FLOAT AND SINK PROFICIENCY TESTING REPORT SEVENTEEN · FLOAT AND SINK PROFICIENCY TESTING REPORT...

THINKING QUALITY, QUALITY THINKING REGISTRATION NUMBER: 2006/149731/23 (RMB INDUSTRIAL STATIONERS cc t/a)

81 CERAMIC CURVE, ALTON, RICHARDS BAY 3900 l TEL: +27(0)35 751 2446 l CEL: +27(0)83 6500151 l FAX: 0862605793 E-MAIL: [email protected]

FLOAT AND SINK PROFICIENCY TESTING

REPORT SEVENTEEN

Revision: 00

Final report

FEBRUARY 2020

R BABOOLAL (SCHEME MANAGER)

PARTICIPANT:

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EXECUTIVE SUMMARY

1. Sixteen samples were sent out to participants with 15 result submissions.

2. Since most of the results do not follow a Normal distribution, non-parametric statistics were used. This is

a straightforward statistical calculation and can be found on the link below

https://www.youtube.com/watch?v=qkI-HeMiKzQ

3. Observations at the differing densities

DENSITY COMMENTS

1.30 Three laboratories obtained yields at this density. The data obtained for these is not sufficient to carry out reliable statistical analysis. The typical ash for this coal round had an ash of around 30%, hence not much yield was expected

1.40 All participants reported yields at this density, however the results obtained were quite varied. Three outliers were detected on the yields and two on the ash determination. The standard deviation on the yields was low, after the exclusion of outliers. Standard deviation on the ash was high at 2.43.

1.50 The yields were varied, but no outliers detected. The sample preparation and ash determination were also quite varied 2.79

1.60 There was one outlier each, on the yields and the ash determination with the standard deviations still high on both

1.70 The yields had a high standard deviation whereas the ash standard deviation was reduced, indicating greater accuracy on the ash determined at this yield

1.80 At this density as well, the yields had a high standard deviation whereas the ash standard deviation was reduced, indicating greater accuracy on the ash determined at this yield

Sink 1.80 No outliers detected; however varied results obtained. Generally, particularly good results all round considering that this was not a high-grade coal.

https://www.youtube.com/watch?v=qkI-HeMiKzQ

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TABLE OF CONTENTS

ITEM

PAGE NUMBER

Letter to participant

4

List of participants

5

Type of sample used

5

Preparation of sample

5

Yields and Ash results at density 1.30

6


7


8


9


10


11

Yields and Ash results at sink 1.80

12

Conclusion

13

Terms and conditions

13

of 15 Dear Participant

Thank you for your participation in the Coal Concepts Float and Sink February 2020 proficiency testing scheme.

Your laboratory code is Xf

All results are totally confidential. Any results in bold, italics, underlined are outliers

Please take note of the following:

Non-parametric statistics were used to assess results since most data do not follow a Normal or Gaussian

distribution. Therefore the calculation of outliers was done using the box and whisker plot. It also does not make

sense to calculate z-scores due data variance and limitation.

All calculations can be made available upon request

The Coal Concepts scheme adheres to the requirements of ISO/IEC 17043: Conformity assessment – General

requirements for proficiency testing.

Best Regards

R Baboolal

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LIST OF PARTICIPANTS IN ALPHABETICAL ORDER

Bureau Veritas Inspectorate Laboratories - Middelburg

Bureau Veritas Inspectorate Laboratories - Tendele

Bureau Veritas Trading & Inspection SA - PTA

Bureau Veritas Inspectorate Laboratories – ZAC Mine

Bureau Veritas Inspectorate Laboratories – Moatize, Tete

CoalLab - Middelburg

CoalLab - Phola

Intertek - Mozambique

Noko Analytical Services - Witbank

SABS Secunda Laboratory

Sibonisiwe Coal Laboratory Services

Siza Laboratory Services - Middelburg

Umzamo Analytical Services

Vitrovian Analytical Services

Zululand Anthracite Colliery

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1. TYPE OF SAMPLE USED

The coal used in this proficiency testing round was washed bituminous coal with high ash.

2. PREPARATION OF SAMPLE

Approximately 200kg’s of sample with an approximate topsize of 50mm was sourced. This was crushed to

approximately 12 mm using a jaw crusher. The bulk sample was mixed on a concrete floor using a spade.

