Five major beneficiation processes for manganese carbonate

Manganese has a variety of valence states and excellent physical and chemical properties, and is widely used in industrial fields such as steel, metallurgy and machinery. Manganese carbonate ore is one of the important raw materials for manganese recovery. The main minerals include rhodochrosite, calcium rhodochrosite, manganese calcite and rhodochrosite. The gangue minerals are mainly silicate and carbonate minerals, accompanied by a small amount of impurities such as sulfur and iron. Its mineral processing technology covers washing, gravity separation, magnetic separation, flotation and leaching, etc., which needs to be optimized according to the properties of the ore to improve resource utilization efficiency and economic benefits.

1. Manganese carbonate washing process

Ore washing is a pretreatment process that uses hydraulic, frictional and mechanical forces to clean the ore surface mud during the ore dressing process. It is usually used before ore crushing or selection to improve the ore grade and reduce the impact of ore mud on subsequent operations. Manganese carbonate ore has a low mud content, and the degree of cementation between mud and ore is weak. It is generally an easy-to-wash ore. It can be washed with a vibrating screen, and the product under the screen is desludged and graded with a spiral classifier.

2. Manganese carbonate gravity separation process

Gravity separation is a technical means to achieve separation based on the density difference of mineral particles through different falling speeds in the medium. The density of manganese carbonate ore is generally 3.6-2.9g/cm³. Due to the small density difference, the single gravity separation method has limited effect on fine-grained manganese carbonate ore. However, for coarse-grained manganese carbonate ore, gravity separation has the advantages of simple process, low cost and low environmental pollution, and is preferred.

In practical applications, carbonate minerals such as calcium rhodochrosite and manganese calcite can be classified by heavy medium hydrocyclone and then enter the jig for gravity separation after washing. Gravity separation equipment includes heavy medium separators, shaking tables, jigs, etc. When single gravity separation cannot meet the indicators, it is usually used in combination with magnetic separation or flotation processes to further improve separation efficiency and concentrate quality.

3. Manganese carbonate magnetic separation process

Manganese carbonate ore is a weakly magnetic mineral. In the ore dressing process, magnetic separation is widely used because of its small footprint, low energy consumption, low cost, and economic and environmental protection. Different magnetic separation methods can be selected for different types of manganese carbonate ores. For high-iron manganese carbonate ore, wet weak magnetic separation can be used for roughing, followed by high-gradient strong magnetic separation to achieve effective separation and recovery of iron and manganese. For high-sulfur manganese carbonate ore, whose main gangue minerals are dolomite, pyrite, etc., the combined process of strong magnetic separation and flotation can also obtain better mineral processing indicators. When processing low-grade manganese carbonate ore, a high-gradient magnetic separator can be used to enrich it through a one-roughing and one-sweeping mineral processing process. Magnetic separation equipment mainly includes dry magnetic separators, wet magnetic separators and high-gradient magnetic separators, etc., which need to be flexibly selected and used according to the specific characteristics of the ore and the mineral processing requirements.

4. Manganese carbonate flotation process

Manganese carbonate ore has many associated gangues, complex composition and fine embedded particle size. The flotation process can effectively enrich the fine-grained manganese carbonate ore. Usually, manganese carbonate ore adopts positive flotation process. In the flotation process, the collectors are mostly carboxylic acid agents such as oleic acid and sodium oleate, oxidized paraffin soap, sodium petroleum sulfonate, tall oil, cyclohexane acid, and alkyl hydroxamic acid. In the flotation process, fuel oil and kerosene are often added as promoters to promote the hydrophobic effect of the collector on the mineral surface. In addition, by rationally selecting the combination of reagents and their dosage, the flotation index can be effectively optimized and the beneficiation effect can be improved.

5. Manganese carbonate leaching process

Leaching is to change the properties of minerals by chemical methods to achieve comprehensive recycling of minerals. The leaching process of manganese carbonate ore mainly includes three methods: pre-roasting leaching, direct acid leaching and microbial leaching.

Pre-roasting leaching: Reduce high-valent manganese to low-valent manganese, and recover manganese in the form of ions during the leaching process, which is suitable for recovering high-valent manganese resources.

Direct acid leaching: Directly act on manganese carbonate ore through sulfuric acid, hydrochloric acid or industrial waste acid, and strictly control parameters such as temperature, solid-liquid ratio, acid leaching time and stirring intensity.

Microbial leaching: Use acidic substances produced by microbial metabolites to act on ore, which has the advantages of less reagent demand, low cost and less environmental pollution, but the leaching speed is slow and the production conditions are required to be high. It is currently mainly used in laboratory research.

With the deepening of the refinement of manganese carbonate ore and the increase in the difficulty of mineral processing, a single mineral processing method can no longer meet the actual needs, so a combined mineral processing process is often used. Before operation, a comprehensive mineral processing test analysis should be carried out on the ore, and the process configuration should be scientifically optimized according to the properties of the ore to ensure an ideal return on investment and high-quality manganese carbonate concentrate.