5.2.6 ( Kohmuench et al., 2006) shows the schematic diagram of a teeter-bed separator. Teeter-bed separator works on hindered settling principle where the counter-current flow of water and material when encounter in the hindered settling zone then the separation happens based on the specific gravity difference. Being the vertical arrangement, the floor space occupied by teeter-bed separator is comparatively less than that of spiral for the similar throughput capacity. Teeter-bed separator may be considered as an alternative for offshore pre-processing operations given that the density difference between the heavy mineral and sand is up to the mark and the particles size of the extracted unconsolidated material from the bottom of the sea to be in the range. The effect of wave action on the performance of teeter-bed hydro-separator would be minute as the principle of hindered settling enhance with fluidized bed separation would not be affected majorly due to external force ( Kohmuench et al., 2006).

The teeter-bed separator could be an alternative to be looked at for material having size ranging −2.00mm +0.075mm and having difference in specific gravity >0.1.

On land, for the same condition spiral concentrator may be ideal choice to separate the heavy mineral from silica as it have high capacity and low floor space index but for the offshore purpose, the performance of spiral separators may not be the same as onshore due to unduly motion of the ship due to wave action, the principle of flowing film concentration get affected and the effective segregation of particles according to specific gravity could not be attained. Gravity separating tables also take a lot of space, which is a serious disadvantage for use on offshore vessel. To counteract the motion of the ship due to wave action a stabilized platform could be envisaged, but wet, open techniques still seem difficult to perform. Plants with fewer processing stages are easier to operate, easier to control, and quicker to commission.Īs the movement of the vessel, as discussed above, due to wave action has especially an impact on wet techniques, making gravity separating tables, froth flotation, and jigging less efficient. Fewer processing stages mean reduced power consumption and a decreased need for peripheral equipment, such as pumps, motors, control circuitry, sumps, intermediate launders, and distribution systems. Associated advantages include cheaper plants with smaller footprints that can be readily relocated if necessary. The high concentrate grades and very high recoveries are achievable on these types of spirals in a single pass will result in concentrator plants that are greatly simplified and capable of higher overall processing performance. It is also important to maintain the center of gravity/inertia of the entire system while in motion otherwise with a slight impact of wave or wind the entire processing plant has a chance to get toppled.ĭifferent types of high-performance spiral separator with triple start type are available that has demonstrated exceptionally high separation efficiencies and high throughput on a number of different mineral sand feed types in rougher, scavenger, and cleaner duties. Hence plants need to be designed to accommodate such impact. Therefore, sufficient area needs to be offered to the material to have proper separation.

Wet gravity circuit