Increased demand for lithium batteries to drive the development of technology

Continuous development of processes and equipment

A side-effect of growing demand for lithium is the tendency for mining companies to rush to list. "In the next few years, some companies will extract lithium carbonate online from lithium pyroxene ore. Its weight is usually about 8 <UNK> Li2O. To meet demand, it is easy to start," Jenike & Johanson(Tyngsboro, Mass; Project engineer Josh Marion at www.jenike.com. This impact, combined with the high value of lithium and its specific physical properties, emphasizes the importance of proper design at all stages of lithium processing-from the initial mining to the final refining step. When trying to achieve an ideal base of product purity, granularity and density, this forces the processor to approach bulk solids in new ways. "Many processing requirements may be more like pharmaceutical production than traditional mineral processing. There are high requirements for the material quality of battery manufacturers. If there is no reliable solid treatment, the required product consistency can not be achieved, "Marion explained.

Some of the major operational problems experienced by lithium processors include agglomeration, accumulation, and traffic stoppage. In order to extract lithium from lithium pyroxene ore after mining, the ore needs to go through a series of crushing and granularity grading steps to generate the desired granularity ore. The concentrate is then sent to the enrichment plant, where it is dried, ground, separated, dehydrated, and further grained steps to produce a lithium pyroxene concentrate. The concentrate then enters the processing plant for calcination, adding various aqueous solutions, acids, and other chemicals to extract different impurities such as iron, aluminum, Silicon, and magnesium. Finally, the wet filter cake is crystallized and dried into lithium hydroxide(LiOH) or lithium carbonate(Li2CO3) products. "Especially in the process of lithium in wet filter cake, if you do not have enough dryers or the processing equipment is not designed to handle slightly moist materials, then you usually accumulate lithium and lithium blocks throughout the factory. And because of the hygroscopicity of lithium salts, even when the material is dry, it may absorb moisture and cake, "Marion said. He stressed that attention to detail during the equipment design phase was essential to avoid these bottlenecks and ensure consistency in product quality. "When selecting and designing equipment, it is important to ensure that the material characteristics of each stage of the process are considered," he added.

With the development of LIB performance requirements, equipment manufacturers are developing new technologies to meet these requirements. "Now, the key parameters for lithium producers are purity and granularity," GEAGroupAG(Dusseldorf, Germany; Ananta Islam, director of sales at North American Chemicals, www.gea.com. The presence of certain impurities directly affects the performance of the battery, so lithium manufacturers must follow a strict purity standard. "Users are looking for very low levels of sodium, potassium, sulphur and heavy metals in battery-grade products," explains ChristianMelches, senior sales and technology manager at GEA. Whether starting from common saltwater materials in South America or typical lithium-lithium pyroxene ores in Canada and Australia, these impurities are usually present in considerable quantities. In order to solve the purity problem, the GEA provides a crystallization unit(Figure 1) that can be used in combination to optimize purification. "The edge comes from knowing how to guide the process through the process itself to a few crystallizers to get the purest product," he said. Another important consideration for combined crystallization devices is energy efficiency. One energy-saving measure is the use of mechanical re-compression of mould steam to produce steam used to drive the process.

LiOH-The preferred form of lithium for most current LIB manufacturers-requires an extremely precise particle size distribution, which requires a dedicated spray drying device. Islam explained that the typical particle size range of traditional spray drying may be 40-50 μm, but for LiOH processing, the range is approximately 5-7 μm. To ensure that the material meets requirements, GEA develops and patents specific nozzles for lithium processing(Figure 2). "Combi-Nozzle uses high pressure nozzles and compressed air for secondary atomization to further reduce particle size," Islam said. Lithium manufacturers said that the correct compaction of the powder requires less granularity, which directly affects the performance of the LIB. According to Islam, this special nozzle was developed based on the technology used by the pharmaceutical industry for spray drying particles, which are used for inhalable drugs that require very small particles.

