Tantalum-niobium ore often coexists with minerals such as zircon, ilmenite, and rutile in coastal placer deposits. Its effective separation primarily relies on differences in physical properties like density and magnetism between the valuable minerals and the gangue. The following sections systematically describe the typical beneficiation process flow and related equipment for tantalum-niobium ore from coastal sands.
I. Washing and Screening
After mining, the raw ore first enters a trommel screen for washing and preliminary screening. This step aims to remove impurities like clay and organic matter and to classify the ore by particle size, providing suitably sized material for subsequent gravity separation. The trommel screen effectively cleans impurities adhering to the ore particle surfaces during the washing stage and screens out oversized gravel, obtaining fine-grained ore sand that meets the requirements.
II. Chute Gravity Separation
The screened fine-grained ore sand enters spiral chutes for initial separation based on density differences between minerals. In this stage, tantalum-niobium ore, along with other high-density minerals like zircon and cassiterite, is concentrated in the concentrate trough, achieving pre-concentration through roughing and creating favorable conditions for subsequent cleaning stages.
III. Shaking Table Concentration
The tailings from the spiral chute gravity separation (primarily containing zircon, cassiterite, tantalum-niobium ore, etc.) are further fed to a shaking table for separation. Utilizing the shaking table's asymmetrical reciprocating motion and thin-layer water flow, low-density gangue minerals like silica sand are effectively removed, resulting in a mixed concentrate primarily composed of zircon, cassiterite, and tantalum-niobium ore.
IV. Magnetic Separation
The aforementioned mixed concentrate is dried and then fed into a three-disc magnetic separator for separation. By precisely adjusting the magnetic field intensity, effective separation is achieved by leveraging the magnetic differences between the various minerals. Tantalum-niobium ore typically exhibits weak magnetism and can be separated and extracted under an appropriate magnetic field strength, ultimately yielding a high-quality tantalum-niobium concentrate.
The above describes the typical beneficiation process flow for tantalum-niobium ore from coastal placer deposits.