Introduction of JOGMEC's latest R&D of mining pollution control...

Introduction of JOGMEC's latest R&D of mining pollution control techniques

Kazunori HATSUYA Planning Division

Metals Environment Management Department Japan Oil, Gas and Metals National Corporation

(JOGMEC)

7th February, 2014 JOGMEC Seminar on Exploration and Mine Pollution Control

Outline

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1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant)

Current Matsuo neutralization plant and surrounding

Operating Matsuo sulfur mine (1953)

The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974)

Current Matsukawa R.

share our experience and technology for sustainable development of African mining sector!

Aim…

Outline

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Aim…

4

Measures for mine pollution control

Plug sealing Protection channel Soil covering and grass planting Neutralization

FeS2 + 7/2O2 + H2O → Fe2+ + 2SO4

2- + 2H+

Pyrite

Sulfate ion

Generation mechanism of acid drainage

Measures against acid drainage generation / treatment

5

Current situation of drainage treatment in Japan

Suspended or abandoned mine with owner (55) Abandoned mine without owner (24)

Mines practicing drainage treatment

200km

Matsuo neutralization plant (Administrated by JOGMEC)

Flowchart of general acid drainage treatment

Sludge dam Thickener

Neutralization tank

Functions of JOGMEC in the field of mine pollution control

JOGMEC

Mine administrators Local government

The administrator of ownerless mine Mining company

Mining right owner

Mining countries

Government of Japan

1. Technical support Research and

consulting, Support of construction works, Administration of treatment plant, Education, Information providing

2. Research and development

Mine pollution control technologies

3. Financial support

Management of the mine pollution control reserve and fund

Loan for mine pollution control construction

4. International cooperation

Holding of technical seminar and hosting of trainees

Grant

6

JOGMEC’s R&D of mining pollution control technologies

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1970～・Technology for vegetation at dams ・Technology for closure of tunnel 1980～・Technology for returning sludge into underground caves ・Technology for agglomeration of sludge 1990～・Mine drainage treatment technology using sulfate reducing bacteria ・Centralized management technology for drainage from plural mines ・Mine drainage treatment technology using coal ash ・Technology for economical use of energy in mine drainage treatment 2000～・Treatment technology for B, F and Sb in mine drainage ・Sludge reduction technology (using iron oxidizing bacteria) ・Passive treatment (using sulfate reducing bacteria, phytoremediation)

Outline

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Aim…

バクテリア回収槽

処理原水（pH1.8前後）

放流

原水槽

殿物繰返し

（～pH6.5）

炭カル消石灰

（pH7.5）

殿物（スラリーを脱水）


酸化槽 (pH2.5前後）


放流原水槽

バクテリア着床泥の返泥Al主体殿物（資源化）

鉄酸化工程中和工程

固液分離槽

脱鉄槽（pH3.5）

Fe主体殿物（砒素の共沈）

中和槽（pH7）

炭カル消石灰

中和泥の返泥

Calcium Calcium

CarbonateCarbonateAMDAMD

(pH1.8)(pH1.8)Slaked limeSlaked lime

Sludge recyclingSludge recycling

～～pH6.5pH6.5 pH7.5pH7.5

Bacteria recovery Bacteria recovery

tanktank

Overflow releaseOverflow release

Dewatered sludgeDewatered sludge

AMDAMD

(pH1.8)(pH1.8)

AMD storage AMD storage

tanktank


tanktank

Ion Ion oxidazingoxidazing

tanktank

(pH2.5)(pH2.5)

Calcium Calcium

CarbonateCarbonate

pH controlpH control

tanktank

(pH3.5)(pH3.5)


tanktank

Slaked limeSlaked lime

Neutralizing tankNeutralizing tank

(pH7.0)(pH7.0)

Sludge with bacteriaSludge with bacteria

Sludge Sludge

(Fe, As)(Fe, As)

SolidSolid--liquid liquid

separation tankseparation tank

SludgeSludge

Sludge Sludge

(Al)(Al)

OverflowOverflow

releaserelease

Ion oxidation processIon oxidation process Neutralizing processNeutralizing process



