Rare Earth News Bi-Weekly Patent Bulletin

Dr Michelle Lynch

Week Commencing 8Th February 2021 – with updated criteria applied back to 1st January 2021.

Welcome to this week’s rare earths patents update. To our friends in China – Happy New Year of the Ox!

The search approach adopted to generate the results has been changed since last time to focus more on the production of the magnetic powders and the magnet materials rather than their applications. The search has been dated back to the start of the year and a new historic spreadsheet provided. A total of 116 patents were returned after the search was performed and less relevant results removed. The majority (108) were filed in China and the remainder that appeared came from Japan, Korea, Russia or were international applications filed through the World Intellectual Property Organisation (WIPO). See below this article for the full excel spreadsheet.

The assignees are a broad church around 80 separate company names after some light company name grouping has been performed. Six assignees have more than two patent publications, some other assignees are specifically looking at reducing raw material demand by adding in recycled materials. These assignees technology areas are summarized in Table 1. below.

When reading the patent – the reason for the invention i.e., the problem to be solved can be gleaned from the patent description and this is just as important to understand as the methods claimed. Patent analysis can take the “5WH” approach –           Who?, What?, Where?, When?, Why?, and How? – in order to extract the deepest view of the landscape. Just reading a few patents in the field of rare earth magnet preparation reveals some interesting reasons for inventions including the need for more accurate product design, yield, corrosion inhibition, higher process intensification and lower costs, reduced virgin rare earth requirements via recycling and increased magnetic force.

The one USA patent in the search set (US2021036387 AA) was filed by Iowa State University, based in Ames, Iowa, USA, on chemical recycling of rare earth elements (REE) from neodymium-iron-boron (NdFeB) magnets and lithium-ion batteries (LIB). The research for the invention was sponsored under Contract No. DE-ACO2-07CH11358 awarded by the U.S. Department of Energy. The government has certain rights in the invention. The patent description contains the “Why?” – because current recycling methods use strong acids that generate toxic fumes and effluents which lower the commercial recycling prospects and result in a high proportion of rare earth and battery materials going to landfill. The method claimed (“How?”) involves the use of scalable, cost-efficient stages whereby ammonium and iron salts are utilised which can be reclaimed and reused. The iron can be added anhydrously as iron(III)chloride (FeCl3) or ammonium chloride (NH4Cl) and ball milled with the spent magnets. After boiling and filtration, anhydrous sodium sulphate is used to precipitate out the neodymium as NaNd(SO4)2·H2O. Yields of between 80-90% were obtained. Notably in another example hydrochloric acid was employed for a magnet scrap material (MSM) and NaNd0.85 Pr 0.15(SO4)2·H2O was oofbtained and in other examples the approach was applied to samarium-cobalt (SmCo) spent magnets to give a precipitate of NaSm(SO4)2·H2O.

That is all for this edition. Check back for the next edition in two-weeks’ from now, when I will take a deep dive into the International Patent Classification (IPC) code system and explain how these are highly useful when it comes to analysing and comparing patent search sets. 

Table 1. Top Assignees for Production and Recycling of Permanent Rare-Earth Magnets (2021)

NEW MATERIAL TECHNOLOGY CO LTD JIANGSU HASH MAGNETIC6Rare earths processing equipment – grinders, wire cutting, sintering furnace, auxiliary jigs and processing machines. Problems solved include avoiding equipment shaking, temperature uniformity in sintering ovens which reduces accuracy and yield. 
MAGNETIC TECHNOLOGY CO LTD3Air- and water-cooling systems for NdFeB magnets after a hydrogen treatment stage. Inventions shorten the mixing time and improve mixing efficiency, prevent weld cracking etc.
BAOTOU YINGSTEDT DILUTE MAGNETIC MATERIAL CO LTD3Rapid identification marking for NdFeB magnets and packing systems
NINGBO FORCE MAGNETIC MATERIAL TECHNOLOGY CO LTD3Cerium containing NdFeB magnet compositions prepared using waste magnet material and Cu, Al, B, Co, Ce, Zr, Ga, Tb, La, Bi and Fe. Th in the formulation. Bi is added for grain refinement, thus ensuring ndfeb magnetic coercive force does not drop. The method reduces the amount of Nd and Pr needed. Also patents on addition of organic anti-corrosion inhibitors (“alkylene ball”)
JIANGSU UNIV  3Scalable, timesaving, energy-saving monodisperse magnetic adsorbent MMSS manufacturing method. Achieved using a new mixing high internal phase emulsion HIPES method to make a NdFeB magnet.   Composite NdFeB/Al alloy magnet with lightweight, good strength, toughness and much higher conductivity.    Dysprosium-based single-ion magnet material prepared according to a safe and simple process with high controllability, good reproducibility, high product purity and yield are high at room temperature conditions.  
JIANGXI FLUORESCENCE MAGNETIC IND CO3NdFeB processing vacuum sintering furnace with faster sintering speed and accuracy; an automatic pressured molding device and a supplementary angle pressure-type device with moving plates for higher accuracy supplementary angles. Used for making special shapes e.g., for medical devices.
NINGBO KETIAN MAGNET CO LTD1Utilization of recycled materials for preparing a high-performance ndfeb magnet, reducing the re-melt, homogenization step, and by adding a small amount of the rare earth component modifier.
INSTITUTE FOR ADVANCED ENGINEERING1Improved grinding process for NdFeB magnet recycling with high hardness by a heat-treatment to cause micro-cracks in the structure.
IOWA STATE UNIV1Use of iron(III)chloride and ammonium chloride for recovering rare earth elements from spent permanent magnets and battery materials.

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