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Alexander Gorokhovsky - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of high strength ceramic composites in the system of potassium titanate Metallurgical Slag
Ceramics International, 2015Co-Authors: Alexander Gorokhovsky, J I Escalantegarcia, Denis Kuznetsov, E Sanchezvaldes, I N BurmistrovAbstract:Abstract Ceramic composites based on different mixtures of the powdered Slags from silicomanganese manufacturing and synthetic potassium titanates, were produced and investigated. Green bodies were fabricated by uni-axial compression at 35 and 196 MPa. The sinters were obtained by one-stage (1100 °C/1 h) or two-stage (800 °C/1 h and 1100 °C/1 h) thermal regimes. The best mechanical properties were achieved for conditions of 33 wt% of Slag, compressed under 196 MPa and treated by the two-stage regime of sintering. Structural investigation of the processes taking place in the produced ceramic materials was carried out by scanning electron microscopy and X-ray diffraction. The resulting products were characterized by a gradient phase composition constituted by perovskite, leucite, potassium hexatitanate, pyrophanite-ilmenite solid solutions, hollanadite-like and pyroxene-like crystalline phases as well as glassy phase of varied chemical composition. The mechanism of the sintering processes was also characterized.
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inorganic wastes in the manufacture of glass and glass ceramics quartz feldspar waste of ore refining Metallurgical Slag limestone dust and phosphorus slurry
Journal of the American Ceramic Society, 2004Co-Authors: Alexander Gorokhovsky, Vladilen Gorokhovsky, J I Escalantegarcia, Dmitrii V. MescheryakovAbstract:This work presents the results of an investigation on producing diopside glass-ceramic materials based on various combinations of quartz-feldspar waste from ore refining and limestone dust. Other industrial wastes were added to contribute as nucleation agents; when the concentration of the latter was insufficient, they were added in the pure state. Additionally, relatively high concentrations of alkalis were used to accelerate glass melting. Low-cost materials with promising exploitation properties were produced. A two-stage regime of crystallization of the basic glass composition was determined, including nucleation at 720°C and crystal growth at 950°C. Local environmental regulations must be considered for the selection of the type of admixtures and the combination of wastes.
Wei Gao - One of the best experts on this subject based on the ideXlab platform.
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influence of calcium hydroxide addition on arsenic leaching and solidification stabilisation behaviour of Metallurgical Slag based green mining fill
Journal of Hazardous Materials, 2020Co-Authors: Yuying Zhang, Wei Gao, Siqi Zhang, Ke Wang, Xiaohui HuangAbstract:Abstract In this study, Metallurgical-Slag-based binder (MSB) with different dosages of calcium hydroxide (CH) was mixed with high-arsenic-containing mine tailings (HAMT) to form green mining fill samples (GMFs) for As solidification/stabilisation (S/S). The As leaching characteristics of the GMFs were evaluated using pH-dependent leaching tests, semi-dynamic leaching tests and toxicity leaching tests. The effective diffusion coefficient (De) decreased from 6.98 × 10−14 to 5.90 × 10−15 cm2/s and the leachability index (LI) increased from 13.53 to 14.73 after 3 wt.% CH was added to the GMFs. The GMFs containing 0 wt.% CH (GMF-0C) and those containing 3 wt.% CH (GMF-3C) reached pH = 2 with acid addition amounts of 9.0 meq/g-dry and 9.3 meq/g-dry at 90 d curing time, and the maximum As leaching concentrations of GMF-0C and GMF-3C reached 10.47 mg/L and 7.47 mg/L, respectively, indicating that GMF-3C exhibited better acid neutralisation and As retention capacities than GMF-0C. Further, a Tescan Integrated Mineral Analyser (TIMA) was used to analyse the dominant hydration products of GMF-3C, which revealed that calcium silicate hydrate, CASH, ettringite and zeolite phases represented approximately 22.5 wt.% of the products. These results provide an understanding regarding the safe large-scale utilisation of GMFs.