放流

原水槽

殿物繰返し

（～pH6.5）

炭カル消石灰

（pH7.5）

殿物（スラリーを脱水）


酸化槽 (pH2.5前後）


放流原水槽

バクテリア着床泥の返泥Al主体殿物（資源化）

鉄酸化工程中和工程

固液分離槽

脱鉄槽（pH3.5）

Fe主体殿物（砒素の共沈）

中和槽（pH7）

炭カル消石灰

中和泥の返泥

Calcium Calcium

CarbonateCarbonateAMDAMD

(pH1.8)(pH1.8)Slaked limeSlaked lime

Sludge recyclingSludge recycling

～～pH6.5pH6.5 pH7.5pH7.5


tanktank

Overflow releaseOverflow release

Dewatered sludgeDewatered sludge

AMDAMD

(pH1.8)(pH1.8)


tanktank


tanktank

Ion Ion oxidazingoxidazing

tanktank

(pH2.5)(pH2.5)

Calcium Calcium

CarbonateCarbonate

pH controlpH control

tanktank

(pH3.5)(pH3.5)


tanktank

Slaked limeSlaked lime

Neutralizing tankNeutralizing tank

(pH7.0)(pH7.0)

Sludge with bacteriaSludge with bacteria

Sludge Sludge

(Fe, As)(Fe, As)

SolidSolid--liquid liquid

separation tankseparation tank

SludgeSludge

Sludge Sludge

(Al)(Al)

OverflowOverflow

releaserelease

Ion oxidation processIon oxidation process Neutralizing processNeutralizing process

Iron oxidizing bacteria (Fe2+ → Fe3+)

Over flow

To reduce the volume of sludge and the amount of neutralizer

Fe: more than 300m g/L, as Fe2+ SO4:more than 2000mg/L

pH:7.4, Fe: 0m g/L

Acid drainage treatment with iron oxidizing bacteria Current flow

Proposed flow (Bacterial oxidation and two step neutralization)

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Solid-liquid separation tank

On-site test Small scale test

The achievements of on-site test ・Amount of neutralizer: 19.8% down ・Volume of sludge: 37.6% down ・Running cost: 18.4～31.1% down

4,607

1,315

1,558

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

Conventional system (therecord of 2005 fisical year)

Proposed process (anestimate)

Cak

e vo

lum

e (m

3 /

yea

r)

Precipitation in Ca(OH)2neutralizing

Precipitation in bacteriaoxidizing

Test result of acid drainage treatment with iron oxidizing bacteria

Sakoda et al. (2014, in press)

Sludge cake

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Outline

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Aim…

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Active treatment versus Passive treatment ・Active treatment “Active treatment is the improvement of water quality by methods which require ongoing inputs of artificial energy and/or (bio)chemical reagents” ・Passive treatment “Passive treatment is the deliberate improvement of water quality using only naturally-available energy sources (e.g. gravity, microbial metabolic energy, photosynthesis), in systems which require only infrequent (albeit regular) maintenance in order to operate effectively over the entire system design life” “Mine Water: Hydrology, Pollution, Remediation” Paul L. Younger et al.

Merits of passive treatment ●Dramatically reduce the cost of water treatment ・Maintenance almost-free → Reduce labor cost ・Using natural purifying effect → Reduce running cost (chemicals, electricity etc.) → Harmony with natural landscape

Demerits of passive treatment ●Difficulties in securing the stability of purification capability ・Purification capability is affected by the

change of temperature and quality of drainage

・Severe water quality management is required under the principles of compliance of water effluent standard

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Some types of passive treatment

Require chemicals

Not require chemicals

Open Close aerobic anaerobic

Use limestone

Use bacteria

Anoxic limestone drain (pH neutralization)

Oxic limestone drain (pH neutralization,

Fe2+ oxidation)

Aerobic wetland (iron oxidization by bacteria)

Anaerobic wetland PRB (permeable reacting barrier)

(sulfate reduction by bacteria) ・Fe2+ → Fe3+ at low pH ・small amount of heavy metals are co-precipitate with Fe3+ oxide

・heavy metals are precipitate as sulfide

・sterilized at acid condition ・inactive at low temperature (below 15℃)

・require nutrition (organic carbon)

・inhibit precipitation of Fe3+ oxide (Fe3+ oxide covers the limestone and prevents pH neutralization)

・require Fe2+ oxidation in later process

・easy chemical reaction, easy installation ・Fe3+ oxide precipitate on the surface of limestone and prevents pH neutralization

Under R&D by JOGMEC

Removal of suspended

solids (gravity settling)

Limestone drain

Settlement tank

Aerobic wetland

Anaerobic wetland

Abandoned mine

Drainage

pH neutralization

(limestone)

Natural river

Treated water

Oxidation and precipitation of

Fe2+

(iron oxidizing bacteria)

Precipitation and filtration of Zn, Cu

etc.

