Understanding the future of lithium: Part 2, temporally and spatially resolved life‐cycle assessment modeling - Ambrose - 2020 - Journal of Industrial Ecology - Wiley Online Library --- 理解锂的未来：第2部分，时间和空间分辨寿命周期评估建模-安布罗斯-2020年-工业生态学杂志-Wiley在线图书馆
Abstract 摘要[color=var(--article-headings-color)]An array of emerging technologies, from electric vehicles to renewable energy systems, relies on large-format lithium ion batteries (LIBs). LIBs are a critical enabler of clean energy technologies commonly associated with air pollution and greenhouse gas mitigation strategies. However, LIBs require lithium, and expanding the supply of lithium requires new lithium production capacity, which, in turn, changes the environmental impacts associated with lithium production since different resource types and ore qualities will be exploited. A question of interest is whether this will lead to significant changes in the environmental impacts of primary lithium over time. Part one of this two-part article series describes the development of a novel resource production model that predicts future lithium demand and production characteristics (e.g., timing, location, and ore type). In this article, part two, the forecast is coupled with anticipatory life-cycle assessment (LCA) modeling to estimate the environmental impacts of producing battery-grade lithium carbonate equivalent (LCE) each year between 2018 and 2100.
一系列新兴技术，从电动汽车到可再生能源系统，都依赖于大型锂离子电池（LIBs）。LIBs是清洁能源技术的关键推动者，通常与空气污染和温室气体减排策略相关。然而，LIBs需要锂，扩大锂供应需要新的锂生产能力，这反过来会改变与锂生产相关的环境影响，因为将开采不同的资源类型和矿石品质。一个感兴趣的问题是，这是否会导致原生锂的环境影响在未来发生重大变化。本两部分文章系列的第一部分描述了一个新型资源生产模型的发展，该模型预测未来锂需求和生产特征（例如时间、地点和矿石类型）。在本文的第二部分中，预测与预见性生命周期评估（LCA）建模相结合，以估计2018年至2100年每年生产电池级碳酸锂当量（LCE）的环境影响。 [color=var(--article-headings-color)]The result is a normalized life-cycle impact intensity for LCE that reflects the changing resource type, quantity, and region of production. Sustained growth in lithium demands through 2100 necessitates extraction of lower grade resources and mineral deposits, especially after 2050. Despite the reliance on lower grade resources and differences in impact intensity for LCE production from each deposit, the LCA results show only small to modest increases in impact, for example, carbon intensity increases from 3.2 kg CO2e/kg LCE in 2020 to 3.3 kg CO2e/kg LCE in 2100.
结果是反映了LCE的生命周期影响强度的归一化值，反映了资源类型、数量和生产地区的变化。到2100年，锂需求的持续增长需要开采较低品位的资源和矿床，特别是在2050年之后。尽管依赖于较低品位的资源并且每个矿床的LCE生产影响强度存在差异，但生命周期评价结果显示，影响只有小到适度的增加，例如，碳强度从2020年的3.2千克CO2e/千克LCE增加到2100年的3.3千克CO2e/千克LCE。
1 INTRODUCTION 1. 介绍[color=var(--article-headings-color)] An array of emerging technologies, from electric vehicles (EVs) to renewable energy systems, relies on large-format lithium ion batteries (LIBs). Improving performance, increased production, and decreasing prices of large format LIBs has enabled remarkable growth in these clean energy applications. In response, global production capacity for LIBs is expected to triple in the next 5 years, exceeding 300 GWh by 2022 (Curry, [color=var(--article-body-links-color)]2017). This means that the constituent materials used in LIBs must be produced at increasing rates as well. By 2030, global demand for lithium in LIBs is expected to range from 300 to 600 thousand metric tons[color=var(--article-body-links-color)] [size=0.875]1 of lithium per year, comprising more than three quarters of total lithium demand.
新兴技术涵盖了从电动汽车（EVs）到可再生能源系统的一系列技术，都依赖于大型锂离子电池（LIBs）。大型锂离子电池的性能提升、产量增加和价格下降，使得清洁能源应用得以显著增长。预计全球LIBs的生产能力在未来5年内将增长至300GWh以上（Curry, 2017）。这意味着LIBs所使用的原材料也必须以增长的速度生产。到2030年，全球对LIBs中的锂的需求预计将达到每年30至60万公吨，占总锂需求的四分之三以上。 [color=var(--article-headings-color)] Two key issues for LIBs and emerging technologies that rely on lithium batteries are resource constraints and environmental impacts that occur during production. Growth in demand for LIBs across a number of sectors is already placing strains on current lithium production capabilities, and will likely move production to increasingly low-grade resources over time (Ambrose & Kendall, [color=var(--article-body-links-color)]2019; Helbig, Bradshaw, Wietschel, Thorenz, & Tuma, [color=var(--article-body-links-color)] 2018). It is unclear how the dynamics of supply and demand will affect the life-cycle environmental impacts of lithium, and thereby, the environmental impacts of technologies that rely on LIBs. Given the role of LIBs as an enabler of technologies associated with mitigating environmental impacts (e.g., electric vehicles and renewable electricity integration), the potential increase in impacts from lithium production are a concern.
锂离子电池（LIBs）和依赖锂电池的新兴技术面临的两个关键问题是资源限制和生产过程中的环境影响。各个领域对锂离子电池的需求增长已经对当前的锂生产能力造成了压力，并且随着时间的推移，可能会将生产转移到日益低品位的资源上。目前尚不清楚供需动态将如何影响锂的生命周期环境影响，从而影响依赖锂离子电池的技术的环境影响。考虑到锂离子电池在促进与减轻环境影响相关的技术（例如电动汽车和可再生电力整合）方面的作用，锂生产可能带来的影响潜在地令人担忧。 [color=var(--article-headings-color)] This article is the second in a two-part series. Part one (Ambrose & Kendall, [color=var(--article-body-links-color)]2019) developed a forecast of lithium demand and coupled it with a spatially resolved resource model to predict, at the resolution of identified deposits, the primary lithium resource production over time from 2018 to 2100. Part two uses the results presented in part one to develop a temporally and spatially resolved life-cycle assessment (LCA) of lithium that reflects the changing sources of lithium expected to be dispatched over time.
本文是两篇系列文章中的第二篇。第一部分（Ambrose & Kendall, 2019）制定了锂需求预测，并将其与空间分辨率资源模型相结合，以预测从2018年到2100年期间，以已识别矿床的分辨率为主要锂资源生产。第二部分利用第一部分呈现的结果，开发了一个随时间和空间变化的锂生命周期评估（LCA），反映了预计随时间推移而分派的锂的变化来源。
1.1 关于LIB需求、锂供应和锂生产环境影响的先前研究[color=var(--article-headings-color)] LIB demand is fueled in part by the falling price of LIBs; cost targets for LIBs set 10 and 15 years ago have already been met and exceeded; with costs now expected to fall below $80/kWh, enabling economic deployment in an increasing range of applications (Curry, [color=var(--article-body-links-color)]2017; Nykvist & Nilsson, [color=var(--article-body-links-color)] 2015; U. S. Department of Energy, [color=var(--article-body-links-color)] 2017). Falling prices for LIBs are not a consequence of falling lithium prices. In fact, demand for lithium for use in LIBs is likely insensitive to increases in the price of lithium (Ciez & Whitacre, [color=var(--article-body-links-color)] 2016) because, despite their name, the actual content of lithium in LIBs is low, and relative to other costs in manufacturing, lithium costs are not large. Thus, significant increases in the price of battery-grade lithium carbonate may not slow adoption of LIBs and, thus, demand for LIBs.
