Purpose. The technology allows removing potassium and rubidium impurities from cesium iodide, thereby significantly reducing its own radiation background and producing a product of a different quality level, suitable for exclusive applications (obtaining detectors for precision experiments in high-energy physics).
Technical properties. Production capacity: 800 kg of high-purity cesium iodide per year.
Application area. Inorganic substance technology, growing single crystals.
Advantages. The technology allows processing cesium iodide into high-purity cesium iodide with reduced background radiation.
Technical and economic effect. The technology allows producing up to 800 kg of high-purity cesium iodide per year with reduced potassium and rubidium content, which is used to grow single crystals with reduced background radiation for high-energy physics. The technology is less energy-intensive than existing technologies based on multiple mass crystallization. Implementation of the technology will contribute to the creation of additional jobs.
Description. The solution of the residues of cesium iodide monocrystals is filtered and concentrated by evaporation to a cesium iodide content of 40 wt.%. The resulting solution is poured into 1.5 l polyethylene terephthalate bottles and tightly capped. Multiple low-temperature mixed crystallization (MLMC) of the cesium iodide solution is carried out at a freezer temperature of -14C. Freezing is carried out until the volume of liquid residue in the bottle reaches 50 ml. After this, the bottles are removed from the freezer, the frozen solution is crushed, the liquid residue is poured into a container with a lid, and the bottles with the frozen solution are left on the table to defrost. After defrosting the solutions, the procedure is repeated. A total of 20 MLMC cycles are carried out for each batch of solutions. The solutions after crystallization 20 are evaporated to a concentration of 130-140 g of salt per 100 g of water and cooled to a temperature of 20-25 °C. The crystalline mass of cesium iodide is dried in a forevacuum sublimation unit, packaged, sealed and labeled.