ISO 21557:2025

Overview

ISO 21557:2025 - Mining - Mining methods - Classification and specification (First edition, 2025) defines a uniform framework for classifying mining methods. The standard helps practitioners select and specify surface and underground mining methods by linking method choice to measurable specifications such as ore grade and recovery, infrastructure and extraction costs, labour and machine costs, underground support costs, and geotechnical factors. ISO 21557 promotes comparability and consistency of mining information across feasibility studies, design phases and regulatory submissions.

Key topics and technical requirements

• Scope and purpose
  • Establishes a classification system for mining methods to guide preliminary selection and mine design decisions.
• Two primary categories
  • Surface mining (including open pit, quarrying, strip and auger methods).
  • Underground mining (grouped by rock competency and cavability).
• Specification criteria used for classification
  • Ore grade and recoveries
  • Costing elements: infrastructure, extraction, labour, machinery
  • Underground support requirements
  • Geotechnical and ground-control factors
• Surface mining considerations
  • Evaluation factors: geography, land/legal status, socio-political factors, geology, mining conditions, ore treatment and economic analysis.
  • Typical sequence of operations: overburden stripping, drilling (probe, grade control, production), charging, blasting, mucking and reclamation.
  • Detailed description of open-pit workflows (layout, probe drilling, grade control, production drilling, charging, blasting, clearing and excavation).
• Normative references and terminology
  • Uses ISO 22932 series for mining vocabulary and terms to ensure consistent definitions.

Practical applications and users

ISO 21557 is intended for use in:

• Mining engineers and mine planners - for preliminary method selection and layout inputs.
• Geotechnical engineers and geologists - to relate ground conditions and ore properties to suitable mining methods.
• Feasibility and economic analysts - to structure cost and recovery assumptions tied to method classification.
• Environmental & regulatory authorities - for reviewing proposed mining method suitability and impacts.
• Consultants and investors - to compare project proposals using a common classification framework.

Practical uses include initial method screening, feed to detailed mine design, safety and ground-control planning, and standardizing technical reports for comparability.

Related standards

• ISO 22932 (Mining - Vocabulary) - normative reference for terms and definitions used in ISO 21557.
• Prepared by ISO/TC 82 (Mining) - consult your national standards body for implementation guidance.

Keywords: ISO 21557:2025, mining methods classification, surface mining, underground mining, ore grade, geotechnical factors, mine design, mining standards.