LIB需求在一定程度上受到LIB价格下降的推动；设定在10年和15年前的LIB成本目标已经得到满足并超过；预计成本现在将下降至每千瓦时不到80美元，从而在越来越多的应用中实现经济部署（Curry, 2017; Nykvist & Nilsson, 2015; 美国能源部, 2017）。LIB价格下降并非是锂价格下降的结果。事实上，用于LIB的锂需求可能对锂价格上涨不敏感（Ciez & Whitacre, 2016），因为尽管名字中含有锂，但LIB中实际的锂含量很低，而且相对于制造中的其他成本，锂成本并不大。因此，电池级碳酸锂价格的显著上涨可能不会减缓LIB的采用速度，从而也不会减少LIB的需求。 [color=var(--article-headings-color)] Recent growth in the demand for critical energy materials, which includes lithium, is a concern for climate mitigation efforts and local environmental impacts (Bauer et al., [color=var(--article-body-links-color)]2010; Department of Interior, [color=var(--article-body-links-color)] 2018). Previous studies have investigated the effects of increasing demand and decreasing resource quality on the environmental impacts of metal production. For example, production of copper has shifted to increasingly low- grade resources with lower yields over the last century (Crowson, [color=var(--article-body-links-color)] 2012; Memary, Giurco, Mudd, & Mason, [color=var(--article-body-links-color)] 2012). Studies have indicated the significant decrease in the average copper ore grade, from greater than 12% Cu to less than 1% Cu by mass, has been accompanied by an order of magnitude increase in energy required for mining and beneficiation (Northey, Mohr, Mudd, Weng, & Giurco, [color=var(--article-body-links-color)] 2014). The grade of the deposit affects the design of the mine and processing facilities, as well as overburden, effluent and tailings generated, all of which influence the LCA of metals production (Durucan, Korre, & Munoz-Melendez, [color=var(--article-body-links-color)] 2006). Average ore grade has been proposed as a characterization factor for comparing the life-cycle environmental impacts of metal extraction (Vieira, Goedkoop, Storm, & Huijbregts, [color=var(--article-body-links-color)] 2012). Coupled with continued growth in demand for copper, these trends could result in a doubling of the climate impacts associated with the global copper cycle by 2050 (Kuipers, van Oers, Verboon, & van der Voet, [color=var(--article-body-links-color)] 2018).
近年来对关键能源材料的需求增长，包括锂，对气候缓解努力和当地环境影响构成了关注（Bauer等，2010年；内政部，2018年）。先前的研究已经调查了需求增加和资源质量下降对金属生产环境影响的影响。例如，铜的生产在过去一个世纪已经转向了产量逐渐降低的低品位资源（Crowson，2012年；Memary，Giurco，Mudd和Mason，2012年）。研究表明，铜矿石平均品位显著下降，从大于12%的Cu降至不到1%的Cu（按质量计算），伴随着采矿和选矿所需能量增加了一个数量级（Northey，Mohr，Mudd，Weng和Giurco，2014年）。矿床的品位影响了矿山和加工设施的设计，以及产生的覆土、废水和尾矿，所有这些都影响了金属生产的生命周期评价（Durucan，Korre和Munoz-Melendez，2006年）。 平均矿石品位已被提议作为比较金属提取生命周期环境影响的表征因子（Vieira, Goedkoop, Storm, & Huijbregts, 2012）。伴随对铜需求的持续增长，这些趋势可能导致到2050年全球铜循环所关联的气候影响翻倍（Kuipers, van Oers, Verboon, & van der Voet, 2018）。 [color=var(--article-headings-color)] While several studies have considered the environmental impacts of lithium used in cathode materials and batteries (Grosjean, Miranda, Perrin, & Poggi, [color=var(--article-body-links-color)]2012; Li, Gao, Li, & Yuan, [color=var(--article-body-links-color)] 2014; Notter et al., [color=var(--article-body-links-color)] 2010; Speirs, Contestabile, Houari, & Gross, [color=var(--article-body-links-color)] 2014; Swart, Dewulf, & Biernaux, [color=var(--article-body-links-color)] 2014; Yu et al., [color=var(--article-body-links-color)] 2014), only one study has considered potential variability in impacts resulting from the different resources that can supply lithium. Stamp, Lang, and Wäger ([color=var(--article-body-links-color)] 2012) modeled the production of lithium carbonate from generic brine and rock (i.e., pegmatite) sources, and considered potential implications for the environmental impacts of LIBs. They found that carbonate from rock deposits generally have higher impacts than those from brine production, but that heating brines to accelerate the removal of water can quickly increase energy inputs and, thus, emissions related to lithium production (Stamp et al., [color=var(--article-body-links-color)] 2012).
虽然已有几项研究考虑了锂在正极材料和电池中的环境影响（Grosjean, Miranda, Perrin, & Poggi, 2012; Li, Gao, Li, & Yuan, 2014; Notter et al., 2010; Speirs, Contestabile, Houari, & Gross, 2014; Swart, Dewulf, & Biernaux, 2014; Yu et al., 2014），但只有一项研究考虑了不同资源供应锂可能导致的影响变化。Stamp, Lang, 和 Wäger (2012) 对从普通卤水和岩石（即伟晶岩）来源生产碳酸锂进行了建模，并考虑了对LIBs环境影响的潜在影响。他们发现，岩石沉积物中的碳酸盐通常比卤水生产的碳酸盐具有更高的影响，但加热卤水以加速去除水分可能会迅速增加能源投入，从而增加与锂生产相关的排放（Stamp et al., 2012）。 [color=var(--article-headings-color)]While previous studies focused on issues and dynamics of lithium supply and demand with respect to the rapidly increasing demand for LIBs, no studies combined this modeling with quantitative assessment of environmental impacts from lithium production at different sites and from different resources. Thus, the relationship between the environmental intensity of lithium production and increasing demand over time has not been previously explored. In addition, the projections of LIB demand for EVs have been highly variable across studies. Here, we investigate the temporal dynamics of environmental impacts of lithium carbonate used for LIBs in the context of increasing demand and the need for expansion of production to new sites.
之前的研究主要关注锂供需动态与锂电池快速增长需求之间的问题，但没有将这种建模与不同地点和资源的锂生产环境影响的定量评估结合起来。因此，锂生产的环境强度与随时间增长的需求之间的关系尚未被探索。此外，关于电动汽车锂电池需求的预测在不同研究中差异很大。在这里，我们研究了用于锂电池的碳酸锂的环境影响的时间动态，以及随着需求增长和扩大生产到新地点的需求。 [color=var(--article-headings-color)]To estimate environmental impacts dynamically, we undertook the following research steps (steps one and two were completed in part one of this article series, while step three was completed here in part two):
为了动态估计环境影响，我们进行了以下研究步骤（步骤一和步骤二已在本文系列的第一部分完成，而步骤三已在本文系列的第二部分完成）：[color=var(--article-headings-color)]Provide a novel forecast for demand for battery-grade lithium carbonate to 2100 based on capacity for lithium battery manufacturing.
根据锂电池制造能力，对2100年电池级碳酸锂需求提供新的预测。 [color=var(--article-headings-color)]Develop a resource model to link forecasted demand to global lithium resources, development of known reserves, and the relative costs of dispatching new lithium resources to yield estimates of lithium production over time differentiated by the source deposit, which determines location and ore type of source.
开发一个资源模型，将预测的需求与全球锂资源、已知储量的开发以及调度新的锂资源的相对成本联系起来，以估算随时间变化的锂生产量，根据资源矿床的来源确定位置和矿石类型。 [color=var(--article-headings-color)]Develop LCA models founded on regionalized background data and engineering-based models for mining and refining of different resource types and resource qualities to evaluate the effects of expanding the supply of lithium on the environmental impacts of lithium for the battery market.
