11

Mercury Use Reduction and Land Mercury Use Reduction and Land Reclamation in the Tapajos Region, BrazilReclamation in the Tapajos Region, Brazil

by Rodolfo N. Sousa/ Marcello Veiga by Rodolfo N. Sousa/ Marcello Veiga

CASM Conference - Brasilia Oct/2008

Global Mercury ProjectGlobal Mercury Project

A United Nations (GEF/UNIDO) A United Nations (GEF/UNIDO) program created in 2002 aiming to:program created in 2002 aiming to:

Reduce Hg pollution caused by ASMReduce Hg pollution caused by ASM

Introduce and disseminate good Introduce and disseminate good practicespractices

Train miners and develop community Train miners and develop community awareness awareness

22

TanzaniaTanzania

SudanSudan

ZimbabweZimbabwe

BrazilBrazil

IndonesiaIndonesiaLaosLaos

In collaboration with UBC Dept of Mining Engineering

Ecuador

Venezuela

Guinea

Ghana

Mozambique

CambodiaSuriname

Senegal

Colombia

Global Mercury ProjectGlobal Mercury Project

44

The Amazon scenario

Area of 5,5 million kmArea of 5,5 million km22 in 9 countries, of which in 9 countries, of which 72% (4 million km72% (4 million km22) is located in Brazil) is located in Brazil

The Brazilian Amazon has lost 18% of its original The Brazilian Amazon has lost 18% of its original area or 650,000 kmarea or 650,000 km22 (larger than France) (larger than France)

The Amazon looses 0.27% - 0.65% of its area The Amazon looses 0.27% - 0.65% of its area every year or 24,000 kmevery year or 24,000 km22 (the size of Belgium) (the size of Belgium)

Deforestation in the Amazon started in 1970’sDeforestation in the Amazon started in 1970’s

55

Deforestation in the AmazonDeforestation in the Amazon

4 million km2

Garimpo Canaan

Brasilia

18% deforestation

1980’s: Serra Pelada, the largest 1980’s: Serra Pelada, the largest concentration of miners in the worldconcentration of miners in the world

66

2008: Typical Mining communities 2008: Typical Mining communities (“garimpos”)(“garimpos”)

77

Magnitude of ASM in the TapajósMagnitude of ASM in the Tapajós

40,000 miners40,000 miners

500 to 2,000 mining sites500 to 2,000 mining sites

400 air strips400 air strips

5.8 tonnes/year of gold 5.8 tonnes/year of gold

10-12 tonnes/year of Hg for amalgamation10-12 tonnes/year of Hg for amalgamation

88

Socio-economic aspectsSocio-economic aspects

Most miners do not have mining permit or Most miners do not have mining permit or environmental license;environmental license;

Education is very limited;Education is very limited;

Gold is the main source of revenue;Gold is the main source of revenue;

A miner consumes 40g Hg/month, produces A miner consumes 40g Hg/month, produces 18g Au/month, and income of US$350/month18g Au/month, and income of US$350/month

Hg costs US$200/kg. Au is sold by US$25/g.Hg costs US$200/kg. Au is sold by US$25/g.

99

Environmental and Health AspectsEnvironmental and Health Aspects

Mercury contamination: Mercury contamination: soil, air, biota, fish, soil, air, biota, fish, miners;miners;

High level of Hg in fish: High level of Hg in fish: 4 to 5ppm, cases of 4 to 5ppm, cases of 22ppm, whereas guideline is 0.5ppm;22ppm, whereas guideline is 0.5ppm;

Mercury vapor: Mercury vapor: amalgamation without retorts amalgamation without retorts and gold shops without proper filters;and gold shops without proper filters;

Water contamination: Water contamination: tailings disposed tailings disposed directly into the rivers (siltation exacerbates directly into the rivers (siltation exacerbates bioaccumulation), Hg, CN, oil, sewage, bioaccumulation), Hg, CN, oil, sewage, garbagegarbage

1010

Environmental and Health AspectsEnvironmental and Health Aspects

Drinking water: Drinking water: water consumed directly water consumed directly from local streams, no latrines or proper from local streams, no latrines or proper waste disposal, high level of malaria and waste disposal, high level of malaria and parasitosisparasitosis

