A. H. Dyshekova, A. M. Karmokov

The nonlinear temperature phenomena in thermodynamics are shown near to phase transitions of the first or second sort and closely connected with self-organizing processes. In the present article the experimental research of nonlinear features of temperature dependences of such thermodynamic characteristics, as a contact angle, interphase tension, adhesion energy for a system example «sodium chloride - liquid lead» is spent. In the course of alkaline refinement of lead sodium chloride is used. There is no common opinion about the mechanism of interaction of the given pair substances in the literature. In the given work orientation dependence of contact angle of liquid lead on chloride sodium monocrystals in the range of temperatures 350−720 °С is investigated. Research of contact angle temperature dependence was spent on a method of a lying drop. The liquid lead contact angle on a surface of monocrystal NaCl of orientation (100), (110) and (111) with rise in temperature decreases linearly. However, in the range of temperatures 650-720 С the given dependence gets a nonlinear course. Experiment shown, that contact angle orientation dependence decreases among (100), (110), (111) accepting the least value for a side (111). The interphase tension on border of monocrystal NaCl with liquid lead with temperature growth has similar character. In a range 650-720 С contact angle temperature dependence deviates temperature from linear and has recession. The contact angle and interphase tension on border of chloride of sodium with liquid lead change proportionally surface atom density. Using the received values of a contact angle and a superficial tension, the assessment of adhesion energy of lead to different sides of chloride of sodium is spent. To clearing technology of lead from impurity chloride of sodium of crystallographic orientation (111) is represented to the most preferable.