# Lead processing - Stage 4 (technology)

internal name `lead-mk04` · tier 7 (Production science pack, [tier 7](https://factorio.kalzumeus.com/tier/7.md))
HTML page: https://factorio.kalzumeus.com/tech/lead-mk04/

## Cost

1200 units of (1 × [Production science pack](https://factorio.kalzumeus.com/item/production-science-pack.md), 2 × [pY science pack 3](https://factorio.kalzumeus.com/item/py-science-pack-3.md), 3 × [Chemical science pack](https://factorio.kalzumeus.com/item/chemical-science-pack.md), 6 × [pY science pack 2](https://factorio.kalzumeus.com/item/py-science-pack-2.md), 10 × [Logistic science pack](https://factorio.kalzumeus.com/item/logistic-science-pack.md), 20 × [pY science pack 1](https://factorio.kalzumeus.com/item/py-science-pack-1.md), 30 × [Automation science pack](https://factorio.kalzumeus.com/item/automation-science-pack.md), 6 × [Military science pack](https://factorio.kalzumeus.com/item/military-science-pack.md)), 300 s each.

## Requires (2)

- [Lead processing - Stage 3](https://factorio.kalzumeus.com/tech/lead-mk03.md)
- [Production science pack](https://factorio.kalzumeus.com/tech/production-science-pack.md)

## Leads to (1)

- [Lead processing - Stage 5](https://factorio.kalzumeus.com/tech/lead-mk05.md)

## Unlocks (2 recipes)

### Molten lead (`molten-lead-04`)

- 3 s · tier 7
- Ingredients: 1 × [Reduced 99.9% lead](https://factorio.kalzumeus.com/item/reduced-lead.md), 3 × [Borax](https://factorio.kalzumeus.com/item/borax.md), 3 × [Graphite](https://factorio.kalzumeus.com/item/graphite.md)
- Results: 1000 × [Molten lead](https://factorio.kalzumeus.com/fluid/molten-lead.md)
- Made in: Electric arc furnace MK 01, Electric arc furnace MK 02, Electric arc furnace MK 03, Electric arc furnace MK 04
- Unlocked by: [Lead processing - Stage 4](https://factorio.kalzumeus.com/tech/lead-mk04.md)

### Reduced 99.9% lead (`reduction-lead`)

- 4 s · tier 7
- Ingredients: 1 × [High grade lead](https://factorio.kalzumeus.com/item/high-grade-lead.md), 2 × [Sodium sulfate](https://factorio.kalzumeus.com/item/sodium-sulfate.md), 50 × [Diesel](https://factorio.kalzumeus.com/fluid/diesel.md), 100 × [Pressurized air](https://factorio.kalzumeus.com/fluid/pressured-air.md)
- Results: 1 × [Reduced 99.9% lead](https://factorio.kalzumeus.com/item/reduced-lead.md)
- Made in: Direct reduction plant
- Unlocked by: [Lead processing - Stage 4](https://factorio.kalzumeus.com/tech/lead-mk04.md)