ISO 15237:2016

Overview

ISO 15237:2016 sets the international standard for determining the total mercury content in coal, a critical measure in assessing environmental and health impacts of coal use. Developed by ISO/TC 27 (Solid mineral fuels), this method utilizes a precise oxygen bomb combustion procedure followed by atomic absorption spectrometry to quantify mercury accurately. The standard replaces the previous 2003 edition, providing a technically updated protocol to ensure repeatability, reproducibility, and unbiased results in mercury detection within solid mineral fuels.

Key Topics

• Scope and Purpose
  Specifies a reliable analytical procedure for total mercury measurement in coal samples, crucial due to mercury’s volatility and environmental risk during combustion.

• Sample Preparation
  Utilizes test samples prepared in accordance with other ISO standards (e.g., ISO 5069-2, ISO 13909-4) ensuring representative, equilibrium-moisture coal specimens for analysis.

• Oxygen Bomb Combustion
  Coal samples (~1 g) are combusted inside a mercury-free oxygen bomb under controlled oxygen pressure, capturing mercury species produced during combustion in water.

• Reagents and Apparatus
  Requires analytical grade reagents such as stannous chloride solution, potassium permanganate, and hydroxylammonium chloride. Instrumentation involves an atomic absorption spectrometer with flameless cold-vapour mercury detection capabilities.

• Analytical Procedure
  Mercury absorption in water is chemically reduced and quantified via flameless cold vapour atomic absorption spectroscopy. Calibration against matrix-matched mercury standard solutions ensures accuracy.

• Quality Control
  Includes blank determinations and precision metrics like repeatability limits and reproducibility critical differences to guarantee confident mercury quantification.

Applications

ISO 15237:2016 is essential for laboratories and organizations engaged in:

• Environmental Monitoring
  Measuring mercury emission potential in coal-fired power plants to support regulatory compliance and pollution control programs.

• Coal Quality Control
  Enabling coal producers and consumers to assess elemental mercury content, improving health and safety practices in coal handling and utilization.

• Research and Academic Studies
  Providing a standardized baseline method for mercury content determination encouraging data comparability and method validation.

• Industrial Emission Reduction Strategies
  Facilitating the identification of high-mercury coal batches to inform cleaner combustion technologies and mercury emission mitigation.

Related Standards

• ISO 5069-2: Brown coals and lignites - Principles of sampling - Part 2: Sample preparation for determination of moisture content and analysis
  Establishes procedures for preparing representative coal samples integral to ISO 15237 testing accuracy.

• ISO 13909-4: Hard coal and coke - Mechanical sampling - Part 4: Coal - Preparation of test samples
  Defines mechanical sampling methods to ensure uniform coal samples used in mercury content analysis.

• ISO 3696: Water for analytical laboratory use - Specification and test methods
  Specifies high purity water requirements used in reagents and washing during the mercury determination process.

• ISO 1928: Solid mineral fuels - Determination of gross calorific value by bomb calorimeter method
  Describes the oxygen bomb calorimeter apparatus that also serves as a basis for the combustion system in mercury testing.

Accurate determination of mercury content in coal following ISO 15237:2016 aids stakeholders in minimizing environmental mercury release, upholding regulatory frameworks, and promoting sustainable coal utilization. Following this internationally recognized standard ensures reliable, reproducible mercury analysis that underpins effective public health and environmental safeguards.