(sulfate reducing bacteria)

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Model of passive treatment by wetland

Artificial aerobic wetland in northern Japan (Hokkaido Research Organization)

Artificial anaerobic wetland in northern Japan (Hokkaido Research Organization)

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Mechanism of anaerobic bioreactor

(MOFF)

Brown rice

Rice husk

・Procurable on site ・Cost almost nothing

Laboratory test ・In JOGMEC’s Metals Technology Center

・From 2008 ・Litter-scale column

On site test ・Near abandoned mine ・From 2009, for neutral pH drainage ・From 2013, for acid drainage ・Litter～Cubic meter-scale column

Demonstration test

Current tests of anaerobic bioreactor treatment

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9

Influent Water Quality (C mine):

pH : 3.3~3.8 Zn : 12.5 ~ 19.0 mg/L Cu : 6.0 ~ 12.0 mg/L Pb : 0.7 ~ 1.5 mg/L Cd : 0.15~0.25 mg/L SO42-: 200 mg/L

3.0

4.0

5.0

6.0

7.0

8.0

9.0

0 50 100 150 200 250 300

pH

0

50

100

150

200

250

0 50 100 150 200 250 300

SO

42

-co

nc.

(m

g/L

)

0

5

10

15

20

25

0 100 200 300

S2

-co

nc.

(m

g/L

)

0.0

5.0

10.0

15.0

20.0

0 50 100 150 200 250 300

Zn

co

nc.

(m

g/L

)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 50 100 150 200 250 300

Cd

co

nc.

(m

g/L

)

0

5

10

15

0 50 100 150 200 250 300

Cu

co

nc.

(m

g/L

)

3.0

4.0

5.0

6.0

7.0

8.0

9.0

0 50 100 150 200 250 300

pH

0

50

100

150

200

250

0 50 100 150 200 250 300

SO

42

-co

nc.

(m

g/L

)

0

5

10

15

20

25

0 100 200 300

S2

-co

nc.

(m

g/L

)

0.0

5.0

10.0

15.0

20.0

0 50 100 150 200 250 300

Zn

co

nc.

(m

g/L

)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 50 100 150 200 250 300

Cd

co

nc.

(m

g/L

)

0

5

10

15

0 50 100 150 200 250 300

Cu

co

nc.

(m

g/L

)

0.00

0.50

1.00

1.50

2.00

0 50 100 150 200 250 300

Pb

co

nc.

(m

g/L

)

3.0

4.0

5.0

6.0

7.0

8.0

9.0

0 50 100 150 200 250 300

pH

0

50

100

150

200

250

0 50 100 150 200 250 300

SO4

2-co

nc.

(m

g/L

)

0

5

10

15

20

25

0 100 200 300

S2-co

nc.

(m

g/L

)

0.0

5.0

10.0

15.0

20.0

0 50 100 150 200 250 300

Zn c

on

c. (

mg

/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 50 100 150 200 250 300

Cd

co

nc.

(m

g/L

)0

5

10

15

0 50 100 150 200 250 300

Cu

co

nc.

(m

g/L

)

3.0

4.0

5.0

6.0

7.0

8.0

9.0

0 50 100 150 200 250 300

pH

0

50

100

150

200

250

0 50 100 150 200 250 300

SO

42

-co

nc.

(m

g/L

)

0

5

10

15

20

25

0 100 200 300

S2

-co

nc.

(m

g/L

)

0.0

5.0

10.0

15.0

20.0

0 50 100 150 200 250 300

Zn

co

nc.

(m

g/L

)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 50 100 150 200 250 300

Cd

co

nc.

(m

g/L

)

0

5

10

15

0 50 100 150 200 250 300

Cu

co

nc.