Eighteen by 10l buckets were placed near the bulk samples. Using the spade, small increments of the bulk

sample were placed into each of the buckets. This was done until all the buckets contained about 10kgs of

coal.

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3. RESULTS

3.1 YIELDS AND ASH RESULTS AT DENSITY OF 1.30

COAL CONCEPTS - PROFICIENCY TESTING - FEBRUARY 2020

ANALYTICAL PARAMETER : YIELDS AT F1.30

LAB ID MASS (Kg) %YIELD

6f 0.03 0.30

8f 0.28 2.97

23f 0.08 0.82

NUMBER OF RESULTS - 3 3

OUTLIERS - - 0

AVERAGE - - 1.36

STD DEVIATION - - 1.42

MEDIAN - - 0.82


ANALYTICAL PARAMETER : ISO ASH (%) (Density at 1.30)

LAB ID

MOISTURE IN ANALYSIS SAMPLE (%) AIR DRY DRY BASE

6f 1.20 11.40 11.54

8f 2.60 15.28 15.69

23f 1.77 14.66 14.92

NUMBER OF RESULTS - 3 3 -

OUTLIERS - - - 0

AVERAGE - 1.86 13.78 14.05

STD DEVIATION - - 2.08 2.21

MEDIAN - - 14.66 14.92

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3f 0.14 1.40

5f 0.13 1.30

6f 0.28 2.80

7f 0.32 3.30

8f* 0.69 7.06

11f 0.18 2.32

14f 0.08 0.79

15f 0.16 1.60

18f 0.18 1.90

19f 0.30 3.00

20f 0.08 1.10

21f 0.20 2.10

23f* 0.78 7.98

24f* 0.57 13.10

NUMBER OF RESULTS - 14 14

OUTLIERS - 3

AVERAGE - - 1.96

STD DEVIATION - - 0.82

MEDIAN - 2.00



LAB ID

MOISTURE IN ANALYSIS SAMPLE (%) AIR DRY DRY BASE

3f 1.70 5.40 5.49

5f 1.20 8.90 9.01

6f 1.20 13.20 13.36

7f 2.00 10.00 10.20

8f* 2.60 16.31 16.75

11f 1.80 7.20 7.33

14f 1.82 5.20 5.30

15f 1.30 6.70 6.79

18f 1.50 6.90 7.01

19f 1.60 6.90 7.01

20f 1.50 5.90 5.99

21f 1.60 6.20 6.30

23f* 1.58 16.31 16.57

24f 1.70 10.30 10.48 NUMBER OF RESULTS - 14 14 14 OUTLIERS - 2 AVERAGE - 1.65 7.73 7.86 STD DEVIATION - - 2.40 2.43 MEDIAN 6.90 7.01

