Dross Press vs Aluminum Dross Stirring Separator (Stir Ash Machine)

Both dross press and aluminum dross stirring separator (commonly called stir ash machine) are equipment for processing hot aluminum dross and recovering metallic aluminum. However, they differ greatly in working principle, structure, aluminum recovery rate and application scenarios. The dross press adopts high-pressure extrusion, while the stir ash machine uses mechanical stirring + gravity specific gravity separation.

1. Working Principle

Dross Press

Working principle: High temperature and high pressure extrusion.Load 700–800℃ hot aluminum dross into a special steel crucible; the hydraulic head applies high pressure (50–100 tons) to squeeze out liquid aluminum, meanwhile isolating air and preventing oxidation.Core feature: No heating or stirring, only extrusion. Fast processing (10–15 minutes per batch) with minimal oxidation loss.

Aluminum Dross Stirring Separator (Stir Ash Machine)

Working principle: Mechanical stirring + specific gravity difference separation.Pour hot aluminum dross into the tank; rotating stirring paddles churn and rub the dross. By specific gravity difference, heavy molten aluminum sinks and light ash residue floats up. Molten aluminum flows out from the bottom outlet, and waste ash is discharged from the top.Core feature: Separation relies on stirring and gravity; self-heating from aluminum oxidation maintains temperature with no extra fuel needed, but stirring accelerates aluminum oxidation.

2. Detailed Differences

Operation Mode

Dross Press: Static high-pressure extrusion, no stirring or turnover.

Stir Ash Machine: Dynamic forced stirring with continuous material turnover and friction.

Aluminum Recovery Rate

Dross Press: 92%–98%, extremely low oxidation loss.

Stir Ash Machine: 85%–92%, oxidation burning loss 3%–8% caused by stirring.

Processing Efficiency

Dross Press: 10–15 minutes per batch (1 ton per crucible), suitable for continuous mass production.

Stir Ash Machine: 30–60 minutes per batch (300–800kg per tank), lower efficiency.

Oxidation & Burning Loss

Dross Press: Barely no oxidation; air-isolated extrusion, oxidation loss less than 1% per minute.

Stir Ash Machine: Obvious oxidation; material exposed to air during stirring with high burning loss.

Equipment Cost

Dross Press: High cost (hydraulic system + custom steel crucible).

Stir Ash Machine: Low cost (simple mechanical stirring structure).

Maintenance & Energy Consumption

Dross Press: Simple maintenance, no wearing stirring paddles; medium to high energy consumption (hydraulic power unit).

Stir Ash Machine: Frequent maintenance (stirring paddles wear easily); low energy consumption (only stirring motor).

Application Scenarios

Dross Press: Large aluminum smelters & aluminum recycling plants, daily output over 20 tons, prioritizing high recovery rate and low burning loss.

Stir Ash Machine: Medium & small foundries, die-casting factories, daily output under 10 tons, limited budget and factory space.

Summary

Dross Press: High-end & high-efficiency, extrusion-type aluminum preservation, higher investment but cost-effective in long term.

Stir Ash Machine: Economical & practical, stirring separation type, low initial cost but higher aluminum burning loss.