- project name : VORTEX Gold North Macedonia
- project number: CIR_250668726
- project start: dec 2025
- project manager: Jürgen Dahnke
I. Project Overview
This 24-month CIRAS-funded research project focuses on the optimization of vortex plasma mills and acoustic resonance sorting systems for sustainable, chemical-free gold extraction from North Macedonian gold ore and mine tailings.
The project will design, construct, and validate a multi-stage sorting and vortex-milling platform capable of:
- Separating gold-bearing minerals from heterogeneous ore and tailing mixtures.
- Refining micron-scale gold powders (<10 µm) with <0.1% impurities.
- Operating without mercury, cyanide, or water, achieving a zero-pollution extraction process.
By integrating AI-driven sorting, plasma-vortex separation, and resonant dust selection, this initiative will position North Macedonia as the European leader in next-generation, clean gold mining.
II. Background
Gold mining in North Macedonia and surrounding Balkan regions generates significant quantities of tailings rich in residual gold, trapped within quartz, sulfides, and silicates. Traditional recovery techniques rely on toxic leaching and high water consumption, producing long-term soil and water contamination.
CIRAS proposes a plasma-based alternative:
- Vortex mills employ high-pressure air or plasma vortices (10⁵–10⁶ Pa) to pulverize mineral aggregates.
- Electromagnetic resonance fields disintegrate ore at the atomic level, liberating metallic gold particles.
- Acoustic resonance tubes downstream isolate ultra-fine gold dust fractions (<10 µm) for precision refinement and reuse.
The resulting fine, pure powders are ideal for:
- Recasting and refining into bullion.
- Additive manufacturing of conductive gold microstructures (e.g., sensors, coatings, jewelry, and connectors).
- On-site remanufacturing, transforming waste tailings into high-value materials.
III. Objectives
- Develop an Advanced Gold Sorting Mechanism
- Multi-stage preprocessing of gold ore and tailings.
- Separate quartz, sulfides, and metallic fractions via density and magnetic differentiation.
- Target recovery > 95% of gold-bearing material, contamination < 2%.
- Optimize the Vortex Milling System
- Tune plasma-vortex parameters (pressure, magnetic density, rotation rate).
- Achieve gold particle size d₅₀ = 5–10 µm, purity ≥ 99.9%.
- Integrate Resonance Tube Refinement
- Acoustic resonance tubes (1–10 kHz) to select fine gold dust and remove quartz fines.
- Enhance yield of fine metallic fractions < 10 µm.
- Validate Extraction and Refinement Efficiency
- Demonstrate >30% higher gold recovery from tailings compared with gravity or flotation.
- Characterize powders for purity, morphology, and reusability in gold alloy manufacturing.
- Assess Sustainability and Economic Performance
- Prove zero-water, zero-acid operation.
- Achieve > 20% energy savings vs. conventional grinding.
- Conduct LCA and cost-benefit analysis for industrial adoption.
IV. Methodology
Phase 1 — System Design and Development (Months 1–6)
Task 1.1 — Ore and Tailings Characterization
- Collect samples from North Macedonian gold deposits and legacy tailings.
- Analyze mineral composition via XRF, XRD, and SEM.
- Typical composition: 60% quartz, 20% sulfides, 5–10% gold and associated heavy metals.
Task 1.2 — Sorting Mechanism Design
Develop a four-stage dry separation system:
- Vibrating screens (mesh 1 mm → 100 µm) to classify grain sizes.
- Magnetic separators to remove magnetite and ferrous contaminants (>95% efficiency).
- Air-density classifiers to distinguish quartz and gold particles by mass (quartz 2.65 g/cm³ vs gold 19.32 g/cm³).
- Cyclonic pre-cleaners for dust control and feed consistency.
Goal: produce a clean, uniform gold-bearing feed for the vortex mill.
Task 1.3 — Resonance Tube Design
- Stainless-steel tubes (0.5–1 m length, Ø 10–20 cm) with piezoelectric transducers.
- Simulate standing-wave fields (COMSOL Multiphysics) at 2–8 kHz for particle sorting.
- Tune acoustic nodes to concentrate gold dust (<10 µm) at specific resonance frequencies.
Task 1.4 — System Integration
- Combine sorting modules, vortex mill prototype, and resonance tubes.
- Implement Python-based control interface for real-time monitoring of particle size, flow, and resonance tuning.
Deliverables:
- Material characterization report.
- Prototype designs for sorter, vortex, and resonance units.
- Integrated control software.
Phase 2 — Gold Ore Processing and Testing (Months 7–14)
Task 2.1 — Sorting and Feed Preparation
- Process 200 kg of gold ore/tailings.
- Evaluate recovery (>95%) and contamination (<2%).
Task 2.2 — Vortex Milling Trials
- Operate mill at pressures 10⁵–10⁶ Pa and rotation > 20,000 rpm.
- Measure output:
- Gold particle d₅₀ = 5–10 µm.
- Energy < 70 kWh/ton.
- Purity ≥ 99.9%.
Task 2.3 — Resonant Dust Selection
- Pass vortex output through resonance tubes.
- Isolate ultra-fine gold dust (<10 µm).