Although salt water and lithium pyroxene produce most of today's lithium, in the coming years, due to high demand, other sources may be generated. "Mining companies are beginning to invest in replacing lithium sources, so future processing equipment may need to be adjusted to handle more impure raw materials," Melches said.

In order to increase resource utilization and reduce LIB costs, technologies are emerging to introduce more raw material flexibility for different lithium preparations and lower raw materials. NanoOne Materials Inc.(Vancouver, British Columbia, Canada; www.nanoone.ca) has developed a proprietary process for the manufacture of cathode materials for various chemical batteries. Table 1 lists the most common LIB chemicals on the market, such as NMC, NCA and LTO. Unlike typical solid-state cathode production techniques, NanoOne's technology is solution-based. "The solution-based process allows us to make battery materials more cheaply, and the process is very flexible, so it can be used to make multiple formulations of lithium cathode materials," said Stephen Campbell, chief scientist of NanoOneMaterials. And ... As battery manufacturers try to optimize LIB capacity, stability, and cost, they try to reduce cobalt content while increasing cathode nickel content. In order to make these high-nickel materials, LiOH is the preferred lithium raw material, but it has become more and more difficult and expensive to obtain. NanoOne's technology can use LiOH or more abundant and inexpensive Li2CO3 to manufacture cathode materials, providing Li2CO3 manufacturers with a more direct approach, thus avoiding the investment in expensive processes to convert Li2CO3 to lithium hydroxide. "We can relax the supply chain by using lithium sources that no one else can use," Campbell said.

NanoOne's solution technology dissolves lithium in water(under environmental conditions) with other transition metals, so the type of lithium is independent-LiOH and Li2CO3 are treated in the same way. The dissolved metal is precipitated to produce a crystal precursor with an ordered lattice structure of all existing cathode metals. Campbell said that this orderly structure helps launch faster in the furnace. "We can launch the material within seven hours because the metal has been mixed in an orderly manner. The traditional method of grinding lithium with other metals requires long-distance diffusion, which may take 1 to 2 days to complete, he added. Another advantage of NanoOne's technology is that crystal uniformity can dilute impurities, making the process more tolerant of low-grade raw materials, thus further reducing operating costs. NanoOne is currently testing lithium samples of different purity to assess the technology's ability to deal with various contaminated species. "We see that the effects of certain impurities are not as bad as some people think. For example, magnesium can be used as a adulterant and can actually improve performance, "Campbell explains." NanoOne is currently able to produce cathode materials in 300 kg batches at a pilot plant with a capacity of up to 1 ton per day. The team recently began sending product samples to third-party organizations for validation.

Battery recovery

Used batteries have a staggering amount of high-demand material, and many organizations are working to develop efficient recycling technologies to take full advantage of this untapped resource. The United States Manganese Corporation has developed a process for recovering cathode metals(including lithium, cobalt, manganese, nickel and aluminum) from EV batteries(Figure 3). LarryReaugh, president and chief executive officer of AY, said the company was currently building a kg-sized pilot plant to demonstrate the technology, using a proven continuous process to recover manganese from low-grade ores(Figure 4). A 3 ton / day commercial plant is under construction and will utilize scrap or substandard metals from LIB producers. In laboratory tests, 100 tins of cathode metal were recovered from LIB materials and waste, which is usually eventually carried out in landfills or smelters. Metal recovery is not efficient and it is not even possible to recover lithium from any cathode. Reaugh explained that the AY process should be easy to scale because it proves the history of continuous operation when the level of manganese production is high.

Using sulfur dioxide and other low-cost reagents, as well as automatic battery dismantling processes, AMY's recovery technology is almost free of waste because 100 tons of metal is recovered and process water is recycled. Reaugh said that the revolutionary part of hydro metallurgical processes simplifies precipitation steps, increases metal yields, and has the flexibility to work with many metals and cathode chemicals.