基于区域化背景数据和基于工程的模型，开发LCA模型，用于评估扩大锂供应对电池市场锂的环境影响。
[color=var(--article-headings-color)] Two scenarios for lithium production, an optimistic (high demand) and a conservative (low demand) scenario, were developed. Under the optimistic forecast, demand continues to increase steadily after 2050, to 7.5 million t LCE per year in 2100. In the conservative scenario, global production increases from 237 thousand metric tons LCE in 2018, to 4.4 million metric tons LCE/year by 2100. The results of the resource model suggest that production from high-grade brines could be sufficient to satisfy the majority of demand through 2035, but sustained future demand will require the development of lower grade and unfavorable deposits (Ambrose & Kendall, [color=var(--article-body-links-color)]2019).
发展了锂生产的两种情景，一种是乐观的（高需求），另一种是保守的（低需求）。在乐观的预测下，需求在2050年后继续稳步增长，到2100年达到每年750万吨锂碳酸盐当量。在保守的情景下，全球产量从2018年的23.7万公吨锂碳酸盐当量增加到2100年的每年440万公吨锂碳酸盐当量。资源模型的结果表明，高品位卤水的产量可能足以满足大部分需求至2035年，但未来持续的需求将需要开发品位较低和不利的矿床（Ambrose & Kendall, 2019）。
本研究进行了一项时间动态的（考虑2018年至2100年间每年的时间步长）电池级碳酸锂的生命周期评价，以碳酸锂当量（LCE）为单位进行跟踪。生命周期评价的范围包括能源消耗、化学品、爆破和其他对空气和水的排放，但不包括土地转型和尾矿（例如，处理废料）的一些影响。还使用了区域能源清单数据来反映初级能源来源和转换技术的差异。该研究提供了一套新颖的碳酸锂生命周期清单（LCIs），用于大型LIBs（如电动汽车中使用的那些）。本研究对现有研究工作的贡献包括一些在先前研究中要么缺失要么被确定为需要额外研究的因素。其中包括：- Inclusion of demand for large format LIBs sectors other than light-duty passenger vehicles (i.e., heavy-duty vehicles and stationary applications).
除轻型乘用车之外，还包括大型LIBs领域的需求（例如重型车辆和固定应用）。 - Changes in production sources (i.e., expansion of existing sites and development of new deposits) over time.
生产来源的变化（即现有场地的扩建和新矿床的开发）随时间的推移。 - Variability in energy requirements and efficiency of lithium carbonate production across lithium deposits.
锂碳酸盐生产的能源需求和效率在不同锂矿床之间存在差异。 - Regional availability of primary energy sources and electricity generation technologies.
主要能源来源和发电技术的区域供应情况。
[color=var(--article-headings-color)] The methods used to develop the resource model are available in part one of this article series (Ambrose & Kendall [color=var(--article-body-links-color)]2019); here, we discuss the development of the LCA model.
资源模型开发所使用的方法在本文系列的第一部分中有详细介绍（Ambrose & Kendall 2019）；在这里，我们讨论生命周期评价模型的开发。
生命周期评估模型2.1.1 Goal and scope
2.1.1 目标和范围[color=var(--article-headings-color)] The goal of the LCA model is to estimate the life-cycle impacts for producing LCE from available primary resources. The scope of the LCA is from mine to processor or refining gate and reflects specific resource conditions (e.g., the concentration of lithium in the ore), and differences in background systems (namely national-level energy systems). The functional unit selected is 1 kg of battery grade LCE (≥99% Li2CO3 by content). Figure [color=var(--article-body-links-color)]1 provides a summary of the key processes and inputs included in the LCA model, and highlights the stages at which dynamic inventory modules have been developed to reflect local environmental conditions, regional availability of primary energy sources, electricity generation technology, and the effects of resource quality on material extraction, transportation, and refining processes. Future technological developments in production machinery or electricity generation (e.g., increased renewables deployment) were not included in the scope. Potential implications and limitations of these assumptions are briefly summarized in the discussion section.
LCA模型的目标是估算从可利用的初级资源生产LCE的生命周期影响。LCA的范围从矿山到加工或精炼门，反映了特定资源条件（例如矿石中的锂浓度）和背景系统的差异（即国家级能源系统）。所选的功能单位是1千克电池级LCE（≥99% Li2CO3含量）。图1总结了LCA模型中包括的关键过程和输入，并突出了已开发动态清单模块以反映当地环境条件、初级能源来源的区域可用性、电力发电技术以及资源质量对材料提取、运输和精炼过程的影响的阶段。生产机械或电力发电的未来技术发展（例如增加可再生能源部署）不在范围内。这些假设的潜在影响和局限性在讨论部分中简要总结。  Figure 1 图1[color=var(--article-body-links-color)]Open in figure viewer
在图像查看器中打开[color=var(--article-body-links-color)]PowerPoint
[size=0.75]Flows and processes included in the life-cycle assessment model
生命周期评估模型中包括的流程和过程
2.1.2 Life-cycle inventory model
生命周期清单模型[color=var(--article-headings-color)] The lithium production process can vary from deposit to deposit, and many of the specifics regarding lithium processing are proprietary. Compounding the potential variability across production sites, many companies use different techniques for lithium processing depending on the desired outputs. Influencing factors include the concentration and distribution of lithium minerals within the deposit, the overall grade of the deposit, the presence of contaminants (such as magnesium), and the location of the deposit (Garrett, [color=var(--article-body-links-color)]2004). Production system design may also vary by estimated returns on different grades of output, for example, low-grade hydroxides versus high-grade carbonate for LIBs, in addition to loss of product (e.g., tailings and slimes). The LCI model differentiates based on resource type and resource quality. Separate production models were developed for each of the two resource types, classified as other minerals (mostly pegmatites) or brines, and then tailored to specific deposit conditions based on ore grade and background systems (namely the fuel source and electricity grid).
锂生产过程可能因矿床而异，许多关于锂加工的具体细节都是专有的。另外，许多公司根据所需的产出采用不同的锂加工技术，这也增加了生产地点的潜在变化性。影响因素包括矿床中锂矿物的浓度和分布、矿床的整体品位、污染物（如镁）的存在以及矿床的位置（Garrett，2004）。生产系统设计也可能因不同产出品位的预期回报而有所不同，例如，低品位氢氧化物与高品位碳酸盐用于LIBs，另外还包括产品损失（如尾矿和泥浆）。LCI模型根据资源类型和资源质量进行区分。为两种资源类型（主要是长石岩和卤水）分别开发了生产模型，然后根据矿石品位和背景系统（即燃料来源和电力网）量身定制了特定的矿床条件。 [color=var(--article-headings-color)] For pegmatite resources, the first stage in production includes mining and raw ore recovery, which is affected by ore grade and depth of the deposit. The major processing steps for these hard-rock minerals involve screening, comminution, magnetic separation, froth flotation (FF), and drying (King, [color=var(--article-body-links-color)]2001). Screening is the initial step to separate inputs based on particle size, followed by crushing. There are many different methods to achieve crushing based on the inputs, desired outputs, and rate of production. Aside from the grinding, power supply for conveyors is also required to transport materials. Magnetic separation is used to remove any magnetized contaminants (such as iron). Although requirements range depending on the field strength needed, low intensity magnets can be used to generate up to a 15-kG field with only 16 kW of energy per pole needed (King, [color=var(--article-body-links-color)] 2001). The largest energy inputs directly associated with pegmatite processing are heating and comminution (Garrett, [color=var(--article-body-links-color)] 2004).
