This invention discloses a method for preparing high-density, high-purity polycrystalline barite polymers under
hot isostatic pressing conditions, wherein barite sample
powder is compacted and sealed to a vacuum degree of 10. –3 The sample was placed in a steel cladding with dimensions of 55.89 mm outer
diameter × 88.76 mm height × 3 mm wall thickness. The cladding was then placed inside the
graphite furnace cylinder of a hot isostatic
pressure vessel and sealed with a
graphite cap. Using
argon as the pressure transfer medium, a multi-gradient cylinder heating and pressurization method was employed to raise the temperature inside the
sample chamber to 950 °C and the pressure to 112.5 MPa. This pressure and temperature were maintained for 6.0 hours. A multi-gradient cylinder cooling and depressurization method was then used to lower the temperature inside the
sample chamber to 178 °C and the pressure to 71.1 MPa. The pressure was then released and the sample was cooled to
room temperature to obtain a polycrystalline barite
polymer. This method filled the technical gap in the preparation of bulk
sulfate experimental samples of high-density polycrystalline barite polymers under high temperature and
high pressure conditions.