Non parametric stats on Yield results Non parametric stats on DB results

Quartile 1 1.40 Quartertile 1 6.30



INTERQUARTILE RANGE (IQR) 1.90


1.5 X IQR 2.85 1.5 X IQR 6.06

Acceptable lower limit -1.45 Acceptable lower limit 0.24

Acceptable upper limit 6.15 Acceptable upper limit 16.40

Results outside acceptable limits 8f, 23f, 24f

Results outside acceptable limits 8f, 23f

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3f 0.84 8.60

5f 1.09 11.20

6f 1.37 13.70

7f 1.38 14.00

8f 0.60 6.14

11f 0.93 11.97

14f 0.84 8.68

15f 1.19 12.00

18f 1.00 10.60

19f 1.00 10.00

20f 0.71 9.90

21f 1.06 11.00

23f 0.80 8.18

24f 0.60 13.80 NUMBER OF RESULTS - 14 14 OUTLIERS - - 0 AVERAGE - - 10.70 STD DEVIATION - - 2.32 MEDIAN - - 10.80



LAB ID MOISTURE IN ANALYSIS SAMPLE (%) AIR DRY DRY BASE

3f 1.90 13.10 13.35

5f 1.00 15.80 15.96

6f 1.10 18.00 18.20

7f 2.40 20.20 20.70

8f 2.90 21.31 21.95

11f 1.50 15.00 15.23

14f 1.86 12.60 12.84

15f 1.40 14.90 15.11

18f 1.30 14.60 14.79

19f 1.40 14.40 14.60

20f 1.50 13.30 13.50

21f 1.80 13.30 13.54

23f 1.56 17.32 17.59

24f 1.80 17.30 17.62

NUMBER OF RESULTS - 14 14 14

OUTLIERS - - 0

AVERAGE - 1.67 15.80 16.07


MEDIAN 14.95 15.17

Non parametric stats on yield results Non parametric stats on DB results

Quartile 1 8.68 Quartile 1 13.54





1.5 X IQR 4.98 1.5 X IQR 6.11

Acceptable lower limit 3.70 Acceptable lower limit 7.43


Results outside acceptable limits 0


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3f 1.90 19.40

5f 1.68 17.20

6f 1.79 18.00

7f 1.43 14.60

8f 2.13 21.80

11f 1.66 23.90

14f* 0.20 2.01

15f 1.91 19.10

18f 1.85 19.60

19f 2.00 20.10

20f 1.31 18.10

21f 1.93 19.90

23f 1.56 15.95

24f 0.90 20.70 NUMBER OF RESULTS - 14 14 OUTLIERS - - 1 AVERAGE - - 19.10 STD DEVIATION - - 2.43 MEDIAN - - 19.40




3f 1.70 20.40 20.75

5f 1.30 23.50 23.81

6f 1.90 25.30 25.79

7f 1.90 21.30 21.71

8f 2.90 24.05 24.77

11f 1.90 23.90 24.36

14f 2.03 20.60 21.03

15f 1.60 23.60 23.98

18f 1.00 22.60 22.83

19f 1.52 15.20 15.43

20f 1.80 21.70 22.10

21f 1.80 22.40 22.81

23f 1.86 22.67 23.10

24f 1.70 22.40 22.79


OUTLIERS - - - 1

AVERAGE - 1.79 22.65 23.06


MEDIAN - 22.60 22.83







1.5 X IQR 4.80 1.5 X IQR 3.41



Results outside acceptable limits 14f


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3f 2.28 23.20

5f 2.35 24.10

6f 2.09 21.00

7f 2.14 21.70

8f 1.57 15.97

11f 1.27 16.34

14f 2.41 24.76

15f 1.82 18.20

18f 2.22 23.50

19f 1.90 29.50

20f 1.54 21.40

21f 1.89 19.50

23f 1.87 19.12

24f 0.73 16.80 NUMBER OF RESULTS - 14 14 OUTLIERS - - 0 AVERAGE - 1.95 21.08 STD DEVIATION - 0.34 3.78 MEDIAN 1.90 21.20




3f 2.30 28.00 28.66

5f 1.70 29.10 29.60

*6f 1.50 21.80 22.13

7f 2.10 29.80 30.44

8f 3.60 30.50 31.64

11f 2.20 30.10 30.78

14f 2.42 27.80 28.49

15f 1.80 30.30 30.86

18f 1.70 28.90 29.40

19f 1.90 29.50 30.07

20f 2.00 28.40 28.98

21f 2.00 28.80 29.39

23f 2.01 29.32 29.92

24f 1.30 26.60 26.95


OUTLIERS - - - 1

AVERAGE - 2.09 28.49 29.63


MEDIAN 29.00 29.60







1.5 X IQR 7.95 1.5 X IQR 2.67





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3f 1.81 18.50

5f 2.06 21.10

6f 1.66 16.70

7f 2.01 20.40

8f 2.43 24.87

11f 1.92 24.71

14f 2.86 29.43

15f 1.80 18.10

18f 1.48 15.60

19f 1.80 18.10

20f 1.36 18.90

21f 1.73 17.90

23f 2.25 23.01

24f 0.79 18.20 NUMBER OF RESULTS - 14 14 OUTLIERS - 0 AVERAGE - - 20.39 STD DEVIATION - - 3.84 MEDIAN - - 18.70




3f 2.70 33.10 34.02

5f 2.70 35.20 36.18

6f* 4.00 37.00 38.54

7f 3.10 33.10 34.16

8f 4.40 35.36 36.99

11f 3.80 33.90 35.24

14f 2.83 32.60 33.55

15f 2.40 33.70 34.53

18f 1.60 34.50 35.06

19f 2.40 33.90 34.73

20f 2.20 32.80 33.54

21f 2.20 34.70 35.48

23f 2.91 33.71 34.72

24 1.20 32.90 33.30


OUTLIERS - - 1 1

AVERAGE - 2.86 33.81 34.73


MEDIAN - - 33.71 34.72







1.5 X IQR 7.37 1.5 X IQR 2.19

Acceptable lower limit 10.74


Acceptable upper limit 30.38




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3.7 YIELDS AND ASH RESULTS AT DENSITY OF SINK 1.80


