RFM Material Skim Ring For Ingot Casting

The RFM Slag Retaining Ring, also known on production floors as Skim Ring or SKIM DAMS, is a core refractory component designed specifically for aluminum hot‑top semi‑continuous casting lines. It is widely adopted in the production of high‑end aluminum slab ingots used for aerospace, railway transportation, and automotive body sheet applications.

Fabricated with high‑performance RFM composite refractory material, this Skim Ring features excellent thermal shock resistance, superior molten aluminum erosion resistance, and zero aluminum adhesion during continuous high‑temperature operation. The material structure avoids powder falling, peeling, and secondary contamination of molten aluminum, ensuring stable and long‑lasting service performance with reusable characteristics. Many casting plants rely on our SKIM DAMS solution to stabilise melt quality across long production runs.

After degassing and bag filtration, molten aluminum flows into the hot‑top crystallizer area. Liquid level fluctuation and flow turbulence inevitably generate aluminum oxide dross and surface oxidation scales during casting.

Installed floating on the molten aluminum surface at the crystallizer inlet, the RFM Slag Retaining Ring (Skim Ring / SKIM DAMS) physically traps all oxide dross and floating slag within the outer annular zone. Only purified, dross‑free molten aluminum flows inward through the ring center into the crystallizer for solidification and slab forming.

This physical isolation method is the core function of a well‑performing Skim Ring: it effectively prevents slag from being involved by molten aluminum turbulence, drastically reducing slab defects such as inclusions, surface peeling, and internal porosity. It significantly improves finished ingot yield and lowers rejection rates in subsequent rolling processes. Foundries often report fewer downgraded slabs once they upgrade their SKIM DAMS to RFM grade.

• Premium RFM Refractory Material: 

Optimized for high‑temperature aluminum casting environments, featuring strong anti‑erosion performance, stable structural strength, and no reaction with molten aluminum. This material forms the base of our durable Slag Retaining Ring / Skim Ring / SKIM DAMS.

• Reliable Dross Isolation Performance: 

Rectangular ring structure perfectly matches standard aluminum slab crystallizers. Our Skim Ring provides stable floating positioning and consistent slag blocking effects throughout the casting cycle.

• Reusable & Cost‑Effective: 

Resistant to thermal cracking and peeling. After simple surface cleaning, the Slag Retaining Ring can be reused for multiple casting batches, greatly reducing overall consumable costs compared to single‑use SKIM DAMS alternatives.

• Customized Size Support: 

Customizable outer shape, thickness, and inner hole dimensions according to customer crystallizer parameters and slab specifications. We tailor‑make each Skim Ring to fit existing crystallizer assemblies.

• High‑grade aluminum slab hot‑top semi‑continuous casting (using Slag Retaining Ring / Skim Ring / SKIM DAMS) 

• Aerospace grade aluminum ingot production 

• Railway & transportation aluminum sheet manufacturing 

• Automotive body and exterior panel aluminum casting 

• All aluminum casting lines requiring strict molten metal purity control

Q1: What casting process is the RFM Skim Ring used for?

It is professionally applied to aluminum slab hot‑top semi‑continuous casting systems. This Slag Retaining Ring, also named SKIM DAMS, is installed at the inlet of the hot‑top crystallizer to control floating oxide slag.

Q2: What are the advantages of RFM material for a Skim Ring?

RFM is a high‑performance composite refractory material developed specifically for aluminum casting working conditions. When manufactured into a Slag Retaining Ring or SKIM DAMS, it provides excellent thermal stability, anti‑stick aluminum performance, and strong resistance against molten metal corrosion without shedding powder or contaminating aluminum liquid.

Q3: Can the Slag Retaining Ring / Skim Ring be reused?

Yes. With normal operation and regular surface dross cleaning, the RFM Skim Ring maintains complete structural integrity and can be reused for multiple production cycles, helping factories reduce casting consumable costs versus disposable SKIM DAMS.

Q4: Do you support customized sizes for Skim Ring?

We provide full custom service according to customer crystallizer inner size, slab width and thickness requirements. Each custom‑built Slag Retaining Ring (SKIM DAMS) achieves perfect fitting and optimal slag blocking performance.