Boron One Holdings said it had produced commercial-grade colemanite concentrate from representative run-of-mine material at its Piskanja boron project in Serbia, completing a key technical test ahead of the resubmission of the project’s feasibility study to Serbian authorities.
The metallurgical programme included expected mining dilution from hanging-wall and footwall material surrounding the orebody, making the feed more representative of conditions expected during future underground operations.
Earlier tests had shown that Piskanja mineralisation could produce an acceptable concentrate but did not include the level of waste material expected to be extracted with the ore during commercial mining.
Boron One said the latest work showed that commercial-grade concentrate could still be produced from the diluted feed. It did not disclose a new concentrate grade.
The metallurgical work, together with additional studies on tailings and mine backfill, forms part of amendments requested by Serbia’s Mining Ministry during its review of the project’s Serbian-compliant feasibility study.
The company temporarily suspended the ministry’s review while completing the additional work and plans to resubmit the amended documentation once the studies are incorporated.
The next major regulatory step is approval of the project’s Exploitation Field, which would define the area within which mining operations could be developed.
The processing result addresses one of the technical risks facing Piskanja because dilution can reduce the grade of material delivered to a plant and affect concentrate quality and recoveries.
Waste rock extracted with ore is common in underground mining, meaning test work using representative diluted material provides a closer indication of potential operating performance than processing selectively prepared mineralised samples.
Further engineering and scale-up work will be required before the process can be demonstrated under commercial conditions.
Piskanja, near Baljevac na Ibru in central Serbia, 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.
That concentration has increased interest in alternative supply, although Piskanja’s commercial viability will depend primarily on development costs, processing performance, permitting and its ability to secure customers.
Boron products are largely sold through direct commercial relationships rather than liquid commodity exchanges, making concentrate specifications, customer qualification and logistics important to project economics and financing.
Serbia’s proximity to industrial markets in Central and Southeastern Europe could provide a logistical advantage if the project reaches production.
The additional tailings and backfill studies will feed into the proposed mine design and environmental documentation. Underground backfill can improve ground stability and reduce material requiring surface storage, but can also affect operating costs and mine sequencing.
With the latest metallurgical work completed, Piskanja is moving from resource and processing work toward permitting, customer qualification and financing.
The project’s position as a potential European boron source does not remove its market risk. Global supply remains concentrated in Turkey, where established producers benefit from scale, existing processing capacity and long-standing customer relationships.
Boron is also largely sold through negotiated contracts rather than a transparent exchange market, leaving new projects dependent on their ability to meet precise product specifications and secure buyers at prices that support development economics.
For investors, that changes the nature of the Piskanja risk profile. Further technical progress can support the project, but the larger potential valuation catalysts are now regulatory approval, credible development costs, customer commitments and evidence that the project can be financed.
Boron One has not disclosed a new concentrate grade from the latest test, while Piskanja still requires regulatory approval, further engineering and financing before construction can begin.
The successful treatment of diluted run-of-mine-style material removes an important technical uncertainty, but Piskanja remains a pre-construction asset exposed to permitting, financing and market-access risk.
The next potential value inflection will depend on whether Boron One can turn the latest technical progress into an approved exploitation area, bankable offtake and competitive production costs.
