ISO 9292:1988

Overview

ISO 9292:1988 specifies the 1,10-phenanthroline spectrometric method for determining the total iron content in manganese ores and concentrates. This internationally recognized standard is applicable to products with total iron contents ranging from 0.1% to 15% by mass. It provides detailed instructions on the chemical reactions, reagents, apparatus, sampling, and procedure necessary for accurate and reproducible iron analysis. The standard should be read in conjunction with ISO 4297, which outlines general chemical analysis methods for manganese ores.

Key Topics

• Scope and Application
  The method targets manganese ores and concentrates, applicable for iron determination within a concentration scope of 0.1% to 15% (m/m). It is suited for laboratory settings requiring precise iron analysis according to international norms.

• Analytical Principle
  The core of the method is the formation of a coloured complex of ferrous iron (Fe(II)) with 1,10-phenanthroline under slightly acidic conditions (pH 4 to 5). Ferric iron (Fe(III)) present in the sample is first chemically reduced by hydroxylammonium chloride to Fe(II). The resulting Fe(II)-phenanthroline complex exhibits maximum absorbance between 508 nm and 512 nm, enabling spectrometric measurement.

• Reagents and Apparatus
  Essential reagents include hydrochloric acid, sulfuric acid, hydrofluoric acid, potassium pyrosulfate, hydroxylammonium chloride solution, buffer solutions, and 1,10-phenanthroline solution. Equipment includes common laboratory glassware, platinum or platinum-alloy crucibles for sample preparation, and a spectrophotometer or photoelectrocolorimeter capable of absorbance measurements within the required wavelengths.

• Sample Preparation and Analysis Procedure
  The method details steps for sample dissolution, residue treatment, and complex formation. It emphasizes precise aliquoting, use of blank tests, and calibration curve preparation with standard iron solutions to ensure accuracy. The standard also specifies sample granularity (below 100 µm) and references ISO 4296 parts 1 and 2 for sampling and sample preparation.

• Calculation and Expression of Results
  Iron content is calculated by correlating absorbance values against a calibration curve, corrected for blanks. The results are expressed as percentage mass of total iron, with clearly defined formulas and correction factors to convert measured values to dry basis iron content. Tolerances for repeatability and reproducibility of parallel determinations are provided to assure quality control.

Applications

• Quality Control in Mining and Metallurgy
  ISO 9292:1988 assists mining companies and metallurgical laboratories in accurately assessing iron impurities in manganese ores and concentrates, crucial for processing and refining.

• Export and Trade Compliance
  The standard supports consistent iron content evaluation, facilitating international trade by providing a common analytical method recognized worldwide.

• Research and Development
  Laboratories performing mineralogical studies and developing beneficiation techniques use this standard to quantify iron distribution in manganese-bearing materials.

• Environmental Monitoring and Regulatory Testing
  Environmental labs analyzing ore deposits for regulatory compliance benefit from this standardized approach for iron quantification.

Related Standards

• ISO 4297:1978 – General instructions for chemical analysis of manganese ores and concentrates; complements ISO 9292 by outlining broader chemical analytical procedures.

• ISO 4296-1:1984 & ISO 4296-2:1983 – Cover sampling by increments and sample preparation for manganese ores, essential for preparing representative samples analyzed under ISO 9292.

• ISO 5438 – May include additional related mineral analysis techniques and sampling standards in mining contexts.

Keywords

Manganese ores, manganese concentrates, total iron content, iron determination, 1,10-phenanthroline method, spectrometric analysis, chemical assay, ISO 9292, iron analysis standard, metallurgical testing, ore quality, spectrophotometry, laboratory analysis, industrial minerals.