Review and interesting facts

One of the most interesting facts about Dysprosium and probably other REE, the element itself is one the most significant drivers for illegal mining. I find it very insightful how Dy mining and even leaching grows while it is not legally established. The research “Supporting Information for Uncovering the key features of dysprosium flows and stocks in China” Shijiang Xiaoa, Yong Genga. The Dysprosium mining established clear and sustainable growth. Dysprosium illegal mining according to some news channels varies up to 3 000 – 5 000 tonnes per year (USA production 400 tonnes).

What is dysprosium? The simple answer is the magnet that is built in many residential and commercial appliances and wearable devices.

Alloys:

  • Dy-Fe Alloys: Used in high-performance magnets.
  • Dy-Nd-Fe-B Magnets: Enhanced permanent magnets for electric vehicles and renewable energy.
  • Dy-Co Alloys: High-temperature magnets for aerospace and military use.
  • Dy-Ti Alloys: Improve strength and heat resistance in aerospace applications.
  • Dy-Mg Alloys: Enhance mechanical properties in automotive and aerospace industries.

Intermetallic Compounds:

  • Dy-Ni Intermetallics: Used in high-performance magnets.
  • Dy-Al Alloys: Strengthen materials for high-temperature applications.

Dysprosium-based Magnets:

  • Dy-Nd-Fe-B Magnets: High-performance magnets with improved thermal stability.
  • Dy-Fe-Co Magnets: Used in high-performance applications with superior thermal stability.

Compounds:

  • DyF₃ and DyCl₃: Used in production and neutron-absorbing materials.
  • Dy₂(SO₄)₃: Utilized in extraction and purification.

Nuclear Applications:

  • Dy Alloys for Nuclear Reactors: Used in neutron-absorbing materials for nuclear control rods.

Many publications like – “A critical review on solvent extraction of rare earths from aqueous solutions” Feng Xie, Ting An Zhang described the final products applications and as a result the streams for the refining.

For the market, mining and recycling strategies – “Unlocking Dysprosium Constraints for China’s 1.5 °C Climate Target” The trend to recycling the material is very clear.  The key drivers are transportation and alternative power generation.

Market insights and trends

One the best explanations for the Dysprosium life cycles is shown on paper “Tracing the multiregional evolution of the global dysprosium demand-supply chain”  Disna Eheliyagoda, Devarajan Ramanujan.

Insights

  • Dysprosium is mostly produced and consumed on China mainland
  • The recycling amount in extremely low
  • The main application for the element are all effectively recyclable

The product list which in crucial to be collected and recycled for Dysprosium are CR: computer, MP: mobile phone, WT: wind turbine, RF: refrigerator, AC: air conditioner, WM: washing machine, EB: ebike, EV: electric vehicle, HST: high-speed train, ICE: internal combustion engine vehicle; IR: industrial robot, MRI: magnetic resonance imaging machine, and ESE: elevator

Insight

Yes, China dominated on Dysprosium mining and production and also it consumes it a lot, because of the leader in appliances and compounders manufacturing. I changed my opinion for mechanical separation, due to the ability to lose 98% of the REE. One can say lose and other can say recover. It depends on the point of view. The one the best sources could be considered the dust waste that is typically neutralized.  The diagrams of the element presence on different markets prove the idea. The selective REE extraction might be one of the best trends in metallurgy for the decades upfront.

In paper “Review of critical metal dynamics to 2050 for 48 elements” Takuma Wataria,b, *, Keisuke Nansaia,c , Kenichi Nakajimaa. The Dysprosium is described as one most rapidly growing element to fuel economic growth. Critical metals are essential for new technologies, but their supply could be unstable. To manage this, we need to plan for their long-term demand and availability. A review of 88 studies on 48 critical metals shows that some metals lack long-term demand forecasts. Many studies also ignore the social and environmental impacts of growing demand and the differences between countries that produce and consume these metals. Additionally, while recycling is a focus, strategies like reusing components and remanufacturing are often neglected. These gaps highlight the need for more research on the future of critical metals to support sustainability and global development goals.

Personal opinion for the recycling

The Dysprosium materials are landed in electronic waste mostly.

  • Dysprosium-Iron (Dy-Fe) Alloys
  • Dysprosium-Neodymium-Iron-Boron (Dy-Nd-Fe-B) Magnets
  • Dysprosium-Cobalt (Dy-Co) Alloys
  • Dysprosium-Based Magnets (Dy-Fe-Co)
  • Dysprosium-Titanium (Dy-Ti) Alloys
  • Dysprosium-Magnesium (Dy-Mg) Alloys
  • Dysprosium Alloys for Nuclear Reactors
  • Dysprosium for High-Temperature Superconductors

The dysprosium streams will grow by growing the physical metallurgy – shredders, hammer crushers and gravity separators.

Mining and leaching

Rare earth elements are crucial for many high-tech products due to their unique properties. The main sources of rare earths are minerals like bastnäsite, monazite, and xenotime. These minerals are processed through flotation, gravity, or magnetic methods to produce concentrates, which are then treated with acids like HCl, H₂SO₄, or HNO₃. Solvent extraction is used to separate the rare earths, with various extractants like D2EHPA, HEHEHP, and Aliquat 336 being commonly used. The process may involve many stages to achieve the required separations, balancing cost and technical needs.

