Boron One Holdings has completed metallurgical testing at its Piskanja boron project in Serbia, producing commercial-grade colemanite concentrate from representative run-of-mine material as the company prepares to resubmit the project’s amended feasibility study to Serbian authorities.
The latest processing programme incorporated expected mining dilution from hanging-wall and footwall material surrounding the orebody. The approach was designed to more closely replicate feed conditions anticipated during future underground mining. Earlier testing had demonstrated that Piskanja mineralisation could produce an acceptable concentrate, but those programmes did not include the quantity of waste material expected to enter the processing circuit during commercial extraction. Boron One said the new test confirmed that commercial-grade concentrate could still be produced from the diluted feed. The company did not disclose a new concentrate grade.
Additional studies support feasibility documentation
The metallurgical programme is being combined with further studies covering tailings and mine backfill, following requests from Serbia’s Mining Ministry during its review of the project’s Serbian-compliant feasibility study. Boron One temporarily suspended the ministry’s review while completing the additional technical work. The company plans to resubmit the amended documentation once the studies have been incorporated.
The next major regulatory milestone is approval of the project’s Exploitation Field, which would establish the area in which mining operations could be developed. Testing diluted run-of-mine-style material addresses a technical consideration associated with underground mining, where waste rock from the hanging wall and footwall can enter the ore stream and lower the grade delivered for processing. The latest work provides a more representative assessment of processing performance than tests based on selectively prepared mineralised material. Further engineering and scale-up work will still be required before the processing flowsheet can be demonstrated under commercial operating conditions.
Piskanja targets European borate supply
Located near Baljevac na Ibru in central Serbia, Piskanja contains colemanite, a calcium borate mineral used in glass, ceramics, fertilisers, insulation and speciality chemicals.
The project could provide an additional European source of borates in a market where global production is concentrated, particularly in Turkey.
Piskanja’s commercial development remains dependent on development costs, processing performance, permitting and the ability to secure customers. Boron products are predominantly sold through direct commercial relationships rather than liquid commodity exchanges, placing importance on concentrate specifications, customer qualification and logistics. Serbia’s location relative to industrial markets in Central and Southeastern Europe could provide a logistical advantage if the project advances to production.
Tailings and backfill studies feed into mine planning
The additional tailings and backfill studies will contribute to the proposed mine design and environmental documentation. Underground backfill can improve ground stability and reduce the quantity of material requiring surface storage, while also affecting operating costs and mine sequencing. With the metallurgical programme completed, Piskanja is progressing from resource and processing studies toward permitting, customer qualification and financing.
The project’s potential role as a European boron source does not eliminate market exposure. Global supply remains concentrated in Turkey, where established producers have scale, existing processing infrastructure and long-standing customer relationships. Boron products are also primarily sold through negotiated contracts rather than transparent exchange markets. New producers therefore need to meet specific product requirements and secure buyers at prices capable of supporting project development.
Regulatory approval and financing remain outstanding
For investors, the latest processing result reduces an identified technical uncertainty, while the remaining development considerations include regulatory approval, development costs, customer commitments and financing. Boron One has not disclosed a new concentrate grade from the latest test, and the Piskanja project still requires regulatory approval, additional engineering and financing before construction can begin.
The successful processing of diluted run-of-mine-style material represents further technical progress, while the project remains a pre-construction asset exposed to permitting, financing and market-access requirements. The next development milestones are linked to securing approval of the Exploitation Field, establishing bankable customer commitments and demonstrating production costs that support the project’s development economics.
