ИСТИНА

The aim of our work was to search for organic and inorganic molecules for techJ.1etium (VII) stabilizing in а cement matrix due to poorly soluЫe complexes fonnation. Polyhexamethyleneguanidine hydrochloride (PGMG), thiourea, polyethileneimine (PEI), tryphenilphosfonium (TFF) was used as organic and various natural minerals and rocks such as: chalcopyrite, sphalerite, stibnite, bismuthin, bomite, cinnabar, pyпhotite, pyrite, scutterudite, 1narcasite, orpiment, celestine, ZnS, PbS as an inorganic. All samples with а water-cement ratio of 0.4 have passed the required strength threshold of 4.9 МРа. Samples containing PGMG; 0.1% Ьу weight of PEI; 0.5, 1 wt.%. Thiourea demonstrated а greater margin of safety than the "Ьlank" sample (22.3 МРа). lt can Ье assumed, that these additives in а certain ratio increase the safety margin of the cement compound. Samples containing 1 % Ьу weight of TFP; 0.1 wt.% Of thiourea showed the lowest tensile strength. Leaching from samples immersed in individual boxes with а solution of "Tomsk surface \\:ater" after 30 days reached the following results (ТаЫе 1): The best leaching rates (7% of the initially added [Тс04] -) after 30 days showed samples containing 1 % Ьу weight of PGMG hydrochloride, 1 % Ьу weight of PEI. Samples containing PGMG-hydrochloride showed а high margin of safety. The inclusion of the remaining stabllizing ligands worsened the mechanical characteristics of the cement matrix Ьу а factor of 1.5-2. Of the samples that did not contain stabilizing ligands after 180 days, 56% of the included technetium leached out. Based on the data oЫained, we can assume that the best stabilizing component that can Ье added to the compounds containing technetium is the РНМН hydrochloride. The study of inorganic samples sorption parameters revealed that stibnite, marcasite, sphalerite and orpiment possess the highest sorption capacity among others. Acknowledgments This work is supported Ьу RFBR project 19-03-00617 Reference [1] R.L. Russe\l, M.J. Schweiger, J.H. Westsik, Jr., et. al. Low Temperature Waste Immobilization Testing [Text] / // PNNL-16052'\ Rev. 1. -2006. -Р.21. [2] J.H. Westsik. Jr .. K.J. Cantre, R.J. Seme, N.P. Qafoku Technetium ImmoЬilization,PNNL-23329 EMSP-RPT-023.-2014.-Р.51. [3] W.W. Lukens. J.J. Bucher, D.K. Shuh, et.al Evolution of Technetium Speciation in Reducing Grout // Environmental Science and Technology. -2005.-39. -Р.8064-8070