BS ISO 20904:2020
$167.15
Hard coal. Sampling of slurries
| Published By | Publication Date | Number of Pages |
| BSI | 2020 | 44 |
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.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 7 | Foreword |
| 9 | 1 Scope 2 Normative references 3 Terms and definitions |
| 10 | 4 Principles of sampling slurries 4.1 General |
| 11 | 4.2 Sampling errors 4.2.1 General |
| 12 | 4.2.2 Preparation error 4.2.3 Delimitation and extraction errors |
| 13 | 4.2.4 Weighting error, EW |
| 14 | 4.2.5 Periodic quality fluctuation error, EQ3 4.3 Sampling and overall variance 4.3.1 Sampling variance 4.3.2 Overall variance |
| 15 | 5 Sampling schemes |
| 21 | 6 Minimization of bias and unbiased increment mass 6.1 Minimizing bias |
| 22 | 6.2 Volume of increment for falling stream samplers to avoid bias 6.3 Volume of increment for manual sampling to avoid bias |
| 23 | 7 Precision of sampling and determination of increment variance 7.1 Overall precision 7.2 Primary increment variance |
| 24 | 7.3 Preparation and testing variance 8 Number of sub-lots and number of increments per sub-lot |
| 25 | 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 |
| 26 | 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 |
| 27 | 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 |
| 28 | 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 |
| 29 | 12.3 Slurry sample cutters 12.3.1 General |
| 30 | 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 |
| 31 | 13 Manual sampling from moving streams 13.1 General 13.2 Choosing the sampling location |
| 32 | 13.3 Sampling implements 13.4 Mass of solids in increments 13.5 Number of primary increments 13.6 Sampling procedures |
| 33 | 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 |
| 34 | 16 Packing and marking of samples |
| 35 | Annex A (informative) Examples of correct slurry devices |
| 38 | Annex B (informative) Examples of incorrect slurry sampling devices |
| 42 | Annex C (normative) Manual sampling implements |
| 43 | Bibliography |