Deforestation:Deforestation: pits are open in critical areas pits are open in critical areas along the streams and rivers. Very low level along the streams and rivers. Very low level of land reclamationof land reclamation

1111

Hydraulic monitors – huge open pits in the forestHydraulic monitors – huge open pits in the forest

1212

Sediment / tailings released directly into the riversSediment / tailings released directly into the rivers

1313

Sediments / tailings released directly into the riversSediments / tailings released directly into the rivers

1414

Sediment released by sluice boxes – Crepori RiverSediment released by sluice boxes – Crepori River

1515

Mobility of Hg-contaminated Tailings

1616

Tailings take >4 t/a of Hg to other areas

Hg is methylated and bioaccumalted downstream

Crepori River

200km

Tapajós River

Hg-rich Tailings from gold miners

Source: Telmer et al. (2006)

1717

ASM in the TapajosASM in the Tapajos

In 2006, Brazil produced 40 tonnes of gold, of In 2006, Brazil produced 40 tonnes of gold, of which 5.2 tonnes were produced by ASM which 5.2 tonnes were produced by ASM (estimated 3 tonnes in the Tapajos)(estimated 3 tonnes in the Tapajos)

300 – 600 pits, each with a volume greater than 300 – 600 pits, each with a volume greater than 10,000m10,000m33 are opened annually are opened annually

3 to 6,000,000 tonnes/a of tailings into the rivers 3 to 6,000,000 tonnes/a of tailings into the rivers

Area disturbed by excavation of pits by hydraulic Area disturbed by excavation of pits by hydraulic monitors in the Tapajos is around 12,000 hamonitors in the Tapajos is around 12,000 ha

Scenario of Artisanal Mining an GMP’s approachScenario of Artisanal Mining an GMP’s approach

1818

Large number of people involvedLarge number of people involved Low level of formal education and basic infra structureLow level of formal education and basic infra structure Most miners are informal / ASM is a marginal activityMost miners are informal / ASM is a marginal activity ASM causes more environmental impact than most large ASM causes more environmental impact than most large

companies but they are not in the mediacompanies but they are not in the media Very low investment for ASM on the groundVery low investment for ASM on the ground

UNIDO / GMP acknowledge that:UNIDO / GMP acknowledge that: The project is a very important initiative, but very small in The project is a very important initiative, but very small in

scale when compared with the scale of the problem. scale when compared with the scale of the problem. Education and prevention are keywords for the success of Education and prevention are keywords for the success of

the projectthe project

1919

1. Training is a step to reach a result, but it is not a result in itself;

2. Number of trainees and program content are important information, but are not the result itself;

3. Training people does not imply that they have learned lessons;

4. Learning lessons does not imply that they will implement what they have learned;

But,

The real result of training occurs when the trainees incorporate the lessons learned to their daily routine

General statements about General statements about training programstraining programs

2020

Objectives & effectiveness evaluationObjectives & effectiveness evaluation

5 MAIN OBJECTIVES: 5 MAIN OBJECTIVES: Promote legalization of minesPromote legalization of mines Improvement of Gold ProductionImprovement of Gold ProductionProtection of Forest and WaterProtection of Forest and WaterReduction of Hg UseReduction of Hg Use Improve Health and SanitationImprove Health and Sanitation

Evaluation of “garimpos” Evaluation of “garimpos” prior to the prior to the training and 3 to 4 months after training and 3 to 4 months after trainingtraining

2121

Project promotion: “Take care of your treasure”Project promotion: “Take care of your treasure”

2222

2323

Training of trainers (multipliers)

2424

Indoor TrainingIndoor Training

2525

Outdoor Training - Practical field lecturesOutdoor Training - Practical field lectures

2626

Multiplication of training / awareness campaignMultiplication of training / awareness campaign

2727

Multiplication of training / awareness campaignMultiplication of training / awareness campaign

2828

Evaluation before and after the trainingEvaluation before and after the training

2929

Introduction of biosand water filters

3030

Use of biosand filters for drinking water

3131

Accidents: landslides, fallings, motor pulley beltsAccidents: landslides, fallings, motor pulley belts

3232

Miner Burning Amalgam (exposed to Hg vapor)Miner Burning Amalgam (exposed to Hg vapor)

