Detail of GB/T 10322.1-2023

Introduction of GB/T 10322.1-2023

Iron ores — Sampling and sample preparation procedures Warning: This document can involve hazardous materials, operations and equipment, and does not purport to address all the safety issues associated with its use. It is the responsibility of the user of this document to establish appropriate health and safety practices. 1 Scope This document provides 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. This is in order 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 (Method 2). The methods specified in this document 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 can be installed or where manual sampling can 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 documents contain requirements which, through reference in this text, constitute provisions 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 Note: GB/T 10322.2-2000 Iron ores - Experimental methods for evaluation of quality variation (ISO 3084:1998, IDT) ISO 3085 Iron ores - Experimental methods for checking the precision of sampling sample preparation and measurement Note: GB/T 10322.3-2000 Iron ores - Experimental methods for checking the precision of sampling (ISO 3085:1996, IDT) ISO 3086 Iron ores - Experimental methods for checking the bias of sampling Note: GB/T 10322.4-2014 Iron ores - Experimental methods for checking the bias of sampling (ISO 3086:1998, IDT) ISO 3087 Iron ores - Determination of the moisture content of a lot Note: GB/T 10322.5-2016 Iron ores - Determination of the moisture content of a lot (ISO 3087:2011, IDT) ISO 3271 Iron ores for blast furnace and direct reduction feedstocks - Determination of the tumble and abrasion indices Note: GB/T 24531-2009 Iron ores for blast furnace and direct reduction feedstocks - Determination of the tumble and abrasion indices (ISO 3271:2007, IDT) 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 Iron ores for blast furnace and direct reduction feedstocks - Determination of bulk density) Note: GB/T 34568-2017 Iron ores for blast furnace and direct reduction feedstocks - Determination of bulk density (ISO 3852:2007, IDT) ISO 4695 Iron ores for blast furnace feedstocks - Determination of the reducibility by the rate of reduction index Note: GB/T 24515-2009 Iron ores for blast furnace feedstocks - Determination of the reducibility by the rate of reduction index (ISO 4695:2007, IDT) 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 Note: GB/T 31923.1-2015 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 4696-1:2007, MOD) 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 Note: GB/T 31923.2-2015 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction-disintegration indices by static method - Part 2: Reduction with CO and N2 (ISO 4696-2 :2007, MOD) ISO 4698 Iron ore pellets for blast furnace feed- stocks - Determination of the free- swelling index Note: GB/T 13240-2018 Iron ore pellets for blast furnace feedstocks - Determination of the free-swelling index (ISO 4698:2007, MOD) ISO 4700 Iron ore pellets for blast furnace and direct reduction feedstocks - Determination of the crushing strength Note: GB/T 14201-2018 Iron ore pellets for blast furnace and direct reduction feedstocks - Determination of the crushing strength (ISO 4700:2015, MOD) ISO 4701 Iron ores and direct reduced iron - Determination of size distribution by sieving Note: GB/T 10322.7-2016 Iron ores and direct reduced iron - Determination of size distribution by sieving (ISO 4701:2008, IDT) ISO 7215 Iron ores for blast furnace feedstocks - Determination of the reducibility by the final degree of reduction index Note: GB/T 24189-2009 Iron ores for blast furnace feedstocks - Determination of the reducibility by the final degree of reduction index (ISO 7215:2007, IDT) ISO 7992 Iron ores for blast furnace feedstocks Determination of reduction under load) Note: GB/T 24530-2009 Iron ores for blast furnace feedstocks - Determination of reduction under load (ISO 7992:2007, IDT) ISO 8371 Iron ores for blast furnace feedstocks - Determination of the decrepitation index) Note: GB/T 10322.6-2022 Iron ores for blast furnace feedstocks - Determination of the decrepitation index (ISO 8371:2015, IDT) ISO 11256 Iron ore pellets for shaft direct- reduction feedstocks - Determination of the clustering index Note: GB/T 24237-2009 Iron ore pellets for shaft direct-reduction feedstocks - Determination of the clustering index (ISO 11256:2007, IDT) ISO 11257 Iron ores for shaft direct- reduction feedstocks - Determination of the low-temperature reduction - disintegration index and degree of metallization Note: GB/T 24235-2009 Iron ores for shaft direct-reduction feedstocks - Determination of the low temperature reduction-disintegration index and degree of metallization (ISO 11257:2007, IDT) ISO 11258 Iron ores for shaft direct- reduction feedstocks - Determination of the reducibility index, final degree of reduction and degree of metallization Note: GB/T 24236-2009 Iron ores for shaft direct-reduction feedstocks - Determination of the low temperature reduction-disintegration index and degree of metallization (ISO 11258:2007, IDT) ISO 11323 Iron ore and direct reduced iron - Vocabulary Note: GB/T 20565-2022 Iron ores and direct reduced iron - Vocabulary (ISO 11323:2010, IDT) ISO 13930 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction- disintegration indices by dynamic method) Note: GB/T 24204-2009 Iron ores for blast furnace feedstocks - Determination of low-temperature reduction-disintegration indices by dynamic method (ISO 13930:2007, IDT) 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11323 and the following apply. 3.1 lot discrete and defined quantity of iron ore or direct reduced iron for which quality characteristics are to be assessed 3.2 increment quantity of iron ore or 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 or 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 from an increment, a partial sample or a gross sample 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 Note: Examples of strata include production periods (e.g. 5 min), production masses (e.g. 1000t), holds in vessels, wagons in a train, or containers and trucks representing a lot. 