METHOD OF MANUFACTURING ARTIFICIAL SELLAITE Russian patent published in 1997 - IPC

FIELD: manufacture of optical materials, more particularly technology of manufacturing half-finished optical ceramic articles for inlet ports, lenses and other optical members for infrared spectral region. SUBSTANCE: method comprises depositing magnesium fluoride from aqueous magnesium carbonate suspension with hydrofluoric acid, adjusting pH of mother liquor to 4.2-5.0, adding one molar aqueous ammonium fluoride solution, separating the deposit, drying the resulting powder, heat treating it in the air, briquetting the powder at pressure not higher than 20 MPa in vacuum at 200-280 C for not longer than 30 minutes, subsequently heating it at rate of 20-40 C and hot pressing the briquette and applying pressure of 198-196 MPa at 760-800 C. EFFECT: wide region of transparency and improved mechanical strength. 1 dwg, 1 tbl