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investigation into the semi dynamic leaching characteristics of arsenic and antimony from solidified stabilized tailings using Metallurgical Slag based binders
Journal of Hazardous Materials, 2020Co-Authors: Wei Gao, Yuying Zhang, Tengyu ShiAbstract:Abstract The leaching characteristics of Metallurgical Slag-based binders (MSB) solidified/stabilized tailings containing arsenic (As) and antimony (Sb), were investigated via a series of semi-dynamic leaching tests using three kinds of leachant, for the simulation of actual leaching conditions. The effectiveness of solidification/stabilization (S/S) treatment was evaluated by measuring the observed diffusion coefficients (Dobs). It was found that MSB efficiently prevented As and Sb leaching, providing Dobs values in the range of 10−15 to 10−13 cm2/s and 10−11 to 10−9 cm2/s, respectively, with the exception that the leaching mechanism of As was dissolution rather than diffusion under acetic acid leaching conditions. Physical encapsulation was found to be the dominant mechanism for Sb immobilization, while the dominant mechanism of As immobilization was precipitation in the monolithic MSB S/S treated tailings (MST). Results showed that the concentrations of leached As, Sb, Ca and Si, were affected by leachant pH and total acidity as well as the MSB constituent ratio. The effect of these parameters may be attributed to the stability of hydration products and their influence on the buffering capacity and structure of matrices, and the leachant pH and total acidity having the greatest influence on leaching characteristics.
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immobilisation of high arsenic containing tailings by using Metallurgical Slag cementing materials
Chemosphere, 2019Co-Authors: Yuying Zhang, Siqi Zhang, Qihui Yan, Wei GaoAbstract:Abstract The mixture of finely ground blast furnace Slag (BFS), basic oxygen furnace (BOF) steel Slag (SS), and flue gas desulfurisation (FGD) gypsum could be used as cement to solidify heavy metals. In this study, these cementitious materials were combined with high-arsenic-containing tailings to form cemented backfill material (CBM). The results indicated that the optimal design of CBM was that of specimen CBM2 which showed good early strength (10.09 MPa) at a curing age of 3 days containing 60% BF Slag, 30% SS, and 10% gypsum. And the arsenic leaching concentration of CBM2 at a curing age of 7 days and 28 days were both less than the limits specified in standards for drinking water quality (Chinese Standard GB 5749-2006). The predominant hydration products of CBM2 contained rod-like ettringite and amorphous C–S–H gel both of which promote arsenic solidification.
Yuying Zhang - One of the best experts on this subject based on the ideXlab platform.
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influence of calcium hydroxide addition on arsenic leaching and solidification stabilisation behaviour of Metallurgical Slag based green mining fill
Journal of Hazardous Materials, 2020Co-Authors: Yuying Zhang, Wei Gao, Siqi Zhang, Ke Wang, Xiaohui HuangAbstract:Abstract In this study, Metallurgical-Slag-based binder (MSB) with different dosages of calcium hydroxide (CH) was mixed with high-arsenic-containing mine tailings (HAMT) to form green mining fill samples (GMFs) for As solidification/stabilisation (S/S). The As leaching characteristics of the GMFs were evaluated using pH-dependent leaching tests, semi-dynamic leaching tests and toxicity leaching tests. The effective diffusion coefficient (De) decreased from 6.98 × 10−14 to 5.90 × 10−15 cm2/s and the leachability index (LI) increased from 13.53 to 14.73 after 3 wt.% CH was added to the GMFs. The GMFs containing 0 wt.% CH (GMF-0C) and those containing 3 wt.% CH (GMF-3C) reached pH = 2 with acid addition amounts of 9.0 meq/g-dry and 9.3 meq/g-dry at 90 d curing time, and the maximum As leaching concentrations of GMF-0C and GMF-3C reached 10.47 mg/L and 7.47 mg/L, respectively, indicating that GMF-3C exhibited better acid neutralisation and As retention capacities than GMF-0C. Further, a Tescan Integrated Mineral Analyser (TIMA) was used to analyse the dominant hydration products of GMF-3C, which revealed that calcium silicate hydrate, CASH, ettringite and zeolite phases represented approximately 22.5 wt.% of the products. These results provide an understanding regarding the safe large-scale utilisation of GMFs.