- Measure efficiency via laser diffraction and SEM imaging.
Task 2.4 — Powder Characterization
- Analyze gold powders for:
- Particle size (d₅₀, d₈₀).
- Purity (EDS, ICP-MS).
- Surface area (BET 15–20 m²/g).
- Morphology and uniformity (XRD, SEM).
Task 2.5 — Refining and Recasting Trials
- Smelt isolated gold powder into 99.99% bullion using induction furnace.
- Compare recovery rate and energy use to traditional cyanide leaching.
Deliverables:
- Gold powder dataset.
- Extraction performance report.
- Energy and purity analysis.
Phase 3 — Optimization and Field Validation (Months 15–20)
Task 3.1 — Sorting Optimization
- Adjust classifier airflows and magnetic field intensity for > 98% gold recovery.
- Energy consumption < 5 kWh/ton.
Task 3.2 — Resonance Tube Calibration
- Tune frequency range 1–10 kHz for optimal dust selectivity.
- Maintain < 2% clogging at 1 ton/hour throughput.
Task 3.3 — Comparative Efficiency Analysis
- Compare optimized vortex + resonance system to:
- Gravity separation, flotation, and cyanidation processes.
- Target ≥ 30% improvement in gold recovery and ≥ 90% reduction in environmental impact.
Task 3.4 — Pilot Demonstration
- Deploy pilot unit at an active Macedonian gold mine tailing site.
- Demonstrate 1 ton/hour continuous operation.
- Measure gold yield, energy use, and residual waste toxicity reduction.
Deliverables:
- Optimized process protocols.
- Pilot test report and performance metrics.
Phase 4 — Sustainability and Impact Assessment (Months 21–24)
Task 4.1 — Environmental Impact Assessment
- ISO 14040 LCA comparing to cyanide leaching and wet grinding:
- Water use: 0 L/kg vs 10–20 L/kg.
- CO₂ reduction: 20–30%.
- Waste reduction: ≥ 50%.
Task 4.2 — Economic and Operational Analysis
- Capital cost: ≈ $80,000 (prototype system).
- Operating cost: $8–12/ton.
- Target return on investment in < 2 years for mine operators.
Task 4.3 — Dissemination
- Publish in Journal of Sustainable Mining and Minerals Engineering.
- Present results at TMS 2026 and the CIRAS Sustainability Forum.
- Develop a CIRAS policy brief on Waterless Gold Mining Innovation.
Deliverables:
- Environmental and economic reports.
- Peer-reviewed papers and policy brief.
V. Critical Path and Milestones
| Milestone | Timeline | Output |
|---|---|---|
| Month 6 | Integrated prototype (sorting + vortex + resonance) | Functional system |
| Month 14 | Validated powder quality and gold purity | Technical dataset |
| Month 20 | Optimized process and pilot field results | Industrial validation |
| Month 24 | LCA and economic assessment completed | Final reports and publications |
VI. Expected Outcomes
| Category | Target Achievement |
|---|---|
| System Output | Integrated dry processing system for gold ore and tailings |
| Gold Powder Quality | d₅₀ = 5–10 µm; purity ≥ 99.9%; surface area 15–20 m²/g |
| Recovery Efficiency | ≥ 95% gold capture from ore and tailings |
| Energy Efficiency | < 70 kWh/ton grinding; < 5 kWh/ton sorting |
| Environmental Performance | 100% water elimination; ≥ 50% CO₂ reduction |
| Pilot Validation | Continuous 1 ton/hour operation at field site |
| Dissemination | CIRAS report + international publications |
VII. Risks and Mitigation
| Risk | Probability | Impact | Mitigation |
|---|---|---|---|
| Ore composition variability | High | High | Adaptive sorting parameters; multi-site sampling |
| Resonance tube clogging | Medium | Moderate | Vibration-assisted design and cleaning cycles |
| High initial equipment cost | Medium | Moderate | Modular scale-up and co-funding through industry partners |
| Plasma instability during vortex operation | Medium | Moderate | AI feedback control and pressure stabilization |
| Adoption barriers in mining sector | Medium | High | Pilot demonstrations and training for mine operators |
VIII. Environmental and Societal Impact
- Zero-pollution gold recovery: no mercury, no cyanide, no tailing leachate.
- Water conservation: fully dry mechanical and plasma process.
- Tailings rehabilitation: conversion of mine waste into inert fine powders.
- Local economic growth: creation of green mining jobs and technology exports.
The project directly supports UN SDGs 6, 9, 12 and 13 (Clean Water, Industry Innovation, Responsible Consumption, Climate Action) and the EU Green Deal objectives.
IX. Conclusion
This CIRAS initiative will establish the first integrated, zero-chemical gold extraction platform using vortex plasma and resonance-acoustic refinement.
By focusing exclusively on gold mine materials, the project bridges advanced physics, AI control, and sustainable engineering, creating a closed-loop resource recovery system that turns waste into high-value gold powders.
Upon completion, North Macedonia will host Europe’s first waterless, plasma-based gold extraction pilot, positioning the country as a global model for eco-intelligent mining and setting new standards for the future of resource sustainability.