Lithium hydroxide production process and cost analysis per ton

Lithium hydroxide production process and cost analysis per ton
As the world’s largest production and sales base for power batteries and new energy vehicles, China’s development of new energy vehicles has greatly promoted the consumer demand for upstream raw materials, including basic lithium salts such as lithium hydroxide. Due to its low melting point and inherent chemical properties, lithium hydroxide can increase the stability of high-nickel ternary materials after application. According to the current production status of lithium hydroxide, this paper introduces the production process of lithium hydroxide, and analyzes the cost composition of lithium hydroxide in combination with the market, and provides reference for the production of lithium hydroxide in China.
​Lithium products have a very important position in modern industry, and are widely used in new energy and new materials fields such as battery industry, aluminum industry, grease, medicine, refrigerants, nuclear industry and photoelectric industry. With the progress of technology, the application range of lithium products continues to expand, the demand maintains rapid growth, and the development prospects of the industry are very broad. The continuous growth of the new energy vehicle market has driven the growth of the power battery industry [1]. In view of the persistent pursuit of high driving range and lightweight vehicles on the demand side, the trend of high nickelization has remained firm for a long time. Under the trend of high nickelization of power batteries, the demand for lithium salt is gradually changing from lithium carbonate to lithium hydroxide, and lithium hydroxide will replace lithium carbonate or become a trend. High energy density of high nickel ternary must use lithium hydroxide, with the development of high nickel ternary anode materials continues to accelerate, high nickel ternary materials in the power battery to achieve large-scale application, lithium hydroxide demand will continue to rise, lithium hydroxide and its preparation industry by the industry’s wide attention.

​Lithium hydroxide production cost analysis
​The main raw and auxiliary materials used in the production of lithium hydroxide are spodumene concentrate, sulfuric acid, soda ash, caustic soda, calcium carbonate, etc. There are two main aspects of energy consumption in the production process: one is the power consumption of equipment operation; Second, heat consumption in the production process. In this paper, according to the consumption of raw and auxiliary materials, energy consumption and lithium recovery rate of major domestic lithium hydroxide enterprises, the cost of raw materials occupies about 80% of the direct cost of lithium hydroxide, and then we can know the importance of upstream lithium resources for enterprise cost control.
​​Cost control is one of the core of the comprehensive competition of lithium chemical enterprises, and it is also a performance index that reflects the internal management mechanism and operation effect of enterprises. Enterprises can control costs by investing in lithium resources and obtaining stable and high-quality lithium raw materials; It can also improve product quality and reduce unit product cost through continuous improvement and innovation of various production processes, equipment and technologies. It can also increase research and development investment for technology project research and development and industrialization of scientific research results, increase the premium ability of high-end products through product differentiation strategy, ensure cost efficiency and improve the overall profitability.
Lithium hydroxide production status
​​​In 2019, lithium hydroxide became the main growth driver for lithium compounds due to the rapid development of high-nickel ternary batteries. According to the research report of Minmetals Securities, the global production and sales of single-water lithium hydroxide in 2019 was about 99,600 tons, and the demand was about 79,700 tons, of which the demand for lithium-ion batteries was about 62,000 tons. It is expected that the total global demand for lithium hydroxide will increase significantly to 566,000 tons in 2025, with a compound average annual growth rate of about 38.65% from 2019 to 2025, and the demand for lithium hydroxide for lithium batteries in 2022 is expected to exceed lithium carbonate.
​At present, the global high-quality lithium hydroxide production capacity is concentrated in China, with the acceleration of Tesla localization, as well as the power of BMW, NIO and other high-nickel models, China’s battery grade lithium hydroxide demand and production will have significant growth in 2020. At present, the raw material source of lithium hydroxide in China is more single than that of lithium carbonate, mainly using spodumene concentrate as raw material, and the concentration of manufacturers is higher.
