A Guide to Selecting Lithium Ore Processing Equipment

The lithium rush has many treating lithium ore like any other base metal. This common assumption is a fast path to financial disaster and operational failure.

The type of lithium ore, whether spodumene or lepidolite, dictates the entire processing flowsheet and equipment selection. This is due to fundamental differences in mineralogy, liberation characteristics, and associated impurities, which make a one-size-fits-all approach impossible for a successful Lithium Ore Processing Plant.

For over fifty years, I have seen that those who survive commodity cycles are the ones who respect the unique personality of their ore. Lithium is sensitive and demands a custom-tailored approach. This guide provides the ground truth on selecting the right lithium ore processing equipment.

Why Must You First Study the Ore’s Mineralogy?

Before you even think about a single machine, you must conduct a detailed process mineralogy study. This is the single most important step. It’s like a doctor performing a full diagnosis before prescribing medicine. A simple chemical assay tells you how much lithium is in your rock. A mineralogy study tells you how it exists, which is far more important.

This study answers critical questions that dictate your entire flowsheet:

• What is the lithium-bearing mineral? Is it spodumene, lepidolite, zinnwaldite, or something else? They behave completely differently.
• What is the grain size? Are the lithium crystals large and well-defined, or are they finely disseminated throughout the rock? This determines your required grinding size.
• What are the gangue (waste) minerals? Is it mainly quartz and feldspar? Are there troublesome micas or iron-rich minerals like tourmaline?
• How is it all locked together? This is called the texture. Understanding this tells you how much energy you need to break the rock to free the lithium minerals—a concept called liberation.
  Without this data, you are flying blind. With it, you can begin to design a smart, effective process.

What is the Standard Process for Spodumene Ore?

Spodumene is the most common hard-rock source of lithium. However, it presents a key challenge: its specific gravity (~3.2 g/cm³) is very close to that of quartz and feldspar (~2.6 g/cm³), its main companion minerals. This makes simple gravity separation ineffective. A typical high-performance spodumene processing flowsheet involves several key stages.

The goal is to reject as much waste as possible, as early as possible.

1. Crushing: A multi-stage circuit, usually with a Jaw Crusher for primary crushing, followed by one or two stages of Cone Crushers. The goal is to get the ore down to a manageable size, like below 15mm.
2. Dense Media Separation (DMS): This is often the secret weapon. The crushed ore is fed into a “heavy liquid” made of ferrosilicon and water. The lighter quartz and feldspar float and are rejected as waste. The heavier spodumene sinks and is collected. This can remove 30-50% of the plant feed before the expensive grinding stage.
3. Grinding: The spodumene concentrate from the DMS is then ground, typically in a Ball Mill, to liberate the fine spodumene particles for flotation. The key here is to avoid over-grinding, as very fine spodumene “slimes” are difficult to recover.
4. Flotation: This is the final concentration step. A specific set of chemical reagents is used to make the spodumene particles float in a Flotation Machine, separating them from any remaining waste minerals.
5. Iron Removal: A critical step for product quality. A Wet High-Intensity Magnetic Separator is often used before or after flotation to remove iron-bearing impurities.

How is Lepidolite Processing Different?

Lepidolite is a lithium-bearing mica. Its physical properties are completely different from spodumene, so the lepidolite processing flowsheet is also different.

The primary challenge with lepidolite is its flaky, plate-like shape. This makes it prone to creating slimes during grinding.

• No DMS: Dense Media Separation is generally not used for lepidolite. The entire process relies on flotation.
• Grinding Control is Crucial: The goal is to gently detach the lepidolite flakes without breaking them into ultra-fines. A Rod Mill can sometimes be preferred over a ball mill in the primary grinding stage as it produces fewer fines.
• Desliming is Key: Before flotation, a desliming stage using hydrocyclones is often necessary to remove the naturally occurring slimes and any ultra-fines created during grinding. These slimes consume a lot of expensive reagents and reduce flotation efficiency.
• Flotation-Centric Flowsheet: The process is built entirely around flotation. The choice of reagents and the pH conditions are tailored specifically to float the flaky lepidolite mineral away from the quartz and feldspar.

How to Select Your Crushing and Grinding Equipment?

The goal of the crushing and grinding circuit is to reduce the ore size just enough to liberate the valuable lithium minerals from the waste rock. The motto is “liberate, don’t obliterate.” Over-grinding creates slimes, which leads to poor recovery and high reagent costs.
Your equipment choice depends on the ore’s hardness and the target liberation size determined by your mineralogy study.

