Metal recycling: how scrap becomes new metal
Page brief. Target keyword:
metal recycling. Audience: sellers who want end-to-end context on what happens to their scrap, plus environmentally-curious readers checking the carbon and energy claims. Funnel stage: awareness. The page should answer: what's the actual chain from a piece of scrap to a finished mill product, and why is metal one of the few streams that genuinely works?
This category covers the core recycling streams — steel, aluminum, copper, brass — from the moment a piece leaves its original use to the moment it ships out of a mill as new product. Steel alone is the most-recycled material on earth by tonnage, and aluminum recycling saves around 95% of the energy of primary production. The pages here trace why those numbers work, who handles each step, and where the economics break.
What this category covers
The recycling chain has five steps. Each one has its own operators, equipment, and economics. Sub-topics:
- Collection — yards, drop-off, curbside, contractor pickups
- Sorting — visual + magnet + density + XRF, depending on the operator
- Processing — shred, shear, baler, granulator (sized to the mill's furnace charge)
- Melting and refining — EAF for steel, secondary smelter for non-ferrous
- Casting and rolling — ingot, billet, coil, ready for fabricators
The recycling chain by metal
Different metals route through different downstream paths. A simplified map:
| Metal | Primary furnace | Typical recovered yield | Energy savings vs. primary |
|---|---|---|---|
| Steel (carbon) | Electric arc furnace | 95%+ | 60–75% |
| Aluminum | Reverberatory / induction | 90–95% | around 95% |
| Copper | Anode furnace + electrolytic refine | 95%+ | 85–90% |
| Brass | Direct remelt | 95%+ | 80–90% |
| Stainless | EAF (alloy mill) | 90%+ | 50–70% |
Real per-tonnage flow numbers and provincial mill maps belong on the leaf pages — see Metal Recycling: How It Actually Works for the prototype.
Why mass-recovery rate matters
A material is genuinely recyclable when most of its mass survives the recycling process and ends up in the next product. Metal recycling clears that bar; most plastics don't. Sub-bullets the leaves will expand:
- Mass loss in steel recycling is mostly oxidation in the furnace and slag-bound contaminants — kept under 5% in modern EAFs
- Aluminum recycling loses some metal to dross (oxidized aluminum on the melt surface) but stays above 90%
- Copper recovers nearly perfectly because it's electrochemically refined back to above 99.9% pure
- Painted, oily, or coated material costs the mill in pre-treatment — that cost flows back to the seller as a grade downgrade
What gets rejected and why
- Sealed refrigerant systems — must be evacuated; mill receiving it intact is a regulatory issue
- Lithium batteries — fire risk in shredders, fully separate stream
- Mercury-bearing switches and thermostats — toxic, regulated handoff
- Heavily-painted scrap — older lead paint flagged in many states
- PCB-contaminated transformers — pre-1979 oil-filled units have to be tested
A clean-load checklist will live on the leaf pages — start with Metal to Be Recycled: A Sorting Guide.
Topic ideas / outline
Future leaves should cover:
- The full five-step chain with photos from each step
- EAF vs. BOF — why the recycling story is mostly an EAF story
- The aluminum recycling carbon math (the strongest environmental case in the entire industry)
- Copper electrolytic refining — how scrap becomes 99.99% copper again
- Why brass is "directly remeltable" (no refining step required)
- Stainless recycling and the nickel cycle that drives the spread
Frequently asked questions
Why does metal recycling work when plastic doesn't?
Mass-recovery rate. Metal recycling routinely returns 90%+ of input mass as usable output; mechanical plastic recycling often returns far less, and the polymer chains degrade with each cycle. Metal doesn't degrade — every atom of recycled steel is identical to virgin steel.
How much energy does aluminum recycling actually save?
Roughly 95% vs. primary aluminum production from bauxite. Secondary aluminum is one of the few industrial streams where the energy and carbon math is uncontroversially good. Live aluminum pricing reflects this — energy spikes hit primary harder than secondary, see Aluminum Price.
Where does my scrap physically go?
Yard, then regional processor, then mill. Existing leaves like Recycle Scrap Steel and Scrap Metal Recycling trace the chain in detail.
Related guides
- Metal Recycling: How It Actually Works — the canonical end-to-end leaf
- How to Recycle Scrap Steel — the highest-tonnage stream
- Scrap Metal Recycling Explained — environmental and economic case
- Metal to Be Recycled: A Sorting Guide — what's accepted, what's rejected
- Auto Recycling — end-of-life vehicles run a parallel chain
- E-Waste Recycling — circuit boards and harnesses follow yet another
- Construction & Demolition — the largest source of recyclable metal by tonnage
- Scrap Guide / Basics — the seller's-side foundation
- Copper Price — live pricing context for the copper end of the chain
- Aluminum Price — live pricing for the aluminum end