Take you to understand common lithium ore processing methods

The editor starts with salt lake brine lithium ore and spodumene ore, and takes you through common lithium ore processing methods.

1. Salt Lake brine lithium ore processing method

In such deposits, lithium is dissolved in saline groundwater and mainly exists in the form of intergranular brine, interstitial brine and surface brine. The main methods for extracting lithium from lithium-containing lake brine include precipitation, calcination and leaching, carbonization, ion exchange adsorption, etc.

1) Precipitation method

The principle of the precipitation method is to extract minerals in the order of boron, magnesium, and lithium based on the composition characteristics of salt lake brine and the different solubilities of different minerals. The process of obtaining lithium carbonate by this method does not require high temperature and high pressure, and there is no waste gas emission. It is a relatively simple method with low energy consumption and low pollution.

2) Calcination and leaching

This method is used to treat the mixture obtained by evaporating brine after boron extraction. After the concentrated lithium-rich liquid is added with lime milk to remove sulfate and chlorite, it is calcined, extracted, precipitated, solid-liquid separated, and dried to obtain lithium carbonate solid.

3) Carbonization method

This process has certain requirements on the raw ore composition and is more suitable for carbonate salt lakes with low magnesium and lithium ratios. The principle is that lithium carbonate reacts with carbon dioxide and water to form lithium bicarbonate with higher solubility, which is separated from other minerals. In industrial production, the process flow generally includes the following steps: washing, separation, water immersion, carbonization, and pyrolysis.

2. Spodumene processing method

Spodumene mainly produces muscovite-type and limonite-type pegmatites, often associated with limonite, beryl, columbite-tantalite, tourmaline and other minerals. This type of mineral usually contains a large amount of clay minerals and is prone to turbidity during the grinding stage, so the grinding fineness should be strictly controlled. Therefore, the particle size and fineness of grinding should be strictly controlled. Common beneficiation methods for spodumene include hand selection, flotation, heavy liquid separation, magnetic separation, etc.

1) Flotation method

Flotation is a commonly used method for separating pyroxene. The important links in the flotation process are stirring intensity, temperature and the ratio of regulators.

Commonly used spodumene flotation reagents are usually two soaps and "three bases". The "three bases" refer to sodium carbonate, sodium sulfide and sodium hydroxide. The "two soaps" refer to naphthenic acid soap and oxidized paraffin soap. Adding "three bases" "Alkali" keeps the pH value of the slurry within the range of 4.0 to 9.0 and reduces the impact of calcium on flotation. Using "second soap" can easily float the pure mineral spodumene to the surface.

Of course, during the flotation process, flotation indicators are greatly affected by water quality and environmental factors.

2) Heavy liquid separation

Due to its relatively high density, spodumene can be chosen as a heavy mineral. Therefore, media such as bromoform and tetrabromoethane are usually used to adjust resuspension. Since tribromoform and tetrabromoethane are volatile and irritating to human mucous membranes and hearing organs, the heavy liquid separation method is rarely used in industrial production.

3) Differences in magnetic separation

Since spodumene minerals often contain small amounts of iron impurities, magnetic separation methods can be used to separate iron impurities from spodumene concentrate or spodumene mica.

In addition to the above single beneficiation method, due to the complex association between pyroxene and other minerals, combined beneficiation methods are usually used to treat pyroxene minerals, such as "gravity separation-magnetic separation-flotation".

Gravity separation is used to screen tantalite niobate and cassiterite, magnetic separation is used to separate tantalite niobate coarse concentrate, and flotation is used to screen pyroxene.

Compared with a single mineral processing method, the combined mineral processing method can achieve more effective comprehensive recovery of resources.

The above are some common lithium mineral separation methods. For the production of mineral processing plants, it is very important to understand the composition and properties of minerals. If you have lithium ore to process, we can provide you with process design and equipment. You are welcome to leave a message on our website, or consult online customer service for details.