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Sorting Technologies for CCA Treated Wood. Objective. To design and implement an automated system to effectively sort CCA treated wood from other wood types at facilities such as C&D facilities. Automated System. Designed using x-ray fluorescence technology or
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Objective To design and implement an automated system to effectively sort CCA treated wood from other wood types at facilities such as C&D facilities
Automated System • Designed using x-ray fluorescence technology or • Designed using laser induced breakdown spectroscopy technology
Motivation • CCA treated wood => ~ 6 % of all wood waste at C&D facilities • Amounts of CCA treated wood at C&D facilities increasing • At 6 % level, cannot be used as mulch or burned to generate fuel
Sorting Studies • Chemical stain method • laboratory results • field results from pilot studies • X-ray fluorescence (XRF) • laboratory results • Laser Induced Breakdown Spectroscopy (LIBS) • laboratory results
Automated System • X-ray fluorescence • Laser induced breakdown spectroscopy • Training and monitoring • chemical stains
Chemical Stains • Chrome Azurol S • PAN Indicator • Rubeanic Acid
Performance on whole wood 0.6 pcf 0.25 pcf 2.5 pcf
Current Practical Applications • Sorting Small Quantities of Treated from Untreated Wood • Screening Fuel Quality • Training Tool
Cost Estimate - Shelter • Trident $9,600 - $11,500
Update on Building • Tasks & Timeline • Current Contacts
Timeline Get Building ContractorUnder Contract 1 Wk 2 Wk 1 Wk 3 D 4-6 Wks Building ContractorDevelops Design Drawing Team ReviewsDesign ? Wks Building ContractorSeals Building Design Apply for Permit Building Fabrication Concrete Slab Erect Building
Building Contractors Contacted • Trident -- Met with on June 7 • Estimate: $9,600 - $11,500 • Anderson and Ellis Construction • Job too small • Bob Howard Construction • Contacted • John F. Swift, Inc. • Contacted
Concrete Contractors Contacted • Fred Derr Concrete • Prestige Concrete • John F. Swift
Conveyor Design #1 Movable holding arm Wood Piece Table
Movable holding arm Wood Piece Table Top View 3/4 “ to 2”
Movable holding arm Wood Piece Conveyor Surface X-rays Detector mounting Cross-Sectional View
Cost Estimates – Conveyor • American Conveyor, Miami $11,038 • Powerscreen, Lakeland $24,500
Conveyor Design #2 Holding arm Wood Table X-ray
Top View Wood Table
XRF • Based on emission of x-rays • Characteristic x-ray emitted by the element is read by the instrument
Model 400 • No special training required • User friendly • Printout or output easy to read and understand Analyzer Head
XRF Instruments • Low maintenance, few consumables, easy cleaning • No repetitive calibration necessary (6 mo. to 2 yrs.) • Life span of 10 years
XRF Instrument • Cost range from $20,000 - $100,000 • Detector replacement cost of $1,800 - $2,400 (life span of 5 years) • Licensing may be required • Sensor protected by a small beryllium window ($100 for replacement)
Results of XRF Studies • Arsenic is the best indicator metal, although all three metals can be analyzed for • Optimum count time of 2 seconds, would be even less for on-line analysis 1,800 ft/hr for detection of 1-ft board (2 s) 3,600 ft/hr for detection of 1-ft board (1 s) • Detection of CCA for Model 400 is possible at 1 inch distance with a plastic shield
X-Ray Technology • Analysis Time < 2 seconds • Best Metal for Analysis, As • Largest Separation Between Sample and Detector is 1 inch
XRF - Collaboration • ASOMA Inc (1 inch diameter face & strip model) • Jordan Valley (Hand-held unit, 3 in x 3 in face)
Laser Technology • Analysis Time < 1 second • Best Metal for Analysis, Cr • Tolerance, 12 inches
Experiments with LIBS • Sample 1: 0.25% CCA • Sample 2: 2.5% CCA • Sample 3: Weathered CCA • Sample 4: Weathered Utility Pole • Sample 5: New untreated • Sample 6: Weathered untreated