The waste is a pure silicon core wrapped in an oxide shell
1 / 8
Slicing an ingot into wafers throws away about a third of the silicon. CEA puts the loss at 35% of ingot mass, and it leaves the saw as powder a couple of microns across, with a median particle size near 1.6 µm and 30.4 m² of surface per gram.
The only committed capital in the field is a tariff bet in Tennessee
2 / 8
Every other project here is a pilot or a project report. Highland Materials is the single announced build with a balance sheet behind it, and its numbers are large enough to reset what commercial scale means in this field: 16,000 tonnes a year of solar-grade polysilicon initially, ramping to 24,000 tonnes, on a brownfield site at Phipps Bend, Tennessee.
Strategy
The published work comes from one European consortium, and the wave is its closing
3 / 8
Almost all of the research literature this field has produced in the last two years traces to ICARUS, a project of eighteen European partners running four pilot lines, which ended in November 2025. The output arrived in a burst rather than a trickle: the carbothermic kerf-and-pot-scrap paper at SiliconPV in December 2025, SINTEF's own record of the same campaigns in March 2026, and the consortium's summary paper in April 2026.
Research
Four pilot modules were built, and their capacities describe different plants
4 / 8
A European project called ICARUS ran four processing lines and reports each one's rating. Read together, they do not form a plant.
Market
The price it has to beat has rebounded, and it is still short
5 / 8
The commodity the recycled product displaces has moved back up. Chinese N-type dense polysilicon was quoted at RMB 41.44 per kilogram in November 2026, roughly 5.8 dollars, after trading near RMB 32.3 per kilogram, about 4.75 dollars, in July. Inventory above 570,000 tonnes and November output near 95,000 tonnes keep the recovery fragile.
Strategy
The organisations that proved the process hold almost none of the patents
6 / 8
The patent record in this field is Chinese and Korean, plus one early family from Total and SunPower. None of SINTEF, ReSiTec, LuxChemtech or Norsun holds a family. ROSI is the exception among the European pilot partners, with families filed in six to eight jurisdictions, including a dilute hydrogen peroxide wash for kerf slurry and a granulation route filed in France and as a WO.
Research
Leaching clears the surface cheaply, and the melt is where silicon is lost
7 / 8
The standard sequence is an acid wash followed by a high-temperature step. In 1 M hydrochloric acid, 91% of the iron, 77% of the nickel and 75% of the phosphorus come out at ambient temperature. Adding an inductive melt raises removal to 99% iron, 92% phosphorus, 85% calcium, 79% nickel and 78% aluminium.
Market
What has actually been produced is drying, powder and metallurgical silicon
8 / 8
The outputs with tonnage behind them are narrow. A continuous dryer for kerf filter cake reached below 1% moisture at 876 to 2,600 tonnes a year, and the submerged arc campaigns produced silicon close to the traded grade metal silicon #553, quoted at 1,585 dollars per tonne, roughly 1.59 dollars per kilogram. The highest-purity output is ROSI's granule line at 4N, running at 1 kg/h.