3333

Demonstration of homemade retorts

3434

Distribution of retorts to disseminate the culture of Distribution of retorts to disseminate the culture of protection against mercury vapour during the protection against mercury vapour during the

amalgam burningamalgam burning

3535

Kitchen bowl retort Kitchen bowl retort (homemade solution)(homemade solution) Hg condenses on

the glass bowl

Wet sand to seal Hg vapour

3636Brasil, 2006Brasil, 2006

3737

60 retorts like this purchased locally60 retorts like this purchased locally

Use of retorts to burn amalgam and recover HgUse of retorts to burn amalgam and recover Hg

3838

3939

Demonstration of mercury reactivation and recyclingDemonstration of mercury reactivation and recycling

4040

Fume hoods: developed local supplier, Filters installed Fume hoods: developed local supplier, Filters installed in local gold shopsin local gold shops

Fume hood in Gold Shops: GMP & USEPAFume hood in Gold Shops: GMP & USEPA

4141

TDU - Transportable Demonstration UnitTDU - Transportable Demonstration Unit

4242

Cyanidation tests – A lab in the jungleCyanidation tests – A lab in the jungle

4343

4444

Homemade prototypes (Homemade prototypes (amalgamator)amalgamator)

4545

Pool for amalgamation of concentratePool for amalgamation of concentrate

4646

Construction of latrinesConstruction of latrines

4747

Garbage disposalGarbage disposal

General structure of the Action PlanGeneral structure of the Action Plan

  

  

4848

Vision

Mission

General Objectives

Performance Indicators

Monitoring processes and results

Goals

Most relevant indicators

4949

General Objectives

Performance Indicator

% mines attaining requisites

Evaluation before

training

Goals for after

training

Results after

training

Protection of water and forest

Refilling old pits with tailings 40.6 80.0 91.7

Reforestation of degraded areas 1.5 5.0 5.0

Quality of water / sediment containment 35.1 60.0 91.7Use of Mercury

Mercury reactivation and recycling 4.3 50.0 91.7

Mercury confinement ( amalgamation) 10.9 50.0 75.0

Use of retorts during burning process 20.3 40.0 41.2Health, Sanitation

and SafetyUse of latrines 26.8 50.0 91.7

Use of filtered drinking water 17.0 60.0 81.3

Use of methods for prevention of malaria 62.0 80.0 81.3

Garbage disposal 16.3 50.0 100.0

Practices of internal awareness of miners 0.7 10.0 10.2

  Mean 21.4 48.6 69.2

5050

Reclamation in ASMReclamation in ASM

Complex and costly reclamation methods are not Complex and costly reclamation methods are not effective in ASM. effective in ASM.

Simplicity is mandatory. For example, soil Simplicity is mandatory. For example, soil salvation is an ideal technique but complex for salvation is an ideal technique but complex for ASMASM

Cases of rehabilitation are “volunteer initiatives”, Cases of rehabilitation are “volunteer initiatives”, as non-compliance is prevalentas non-compliance is prevalent

5151

Garimpo CanaanGarimpo Canaan

Garimpo Canaan is a typical ASM site in the Garimpo Canaan is a typical ASM site in the Tapajos with 10,000haTapajos with 10,000ha

Gold grade = 0.25 g/tGold grade = 0.25 g/t

The area is only accessible by boat or small The area is only accessible by boat or small airplanesairplanes

Process: hydraulic monitors, sluice boxes and Process: hydraulic monitors, sluice boxes and mercury amalgamationmercury amalgamation

Canaan employs around 20 people, involving Canaan employs around 20 people, involving miners, cook, general helpersminers, cook, general helpers

5252

Garimpo CanaanGarimpo Canaan

Reclamation StepsReclamation Steps

1.1. Relocation of sluice boxes to fill old open pitsRelocation of sluice boxes to fill old open pits

2.2. Triple barrier to retain sediments Triple barrier to retain sediments

3.3. Seedling productionSeedling production

4.4. Fertilization / silvicultural managementFertilization / silvicultural management

5.5. Harvest managementHarvest management

5353

Garimpo CanaanGarimpo Canaan

Objectives of the Objectives of the reclamation program: reclamation program:

Reduction of river siltation; Reduction of river siltation; Recomposing the landscape; Recomposing the landscape; Diversification of the economyDiversification of the economy

