Traditional technologies of gold mining are exhausted due to the depletion of stocks of conditioned raw materials at functioning gold mining enterprises, in addition, the preservation or disposal of large-scale waste of these technologies requires significant financial costs for environmental protection measures. Recently, the search for alternative methods of gold leaching, which involve the use of non-toxic factors, but which in their physicochemical properties can compete with traditional levels, and especially with cyanides. The authors of this work investigated the mechanism and kinetics of the process of dissolving metallic gold in chloride-hypochlorite solutions and believe that alkali metal hypochlorites (first of all, sodium hypochlorite NaOCl, which is easily obtained by electrolysis from a solution of food’s salt NaCl, or from sea water) are a very promising replacement for cyanide-containing leachates. Two series of experiments were carried out to study sodium hypochlorite as a gold leaching agent using a traditional gold disk and finely dispersed native gold as dissolution objects. Found fundamental differences in methodological techniques when working with a traditional model object and native gold. The dependences of the dissolution rate on the solution pH, sodium hypochlorite concentration, and temperature are determined. Conditions of the gold surface passivation during its dissolution are discussed. The first-order rate constant of the gold dissolution 1 0,079 - 0,4030  ki  h at temperatures from 277 K to 304 K and others are calculated. The activation energy from the temperature dependence of the rate constants (40,3 kJ/mol) evidences a diffusion-kinetic control of the gold dissolution. Electron microscopy (using electron probe scanning on an energy dispersive spectrometer) of native gold particles revealed foreign inclusions - adsorbed mineral particles of calcite (CaCO3) and, presumably, a surface film consisting of aluminum oxide (Al2O3), which create a significant obstacle to the contact of leaching agents with the surface of the target gold grains. Quantitative data on the composition of surface adsorption films, formed by model gold electrode dissolution products, are obtained using atomic adsorption spectroscopy.

X-ray spectral studies of the chemical composition of Irshansk ilmenite concentrates showed that it is leukoxenized mineral with a high (up to 79%) content of titanium oxide and inclusions of pseudorutile. The process of alkaline leaching of Ti4+ from ilmenite is investigated in the work. The study of the temperature effect on the reaction of ilmenite with potassium hydroxide at atmospheric pressure revealed that a temperature of 453 K is sufficient to obtain potassium titanate. A further increase in temperature does not provide a significant increase in the yield of water-soluble titanium. It is found that the optimal and sufficient ratio between ilmenite and potassium hydroxide is 1:2. An increase in the amount of potassium hydroxide in the reaction mixture is unsuitable, since it reduces the yield of soluble titanium and the final product will have a high alkalinity due to the presence of alkali which did not react. The main process of leaching with the formation of solid melt is completed in the first 30 minutes of the process. Infrared spectroscopy and X-ray diffraction showed that potassium titanate (K2TiO3) is formed under the studied conditions of alkaline leaching of ilmenite.

22. Π опуляционный и семейный анализ методом блот-гибридизации полиморфизма сайтом ДНК, сцепленных с геном муковисцидоза / О. В. Воронина, В. С. Гайцхоки, Т. Э. Пващепко и др. // Биополимеры и клетка.-1990.-6, № 2.-С. 65-71. 23. Молекулярная природа некоторых мутаций как причин фенилкетонурни в популяциях СССР/В. Н. Калинин, Е. И." Шварц, Б. В. Скрябин и др.//Тез. докл. II Всесоюз. съезда мед. генетиков.-Алма-Ата, 1990.-С. 17. 24. Молекулярная природа делеции при Р°-талассемии, установленная с помощью метода амплификации геномной ДНК in vitro j Ε. И. Шварц, А. А. Гольцов, О. К. Koбоев и др.//Биоорг. химия.-1989-15, № 4-С. 556-559. 25. Характер двух мутационных повреждений р-глобинового гена при р°-талассемии в Азербайджане / А.

The thermodynamics of the alkaline leaching of ilmenite was investigated in this work. Thermodynamic parameters (enthalpy, entropy, Gibbs energy, etc.) are important and necessary for understanding both the course of the chemical reaction as a whole and the possibility of its implementation in the production process. The change in Gibbs energies at different temperatures during the chemical reaction of ilmenite leaching was calculated by the Temkin-Schwartzman method. The calculated values of the Gibbs energies of the reactions for the production of sodium and potassium titanates allowed us to state that the interaction of ilmenite with potassium hydroxide is energetically more advantageous. With the help of X-ray diffraction studies, it was established that ilmenite from the Irshansky deposit is leukoxenized. The identification of the main reflexes of the diffraction patterns confirmed that the interaction of potassium hydroxide and ilmenite yields potassium titanate.