ISO 20904:2020
Hard coal — Sampling of slurries
This document sets out the basic methods for sampling fine coal, coal rejects or tailings of nominal top size <4 mm that is mixed with water to form a slurry. At very high ratios of fine solids to water when the material assumes a soft plastic form, the mixture is correctly termed a paste. Sampling of pastes is not covered in this document.
The procedures described in this document primarily apply to sampling of coal that is transported in moving streams as a slurry. These streams can fall freely or be confined in pipes, launders, chutes, spirals or similar channels. Sampling of slurries in stationary situations, such as a settled or even a well-stirred slurry in a tank, holding vessel or dam, is not recommended and is not covered in this Document.
This document describes procedures that are designed to provide samples representative of the slurry solids and particle size distribution of the slurry under examination. After draining the slurry sample of fluid and measuring the fluid volume, damp samples of the contained solids in the slurry are available for drying (if required) and measurement of one or more characteristics in an unbiased manner and with a known degree of precision. The characteristics are measured by chemical analysis or physical testing or both.
The sampling methods described are applicable to slurries that require inspection to verify compliance with product specifications, determination of the value of a characteristic as a basis for settlement between trading partners or estimation of a set of average characteristics and variances that describes a system or procedure.
Provided flow rates are not too high, the reference method against which other sampling procedures are compared is one where the entire stream is diverted into a vessel for a specified time or volume interval. This method corresponds to the stopped-belt method described in ISO 13909-2.
| Get this standard | Prices exclude GST | |
|---|---|---|
| PDF ( Single user document) |
$281.74 NZD
|
|
| HardCopy |
$319.13 NZD
|
|
| Networkable PDF |
Price varies
|
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principles of sampling slurries
4.1 General
4.2 Sampling errors
4.2.1 General
4.2.2 Preparation error
4.2.3 Delimitation and extraction errors
4.2.4 Weighting error, EW
4.2.5 Periodic quality fluctuation error, EQ3
4.3 Sampling and overall variance
4.3.1 Sampling variance
4.3.2 Overall variance
5 Sampling schemes
6 Minimization of bias and unbiased increment mass
6.1 Minimizing bias
6.2 Volume of increment for falling stream samplers to avoid bias
6.3 Volume of increment for manual sampling to avoid bias
7 Precision of sampling and determination of increment variance
7.1 Overall precision
7.2 Primary increment variance
7.3 Preparation and testing variance
8 Number of sub-lots and number of increments per sub-lot
9 Minimum mass of solids in lot and sub-lot samples
9.1 General
9.2 Minimum mass of solids in lot samples
9.3 Minimum mass of solids in sub-lot samples
9.4 Minimum mass of solids in lot and sub-lot samples after size reduction
10 Time-basis sampling
10.1 General
10.2 Sampling interval
10.3 Cutters
10.4 Taking of increments
10.5 Constitution of lot or sub-lot samples
10.6 Division of increments and sub-lot samples
10.7 Division of lot samples
10.8 Number of cuts for division
11 Stratified random sampling within fixed time intervals
12 Mechanical sampling from moving streams
12.1 General
12.2 Design of the sampling system
12.2.1 Safety of operators
12.2.2 Location of sample cutters
12.2.3 Provision for duplicate sampling
12.2.4 System for checking the precision and bias
12.2.5 Minimizing bias
12.3 Slurry sample cutters
12.3.1 General
12.3.2 Falling‑stream cutters
12.3.3 Cutter velocities
12.4 Mass of solids in increments
12.5 Number of primary increments
12.6 Routine checking
13 Manual sampling from moving streams
13.1 General
13.2 Choosing the sampling location
13.3 Sampling implements
13.4 Mass of solids in increments
13.5 Number of primary increments
13.6 Sampling procedures
14 Sampling of stationary slurries
15 Sample preparation procedures
15.1 General
15.2 Reduction mills
15.3 Sample division
15.4 Chemical analysis samples
15.5 Physical test samples
16 Packing and marking of samples
Annex A (informative) Examples of correct slurry devices
Annex B (informative) Examples of incorrect slurry sampling devices
Annex C (normative) Manual sampling implements
Bibliography
Previous versions
Keep me up-to-date
Register to receive notifications when updates are made to this standard.
Related Information
Similar Standards
-
BS 3553:1992
Specification for graphical symbols for coal preparation plant flowsheets
-
BS 7530-1:1992
Methods for froth flotation testing of hard coal, Laboratory procedure
-
BS 7530-2:1995
Methods for froth flotation testing of hard coal, Evaluation of flotation characteristics
-
BS ISO 10086-1:2019
Coal. Methods for evaluating flocculants for use in coal preparation, Basic parameters
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principles of sampling slurries
4.1 General
4.2 Sampling errors
4.2.1 General
4.2.2 Preparation error
4.2.3 Delimitation and extraction errors
4.2.4 Weighting error, EW
4.2.5 Periodic quality fluctuation error, EQ3
4.3 Sampling and overall variance
4.3.1 Sampling variance
4.3.2 Overall variance
5 Sampling schemes
6 Minimization of bias and unbiased increment mass
6.1 Minimizing bias
6.2 Volume of increment for falling stream samplers to avoid bias
6.3 Volume of increment for manual sampling to avoid bias
7 Precision of sampling and determination of increment variance
7.1 Overall precision
7.2 Primary increment variance
7.3 Preparation and testing variance
8 Number of sub-lots and number of increments per sub-lot
9 Minimum mass of solids in lot and sub-lot samples
9.1 General
9.2 Minimum mass of solids in lot samples
9.3 Minimum mass of solids in sub-lot samples
9.4 Minimum mass of solids in lot and sub-lot samples after size reduction
10 Time-basis sampling
10.1 General
10.2 Sampling interval
10.3 Cutters
10.4 Taking of increments
10.5 Constitution of lot or sub-lot samples
10.6 Division of increments and sub-lot samples
10.7 Division of lot samples
10.8 Number of cuts for division
11 Stratified random sampling within fixed time intervals
12 Mechanical sampling from moving streams
12.1 General
12.2 Design of the sampling system
12.2.1 Safety of operators
12.2.2 Location of sample cutters
12.2.3 Provision for duplicate sampling
12.2.4 System for checking the precision and bias
12.2.5 Minimizing bias
12.3 Slurry sample cutters
12.3.1 General
12.3.2 Falling‑stream cutters
12.3.3 Cutter velocities
12.4 Mass of solids in increments
12.5 Number of primary increments
12.6 Routine checking
13 Manual sampling from moving streams
13.1 General
13.2 Choosing the sampling location
13.3 Sampling implements
13.4 Mass of solids in increments
13.5 Number of primary increments
13.6 Sampling procedures
14 Sampling of stationary slurries
15 Sample preparation procedures
15.1 General
15.2 Reduction mills
15.3 Sample division
15.4 Chemical analysis samples
15.5 Physical test samples
16 Packing and marking of samples
Annex A (informative) Examples of correct slurry devices
Annex B (informative) Examples of incorrect slurry sampling devices
Annex C (normative) Manual sampling implements
Bibliography