Core Viewpoint - Japan has implemented a long-term strategy to block rare earth supply from China, which has led to significant advancements in patent applications related to rare earth processing technologies, creating barriers for Chinese researchers to overcome [1][3]. Group 1: Japan's Strategy and Patent Applications - In 2008, Japan's "Critical Minerals White Paper" emphasized the need to decouple rare earth supply from China [1]. - From 2011 to 2014, Japan filed a total of 2,384 patents related to rare earth processing, surpassing the total of all other countries combined [3]. - The patents were designed to be opaque, providing only framework information without critical parameters, making practical application difficult [3][5]. Group 2: Chinese Research Response - In 2014, the Chinese Academy of Sciences initiated a "patent reverse engineering plan" to analyze Japanese patents, focusing on key companies like Sumitomo Chemical and Hitachi Metals [5]. - The research team identified that 92% of the patents had missing critical parameters while maintaining complete reaction pathways [5][6]. - The team aimed to exploit these gaps, leading to the establishment of a testing site in Inner Mongolia in 2015, where they attempted to replicate Japanese processes using modified equipment [8]. Group 3: Breakthroughs and Results - The Chinese research team conducted extensive experiments, including 412 tests on pH adjustments, despite facing numerous failures [9][11]. - A breakthrough occurred when the team deduced a temperature control method from the patents, allowing them to replicate the Japanese processing route without original data [12]. - By 2021, the technology was successfully industrialized, achieving a dysprosium purity of 99.5% and a recovery rate exceeding 80% [13][19]. Group 4: Historical Context and Market Dynamics - From 1990 to 2010, China's rare earth export share decreased by 30%, while Japan's patent filings continued to grow, creating a significant technological barrier [15][17]. - The WTO dispute in 2012 resulted in China losing its export quota, allowing Japan to expand its control and invest in alternative production lines in other countries [17]. - The technological deadlock was characterized by a lack of critical parameters and understanding of processing paths, but the Chinese research community's persistence led to eventual breakthroughs [19].