1. Washing and screening

Ore washing is the use of hydraulic washing or additional mechanical scrubbing to separate the ore from the mud. Commonly used equipment is ore washing screen, cylinder ore washing machine and trough type ore washing machine. Washing operations are often accompanied by screening, such as washing directly on the vibrating screen or sending the ore (clean ore) obtained by the washing machine to the vibrating screen for screening. Screening can be used as an independent operation to separate products of different particle sizes and grades for different purposes.

2. Re-election

At present, gravity separation is only used to separate manganese ore with simple structure and coarser grain size, and is especially suitable for manganese oxide ore with higher density. Commonly used methods are heavy medium beneficiation, jig beneficiation and shaking table beneficiation.

The current process of processing manganese oxide ore in my country is generally to crush the ore to 6 to 0 mm or 10 to 0 mm, and then group the ore, jigging for the coarse level, and sending it to a shaker for the fine level. The equipment is mostly Haz reciprocating jig and 6-S shaker.

3. Strong magnetic separation

Manganese minerals are weakly magnetic minerals [specific magnetic susceptibility X=10×10-6～600×10-6cm3/g], which can be used in a strong magnetic separator with a magnetic field intensity of Ho=800～1600kA/m (10000～20000oe) Recycling can generally increase the manganese grade by 4% to 10%.

Because of its simple operation, easy control, and strong adaptability, magnetic separation can be used for the separation of various manganese ore. In recent years, it has taken a dominant position in manganese ore beneficiation. Various new types of coarse, medium and fine-grained strong magnetic machines have been successfully developed. At present, the most common application of domestic manganese ore is the medium-grain strong magnetic separator, the coarse and fine-grain strong magnetic separators are also gradually being used, and the fine-grain strong magnetic separator is still in the experimental stage.

4. Heavy-magnetic separation

At present, domestic heavy-magnetic separation plants that have been newly built and rebuilt include Fujian Liancheng, Guangxi Leading, Jingxi and Xialei manganese mines. For example, the Liancheng Manganese Mine Heavy-Magnetic Separation Plant mainly processes leaching manganese oxide ore, and uses AM-30 jigs to process 30～3mm washed ore to obtain high-quality manganese concentrate with a manganese content of more than 40%. After selecting and removing impurities, it can be used as raw material for battery manganese powder. After the jig tailings and the cleaned ore diameters less than 3mm are ground to less than 1m, they are separated by a strong magnetic separator. The grade of manganese concentrate should be increased by 24% to 25%, reaching 36% to 40%.

5. Strong magnetic-flotation

At present, only Zunyi manganese ore is used in the strong magnetic-flotation process. The ore is a low-manganese, low-phosphorus, and high-iron manganese ore based on manganese carbonate ore. According to industrial experiments, the grinding process adopts rod mill-ball mill stage grinding, and the equipment scale is φ2100mm×3000mm wet grinding machine. The strong magnetic separation adopts the shp-2000 strong magnetic machine, and the flotation machine mainly uses the CHF type inflatable flotation machine. After years of production test, it has good performance and is very suitable for Zunyi manganese beneficiation application. The successful test of the strong magnetic-flotation process flow and its application in production indicate that the deep separation of manganese ore in my country has taken a big step forward.

6. Fire enrichment

Pyroconcentration of manganese ore is a sorting method for processing high-phosphorus, high-iron and difficult-to-select poor manganese ore, generally called manganese-rich slag method. Its essence is a high-temperature separation method that uses different reduction temperatures of manganese, phosphorus, and iron, and controls the temperature in a blast furnace or electric furnace to selectively separate manganese, phosphorus, and iron.

Our country has adopted pyro-enrichment for nearly 40 years. In 1959, Hunan Shaoyang Zijiang Iron Works conducted a test on a 9.4m3 small blast furnace and obtained preliminary results. Subsequently, in 1962, Shanghai Ferroalloy Plant and Shijingshan Iron and Steel Plant smelted manganese-rich slag in blast furnaces. In 1975, the blast furnace of Mannaoshan Manganese Mine in Hunan not only produced manganese-rich slag, but also recovered lead, silver and pig iron (commonly known as semi-steel) at the bottom of the furnace to provide a basis for comprehensive utilization. Since the 1980s, the production of manganese-rich slag has developed rapidly, and the production of manganese-rich slag has been developed in Hunan, Hubei, Guangdong, Guangxi, Jiangxi, Liaoning, Jilin and other places.

The pyroconcentration process is simple and stable, and can effectively separate the iron and phosphorus from the ore to obtain manganese-rich, low-iron, and low-phosphorus manganese-rich slag. This manganese-rich slag generally contains Mn35%-45%. Mn/Fe12-38, P/Mn<0.002, is a high-quality manganese alloy raw material, and it is also an artificial rich ore that is difficult for ordinary natural manganese rich ore to achieve the above three indicators at the same time. Therefore, pyro-enrichment is a promising method for beneficiation of high-phosphorus, high-iron and low-manganese refractory ore in my country.

7. Chemical selection of manganese

There are many chemical beneficiation methods for manganese, and a lot of research work has been carried out in our country. Among them, there are many tests and the promising ones are: the dithionite method, the black manganese method and the bacterial manganese leaching method.