ADSORPTION OF 2-MERCAPTOBENZOTHIAZOLE ONTO PYRITE

The adsorption of a heterocyclic thioamide (such as 2-mercaptobenzothi azole (MBT) collector) on pyrite has been studied. 2-mercaptobenzoxazo le (MBO) and 2-mercaptobenzimidazole (MBM) were used in the tests as r eferences. The flotation of pyrite with MET, MBO, and MBM has also bee n investigated. Quantum chemical calculations carried out by the exten ded Huckel method for adsorption models, MBT ion-pyrite and MBT dimer- pyrite, are used to illustrate the electronic, binding and energy stat es of the two adsorption systems. It is demonstrated that MBT ions can be chemically adsorbed onto the pyrite surface by the formation of bo nds between sulphur and nitrogen atoms of MBT and iron atoms on the py rite surface. The adsorption of MBT dimer is more stable than that of MBT ion on pyrite. The adsorption of MBT on pyrite is further discusse d in terms of the adsorption model of MBT ions onto the pyrite surface with hydrogen and hydroxyl ions previously adsorbed. (C) 1998 Elsevie r Science B.V.