quo vadis work package 4

Quo Vadis work package 4

Sampling and sample preparation

By Geert Cuperus (Tauw)TAUWVTTINFA INSTITUTE

Contents

• Background• The new standard• Validation of sampling and sample preparation• Ruggedness testing

Background

• Inhomogenity is the issue• Shape

•Variability in shape and size

• Occurance of substances•Many elements occur concentrated in particles•“99% of a substance in 1% of the SRF”•Subsamples keep containing such particles

Background

• Many types of SRF exist• Fluff as complex example• Sampling from static lots and stockpiles mostly occur• Sampling consists of a series of steps

Sampling Mass reduction Size reduction AnalysisMass reduction

The new standard – EN 15442

• Lot size (period of production)• Number of increments• Size of increments• Distribution of increments• Sample size

The new standard – EN15442

The new standard – EN 15442

• Minimum sample size:

pVC

pgDsM

2g

395m )(

)1(

6

π

Validation of sampling

• Procedure:•Five production sites•Samplers (5) apply EN15442 to draft a sampling plan•Sampling (duplicate) of selected batches•Evaluation of plans and sample performance by Tauw•Analysis of elements by one laboratory•Statistical analysis

Validation of sampling

Sampling at 5 sites

A B

Sampler 1 Sampler 2 Sampler 3 Sampler 4 Sampler 5

A B A B A B A B

Validation of sampling

SAMPLE PREPARATION• Samples to laboratory: < 5 kg.• Particle size < 30 mm.• Sample preparation = subsampling + comminution• WP4 investigated size reduction by

•Quartering•Splitting

Validation of sampling

Sample preparationQuartering

Validation of sampling

Sample preparationSplitting

Validation of sampling

Sample

SubsampleSubsample

Primary splitting or quartering

Secondary splittingor quartering

A1 A2 A3 A4

5 sites

Validation of sampling

• Field experience:•EN15442 was easy to understand and practicable•Some samplers indicated the standard is too extensive•Useful comments resulted•Proper sampling plans were drafted

Validation of sampling

Net calorific value Repeatability 2,3%

Reproducibility 3,1%

Chlorine Repeatability 20,5%

Reproducibility 23,4%

Antimony Repeatability 40,4%

Reproducibility 41,8%

Copper Repeatability 123%

Reproducibility 123%

Validation of sampling

2,

2,

2samplingextmeasurementotaltmeasurementotalsampling sss

Validation of sampling => total standard deviationValidation of sample preparation => minus sampling

Therefore:

Validation testing on sample preparationShare sampling in total repeatabilityParameter Site 1 Site 2 Site 3 Site 4

Dry matter 100% 86% 64% -826%

NCV 100% 97% -40% -150%

Chlorine -22675637% 52% -460% -1313%

Antimony -79900% -1500% -1018% -567%

Arsenic -602% -1393%All values equal

detecion limit 86%

Lead -1764% -272% -308% 87%

Cadmium -49640% 46% -133% -351%

Chromium 40% -336% -2350% 100%

Cobalt -6411% -2067% -843% 97%

Copper -1430 0 -2% 0

Manganese 52% -5114% 71% 80%

Nickel 94% -400% -1339% 100%

Mercury -4733628% 7%All values equal

detecion limit 100%

ThalliumAll values equal

detecion limitAll values equal

detecion limitAll values equal

detecion limitAll values equal

detecion limit

Vanadium 100% -247% 61% 96%

Validation of sampling

• Results were used to adjust EN15442• Practicable recommendations resulted• Errors of repeatability frequently higher than errors of

reproducibility• Repeatability variation frequently negative or >100%• Other sources of error therefore have larger influence

Ruggedness testing

• Several method parameters affect the reliability of

EN15442• Of these, the lot size and the number of increments

are considered most important

Ruggedness testing on samplingStructure of the investigation

• Preparation • Research topics

•Parameters: Cl, Hg, Cu, Cr •Sampling focused on influence number of increments

(12, 24, 36, 48 and 60)•Sampling focused on influence lot size (500, 1500, 2500,

3500)

• Field work at 4 sites (Italy, Norway, Germany, Belgium)

• Sample preparation & analysis• Calculation results and reporting

Ruggedness testing

Sampling at 4 sites

5 samples

A-E

12 increments 24 increments 36 increments 48 increments 60 increments

5 samples

A-E

5 samples

A-E

5 samples

A-E

5 samples

A-E

Ruggedness testing

Sampling at 4 sites

5 samples

A-E

500 ton 1.500 ton 2.500 ton 3.500 ton

5 samples

A-E

5 samples

A-E

5 samples

A-E

Ruggedness testing on sampling Results repeatability versus number of increments

0%

50%

100%

150%

200%

250%

300%

350%

400%

0 12 24 36 48 60

Number of increments

Rep

eata

bili

ty

Chlorine

Mercury

Copper

Chromium

Average Cl, Hg, Cu and Cr

Ash

Ruggedness testing on sampling Results repeatability versus lot size

0%

50%

100%

150%

200%

250%

300%

350%

400%

450%

500%

0 500 1000 1500 2000 2500 3000 3500 4000

Lot size

Rep

eata

bili

ty

Chlorine

Mercury

Copper

Chromium

Average Cl, Hg, Cu and Cr

Ash

Ruggedness testing

• Optimum lot size is 2.500 ton (based on Cl, Hg and

Cr)• Optimum number of increments is 36• However: neither of these parameters dominate the

quality of a sample• Therefore 24 increments and lot size 1/10 of annual

production can well be applied

Conclusion

• Much work has been done now• Go and try the standard for yourself!!

THANK YOU