National Mineral Resources University, Saint Petersburg, Russia

V. I. Bolobov, Professor of a Chair of Mechanical Engineering, e-mail: Boloboff@mail.ru

“Scientific and Research Center “Gidrometallurgiya” LLC, Saint Petersburg, Russia

Ya. M. Shneerson, Chief Executive Officer, Professor
A. Yu. Lapin, Technical Officer

In the laboratory autoclave and continuous pilot plant products in the environment of high temperature oxidation of pyrite gold concentrates (t = 225 ^оC, P_O2 = 0.7 MPa, the total pressure in the gas phase Р_Σ = 3.3 MPa, ~3–6% solution Н₂SO₄) using the gravimetric and metallographic methods analyzes the corrosion behavior of the samples, including welding, 6- and foreign brands of alloys (Inconel 625 and Hastelloy In G35, BC1, C2000, C276, C22) systems doping Cr – Ni – Mo and Cr – Ni – Mo – Cu, and Cr – Ni – Mo – Cu-steel 904L (equivalent EI943 (ЭИ943)). Despite the formation of difficult to remove the shell of the crust that forms on the motion of the pulp samples to set up, the rate of corrosion K to materials in products of high-temperature oxidation leaching of pyrite materials in a laboratory autoclave and pilot plant is almost identical. The value of K for all tested alloys and steel in liquid leachate is significantly higher than in the gas. In the pulp, the maximum corrosion resistance observed in Hastelloy G35 welded joint (K < 1.0 mm/year — stable material), minimum — in Hastelloys BC1, C276, C2000, C22 (R > 10 mm/year — unstable materials). An intermediate position is Inconel 625 and steel In 904L (1,0 < K < 3.0 — reduced resistant materials). According to the results of metallographic analysis Hastelloy G35 intergranular corrosion in production of high-leaching process is not affected. High corrosion resistance of Hastelloy G35 authors to the high content of chromium in the alloy (~33%).

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