Presentation on theme: "Boojum Research LTD - 25 years of Ecological Engineering Invited by West Virginia Mine Drainage Task Force Symposium Morgantown, March 2011 M. Kalin and."— Presentation transcript:
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 ?
Boojum Research LTD - 25 years of Ecological Engineering Margarete Kalin/Boojum Research LTD President and founder of Boojum Research LTD Adjunct professor at U of Toronto, Ryerson University, U of Windsor, Queens 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 Company is 29 years old, with contracts worldwide. Canadian contracts only shown
Boojum Research LTD - 25 years of Ecological Engineering it utilizes the dynamics of well-adapted organisms within MWWMA – no extra space needed identifies those factors blocking the way to ecosystem growth targets those locations within the MWWMA (sediment, rock surfaces or the AMD water) with applications of essential elements to promote growth (e.g. organic carbon, phosphate etc.) ECOLOGICAL ENGINEERING aims to practically and beneficially apply knowledge of how ecological systems operate on the mineral and rocks surfaces within these landforms
1838 Ehrenberg Gallionella ferruginea with ochreous deposits of bog iron Winogradsky Beggiatoa oxidation H2S to elemental sulfur; Leptothrix ochracea oxidation of FeCO3 to ferric oxid 1919 Harder microbial iron oxidation and precipitation in iron sedimentary deposits. Stutzer (1911) Vernadsky ( ) 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 pHFeSAcidityCond NO PHOSPHATE* Cycle Cycle Cycle Amendments all types including North Carolina phosphate min – max pHFeSAcidityCond Cycle 1**1.8 – – – – Cycle 22.8 – – – 4938 – – 2.36 Cycle 32.8 – 3.58 – – 1.4
Field experiment Fill # Tons shale/coal (parting) Fill # Tons shale/coal l with 1.14 tons of apatite rock Fill # Tons shale/coal with.55 tons of apatite rock Results were good – but did not make sense – so lets 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 reported on the cessation leaching of Cu from a dump in B.C. Sample obtained in 1992 Boojum Research LTD - 25 years of Ecological Engineering 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 practical It has to be suistainable – lasting for ever It has to be general – i.e. work in all types of wastes
NPR Code 48 4 mm to < 0.04 mm Relating the Scale of the Observations Phosphate Rock Waste Rock 150mm150mmm
Boojum Research LTD - 25 years of Ecological Engineering
B- zone waste rock pile in distance with muskeg area in front Boojum Research LTD - 25 years of Ecological Engineering B-zone waste rock pile
Boojum Research LTD - 25 years of Ecological Engineering B-zone waste rock pile LOAD IN SEEPAGES AsFeS Annual Load % Leached from pile%/year Years to exhaustionyear Maximum elemental concentrations in Rock and Secondary Precipitate AsFeS Whole Rock mg.g n=97 WRP-P Precipitate mg.g 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 )
Tailings Surface Cover Development through Integration of Reactive Phosphate and Organic Matter (PHITO) Boojum Research LTD - 25 years of Ecological Engineering
integrate nutrients, precipitation agents and NPR below the roots, then grow organics
Stanrock: Horse Manure and Natural Phosphate Rock 1995 Boojum Research LTD - 25 years of Ecological Engineering Heterotroph Oxygen Requirements Heterotrophs counted fresh tailings: 10 7 /g Populations oxygen requirement: 175µL/g Oxygen present in fresh tailings: < 20 µL/g
Boojum Research LTD - 25 years of Ecological Engineering 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 % sulphide left in field years monitor the pore water metal acidity TAILINGS AREA – Inco: 2700m 2 ; Stanrock:432 m 2 Test NPR additions to waste rock 4-15 % sulphide left outdoors 2.7 years monitor the effluent metal acidity Monitoring 1.8
Boojum Research LTD - 25 years of Ecological Engineering Results of the waste rock drums
pH profile for low pyrite Stable layer Boojum Research LTD - 25 years of Ecological Engineering Unstable layer no matter what amount of pyrite – acid rock drainage is with you !
UraniumPyhrrotitePolymetalicWaste rock Elements (mg.L -1 ) ControlNPRControlNPRControlNPRControlNPR N=1 N=2 N=3N=6 Fe P S pH Acidity (mgCaCO 3.L -1 ) 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 Boojum Research LTD - 25 years of Ecological Engineering r = (±0.86). Eh 12.93(±1.04). pH 1.0(±0.29) (1) log r =-19.71(±0.86) (±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 % Ca (as CaCO 3 )
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%) %9.246% %35.571% Coarse Sand (52.0%) %44.902% %5.455% %0.944% %0.652% Medium Sand (2.2%) 2.600%0.630% %0.781% %0.811% Fine Sand (0.7%) 0.736%0.271% %0.336% %0.130% Silt (0.3%) 0.176%0.094% %0.060% %0.051% <400< %0.065%
MACRONUTRIENTS P (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 surface 4.We dissolved NPR in 0.1N sulphuric acid and only a fraction of it dissolved 5.WE HAD THE BIOLOGICAL ROLE OF NPR! - MICRONUTRIENTS 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 (1 st Observation) Boojum Research LTD - 25 years of Ecological Engineering 1995
Boojum Research LTD - 25 years of Ecological Engineering Figure 8 - (A) A2 SEM/EDS 2009 (rock 2); (B) A3 SEM/EDS Boojum Research and U of Toronto (ongoing research) After 3 years of outdoor exposure and 11 years of storage P S Au Fe 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 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?