1 Scope
This part of GB/T 10322 gives
a) the underlying theory,
b) the basic principles for sampling and preparation of samples, and
c) the basic requirements for the design, installation and operation of sampling systems
for mechanical sampling, manual sampling and preparation of samples taken from a lot under transfer, to determine the chemical composition, moisture content, size distribution and other physical and metallurgical properties of the lot, except bulk density obtained using ISO 3852:2007 (Method 2).
The methods specified in this part are applicable to both the loading and discharging of a lot by means of belt conveyors and other ore-handling equipment to which a mechanical sampler may be installed or where manual sampling may safely be conducted.
The methods are applicable to all iron ores, whether natural or processed (e.g. concentrates and agglomerates, such as pellets or sinters).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 565 Test sieves - Metal wire cloth, perforated metal plate and electroformed sheet - Nominal sizes of openings
ISO 3084 Iron ores - Experimental methods for evaluation of quality variation
ISO 3085: 2002 Iron ores - Experimental methods for checking the precision of sampling, sample preparation and measurement
ISO 3086 Iron ores - Experimental methods for checking the bias of sampling
ISO 3087 Iron ores - Determination of the moisture content of a lot
ISO 3271 Iron ores for blast furnace and direct reduction feedstocks - Determination of the tumble and abrasion indices
ISO 3310-1 Test sieves - Technical requirements and testing - Part 1: Test sieves of metal wire cloth
ISO 3310-2 Test sieves - Technical requirements and testing - Part 2: Test sieves of perforated metal plate
ISO 3852: 2007 Iron ores for blast furnace and direct reduction feedstocks - Determination of bulk density
ISO 4695 Iron ores for blast furnace feedstocks - Determination of the reducibility by the rate of reduction index
ISO 4696-1 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction-disintegration indices by static method - Part 1: Reduction with CO, CO2, H2 and N2
ISO 4696-2 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction-disintegration indices by static method - Part 2: Reduction with CO and N2
ISO 4698 Iron ore pellets for blast furnace feedstocks - Determination of the free-swelling index
ISO 4700 Iron ore pellets for blast furnace and direct reduction feedstocks - Determination of the crushing strength
ISO 4701 Iron ores and direct reduced iron - Determination of size distribution by sieving
ISO 7215 Iron ores for blast furnace feedstocks - Determination of the reducibility by the final degree of reduction index
ISO 7992 Iron ores for blast furnace feedstocks - Determination of reduction under load
ISO 8371 Iron ores for blast furnace feedstocks - Determination of the decrepitation index
ISO 11256 Iron ore pellets for shaft direct-reduction feedstocks - Determination of the clustering index
ISO 11257 Iron ores for shaft direct-reduction feedstocks - Determination of the low-temperature reduction-disintegration index and degree of metallization
ISO 11258 Iron ores for shaft direct-reduction feedstocks - Determination of the reducibility index, final degree of reduction and degree of metallization
ISO 11323 Iron ore and direct reduced iron - Vocabulary
ISO 13930 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction-disintegration indices by dynamic method
3 Terms and definitions
For the purposes of this document, the terms and definitions contained in ISO 11323, as well as those given below, apply.
3.1
lot
discrete and defined quantity of iron ore and direct reduced iron for which quality characteristics are to be assessed
3.2
increment
quantity of iron ore and direct reduced iron collected in a single operation of a device for sampling or sample division
3.3
sample
relatively small quantity of iron ore and direct reduced iron, so taken from a lot as to be representative in respect of the quality characteristics to be assessed
3.4
partial sample
sample comprising of less than the complete number of increments needed for a gross sample
3.5
gross sample
sample comprising all increments, entirely representative of all quality characteristics of a lot
3.6
test sample
sample prepared to meet all specific conditions for a test
3.7
test portion
part of a test sample that is actually and entirely subjected to the specific test
3.8
stratified sampling
sampling of a lot carried out by taking increments from systematically specified positions and in appropriate proportions from strata
3.9
systematic sampling
sampling carried out by taking increments from a lot at regular intervals
3.10
mass-basis sampling
sampling carried out so that increments are taken at equal mass intervals, increments being as near as possible of uniform mass
3.11
time-basis sampling
sampling carried out so that increments are taken from free falling streams, or from conveyors, at uniform time intervals, the mass of each increment being proportional to the mass flow rate at the instant of taking the increment
3.12
proportional mass division
division of samples or increments such that the mass of each retained divided portion is a fixed proportion of the mass being divided
3.13
constant mass division
division of samples or increments such that the retained divided portions are of almost uniform mass, irrespective of variations in mass of the samples or increments being divided
Notes:
1 This method is required for sampling on a mass basis.
2 “Almost uniform” means that variations in mass are less than 20 % in terms of the coefficient of variation.
