METHOD OF IMMOBILIZATION OF HAZARDOUS CONCENTRATES Russian patent published in 1999 - IPC

FIELD: environmental control, particularly, fixation of biological, chemical and radioactive wastes in stable solid medium. SUBSTANCE: method includes loading of concentrates and composition of immobilizing substances containing SiO₂, B₂O₃ and Al₂O₃ into container which serves as restrictive shell and having melting point higher than melting point of immobilizing composition; sealing of container and high-temperature treatment of mixture at temperature exceeding mixture melting point. Loading of immobilizing composition and its melting are performed prior to loading of hazardous concentrates. Included into composition of immobilizing substances are sodium oxide and added sodium fluoride with the following amounts of immobilizing substances, wt. %: Na₂O 20-25; B₂O₃ 20-25; Al₂O₃ 3-5; SiO₂ 40-45 with added NaF in amount of 7- 9. Process is carried out at temperature of 700 C. EFFECT: reliable and low-cost immobilization of hazardous concentrates.