3 Major Rare Earth Ore Mineral Processing Methods

01Rare earth ore flotation process

Flotation is one of the main process methods in rare earth ore concentrators, and it is almost inseparable from flotation. This method uses the difference in surface wettability of rare earths and associated minerals for selection. By adding flotation agents, with the help of the buoyancy of the air bubbles, the useful rare earth minerals are attached to the air bubbles and then floated up to complete the separation, and finally obtain qualified rare earth concentrates.

In general, the flotation method is mostly suitable for sorting rare earth ores with finer particle size. For example, for the separation of bastnaesite and monazite, the pH value of the pulp is determined to be in the range of 4.5 to 5.5, adding alum as the inhibitor of monazite, and phthalic acid as the collector of bastnaesite, and after a The flotation process of roughing-two fines-two sweeps can obtain better bastnaesite and monazite concentrates.

02Rare earth ore gravity separation process

The separation of rare earth ores by gravity separation is mainly a process of separating minerals based on density differences in a certain fluid medium, and is generally used in small and medium-sized rare earth ores concentrators. The process is mainly to roughly select the qualified ore particles (-2mm range) obtained after grinding and classifying with a shaking table, and then sweep the obtained roughed tailings through a shaking table, and obtain the roughened concentrate. The concentrate can be used as the final rare earth concentrate.

Gravity separation is a relatively simple process for sorting rare earth ores, but the resource recycling rate is low, generally only around 60%.

03Rare earth ore leaching process

Rare earth ore leaching processes can be divided into three types, namely barrel leaching, pool leaching and heap leaching. Among them, the bucket leaching method was applied earlier, because of its low efficiency, it has been replaced by pool leaching and heap leaching.

1. Rare earth ore pool leaching process: After the raw ore is fed into the leaching agent, the rare earth leaching solution is obtained, and then oxalic acid is added for precipitation, and then filtered, washed and repeatedly burned to obtain qualified rare earth concentrate. The cost of the rare earth beneficiation method is low, but the work efficiency is also low, and at the same time, more harmful ions will be generated during the leaching process.

2. Rare earth ore heap leaching process: Ammonium sulfate ((NH₄)₂SO₄) is used as the leaching agent, which has strong washing ability and strong selectivity for leaching ions, and can effectively reduce the leaching of harmful metal ions such as Ca²⁺ and Ba²⁺. In addition, NH⁴⁺ hardly precipitates with rare earth ions. Therefore, the separation efficiency of rare earth ore concentrate is higher. But overall, the heap leaching method is very destructive to the surrounding environment.

In addition to the above three single rare earth ore beneficiation processes, there are also multiple combined beneficiation processes such as magnetic separation, flotation, and gravity separation, which are mainly for separation and purification of some complex and difficult rare earth ores, such as flotation-gravity-flotation method, magnetic separation-gravity-flotation method and weak magnetic-strong magnetic-flotation method, etc. In the actual concentrator, the rare earth ore beneficiation method needs to be designed according to the nature and complexity of ore removal. Therefore, Xinhai Mining recommends that the rare earth ore beneficiation test should be carried out first, and the appropriate rare earth ore beneficiation process and complete set of rare earth ore beneficiation equipment should be designed through analysis, so as to effectively obtain the ideal rare earth ore concentrate.