Improved flotation separation of cassiterite from calcite using a mixture of lead (II) ion/benzohydroxamic acid as collector and carboxymethyl cellulose as depressant

Tin and its compounds have a variety of applications. It is recovered as cassiterite from ore deposit by flotation. Traditionally, the use of fatty acids and their derivatives with limited selectivity of cassiterite over calcite (the main gangue mineral) has been replaced by benzohydroxamic acid (BHA). BHA shows poor collecting ability to cassiterite, even when lead nitrate (LN) is added as the activator. In this work, the flotation results show that cassiterite can be separated efficiently from cassiterite-calcite binary mixed minerals using a mixture of LN/BHA as collector and carboxymethyl cellulose (CMC) as depressant. The separation performance of the mixture of LN/BHA is much better compared with adding LN and BHA in sequence at the same dosage. Zeta potential measurements indicate that the mixture of LN/BHA exhibits much stronger ability to adsorb on cassiterite compared with adding LN and BHA in sequence even in the presence of CMC.