​Lithium hydroxide production technology
​Ore, salt lake production of lithium hydroxide process path mature, but in the actual production, the production of high-quality lithium hydroxide products is not simple, especially the process of impurity removal threshold is high, downstream customers usually have differentiated index requirements, which is doomed to lithium hydroxide, especially battery grade lithium hydroxide difficult to become a standardized commodity. The ore can be a step production of battery grade lithium hydroxide, the first use of lithium concentrate roasting, acidification to produce lithium sulfate solution, and then lithium sulfate through sodium hydroxide conversion, filtration, evaporation concentration, crystallization (some using multiple crystallization), drying and other processes to produce battery grade lithium hydroxide; The mature process of salt lake is to first produce lithium carbonate and then causticize the production of lithium hydroxide. Although lithium extraction in Salt lake is rich in resources, due to the high impurity content of lithium extraction in Salt lake itself, and the universality of technology, plus lithium extraction enterprises in Salt Lake tend to sell high-quality lithium carbonate products directly, and use industrial grade (or sub-optimal) lithium carbonate as raw materials for the production of back-end lithium hydroxide. This will lead to its lithium hydroxide product quality, consistency is difficult to be guaranteed; Salt lake lithium extraction enterprises are also actively testing the process of producing lithium hydroxide by brine electrolysis, but in mass production, its process maturity and product quality still need to be observed and verified.
​The commonly used production methods of extracting lithium from ore to produce lithium hydroxide mainly include lithium carbonate and calcium hydroxide, calcination, lithium sulfate and so on. The production process of lithium carbonate and calcium hydroxide can obtain a solution with a concentration of about 3.5%. If the concentration is higher than this, the solubility of lithium carbonate will decrease due to the presence of lithium hydroxide and will be lost in the calcium carbonate residue. The disadvantage of calcining method is that the use of magnesium makes the process complicated, the equipment is seriously corroded, the evaporation water is large, and the energy consumption is high. Lithium sulfate production lithium hydroxide recovery rate is higher, can be continuous production, and can achieve automatic control, product performance is stable, low production cost, is the main production method in China.
​Lithium sulfate process takes natural lithium concentrate (α type) as raw material, first through rotary kiln roasting to transform α-lithium concentrate into β-lithium concentrate which is easy to react with sulfuric acid, then through sulfuric acid method to extract lithium in lithium concentrate, add water pulping leach, make solid lithium sulfate into liquid, add lime powder and calcium carbonate to adjust pH value. Impurities such as iron, calcium and magnesium are filtered out, and then calcium is further removed by adding sodium carbonate and ion exchange, and the lithium sulfate leaching solution is properly evaporated and concentrated. After adding sodium hydroxide, sodium sulfate decahydrate is separated by cooling to -5℃ ~ -15℃, and the separated mother solution is evaporated and concentrated to crystallize crude lithium hydroxide. Finally, the fine monohydrate lithium hydroxide was obtained by recrystallization.
​The basic principle is to use the solubility of Na2SO4 and LiOH at low temperature is different, and Na2SO4 is separated at low temperature to achieve the purpose of purifying liquid. The main reaction equations are as follows:
​α-Li2OAl2O34SiO2→ β-Li2OAl2O34SiO2
​Li2OAl2O34SiO2+H2SO4→ Li2SO4+H2OAl2O34SiO2
​Li2SO4+2NaOH+10H2O→ 2LiOH+Na2SO410H2O
​Conclusion
​Based on the production situation of lithium hydroxide, the main process and cost analysis of lithium hydroxide production are introduced. With the continuous improvement of the market’s requirements for the endurance and driving range of new energy vehicles, the requirements for the energy density of the power battery are also getting higher and higher, and the high nickelization three-way route has gradually become the common choice of mainstream car companies. The growth of demand for high nickel ternary materials will directly drive the growth of demand for lithium hydroxide, enterprises must continue to adhere to cost reduction and efficiency, constantly reduce product costs, improve product quality, the specific performance is: In resources, capital, personnel, production lines, sales and technology, investment and other aspects of the international strategic layout, while adhering to close to the market, to guide the sustainable, healthy and stable development of the market; Adhere to high-end, differentiated product orientation, continue to optimize the production process, and strive to improve product quality; Adhere to the focus on the direction of cutting-edge industry technology, constantly tap the capacity potential of existing production lines, accelerate the independent research and development and reserve of new technologies, new equipment and new processes, and realize the transformation from simple lithium processing and manufacturing business to lithium resource reserve, development and trade as well as lithium series product processing, the industrial chain extends upward and downstream, and the value chain climbs to the high-end. Our core competitiveness has been further enhanced.