(m

g/L

)

Influent water

Treated water

National effluent standard

Laboratory test of anaerobic bioreactor treatment

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Curried out Litter-scale column test for drainages from 7 different mines Heavy metals are continuously removed from drainages (test period: 1～2 years)

days days days

0 10 20 30 40 50 60

⑦ 30-35cm

⑤ 20-25cm

③ 10-15cm

② 5~10cm

① 0-5cm

金属量(mg）

Zn

Cd

Cu

Upper part

SEM Sulfur

Zinc Copper

Lower part

Laboratory test of anaerobic bioreactor treatment

Acid soluble metals in column ingredient (mg)

18 Small sulfide metals (μm-size) were observed in column ingredient

Freeze and cut Ingredient of column

Heavy metals are promptly precipitated at injection side 18

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Treatment Tank１～３（300L）

Storage Tank（1000L）

（1000L）（1000L）（1000L）

Return to Existing Active Treatment Facility

Mine water storage tank (300L)

Reactor１pH:5.91Cd:0.103mg/LSO4

2-:250mg/L

Reactor2 Reactor3

Flow rate: 200mL/min each

IndoorActive Treatment Plant

Temporary Storage Tank

Magnetic ValveOld tailing dam

～原水中継槽～～試験建屋正面～～試験建屋内部～手前タンク：原水槽

後方タンク：反応槽1～3

～建屋裏～処理槽1～3

（右上：充填されている活性炭）

～建屋側面～貯水槽

Reactor

On site test of anaerobic bioreactor treatment for neutral pH drainage

Section of reactor

Influent Water Quality:

pH : 6.0~7.8 Zn : 0.8 ~ 2.0 mg/L Cd : 0.03~0.15 mg/L SO42-: 150~280mg/L

Reactor 1 Reactor 2 Reactor 3

Organic ingredient Rice husk Rice husk Rice husk & Composted bark

with cow manure

Residence time 12.5 ～ 50 hours 50 hours 50 hours → 25 hours

Test site

On site test of anaerobic bioreactor treatment for neutral pH drainage

Reactor 1 Reactor 2 Reactor 3

Organic ingredient Rice husk Rice husk Rice husk & Composted bark

with cow manure

Residence time 12.5 ～ 50 hours 50 hours 50 hours → 25 hours

HRT: 50 → 25 HRT: 50 → 25 (HRT: Hours of residential time)

Rice husk Composted bark with cow

manure

Heavy metals are continuously removed in all reactors (test is ongoing)

Zn and Cd concentration of influent and effluent of reactor 3 during >1000 days

20

Influent Water Quality:

pH : 3.3~3.5 Zn : 15 ~ 20 mg/L Cd : 0.05 mg/L Pb : 0.08 mg/L Cu : 5 ~ 10 mg/L SO42-: 350 ~ 400 mg/L

On site test of anaerobic bioreactor treatment for acid drainage

HRT: Hours of residential time

Receiving tank and reactors

Test site (northern Japan)

・Colum size: 35L ・Main ingredient: Rice husk, limestone, mud

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Heavy metals are continuously removed in reactors despite low temperature (test is ongoing)

Outline

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Aim…

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Mechanism of phytoremediation by hyperaccumulator

Arabis gemmifera (for Zn, Cd) Funaria hygrometrica (for Pb, Au)

Phytoremediation is the direct use of green plants and their associated microorganisms to stabilize or reduce contamination in soils, sludges, sediments, surface water, or ground water. (US PEA)

From 2013, JOGMEC conducts joint study of phytoremediation with national institutes / universities.

Eleocharis acicularis (for heavy metals) Mechanism of phytoremediation (Sakakibara, 2013)

Decomposition / Transformation / Accumulation

Evaporation / Diffusion

Move to aerial part Removal

Stabilization

Discharge

Stimulate microorganism Absorption

Examples of hyperaccumulator

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“Floating cultivation method” → Adsorb heavy metals directory from water

JOGMEC and Ehime Univ. jointly conduct on site test at other abandoned mines.

Ehime University launched on site test of phytoremediation for mine drainage by using E. acicularis.

Example of on site test of phytoremediation

(Sakakibara, per comm)

Example of on site test of phytoremediation

(Sakakibara, per comm)

Change of heavy metal concentration of E. acicularis soaked in acid drainage during 27 days (in October 2013)

E. Acicularis promptly accumulates heavy metals

Drainage:

pH : 3.3~5.6 Fe : 4.6 ~ 2.5 mg/L Cu : 0.1 mg/L Pb : 0.033 ~ 0.006 mg/L Zn : 6.7 ~ 2.5 mg/L As : 0.002 ~ 0.001 mg/L Cd : 0.03 ~ 0.01 mg/L Al : 11 ~ 2 mg/L

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Thank you for your attention!

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Introduction of JOGMEC's latest R&D of mining pollution control...

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