ISO 13313:2017 pdf download

ISO 13313:2017 pdf download.Iron ores — Determination of sodium — Flame atomic absorption spectrometric method
1 Scope
This document specifies a flame atomic absorption spectrometric method for the determination of the mass fraction of sodium in iron ores.
This method is applicable to mass fractions of sodium between 0,002 5 % and 0,50 % in natural iron ores, iron ore concentrates and agglomerates, including sinter products.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 2596, Iron ores — Determination of hygroscopic moisture in analytical samples — Gravimetric, Karl Fischer and mass-loss methods
ISO 3082, Iron ores — Sampling and sample preparation procedures
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 7764, Iron ores — Preparation of predried test samples for chemical analysis
ISO 11323, Iron ore and direct reduced iron — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
4 Principle
The test portion is decomposed by treatment with hydrochloric acid and hydrofluoric acid, followed by evaporation to dryness. The residue is wetted and the evaporation repeated with a new portion of hydrochloric acid. The residue is dissolved with hydrochloric acid and appropriately diluted. The solution is aspirated into the air/acetylene flame of the atomic absorption apparatus.
Except where stated, glass equipment should be avoided, as it could contaminate the solutions. The caps of the plastic bottles should be of a type that does not contain a separate wad insert. Such inserts usually contain a sodium compound that will contaminate the solution. To obtain reliable values, the equipment should be cleaned and checked as follows. a) Rinse all volumetric ware, including the pipettes used for preparing the calibration solutions, with dilute hydrochloric acid (5.3) before use. Check calibration regularly or as needed. b) Clean PTFE vessels and stirring bars by stirring with 50 ml of dilute hydrochloric acid (5.3) and heating for 15 min. Reject the rinsings and conduct a blank test in each vessel in turn, exactly as specified in 8.3. If any absorbance value is above the limit specified in 8.3, the cleaning procedure should be repeated or acid reagents of a higher purity should be used. At no stage should the stirring bars be handled with the fingers. c) Platinum vessels, exclusively used for sodium analysis according to this document, can be cleaned by the same method as the PTFE vessels [see b)]. Otherwise, they should be pre-cleaned by fusion with lithium tetraborate or lithium borate, until the absorbance readings fall to those for the lithium salt alone.