ANALYTICAL PARAMETER : YIELDS AT Si 1.80


3f 2.83 28.90

5f 2.44 25.00

6f 2.40 24.10

7f 2.56 26.10

8f 2.07 21.20

11f 1.92 24.71

14f 3.34 34.34

15f 3.11 31.20

18f 2.73 28.90

19f 3.21 32.20

20f 2.21 30.60

21f 2.87 29.60

23f 2.44 24.95

24 0.75 17.30 NUMBER OF RESULTS - 14 14 OUTLIERS - - 0 AVERAGE - - 27.08 STD DEVIATION - - 4.61 MEDIAN - - 27.50


ANALYTICAL PARAMETER : ISO ASH (%) (Sink portion after density1.80)


3f 2.70 45.40 46.66

5f 2.20 47.60 48.67

6f 1.50 48.10 48.83

7f 2.60 46.60 47.84

8f 3.50 47.78 49.51

11f 2.90 47.20 48.61

14f 2.65 43.70 44.89

15f 2.40 44.40 45.49

18f 2.20 44.70 45.71

19f 2.70 44.60 45.84

20f 2.10 44.10 45.05

21f 2.20 44.50 45.50

23f 2.41 45.76 46.89

24f 1.90 42.00 42.81


OUTLIERS - - - 0

AVERAGE - 2.54 45.46 46.59


MEDIAN - - 45.05 46.25







1.5 X IQR 8.84 1.5 X IQR 4.68





Results outside acceptable limits

0


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4. HOMOGENEITY CHECK

SAMPLE NO.

TEST PORTION

1

TEST PORTION

2 sample av (Xt)

range (Wt)

range sqd

1 30.46 30.18 30.32 0.28 0.0784

2 30.86 30.72 30.79 0.14 0.0196

3 30.17 30.17 30.17 0.00 0.0000

4 30.3 30.38 30.34 0.08 0.0064

5 30.39 30.76 30.58 0.37 0.1369

6 30.04 30.11 30.08 0.07 0.0049

7 30.8 30.89 30.85 0.09 0.0081

8 30.35 30.82 30.59 0.47 0.2209

9 30.16 30.29 30.23 0.13 0.0169

10 30.37 30.11 30.24 0.26 0.0676

GENERAL AVERAGE 30.42 STANDARD DEVIATION 0.266 WITHIN SAMPLE STANDARD DEVIATION 0.167 BETWEEN SAMPLE STANDARD DEVIATION 0.238

5. STABILITY CHECK

SAMPLE NO.

TEST PORTION

1

TEST PORTION

2 sample av (Xt)

range (Wt)

range sqd

1 30.09 30.66 30.38 0.57 0.3249

2 30.19 30.01 30.10 0.18 0.0324

3 29.98 30.11 30.05 0.13 0.0169

4 30.03 29.94 29.99 0.09 0.0081

5 30.5 30.02 30.26 0.48 0.2304

6 30.36 29.88 30.12 0.48 0.2304

7 30.3 29.9 30.10 0.40 0.1600

8 30.16 30.6 30.38 0.44 0.1936

9 30.56 30.07 30.32 0.49 0.2401

10 30.5 30.35 30.43 0.15 0.0225

GENERAL AVERAGE 30.21 STANDARD DEVIATION 0.158 WITHIN SAMPLE STANDARD DEVIATION 0.270 BETWEEN SAMPLE STANDARD DEVIATION 0.107

The Float and sink samples were confirmed to be sufficiently homogenaous and stable, for analysis to be

done

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6. CONCLUSION Generally acceptable/comparable results were obtained.

The ash results were very good considering this is obtained from a washed fraction (sampling). (If the compounding contributions

from sample preparation and testing errors are taken into account as well.)