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investigation into the semi dynamic leaching characteristics of arsenic and antimony from solidified stabilized tailings using Metallurgical Slag based binders
Journal of Hazardous Materials, 2020Co-Authors: Wei Gao, Yuying Zhang, Tengyu ShiAbstract:Abstract The leaching characteristics of Metallurgical Slag-based binders (MSB) solidified/stabilized tailings containing arsenic (As) and antimony (Sb), were investigated via a series of semi-dynamic leaching tests using three kinds of leachant, for the simulation of actual leaching conditions. The effectiveness of solidification/stabilization (S/S) treatment was evaluated by measuring the observed diffusion coefficients (Dobs). It was found that MSB efficiently prevented As and Sb leaching, providing Dobs values in the range of 10−15 to 10−13 cm2/s and 10−11 to 10−9 cm2/s, respectively, with the exception that the leaching mechanism of As was dissolution rather than diffusion under acetic acid leaching conditions. Physical encapsulation was found to be the dominant mechanism for Sb immobilization, while the dominant mechanism of As immobilization was precipitation in the monolithic MSB S/S treated tailings (MST). Results showed that the concentrations of leached As, Sb, Ca and Si, were affected by leachant pH and total acidity as well as the MSB constituent ratio. The effect of these parameters may be attributed to the stability of hydration products and their influence on the buffering capacity and structure of matrices, and the leachant pH and total acidity having the greatest influence on leaching characteristics.
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immobilisation of high arsenic containing tailings by using Metallurgical Slag cementing materials
Chemosphere, 2019Co-Authors: Yuying Zhang, Siqi Zhang, Qihui Yan, Wei GaoAbstract:Abstract The mixture of finely ground blast furnace Slag (BFS), basic oxygen furnace (BOF) steel Slag (SS), and flue gas desulfurisation (FGD) gypsum could be used as cement to solidify heavy metals. In this study, these cementitious materials were combined with high-arsenic-containing tailings to form cemented backfill material (CBM). The results indicated that the optimal design of CBM was that of specimen CBM2 which showed good early strength (10.09 MPa) at a curing age of 3 days containing 60% BF Slag, 30% SS, and 10% gypsum. And the arsenic leaching concentration of CBM2 at a curing age of 7 days and 28 days were both less than the limits specified in standards for drinking water quality (Chinese Standard GB 5749-2006). The predominant hydration products of CBM2 contained rod-like ettringite and amorphous C–S–H gel both of which promote arsenic solidification.
Aitolkyn Uali - One of the best experts on this subject based on the ideXlab platform.
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the active carbons modified by industrial wastes in process of sorption concentration of toxic organic compounds and heavy metals ions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2017Co-Authors: Shamshiya Amerkhanova, Rustam Shlyapov, Aitolkyn UaliAbstract:Abstract The results of investigation of active carbons, obtained from the pine waste (lat. Pinus sylvestris) by modifying phosphoric acid and industrial (Metallurgical Slag) wastes, are discussed. The structure, composition and properties of obtained sorbent have been investigated by using FT-IR-spectroscopy, elemental analysis, DTA/TGA, SEM. The iodine adsorption activity and adsorption values toward to some inorganic and organic pollutants of sorbent have been evaluated. Based on laboratory test results, it was established that the sorbent on the base of activated carbons prepared by chemical modification, followed by carbonization in the presence of Metallurgical Slag and water treatment, has a porous structure. It was shown that sorbent can be used in the processes of sorption concentration of phenol, chloroform, pyridine, aniline, and also heave metals ions from aqueous solutions.
Marta Bożym - One of the best experts on this subject based on the ideXlab platform.
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An assessment of pH-dependent release and mobility of heavy metals from Metallurgical Slag.
Journal of hazardous materials, 2019Co-Authors: Anna Król, Kamila Mizerna, Marta BożymAbstract:Abstract The paper presents the results obtained in pHstat leaching test and assesses the influence of pH changes and occurring processes on the release of heavy metals (Cd, Ni, Crtotal, Pb, Cu and Zn) from Metallurgical Slag in a zinc smelter. Additionally, the analysis of the potential maximum amount of element available for leaching and releasing in the batch leaching test was carried out. All the results of the leaching tests were compared with the total content of heavy metals in the material. In order to evaluate the chemical forms of elements, a sequential extraction study was also carried out. On the basis of test results obtained in pHstat test, a strong dependence of heavy metals leaching on the pH was found. The highest concentrations of the analysed elements were observed in acidic environment. For most metals, except for lead, an increase in the pH of the solution caused a decrease in their concentration. Lead showed an upward trend of release under alkaline conditions. A sharp increase of copper leaching at pH 10.5 was also observed. Based on the results of the study, cadmium can be considered the most mobile element from Metallurgical Slag. Chromium indicated the lowest degree of release.