INTEGRATED PROCESSES FOR TREATMENT OF BERKELEY PIT WATER

INTEGRATED PROCESSES FOR TREATMENT OF BERKELEY PIT WATER

ACTIVITY III, PROJECT 21

BACKGROUNDBACKGROUND

The Berkeley Pit (Butte, Montana) - is currently filling at a rate of 3 million gallons per day of acidic, metals laden water

EPA issued a Record of Decision in 1994; the Berkeley Pit will be allowed to fill until approximately 2021, at which time the water level will approach the Critical Water Level

BACKGROUND (cont.)BACKGROUND (cont.)

Treatment technologies will be revisited approximately 2009; treatment required essentially forever

ROD designated hydroxide precipitation with aeration (followed by reverse osmosis if necessary) as preferred treatment technology

Over 1000 tons per day of dewatered sludge will be produced

PROJECT CONCEPTPROJECT CONCEPTValue of contained metals presents opportunity for

offsetting treatment costs via product recovery/resale

Acid mine drainage a worldwide problem

Project will evaluate both proven and new technologies for optimizing overall economics of producing compliant water

PROJECT CONCEPT (Cont’d.)PROJECT CONCEPT (Cont’d.)

All aspects of problem will be included

ChallengesDistance of Butte, Montana from marketsDilute feed stream (though extremely contaminated) Low-value base metals present

CURRENT PROJECT SCOPECURRENT PROJECT SCOPE

Develop two optimized flowsheets Water Treatment-Only Water Treatment-Plus-Product Recovery If results economically attractive, pursue pilot testing of optimized product recovery process at Berkeley Pit

CURRENT PROJECT SCOPE (Cont’d.)CURRENT PROJECT SCOPE (Cont’d.)

Major TasksPrepare standardized cost-estimating methodologyDevelop optimization strategy (identify/prioritize potential process improvements)

PROJECT STATUS AS OF APRIL 2000PROJECT STATUS AS OF APRIL 2000

Work plan complete Conceptual design of sludge repository complete Cost estimating methodology document complete Document verifying technical and cost aspects of

reference flowsheets complete Optimization strategy in development Preliminary optimization efforts underway (gathering

cost/technical data applicable to both flowsheets)

PROJECT SCHEDULEPROJECT SCHEDULE

Final report describing optimized flowsheets due for publication in November 2000

IMPROVEMENTS IN ENGINEERED BIOREMEDIATION OF ACID MINE DRAINAGE

Activity III, Project 24

IMPROVEMENTS IN ENGINEERED BIOREMEDIATION OF ACID MINE DRAINAGE

Activity III, Project 24

Project ObjectivesProject Objectives Objectives for improvements of engineered features of a passive SRB-bioreactor include:Selection of media Design of a permeability and contact time

enhancing system (PACTES),Design of an organic carbon replaceable

cartridge system (RCS),Development of computer software to model

SRB bioremedial processes in the bioreactor.

Scope of WorkScope of Work

The scope of work of the project includes seven tasks:

Task ISelection of organic carbon media that:

is permeable when saturated with water,

contains sufficient mass of organic carbon to minimize treatment rates, and

Could be economically used for passive SRB bioreactors.

Scope of Work, cont.Scope of Work, cont.

Task II PACTES design, evaluation through a bench test

study, and implementing it in the field.

Task III Designing of an organic carbon RCS that would

be easy to install and replace in a bioreactor at a remote location.

Scope of Work, cont.Scope of Work, cont.

Task IV

Development or adaptation of computer software to model SRB bioremedial processes in the bioreactor.

This task includes efforts on: Software development and validation Lab experiments for bioreaction kinetics

Scope of Work, cont.Scope of Work, cont.

Task V Implementation of the results of the four

previous tasks in a bioreactor constructed for this purpose.

Task VI Project management activities.

Task VII Site selection and characterization

Status of Work(as of 03/31/00)Status of Work(as of 03/31/00)

Task I was initiated in February, 2000.

Data base structure is 60% developed.

Search of information is advanced approximately 30%.

SLUDGE STABILIZATIONSLUDGE STABILIZATION

Activity IV ; Project 2

OBJECTIVEOBJECTIVEFormation, properties and stability of sludge

generated during treatment of acid mine waste waterPhysically and chemically characterize sludgesStudy the stability of sludges created by treatment

techniquesApply to acid mine water

Point sourceNon-point source

Stabilization Techniques will be Developed for Hazardous Sludge

Stabilization Techniques will be Developed for Hazardous Sludge

Commonly used additives for metallurgical waste solids

Thermal ProcessingEffective for arsenic bearing waste

Recovery of metal values or removal of hazardous constituent/recycling to metallurgical processes

In particular, sulfide sludge

DEMONSTRATION OF ARSENIC REMOVAL TECHNOLOGY

DEMONSTRATION OF ARSENIC REMOVAL TECHNOLOGY

Activity IV ; Project 5

OBJECTIVESOBJECTIVES

Remove Arsenic from Solution

Characterize Solid Products

Determine Stability During Storage

CONCEPTCONCEPT

Produce an apatite mineral-like structure with the substitution of arsenate for phosphate in the structure

REMOVAL OF ARSENIC FROM WASTE SOLUTIONSREMOVAL OF ARSENIC FROM WASTE SOLUTIONS

WHAT IS WRONG WITH SIMPLE LIME PRECIPITATION??

EPA’s BDAT FOR As BEARING WASTEWATERSEPA’s BDAT FOR As BEARING WASTEWATERS

Ferrihydrite precipitation is an adsorption phenomena

Potential ProblemLong-term storage

ASARCO DEMO RESULTSASARCO DEMO RESULTS

Scrubber Blowdown Water>3,000,000 ppb As to <10ppb As

Thickener Overflow6,000 ppb As to <15 ppb

Long-term Aging Presently Being Conducted (ASARCO and Mineral Hill Products)

MINE WASTE BERKLEY PIT LAKE CHARACTERIZATION PROJECT

MINE WASTE BERKLEY PIT LAKE CHARACTERIZATION PROJECT

Activity IV ; Project 8

CHARACTERIZATION PROJECTSCHARACTERIZATION PROJECTS

DEPTH PROFILESORGANIC CARBONSRB ACTIVITY IN SEDIMENTSSURFACE WATER REACTION KINETICS

SUMMARYSUMMARY

Berkley Pit Lake system is complex and requires much more research to fully understand

Knowledge gained through work on Berkley Pit may be used on other pit lakes through out the world

Artificial Neural Networks As An Analysis Tool for Geochemical Data

Artificial Neural Networks As An Analysis Tool for Geochemical Data

Activity IV ; Project 14

WHY USE NEURAL NETWORK?

TO SORT THROUGH OR ANALYZE VERY LARGEDATA VOLUMES

NN’s basically think like the human brain

ALGAL REMEDIATION DATA OF BERKELEY PITALGAL REMEDIATION DATA OF BERKELEY PIT

4 Classes of Data with 15 SamplesWithin each class, 5 subclasses exist with

3 samples each

Self- Organizing MapSelf- Organizing Map

Groups Data According to Trends Within the Data

For Algae, the SOM Output Compared to Known Data Classes

NOTE: Neural Networks can also be used to predict data

Future Possibilities for NN Analysis of AlgaeFuture Possibilities for NN Analysis of Algae

Look for behavior trend within Algae speciesCompare similarities and differencesTrain network to recognize different Algae

species and concentrationsDevelop network to predict Algae types and

concentrations from pit-water metal concentrations