Flotation separation of scheelite and calcite using the biopolymer konjac glucomannan: A novel and eco-friendly depressant

• Konjac glucomannan (KGM) acts as a highly selective depressant for calcite in scheelite flotation, achieving a recovery difference of 82.53% at 50 mg/L. • KGM selectively adsorbs on calcite surfaces via chemical interactions, blocking sodium oleate adsorption and enhancing separation efficiency. • The eco-friendly and cost-effective nature of KGM offers a sustainable alternative to traditional depressants like sodium silicate. • DFT simulations corroborate experimental findings, confirming strong adsorption of KGM on calcite, providing a mechanistic basis for its use.