Graphite COVA GmbH: Where precision meets performance in carbon and graphite solutions

Located in Nuremberg, Germany, with a rich heritage spanning over 150 years, Graphite COVA stands out as a leading global carbon and graphite manufacturer. Our commitment to quality is evident through our ISO 9001:2015 certification.

As a premier manufacturer of carbon and graphite materials, we cater to a diverse clientele worldwide. We provide high-quality feedstock and parent materials to numerous graphite machine shops, empowering them to craft precision components according to their specifications.

In addition to supplying raw materials, Graphite COVA boasts its state-of-the-art graphite machine shop. Here, we produce meticulously crafted components tailored directly to end customers' requirements, ensuring adherence to their precise designs. Our specialization in products for the aluminium industry is a cornerstone of our offerings, further supported by an in-house antioxidation treatment facility. This facility ensures the longevity of our products, maintaining their performance over an extended lifespan.

Graphite COVA boasts an advanced graphite machine shop that produces machined components tailored directly to clients' specifications. Our primary focus lies in supplying products for the aluminium industry, complemented by an in-house antioxidation treatment facility to enhance product longevity.

Aluminium Industry

• Graphite Fluxing Tubes with porous plugs
• Graphite Impeller Systems for Aluminium Degassing (Rotors, Shaft & Stator )
• Casting Rings for Hot Top Casting or for Gas Slip System
• Graphite Plates and Rolls for Aluminium Extrusion Presses
• Anodizing Electrode etc

Graphite for aluminium production

The outstanding thermal stability of graphite allows for its full utilization in the production processes of primary aluminium and aluminium semi-products. To ensure top-quality results, CNC-controlled technology is employed in machining processes, alongside the utilisation of anti-oxidative impregnation for the graphite material.

Primary aluminium making

Graphite blenders, pumps, degassing rotor shaft, casting rings

Aluminium Casting

Gas injection systems-for the purification of melted aluminium for various types of appliances and systems

Aluminium semi products (extrusion)

Graphite dies, moulds, seal rings, run-out table plates, anodizing electrode

Graphite Impeller System: For treating molten aluminium

The presence of dissolved hydrogen in the melt can pose significant challenges in the casting process of aluminium and its alloys. This can lead to the formation of hydrogen gas porosity and subsequent defects in the castings. These defects compromise the castings' strength and increase the risk of blistering during subsequent rolling and annealing processes.

To address this issue, it is customary to treat the molten aluminium with dispersed gases such as chlorine, nitrogen, argon, or their mixtures to remove hydrogen and solid impurities. The conventional method for degassing and purification involves using degassing units equipped with a shaft and rotary head submerged into the melt. The rotary head plays a crucial role in controlling the introduction and dispersion of the gas, generating fine bubbles that facilitate thorough contact of the gas throughout the melt.

One such rotary device, pioneered by Graphite COVA GmbH, comprises a hollow rotary shaft and a rotating pump head attached to it. The pump head features four or more channels extending from the bottom centre to the rotor's outer shell, facilitating the melt's pumping and circulation. Additionally, it incorporates four or more jet holes for gas injection, connected to the hollow shaft and angled towards the surface of the rotor head.

While the rotor head typically connects to the shaft via a cylindrical nipple, alternative connection designs are available upon request to suit specific requirements.