ISO 12988-1:2000

Overview

ISO 12988-1:2000 - Carbonaceous materials used in the production of aluminium - Part 1: Loss in mass method - specifies a laboratory procedure to determine the reactivity of baked anodes to carbon dioxide (CO2). The method was developed for baked anodes used in aluminium electrolysis and quantifies how much anode material reacts with CO2 under controlled high-temperature conditions.

Key topics and requirements

• Scope: Measures reactivity-to-CO2 for carbonaceous products (baked anodes) using a loss-in-mass test.
• Test conditions: Specimens (two cores per test) are heated at 960 ±2 °C in a furnace purged with CO2 for 7 hours, with a controlled CO2 flow of 200 L/h.
• Specimen preparation: Cores of 50 ±1 mm diameter × 60 ±1 mm length, dried at 120 ±5 °C for 12 h. Initial and post-test masses are recorded to 0.1 g.
• Atmosphere purity: CO2 gas minimum 99.5% by volume (impurities N2/Ar ≤ 0.5% vol.; H2O ≤ 150 mg/m3).
• Apparatus & controls: Vertical muffle furnace (≥1000 °C capability), K-type thermocouple (IEC 60584-2 reference), gas-flow meter/manometer (pressure ~0.2 MPa), alumina preheater tube, and a tumbling apparatus (two chambers, steel balls, 4 mm sieve) to separate dust from unreacted residue.
• Measurements & results: Compute mass-percent residue, dust and loss using specified formulae; report results in mass percent and to 0.1 g. Repeatability depends on core homogeneity; reproducibility estimates are provided based on multi-lab studies.
• Sampling reference: When extracting cores from larger anodes follow ISO 8007-2.

Applications and users

This standard is practical for:

• Anode manufacturers - quality control and product specification (CO2 reactivity performance).
• Aluminium producers & smelters - evaluating anode behaviour in electrolytic cells and predicting material loss and dust generation.
• Materials R&D - testing formulations and baking processes to optimize resistance to CO2 attack.
• Third‑party testing laboratories - standardized method for contract testing and compliance checks.
• Procurement/specification writers - establishing acceptance criteria in supply contracts.

Practical benefits include consistent, comparable reactivity data for lifetime prediction, process optimization, and supplier qualification.

Related standards

• ISO 8007-2 - Sampling plans and sampling from individual units (prebaked anodes) - referenced for specimen extraction.
• IEC 60584-2 - Thermocouples - tolerances - referenced for K-type thermocouple accuracy.
• Note: ISO 12988 Part 2 (thermogravimetric method) is indicated as a future complement to this loss-in-mass method.

Keywords: ISO 12988-1:2000, baked anodes, reactivity to carbon dioxide, loss in mass method, carbonaceous materials, aluminium production, CO2 reactivity test.