ISO 11794:2017

INTERNATIONAL ISO
STANDARD 11794
Second edition
2017-06
Copper, lead, zinc and nickel
concentrates — Sampling of slurries
Concentrés de cuivre, de plomb, de zinc et de nickel —
Échantillonnage des schlamms
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principles of sampling slurries . 2
4.1 General . 2
4.2 Sampling errors . 3
4.2.1 General. 3
4.2.2 Preparation error, PE . 4
4.2.3 Delimitation and extraction errors, DE and EE . 4
4.2.4 Weighting error, WE . 6
4.2.5 Periodic quality-fluctuation error, QE .
3 6
4.3 Sampling and total variance . 6
4.3.1 Sampling variance. 6
4.3.2 Total variance . 6
4.3.3 Sampling-stage method of estimating sampling and total variance . 8
4.3.4 Simplified method of estimating sampling and total variance . 9
4.3.5 Interleaved sample method of measuring total variance .10
5 Establishing a sampling scheme .11
6 Minimization of bias and unbiased increment mass .16
6.1 Minimization of bias .16
6.2 Volume of increment for falling-stream samplers to avoid bias.17
7 Number of increments .17
7.1 General .17
7.2 Simplified method .18
8 Minimum mass of solids contained in lot and sub-lot samples .18
8.1 Minimum mass of solids in lot samples .18
8.2 Minimum mass of solids in sub-lot samples .18
8.3 Minimum mass of solids in lot and sub-lot samples after size reduction .18
9 Time-basis sampling .19
9.1 General .19
9.2 Sampling interval .19
9.3 Cutters .19
9.4 Taking of increments .19
9.5 Constitution of lot or sub-lot samples .19
9.6 Division of increments and sub-lot samples .20
9.7 Division of lot samples .20
9.8 Number of cuts for division .20
10 Stratified random sampling within fixed time intervals.20
11 Mechanical sampling from moving streams .21
11.1 General .21
11.2 Design of the sampling system .21
11.2.1 Safety of operators .21
11.2.2 Location of sample cutters .21
11.2.3 Provision for duplicate sampling .21
11.2.4 System for checking the precision and bias.21
11.2.5 Avoiding bias .21
11.3 Slurry sample cutters .22
11.3.1 General.22
11.3.2 Falling-stream cutters .22
11.3.3 Cutter velocities .23
11.4 Mass of solids in increments .23
11.5 Number of primary increments .23
11.6 Routine checking .23
12 Manual sampling from moving streams .23
12.1 General .23
12.2 Choosing the sampling location .24
12.3 Sampling implements .24
12.4 Mass of solids in increments .25
12.5 Number of primary increments .25
12.6 Sampling procedures .25
13 Sampling of stationary slurries .25
14 Sample preparation .25
14.1 General .25
14.2 Sample division.25
14.3 Sample grinding .26
14.4 Chemical analysis samples . .26
14.5 Physical test samples .26
15 Packing and marking of samples .26
Annex A (normative) Sampling-stage method for estimating sampling and total variance .27
Annex B (informative) Examples of correct slurry sampling devices .34
Annex C (informative) Examples of incorrect slurry sampling devices .37
Annex D (normative) Manual sampling implements .41
Bibliography .42
iv © ISO 2017 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO tec
...