Recycling high volume Fe-rich fayalite slag in blended alkali-activated materials: Effect of ladle and blast furnace slags on the fresh and hardened state properties

Adediran, Adeolu Adesoji; Yliniemi, Juho; Lemougna, Patrick N.; Perumal, Priyadharshini; Illikainen, Mirja

doi:10.1016/j.jobe.2022.105436

Cited by 5 publications

(3 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This fact is favorable for the use of, for example, flotation to obtain a concentrate of non-ferrous metals [18,60]. The residue after non-ferrous metal extraction can effectively be used in the construction industry [27][28][29].…”

Section: Leaching Slag Testmentioning

confidence: 99%

“…The works [18,[22][23][24][25] provide extensive reviews on the known methods of utilizing slags from various metallurgical industries. Thus, a perspective direction for slag utilization could be their use in the construction industry [17,[26][27][28][29][30]. However, the direct use of slags in this area leads to a total loss of non-ferrous metals, and a series of technological features of this type of resource, which differ from natural ones, are complicated.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Deep Processing of Dump Slag from the Copper-Nickel Industry

Kasikov

Shchelokova

Timoshchik

et al. 2023

Metals

View full text Add to dashboard Cite

This work proposes an environmentally safe and economically feasible method of waste copper-nickel production slag utilization (Kola Mining-Metallurgical Company, Nornickel, Kola Peninsula, Russia). This process involves the decomposition of slag by diluted solutions of sulfuric acid (7–10 wt.% H2SO4) with a transfer in a solution of more than 70% silicon, 77% iron and 78% magnesium, and a concentration of non-ferrous metals in the residue (~70%). Copper ions were used in the leaching stage to prevent the release of hydrogen sulfide into the working atmosphere. Dehydration of the solution, followed by washing of water-soluble sulphates from silica, was carried out to separate silica from the leaching solution. The dehydration temperature effect on the silica structural characteristics was determined. The possibility of recovering non-ferrous metals from solutions after silica extraction by precipitation, in the form of copper cementite, and the sum of nickel and cobalt sulfides, was evaluated. Pigment-grade iron dioxide, magnesium sulphate and aluminium hydroxide were obtained by dehydration of the solution after extraction of base metals, calcination and other operations. Sulfuric acid leaching resulted in the disclosure of sulfide grains encapsulated in ferrosilicate, which is a favorable factor for flotation. The depleted residue can be successfully used in the construction industry.

show abstract

Section: Leaching Slag Testmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Deep Processing of Dump Slag from the Copper-Nickel Industry

Kasikov

Shchelokova

Timoshchik

et al. 2023

Metals

View full text Add to dashboard Cite

show abstract

“…Blast furnace slag is often combined with other co-products (waste) for the manufacture of alkali-activated materials, such as fly ash [27], washing aggregate sludge [29]; boron waste [30]; sludge waste [31,32]. Slags of specific compositions (Fe-rich fayalite slag (FS), ferronickel slag (FNS)) have also been the subject of investigations with the aim of developing alkali-activated materials [33,34]. The effects of ion species and alkalinity are studied; the results showed that more C-A-S-H gels were produced than the crystalline phases at lower activator concentration, while more crystalline phases formed at high concentration [34].…”

Section: Introductionmentioning

confidence: 99%

Valorization of a Steel Industrial Co-Product for the Development of Alkali-Activated Materials: Effect of Curing Environments

Sarri

Oualit

Kennouche

2023

Advances in Materials Science

View full text Add to dashboard Cite

While natural resources are becoming scarce and climate change is accelerating, the recovery and recycling of wastes and by-products is an effective way to deal with the economic and ecological constraints of recent decades. The valorization of industrial by-products in civil engineering is a common practice either by their incorporation during the manufacture of Portland cements or as a partial replacement of cement during the production of concrete. The present work aims to develop waste-based alkali-activated materials WAAMs intended for civil engineering applications as a potential alternative to cement-based materials. A steel industrial by-product called commonly granulated blast furnace slag GBFS was used alone as a solid CaO-rich precursor; two alkaline activators such us sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) were used separately for the production of two-part alkali-activated materials. Besides the microstructure analysis of the hardened samples, the influence of activator/precursor mass ratio, NaOH molarity, and two curing environments (Room temperature and 60°C) on the compressive strength, water accessible porosity, mass loss, and drying shrinkage were assessed. The results showed that a high Liquid/Solid ratio leads to a decrease in the compressive strength of the samples, while high NaOH molarity significantly improves the mechanical properties by reducing the porosity of the specimens. Moreover, alkaline silicate activator provides higher compressive strengths compared to the alkaline hydroxide activator, especially when the samples were cured at room temperature where a maximum 28days-compressive strength value of 105.28 MPa was achieved. For the samples activated using sodium hydroxide solution, the results revealed that their curing at 60°C promotes obtaining high initial-compressive strengths (7 days) before decreasing subsequently as a function of the curing time. As an indication, at high alkaline concentration (NaOH = 9M), a mechanical strength decline of 21% was recorded between a curing time of 7 to 28 days. Moreover, curing at 60°C induced high porosity, significant mass loss and high drying shrinkage. SEM analysis highlighted a dense, homogeneous microstructure without apparent defects, in particular for the samples where the alkali silicate activator was used.

show abstract