Analysis of Spodumene Beneficiation Methods

Basic Information and Beneficiation Methods of Spodumene

Spodumene mainly originates from granite pegmatite deposits. Its gangue minerals are primarily silicate minerals with properties similar to spodumene, including quartz, potassium feldspar, and sodium feldspar. Industrially, spodumene beneficiation has developed several mainstream technologies, encompassing hand sorting, flotation, thermal cracking, magnetic separation, heavy media separation, and combined beneficiation methods. These methods rely on the differences in physical and chemical properties between spodumene and gangue minerals to achieve separation, meeting the industrial demand for spodumene concentrate. Among these, flotation is the most widely used due to its significant advantages.

Mainstream Beneficiation Methods of Spodumene

Flotation is the most widely used core method in spodumene beneficiation, mainly divided into two types: direct flotation and reverse flotation. The core principle of direct flotation is to use fatty acids and their saponifications as collectors, causing spodumene particles to adhere to the surface of air bubbles and float to the surface for recovery. Reverse flotation, on the other hand, uses inhibitors to suppress spodumene flotation while employing amine collectors to float gangue minerals such as quartz and feldspar, thus achieving efficient separation of spodumene from gangue minerals. In practical industrial applications, direct flotation has become the mainstream flotation method due to its advantages of simple process flow, low equipment investment, low production cost, and high spodumene recovery rate.

Hand sorting is a traditional separation method. Its core is that workers manually select spodumene minerals from the ore based on their color, shape, and other external characteristics, using a sorting belt or hand sorting table. This method is suitable for separating well-crystallized, coarse-grained spodumene and is often used as a pre-selection step in production to process ores with high waste rock content. It can effectively improve ore grade, reduce subsequent workload, optimize the process flow, and save costs. However, with declining ore grades and technological advancements, hand sorting has gradually fallen out of widespread use.

Thermal cracking is a method of separation that utilizes temperature control. Its core principle is to alter the crystal structure of the ore by adjusting the temperature. Spodumene itself has a stable structure and relatively stable chemical properties, and it does not readily react with acids or alkalis. However, when heated to temperatures above 1000℃, its crystal structure transforms, forming β-spodumene. This results in a significant change in its physicochemical properties, making it easier to crush and grind. Meanwhile, the properties of gangue minerals such as quartz remain stable and do not undergo significant changes. Subsequent processing steps after high-temperature roasting, such as cooling, crushing, and screening, separate spodumene concentrate to meet industrial production needs.

Heavy media separation separates minerals based on differences in density. Its core principle is to use a heavy suspension or liquid with a density between spodumene and gangue minerals as the separation medium, allowing minerals of different densities to be separated by settling or floating. For example, when separating spodumene from feldspar and quartz, tribromomethane, tetrabromoethane, or a heavy suspension prepared from iron powder can be used as the medium to achieve efficient separation.

Magnetic separation, based on the magnetic differences between different minerals, is an important auxiliary purification method in spodumene beneficiation. In spodumene ore, the content of magnetic impurity minerals (mainly including tantalum-niobium minerals, iron-bearing tourmaline, and other iron-containing minerals) is usually low. Magnetic separation can effectively separate these magnetic impurities from spodumene through the action of a magnetic field. This not only removes impurities but also further improves the purity of the spodumene concentrate, ensuring the quality of subsequent processing and utilization.