Oil emulsions are systems of immiscible liquids in which one liquid is dispersed in the other in the form of small droplets. Usually, one of the phases is water, while the other is a liquid immiscible with water, called the oil phase. Due to its origin, the phase separation process in the emulsion results in a separated oil phase and the generation of post-process wastewater. In such industrial effluents, heavy metal ions are very often present in high concentrations and need to be removed. This paper presents a method for the neutralisation and precipitation of heavy metals from industrial wastewater (after emulsion processing) using precipitating agents and mineral flocculants. The research carried out focused on determining the possibility of effective reduction of heavy metals using two concentrations of precipitating agents from the sodium polysulphide group (0.2 and 1.0 ml/l) and two concentrations of mineral flocculants from the aluminosilicate group (0.5 and 2.0 g/l). A high degree of reduction of the analysed heavy metals, i.e. Cd, Ni, Cr, Pb, Zn, Cu, was achieved.