Exploring the Advantages of Neutral Ramming Mass (NRM) Solutions

In metallurgical engineering, particularly in induction furnaces, the focus is on a comparative analysis between NRM and silica to maximize efficiency and safety of your installation. This article expands on neutral ramming masses (NRM), specifically, the solutions provided by Saint-Gobain under our HeatKing/NORTON brand, delineating its advantages over conventional materials like acidic (silica Based) ramming mass. This is applicable for all kinds of charge mixes like DRI (pellets/lumps/fines), Steel scrap (all kinds), direct melting of Stainless steel or other alloys and any capacity of coreless induction furnace.  

Benefits EHS (Environment, Health, and Safety)

1. Reduction of silica-related Hazards: The first benefit of using NRM is about Health. In fact, NRM does not contain crystalline alveolar silica. This Silica dust, known to cause severe lung diseases, poses significant health risks in industrial environments. The Occupational Safety and Health Administration (OSHA) regulation 29 CFR 1926.1153 strictly regulate silica dust exposition, underscoring the danger. NRM's composition circumvents this hazard, offering a safer alternative for industrial applications.
2. No Soil Pollution and Sustainable Usage: Traditional silica waste hampers the fertility of land because of its nature. Conversely NRM does not affect fertility if dumped in open soil. Silica has very limited usages of recycling whereas NRM can be fully recycled and reused for other application after full usage in induction furnace. This reusabilityis including less waste generation and, as a consequence, less landfiling and soil pollution.
3Safe uf use thanks to the three-phase structure and high refractoriness: The progressive three-phase structure formation in application, which remains a safety powder back up, allows to stop the metal infiltration and thus prevent from any metal contact with the coil

General Advantages

Optimized Storage Requirements

Optimized Storage Requirements: The longer lifetime of NRM in service allows to reduce relining and maintenance frequency. By extension, this means less material to be stored on-site, and to optimized space in storage facilities.

Reduced Operational Breakdowns

Reduced Operational Breakdowns: The robustness of NRM translates to fewer breakdowns in furnace operations, enhancing overall productivity and reducing unexpected downtime.

Ease of Preventive Maintenance

Ease of Preventive Maintenance: The durability of NRM facilitates preventive maintenance in alternate crucibles, ensuring continuous operation with minimal disruptions.

Labor and Time Efficiency

Labor and Time Efficiency: The extended service life of NRM allows to, reducing the frequency of maintenance and replacement operations. This efficiency enables to allocate human resources to other critical tasks.

Quality Improvement

Steel which is produced using NRM lining was found to be cleaner compared to production using other ramming mixes. 

Microscopial observations of metallic infiltration - "cup test":
The "cup test" is used to study the metallic infiltration in NRM materials. The process is as follows: the monolithic refractory material (NRM) is pressed into a brick shape with a small cavity in the center. This cavity is then filled with the studied metal. This assembly is heated to temperature for a few hours to melt the metal. Next, the brick is cut in half and the infiltration of the metal into our NRM compared. The less infiltration, the better! Smaller pieces can also be cut to examine the metal infiltration under the microscope.

observation of copper infiltration in NRM

Cost Advantages


ferro alloys saving
Energy saving
Extra Product

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Neutral ramming mass solutions, particularly those offered by Saint-Gobain under the HeatKing/NORTON brand, present a paradigm shift in the lining of induction furnaces. Their superior safety profile, environmental benefits, operational efficiencies, and health advantages position them as a preferable alternative to traditional silica-based linings. 

As industries continue to evolve towards safer, more sustainable, and more efficient practices, adopting NRM is a testament to technological advancements in refractory solutions.


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