1, ore washing and screening
Ore washing is to separate ore from mud by hydraulic washing or additional mechanical scrubbing. Commonly used equipment includes ore washing screen, cylinder washer and trough washer.
Ore washing is often accompanied by screening, such as washing with water directly on the vibrating screen or sending the ore (clean ore) obtained by the ore washer to the vibrating screen for screening. Screening can be used as an independent operation to separate products with different granularity and grades for different purposes.
2. Re-election
Gravity separation is only used to separate manganese ore with simple structure and coarse disseminated particle size, especially manganese oxide ore with high density. The commonly used methods are dense medium beneficiation, jigging beneficiation and shaking table beneficiation.
At present, the technological process of treating manganese oxide ore in China is generally to crush the ore to 6 ~ 0 mm or 10 ~ 0 mm, then group it, jiggle it in coarse fraction, and send it to a shaking table for selection in fine fraction. Most of the equipment is Haze reciprocating jig and 6-S table.
3. High intensity magnetic separation
Manganese ore belongs to weakly magnetic minerals [specific magnetization coefficient x =10×10-6 ~ 600×10-6cm3/g], and magnetic field intensity ho = 800 ~1600ka/m (1g).
Because of its simple operation, easy control and strong adaptability, magnetic separation can be used for the separation of various manganese ores and plays a leading role in manganese ore dressing. Various new types of coarse, medium and fine grain high intensity magnetic machines have been successfully developed. Medium-sized high-intensity magnetic separators are widely used in manganese mines in China, and coarse-sized and fine-sized high-intensity magnetic separators are gradually applied, while fine-sized high-intensity magnetic separators are still in the experimental stage.
4. Gravity and magnetic separation
At present, the newly-built and rebuilt gravity and magnetic concentrator in China includes Liancheng in Fujian, Longtou in Guangxi, Jingxi and Xia Lei manganese mines. For example, Liancheng Manganese Mine Gravity and Magnetic Concentrator mainly deals with leaching manganese oxide ore. High-quality manganese concentrate containing more than 40% manganese can be obtained by treating 30 ~ 3 mm ore washing with AM-30 jig, which can be used as raw material of battery manganese powder after manual separation and impurity removal. After the jigging tailings and clean ore less than 3mm are ground to less than 1m, the grade of manganese concentrate can be improved by 24% ~ 25% ~ 36% ~ 40% with high-intensity magnetic separator.
5. Strong magnetic separation
Only Zunyi Manganese Mine adopts high intensity magnetic separation process. The mine is low manganese, low phosphorus and high iron manganese ore, mainly manganese carbonate.
According to the industrial test, the grinding process adopts rod mill-ball mill stage grinding, and the equipment scale is φ2 100mm×3000mm wet mill. Shp-2000 high intensity magnetic separator is used for high intensity magnetic separation, and CHF aerated flotation machine is mainly used for flotation machine. After years of production tests, the performance is good, which is very suitable for mineral processing of Zunyi manganese mine. The successful test of strong magnetic flotation process and its application in production indicate that the deep separation of manganese ore in China has taken a big step forward.
6. Pyrolysis and concentration
Pyrolysis enrichment of manganese ore is a separation method to treat high phosphorus, high iron and poor manganese ore, which is generally called manganese-rich slag method. Essentially, it is a high-temperature separation method for selectively separating manganese, phosphorus and iron by controlling the reduction temperature of manganese, phosphorus and iron in blast furnace or electric furnace.
China has used pyrometallurgical concentration for nearly 40 years. 1959 The trial was carried out in a 9.4m3 small blast furnace in Zijiang Iron Works, Shaoyang, Hunan Province, and preliminary results were obtained. Subsequently, in 1962, Shanghai Ferroalloy Plant and Shijingshan Iron and Steel Plant used blast furnaces to smelt manganese-rich slag respectively. 1975 Hunan Manaoshan manganese mine blast furnace not only produced manganese-rich slag, but also recovered lead, silver and pig iron (commonly known as semi-steel) from the bottom, which provided a basis for comprehensive utilization. Since 1980s, the production of manganese-rich slag has developed rapidly, and it has been developed in Hunan, Hubei, Guangdong, Guangxi, Jiangxi, Liaoning, Jilin and other places.
Pyrolysis enrichment process is simple and production is stable. Iron and phosphorus in the ore can be effectively separated to obtain manganese-rich slag with low iron and phosphorus, which generally contains 35% ~ 45% manganese, Mn/Fe 12 ~ 38, P/Mn.
7. Chemical manganese separation method
There are many chemical mineral processing methods for manganese, and a lot of research work has been done in China, among which there are many experiments, and the most promising ones are sodium dithionite method, hausmannite method and bacterial manganese leaching method. At present, it has not been put into industrial production.