Most manganese ore is a fine-grain, and contains phosphorus ore, iron ore and associated minerals, which brings a great difficulty to beneficiation processing. At present, the commonly used manganese ore beneficiation methods are mechanical beneficiation methods (washing, screening, gravity separation, strong magnetic separation and flotation), as well as special beneficiation methods (fire enrichment, chemical beneficiation, etc.).
1. Washing and sieving
Washing is the separation of ore and mud under hydraulic, mechanical and self-friction action, which
improves the ore grade. Main ore washing equipment includes ore trommel screen, cylinder trommel scrubber and tank washing machines.
The washing is often accompanied by screening, and the screen machine separates the cleaned ore into different sizes
for use in a different area.
2. Gravity separation
Gravity beneficiation is based on the difference in density and particle size of the mineral. The shape of
the mineral particles affects the accuracy of sorting by density to some extent. Gravity separation can be used for concentrating, also for tailing processing and preconcentration. In addition, gravity separation generally consists of a combination process with magnetic separation and flotation.
The density of manganese oxide ore is generally about 3.7~3.9t/m3, which is significantly different from silicate type gangue. Commonly used gravity separators include mineral jigs, shaker table, cyclones, chutes, and the like.
The density of manganese carbonate ore is 3.3~3.6t/m3, which has a small difference from the density of gangue. It
needs to be separated by heavy medium separators.
3. Strong magnetic separation
Manganese mineral is a weak magnetic mineral ( the specifical magnetization coefficient x=10×10-6~600×10-6cm3/g ), and it can be recovered in a strong magnetic field magnetic separator with a magnetic field strength Ho=800~1600kA/m (10000~20000oe), the manganese grade is increased by 4% to 10%.
The magnetic separators are easy to control, suitable for various manganese ore process. The most commonly used machine is the medium-grain strong magnetic separator, followed by the coarse-grained and fine-grained magnetic separators, the micro-grain-strong magnetic separator is still in the experimental stage.
10~25mm, using CGD-38 roll strong magnetic separator;
1~10mm, using CS-1, CS-2 series strong magnetic separators;
0.05~1mm, using ShP and SZC series strong magnetic separator.