对于长石资源，生产的第一阶段包括采矿和原矿回收，这受矿石品位和矿床深度的影响。这些硬岩矿物的主要加工步骤包括筛分、粉碎、磁选、气泡浮选（FF）和干燥（King，2001）。筛分是根据颗粒大小进行初步分离的初始步骤，随后进行粉碎。有许多不同的方法可以根据输入、期望的输出和生产速率来实现粉碎。除了研磨外，还需要输送机的电力供应来运输材料。磁选用于去除任何磁化的污染物（如铁）。尽管所需的场强各不相同，但低强度磁铁可以产生高达15千高斯的场强，每极只需16千瓦的能量（King，2001）。与长石加工直接相关的最大能量输入是加热和粉碎（Garrett，2004）。 [color=var(--article-headings-color)] After recovery, raw ore is processed through one or more additional circuits: dry material separation and recovery, heavy liquid material separation including FF, and hydrometallurgical recovery (HMR). FF is a widely used technique in mineral processing to separate materials based on the ability of air bubbles to attract and remove certain particles while other particles remain behind (Kawatra & Eisele, [color=var(--article-body-links-color)]2002). The process is a highly variable step in pegmatite processing, primarily due to the unique physical and chemical properties of processing inputs depending on the location of mineral extraction (Menéndez, Vidal, Toraño, & Gent [color=var(--article-body-links-color)] 2004). FF involves dewatering, the production of a rougher float and a cleaner float, and thickening with a goal of maximizing a high degree of recovery and meeting market specifications. FF of lithium spodumene can be achieved through anionic or cationic flotation. Anionic flotation typically provides high-recovery rates, but lower purity concentrates, and vice versa for cationic flotation.
矿石经过回收后，将通过一个或多个额外的回路进行处理：干料分离和回收、重液体材料分离包括FF，以及水冶回收（HMR）。FF是矿物加工中广泛使用的技术，它基于空气泡吸引和去除特定颗粒的能力，而其他颗粒则留在原地（Kawatra & Eisele, 2002）。该过程在长石岩加工中是一个高度可变的步骤，主要是由于加工输入的独特物理和化学特性取决于矿产提取的位置（Menéndez, Vidal, Toraño, & Gent 2004）。FF包括脱水、生产粗浮选和精浮选，以及通过增稠来实现最大程度的回收和满足市场规格的目标。锂辉石的FF可以通过阴离子或阳离子浮选来实现。阴离子浮选通常提供高回收率，但纯度较低的浓缩物，而阳离子浮选则相反。 [color=var(--article-headings-color)] In terms of energy inputs, FF does not require a significant amount of direct energy, but that does not account for any energy inputs for producing chemicals used in FF. Additional processing also increases production costs, and energy inputs increase across the three processes. For FF and HMR, reagent inputs are also extensive. Reagent costs can represent 50% or more of average production costs, and additional FF and HMR processing may be required to concentrate and refine lower grade mineral deposits (Staiger & Rödel, [color=var(--article-body-links-color)]2017).
就能源投入而言，FF并不需要大量直接能源，但这并不包括用于生产FF中使用的化学品的能源投入。额外的加工也会增加生产成本，而且在三个过程中能源投入也会增加。对于FF和HMR，试剂的投入也是相当大的。试剂成本可能占平均生产成本的50%或更多，而且可能需要额外的FF和HMR加工来浓缩和提炼较低品位的矿床（Staiger & Rödel, 2017）。 [color=var(--article-headings-color)] For brines, extraction begins with drilling to pump lithium brines to the surface, which are then often collected in solar evaporation pools. Impurities in the final brine include boron, magnesium, and calcium. Unless processing facilities are located on-site or close to the evaporation ponds, the brine must be shipped via truck or rail to a processing plant. The major processes involved in the production of commercial-grade lithium products from brine sources are impurity removal, settling, filtering, pressing, heating, precipitation, and thickening/drying (King, [color=var(--article-body-links-color)]2001).
对于卤水，提取过程始于钻井将锂卤水抽到地表，然后通常在太阳蒸发池中收集。最终卤水中的杂质包括硼、镁和钙。除非加工设施位于现场或靠近蒸发池，否则卤水必须通过卡车或铁路运往加工厂。从卤水来源生产商业级锂产品的主要过程包括去除杂质、沉淀、过滤、压榨、加热、沉淀和浓缩/干燥（King, 2001）。 [color=var(--article-headings-color)] Impurity removal is done as an initial step to remove contaminants, including but not limited to boron, magnesium, and calcium. Boron is removed through solvent extraction. Magnesium and calcium are removed with lime and soda ash, respectively. The percentage of these contaminants in the brine directly affects the amount of solvents or chemicals and processing needed to remove a given impurity (Garrett, [color=var(--article-body-links-color)]2004). Accordingly, the value of a given brine source will range depending on the percentage of contaminants it contains. After the initial impurity removal, the remaining mixture progresses through a settling, filtration, and pressing process. Settling can be achieved via gravitational forces. Filter pressing requires pumps that vary in power use and efficiency depending on the inputs and rates of production. The goal of these processes is to increase the concentration of solid matter in the brine and remove unnecessary water and liquids.
杂质去除是作为初始步骤进行的，以去除包括但不限于硼、镁和钙在内的污染物。硼通过溶剂萃取去除。镁和钙分别通过石灰和苏打灰去除。卤水中这些污染物的百分比直接影响去除特定杂质所需的溶剂或化学品和加工量（Garrett，2004）。因此，给定卤水来源的价值将取决于其含有的污染物百分比。在初始杂质去除后，剩余混合物经过沉降、过滤和压榨过程。沉降可以通过重力作用实现。过滤压榨需要使用功率和效率因输入和生产速率而异的泵。这些过程的目标是增加卤水中固体物质的浓度，并去除不必要的水和液体。 [color=var(--article-headings-color)] The most energy intensive step to lithium brine processing (not including energy for chemical additives) is the thickening and drying processes. Settling and filtering require very low-energy inputs and can rely mostly on gravitational forces. After heating and precipitation of lithium carbonate, the resulting solution must be thickened. Sedimentation uses cycles and vacuum belts for the thickening process. The heating and drying is usually achieved through a rotary steam tube. These machines typically operate with a combustion chamber to achieve temperatures of approximately 980°C. Lithium chloride and the concentrate is then made into lithium hydroxide or treated with sodium carbonate to produce lithium carbonate. Additional thermal energy is often required for concentrating brines, which may rely on locally available primary energy sources such as geothermal resources (Yu, Zheng, Wu, Nie, & Bu, [color=var(--article-body-links-color)]2015).
锂卤水处理中能耗最高的步骤（不包括化学添加剂的能耗）是浓缩和干燥过程。沉降和过滤需要非常低能量输入，主要依靠重力。在加热和沉淀出碳酸锂后，产生的溶液必须进行浓缩。沉淀采用循环和真空带进行浓缩过程。加热和干燥通常通过旋转蒸汽管实现。这些机器通常配有燃烧室，以达到约980°C的温度。然后将氯化锂和浓缩物制成氢氧化锂，或者用碳酸钠处理以制得碳酸锂。通常还需要额外的热能来浓缩卤水，这可能依赖于当地可用的地热资源（于正武聂布，2015年）。 [color=var(--article-headings-color)] Though ore grades and geologic conditions are continuous variables, to make engineering model development and LCI model development manageable, all deposits are modeled as one of six hypothetical lithium production routes, three designations in descending order of preference for each of two categories of deposits; brines and other minerals. Brines are grouped as high-grade brine, low-grade brine, and low-grade brine with low solar evaporation potential. Other mineral deposits are grouped as high-grade pegmatite, low-grade pegmatite, and low-grade lithium minerals (i.e., those where the main lithium mineral is not identified, and/or is not a pegmatite or spodumene). Throughput, efficiency, and material and energy inputs are estimated based on company reporting, patents, and prior studies (An et al., [color=var(--article-body-links-color)]2012; Garrett, [color=var(--article-body-links-color)] 2004; Laferriere et al., [color=var(--article-body-links-color)] 2012; Stamp et al., [color=var(--article-body-links-color)] 2012). Reference LCI datasets for subprocesses and production inputs were taken from the Ecoinvent Database Version 3.3 (Ecoinvent Centre, [color=var(--article-body-links-color)] 2017). To represent variability in energy generation, inventories for grid electricity were selected based on the region of the deposit. A full list of reference LCI datasets, as well as graphical descriptions of the process models, is provided in Section [color=var(--article-body-links-color)] S1 of Supporting Information [color=var(--article-body-links-color)] S1.
