Mica is a class of silicate minerals that are physically and chemically similar in a layered structure. They possess excellent properties for thermal and electrical resistance, therefore being ideal for high temperature insulation solutions. Mica is mined in over 35 countries, with India and Madagascar being the largest sources, followed by China and Brazil. Mica plays a crucial role in various industries, from cosmetics to electronics. All of our products contain mica, the majority of which is mined in very poor countries by artisanal miners living in very poor conditions. Due to these circumstances, ensuring sustainably sourced mica becomes much more significant.
To answer why silicate mineral is used as a thermal insulator, we should first take a step back and dive into exactly what silicate minerals are. Silicate minerals are made up of silicate groups, and play major roles in the formation of rocks within the Earth. These minerals are actually the largest class of minerals, making up approximately 90% of the Earth’s crust. Silica, SiO2, is found naturally as the mineral quartz and its polymorphs which allow it to crystallise into different crystalline forms. These different forms represent a wide range of combinations, as various silicate minerals occur as the result of different processes taking place over billions of years.
The anions in silicate minerals predominantly consist of silicon and oxygen atoms, and these anions are used to determine the major silicate mineral groups. These groups include Nesosilicates, Sorosilicates, Cyclosilicates, Tectosilicates and our focus for this article, Phyllosilicates. Formed by sheets of silicate tetrahedra, phyllosilicates are highly abundant and include the likes of clay minerals, serpentine, chlorite and mica.
Mica is the key component within many of our high temperature insulation products and solutions at Elmelin. It has a variety of beneficial physical and chemical properties that make it ideal for insulation, and over the years we have continued to develop highly effective mica-based insulation solutions for a range of industrial applications. So, when considering why silicate minerals are used as a thermal insulator, our experience and expertise with mica will be used as a prime example.
Mica is at the core of our range of industrial insulation solutions. Our goal is to improve the safety, performance and lifespan for a range of industrial applications. Mica is a widely-used mineral that is sourced from mining in many countries but predominantly India and Madagascar, using artisanal mining techniques Here we’ll discuss mica basics and essentials, as well as which of its properties make it so ideal for industrial insulation.
Insulation solutions for consumer appliances are required to ensure their safety and longevity. Many consumer appliances are used regularly and they need to be functioning over a long period of time. Millions of households in the UK will have appliances such as hair dryers and toasters, with many also having convection or fan-assisted heaters. The sheer volume of these appliances mean that there is a demand for insulation providers to offer solutions and high quality insulating materials for these products.
Elmelin specialise in mica-based insulation, with strong expertise in mica itself, and decades of experience with industrial insulation. With adaptability and innovation at the forefront of our values, we have developed outstanding mica-based insulation products for a variety of industries and purposes. The manufacturing and selling of consumer goods and appliances is a competitive market, and these products require excellent insulation solutions to improve their end-user safety and performance. Products such as hair dryers and toasters are exposed to high voltages and temperatures in their day-to-day operation, so it’s key that the insulation used is efficient but also long-lasting.
Mica is incredibly versatile, with the potential to be applied to many different products and solutions. From large-scale furnaces, to handheld consumer appliances, mica can be moulded and processed into various shapes and sizes. It is a naturally occurring silica-based mineral and due its unique chemical composition and physical properties, it is often used as an electrical and thermal insulator.
Mica’s dielectric and thermal resistance properties make it an excellent choice for industrial insulation, yet it is the smooth surface layers that form the mineral which make it so versatile. The smooth surfaces are formed when mica splits along crystalline planes, which results in perfect basal cleavage. Because of this, the mica is flexible and can be shaped into a variety of products including sheets, rolls and tubes.
Mica is a group of minerals that form in multiple tightly packed layers. This two-dimensional sheet structure is the reason for mica being known as silicate sheets. They are found in all three major rock varieties and have certain chemical properties which lends mica to being incredibly useful for industrial insulation.
Due to the layering of the minerals, mica is suited to being produced as mica papers which can be converted into sheets and flexible roll materials. Two of the key properties of mica rolls and mica sheets is the resistance to high temperatures and its inability to conduct electricity. Mica sheets and rolls use these properties, as well as its chemical resistance and durability, in order to work as a highly efficient insulating and reinforcing agent.
Mica can also be rigid or flexible, with flexible being used mainly for furnace insulation and automotive gasket application due to its fantastic electrical resistance under high temperatures. Rigid mica sheets are used for sheathing passive fire protection and dielectric barriers within multiple applications.
There are two types of mica mineral used by Elmelin, Muscovite and Phlogopite. Muscovite mica has a higher dielectric strength, therefore having greater insulating properties, while also being a very poor conductor of electrical currents. Because of this, muscovite is widely recognised as the best mica type for electrical applications and devices. As well as this, muscovite mica can be highly durable and both flexible or rigid depending on resin composition.
Phlogopite mica is similar to muscovite mica; it is more heat resistant than muscovite, and as well a poor electrical conductor and can be manufactured flexible or rigid depending on use. They are the only two mica minerals that are used commercially,
Here we discuss the major advantages of mica’s thermal, electrical and physical properties for industrial insulation.
As a naturally occurring mineral, Mica is a durable material that retains its form when exposed to high temperatures, electrical charges, and light and water. Due to its versatility and thermal resistance, it is used across various industries and in a range of products. In fact, almost every individual will use several products that contain Mica components before leaving the house in the morning.
We have spoken extensively about the properties of Mica, of which there are many! See our previous blog on ‘The Benefits of Mica’. However, due to the growing demand for Mica across developing countries and increased demands from the electrical and automotive industry, we are concerned that global regulations on mining such material will not mirror the pace of change.
Passive fire protection, sometimes referred to as PFP, is a method of fire protection that seeks to slow the spread of a fire and smoke by containing it within the compartment of origin for a limited period of time. PFP is an integral part of building construction, heavily regulated by building codes. Passive fire protection measures usually involve the structural or mechanical inclusion of a fire resistant material around the compartment in question. It’s the opposite of active fire protection, which usually uses some sort of electrical component to detect and then suppress the fire. …
Mica insulation has impressive thermal and electrical properties making it a suitable material to solve many engineering challenges. Elmelin have developed processing capabilities to cut, stamp and shape mica to address these challenges. We frequently work with clients to design and cut mica to fit their bespoke applications. Due to its versatility, mica is highly adaptable, so with that in mind, let’s take a look at some of the common applications of cut and shaped mica.