Series: Mining & Materials • Part 9
Glass & Stone — Solar Glass, Bricks & Bindings Without Smoke
We melt sand with sunlight and stack it into cities. No coal flames, no dusty chimneys — just quiet electric heat and recipes that turn rocks into windows, bricks, and binders that love our air.
Today’s mission
Melt solar glass in all‑electric furnaces, at scale.
Fire bricks & ceramics in electric kilns (or skip firing where we can).
Bind stone with low‑carbon cements and carbonation cures.
Why glass & stone (we build with geology)
Metals give us nerves and bones; glass and stone give us skin and shelter. These flows are huge — which is perfect, because our energy is huge (Part 3). We electrify the hot parts, recycle the solid parts, and design the plants to be good neighbors from day one.
- All‑electric heat (Joule/induction/resistance) replaces fossil flames.
- Closed water loops — air stays clear, cooling is quiet.
- Local sand & clay — ship panels and bricks, not raw dirt (Part 8).
Solar glass — clear, tough, and born of electrons
Process at a glance
- Batch: silica sand + soda ash + limestone + dolomite + cullet (recycled glass)
- All‑electric melter: molybdenum electrodes, Joule heat, low NOx by design
- Float/anneal: ribbon on tin bath, stress relieved
- Temper & AR coat: 3.2 mm low‑iron glass for PV (or 2×2.0 mm for bifacial)
Why all‑electric?
- Clean air: no combustion plume; filters capture the tiny stuff.
- Control: precise temperature fields → fewer defects, better yields.
- Energy loop: daytime PV drives melter; storage covers nights.
Textures & coatings for solar performance
Solar glass gets anti‑reflective (AR) nano‑coats and gentle textures that bend light into cells instead of the sky. It is transparent stubbornness — the panel’s shield and lens at once.
Bricks & ceramics — kilns without smoke
Two routes we like
- Electric tunnel kilns: pressed bricks, continuous flow, heat recovery to dryers
- Low‑temp binders: pressed blocks cured by steam or CO₂ (skip high‑temp firing)
Why it matters
- Firing is the last big dusty holdout; electrifying it cleans skylines.
- Materials stay local — we ship pallets of shape, not truckloads of moisture.
- Scrap brick re‑enters the body as aggregate; nothing goes to waste.
3D‑printed shapes?
Absolutely: clay and cementitious pastes print into arches, ribs, and ducts that traditional molds hate. We cure with heat pumps and electric ovens; the city becomes a kit of elegant parts.
Bindings without smoke — cements that behave
What we make
- LC³: limestone calcined clay cement — lower temp, lower CO₂, great performance
- CSA & belite blends: fast‑set options with reduced clinker
- Geopolymer lines: alkali‑activated slag/clay for precast and pavers
How we tame carbon
- Less clinker: more performance from clay + limestone, less decarbonation.
- CO₂ to product: we cure precast blocks in controlled CO₂, locking it in.
- Electrons for heat: kilns and dryers run on the same PV microgrid as the rest of campus.
Where does the CO₂ for curing come from?
From neighbors: electrolyzers (Part 4) concentrate gases; carbonate‑hardening shops sip this CO₂ and give it a job. The lake (Part 1) handles water, the microgrid handles electrons, and chemistry handles the rest.
Per‑ton cheat sheet (indicative, electricity only)
| Product | kWh per ton | Notes |
|---|---|---|
| Solar float glass (low‑iron) | ~1,200–1,800 | Melter + anneal + temper + coat |
| Container/flat glass (recycled‑rich) | ~800–1,300 | High cullet cuts energy |
| Fired bricks/tiles | ~800–1,600 | Drying + electric kiln |
| Pressed CO₂‑cured blocks | ~150–350 | No high‑temp firing |
| LC³ binder | ~350–650 | E‑calciner + grinding |
| Conventional OPC (e‑kiln) | ~700–1,100 | Higher temp & grinding |
Ranges reflect plant design, cullet %, moisture, and recovery. Use high end for planning; celebrate the low.
Glass thickness → mass (quick pick)
| Sheet | kg per m² | Use |
|---|---|---|
| 2.0 mm | ~5.0 | Rear glass (bifacial) |
| 3.2 mm | ~8.0 | Front solar glass (mono) |
| 4.0 mm | ~10.0 | Architectural |
From Part 3: ~5,000 m² glass/MWp ≈ ~50 t/MWp of modules (single‑glass).
