Copper sulfate pentahydrate and sodium hydrosulfide are two inorganic workhorses of mineral flotation with opposite jobs: copper sulfate activates zinc minerals so they can be floated, while sodium hydrosulfide depresses copper minerals so molybdenum can be recovered. Understanding both reagents lets concentrators control their circuits precisely.
Copper Sulfate Pentahydrate: The Zinc Activator
Copper sulfate pentahydrate (CuSO4 . 5H2O, molecular mass 249.7) is a blue-green or blue crystal, easily soluble in water. It conforms to standard HG/T 5215-2017 with copper sulfate content of at least 98.0% (Superior Grade), acidity below 0.1% and water insolubles below 0.2%. See the copper sulfate pentahydrate product page.
How it works: sphalerite (zinc sulfide) does not respond to xanthate collectors unless activated. Copper ions from copper sulfate exchange with zinc ions on the mineral surface, forming a copper sulfide film that xanthate can collect. Typical dosage is 100-1000 g/t in the zinc circuit, added before the collector.
Beyond flotation, copper sulfate is used as a textile mordant, agricultural bactericide and in copper electroplating – a useful co-product for diversified buyers.
Sodium Hydrosulfide: The Copper Depressant
Sodium hydrosulfide (NaHS, molecular mass 56.06) is supplied as a light brown-yellow liquid, conforming to GB/T 23937-2020 with NaHS content of 32.0% or 38.0% and sodium sulfite below 1.0%. See the sodium hydrosulfide product page.
How it works: in copper-molybdenum separation, NaHS adds sulfide ions that coat copper mineral surfaces, preventing collector adsorption and allowing molybdenite to float selectively. It is also used to sulfidize oxidized copper ores before xanthate collection, and in pulp pH control. NaHS is toxic and must be handled with care – dosing systems require sealed storage and ventilation.
Handling and Safety
- Copper sulfate: store dry; solutions are corrosive to some metals; use PPE for handling.
- Sodium hydrosulfide: toxic, corrosive, releases hydrogen sulfide gas in acid conditions; always use closed dosing systems and trained personnel.
Source Both From One Manufacturer
Shanghai Minglan Chemical supplies flotation reagents including copper sulfate pentahydrate, sodium hydrosulfide, sodium sulfide, zinc sulfate and sodium sulfite – the full regulator suite for copper, lead-zinc and molybdenum circuits. Contact info@minglanchem.com for specifications and pricing.
