NITROCELLULOSE PRODUCTION PROCESS

Alpenfalke-Nitrocellulose

Nitrocellulose production involves a meticulous chemical process, primarily focusing on treating cotton or wood-based cellulose with a controlled mixture of nitric and sulfuric acids to create products like guncotton (with a nitrogen content of 13.35-13.45%) and pyrocellulose (with a nitrogen content of 12.6-12.7%).

  1. Acid Mixture Preparation
  • Nitric Acid Production: Ammonia is vaporized and reacted with air over a platinum-rhodium catalyst to produce nitrogen oxides. These gases are absorbed in distilled water, creating nitric acid with a concentration of 60%.
  • Sulfuric Acid Production: Sulfur is burned to generate sulfur dioxide, which is further processed into sulfur trioxide and absorbed in water to produce sulfuric acid. The sulfuric acid stabilizes the reaction by preventing dilution of nitric acid during the process.
  • Blending: Weak nitric acid and sulfuric acid are mixed and distilled to concentrate their strength. The final acid blend, used for cellulose nitration, typically consists of one part nitric acid to three parts sulfuric acid by weight.
  1. Preparing Cellulose

Cotton linters or wood pulp are shredded and dried to minimize moisture content to less than 1%. The prepared material is transferred to the nitration stage.

  1. Nitration Process
  • Mixing: Cellulose fibers are combined with a concentrated acid mixture in specialized nitrators. The resulting nitrocellulose and spent acids are separated and further processed.
  • Boiling and Washing: Repeated hot water washes remove residual acids and impurities, ensuring product stability and uniformity.
  • Pulping: Fibers are cut into smaller fragments using machinery to expose impurities for effective removal.
  • Neutralization: Additional washing in alkaline solutions eliminates remaining acidity, followed by thorough rinsing to meet quality standards.
  • Blending: Nitrocellulose batches are screened, blended, and checked for uniformity before moving to the next stage.
  1. Final Processing
  • Dehydration and Solvent Treatment: Residual water in nitrocellulose is replaced with alcohol to prepare it for further chemical processes.
  • Mixing and Stabilization: The material is mixed with ether and stabilizers to ensure durability and storage safety.
  • Shaping: The nitrocellulose is pressed and extruded into desired forms, such as strands or sheets, depending on the application.
  1. Waste Management

Throughout the production process, wastewater is carefully treated to recover nitrocellulose fibers and neutralize residual chemicals. Efforts are made to recycle water and minimize environmental impact.

This detailed production methodology ensures the consistent quality and safety of nitrocellulose, meeting the highest industrial and military standards.