Silicon Metal Refining

A variable mixture of oxygen and/or instrument air is supplied from a refining panel through flexible piping to the metal ladle during the tapping of the metal into the ladle, the refining of the metal in the ladle, the casting of the metal into moulds and the de-slagging of the metal ladle once the casting is completed. The panel has two gas supply connections i.e. one compressed air and one oxygen supply.

The compressed air is passed through a desiccant type drier before it is connected to the two automated refining stations and two manual instrument air bypass valve stations on the panel.

Automated flow control valves in each line of a refining station regulate the flow rate for each gas to a pre-selected value based on the specific process. Flow meters located after the flow control valves are used to provide the feedback for the required accuracy. The outlets from the two flow control valves and flow meters for each refining station combine into a single refining gas outlet connection. The panel has thus two independent refining gas outlet connections. The two manual by pass valve stations are not combined.

The selection for the specific process i.e. tapping, refining, casting and de-slagging to determine the specific gas mixture required, is manually performed by the furnace tapping operator from the local refining control panel. The furnace tapping operator also enters the ladle number on the local control panel. Once a specific process is selected, the instrument air and oxygen is automatically adjusted and controlled.