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Diamond beneficiation
In China, diamond mine is located in Changde, Hunan Province, China. It is a fine placer ore bed. The main heavy ores cover diamond, gold, zirconite, rutile, ilmenite, hematite etc.. And during these minerals like gold, zirconite and ilmenite are higher relatively, and can be recovered. For gold, amalgamation can be used to make the job.
During the ore bed, diamond is uaually concentrated **4mm. The crystals are of high quality and its beneficiation is mainly jigging gravity separation. And jigger, cylinder-washing machines, single-spiral classifier, screening separators, hand-separation and amalgamator will be mainly involved.
This diamond mine in China firstly adopted multi-jigging( **6*8mm,   *8*4mm, *4*2mm, *2*1mm, *1*0.5mm) with the max. feeding size of *6mm. This processing line needs multi-layer screens, which makes the plants allocation hard and water-consumption large. And aiming at solving the difficulty and the sophistication, the single jigging can be used instead of multi-jigging.
From the beneficiation test, 
1) normal eccentric transmission jigger is not so good for the single-jigging. Diamond recovery is not so even because its coarse concentrate is little. The granularity composition of concentrate ore is unsuited with the raw ore, and lots of diamond will be lost.
2) Dissymmetric alternating motion device is inverted on the jigger as the transmission for the no-grading jigging to gain satisfied efficiency: high recovery rate and even working nature; size of concentrate is similar to that of the raw ore and high diamond content. But the device is not stable, and unadjustable, so it shall not be used on the jigger.
3) cam spring device is installed on the jigger for the no-grading jigging separation for high recovery rate and great working nature.
4) After the improvement of LTA jigger about the movable cone diaphragm, the jigging curve is sine wave with its high up-flow speed and short effecting time while down-flow speed is small and effecting time is long, so the diamond recovery and beneficiation efficiency is great.

The diamond mining separation is firstly the rough sepatation to remove most of the waste gangue. Gravity separation machines involved for the diamond rough separation are mainly pan-washing separation, jigging separation, and heavy-medium separation. All three methods workd on difference of density between diamond and waste gangue. And during the three methods, jigging separation is easy to operate, with its high recovery rate of **7% and good enrichment efficiency. Diamond jig separator have a large handling capacity and no requirements about the water quality.