SYNTHESIS OF FLOTATION BASED SEPARATION SYSTEMS
In this work a methodology is presented for defining the optimal configuration for flotation circuit and selection of appropriate equipment for the process. The problem is represented by three hierarchized superstructures. The first level represents separation tasks, which include: feed processing, concentrate processing, and tail processing. The second level represents the stream network needed to carry out each tasks. Where for each task a superstructure is developed which includes several operational stages. At the third level, several equipment alternatives are considered for each stage. The equipment discussed in the model includes flotation column and flotation cell banks, with and without grinding. The optimal selection of the circuit is made with an appropriate objective function, upon which the values of the operational and structural variables may be determined. The problem is formulated using disjunctive programming, which is converted to a MILP problem. The model includes mass balance, equipment models, operational conditions, and logic relationship. The paper presents an example to illustrate its application for effective design of a copper concentration plant.
Column flotation circuits in Chilean copper concentrators
Abstract This paper reviews the column flotation practice in the largest Chilean copper-moly concentrators where this process unit has been increasingly chosen to replace multi stage cleaning circuits in new and existing operations. Process flowsheets incorporating columns are presented for selected concentrators. Procedures for scaling up, and process control are also illustrated.
Integrating Al with NiO nano honeycomb to realize an energetic material on silicon substrate
Nano energetic materials offer improved performance in energy release, ignition, and mechanical properties compared to their bulk or micro counterparts. In this study, the authors propose an approach to synthesize an Al/NiO based nano energetic material which is fully compatible with a microsystem. A two-dimensional NiO nano honeycomb is first realized by thermal oxidation of a Ni thin film deposited onto a silicon substrate by thermal evaporation. Then the NiO nano honeycomb is integrated with an Al that is deposited by thermal evaporation to realize an Al/NiO based nano energetic material. This approach has several advantages over previous investigations, such as lower ignition temperature, enhanced interfacial contact area, reduced impurities and Al oxidation, tailored dimensions, and easier integration into a microsystem to realize functional devices. The synthesized Al/NiO based nano energetic material is characterized by scanning electron microscopy, X-ray diffraction, differential thermal analysis, and differential scanning calorimetry.