BS ISO 21283:2018 pdf download.Iron ores — Determination of specific surface area — Test method using air-permeability apparatus (Blaine)
1 Scope
This document specifies a method to determine the fineness of iron ores in terms of specific surface area, using the manual Blaine air-permeability apparatus.
This document is applicable to pellet feeds in the range of 400 cm 2 /g to 2 500 cm 2 /g of specific surface area.
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 3082, Iron ores — Sampling and sample preparation procedures
ISO 11323, Iron ore and direct reduced iron — Vocabulary
ISO 12154, Determination of density by volumetric displacement — Skeleton density by gas pycnometry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 and the following 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 https://www.iso.org/obp
3.1 Blaine surface area
BSA
whole area of surface of pellet feed particles per mass unit
Note 1 to entry: Generally expressed as cm 2 /g.
3.2 pellet feed
iron ore fines traded for pellet production
Note 1 to entry: Usually containing at least 80 % under 0,150 mm.
5 Sampling, sample preparation and preparation of test portions
5.1 Sampling and sample preparation Sampling of a lot and preparation of a test sample shall be in accordance with ISO 3082. A test sample of at least 300 g, on a dry basis, of the material shall be obtained.
5.2 Preparation of test portions Oven-dry the test sample to constant mass at 105 °C ± 5 °C. Cool it to room temperature. NOTE 1 Constant mass is achieved when the difference in mass between two subsequent measurements becomes less than 0,05 % of the initial mass of the test sample. Disaggregate the whole test sample by sieving it on a 1,0 mm sieve or the nearest aperture. Obtain about 50 g of the minus 1,0 mm material. This is the partial test sample. Disaggregate it on a 0,150 mm sieve. Mix and homogenize the material retained and passing on the 0,150 mm sieve. NOTE 2 Manual methods of division recommended in ISO 3082, such as riffling, can be applied to obtain the test portions. The mass of each test portion shall be calculated in accordance with 7.2.1. At least four test portions shall be obtained from the partial test sample. Take several increments using a non-magnetic spatula and weigh to the nearest 0,01 g.