The Innovative Application of Diatomite Fillers in the Insulation and Heat Insulation Materials Industry

Analysis of the Characteristics and Industry Compatibility of Diatomite Fillers

As a natural inorganic non-metallic mineral material, diatomite fillers demonstrate outstanding application value in the field of insulation and heat insulation materials. This porous material formed by the deposition of ancient diatom fossils mainly consists of amorphous silica and has unique physical and chemical properties, including high porosity (typically 80-90%), low thermal conductivity (0.03-0.06W/(m·K)), large specific surface area (20-60m²/g), and excellent high-temperature resistance (melting point >1300℃). These characteristics of diatomite fillers make them an ideal choice for high-performance insulation and heat insulation materials.

Microscopically, diatomite fillers exhibit a regular nanoscale pore structure, which gives the material excellent insulation properties. Compared with traditional insulation materials, diatomite fillers-based insulation materials not only have a lower thermal conductivity but also possess additional values such as non-combustibility, non-toxicity, and mold resistance. With the continuous improvement of building energy-saving standards and the growth of demand for green building materials, the application of diatomite fillers in the insulation and heat insulation industry is expanding rapidly.

The Application of Diatomite Fillers in Building Insulation Materials

In the field of building insulation, diatomite fillers are mainly used in exterior wall insulation systems, roof insulation layers, and indoor temperature regulation materials. As functional fillers, diatomite fillers can significantly improve the performance deficiencies of traditional insulation materials. For example, adding 15-25% of diatomite fillers to expanded perlite or glass microsphere insulation mortar can reduce the thermal conductivity of the material by 10-15% and increase the compressive strength by more than 20%.

The application of diatomite fillers in lightweight insulation mortar is particularly prominent. By combining diatomite fillers with cement, polymer powder, etc., high-performance insulation mortars with a dry density of 300-500kg/m³ and a thermal conductivity of 0.06-0.08W/(m·K) can be produced. These mortars not only have excellent insulation properties but also can effectively regulate indoor humidity due to the moisture-regulating function of diatomite fillers, creating a more comfortable living environment.

In the development of new insulation boards, diatomite fillers also play a key role. Using diatomite fillers as the main raw material, combined with inorganic binders and reinforcing fibers, A-grade fire-resistant diatomite insulation boards can be produced. Test data shows that a 30mm thick diatomite insulation board has a thermal resistance value equivalent to a 40mm thick EPS board, and is completely non-combustible, with a smoke toxicity level reaching AQ1 grade, especially suitable for public buildings with high fire resistance requirements.

It is worth noting that the application of diatomite fillers in building insulation also reflects their excellent durability. Compared with traditional organic insulation materials, insulation systems containing diatomite fillers are less prone to aging and can have a service life of up to 50 years. Meanwhile, the hydrophobic modification technology of diatomite fillers has been mature, and through surface treatment, the water absorption rate can be reduced to below 5%, effectively solving the industry problem of porous materials being prone to water absorption.

Solutions of Diatomite Fillers in Industrial High-Temperature Insulation

In the industrial high-temperature insulation field, diatomite fillers demonstrate irreplaceable advantages. For the insulation requirements of high-temperature equipment in industries such as metallurgy, chemical engineering, and power, high-temperature insulation materials developed with diatomite fillers as the base can operate stably at 800-1000℃, which is a performance level that most organic insulation materials cannot achieve.

Silicon dioxide-based fillers have diverse application forms in high-temperature insulation products, including silicon dioxide insulation bricks, silicon dioxide casting materials, and silicon dioxide fiber products, etc. Among them, the lightweight silicon dioxide insulation bricks use silicon dioxide fillers as the main raw material, add an appropriate amount of combustible materials, and undergo high-temperature sintering to form a porous structure. The volume density can reach 0.5-0.7g/cm³, and the thermal conductivity at room temperature is only 0.12-0.15W/(m·K). These products are widely used in the insulation linings of industrial kilns and can significantly reduce the outer wall temperature of the kiln and reduce heat loss.

In higher temperature application scenarios, silicon dioxide fillers are often used in combination with other high-temperature-resistant materials. For example, modular insulation products prepared by combining silicon dioxide fillers with ceramic fibers not only maintain the high-temperature resistance of ceramic fibers but also improve the material's resistance to air erosion and construction convenience due to the addition of silicon dioxide fillers. Practical applications show that the thermal conductivity of this composite material is 15-20% lower than that of pure ceramic fibers, and the energy-saving effect is more significant.

Particularly noteworthy is the application of silicon dioxide fillers in nano-pore super-insulation materials. By combining silicon dioxide fillers with nano-materials such as aerogel, super-insulation materials with a thermal conductivity lower than 0.020W/(m·K) can be produced. These materials have important applications in high-end fields such as aerospace and cryogenic equipment, and the addition of silicon dioxide fillers significantly reduces the material cost and improves the industrialization feasibility.

Technological innovation and performance optimization of silicon dioxide fillers

To fully utilize the potential of silicon dioxide fillers in the field of insulation and heat preservation, the industry has developed several targeted material modification technologies. Surface modification of silicon dioxide fillers is one of the most commonly used technical means. By treating with silane coupling agents, the compatibility between silicon dioxide fillers and organic matrices can be improved, and the performance of the composite materials can be enhanced. Tests show that the dispersion of treated silicon dioxide fillers with KH-550 silane coupling agents in polyurethane foam has significantly improved, and the thermal conductivity of the prepared composite foam plastic is reduced by approximately 12%.