The use of non-parametric statistics had been applied

COAL CONCEPTS: Terms and Conditions

Return of results: Laboratories participate in proficiency testing programs on the understanding that they will be sharing their results and information anonymously with other laboratories performing the same analysis. No return of results compromises the spirit of the programs, and reports will not be sent to laboratories unless they return results. Payment in full is required from all laboratories enrolling whether they return results or not. Errors in Participant Proficiency Testing Results: Proficiency testing reports should reflect the level of accuracy that a regular testing client would receive. If a participant finds an error in their proficiency testing results, they may notify us in writing and change their submission PRIOR to the due date for return. Changes after this time will not be accepted. Coal Concepts’ reports results as submitted by participants. On occasion, it seems as though participants have mixed up the samples or not processed the samples according to the instructions. Coal Concepts cannot make assumptions of this nature and change results 'to suit'. We also cannot compromise the integrity of the programs by suggesting to some participants that they should review their results prior to the due date. (This is unfair to other participants) It is the responsibility of the participants to check all aspects of the program, including sample identification, preparation, testing instructions, calculations and reporting of the results prior to results submission. If samples are not in good condition on arrival to the participant laboratory, Coal Concepts must be notified in writing IMMEDIATELY, as often samples can be replaced in good time. Claims about samples received in bad condition will not be accepted after the report has been issued. Late Enrolments and Late Results: Late enrolment requests cannot always be accommodated, as sample manufacture must be scheduled well in advance to the shipping date of the program to allow all necessary quality assurance activities to be carried out. Shipping of PT materials and evaluating test results from PTPs out of cycle with the mainstream programs is considerably time consuming and therefore costly. In order not to disadvantage participants able to comply with time frames, Coal Concepts may charge a late fee in the following circumstances: Requests that Coal concepts staff enters results on behalf of participants Requests to record results after the due date Requests for PTP participation that is out of cycle with the scheduled dates Shipping fees and Customs clearance: Costs incurred for shipping samples and clearance of same through customs are the responsibility of the participating laboratory unless otherwise indicated Non-payment of fees: Coal Concepts retains the right to withhold reports and/or test materials and services when invoices are outstanding. Confidentiality of results: All data and information received by Coal Concepts from its clients are considered confidential unless the client has given express permission to pass on information. Definitions: The dictionary definitions of “collusion” and “falsification” are as follows. · Collusion: A secret agreement or cooperation for a fraudulent or deceitful purpose. · Falsification: Deliberately changing something to be false. In proficiency testing terms, collusion is comparing data (and perhaps changing data) to fit in with a believed “correct” result. This is contrary to the spirit of proficiency testing programs, which are issued with the intention of providing an objective comparison of a laboratory’s performance with others. Coal Concepts tries to minimise the occurrence of collusion by being aware that laboratories should be objective when they report their results, and should therefore not know the intended results at the time they are reporting to us. Answers are not provided to clients until results have been submitted. To prevent collusion and falsification our advice to clients is: DON’T confer with others about PT samples or results. DO accept the fact that everyone makes errors. DON’T average the results or opinions of every person in the laboratory before selecting the answer to be submitted. Instead, use one of the answers AS SUBMITTED to you and take advantage of the Coal Concepts internal QA services and submit all answers generated by the technicians. DO have confidence in your own results. Proficiency Testing (PT) is a compulsory part of laboratory accreditation, but it is also an important tool for giving you confidence in your results. “Enhancing” your PT results with assistance from another participant cannot increase confidence in your laboratory’s performance. Coal concepts’ testing staff are not told what the expected results are, nor what we are expecting. We subject ALL results to analysis, even if they are different. The staff have the right to check that the results we enter on their behalf are correctly transcribed. Clients are always welcome to contact Coal Concepts to seek advice or information about collusion or falsification of data. Policy for Participant Appeal of PT Performance Assessment: If participants disagree with their performance assessment in a proficiency report, they should inform Coal Concepts in writing. The response will include Coal Concepts interpretation of the outcome of the reassessment and an explanation of that outcome. (For example, explanation of a calculation, or the rationale for the outcome of the evaluation.) If a mistake has been made by Coal Concepts, it will be dealt with via Coal Concepts’ non-conformance system. Liability In no event shall a party's liability to the other party for direct damages exceed an amount equal to the value of the amount for the PT Programme, under that specific month

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