Download - Boojum Research LTD - 25 years of Ecological Engineering

Boojum Research LTD - 25 years of Ecological Engineering

Invited by West Virginia Mine Drainage Task Force Symposium

Morgantown , March 2011

M. Kalin and W. N. Wheeler Boojum Research Ltd

Toronto, Canada

The role of Phosphate and Phosphate mining wastes in

controlling ARD and AMD.

Is it a chemical or biological role or is it both ?


Margarete Kalin/Boojum Research LTD• President and founder of Boojum Research LTD

• Adjunct professor at U of Toronto, Ryerson University, U of Windsor, Queen’s Univeristy , Kingston

• QEP with the Institute of Environmental Practice and Senior Ecologist with the American Ecological Society.

• has written and presented more than 100 scientific papers, many book chapters and more than 100 technical reports

• has applied the technology to effluent streams from coal, uranium, base metal and precious metals in North and South America as well as Europe.

RECIPIENT OF THE: Noranda Award for Outstanding Achievement in the Field of Land Reclamation Teck-Cominco Environmental Award Distinguished Lecturer for the Canadian Institute of Mining.

No patents – Natural processes : Virtual Library

http://biblio.laurentian.ca/boojum

Company is 29 years old, with contracts worldwide.

Canadian contracts only shown


ECOLOGICAL ENGINEERING aims to practically and beneficially apply knowledge of how ecological systems operate on the mineral and rocks surfaces within these landforms

1838Ehrenberg

Gallionella ferruginea with ochreous deposits of bog

iron.

1887Winogradsky Beggiatoa

oxidation H2S to elemental sulfur; Leptothrix ochracea oxidation of FeCO3 to ferric

oxid

1919Harder

microbial iron oxidation and precipitation in iron

sedimentary deposits.

Stutzer (1911)Vernadsky (1908-1922)

Geomicrobiology has a long history- and they dominate the MWWMA ecosystem

These ecosystems are living landforms – they change with time

Mineral Surfaces: The Site of the Problem and the Solution

Oxidation of sulphide particles in tailings, waste-rock piles, underground mine workings and open pit walls Limited by the transport of oxygen

Convection, advection or diffusion to the mineral surface

Bacterial biofilm activity – BOTH OXIDATIVE AND REDUCTIVE – CHANGE THE HABITAT / ENVIRONMENT

Scale diagram of typical bacteria size compared to the surface roughness

Nutrients need to be added, NOT to the water, BUT to the rock surfaces and it has to stick to the rock in the oxidation pit

Members of this Task force did leading work with tests of phosphate material

Results from 5 Soxhlet leaching cycles – Appendix 1

My conclusion; Internal precipitation took place* Calculated average N=3 ** N= 24, each amendment all application rates N=3

pH Fe S Acidity Cond

NO PHOSPHATE* Cycle 1 2.0 1100 3000 360 14.20

Cycle 2 2.6 170 400 38 2.70

Cycle 3 2.8 55 140 29 1.66

Amendments all types including North Carolina phosphate

----------------------------- min – max -------------------------------

pH Fe S Acidity Cond

Cycle 1** 1.8 – 2.3 436 – 1206 3314 -1925 150 – 390 7.2 – 13.75

Cycle 2 2.8 – 3.6 25 – 119 190 – 493 8 – 32 1.3 – 2.36

Cycle 3 2.8 – 3.5 8 – 63 103 - 357 7 - 28 1.0 – 1.4

Field experiment

Control 1.14 t PO₄ 0.55 t PO₄45 28 25-55 -25 12550 5 -754.2 5.5 7.75

Day 500Mg FeS₂ OX per day/ per g FeS₂ NET ALKALINITY (mg/l CaCO₃)

ACID LOAD g/d CaCO₃ EQU.pH

• Fill #2 - 366 Tons shale/coal (parting)• Fill #6 - 367 Tons shale/coal l with 1.14 tons of apatite

rock• Fill #7 - 368 Tons shale/coal with .55 tons of apatite rock

Results were good – but did not make sense – so let‘s think what went wrong!

Acid Mine drainage treatment: Phosphate Technology- the chemical Phosphate role • P and Fe cycling are closely linked• P concentrations (e.g. for organisms) are generally very low• P is sequestered as co-precipitates with Fe hydroxides (oxic

conditions)• P forms metal salts (anoxic conditions)• P is bound by organics (e.g. humic substances in muskeg)• P may absorb to pyrite (source of AMD) surfaces and inhibit

acid generation

The Northern Miner Magazine Sept Oct.

1991 reported on the cessation leaching of

Cu from a dump in B.C.

Sample obtained in 1992


How did it start? A customer requested that something should be done to reduce oxidation rather than waiting for it occur!

The key questions are :

How do we get NPR to the mineral surface or to the place where the AMD is generated? AND It has to be economic and practicalIt has to be suistainable – lasting for everIt has to be general – i.e. work in all types of wastes

NPR Code 484 mm to < 0.04 mm

Relating the Scale of the Observations

Phosphate Rock

Waste Rock1

50mm

B- zone waste rock pile in distance with muskeg area in front


B-zone waste rock pile


B-zone waste rock pile

LOAD IN SEEPAGES As Fe SAnnual Load % Leached from pile %/year 0.26 0.0003 0.65Years to exhaustion year 378 322 153

Maximum elemental concentrations in Rock and Secondary Precipitate As Fe SWhole Rock

mg.g-1 2.7 43 1.5n=97

WRP-P Precipitatemg.g-1 242 206 7.2

n=1

Distribution of measured elements comprising 10% of a Waste Rock Pile As (0.07%)

S (0.29%)

Fe (10%)