“A critical review on solvent extraction of rare earths from aqueous solutions Feng Xie, Ting An Zhang”

Recycling / Refining

The challenge for the element itself is not well established understanding for the electronic waste recycling. Traditionally the electronic waste recycling lines are built to effectively recover the plastic, copper, gold, silver, platinum and palladium. Recent research proved the significant losses for all REE that urban mines contain. The hammer crusher itself is the best recovery tool for the REE from the PCB boards.

“Separation Efficiency of Valuable and Critical Metals in WEEE Mechanical Treatments”

Hydrometallurgy

My best recommendation is to read the papers of the Solvomet research group. I find them one of the best on the hydrometallurgy research

“The separation of rare-earth elements (REEs) is considered one of the most challenging processes in solvent extraction. In recent years, non-aqueous solvent extraction, a unit operation within solvometallurgy, has stepped into the limelight as one of the promising techniques for efficient REEs separation. In this paper, a rare-earth hydroxide concentrate, originating from mining waste and containing mainly heavy rare-earth elements (HREEs), was redissolved in ethylene glycol + 10 vol% water, 0.43 mol L− 1 HCl and 0.8 mol L− 1 NaCl. Based on batch experiments, a conceptual flowsheet was proposed for the separation of the HREEs into 2 groups: a thulium group (Tm, Yb and Lu) and a dysprosium group (Dy, Ho, Er and Y). Continuous solvent extraction tests in labscale mixer-settlers were performed to confirm the technical feasibility of the developed system, as well as to identify and resolve possible bottleneck points. Eventually, using only 16 stages of lab-scale mixer-settlers, the purity of the thulium group and dysprosium group elements, originally 34% and 54%, respectively, reached 99.8% and 98.7%, respectively. Further optimization remains necessary for the separation and purification into highly pure single REEs”

Many other research was done to get the process parameters for the selective rare earth hydrometallurgy. “Novel closed-loop recovery of light rare earth elements, as their oxides, from end-of-life mobile phone speakers using [Hbet][Tf2N]” Moises Gomez, Sue Grimes. I like the research showing the amount of the metals that needed to be separated. Almost all elements could be found in new waste streams at comparable concentrations.

The growing demand for rare earth elements (REEs), driven by economic growth and green technologies, has caused supply instability, mainly due to China’s dominance in production. Sourcing REEs from secondary sources, like End-of-Life Mobile Phones (EoL-MPs), is essential. A new hydrometallurgical process using the ionic liquid [Hbet][Tf2N] for leaching REEs from EoL-MPs has been developed. This process efficiently recovers light REEs (Nd, Pr) with over 90% efficiency and purity ≥ 98%, while retaining heavy REEs (Dy, Tb) in the residue for potential recovery. The process is sustainable, generates minimal waste, and allows the ionic liquid to be reused up to five cycles.

Metal – Metal leaching

“Rare Earth Magnet Recycling Via Liquid Magnesium Leaching and Distillation”

“Liquid Metal Leaching for Rare Earth Magnet Recycling Emmanuel Opoku , Chinenye Chinwego”

Numerous studies have explored the magnet-to-metal process, where rare earth elements like neodymium, praseodymium, dysprosium, and terbium are extracted from magnets using molten metals. These recycled elements can then be used to create new rare earth magnets, offering a more sustainable and eco-friendly supply. This research outlines the steps involved in this recycling process, which begins with demagnetization and the removal of coatings. Leaching is carried out using liquid magnesium and bismuth, and the process is enhanced through a continuous gravity-driven multiple effect thermal system (G-METS) for distillation. The G-METS method could potentially increase the efficiency of rare earth metal extraction, contributing to the development of a more sustainable supply chain for rare earth magnets.

Deep purification

Yes, the vacuum metallurgy works. My point. The idea is correct and it could be continuous by vacuum metallurgy. What are the impurities and its segregation coefficient in specific rare earth? Is that the big challenge to purify 98% till 99,99% or it is just the matter of the 5-10 passes by crystallization. Yes, the thermal conductivity and density work best for the zone refining, and the melting point is ok for the many advanced materials to build the crucible.

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My favorite point is to compare the market for the base purity elements and compare it with new future markets that require the high purity base element, starting 99,999%. Dysprosium high purity is projected as a winner.

The thermal physical properties and refining atmosphere required for the Dysprosium deep purification is good for the floating zone, direct solidification and even zone melting to be applied

My point is the Vertical Gradient Freeze (VGF) could be the best to work with the metal, However I will left a room for the solvent leaching for the high soluble impurities

The process for the deep purification was developed many years ago and  I assume could be the base for the development of new technologies.

THE LAST AND THE MOST IMPORTANT,

DYSPROSIUM IS CRITICAL 2040 OR NOT? (MY PERSONAL OPINION ONLY)

My answer – Dysprosium is a significant part of the future in many areas in which nobody shares technologies.

To answer the question all supply and materials production chains needed to be reviewed. The material itself required the leaching, selective refining, vacuum deep purification and compound synthesis. Technologically there are too many gaps that need to be closed by the new technologies to fulfill the supply chain.  The market for the Dy based materials is many times higher than Dy base grade 90-99%. The rare earth elements, unlike others, require separate 5-30 elements and then purify the element which is very active and then synthesize the new material. It is hard to mark the element that the game changes because too many unique elements are applied to make a single component. ChatGPT search for Dy material and artificial precious stones droppings

Dysprosium economy seems suitable for the high tech refinery