Chemical surface mechanisms in rapid solid-liquid separation of sludge from HD-sludge recycling of AMD (Horobetsu)

G. C. Badulis; C. Tokoro; H. Sasaki

Chemical surface mechanisms in rapid solid-liquid separation of sludge from HD-sludge recycling of AMD (Horobetsu)

G. C. Badulis^*, C. Tokoro, H. Sasaki

^*Corresponding author for this work

School of Creative Science and Engineering

Research output: Contribution to conference › Paper › peer-review

Abstract

A disadvantage of the continuous recycling process of high density (HD) sludge in the treatment of Acid Mine Drainage (AMD) from Horobetsu is the formation of ultra fine solid particles (UFP) in a low concentration. These suspended particles complicate the rapid separation. This article analyses a batch-type recycling process for the HD-sludge. Experiments were conducted with various neutralizers at pH 7 and the separation of suspended ultra fine particles was done by means of ferro-nickel slag (FS) fibers in a glass column. Different phenomena were analysed: the iron-sludge density and composition, the influence of electrocinetic surface phenomena in the generated sludge and the separation of the suspended UFP in a FS-fiber-bed. The neutralizers increase the density of the iron sludge, yet irregularly with the progression of the recycling. A MgO-based neutralizer provided the densest sludge followed by a two-step neutralizer, while Ca(OH)₂ and NaOH provided the least dense sludge. The strong effect of MgO is due to the large negative minimum potential energy (Vt_min) from Fe(OH)₃ as basic ferric sulphate and undissolved MgO. Also the sludge from the two-step-method has large negative Vt_min from Fe(OH)₃ and undissolved CaCO₃. The difference to MgO can be explained by a smaller negative Vt_min caused by heterocoagulation with other sludge materials, and by the sludge composition and concentration. The Fe(OH)₃- and CaSO₄-sludge from the Ca(OH)₂-neutralization and the Fe(OH)₃-sludge as basic ferric sulphate from the NaOH-neutralization have smaller Vt_min, resulting in low iron density. FS-fibers are very effective media to separate suspended UFP. The separation process is controlled by the Vt_min from the heterecoagulation of the UFP and the FS followed by the homocoagulation of UFP. As a result, the utilization of FS-fibers in the column bed improved the continuous-type HD-sludge recycling process.

Original language	English
Pages	421-437
Number of pages	17
Publication status	Published - 2005
Event	European Metallurgical Conference, EMC 2005 - Dresden, Germany Duration: 2005 Sept 18 → 2005 Sept 21

Conference

Conference	European Metallurgical Conference, EMC 2005
Country/Territory	Germany
City	Dresden
Period	05/9/18 → 05/9/21

Keywords

Acid mine drainage
Coagulation
Filtration
High density sludge
Recycling
Solid-liquid separation
Waste effluent treatment

ASJC Scopus subject areas

Metals and Alloys

Cite this

@conference{0f9916b622a94601a76792b6c047da31,

title = "Chemical surface mechanisms in rapid solid-liquid separation of sludge from HD-sludge recycling of AMD (Horobetsu)",

abstract = "A disadvantage of the continuous recycling process of high density (HD) sludge in the treatment of Acid Mine Drainage (AMD) from Horobetsu is the formation of ultra fine solid particles (UFP) in a low concentration. These suspended particles complicate the rapid separation. This article analyses a batch-type recycling process for the HD-sludge. Experiments were conducted with various neutralizers at pH 7 and the separation of suspended ultra fine particles was done by means of ferro-nickel slag (FS) fibers in a glass column. Different phenomena were analysed: the iron-sludge density and composition, the influence of electrocinetic surface phenomena in the generated sludge and the separation of the suspended UFP in a FS-fiber-bed. The neutralizers increase the density of the iron sludge, yet irregularly with the progression of the recycling. A MgO-based neutralizer provided the densest sludge followed by a two-step neutralizer, while Ca(OH)2 and NaOH provided the least dense sludge. The strong effect of MgO is due to the large negative minimum potential energy (Vtmin) from Fe(OH)3 as basic ferric sulphate and undissolved MgO. Also the sludge from the two-step-method has large negative Vtmin from Fe(OH)3 and undissolved CaCO3. The difference to MgO can be explained by a smaller negative Vtmin caused by heterocoagulation with other sludge materials, and by the sludge composition and concentration. The Fe(OH)3- and CaSO4-sludge from the Ca(OH)2-neutralization and the Fe(OH)3-sludge as basic ferric sulphate from the NaOH-neutralization have smaller Vtmin, resulting in low iron density. FS-fibers are very effective media to separate suspended UFP. The separation process is controlled by the Vtmin from the heterecoagulation of the UFP and the FS followed by the homocoagulation of UFP. As a result, the utilization of FS-fibers in the column bed improved the continuous-type HD-sludge recycling process.",

keywords = "Acid mine drainage, Coagulation, Filtration, High density sludge, Recycling, Solid-liquid separation, Waste effluent treatment",

author = "Badulis, {G. C.} and C. Tokoro and H. Sasaki",

year = "2005",

language = "English",

pages = "421--437",

note = "European Metallurgical Conference, EMC 2005 ; Conference date: 18-09-2005 Through 21-09-2005",

}

TY - CONF

T1 - Chemical surface mechanisms in rapid solid-liquid separation of sludge from HD-sludge recycling of AMD (Horobetsu)

AU - Badulis, G. C.