尽管矿石品位和地质条件是连续变量，为了使工程模型开发和生命周期评价模型开发可管理，所有矿床都被建模为六种假设锂生产路线中的一种，每种矿床类型分为三种偏好顺序的指定类别：卤水和其他矿物。卤水被分为高品位卤水、低品位卤水和低品位卤水低太阳蒸发潜力。其他矿床被分为高品位长石、低品位长石和低品位锂矿物（即主要锂矿物未被识别和/或不是长石或锂辉石）。通过公司报告、专利和先前研究（An等，2012；Garrett，2004；Laferriere等，2012；Stamp等，2012）估计了产量、效率以及物质和能源投入。子过程和生产投入的参考生命周期评价数据集取自Ecoinvent数据库第3.3版（Ecoinvent Centre，2017）。为了代表能源生成的变异性，基于矿床所在地区选择了电网电力的清单。 支持信息S1的第S1部分提供了参考LCI数据集的完整列表，以及过程模型的图形描述。
生命周期影响评价[color=var(--article-headings-color)] The LCA model applies the US Environmental Protection Agency's Tool for the Reduction and Assessment of Chemical and other Environmental Impacts (TRACI) impact assessment model (Bare, [color=var(--article-body-links-color)]2011). The following impact categories were considered: global warming potential (GWP), acidification potential, ozone depletion potential, eutrophication potential, photochemical smog formation potential, human health —particulate, human health—cancer, and ecotoxicity. Additional information on the selected impact categories and the indicators used to represent them is provided in Section [color=var(--article-body-links-color)] S2 of Supporting Information [color=var(--article-body-links-color)] S1.
该LCA模型应用了美国环境保护局的化学和其他环境影响减少和评估工具（TRACI）影响评估模型（Bare, 2011）。考虑了以下影响类别：全球变暖潜势（GWP）、酸化潜势、臭氧消耗潜势、富营养化潜势、光化学烟雾形成潜势、人类健康—颗粒物、人类健康—癌症和生态毒性。有关所选影响类别和用于代表它们的指标的附加信息，请参阅支持信息S1的S2部分。
3.1 生产途径的LCA结果[color=var(--article-headings-color)] While there are significant differences in energy inputs and throughput efficiencies across production pathways, impact assessment results do not show dramatic differences in most environmental impact categories (Figure [color=var(--article-body-links-color)]2). Figure [color=var(--article-body-links-color)] 2 uses the weighted average region for each production pathway to estimate impacts from electricity consumed. In general, high- and low-grade brines show the most favorable results (i.e., lowest results) for toxicity-related impact categories and human health impacts from air emissions. High- and low-grade pegmatites show more favorable results for GWP, smog formation, and acidification. These results are primarily explained by differences in the chemical flows between brine and hard-rock mining and extraction processes. We find moderate variation between the most favorable and least favorable potential brine production pathways, with additional fuel use for drying in the “Unfavorable Conditions” brine scenario driving significantly higher toxicity-related air, water, and human health impacts.
虽然在生产途径中能源投入和吞吐效率存在显著差异，但影响评估结果在大多数环境影响类别中并未显示出显著差异（图2）。图2使用每种生产途径的加权平均区域来估计所消耗电力的影响。总体而言，高、低品位卤水显示出毒性相关影响类别和空气排放对人类健康的影响方面最有利的结果（即最低结果）。高、低品位长石岩显示出更有利的结果，包括全球变暖潜势、烟雾形成和酸化。这些结果主要是由于卤水和硬岩矿山开采和提取过程之间化学流动的差异所解释的。我们发现在最有利和最不利的潜在卤水生产途径之间存在适度的变化，其中在“不利条件”卤水情景中用于干燥的额外燃料使用显著提高了毒性相关的空气、水和人类健康影响。  Figure 2 图2[color=var(--article-body-links-color)]Open in figure viewer
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[size=0.75]Impact assessment of lithium production pathways (AP, acidification potential in g SO3-eq; ETP, ecotoxicity potential in CTUe; EP, eutrophication potential in g N-eq; GWP, global warming potential in kg CO2-eq; HHP, human health particulate in g PM2.5-eq; HHC, human health cancer in CTUh × 108; HHNC, human health noncancer in CTUh × 107; ODP, ozone depletion potential in mg × 107 CFC-11-eq; SFP, smog formation potential in kg × 10 O3-eq). Underlying data used to create this figure can be found in Supporting Information [color=var(--article-body-links-color)]S2
锂生产途径的影响评估（AP，酸化潜势以g SO 3 -eq计; ETP，生态毒性潜势以CTUe计; EP，富营养化潜势以g Neq计; GWP，全球变暖潜势以kg CO 2 eq计; HHP，人类健康颗粒物以g PM 2.5 eq计; HHC，人类健康癌症以CTUh×10 8 计; HHNC，人类健康非癌症以CTUh×10 7 计; ODP，臭氧消耗潜势以mg×10 7 CFC-11eq计; SFP，雾霾形成潜势以kg×10 O 3 eq计）。创建此图所使用的基础数据可在支持信息S2中找到。
3.1.1 Impacts over time
3.1.1 随时间的影响[color=var(--article-headings-color)] Combining the impact analysis with the resource projection, we observe the potential changes in impacts over time under the optimistic scenario (Figure [color=var(--article-body-links-color)]3). Increasing impacts on fresh water, local air quality, and human health are likely to be concentrated around smaller deposits, which are likely to be developed after 2050. Notably, global warming impact intensity from LCE production does not change significantly over time, however, given significant growth in LCE production, total CO2e emissions from the lithium production sector will increase significantly. There can be significant interannual variations in production share across lithium resources due to overall market expansion, production capacity increases, and climate conditions for brine production. These effects are observable in Figure [color=var(--article-body-links-color)] 3 as rapid shifts between years when new deposits are brought online. As the market for lithium continues to grow after 2050, these shifts are less noticeable as fewer new deposits with significant production potential come online. A shift in future supply toward lower grade resources did not translate to significantly higher environmental impacts for lithium carbonate on average.
将影响分析与资源预测相结合，我们观察到乐观情景下时间内影响的潜在变化（图3）。淡水、当地空气质量和人类健康受到的影响可能会集中在较小的矿床周围，这些矿床可能在2050年后开发。值得注意的是，LCE生产对全球变暖的影响强度随时间并未发生显著变化，然而，鉴于LCE生产的显著增长，锂生产部门的总CO2排放将显著增加。由于整体市场扩张、生产能力增加和卤水生产的气候条件，锂资源的生产份额可能会出现显著的年际变化。这些影响在图3中可观察到，表现为新矿床上线时年份之间的快速转变。随着2050年后锂市场的持续增长，这些转变变得不那么明显，因为上线的具有显著生产潜力的新矿床较少。未来供应向较低品位资源的转变并未导致碳酸锂的环境影响显著增加。  Figure 3 图3[color=var(--article-body-links-color)]Open in figure viewer
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[size=0.75]Impact assessment of production weighted lithium production over time (AP, acidification potential in g SO3-eq; ETP, ecotoxicity potential in CTUe; EP, eutrophication potential in g N-eq; GWP, global warming potential in kg CO2-eq; HHP, human health particulate in g PM2.5-eq; HHC, human health cancer in CTUh × 108; HHNC, human health noncancer in CTUh × 107; ODP, ozone depletion potential in mg × 107 CFC-11-eq; SFP, smog formation potential in kg × 10 O3-eq). Underlying data used to create this figure can be found in Supporting Information [color=var(--article-body-links-color)]S2
随着时间推移，生产加权锂生产的影响评估（AP，酸化潜势，以克SO 3 -eq计量；ETP，生态毒性潜势，以CTUe计量；EP，富营养化潜势，以克Neq计量；GWP，全球变暖潜势，以千克CO 2 eq计量；HHP，人类健康颗粒物，以克PM 2.5 eq计量；HHC，人类健康癌症，以CTUh×10 8 计量；HHNC，人类健康非癌症，以CTUh×10 7 计量；ODP，臭氧消耗潜势，以毫克×10 7 CFC-11eq计量；SFP，烟雾生成潜势，以千克×10 3 Oeq计量）。创建此图所使用的基础数据可在支持信息S2中找到。
[color=var(--article-headings-color)] Under the optimistic scenario, a larger share of production is supplied from lower-grade mineral deposits after 2080, but high- and low-grade brines continue to be the largest source of supply. This is due to both the increased demand for lithium, as well as the limits on potential production from lower cost brines. Comparing the average impacts per kg LCE over 2, 10-year periods, beginning in 2020 and 2080, significant increases in production from low-grade pegmatite and brine resources leads to only small increases in environmental impacts. For example, GWP increases by 3% from 3.2 to 3.3 kg CO2e/kg LCE. This translates to an increase of 0.14 to 0.16 kg CO2e/kWh of cathode material, assuming a nickel cobalt aluminum or manganese cathode precursor and a cathode energy density of 0.25 to 0.27 kWh/kg (Ciez & Whitacre, [color=var(--article-body-links-color)]2019). Changes to water, toxics and particulate matter were larger than GWP, increasing by 11, 12, and 15%, respectively. While the impact intensity (i.e., impact per kg of LCE) does not change significantly over time, given significant growth in LCE production, total impacts from the lithium production sector will increase significantly. For example, sector-wide CO2e emissions increased by at least two orders of magnitude between 2020 and 2080 (Figure [color=var(--article-body-links-color)] S3-2 of Supporting Information [color=var(--article-body-links-color)] S1).
