Accurately Determining Sulfur Levels in Ore Concentrate

This article discusses the steps and setting necessary to evaluate the sulfur level in ore concentrates using the CS/S844. The efficiency of the concentration process can be determined using the sulfur level of the ore concentrate as a quality control measure. It can also be used to obtain an estimate of the metal-in-concentrate.

The CS/S844 sulfur by combustion analyzer, equipped with an easy-to-use touch-screen interface and a broad sulfur detection range, can be used in all mining operations laboratories.

Sample Preparation

Prior to analysis, samples must be crushed to a uniform powder form.

Accessories

LECOCEL II (502-173 or 501-008); 528-018 or 528-018HP Crucible; 773-579 Metal Scoop; 502-231 Iron Chip or 501-077 Accelerator; 761-929 Tongs

To obtain optimal sulfur precision, ceramic crucibles can be pre-baked in a tube furnace (LECO TF1/TF-10) at ≥1250°C for a minimum of 15 minutes, or in a muffle oven at ≥1000°C for a minimum of 1 hour. The crucibles are removed from the muffle oven/tube furnace, allowed to cool, and then transferred to a desiccator for storage.

Clean tongs must be used while handling the baked crucibles to avoid contamination.

Calibration

502-085 Zinc Sulfide Reference Material or other appropriate ore concentrate reference materials.

Method Parameters

Procedure

1. Following the instructions in the operator's instruction manual, prepare instrument for operation.

2. Determine the instrument Blank.

1. Login at least three Blank reps.
2. Add one 773-579 Scoop (~0.8 g) Iron Chip and one 773-579 Scoop (~1.2 g) of LECOCEL II.
3. Put the crucible on the furnace pedestal (or suitable autoloader position if applicable), and start analysis.
4. Repeat steps 2b through 2c at least three times.
5. Follow the procedure described in the operator's instruction manual to set the blank.

3. Drift/Calibrate Correct

1. Login at least three standard/drift reps.
2. Weigh ~0.15 g of 502-085 zinc sulfide reference material or other appropriate calibration/drift material into the crucible. Enter the identification and mass of the reference material.

Note: For multi-mass calibration linear, use ~0.05 to ~0.20 g (three reference material reps at every mass) as alternate calibration.

3. Add one 773-579 Scoop (~0.8 g) Iron Chip and one 773-579 Scoop (~1.2 g) of LECOCEL II.
4. Place the crucible on the furnace pedestal (or suitable autoloader position if applicable) and begin analysis.
5. Repeat steps 3b through 3d at least three times for every calibration/drift reference material intended for calibration/drift.
6. Follow the procedure described in the operator's instruction manual to calibrate/drift correct.

4. Sample Analysis

1. Login a sample with suitable number of reps.
2. Weigh ~0.05 to 0.20 g of ore concentrate sample in the crucible. Enter the identification and mass.

Note: 60 mg sulfur is the maximum instrument range.

3. Add one 773-579 Scoop (~0.8 g) Iron Chip and one 773-579 Scoop (~1.2 g) of LECOCEL II.
4. Place the crucible on the furnace pedestal (or suitable autoloader position if applicable), and begin analysis.

Typical Results

This information has been sourced, reviewed and adapted from materials provided by LECO Corporation.

For more information on this source, please visit LECO Corporation.