Rare earth ore flotation - collector application and purification extraction

 In recent years, rare earth elements have been increasingly used in military, electronics, artificial intelligence and other fields. The introduction of trace rare earth elements can greatly improve the performance of related products and become the "vitamin" of modern industry. 

Most rare earth elements are found in rare earth ores. However, rare earth elements in rare earth ores are numerous and complex in composition, and often coexist with quartz, barite, fluorite, silicates, etc. At the same time, rare earth minerals have similar solubility, surface properties and floatability as calcium-containing gangue minerals such as fluorite. Therefore, if you want to obtain pure and single rare earth products, you must first crush and grind the rare earth ore, and then perform necessary flotation operations to screen and remove specific mineral powders, and obtain concentrates for decomposition and refining. 

The effect of flotation collectors on the enrichment of rare earth minerals

A good flotation process can effectively increase the enrichment of rare earth minerals in rare earth concentrates, that is, to improve the grade of rare earths. In order to achieve the expected flotation effect, in most cases, it is necessary to add surfactants and other agents to the rare earth ore flotation system. The wide variety of rare earth flotation surfactants mainly include frothers, collectors and regulators.

Zhang Jun et al. used chelated hydroxamic acid QP as a collector, water glass as a suppressant for silicate gangue minerals, and sodium carbonate as both a rare earth slurry pH regulator and a carbonate gangue mineral suppressant. Through a rough-sweep-fine flotation process, the ReO grade increased from 3.64% to 15.34%, and the rare earth recovery rate increased to 75.22%.

The influence of flotation collectors on the purification and extraction process of rare earth minerals

The flotation collector not only significantly affects the recovery rate of rare earth minerals, but also directly affects the customization of the flotation process.

(1) The selection and application of flotation collectors are determined by the composition and characteristics of the minerals

Rare earth ores contain barite, fluorite, calcite and other gangue minerals with similar floatability to rare earth minerals. It is necessary to rationally select and use collectors, inhibitors and activators in combination to effectively separate rare earth minerals from associated gangue minerals. For example, the commonly used flotation collectors for fluorocarbon cerium rare earth ore are hydroxamic acid, phosphorus-containing, sulfur-containing and carboxylic acid collectors.

(2) The collector has an important influence on the process indicators of the flotation process during flotation.

The process of collector interaction with the mineral surface includes two control steps: the diffusion of the collector in the hydration layer and the surface film layer of the mineral surface [18]. The interfacial chemical changes involved have an important influence on the flotation indicators of rare earths. Therefore, taking corresponding measures to control the diffusion step of the flotation process can effectively improve the process indicators of the flotation process.

(3) Enhancing the matching between factors affecting the flotation process can effectively improve the grade of rare earths

The flotation process is affected by factors such as collector structure and properties, mineral powder particle size, acidity, active sites, reagent concentration, action time, etc. If the "matching effect" between factors affecting the flotation process can be considered, it can effectively improve the ReO grade in rare earth mineral powder and increase its recovery rate, and can also effectively solve the rationality of the selection of flotation process conditions and the effective use of raw materials and auxiliary materials, so as to achieve the purpose of cost saving and environmental protection.