Considering the future supply and demand of battery materials such as lithium and cobalt, Reaugh believes that when comparing the recycling process with mining, its advantages are very obvious. "Cobalt prices are going through the roof, and there doesn't seem to be any immediate production coming up, and for new mines, you need to consider years and years of delivery time," he added. "I think our recycling is more economical than mining. "

Engineers at the University of California, San Diego(www.ucsd.edu) have developed another new technology for recovering cathode materials from discarded LIBs. The process begins with the non-destructive particle separation step, involving the dissolution, suspension, filtration and washing of adhesives, followed by the treatment of hydro thermal lithification, in which cathode particles are pressurized in alkaline solutions in the presence of lithium salts. The subsequent annealing steps help correct the crystalline structure of the material, which could degenerate during previous battery use, explains zhengchen, a professor of NanoEngineering at the University of California, San Diego. According to the team, the recovered battery material recovered during the process recovered to its original performance in terms of charge storage capacity, charging time and battery life.

Chen said one of the main benefits of this process is its energy efficiency compared to other battery recycling technologies. "We do not destroy most of the particle structure and composition, which consumes a lot of energy to recreate. "Avoiding repetition of these manufacturing steps can help save energy," he said. This process has been demonstrated on a gram scale and has been proven to be available for LCO and NMC batteries, allowing them to flexibly handle LIBs from electric vehicles and consumer electronics.

Metals in fossil fuel processing

Growing global demand for LIBs has forced the industry to consider alternative energy sources for many metals and, in some cases, to seek inspiration from traditional oil and gas processes. MGX Minerals Inc. and Highbury Energy Inc.. A new technology developed in cooperation with Vancouver aims to recover metals(Coke) used in LIBs from petroleum Coke, the main by-product of petroleum refining. Petroleum Coke is sent to advanced thermochemical gasification processes to produce hydrogen and ash by-products from which high-priced metals, including nickel and cobalt, and various concentrations of rare earth elements are recovered. The high demand for hydrogen and the large amount of cheap petroleum Coke raw materials make this project very attractive. The key to the effectiveness of metal recovery lies in the accuracy of the gasification fluidized bed reactor technology to eliminate the accumulation of tar and residues that usually affect the gasification operation. "This process requires low-tar gasification and clean ash by-products. The last thing we want is tar or organic material in ash, which can make metal processing quite difficult, "explained Jared Lazerson, president and chief executive officer of MGX Mining. Another advantage of this gasification process is that it can handle a very wide range of particle sizes, including very fine materials. Since the gasifier acts as a centrator, the metal recovery process is relatively simple.

According to Lazerson, the ability to co-locate the oil gasification and metal recovery processes with the oil sands processing site eliminates logistics and transport problems. Highbury energy has used its proprietary fluidized bed reactor technology to run gasification test plants for years. "We're just beginning to figure out whether the next stage is going to be a pilot or a small commercial plant," Lazerson said. "In addition to petroleum Coke, other projects have proposed coal as a source of asphalt.

In lithium, MGX Minerals is advancing nanofiltration technology for lithium recovery. In this process, the patented high-intensity flotation process uses microbubbles to remove residual oil, metals and small particles from the raw material-usually saline, tailings or lithium containing wastewater from oil and natural gas or chemical processing sites. Lazerson said that this step can remove 99 tons of physical particles, provide a very clean source of salt for the nanofiltration step, and then further refine the lithium liquid flow to the purity level required for LIB manufacturing. "Basically, it's a highly specialized adsorption technique for nanites," he added. "We remove impurities such as sodium, magnesium and calcium in the first step, so what we end up with is very pure lithium concentrate, as well as other salt concentrates that can be monetized," Lazerson notes. The company is about to complete its first commercial plant and is evaluating the installation location of the next plant. The plant currently produces 750 barrels per day and initial construction work is under way, producing 7,500 barrels per day. MGX Mining also works with partners in South and North America, including potential deployment of large-scale natural brine sites associated with geothermal treatment in Southern California. The company also recently announced a joint development project with Orion Laboratory Co. Ltd. and Light Metals International to commercialize a new modular thermochemical process to produce high-purity Li2CO3 or LiOH in lithium pyroxene concentrate.

