Iron content of Iron ores— Potentiometric Titration Method

The REX Ti-50 Automatic Potential Titrator allows quick and simple determinations of the iron content of iron ores by potentiometric titration.

1. Standard Reference

ISO/TS 2597-4-2019《Iron ores-Determination of iron content -Part 4： Potentiometric titration method》

This document specifies a potentiometric titration method for the determination of total iron content of iron ores, using potassium dichromate as titrant after reduction of the iron(III) by tin(II) chloride and titanium(III) chloride. The excess reductant is then oxidized by potassium dichromate solution. This method is applicable to total iron contents between a mass fraction of 29,04 % and a mass fraction of 72,02 % in natural iron ores and iron ore concentrates and agglomerates including sinter products.

 

2. The Principle

For samples containing not more than a mass fraction of 0,1 % of vanadium, copper or manganese, the test portion is treated with hydrochloric acid in the presence of tin chloride and the residue is filtered, ignited and treated with hydrofluoric and sulfuric acids. The mixture is fused with potassium disulfate and the cold melt is dissolved in water and hydrochloric acid and neutralized with ammonia solution. The precipitate is filtered, washed with water, dissolved with hydrochloric acid and combined with the main iron solution, which is treated with potassium permanganate and evaporated. Finally, after the combined solution is treated with correlative reagents, the total iron in solution is titrated by a potentiometric titrator.

3. Recommended Configuration

 

1. Ti-50 Automatic Potential Titrator 

• Range：(-2000.00~2000.00) mV
• mV Accuracy：±0.03% or ±0.2mV
• 1 extra burette driver can be installed (optional).
• Replaceable burette with high-accuracy (10 ml or 20 ml selectable).
• Support acid-base titration, non-aqueous aqueous phase titration, constant titration, REDOX titration, precipitation titration, complexation titration
• Support the following titration modes: DET (dynamic equivalence point titration), MET (monotone equivalence point titration), SET (Preset Endpoint Titration) and MAT (manual titration).
• Titration methods, curves and results are displayed in detail.
• Includes 213-01 platinum electrode and 232-01 reference electrode.

1. Auxiliary titration unit 20mL
2. Burette valve device 20mL (SC5.461.057)
3. Anti-diffusion capillary
4. Electrodes

• 213-01 Platinum electrode
• 232-01 Reference electrode（Saturated KCl）

Model	213-01
Name	Platinum electrode
Connector Type	BNC(Q9)
Sensor material	Glass
Dimensions	Φ12×120mm
Measuring unit material	Platinum
Working Temperature	5~50 ℃
Application	REDOX Titration

Model	232-01
Name	Reference electrode
Type of electrode	Saturated single-junction calomel electrode
Connector Type	U shape terminal
Fill Solution	Saturated KCl solution
junction material	ceramic
Sensor material	Glass
Dimensions	Φ12×120 mm
Working Temperature	5~55 ℃

 

4. Titration Setting

• REDOX titration
• Sample: DET (dynamic equivalence point titration)
• Blank Sample: MET (monotone equivalence point titration)

 

5. Titration curve

 

 

The titration curve of the total content of iron