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- January 17, 2023
- battery materials, battery recycling
- (0)
- 08 mins
Lithium Extraction From Salt Lakes Accelerates Industrialization
- The development progress of the salt lake is restricted
- The adsorption of lithium extraction presents high technical barrier
- Enterprises with technical advantages in lithium extraction process package design
According to the data, the world’s lithium resources in 2020 can be divided into two categories: salt lake resources and ore resources, of which salt lake brine accounts for nearly 60%. From the perspective of geographical segments, the proven lithium resources of the Lithium Triangle in South America accounted for 56%, and China ranked sixth, accounting for about 6%.
Compared with ore resources, the lithium extraction from salt lake brine has the following advantages:
- The total resource scale is dominant;
- The production cost is about 1/3 of the extraction of lithium from ore;
- The exploration period is short.
The development progress of the salt lake is restricted
The actual exploitation rate of salt lakes in China is low
Compared with South American salt lakes, China’s salt lake lithium resources are mainly characterized by high reserves but low grade and low exploitation and utilization:
- Qinghai Salt Lake: The ratio of magnesium to lithium is significantly lower than that of South America, and the lithium yield is low.
- Tibet Salt Lake: Although it has good resource advantages, it is subject to harsh natural conditions and is difficult to mine. The above factors together lead to the fact that although the reserves of lithium extraction from salt lakes in China are large, the output is limited, and the utilization rate of lithium resources in salt lakes is severely limited.
Adsorption and membrane coupling process has advantages
South America’s lithium-rich salt lakes have high grades and low magnesium-to-lithium ratios, so precipitation methods are often used. If the precipitation method is used in China’s lower-grade salt lakes, the lithium industry will drop significantly.
In order to solve the problem of the high ratio of magnesium to lithium in Qinghai Salt Lake, lithium extraction from old brine (that is, to form old brine by drying brine and potassium extraction first, enriching lithium ions and then extracting lithium) came into being.
Later, in order to solve the huge investment in the salt field system and the long-term problem of halogen drying, Chinese enterprises continue to carry out diversified innovations and upgrades in lithium extraction technology.
The adsorption of lithium extraction presents high technical barrier
The “adsorption and membrane” coupling process relies on material development and process package design. The adsorption section presents high technical barriers, and the replacement process of the membrane section is accelerated.
- Adsorption section: adsorption capacity, dissolution loss rate, etc. are the core indicators to measure the efficiency of lithium extraction adsorbents, and are further divided into aluminum-based, titanium-based and manganese-based adsorbents according to the degree of adaptation of specific brine types;
- Membrane section: In the part of magnesium-lithium separation, gradient coupling of membranes (reverse osmosis, nanofiltration membrane, ultrafiltration, etc., mainly organic membranes) is often used. The technical difficulties of this process section lie in the strength of membrane materials and membrane flux.
The degree of customization of adsorbents and high technical barriers
The adsorption material has a high degree of customization, and the adsorption capacity and dissolution loss rate are the core indicators to measure the efficiency of lithium extraction adsorbents.
The principle of adsorption and separation is mainly that adsorption occurs between the adsorbent and the adsorbate through intermolecular attraction (physical adsorption) or chemical interaction to generate chemical bonds (chemisorption). This process has a wide range of applications, and needs to customize the development of special adsorption materials according to needs, as is the case for lithium extraction from salt lakes.
Adsorption capacity (the maximum amount of adsorbed material per unit of adsorbent, which is related to the surface area and pore size of the adsorbent), cycle life (the degree of loss of the adsorbent, usually measured by the dissolution loss rate), etc. are the core indicators to measure the efficiency of lithium extraction adsorbents. In the extraction of lithium from salt lakes, it is necessary to develop adsorbents with large adsorption capacity, low dissolution loss rate and strong selectivity.
At present, there are three main technical routes for lithium extraction adsorbents from salt lakes:
- Aluminum-based adsorbents: widely used in chloride-type and magnesium-sulfate subtype salt lakes, with fast adsorption rate, no acid consumption in the desorption process, and relatively low cycle stability.
- Titanium-based adsorbent: suitable for alkaline salt lakes rich in hydroxide, and solves the problem of dissolution loss rate on the basis of manganese-based in carbonate salt lakes, it is currently in the pilot stage;
- Manganese-based adsorbents: suitable for alkaline salt lakes rich in hydroxide radicals, with large adsorption capacity but high dissolution loss rate, waste water needs to be treated in environmental protection, and the current industrialization process is hindered.
Membrane market
Membrane separation is one of the most environmentally friendly separation technologies. Membrane gradient coupling is commonly used in salt lakes. The difficulty of the process lies in the strength of membrane materials and membrane flux. The essence of membrane separation is a physical method, that is, the separation of different substances is achieved by pressure and the pore size of the membrane. The core is the selection of membrane materials.
