Managing High Temperatures in Metal Processing

High temperatures are an essential part of the processing of raw materials into useful metals. The most utilised metals including steel, stainless steel, cast iron, alloy steel, aluminium, copper and copper alloys used in electrical wires, are often developed through an expensive process. The precise management of temperature is essential to ensure an already costly process does not increase in cost but also to ensure the safety of workers.

What is metal processing?

The initial process in the production of a useable metal is the extraction of the ore from the earth in the mining process. Typically, the ore extracted is made up of multiple mineral and other elements as well as the rock that these minerals are suspended in . The mined materials go through a number of processes to extract the useful metal from the ore. The first stage is normally a chemical process that separates the different minerals and produces a concentrate that can be sent to the next refining process. In many operations the next stage is a smelting process. This process is highly intensive and requires high temperatures and chemical reducing agents. The equipment used during the extraction process must be able to withstand extreme temperatures, in many cases up to 1600°C or higher.

The pure metal, now extracted from the ore, is often too soft or brittle for practical use, so needs to be combined with other elements to create an alloy. This allows for the metal to become stronger or more useful in applications.

Metal processing inAustraliais predominantly focused on the steel industry.  Pyrosales has a long relationship with many metal manufacturers inAustralia, including Bluescope Steel and One Steel.

Blast furnaces are one of the most common type of furnace used in metal processing and can handle temperatures of up to 2300°C. Electric arc furnaces can generally handle temperatures of up to 1800°C.

It is essential that the temperature in the furnace is monitored and managed. Firstly, to ensure the desired reaction takes place, and secondly, that safety is not compromised. Any fault or error can result in explosion or fire which can be costly but also have potentially devastating results.

Equipment that can handle high temperatures is the only option in metal processing. For temperature above 1250°C, the only choice is to use platinum-based thermocouples. Platinum-based thermocouples are extremely effective, but they are costly, so it is imperative they are used properly and adequately protected from the environment they are utilised in. To protect the sensor it is housed in a protection sheath. While there may not be an ideal protection sheath for every process environment, Pyrosales will select, after analysis of the process conditions, the most suitable thermocouple/sheath combination to best suit the needs of the customer. By doing this, the customer can be assured that the most cost‐effective solution to their temperature sensing problem has been applied.