在乐观的情景下，到2080年后，更多的产量将来自低品位矿床，但高低品位卤水仍将是最大的供应来源。这是由于对锂的需求增加，以及来自低成本卤水的潜在生产限制。比较2020年和2080年开始的两个10年期间每千克LCE的平均影响，从低品位长石和卤水资源的生产显著增加只导致环境影响略微增加。例如，GWP从3.2增加到3.3千克CO2e/千克LCE，增加了3%。这相当于假设镍钴铝或锰阴极前体和阴极能量密度为0.25至0.27千瓦时/千克时，从0.14增加到0.16千克CO2e/千瓦时的阴极材料。水、有毒物质和颗粒物的变化比GWP更大，分别增加了11%、12%和15%。虽然影响强度（即每千克LCE的影响）随时间变化不大，但鉴于LCE产量的显著增长，锂生产部门的总体影响将显著增加。 例如，2020年至2080年间，整个行业的CO 2 e排放量至少增加了两个数量级（支持信息S1的图S3-2）。 [color=var(--article-headings-color)] Under the conservative demand scenario, there is no significant future development of low grade, hard-rock sources of lithium. This result in a 48–64% reduction in sector-wide environmental impacts from global LCE production in 2100 compared with the optimistic demand scenario (Figure [color=var(--article-body-links-color)]S3-4 of Supporting Information [color=var(--article-body-links-color)] S1). In addition, significant increases in the average impacts on ecotoxicity, eutrophication, and human exposure to particulates per kg of LCE after 2080 did not occur (Figure [color=var(--article-body-links-color)] S3-5 of Supporting Information [color=var(--article-body-links-color)] S1). An expanded description of results, including global sector-wide results, and data tables are provided in Section [color=var(--article-body-links-color)] S3 of Supporting Information [color=var(--article-body-links-color)] S1.
在保守的需求情景下，未来低品位、硬岩石锂资源的开发并不显著。与乐观的需求情景相比，这导致了2100年全球LCE生产的行业范围环境影响减少了48-64%（详见支持信息S1的图S3-4）。此外，2080年后，每千克LCE的生态毒性、富营养化和人类暴露于颗粒物的平均影响并未显著增加（详见支持信息S1的图S3-5）。关于全球行业范围结果和数据表的扩展描述，请参阅支持信息S1的第S3部分。 [color=var(--article-headings-color)]Uncertainty in the results of an LCA can result from a number of sources: variability in assumed values, lack of knowledge, measurement errors, and choices related to model design and specification. We considered the impacts of parametric uncertainty on model findings, specifically discount rate, production costs, reagent use, production energy inputs and sources, and mineral grade/type. Changes to discount rate and production costs did not cause significant changes in the overall production forecast, but did affect year-to-year variation in estimated impacts. This is also due to assumptions around the rate of potential production capacity expansion at existing and new lithium deposits. Estimated production impacts are highly sensitivity to the extent of HMR processing, while the impacts of HMR processing are primarily due to consumption of reagents for collection and dispersion.
LCA结果的不确定性可能来自多个来源：假定值的变异性、缺乏知识、测量误差以及与模型设计和规范相关的选择。我们考虑了参数不确定性对模型结果的影响，特别是折现率、生产成本、试剂使用、生产能源投入和来源，以及矿石品位/类型。折现率和生产成本的变化并未导致整体生产预测发生显著变化，但确实影响了估计影响的年度变化。这也是由于对现有和新的锂矿床潜在生产能力扩展速率的假设。估计的生产影响对HMR处理程度非常敏感，而HMR处理的影响主要是由于用于收集和分散的试剂的消耗。 [color=var(--article-headings-color)] For brine production, two primary sources of uncertainty are variability in the effective evaporation rate of solar ponds and the use of external energy sources to dry aqueous brines. Small increases in annual precipitation can cause months-long disruptions in the production of solar evaporated brines, as was experienced in the Atacama region in 2015 (Abad, Rolando, & Izquierdo, [color=var(--article-body-links-color)]2017). The use of natural gas for drying in the worst-case scenario for brine production was the key factor driving increased impacts.
对于盐水生产，两个主要的不确定性来源是太阳能池有效蒸发速率的变化和使用外部能源干燥水溶性盐水。年降水量的小幅增加可能导致太阳能蒸发盐水生产数月的中断，正如2015年在阿塔卡马地区所经历的那样（Abad, Rolando, & Izquierdo, 2017）。在最坏的情况下，使用天然气进行干燥是增加影响的关键因素。 [color=var(--article-headings-color)] A limitation of this study is the use of temporally static LCIs for regional electricity generation and processing technologies that may not reflect changing energy sources for electricity generation (e.g., decreased consumption of coal and increased use of renewables), or advances in machinery (e.g., improved heat rates for drying machinery). While impacts of regional electricity and natural gas sources were included, this did not result in significant differences across regions under current conditions. Given the large contribution of a single-brine deposit to global supply, development of local renewable resources, including geothermal and solar energy, could likely reduce the emissions associated with overall lithium production (Lahsen, Muñoz, & Parada, [color=var(--article-body-links-color)]2010; Parrado, Girard, Simon, & Fuentealba, [color=var(--article-body-links-color)] 2016).
该研究的局限性在于使用时间静态的LCI来进行区域电力生产和加工技术的分析，这可能无法反映电力生产能源的变化（例如，煤炭消耗减少和可再生能源利用增加），或者机械技术的进步（例如，改进的干燥机械热效率）。虽然考虑了区域电力和天然气来源的影响，但在当前条件下，这并未导致不同地区之间出现显著差异。鉴于单一卤水矿床对全球供应的巨大贡献，发展当地的可再生资源，包括地热和太阳能，可能会减少与锂总产量相关的排放（Lahsen, Muñoz, & Parada, 2010; Parrado, Girard, Simon, & Fuentealba, 2016）。 [color=var(--article-headings-color)] The results of this study generally agree with existing estimates of life-cycle impacts from LCE production. Figure [color=var(--article-body-links-color)]4 shows the average results for impacts across rock and brine resources from 2020 to 2100, with error bars indicating the minimum and maximum values observed across production pathways, compared with the inventories for LCE production from Ecoinvent for spodumene and brine, respectively.