We had to work in the field first – it has to work there, so we set up large field tests with Texas Gulf Natural Phosphate Rock – Train cars full of the stuff came to Northern Ontario and Quebec • In uranium tailings

• In phyrrotite tailings ( Cu , Ni ) • In coal, coarse waste rock • in polymetallic concentate spills• In sulphidic waste rock ( Cu , Zn )

Autopsy section overview

Piles 1 to 4Lime compacted etc

Pile 5 NPR

Tailings Surface Cover Development through Integration of Reactive Phosphate and Organic Matter (PHITO)


integrate nutrients, precipitation agents and NPR below the roots, then grow organics

Stanrock: Horse Manure and Natural Phosphate Rock 1995


Heterotroph Oxygen RequirementsHeterotrophs counted fresh tailings: 107/g

Populations oxygen requirement: 175µL/g

Oxygen present in fresh tailings: < 20 µL/g


Only practical long term tests in mining wastes in the field can provide evidence of the validity of the assumptions

•Tests NPR additions to tailings and conc. spill

•2- 85 % sulphide

• left in field 3.2-3.7 years

•monitor the pore water metal acidity

•TAILINGS AREA – Inco: 2700m2; Stanrock:432 m2

•Test NPR additions to waste rock •4-15 % sulphide •left outdoors 2.7 years •monitor the effluent metal acidity•Monitoring 1.8


Results of the waste rock drums

pH profile for low pyrite

Stable layer


Unstable layer

no matter what amount of pyrite – acid rock drainage is with you !

Uranium Pyhrrotite Polymetalic Waste rock

Elements (mg.L-1)

Control NPR Control NPR Control NPR Control NPR

N=1 N=1 N=1 N=1 N=2 N=2 N=3 N=6

Fe 18 0.01 43 0.1 1053 0.02 3.77 0.32

P 0.03 0.05 0.22 6.9 0.16 0.04 0.20 0.13

S 630 510 4460 1060 3020 500 126 123

pH 2.67 6.75 3.06 3.84 2.59 5.40 4.06 6.09

Acidity (mgCaCO3 .L-1) 656 39 6715 1090 5544 87 257 76

If sulphide oxidation can be reduced - the process has to be similar in a large variety of mining wastes:

Pore water results : Control NO NPR and NPR additions

OXIDATION RATES


r = 10-19.71 (±0.86). Eh12.93(±1.04). pH1.0(±0.29) (1)log r =-19.71(±0.86) + 12.93(±1.04)log(Eh) +1.0(±0.29)log(pH)

Williamson and Rumstidt . 1994

16x

The reactant: Phosphate mining wastes or Natural Phosphate Rock

• Un-economic for fertilizer production• a sedimentary deposit N. Carolina – Sea

shells –Shark teeth (organophosphate)

• grain size 4cm to < 0.04 mm• NPR contains 8-12 % P and 20-35 % Ca

(as CaCO3)

Taylor mesh conversion and size description for the NPR Code 48 particles

Taylor Mesh Size Used

Range of Particle Diameter (mm)

M.I.T Particle Classification

Percent finer than

Percentage of the total material

6 >3.35 Fine Gravel (44.8%)

90.754% 9.246%

8 2.36 - 3.35 55.183% 35.571%

10 1.7 - 2.36

Coarse Sand (52.0%)

10.281% 44.902%

14 1.18 - 1.7 4.826% 5.455%

20 0.85 - 1.18 3.881% 0.944%

28 0.6 - 0.85 3.229% 0.652%

35 0.425 - 0.6Medium Sand

(2.2%)

2.600% 0.630%

48 0.3 - 0.425 1.819% 0.781%

54 0.212 -0.3 1.008% 0.811%

100 0.15 - 0.212Fine Sand

(0.7%)

0.736% 0.271%

150 0.106 - 0.15 0.400% 0.336%

200 0.075 - 0.106 0.270% 0.130%

270 0.053 - 0.075

Silt (0.3%)

0.176% 0.094%

325 0.045 - 0.053 0.116% 0.060%

400 0.038 - 0.045 0.065% 0.051%

<400 <0.038 0.000% 0.065%

MACRONUTRIENTSMACRONUTRIENTSP (nucleic acids synthesis, ATP),

K (enzymes activation), Ca (cells walls and endospores),

Source :Chapelle, F; (1993 “Ground-Water Microbiology & Geochemistry” John Wiley & Sons, Inc)

1. NPR is acid-soluble and provides all the nutrients needed for microbial growth

2. It needs to be in particulate form on the mineral surface to change the environment

3. We suspect the fine particles made it to the mineral surface4. We dissolved NPR in 0.1N sulphuric acid and only a fraction of it dissolved

5. WE HAD THE BIOLOGICAL ROLE OF NPR!

-

MICRONUTRIENTSMICRONUTRIENTS Fe (electron transport systems),

Mn, Cu, Ni, Mo, Co and Zn (components of protein complexes and

enzyme activators)

Scanning Electron Microscopy of Waste Rock Surface (1st Observation)


1995


Boojum Research and U of Toronto(ongoing research)

After 3 years of outdoor exposure and 11 years of storage

P

SAu

Fe

20092007

AMIRA P933 Report

Mineral Surfaces: The Site of the Problem and the Solution

Untreated waste rock

Waste rock with NPR

Untreated waste rock

Waste rock with NPR

Bugs generally cause only trouble, but when fed, they are here to help!

A mining research group confirmed the presence of a biofilm on rocks from our

experiment in 2008.

• It is presently being tested on other waste rock by the same group.

• Do you want to reduce Acid Generation? • What are you waiting for. We are ready to

work with you?