Influence of SHMP Concentration on Rutile Flotation in BHA System: Guiding the Separation of Rutile and Hornblende

Area of Science:

• Mineral Processing
• Surface Chemistry
• Materials Science

Background:

• Sodium hexametaphosphate (SHMP) is a widely used depressant in rutile flotation, particularly for silicate gangue minerals.
• SHMP's interaction with rutile in the presence of benzyl hydroxamic acid (BHA) is complex and concentration-dependent.
• Understanding SHMP's influence is crucial for optimizing rutile flotation efficiency.

Purpose of the Study:

• To investigate the mechanism by which SHMP concentration affects rutile flotation in a BHA system.
• To determine the optimal concentration of SHMP for rutile flotation with BHA.

Main Methods:

• Flotation tests were conducted to evaluate recovery rates.
• Adsorption capacity, zeta potential, infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to analyze surface interactions.

Main Results:

• SHMP chemically adsorbs onto the rutile surface, interfering with BHA adsorption and reducing flotation recovery.
• The most significant effect of SHMP was observed at a BHA concentration of 40 mg/L and SHMP concentration of 6 mg/L.
• At SHMP concentrations of 8-10 mg/L, its inhibitory effect on rutile flotation weakened considerably.

Conclusions:

• At low SHMP concentrations (<6 mg/L), SHMP anions interact with hydrophilic colloids on the rutile surface, blocking BHA active sites.
• Increased SHMP concentration leads to desorption from the rutile surface due to charge repulsion and competitive adsorption with BHA.
• The study elucidates the concentration-dependent mechanism of SHMP as a depressant in BHA-based rutile flotation.