该研究的结果通常与现有的LCE生产生命周期影响估计相吻合。图4显示了2020年至2100年间岩石和卤水资源的影响平均结果，误差线显示了在生产途径中观察到的最小和最大值，与Ecoinvent对锂辉石和卤水LCE生产的清单进行了比较。  Figure 4 图4[color=var(--article-body-links-color)]Open in figure viewer
在图像查看器中打开[color=var(--article-body-links-color)]PowerPoint
[size=0.75]Comparison of findings with existing impact estimates pathways (AP, acidification potential in g SO3-eq; ETP, ecotoxicity potential in CTUe; EP, eutrophication potential in g N-eq; GWP, global warming potential in kg CO2-eq; HHP, human health particulate in g PM2.5-eq; HHC, human health cancer in CTUh × 108; HHNC, human health noncancer in CTUh × 107; ODP, ozone depletion potential in mg × 107 CFC-11-eq; SFP, smog formation potential in kg × 10 O3-eq). Underlying data used to create this figure can be found in Supporting Information [color=var(--article-body-links-color)]S2
与现有影响估计途径的发现进行比较（AP，硫化物酸化潜力，以克SO 3 -eq计算；ETP，生态毒性潜力，以CTUe计算；EP，富营养化潜力，以克Neq计算；GWP，全球变暖潜力，以千克CO 2 eq计算；HHP，人类健康颗粒物，以克PM 2.5 eq计算；HHC，人类健康癌症，以CTUh × 10 8 计算；HHNC，人类健康非癌症，以CTUh × 10 7 计算；ODP，臭氧消耗潜力，以毫克×10 7 CFC-11eq计算；SFP，烟雾生成潜力，以千克×10 O 3 eq计算）。创建此图所使用的基础数据可在支持信息S2中找到。
[color=var(--article-headings-color)] Other life-cycle based studies have also reported results that can be compared to findings from this study. Gaines and Nelson ([color=var(--article-body-links-color)]2010) estimate that 163 MJ are required per kg to process ore into lithium hydroxide at a marketable condition. For the processing of brines into lithium carbonate, they estimated 44.7 MJ per kg were required, with 78% of that energy coming from fuel oils, 4% coming from propane, and the remainder coming from coal. The present study found energy inputs for producing LCE from pegmatites to range from 72 to 230 MJ/kg, while energy inputs from brines ranged 31 to 89 MJ/kg. In comparison to Gaines et al.’s findings, the present study found that energy inputs were lower for high-grade resources, but significantly higher for low-grade resources in unfavorable conditions. The scope of the current environmental assessment is limited in that it did not include site impacts including land transformation for solar evaporation ponds, or site impacts to air and water from the storage/disposal of mining wastes. While energy sources were estimated for deposit regions, these values were treated as static. Changes to the primary energy sources (i.e., a shift from coal to gas or renewables), or improvements in the efficiency of generation technologies could reduce the impacts of producing a kg of LCE. In addition, the reference data used may not accurately reflect the impacts associated with a particular source or supply for reagents or energy sources.
其他基于生命周期的研究也报告了可以与本研究结果进行比较的结果。Gaines和Nelson（2010）估计每公斤将矿石加工成可销售状态的羟化锂需要163兆焦耳。对于将卤水加工成碳酸锂，他们估计每公斤需要44.7兆焦耳，其中78%的能量来自燃料油，4%来自丙烷，其余来自煤。本研究发现，从长石岩产出LCE的能量投入范围为72至230兆焦耳/公斤，而卤水的能量投入范围为31至89兆焦耳/公斤。与Gaines等人的研究结果相比，本研究发现高品位资源的能量投入较低，但在不利条件下低品位资源的能量投入显著较高。当前环境评估的范围有限，因为它没有包括太阳蒸发池的土地转型等现场影响，或者矿业废物的存储/处置对空气和水的现场影响。虽然对矿床地区的能源来源进行了估计，但这些值被视为静态值。对主要能源来源（即从煤炭转向天然气或可再生能源，或者发电技术的改进可能会减少生产一公斤锂化学电池所带来的影响。此外，所使用的参考数据可能无法准确反映与特定来源或试剂或能源供应相关的影响。
4.1回收电池、回收锂和非传统资源[color=var(--article-headings-color)] Though excluded from the resource model in this analysis, recycling of batteries could be an important source of future lithium supply (Gruber et al., [color=var(--article-body-links-color)]2011; Pehlken, Albach, & Vogt, [color=var(--article-body-links-color)] 2015). Some previous studies have assumed widespread and effective recycling of LIBs as a major source of future lithium. Mohr, Mudd, and Giurco ([color=var(--article-body-links-color)] 2012) estimated recycled lithium could represent 50% or more of lithium demand by 2050. While there has been a proliferation of methods for recovering cathode materials, many developments remain at the laboratory scale, which is a challenge for prospective analysis of environmental impacts (Zeng, Li, & Singh, [color=var(--article-body-links-color)] 2014; Zhang et al., [color=var(--article-body-links-color)] 2018). Conventional material recycling processes can generally be divided into two categories: hydrometallurgical and pyrometallurgical. With the exception of some experimental in situ recycling processes, conventional pyrometallurgical recovery of high-value metal alloys, like nickel and copper, from spent LIBs does not produce lithium as a coproduct.
尽管在这项分析中被排除在资源模型之外，但电池的回收可能成为未来锂供应的重要来源（Gruber等，2011年；Pehlken，Albach和Vogt，2015年）。一些先前的研究假设广泛和有效的LIBs回收将成为未来锂的主要来源。Mohr，Mudd和Giurco（2012年）估计，到2050年，回收的锂可能占锂需求的50%或更多。尽管已经出现了许多用于回收正极材料的方法，但许多发展仍停留在实验室阶段，这对于环境影响的前瞻性分析构成了挑战（Zeng，Li和Singh，2014年；Zhang等，2018年）。传统的材料回收过程通常可以分为两类：湿法冶金和干法冶金。除了一些实验性的原位回收过程外，从废旧LIBs中传统的干法冶金回收高价值金属合金，如镍和铜，并不会产生锂作为副产品。 [color=var(--article-headings-color)] The focus of most existing recycling efforts for LIBs has been on recovering cobalt, due to both the quantity of cobalt in the cathode of batteries for consumer electronics (i.e., LCO), and the high value of recovered cobalt (Zhang et al., [color=var(--article-body-links-color)]2018). Attention has shift to recovering other high-value materials, like nickel, copper, and aluminum, as battery systems have increased in size and cobalt content has fallen (Gaines, [color=var(--article-body-links-color)] 2018). For large format LIBs, widely expected to drive demand for lithium in the future, coprecipitation of lithium–nickel cathode materials combined with relithiation, sometimes called direct cathode recovery, is a promising pathway. Ciez and Whitacre ([color=var(--article-body-links-color)] 2019) recently examined the environmental impacts and costs of recycling processes for LIBs including resynthesis of cathodes through direct cathode recovery at high-cathode recovery rates (Ciez & Whitacre, [color=var(--article-body-links-color)] 2019). The authors found limited to insignificant benefits for battery GHG emissions from cathode recycling through hydrometallurgical or pyrometallurgical processes. The limited studies available suggest that recovery of lithium from spent cells provides no clear environmental or economic benefit. Recovery of aluminum, the largest contributor to energy for cell materials and material-related GHG emissions, and copper collector foils could reduce energy for cell material production by 70 to 80 MJ/kg of battery cells, or 34–69% (Dunn, Gaines, Kelly, James, & Gallagher, [color=var(--article-body-links-color)] 2015; Gaines, [color=var(--article-body-links-color)] 2018). The cost of leaching chemicals for lithium carbonate from recycled batteries could be more than the $8 per kg or $8000 per metric ton LCE (Gratz, Sa, Apelian, & Wang, [color=var(--article-body-links-color)] 2014). This suggests the price of recycled lithium carbonate would be significantly higher than the average cost of production of lithium from primary sources.