Since no additional reagents are required in the process, membrane separation is one of the most environmentally friendly techniques. For the separation of magnesium and lithium in lithium extraction from salt lakes, organic membranes with smaller pore sizes are often selected, and gradient coupling of membranes (reverse osmosis, nanofiltration membranes, ultrafiltration, etc.) is often used. The technical difficulties of this process section lie in the strength of membrane materials, membrane permeability amount, etc.
The replacement of nanofiltration and reverse osmosis membranes has begun, and attention is paid to enterprises with self-developed advantages.
- Reverse osmosis membrane market: At present, major Chinese reverse osmosis membrane companies include Wharton Technology, Visaibo, Sanda Membrane, etc.
- Nanofiltration membrane market: According to data, the sales of China’s nanofiltration membrane market in 2019 was 600 million RMB. At present, China’s nanofiltration membrane market is mainly occupied by other countries, and the market share of Chinese manufacturers is relatively small.
Enterprises with technical advantages in lithium extraction process package design
Jiuwu Hi-Tech: Ceramic membrane and organic membrane covering the whole line, mastering a variety of core technologies of adsorbents
It is the leader of ceramic membranes in China, and its multi-field expansion is steadily advancing. In terms of adsorbent materials, it has successfully developed aluminum-based and titanium-based lithium adsorbent materials and proposed the “adsorption + membrane” method of raw halogen extraction process. It is expected to form an industrialized production capacity of about 2,000 tons per year this year.
Jiuwu Hi-Tech and Zijin Mining will accelerate the development of lithium extraction from salt lakes, and will provide adsorption materials, lithium extraction processes and process packages for Zijin Mining’s lithium salt lake resource projects, lithium resource deep processing projects, mine liquid treatment and metal resource utilization, and industrial water treatment projects.
In addition, Jinhai Lithium has deployed CO to fuel ethanol, titanium dioxide clean production and other emerging downstream, and there is great potential for expansion in many fields. In addition to the deployment of lithium extraction from salt lakes, the company has added new downstream applications such as CO to fuel ethanol and clean production of titanium dioxide.
Lanxiao Technology: Pioneer of lithium extraction adsorbent in salt lake, with 40,000 tons/year adsorbent capacity.
It is the leader of adsorbents in China, and the net profit attributable to the parent in the first three quarters of 2022 increased by 32% year-on-year. The company is mainly engaged in ion exchange adsorption resins and related supporting system devices, and currently has a capacity of 40,000 tons/year of adsorbents.
It has rich experience in the industrialization of lithium extraction from salt lakes. Relying on the technology of lithium extraction by adsorption and separation, the company has successfully provided solutions for lithium extraction from salt lake brine for several projects and realized industrialized operations.
Since the second half of 2021, the company has signed orders for a number of large-scale salt lake lithium extraction projects. Since 2018, the cumulative contracted order production capacity has reached 68,600 tons/year of lithium carbonate + 10,000 tons/year of lithium hydroxide, providing adsorption equipment and installation construction.
Lithium carbonate is popular in battery industry, and there are more and more manufacturers develop lithium carbonate battery. Thus, here is an article of top 5 lithium carbonate factories in China for your reference.
Weisaibo: China’s leading membrane technology, self-developed salt lake lithium extraction nanofiltration membrane has excellent performance.
In 2019, it has deployed salt lakes to extract lithium, and its self-developed high-pressure nanofiltration membrane has excellent performance. At present, for lithium extraction from salt lakes, the company is continuing to develop high-pressure nanofiltration membranes. The performance has been stable in several salt lake lithium extraction experiments, and the removal rate (deboronation, decarbonation, and magnesium removal) has maintained a high level.
BEIJET: Won the bids for multiple battery-grade salt lake lithium extraction projects.
Relying on its rich experience in wastewater recycling, it has won bids for several battery-grade salt lake lithium extraction projects. Moreover, the company won the new bid for the 20,000-ton/year battery-grade monohydrate lithium hydroxide project in Lagocuo Salt Lake Lithium Mine in Aligaize County, Tibet, using the continuous adsorption method + membrane method + electrodialysis process route to provide it with a membrane treatment system.
Sanda Membrane: Battery-grade salt lake lithium extraction project landed.
It is a pioneer in China’s industrial membrane separation process, and constantly develops membrane applications. The company’s main business is water investment and operation and the application of membrane technology, of which membranes are mainly used in industrial separation, membrane water treatment, environmental engineering and other fields.
As a leader in membrane technology, the company can be used to extract lithium from salt lakes through the combination of self-developed ceramic membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes and other technologies.
Wharton Technology: Pioneer of import replacement of reverse osmosis membrane.
The company is in a leading position in the field of reverse osmosis membranes, with a market share of nearly 30% for four-inch membranes. In terms of industrial film, the company has a market share of 9% in the eight-inch film market, ranking among the top five, and ranks first in the four-inch film market with a market share of 29%.
In the same period, the sales volume of household film market accounted for 24%, ranking first in China. The company’s membrane separation technology and products have been maturely used in the field of lithium extraction from salt lakes.
