ISO 12985-2:2018

Overview

ISO 12985-2:2018 specifies a standardized hydrostatic method for determining the apparent density and open (to water) porosity of carbonaceous materials, such as baked anodes and cathode blocks used in aluminium production. This international standard, developed by the International Organization for Standardization (ISO), ensures accuracy and consistency in measuring the key quality attributes of these carbonaceous products. It is particularly valuable for analyzing samples with complex or irregular geometries, where traditional drilling or sampling is challenging.

Compliance with ISO 12985-2:2018 promotes uniform assessment practices across the aluminium industry, improving product quality control, material characterization, and process optimization.

Key Topics

• Hydrostatic Method: Utilizes immersion, boiling, and weighing techniques to determine physical properties of carbonaceous materials.
• Apparent Density: Defined as the ratio of the dry mass of the sample to its displaced water volume.
• Open Porosity: Calculated as the fraction of sample volume occupied by open pores accessible to water, determined using the Archimedes principle.
• Sampling: Procedures align with ISO 8007-1 and ISO 8007-2 to ensure representative and repeatable sample selection for cathode blocks and prebaked anodes.
• Testing Precision: The standard specifies clear repeatability and reproducibility criteria, ensuring consistency within and between laboratories.
• Reporting Requirements: Details necessary for test documentation, including sample identification, method references, test conditions, and any deviations.

Applications

• Quality Control in Aluminium Production: Provides critical data for assessing and controlling the properties of baked anodes and cathode blocks, directly impacting the efficiency and reliability of aluminium electrolysis cells.
• Material Characterization: Supports precise measurement of apparent density and porosity, which are essential for predicting the mechanical stability and operational performance of carbon materials.
• Research and Development: Facilitates comparative studies and innovation in carbonaceous material design for enhanced aluminium production processes.
• Supplier Assessment: Assists manufacturers and producers in verifying specifications and ensuring that delivered materials meet industry standards.
• Testing of Irregular Samples: Especially suitable for samples with complex geometries where mechanical drilling is impractical, providing a reliable alternative for challenging material evaluations.

Related Standards

• ISO 8007-1: Carbonaceous materials used in the production of aluminium - Sampling plans and sampling from individual units - Part 1: Cathode blocks.
• ISO 8007-2: Carbonaceous materials used in the production of aluminium - Sampling plans and sampling from individual units - Part 2: Prebaked anodes.
• ISO 5725 series: Accuracy (trueness and precision) of measurement methods and results, offering guidance on repeatability, reproducibility, and measurement method validation.

Adherence to ISO 12985-2:2018 ensures that laboratories, manufacturers, and quality assurance professionals have a reliable, internationally recognized approach to evaluating the density and porosity of carbonaceous materials, essential for the control, optimization, and innovation within the aluminium industry. This enhances communication between suppliers and producers and supports compliance with global trade and quality requirements.