Briquette-form alloying products are used in casthouses and foundries for accurate compositional adjustments of alloy melts or for bulk element addition. The distinctive shape of these products is created as the product's components are compressed between pillow-shaped indentations on two opposing rollers. This shape promotes ease of transport, storage and handling – both in large-scale casthouse furnace additions and in smaller-scale foundry additions.
Carefully Controlled Mixture of Alloying Elements
Briquetted alloying products contain a carefully controlled mixture of alloying element (75%, 80% or 85%) in powder form, aluminium powder and optional sodium-free non-hygroscopic flux . The briquettes are produced using a patented process that assures a high degree of element purity, product consistency and process control. Dissolution relies on the alloying element powder particles forming aluminides. It is recommended that the briquettes be charged after melting is completed and the bath has been skimmed; recommended minimum temperature of 720°C (1,328°F). Normal furnace stirring to ensure a uniform mixture is sufficient to assure complete dissolution of the briquettes.
Rapid Dissolution with Quick-Sol Formulations
Certain briquette grades contain flux – preferred where speed of dissolution is important or when low melt temperatures and stirring difficulty are issues. The flux aids in removal of the oxide film found on any powder particle to expose the metallic element to molten aluminium, promoting rapid dissolution.
Benefits of Alloying Briquettes
• Rapid dissolution at normal casthouse operating temperatures.
• Concentrated form – means reduced inventory, transport and storage costs compared with binary master alloys.
• High element recovery – typically over 95%.
• Minimal temperature loss upon addition.
• Clean and accurate addition.
• Rapid, consistent solubility of self-sinking briquettes means less energy and less cost.
• Color-coded packaging.
Recommended Addition Practice
After calculating the required addition, skim off heavy dross and add the self-sinking briquettes evenly over the melt surface. Hold the bath temperature for 5-10 minutes, then stir well to maximize recovery and homogeneity.