that precipitation may occur within the filter systems predominantly in the EAFS filter as pH was change from acidic to alkaline (4.5 – 7.5) due to dissolved (Al3+, Ca2+, Fe3+) within the filter system. Nevertheless, it is recommended that future study should be carried out on the precipitates salts through X-ray diffraction (XRD) analysis so as the existence of phosphate and metal salts as a result of precipitation can be finally confirmed.


2022 ◽  
Vol 316 ◽  
pp. 125553
Author(s):  
Aratz Garcia-Llona ◽  
Vanesa Ortega-Lopez ◽  
Ignacio Piñero ◽  
Amaia Santamaría ◽  
Miquel Aguirre

2020 ◽  
Vol 159 ◽  
pp. 106644
Author(s):  
Ting Su ◽  
Rui Bian ◽  
Yu Chen ◽  
Suiyi Zhu ◽  
Yang Huo ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document