3.14
split use of sample
separate use of parts of a sample, as test samples for separate determinations of quality characteristics
3.15
multiple use of sample
use of a sample in its entirety for the determination of one quality characteristic, followed by the use of the same sample in its entirety for the determination of one or more other quality characteristics
3.16
nominal top size
particle size expressed by the smallest aperture size of the test sieve (from a square opening complying with the R20 series in ISO 565), such that no more than 5 % by mass of iron ore is retained on the sieve
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General considerations for sampling and sample preparation
4.1 Basic requirements
4.2 Establishing a sampling scheme
4.3 System verification
5 Fundamentals of sampling and sample preparation
5.1 Minimization of bias
5.1.1 General
5.1.2 Minimization of particle size degradation
5.1.3 Extraction of increments
5.1.4 Increment mass
5.2 Overall precision
5.3 Quality variation
5.4 Sampling precision and number of primary increments
5.4.1 Mass-basis sampling
5.4.2 Time-basis sampling
5.5 Precision of sample preparation and overall precision
5.5.1 General
5.5.2 Preparation and measurement of gross sample
5.5.3 Preparation and measurement of partial samples
5.5.4 Preparation and measurement of each increment
6 Methods of sampling
6.1 Mass-basis sampling
6.1.1 Mass of increment
6.1.2 Quality variation
6.1.3 Number of primary increments
6.1.4 Sampling interval
6.1.5 Methods of taking increments
6.2 Time-basis sampling
6.2.1 Mass of increment
6.2.2 Quality variation
6.2.3 Number of increments
6.2.4 Sampling interval
6.2.5 Methods of taking increments
6.3 Stratified random sampling within fixed mass or time intervals
6.3.1 Fixed mass intervals
6.3.2 Fixed time intervals
7 Sampling from moving streams
7.1 General
7.2 Safety of operations
7.3 Robustness of sampling installation
7.4 Versatility of sampling system
7.5 Primary samplers
7.5.1 Location
7.5.2 Types of primary sampler
7.5.3 General design criteria for primary cutters
7.5.4 Cutter aperture of primary sampler
7.5.5 Cutter speed of primary sampler
7.6 Secondary and subsequent samplers
7.7 On-line sample preparation
7.7.1 Arrangement for sample preparation
7.7.2 Crushers
7.7.3 Dividers
7.7.4 Dryers
7.8 Checking precision and bias
7.9 Cleaning and maintenance
7.10 Example of a flowsheet
8 Sampling from stationary situations
8.1 General
8.2 Sampling from wagons
8.2.1 Sampling devices
8.2.2 Number of primary increments
8.2.3 Method of sampling
8.3 Sampling from ships, stockpiles and bunkers
9 Stopped-belt reference sampling
10 Sample preparation
10.1 Fundamentals
10.1.1 General
10.1.2 Drying
10.1.3 Crushing and grinding
10.1.4 Mixing
10.1.5 Sample division
10.1.6 Mass of divided sample
10.1.7 Split use and multiple use of sample
10.2 Method of constituting partial samples or a gross sample
10.2.1 General
10.2.2 Method of constitution for mass-basis sampling
10.2.3 Method of constitution for time-basis sampling
10.2.4 Special procedure for moisture content
10.3 Mechanical methods of division
10.3.1 Mechanical increment division
10.3.2 Other mechanical division methods
10.4 Manual methods of division
10.4.1 General
10.4.2 Manual increment division
10.4.3 Manual riffle-division method
10.5 Preparation of test samples for chemical analysis
10.5.1 Mass and particle size
10.5.2 Preparation to -250 μm
10.5.3 Final preparation
10.5.4 Grinding to -100 µm or -160 µm
10.5.5 Distribution of samples for chemical analysis
10.6 Preparation of test samples for moisture determination
10.7 Preparation of test samples for size determination
10.8 Preparation of test samples for physical testing
10.8.1 Selection of sample preparation procedure
10.8.2 Extraction of test samples
10.8.3 Reserve samples
11 Packing and marking of samples
Annex A (Informative) Inspection of mechanical sampling systems
Annex B (Normative) Equation for number of increments
Annex C (Informative) Alternative methods of taking the reference sample
Annex D (Normative) Procedure for determining the minimum mass of divided gross sample for size determination using other mechanical division methods
Annex E (Normative) Riffle dividers
Bibliography
