Zangge Mining (Laos) Launches Research on Potassium Chloride Project Backfilling

On July 11, 2025, the kick-off meeting for the underground backfilling research of the Potassium Chloride Project of Zangge Mining (Laos) Development Co., Ltd. was grandly held. Attendees included Xiao Yao, President of Zangge Mining; Fu Yi, Deputy Chief Engineer of Zijin Group; representatives from Xiamen Zijin Mining & Metallurgy Technology Co., Ltd., Zijin Changsha Engineering Technology Co., Ltd., and Zijin Xiamen Design Co., Ltd.; Fu Feilong, General Manager of Zangge Laos, members of the company’s management team, and heads of relevant departments—over 30 participants in total. The meeting officially launched the technical research and development of cemented backfilling for potash mining.

The project is located in the southern part of Bokeo District, Vientiane, Laos, on the northern edge of the Vientiane Basin, endowed with world-class high-quality potash resources. According to the obtained Reserve Certificate, the exploration rights in Bokeo District cover approximately 157.72 square kilometers, with total potassium chloride resources of 984 million tons, demonstrating exceptional resource endowment. The Company plans to invest in the construction of the potassium chloride project using a strip-room-and-pillar mining method with subsequent cemented backfilling, where tail salts and magnesium slurry from brine evaporation will be mixed with cementing material and used to backfill underground mined-out areas. This process not only achieves balance between mining and backfilling, significantly improving resource utilization, but also reduces tailings discharge and environmental impact, laying a solid foundation for sustainable mine development.

As large-scale cemented backfilling of potash mines has not yet been successfully implemented in Asia, the project faces multiple technical challenges: the mining area is adjacent to the Mekong River, and ecological protection requirements prevent the construction of permanent tailings ponds, while surface environment protection and mined-out area treatment standards are strict. To address these challenges, Zangge Mining established a backfilling technical research leadership team led by Chairman Wu Jianhui, with a technical research team headed by Fu Yi, Deputy Chief Engineer of Zijin Group, to focus on overcoming key bottlenecks restricting project progress.

At the kick-off meeting, the teams identified four core research directions:

Develop low-cost cementing materials adapted to the characteristics of tail salts and brine, addressing current industry issues of high consumption, high cost, and insufficient strength of cementing materials. Optimize backfill strength design through theoretical calculations and numerical simulations, accurately determining technical parameters. Conduct systematic experimental research to fully understand the physical and chemical properties of tail salts and brine and their mixing rules. Formulate a scientific and comprehensive backfilling system process plan to provide solid technical support for subsequent construction. The entire research project aims to overcome the technical difficulties of potash mine cemented backfilling.

In his concluding remarks, President Xiao Yao emphasized that Zijin Group and Zangge Mining will provide comprehensive support for the research work. He urged all researchers: “With a strong sense of responsibility and mission, collaborate effectively, maintain an open and shared research attitude, leverage all technical advantages, and bravely explore uncharted technological areas.” He required the team to efficiently advance research tasks and ensure that outcomes are translated into practical applications as soon as possible, injecting core momentum for smooth project implementation.

The launch of this technical research marks a key step for Zangge Mining in the green development of potash resources, and will provide pioneering practical experience in backfilling technology for Asian potash mines, with far-reaching significance for promoting technological advancement in the industry.