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 Note 1: This method is required for sampling on a mass basis. Note 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 or R40/3 series in ISO 565), such that no more than 5% by mass of iron ore is retained on the sieve 4 General considerations for sampling and sample preparation 4.1 Basic requirements The basic requirement for a correct sampling scheme is that all parts of the ore in the lot have an equal opportunity of being selected and becoming part of the sample for analysis. Any deviation from this basic requirement can result in an unacceptable loss of trueness and precision. An incorrect sampling scheme cannot be relied on to provide representative samples. The best sampling location to satisfy the above requirement is at a transfer point between conveyor belts. Here the full cross-section of the ore stream can be conveniently intercepted at regular intervals, enabling representative samples to be obtained. Sampling from the top of a moving conveyor belt using cross-belt (hammer) samplers is not permitted, because it is impossible to extract a complete cross-section of the ore stream. Consequently, all parts of the lot do not have an equal opportunity of being sampled. All attempts to validate hammer samplers show significant bias compared to falling-stream and stopped-belt sampling. In situ sampling of ships, stockpiles, containers and bunkers is not permitted, because it is impossible to drive the sampling device down to the bottom and extract the full column of ore. Consequently, all parts of the lot do not have an equal opportunity of being sampled. The only effective procedure is sampling from a transfer point at the end of or between conveyor belts when ore is being conveyed to or from the ship, stockpile, container or bunker. In situ sampling from stationary situations such as trucks or wagons is permitted only for ores with nominal top size less than 1mm, provided the sampling device, e.g. a spear or an auger, penetrates to the full depth of the concentrate at the point selected for sampling and the full column of concentrate is extracted. Sampling shall be carried out by systematic sampling either on a mass basis (see 6.1) or on a time basis (see 6.2), provided no bias is introduced by periodic variations in quality or quantity. However, if periodic variations that could introduce bias are present, stratified random sampling within fixed mass or time intervals shall be carried out (see 6.3). The methods used for sampling and sample preparation depend on the final choice of the sampling scheme and on the steps necessary to minimize possible biases and obtain acceptable overall precision. Moisture samples shall be processed as soon as possible and test portions weighed immediately. If this is not possible, samples shall be stored in non-absorbent airtight containers with a minimum of free air space to minimize any change in moisture content, but should be prepared without delay. 4.2 Establishing a sampling scheme The procedure for establishing a sampling scheme is as follows: a) identify the lot to be sampled and the quality characteristics to be determined; b) ascertain the nominal top size; c) determine the sampling location and the method of taking increments; d) determine the mass of increment considering the nominal top size, the ore-handling equipment and the device for taking increments; e) specify the precision required; f) ascertain the quality variation, σW, of the lot in accordance with ISO 3084, or, if this is not possible, assume “large” quality variation as specified in 5.3; g) determine the minimum number of primary increments, n1, to be taken from the lot for systematic or stratified random sampling; h) determine the sampling interval in tonnes for mass-basis sampling or in minutes for time-basis sampling; i) take increments having almost uniform mass for mass-basis sampling or having a mass proportional to the flow rate of the ore stream at the time of sampling for time-basis sampling. Increments are to be taken at the intervals determined in (h) during the entire period of handling the lot; j) determine whether the sample is for split use or multiple use; k) establish the method of combining increments into a gross sample or partial samples; l) establish the sample preparation procedure, including division, crushing, mixing and drying; m) crush the sample, if necessary, except for the size sample and some physical testing samples; n) dry the sample, if necessary, except for the moisture sample; o) divide samples according to the minimum mass of divided sample for a given nominal top size, employing constant mass or proportional division for mass-basis sampling, or proportional division for time-basis sampling; p) prepare the test sample. Special attention shall be given to the total mass of test sample required for physical tests (see 10.1.6.3). When the mass of the gross sample or partial samples is expected to be less than that required for preparation of test samples for physical testing, the number and/or mass of increments to be taken shall be increased to give the required mass. It is preferable that the number of increments be increased, rather than the increment mass. 4.3 System verification Stopped-belt sampling is the reference method for collecting samples against which mechanical and manual sampling procedures may be compared to establish that they are unbiased in accordance with procedures specified in ISO 3086. However, before any bias tests are conducted, sampling and sample preparation systems shall first be inspected to confirm that they conform to the correct design principles specified in this document. Inspections shall also include an examination of whether any loading, unloading or reclaiming procedures could produce periodic variations in quality in phase with the taking of increments. These periodic variations could include characteristics such as particle size distribution and moisture content. When such cyclic variations occur, the source of the variations shall be investigated to determine the practicability of eliminating the variations. If this is not possible, stratified random sampling shall be carried out (see 6.3). An example of a suitable inspection procedure and checklist is provided in Annex A. This will quickly reveal any serious deficiencies in the sampling or sample preparation system and may avoid the need for expensive bias testing. Consequently, sampling systems shall be designed and constructed in a manner that facilitates regular verification of correct operation. Note: Further details can be found in ISO/TC 102 Technical Committee Report No. 14, Iron ores and direct reduced iron — Guide to the inspection of mechanical sampling systems. Regular checks of quality variation and precision shall also be carried out in accordance with ISO 3084 and ISO 3085 to monitor variations in quality variation and to verify the precision of sampling, sample preparation and measurement. This is particularly important for new products or new sampling systems or when significant changes are made to existing systems.

Contents of GB/T 10322.1-2023

Foreword IV Introduction VI 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 5.1.2 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 General 6.3.2 Fixed mass intervals 6.3.3 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 Online 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 trucks and wagons 8.2.1 General 8.2.2 Sampling devices 8.2.3 Number of primary increments 8.2.4 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 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 method 10.4.3 Manual strip-division method 10.4.4 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 nominal top size 10.5.3 Final preparation 10.5.4 Grinding to 100µm or 160µm nominal top size 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) Formulae 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