The control of pore structure of silicon dioxide fillers is another important research direction. Through acid washing, high-temperature calcination and other process treatments, the pore size distribution of silicon dioxide fillers can be optimized, and their insulation performance can be improved. It is found that the proportion of 2-50nm mesopores in silicon dioxide fillers treated with appropriate acid increases, and this pore size distribution is most conducive to suppressing convective heat transfer, further reducing the thermal conductivity of the material.

In the composite process, the composite technology of silicon dioxide fillers and aerogels has achieved significant progress. Using silicon dioxide fillers as the support framework of aerogels can not only maintain the ultra-low thermal conductivity of aerogels but also solve the problems of low strength and easy pulverization of pure aerogels. Experimental data show that the compressive strength of the silicon dioxide fillers/silica aerogel composite material can reach 5-8 times that of pure aerogels, while the thermal conductivity remains at an excellent level of approximately 0.018W/(m·K).

From the perspective of microscopic mechanism, the insulation property of silicon dioxide fillers is attributed to their multiple thermal resistance mechanisms: the large number of micrometer and nanometer pores in silicon dioxide fillers can effectively limit the movement of air molecules and reduce convective heat transfer; the complex paths formed between silicon dioxide particles extend the heat conduction path; the phonon scattering at the interface between silicon dioxide fillers and the matrix material also increases the thermal resistance. These mechanisms work together, making the base material of silicon dioxide fillers exhibit excellent insulation performance.

Application cases and performance comparison

In practical engineering applications, insulation and heat preservation materials containing silicon dioxide fillers have demonstrated significant advantages. Taking the insulation and heat preservation project of the exterior wall of a commercial complex as an example, the system using modified insulation mortar with silicon dioxide fillers achieved the same insulation effect (K value = 0.35W/(m²·K)) as the traditional XPS board system, and had the following advantages: the fire resistance grade was raised from B1 level to A level; The system's ventilation efficiency has been improved by three times, effectively avoiding condensation problems; the engineering cost has been reduced by approximately 15%.

In the industrial field, after a 500℃ thermal pipeline of a certain chemical plant was equipped with siliceous earth filler-based composite insulation material, compared with the original mineral wool insulation, the insulation layer thickness was reduced by 30%, and the surface heat loss was decreased by 25%, resulting in an annual savings of approximately 180,000 yuan in steam costs. What is more notable is that the service life of the siliceous earth filler insulation material is expected to reach over 15 years, which is 2-3 times that of traditional materials, and the cost advantage throughout the entire life cycle is obvious.

From the comparison of material performance parameters, the siliceous earth filler insulation material outperforms traditional materials in multiple indicators. Taking the typical siliceous earth filler lightweight insulation product as an example: the thermal conductivity is 0.045-0.065W/(m·K), superior to perlite products (0.07-0.09W/(m·K)); the usage temperature can reach 900℃, significantly higher than polystyrene materials (<75℃); the volume density is 0.2-0.5g/cm³, lower than traditional silicagypsum board (0.7-1.0g/cm³); the water absorption rate is less than 8%, superior to most inorganic porous materials.

In special application scenarios, the advantages of siliceous earth filler are more prominent. For example, in humid environments, the specially treated siliceous earth filler insulation material can maintain stable insulation performance, while most organic materials will experience a sharp decline in performance due to water absorption; in places with fire protection requirements, the non-flammable characteristic of the siliceous earth filler products provides an essential safety guarantee; in places requiring electromagnetic shielding, the appropriately modified siliceous earth filler composite materials can also have both insulation and electromagnetic protection functions.

Market prospects and development trends

With the deepening of global energy conservation and emission reduction policies and the development of building industrialization, the growth potential of siliceous earth filler in the insulation and heat preservation material market is huge. According to industry analysis predictions, the global building insulation material market will grow at an average annual rate of 6.8% in the next five years, among which the growth rate of green and environmentally friendly insulation materials such as siliceous earth filler products will reach 10-12%, significantly higher than traditional materials.

From the perspective of technological development trends, the application of siliceous earth filler will develop in the following directions: first, functional compounding, developing siliceous earth filler composite materials with multiple functions such as insulation, moisture regulation, and air purification; second, high-performance, further improving the insulation efficiency of siliceous earth filler through nanotechnology, biomimetic structure design, etc.; third, intelligence, researching temperature-sensitive siliceous earth filler systems to achieve dynamic regulation of insulation performance; fourth, greenness, optimizing the processing technology of siliceous earth filler to reduce energy consumption and emissions.

From the perspective of application expansion, siliceous earth filler has broad prospects in the following emerging markets: passive ultra-low energy building field, as a key insulation material; cold chain logistics field, used for efficient insulation of refrigerated vehicles and cold storage; new energy vehicle field, applied in the thermal management system of battery packs; aerospace field, developing ultra-lightweight siliceous earth filler-based insulation materials.

In terms of the industrial chain, the production of siliceous earth filler will pay more attention to the efficient utilization of resources and the refinement of products. Different applications have different requirements for the particle size, pore structure, purity, etc. of siliceous earth filler, and future siliceous earth filler suppliers need to provide highly customized product solutions. At the same time, establishing a unified performance evaluation standard and quality certification system for siliceous earth filler in insulation and heat preservation applications is also crucial.

Overall, siliceous earth filler, with its unique structure and performance advantages, is reshaping the technical landscape of the insulation and heat preservation material industry. With the continuous maturation of application technology and the expansion of industrialization scale, siliceous earth filler is expected to become the core component of a new generation of green insulation materials, making significant contributions to global energy conservation and sustainable development goals. Industry experts predict that by 2030, the penetration rate of diatomite fillers in the global insulation material market will increase from the current approximately 8% to 15-20%, and the market value will exceed 5 billion US dollars.