The ore dressing processes are gravity dressing, magnetic dressing and floatation. As a result of the manganese ore exists inside the form of fine grains it is difficult to separate the monomer. Although the majority of the monomer had been separated it can be difficult to solve the problem in the separation in the finest. For that reason, manganese ore dressing is aggregate dressing. So named aggregate may be the mineral of relative high grade particles with coarse grains and effortless to become separated. The disadvantage of it's low grade of concentrate.
(1) Washing and re-dressing
Manganese carbonate dressing with sprinkle on vibration screen (Hongqi zone of Xiangtan Mine)
Manganese oxide dressing with primary and secondary dressing in double screw trough washer(Dongxiangqiao Mine). Changsha mining institute developed a brand new procedure of self-grinding size degradation process. It combines the method of grinding, erasing and washing. It has been used in dressing of loose manganese ores. It's a creative development of dressing approach.
The gravity dressing machine are jigging machine, shaking bed and high media drum separator, whirlcone, vibrating chute and etc. High media – intensive magnetic separation is applied for manganese carbonate. Disposal of wall rock is inside the initially stage, deep separation is in the second stage(Xiangtan Mine).
(2) Magnetic separation
Intense magnetic separation is the most extensively and effectively applied process. It has been rapidly created considering that China is open towards the outside world. All of the key manganese mines applied the approach. Even so, few with the mines use solely magnetic dressing. Most mines use combined method consisting of some of ore washing, gravity dressing, floatation and magnetic separation.
A lot of research operate on magnetic separation has been carried out. The machine for separation of coarse, intermediate and fine particles, both permanent and electricmagnetic induction, had been developed. Neodymium-iron-boron permanent magnetic is utilized in medium-intense magnetic field separator of PMHS series. The magnetic field intensity of separation is 1.1 T. The upper limit of separation is as high as 50mm. CS-1, CS-2 and shp-mode is often a much better applications. The upper limit of separation is 5-7 mm, the maxim intensity is 1488kA/m for CS-1 mode. The upper limit of separation is 10-15 mm, the maxim intensity is 1390kA/m for CS-2 mode. The upper limit of separation is 1 mm, the maxim intensity is 640-1600kA/m for shp mode.
(3) Floatation and others
Floatation dressing isn't typical inside the Chinese manganese mines. Zunyi Manganese Mine made use of a joint procedure of intense magnetic and floatation. The chemical substances of pertrolium sodium sulphonate and oxidized paraffin soap are utilized to catch rhodochrosite in floatation dressing. Chemical dressing, selective precipitation and concentrate dehydration and other process had been studied. Even so, it is actually far to be applied in production. Via arduous effort in 20 years we have made wonderful success inside the analysis of manganese dressing.
The key ore progress is as follows:
(1)     Pre-separation and coarse particles dressing. Intense magnetic dressing and gravity dressing of coarse particles are feasible for various ores of manganese carbonate. The recovery was 3%-5% increased thereby.
(2)    Many types of intense magnetic dressing machine have been used. They are: 80-1, CGD-38, CS-1, CS-2, CGDE-210, PMHIS, shp and so on.
(three)    Approach of dressing of fine particles was successful.
(4)    New process of comprehensive recovery of multi-elements manganese ore was successful.
(five)    Lots was done on manganese mineralogy.
Mineral constituents of fine particles had been defined by the quantity statistics of energy spectrum microprobe in the study with the states of manganese and phosphor and in the study of dephosphorization of high grade manganese ore. Forecast of theoretical specification of dressing was made by statistics of aggregate particles. Mineralogy studies had been carried out in 9 big and medium manganese mines. The basic conditions required for dressing approach and specification had been provided.