The suspension of the copper droplets in the post-processing slag taken directly from the KGHM-Polska Miedź S.A. Factory (from the
direct-to-blister technology as performed in the flash furnace) was subjected to the special treatment with the use of the one of the typical
industrial reagent and with the complex reagent newly patented by the authors. This treatment was performed in the BOLMET S.A.
Company in the semi-industrial conditions. The result of the CaCO3, and Na2CO3 chemicals influence on the coagulation and subsequent
sedimentation of copper droplets on the crucible bottom were subjected to comparison with the sedimentation forced by the mentioned
complex reagent. The industrial chemicals promoted the agglomeration of copper droplets but the coagulation was arrested / blocked by
the formation of the lead envelope. Therefore, buoyancy force forced the motion of the partially coagulated copper droplets towards the
liquid slag surface rather than sedimentation on the crucible bottom. On the other hand, the complex reagent was able to influence the
mechanical equilibrium between copper droplets and some particles of the liquid slag as well as improve the slag viscosity. Finally, the
copper droplets coagulated successfully and generally, were subjected to a settlement on the crucible bottom as desired / requested.
The suspension of copper droplets in the slag is considered. The copper/slug suspension is delivered as the product from the direct-toblister
process which is applied in the KGHM – Polska Miedź (Polish Copper) S.A. factory. The droplets / slag suspension was treated by
a special set of reagents (patented by the authors) to improve the coagulation process. On the other hand, the observations are made to
estimate if the melting / reduction process in the furnace is sufficiently effective to avoid a remaining of carbon in the copper droplets.
The coagulation process was carried out in the crucible (laboratory scale). However, conditions imposed to the coagulation / solidification
process in the laboratory scale were to some extent similar to those applied usually in the industry when the suspension is subjected to the
analogous treatment in the electric arc-furnace. Some suggestions are formulated how to improve the industrial direct-to-blister process.