Pre‑calculated plant scenarios
Solar glass campus
Line sizes are typical; we cluster lines for scale.
| Scale | Throughput | Avg elec load | PV min | 12 h storage |
|---|---|---|---|---|
| 1 line | ~700 t/day (~0.25 Mt/yr) | ~35–50 MW | ~180–260 MWp | ~210–300 MWh |
| 4 lines | ~2.8 kt/day (~1.0 Mt/yr) | ~140–200 MW | ~720–1,030 MWp | ~0.8–1.2 GWh |
PV “min” uses Avg(MW)×5.14 (5.5 PSH, 85% DC→AC). We oversize to feed neighbors (coaters, temper).
Bricks & blocks campus
| Scale | Throughput | Avg elec load | PV min | 12 h storage |
|---|---|---|---|---|
| Fired bricks | ~0.5 Mt/yr | ~25–40 MW | ~130–205 MWp | ~150–240 MWh |
| CO₂‑cured blocks | ~0.5 Mt/yr | ~5–10 MW | ~26–51 MWp | ~60–120 MWh |
Blocks skip high‑temp firing → massive energy savings, perfect for precast.
Binder (LC³) plant
| Scale | Throughput | Avg elec load | PV min | 12 h storage | Notes |
|---|---|---|---|---|---|
| LC³ | 1.0 Mt/yr | ~40–75 MW | ~205–385 MWp | ~480–900 MWh | E‑calciner + grinding trains |
| OPC (e‑kiln) | 1.0 Mt/yr | ~80–120 MW | ~410–620 MWp | ~960–1,440 MWh | Higher temp; use only where needed |
We bias toward LC³/CSA/geopolymer for carbon sanity and regional clay abundance.
Bill of materials (per product)
Per 1 t solar float glass (typical batch)
| Input | Amount | Notes |
|---|---|---|
| Silica sand | ~720 kg | Low‑iron grades |
| Soda ash (Na₂CO₃) | ~210 kg | Lowers melt temp |
| Limestone & dolomite | ~150–190 kg | Stability & durability |
| Cullet (recycled) | ~200–350 kg | Energy reducer |
Exact recipes vary by plant and product; cullet displaces virgin inputs one‑for‑one.
Per 1 t LC³ binder (illustrative)
| Input | Amount | Notes |
|---|---|---|
| Clinker (reduced) | ~40–55% | Lower‑temp phases preferred |
| Calcined clay | ~30–45% | 700–900 °C |
| Limestone (fine) | ~10–15% | Synergy with clay |
| Gypsum & tweaks | ~3–5% | Set control |
Use local clays and limestone. Electrified calciners make geography our friend.
Footprint & neighbors
Areas (indicative)
- Solar glass, 1 Mt/yr (4 lines): ~60–100 ha (buildings & yards)
- Bricks/blocks, 0.5 Mt/yr: ~15–30 ha (with stockyards)
- Binder, 1 Mt/yr: ~30–60 ha (quarry + plant)
- PV fields (min): see scenarios; landscaped as solar meadows
Air & water
- All furnaces/kilns enclosed; baghouses & scrubbers keep PM low.
- Cooling loops closed; lake buffers seasons (Part 1).
- Noise baffled; light faces down; hawks keep their sky.
Tap‑to‑open Q&A
“Isn’t melting glass energy‑hungry?”
It is — that’s why we do it with electricity. Our solar seed factory (Post 3) prints megawatts; glass turns them into sunlight collectors that print more. Cullet and heat recovery cut the appetite further.
“Do electric kilns make bricks as strong?”
Yes. Strength is chemistry and temperature profile, not whether flames touched it. Electric control is tighter, so quality gets boringly repeatable.
“What about cement’s process CO₂?”
We reduce clinker (LC³), run lower temps with electrons, and use carbonation curing to bind CO₂ into blocks. The binder stops being a weather event and becomes, simply, a recipe.
“Can these plants live near towns?”
That’s the plan. Electric melters, enclosed lines, covered conveyors, and transparent monitoring turn “heavy industry” into a polite neighbor with a great park (the lake).
Up next: Factories That Build Factories — Modular Lines & Rapid Cloning (Part 10). The kit that lets us multiply clean industry like seedlings after rain.