Mica insulating material to improve industrial furnace safety

Mica insulating material to improve industrial furnace safety

The steel and foundry industry has been a major contributor to global manufacturing, producing a hugely vast range of materials, appliances and products. It’s an enormous industry, and crucial for meeting the intense production demands that exist in the current climate. Industrial furnaces, whether electric arc or coreless induction, reach extremely high temperatures in order to melt down the metals. Steel casting uses moulds to shape and form molten metal into pipes and tube fittings, automotive parts and machinery components.

In 2020, the revenue generated in the iron and steel casting industry was in excess of USD 145 billion. Moreover, even with the detrimental effects of COVID-19, there is still an estimated compound annual growth rate of over 5.4% from 2021 to 2027. In Europe, the CAEF, or The European Foundry Association, is responsible for the overall production of metal castings. Founded in 1953, the CAEF is now an alliance of 23 national foundry associations from 22 European countries. European production accounted for 16.8 million tonnes of the 112.7 million tonnes of castings produced globally. 

When discussing furnace safety, this just doesn’t just refer to the health and safety of staff working with them, but also an induction furnace’s operational capabilities as well. These large, expensive pieces of equipment are required on a daily basis working at maximum efficiency and capacity. With the steel and foundry industry being so demanding, it’s crucial to ensure that they operate consistently and avoid breakdowns. Here we’ll discuss the benefits of mica insulation for furnace safety.


Keeping furnaces operational

Industrial furnaces are at the heart of any foundry, with the purpose of melting down metals into liquified states, which can then be applied to moulds and casts to form the required components or products. The high temperatures used for the melting require careful measures to improve safety. Induction furnaces require high temperature insulation to ensure damage doesn’t occur, which can then lead to breakdowns or inefficient performance. 

The need for better insulation materials has become more apparent as manufacturing aims to become leaner, more efficient and less wasteful. Therefore innovations in insulation have been required to improve the furnace performance and safety. Elmelin offer mica-based insulation solutions, using its superior insulating properties to help improve furnace efficiency and lifespan. These properties are the reason for mica insulation being used for furnace safety.


Why is mica used for insulation?

Mica has multiple properties that make it an excellent choice for industrial insulation solutions. From a production perspective, mica has mechanical properties that make it suitable to manufacture into different shapes and sizes. Mica splits along crystalline planes to form smooth surfaces, therefore having a perfect basal cleavage. This makes it highly flexible and easy to adapt into very thin sheets, rolls and tubes. 

Furthermore, muscovite and phlogopite mica have sectile and elastic tenacity. The tenacity of a mineral is essentially how it responds to stress. Sectile tenacity is when the mineral can be cut with a sharp object, whereas elastic tenacity is when the mineral can be bent under stress, yet returns to its original shape once the stress is removed. These qualities again makes mica ideal for adapting to different shapes and sizes as required. 

While these make mica easier to work with, its dielectric and thermal resistance properties are the reason for mica being so beneficial as an insulator. Mica can withstand up to >20 kV/mm, and can store charge in an electrostatic field. These dielectric capabilities help form barriers which act as a safety feature protecting workers from an induction furnace’s electrically charged coils. 

Its thermal resistance properties are more than ideal for furnace insulation. The extreme temperatures reached in coreless induction furnaces require mica-based laminate composites which can withstand temperatures up to 1600°C. It helps protect the induction coils while processing metal, and can also protect against damage from vapour fumes, which can build up damaging metals.

Mica is also used in slip plane lining, in order to increase throughput in an induction furnace, in turn extending the life of the lining. Furthermore, it can be used as part of a seal in a vacuum furnace, which improves its efficiency and safety by withstanding the high temperatures and stresses.


Mica insulation products for furnace safety

Elmelin produce a range of mica-based products that help improve furnace safety. Elmesh is a mica mesh flexible laminate, with a dielectric strength of >5.0 kV/layer and heat resistance up to 1200°C. It has multiple uses, for instance it helps protect coil grout by providing a dielectric barrier. It can also be connected to an earth leakage system, in order to provide an early warning if a breach in the furnace lining were to occur. These breaches can lead to metal penetrating the coil grout and cause furnace damage as well as threatening the health and safety of the employees. 

Vapourshield, a flexible mica laminate, helps to prevent hazardous fumes reaching an induction core. It’s made from a stainless steel layer in between 2 layers of mica, and has a dielectric strength of >5.5 kV/layer. It also has a very low heat conductivity at

500°C mean temperature, approximately 0.63 W/m°C. The hazardous fumes it prevents can form residues on a furnace’s coils, which leads to corrosion and misreadings on a furnace’s electrical components. 



The steel and foundry is of massive importance to global manufacturing. It provides not only millions of tonnes of highly in-demand materials and components, but also thousands of jobs for people, and a significant amount of revenue for the world’s economy. 

The demand is continuing to increase, and therefore it is of utmost importance that the industrial furnaces used are kept safe. They need to be efficient, maxing out their capabilities and having the longest lifespan possible. If a large-scale induction furnace is to become damaged and breakdown, production lines are impacted greatly. 

Elmelin’s insulation solutions help to mitigate problems that can occur with these furnaces, and our mica-based products increase their longevity and safety. Elmelin provide vital protection for the furnace coil grout and support safe furnace working practices with their furnace safety systems, Elmesh and Vapourshield.

Get in touch here to find out more about the solutions Elmelin offer.