Another potential source of lithium is wastewater from fracking activities. University of Texas at Austin(UT; www.utexas.edu) with the University of Monash, Melbourne, Australia(Melbourne, Australia, www.monash.edu) and CSIRO(Melbourne, Australia); www.csiro.au) developed a membrane process using metal organic skeletons(MOFs) to selectively extract lithium from wastewater(Figure 5). "Considering that the specific MOF of this work has an aperture, can it accommodate? What? Nan-partially dehydrated lithium ions, but not large ions or high hydrated ions, make them selective for lithium relative to larger parts of dehydrated ions such as sodium, potassium, and cesium, "UT's professor of chemical engineering, Benny Freeman explained. "Our current assumption is that lithium ions are partially dehydrated into MOF pores, where they are transmitted very rapidly through the nanocrystalline gaps in MOF crystals. This mechanism means that the MOF's internal interaction with lithium ions is favorable, resulting in at least partial dehydration of ions, "Freeman added. Currently, MOF membranes have been demonstrated on a laboratory scale, but the UT Group is working to adapt this technology to the continuous flow process established by CSIRO to produce a larger number of MOFs. The team believes that the technology is not limited to lithium, MOF can be used for desalination purposes, or adjusted to selectively penetrate monovalent anions, such as removing fluoride from drinking water or removing nitrate from agricultural runoff. For more information about the application of membranes in litihum recovery, see the coverage of expanded membranes in CPI.

Purchase of cobalt closer to home

The increase in the manufacturing capacity of LIB has brought unique pressure on the supply of cobalt. Cobalt is mined not only in politically unstable areas, but also primarily as a by-product of nickel and copper mines, so its economy is closely related to the needs of these markets. Recognizing the need for new major cobalt to meet the demand, Fortune MinimalsLtd.. (London, Ontario, Canada; www.fortunemanerals.com) is carrying out an extensive cobalt project in North America, which produces very little cobalt. The Fortune Mines project includes cobalt, gold, bismuth and copper mining in a large deposit in the Northwest Territories of Canada, as well as a processing metal refinery in Saskatchewan that will process metal concentrates from mines. "The project is basically mitigating supply chain risks by having a vertically integrated supply chain transparency source in North America," explains Robin Goad, president and chief executive officer of Fortune Mines. The project has undertaken feasibility and front-end engineering(FEED) studies, and the group is currently completing a new feasibility study to consider productivity gains of 30 per cent. Goad said: "Our goal is to produce about 7,000 tons of cobalt sulfate heptahydrate each year, which is the preferred material for NCA and NMC batteries in the automotive industry.

The Saskatchewan plant will start processing metal concentrates in mines from bismuth. In a bismuth treatment device, the secondary flotation step produces a cobalt sulphide concentrate containing gold and then sends it to the cobalt treatment device(Fig. 6). Here, cobalt concentrate is immersed in high-pressure acid at 180 °C in a autoclave. "Cobalt sulfide dissolves into a solution in an exothermic reaction. Because sulphide minerals produce acid during dissolution, the acid is rarely consumed, "Goad explained. Next, gold is recovered and sent to a separate process unit, cobalt material is neutralized, and impurities-iron, copper, and the most critical arsenic-are precipitated to produce a relatively pure cobalt flow. "We remove arsenic impurities and use excess iron in the solution to convert it to iron arsenate. The arsenic, which was toxic, is now in a non-hazardous stable state and can be safely landfilled at the project site, "Goad added. This arsenic conversion step is particularly important for the plant to deal with metals from other mines, as many new cobalt production is arsenic-based and there are restrictions on the export of arsenic-containing compounds. Goad said: "In addition to processing concentrates from our own mines, we believe that refineries will be able to deal well with concentrates from other cobalt projects in North America. Fortune Mines expects the plant to start construction in early 2019. Debugging and commercial operations will take place in 2021. "The long-term business plan is to diversify into recycling, because we will have one that will be able to remove residues, scrap or scrap batteries and recycle metals," says Goad. He stressed the need to establish an infrastructure of collection points to support these waste streams before large-scale recycling could occur.

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