大多数现有的LIBs回收工作的重点一直放在回收钴上，这是因为消费电子产品电池（即LCO）中钴的数量以及回收钴的高价值（Zhang等，2018）。随着电池系统的尺寸增加和钴含量的下降，人们开始关注回收其他高价值材料，如镍、铜和铝（Gaines，2018）。对于预计将来推动锂需求的大型LIBs，共沉淀锂-镍阴极材料结合重锂化，有时被称为直接阴极回收，是一条有前途的途径。Ciez和Whitacre（2019）最近研究了包括高阴极回收率的直接阴极回收在内的LIBs回收过程的环境影响和成本（Ciez＆Whitacre，2019）。作者发现，通过湿法冶金或干法冶金过程回收阴极对电池温室气体排放的益处有限至微不足道。有限的研究表明，从废旧电池中回收锂并没有明显的环境或经济效益。 铝的回收，作为电池材料和相关温室气体排放的最大贡献者，以及铜集电箔的回收，可以将电池材料生产的能耗降低70至80兆焦耳/千克电池，或34-69%（Dunn, Gaines, Kelly, James, & Gallagher, 2015; Gaines, 2018）。从回收电池中提取碳酸锂的浸出化学品成本可能超过每千克8美元或每公吨8000美元的锂碳酸盐当量（Gratz, Sa, Apelian, & Wang, 2014）。这表明回收的碳酸锂的价格将显著高于从原始来源生产锂的平均成本。 [color=var(--article-headings-color)] In addition, successful recycling programs for e-wastes are an issue, as current collection rates for LIBs are approximately 3% (Swain, [color=var(--article-body-links-color)]2017). While collection rates might be significantly improved for large-format LIBs over those in the general e-waste stream, a confounding factor for battery recycling economics is the potential for second-use applications of large-format LIBs in stationary applications. The primary determination of LIB service life in vehicles is power fade, and LIBs employed in high-power vehicle applications are likely to still have considerable capacity when retired. A growing body of research has pointed to the technical and economic feasibility of LIB reuse or second life (Ahmadi, Young, Fowler, Fraser, & Achachlouei, [color=var(--article-body-links-color)] 2017; Martinez-Laserna et al., [color=var(--article-body-links-color)] 2018; Richa, Babbitt, Nenadic, & Gaustad, [color=var(--article-body-links-color)] 2017). To the extent batteries could be employed in secondary applications, batteries may remain in service longer. The value of recovered materials from recycled batteries may also be too low to motivate sufficient development of recycling infrastructure or to compete economically with second-life applications (Ambrose, Gershenson, Gershenson, & Kammen, [color=var(--article-body-links-color)] 2014; Ciez & Whitacre, [color=var(--article-body-links-color)] 2019).
此外，电子废物的成功回收计划也是一个问题，因为目前LIB的收集率约为3%（Swain，2017年）。虽然大型LIB的收集率可能比一般电子废物流中的收集率有显著提高，但对电池回收经济的一个混淆因素是大型LIB在固定应用中的二次使用潜力。在车辆中，LIB的主要确定因素是功率衰减，而在高功率车辆应用中使用的LIB在退役时可能仍具有相当的容量。越来越多的研究指出了LIB再利用或二次寿命的技术和经济可行性（Ahmadi，Young，Fowler，Fraser和Achachlouei，2017年；Martinez-Laserna等，2018年；Richa，Babbitt，Nenadic和Gaustad，2017年）。在一定程度上，电池可以用于二次应用，电池可能会使用更长时间。 回收电池材料的价值可能也太低，无法激励足够的回收基础设施发展，也无法在经济上与二次利用应用竞争（Ambrose, Gershenson, Gershenson, & Kammen, 2014; Ciez & Whitacre, 2019）。 [color=var(--article-headings-color)]Part one of this study assessed the potential for secondary lithium from recycled LIBs using a stock and flow model. Assuming a high rate of LIB collection at end-of-life (85%), and assuming approximately half of all vehicle LIBs find secondary uses, the model showed the total stock of LCE in waste batteries awaiting recycling could approach 25% of global primary reserves by 2100. The potential stock of LIB materials in retired LIBs could also grow as improvements to recycling technologies increase recovery rates. As LIB recycling processes and their technical, economic and environmental performance become clearer, future research could explore the effect of secondary lithium flows on the environmental intensity of average global lithium production.
本研究的第一部分评估了使用库存和流动模型从回收LIBs中获取二次锂的潜力。假设LIB在寿命结束时的高回收率为85%，并假设大约一半的车辆LIB可以找到二次用途，该模型显示到2100年，等待回收的废旧电池中的LCE总库存可能接近全球原始储量的25%。随着回收技术的改进提高回收率，废弃LIB中LIB材料的潜在库存也可能增长。随着LIB回收过程及其技术、经济和环境性能变得更加清晰，未来的研究可以探讨二次锂流对全球平均锂生产的环境强度的影响。 5 CONCLUSIONS 5个结论[color=var(--article-headings-color)]Despite differences in impacts by production pathway and a changing mix of resources being dispatched over time, the average impact intensity of a kg of LCE changes very little even out to 2100, though some impact categories (including eutrophication, ecotoxicity, and human health particulate) do show nontrivial increases around 2080 corresponding with new capacity from low-grade mineral ores. Examining results on a per-kg basis can be somewhat misleading, however, because the total quantity of lithium produced is increasing rapidly, meaning that total impacts from the sector will be much larger than today. Moreover, the impacts experienced by the communities that host lithium mining and processing sites may change dramatically when capacity is expanded or a new mine is opened. In addition, the significant variability in environmental protections and enforcement in different regions over the world means that the estimates provided here probably underestimate the variability across production sites. Thus, the industry (or the industries reliant on lithium) should consider focusing on reducing impacts per unit of lithium production to prevent significant increases in the total burden of pollution from lithium production and to protect the communities where lithium is produced.
尽管生产途径和随时间推移被调度的资源组合的影响有所不同，但到2100年，每公斤锂碳酸盐的平均影响强度变化很小，尽管一些影响类别（包括富营养化、生态毒性和人类健康颗粒物）在2080年左右显示出相应于低品位矿石新产能的显著增加。然而，基于每公斤的结果可能有些误导，因为锂的总产量正在迅速增加，这意味着该行业的总影响将远远大于今天。此外，承载锂矿山和加工厂的社区所经历的影响可能在产能扩大或新矿山开放时发生巨大变化。此外，全球不同地区环境保护和执法的显著变化意味着这里提供的估计可能低估了生产地点之间的变异性。 因此，该行业（或依赖锂的行业）应考虑专注于减少每单位锂生产的影响，以防止锂生产的总污染负担显著增加，并保护锂生产所在的社区。 [color=var(--article-headings-color)]Given these findings, future work might consider assessments that evaluate local conditions of production on a site-by-site basis to capture the variability in environmental impacts, not to mention the socioeconomic impacts, caused by expanding capacity at current sites and exploitation of new deposits. Given the significance of other constituent cathode and electrode materials, future resource analysis could also focus on cobalt (and to a lesser extent nickel). The underlying resource model used to develop this temporally and spatially resolved LCA could facilitate site-specific assessment of impacts likely to be experienced by communities under different demand forecasts, which could be important for understanding which communities may be disproportionately impacted.
鉴于这些发现，未来的工作可能会考虑评估生产现场的当地条件，以捕捉由于扩大当前现场的产能和开采新矿床所引起的环境影响的变化，更不用说由此带来的社会经济影响。鉴于其他主要的阴极和电极材料的重要性，未来的资源分析也可以着重考虑钴（以及在较小程度上的镍）。用于开发这种时间和空间分辨率的LCA的基础资源模型可以促进对不同需求预测下社区可能经历的影响进行现场特定评估，这对于了解哪些社区可能受到不成比例的影响可能很重要。
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发表于 2023-12-21 14:20:08