AU - Tokoro, C.

AU - Sasaki, H.

PY - 2005

Y1 - 2005

N2 - A disadvantage of the continuous recycling process of high density (HD) sludge in the treatment of Acid Mine Drainage (AMD) from Horobetsu is the formation of ultra fine solid particles (UFP) in a low concentration. These suspended particles complicate the rapid separation. This article analyses a batch-type recycling process for the HD-sludge. Experiments were conducted with various neutralizers at pH 7 and the separation of suspended ultra fine particles was done by means of ferro-nickel slag (FS) fibers in a glass column. Different phenomena were analysed: the iron-sludge density and composition, the influence of electrocinetic surface phenomena in the generated sludge and the separation of the suspended UFP in a FS-fiber-bed. The neutralizers increase the density of the iron sludge, yet irregularly with the progression of the recycling. A MgO-based neutralizer provided the densest sludge followed by a two-step neutralizer, while Ca(OH)2 and NaOH provided the least dense sludge. The strong effect of MgO is due to the large negative minimum potential energy (Vtmin) from Fe(OH)3 as basic ferric sulphate and undissolved MgO. Also the sludge from the two-step-method has large negative Vtmin from Fe(OH)3 and undissolved CaCO3. The difference to MgO can be explained by a smaller negative Vtmin caused by heterocoagulation with other sludge materials, and by the sludge composition and concentration. The Fe(OH)3- and CaSO4-sludge from the Ca(OH)2-neutralization and the Fe(OH)3-sludge as basic ferric sulphate from the NaOH-neutralization have smaller Vtmin, resulting in low iron density. FS-fibers are very effective media to separate suspended UFP. The separation process is controlled by the Vtmin from the heterecoagulation of the UFP and the FS followed by the homocoagulation of UFP. As a result, the utilization of FS-fibers in the column bed improved the continuous-type HD-sludge recycling process.

AB - A disadvantage of the continuous recycling process of high density (HD) sludge in the treatment of Acid Mine Drainage (AMD) from Horobetsu is the formation of ultra fine solid particles (UFP) in a low concentration. These suspended particles complicate the rapid separation. This article analyses a batch-type recycling process for the HD-sludge. Experiments were conducted with various neutralizers at pH 7 and the separation of suspended ultra fine particles was done by means of ferro-nickel slag (FS) fibers in a glass column. Different phenomena were analysed: the iron-sludge density and composition, the influence of electrocinetic surface phenomena in the generated sludge and the separation of the suspended UFP in a FS-fiber-bed. The neutralizers increase the density of the iron sludge, yet irregularly with the progression of the recycling. A MgO-based neutralizer provided the densest sludge followed by a two-step neutralizer, while Ca(OH)2 and NaOH provided the least dense sludge. The strong effect of MgO is due to the large negative minimum potential energy (Vtmin) from Fe(OH)3 as basic ferric sulphate and undissolved MgO. Also the sludge from the two-step-method has large negative Vtmin from Fe(OH)3 and undissolved CaCO3. The difference to MgO can be explained by a smaller negative Vtmin caused by heterocoagulation with other sludge materials, and by the sludge composition and concentration. The Fe(OH)3- and CaSO4-sludge from the Ca(OH)2-neutralization and the Fe(OH)3-sludge as basic ferric sulphate from the NaOH-neutralization have smaller Vtmin, resulting in low iron density. FS-fibers are very effective media to separate suspended UFP. The separation process is controlled by the Vtmin from the heterecoagulation of the UFP and the FS followed by the homocoagulation of UFP. As a result, the utilization of FS-fibers in the column bed improved the continuous-type HD-sludge recycling process.

KW - Acid mine drainage

KW - Coagulation

KW - Filtration

KW - High density sludge

KW - Recycling

KW - Solid-liquid separation

KW - Waste effluent treatment

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M3 - Paper

AN - SCOPUS:84871336341

SP - 421

EP - 437

T2 - European Metallurgical Conference, EMC 2005

Y2 - 18 September 2005 through 21 September 2005

ER -

Chemical surface mechanisms in rapid solid-liquid separation of sludge from HD-sludge recycling of AMD (Horobetsu)

Abstract

Conference

Keywords

ASJC Scopus subject areas

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