Amazonian Mahogany (Amazonian Mahogany (Swietenia macrophylla Swietenia macrophylla KingKing) reaches price of US$ 800/) reaches price of US$ 800/mm33

One hectare of One hectare of Mahogany Mahogany with 556 trees can with 556 trees can produce 100 mproduce 100 m3 3 in 25 years in 25 years

5454

Environmental Impact of planting Environmental Impact of planting MohoganyMohogany

Natural density of Mahogany in the Amazon Natural density of Mahogany in the Amazon forest ranges from 0.3 to 2.1 trees/ha forest ranges from 0.3 to 2.1 trees/ha

The plantation in Canaan produced 285 to 555 The plantation in Canaan produced 285 to 555 trees/ha, which is equivalent to the amount of trees/ha, which is equivalent to the amount of Mahogany found in 1,000 ha of natural forest Mahogany found in 1,000 ha of natural forest

For each Mahogany tree harvested in the natural For each Mahogany tree harvested in the natural environment, about 31 other trees with diameter environment, about 31 other trees with diameter above 10 cm are cut in order to obtain the above 10 cm are cut in order to obtain the MahoganyMahogany

Sluice box removed from river / barrier to retain sedimentsSluice box removed from river / barrier to retain sediments

5555

Open Pit: 20,000 m3 earth to rivers Sluice box removed from river.

Triple barrier to retain sediments Old pit refilled. Clean water to river

Refilling old pits: most critical step in rehabilitationRefilling old pits: most critical step in rehabilitation

5656

5757

Reforested areas in CanaanReforested areas in CanaanArea denomination

1A 1B 1C 1D

Common name African Mahogany Neem Teak Amazon

Mahogany

Scientific name Khaya ivorensis

Azadirachta indica

Tectona grandis

S. macrophylla King

Area (m2) 16310 54215 17885 7578

# seedlings 466 1549 511 421

Date plantation Feb/03 Feb/03 Mar/04 Apr/02

Age (years) 5.8 5.8 4.7 6.6

Spacing (m) 7 x 5 7 x 5 7 x 5 6 x 3

# trees/ha 285 285 285 556

5858

Reforested areas in CanaanReforested areas in Canaan

Block Species Diameter Height Basal area Volume Survival

Rate  

 Common

name (cm) (m) B/ha m3/ha (%)

1A African Mahogany 15.16 9.59 4.61 23.19 81.05

1B Neem 14.43 7.40 6.73 25.61 90.00

1C Teak 10.94 7.68 2.79 11.29 97.91

1D Amazon. Mahogany 13.72 8.05 7.57 31.66 84.91

5959

Summary / lessons / Conclusions

141 locations, 4200 miners trained, 91.7% sluices removed from river after training (2nd evaluation)

300-600 open pits / year

6,000,000 tonnes of tailings

Garimpo Canaan was promoted as role model site

Refilling pits is the most important step in reclamation

If at least refilling is done, nature will provide coverage

Reforestation: Volume 100m3/ 25 years, >80 survival

Summary / lessons / Conclusions

SIMPLICITY is a key factor for the success of program in ASM (scale of ASM, remoteness, lack of infra structure and low level of formal education)

PREVENTION of environmental & health impact is cheaper, more rational and feasible than any corrective method

EDUCATION and AWARENESS are key factors for prevention and requires continuous training and campaigns.

EFFECTIVENESS must be evaluated and PERFORMANCE INDICATORS are appropriate tools

6060

Summary / lessons / Conclusions

20 “good practices” were promoted and 8 showed substantial impact: reactivation and recycling of mercury, pool for amalgamation, old pits refilling, sediment containment, garbage disposal, use of retorts, use of latrines, filtered water.

Practices related to promotion of legalization and gold production require more time for consolidation.

Local suppliers were prepared to develop retorts, fume hoods, filters and ball mill

6161

Summary / lessons / Conclusions

Impact on Hg reduction was 1,752kg (4,200 miners trained, Hg reactivation: 4.3% to 91.7%)

Potential to remove 16,780kg of Hg by extending the training for the whole population (40,000)

Improvement of grades (21.4 to 69.2%) is the best evidence that miners respond to education better than stringent legislation only.

Improvement of grades expresses changes in behaviour Mission Accomplished

6262