The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide

Li, Jinchunzi; Chen, Zhonglin; Shen, Jimin; Wang, Binyuan; Fan, Leitao

doi:10.1016/j.chemosphere.2015.04.021

Cited by 24 publications

(10 citation statements)

References 34 publications

(33 reference statements)

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“…Occasionally, when a soluble layer distributes on the surface, surface wash‐off phenomenon may occur. Indeed, most of the soluble components in the soluble layer are dissolved during the initial phase of the leaching experiment which results in a slope close to 0 …”

Section: Resultsmentioning

confidence: 99%

“…Indeed, most of the soluble components in the soluble layer are dissolved during the initial phase of the leaching experiment which results in a slope close to 0. 35,37 Sr cumulative release from different Sr-contained products are tested in the deionized water and presented in Figure 13. Samples treated at 800°C and 1000°C both have slopes close to 0.5 (0.51 at 800°C and 0.45 at 1000°C, respectively), indicating diffusion is the dominated mechanism in this temperature zone.…”

Section: Probing the Leaching Behaviors Of Srmentioning

confidence: 99%

See 1 more Smart Citation

Immobilization behavior of Sr in geopolymer and its ceramic product

Lou

Jia

et al. 2019

J Am Ceram Soc

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To date, geopolymer has emerged as a promising and inexpensive precursor with potential application in trapping hazardous elements via physical encapsulation or chemical bonding. In this work, different high‐temperature products derived from Sr‐contained geopolymer precursors were prepared. Different to conventional hazardous elements that immobilized in the geopolymer precursor, which show decreasing leaching rates after high‐temperature treatments, leaching rates of Sr in the resulting high‐temperature products first increase and then decrease with the increasing heating temperature. Herein, we first shed light on the underlying reasons of such temperature‐dependent leaching behaviors by investigating effects of heating temperature on the phase composition, microstructure, and immobilization mechanism. Moreover, a novel immobilization strategy has been proposed based on the blocking effect of formed nepheline structures at 1200°C. Using this strategy, the leaching rate of Sr reduced to 5.82 × 10−7g cm−2 d−1 in the deionized water.

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Section: Resultsmentioning

confidence: 99%

Section: Probing the Leaching Behaviors Of Srmentioning

confidence: 99%

Immobilization behavior of Sr in geopolymer and its ceramic product

Lou

Jia

et al. 2019

J Am Ceram Soc

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“…If it is not recycled or reused, not only are resources wasted, but serious pollution of the environment results, which will have a serious impact on the health of the surrounding residents because of the toxic Cr 6+ content of the slag [ 9 , 10 , 11 ]. At present, the treatment method for chromium slag is mostly landfill after reduction or solidification, but there are still potential environmental hazards and resource waste to consider [ 12 ]. Thus, it is valuable to explore further treatment methods for chromium slag.…”

Section: Introductionmentioning

confidence: 99%

Enrichment Characteristics of Cr in Chromium Slag after Pre-Reduction and Melting/Magnetic Separation Treatment

Wang

et al. 2021

Materials

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Concentrating the chromium in chromium slag and improving the chromium–iron ratio is beneficial for the further utilization of chromium slag. In this paper, chromium slag obtained from a chromite lime-free roasting plant was used as the raw material. Pellets made of the chromium slag and pulverized coal were reduced at different pre-reduction temperatures and then separated by a melting separation process or magnetic separation process, respectively. The mass and composition of the metallized pellets before separation, along with the alloy and tail slag after separation, were comprehensively analyzed. The experimental results showed that the output yield of alloy, iron recovery rate, and chromium content in the alloy were all higher when using melting separation than when using magnetic separation, because of the further reduction during the melting stage. More importantly, a relatively low pre-reduction temperature and selection of magnetic separation process were found to be more beneficial for chromium enrichment in slag; the highest chromium–iron ratio in tail slag can reach 2.88.

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“…Today, due to its low cost, blast furnace slag (BFS) is commonly used as a binder to solidify/stabilize arsenic‐bearing sludge or waste . By the addition of SO 4 2− and Cl − , ettringite and Friedel's salt are found in BFS slag‐based binder, respectively .…”

Section: Introductionmentioning

confidence: 99%

Comparison of arsenic immobilization properties among calcium silicate hydrate, ettringite, and friedel's salt in a slag‐based binder

Min

Liu

Chai

et al. 2018

Env Prog and Sustain Energy

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Calcium silicate hydrate (CSH), ettringite, and Friedel's salt, three kinds of hydration products reported in cement‐based or slag‐based binder, are recognized as having significant roles in the solidification/stabilization (S/S) of heavy metals in wastes. However, which of these products has an excellent S/S property for arsenic has yet to be elucidated. Therefore, in this study, slag‐based binders with CSH, ettringite, and Friedel's salt as the main hydration products are prepared. Then, sodium arsenate is introduced into the slag‐based binder to prepare the matrices containing arsenic. The immobilization properties of arsenic in the three types of matrices are compared via an unconfined compressive strength (UCS) test, toxicity characteristic leaching procedure (TCLP), and sequential extraction procedure analysis. The results show that sodium arsenate decreases the UCS of the three types of matrices by retarding the hydration rate of the slag‐based binder. The Friedel's salt matrices have greater long‐term strength than the other two matrices. The arsenic leaching concentrations for the Friedel's salt matrices are lower than those for the other two matrices at the same initial arsenic concentration. Moreover, the fraction of arsenic in a stable state is greater in the Friedel's salt matrices than in the CSH and ettringite matrices. Consequently, in a slag‐based binder system, matrices containing Friedel's salt phase exhibit a higher UCS, excellent arsenic immobilization capacity, and more arsenic in a residual state than those containing the other two types of matrices. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S422–S428, 2019

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The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide

Cited by 24 publications

References 34 publications

Immobilization behavior of Sr in geopolymer and its ceramic product

Immobilization behavior of Sr in geopolymer and its ceramic product

Enrichment Characteristics of Cr in Chromium Slag after Pre-Reduction and Melting/Magnetic Separation Treatment

Comparison of arsenic immobilization properties among calcium silicate hydrate, ettringite, and friedel's salt in a slag‐based binder

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