With the continuous adjustment of the energy structure and the successive introduction of subsidy policies in various countries, new energy vehicles have shown a blowout development. As the core material of new energy batteries, lithium resources are in strong demand and prices have been rising. The supply of upstream lithium resources has also become the focus of attention. To get a usable lithium battery, lithium ore first goes through a complex beneficiation process. At present, the known lithium ore beneficiation technologies include manual separation, flotation separation, combined method, magnetic separation, thermal cracking, radioactive separation, particle flotation, etc. In actual production, manual separation, flotation method, and combined beneficiation method are more common.
Use the table of contents below to navigate through the guide:
01Lithium manual separation technology
The manual separation method is a ore benefication method in which the lithium ore minerals and the gangue minerals are initially separated by manual sorting. This method is suitable for concentrate enrichment, large crystal spodumene, beryl, etc. The selected particle size is about 10-25 mm. The characteristics of the manual separation method are relatively low labor efficiency, high labor intensity, low selection indicators, and serious waste of resources.
02Lithium ore flotation separation technology
The research and application of flotation separation process was earlier, and industrial flotation method was used for the production of lithium concentrate. In the 1930s, flotation was an important lithium ore beneficiation method. The main minerals containing lithium can be separated by flotation method, which is widely used in actual production. Positive flotation and reverse flotation are two different flotation methods for lithium ore.
1. Lithium ore positive flotation
Positive flotation refers to the process of preferential flotation of lithium concentrate. The finely ground lithium ore pulp is stirred and scrubbed to remove the impurities on the surface after adding sodium hydroxide. Collectors such as oleic acid and its soaps then float the ore particles into the foam product in an acidic medium, after which the lithium concentrate is obtained. The concentrate is further processed to prepare lithium carbonate for use in batteries.
2. Lithium ore reverse flotation
Reverse flotation means that in the finely ground lithium ore slurry, in the alkaline medium regulated by lime, adding dextrin and starch regulators to inhibit lithium concentrate, and then using cationic collectors to remove silicate gangue. A method of sorting minerals that emerge. In reverse flotation, the product left in the tank is spodumene concentrate.
03Combined lithium ore beneficiation technology
For complex and refractory lean and fine lithium ore, it is difficult for a single flotation method to achieve the expected beneficiation index, and a combination of multiple flotation processes can be selected. Common processes include flotation-magnetic separation process, and gravity-flotation-magnetic separation combined process.
1. Combined flotation-magnetic separation method
When the combined process of flotation and magnetic separation is applied to the lithium concentrate containing more iron, in order to obtain low-iron spodumene, the subsequent magnetic separation method can be used to improve the quality of the lithium concentrate.
2. Gravity-flotation-magnetic separation combined method
According to the density difference between spodumene and gangue ore, the lithium ore with coarser particle size is sorted first. It should be noted that when the density difference between spodumene and gangue is greater than 0.2~0.5g/cm3, it is suitable to use a vibrating table or a jig for separation. When the density difference is less than 0.2~0.5g/cm3, the resuspension method can be used for separation. The lithium ore from gravity separator can enter the flotation stage after desliming. The lithium concentrate after flotation needs to be further removed iron impurities to improve the quality of the lithium concentrate, and finally obtain a high-grade concentrate.
As the "new energy of the 21st century", the demand for lithium is rising, and the development and utilization of lithium resources is also particularly important. Xinhai suggests that in the process of ore beneficiation, appropriate mineral beneficiation methods should be selected in combination with the components and properties of specific lithium deposits, so as to realize scientific, economical and efficient development and utilization of lithium resources.