Equipment Type	Stage	Purpose	Why We Use It
Jaw Crusher	Primary Crushing	Breaks very large Run-of-Mine ore into a manageable size (-150mm).	Handles the largest, toughest rocks directly from the mine. A must-have first step.
Cone Crusher	Secondary/Tertiary Crushing	Reduces the ore size further (-15mm) in preparation for grinding or DMS.	Efficiently handles hard, abrasive ores. Settings can be adjusted for precise size control.
Ball Mill	Grinding	Grinds the crushed ore with water to a fine powder (e.g., -150 microns) for flotation.	A robust and reliable machine for fine grinding. Used in closed circuit with cyclones to prevent over-grinding.

Practical Tip for Grinding

For friable (brittle) ores like spodumene, consider a two-stage grinding circuit. A rod mill followed by a ball mill can minimize the generation of fines. High-Pressure Grinding Rolls (HPGRs) are also an excellent, though higher-CAPEX, option for this reason.

How to Choose Flotation Machines?

Flotation is the heart of most lithium ore processing equipment setups. The choice here isn’t just about the machine itself, but also about getting the total volume right.
Your beneficiation test will tell you the required residence time—how long the ore slurry needs to be in the flotation cells for the separation to occur. You calculate the required total volume like this:
Total Volume (m³) = [Plant Throughput (m³/hour)] x [Required Residence Time (hours)]
This total volume is then divided among a series of flotation cells. This series is split into “Rougher,” “Cleaner,” and “Scavenger” banks, each performing a different role to maximize both recovery and final concentrate grade. The physical machine type (e.g., self-aspirating or forced-air) is then selected based on the specific aeration and agitation needs of your ore and reagent scheme.

When Do You Need Magnetic or Gravity Separation?

These are specialized tools used to solve specific problems.

• Magnetic Separation: This is almost always required in a lithium plant. The goal is to remove iron impurities. Your final concentrate must have a very low iron content (typically <1% Fe₂O₃) to be accepted by chemical converters. A Wet High-Intensity Magnetic Separator (WHIMS) is the standard machine for this job.
• Gravity Separation: Because of the small density difference between lithium minerals and gangue, gravity separation (using spirals or jigs) is not effective for primary recovery. However, a Shaking Table may be used in the very final stage to polish a small stream of high-grade concentrate, but it is not a core part of the main flowsheet.

How Do Beneficiation Tests Finalize Equipment Selection?

If mineralogy is the diagnosis, then the beneficiation test is the detailed treatment plan. A full-scale lab test on a representative ore sample (a few hundred kilograms) provides the hard data needed to finalize your equipment list.
The test report will give you:

1. The optimal grind size. This tells you exactly how big your ball mill needs to be.
2. The complete flotation reagent scheme and dosages. This helps you design your reagent mixing and dosing system.
3. The required flotation residence time. This determines the number and size of your flotation cells.
4. A prediction of your final concentrate grade and recovery. This is the data you will use in your financial model.
   Never skip this step. The cost of a proper beneficiation test is tiny compared to the cost of building the wrong plant.

How to Balance Initial Investment (CAPEX) vs. Operating Cost (OPEX)?

When evaluating equipment proposals, the cheapest option is rarely the best. You must consider the total cost of ownership.

• DMS Circuit Example: Adding a DMS circuit to a spodumene plant increases the initial investment (CAPEX). However, by rejecting 40% of the ore early, it allows you to build a much smaller (and cheaper) grinding and flotation circuit. The daily savings on grinding power and flotation reagents (OPEX) are massive and can lead to a payback period of less than a year.
• Automated Reagent System: A basic, manual reagent system is cheap. A fully automated, high-precision system costs more upfront. But the automated system will provide stable, optimal dosing 24/7, increasing your average recovery and reducing reagent waste. This consistent performance improvement is a huge OPEX advantage.
  Always ask your equipment supplier to provide not just a price, but an analysis of the operational impact of their proposed solution.

Conclusion and Recommendation

The path to a successful lithium processing plant is paved with data. It begins with a deep understanding of your ore’s specific characteristics and ends with equipment selected to execute a process validated by thorough testing. There are no shortcuts.

1. Start with Mineralogy: Know your ore before you do anything else.
2. Test Your Process: A full beneficiation test is your blueprint for success.
3. Select Equipment for the Flowsheet: Choose machines that fit the tested process, not the other way around.
4. Think Total Cost: Balance CAPEX and OPEX to optimize for long-term profitability.

About ZONEDING

At ZONEDING, we specialize in turning geological data into profitable operations. With over two decades of experience, we don’t just sell machines; we provide complete, customized solutions for lithium ore processing plants. We can guide you through the entire process, from initial beneficiation testing to the final equipment commissioning.
If you are planning a lithium project, don’t leave your success to chance. Contact our team of engineers today to discuss your ore and let us help you design a plant that is robust, efficient, and profitable.