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Conventional hindered-bed separators are used extensively for classification and gravity concentration of minerals such as ore, coal, and titanium-bearing beach sands. The process can be inefficient due to wide variations in the solids content and size distribution of the feed. The poor efficiency has an adverse impact on plant performance (product recovery, concentrate quality and throughput capacity), and on operating costs (power consumption, water usage and reagent consumption).

Design improvements are needed to correct inefficiencies associated with conventional hydraulic separators. Compared with a conventional classifying machine, the CrossFlow design combines the use of an improved feed injection system and simplified water distribution system. This makes it possible to increase both the separation efficiency and throughput capacity, while eliminating mechanical problems associated with existing designs.

Operating demands, including power, water and maintenance, are expected to be significantly lower for the CrossFlow design when reporting on a per ton of concentrate basis because of higher throughput capacity. The HydroFloat separator , a novel air-assisted hydraulic concentrator , is an innovative process that combines the flexibility of a flotation process with the high capacity of a density separator. The machine's unique design features will make it ideal for recovering very coarse particles that are too large to be upgraded by existing froth flotation processes.

Fine particle classification is practiced at essentially all mineral and coal processing operations. Therefore, the entire industry is expected to benefit from the industrial research work outlined in this project. The proposed work will initially focus on only phosphate, mineral sands, and coal-related applications. However, the technological improvements will positively impact many other mining related applications.

These goals will be achieved through two phases. In Phase I, these new technologies will be further developed through systematic pilot-scale testing of key design and operating variables at three industrial sites. In Phase II, the technologies will demonstrate improved performance capabilities in field trials conducted at one of the industrial sites, using a production-scale prototype. Data from the pilot-scale and prototype tests will be used to develop simulation programs for process scale-up and to develop optimized high-efficient flowsheet.

Upon successful completion of Phase I, the industrial team members will evaluate the feasibility of upgrading existing processing circuits and/or installing new processing circuits based on the projected benefits. Virginia Tech and the University of Kentucky will assist with flowsheet design and projected processing performance, utilizing the simulator developed during Phase I of this project. The sand maker manufacturer will provide the design and engineering functions to scale up the unit for commercial production and will also manufacture the production-scale unit. As such, we will take a leading role in the long-term commercialization efforts for these new hammer crusher technologies.