Processing of low quality ekibastuz coals ashes and natural diatomites to obtain alumina and foamed glass

Analysis of technological solutions on complex processing Ekibastuz coals ashes displays efficiency of complex alkaline technologies. However their significant drawback is the necessity to utilize big volumes of alkaline-silicic solutions. This research demonstrates possibility of their rational utilization by using natural raw diatomites to obtain formed and pelleted foamed glass widely used in construction industry as a heat-insulating material. Based on the data from scientific literature and their own research the authors suggest an improved scheme of complex processing Ekibastuz coals ashes

Kinetics of roasting of copper and iron sulfides with soda in a vibratory boiling layer

The kinetics of the roasting of iron and copper sulfides in a pulsating layer was studied, and the kinetic parameters of the processes were determined. The determination of the order of the roasting reactions and activation energy in the MeS – Na2CO3 - O2 system is based on the differential method. Using the dependences of the degree of conversion of copper and iron sulfides in the reactor of the vibratory pulsating layer at a pulsation frequency of 50 Hz and a pulsation amplitude of 0,1 - 0,5 mm, the values of the apparent activation energy in the temperature ranges of 500 – 550 - 600 °C were obtained for FeS 1,60 - 1,64 and for Cu2S 1,44 - 2,41 J*mol. (CO2)

Research on sorption properties of phosphoric production slag-waste

On the territory there are phosphorus-containing wastes - phosphorus slags, the basis of which is volostanite. The study of phosphorus slag as a uranium sorbent is of theoretical and practical interest. In the course of the research, comparable data were obtained on the sorption of the initial and activated slag by different reagents. The optimal conditions for the activation of phosphorus slag in order to increase its sorption properties have been determined

Revisiting the Kazakhstan natural sorbents modification

Kazakhstan ranks second in the world in natural uranium reserves and a leading position in its production. Hydrometallurgical processing of uranium raw materials results in a significant amount of liquid technogenic wastes containing radionuclides. Sorption cleaning methods for these wastes are the most effective ones. However, the high cost of synthetic sorbents and the low sorption capacity of natural ones is a deterrent to their use. So, to increase the sorption capacity of natural sorbents by their modification is an urgent problem. In this paper, a method to modify Kazakhstani natural zeolite was proposed by us and previously not investigated. Also the data of physicochemical studies of the initial raw material and the modified product was given and the increase in the natural sorbent specific surface in the modification process was demonstrated

Metallurgical and Mining Industry Chemistry of metals Metallic sulphide and sodium carbonate interacting processes

Abstract The article deals with a review of publications and patents on interacting mechanisms of sodium and potassium carbonate -hydroxide with nonferrous sulfides\ iron in neutral and oxidizing medium. Nonferrous sulfide like lead sulfide is reduced to metal in inert atmosphere or in the presence of carbonaceous reducing agents, alkali metals form sodium and potassium sulfides. Soda and sulfate melting techniques were tested on an industrial scale but were not widely used. Some technologies use smelting sulphidic materials in molten alkali with the delivery of oxygen containing gas. These technologies allow to recover sulfides of lead, copper, nickel and iron to metal at low temperatures from 340-350°C up to 600-700 o C. Sulfides of these metals transit to sodium and potassium sulfates in the presence of oxygen. The given technologies are environmentally friendly due to no release of sulfurcontaining gases. The interaction of nonferrous and iron sulfides with sodium and potassium carbonate is little -studied. Patent 4,541,993 (USA) offers joint sulphatization roasting of sulphide ores and carbonate or bicarbonate of alkali metals for extracting non-ferrous metals (copper, nickel, cobalt and zinc). Studies of the behavior of PbS, Cu 2 S, Bi 2 S 3 FeS 2 in molten salt of Na2CO3-NaCl showed that PbS when reacting with Na 2 CO 3 forms PbO and the reaction of PbO and PbS forms lead. The research is aimed at analyzing thermodynamic systems MeS-O 2 -Na 2 CO 3 ; determining the temperature of initial reactions of sodium carbonate with sulfides of copper, lead, zinc and iron; studying the extent of Cu 2 S desulfurization at adding sodium carbonate in the mix material and air inlet or delivery under the filter layer. The study included the use of sulfides and natural minerals produced by synthesis, the X-ray analysis of raw materials and products produced by the method of synthesis, chromatographic analysis of gases on carbon dioxide content. The composition of exhausted gases was monitored during a continuous heating of a test charge at the heating rate 10 K/min. It enabled to reveal the initial stage of desulfurization of copper, iron, lead and zinc sulfides, possibly caused by the change of homogeneity field of the sulfide composition. At the known processes the oxidation order of simple non-ferrous sulphides proceeds as follows: FeS, ZnS, PbS, Cu 2 S. This sequence changes in the presence of sodium carbonate and oxygen: Cu 2 S (415-430 o C), FeS 2 (490-515 o C), FeS (530-545 o C), PbS (545-560 o C), ZnS (735-750 o C). At mix material roasting consisting of copper sulfide we used planning experiment methods. There were found partial dependences between the effect of temperature and duration of the experience on the desulfurization degree. They are presented in the form of straight line equations, isochor for desulfurization extent from 36.6 to 84.4% and at temperatures 500-600 o C. The air flow rate and the flow rate of soda used in experiments were close to the theoretically necessary figures and when the degree sulphide conversion was reached, they had no significant effect. The dependence of these factors is described by the mean value. The maximum desulfurization degree is achieved at a greater burning time and temperature. Leaching and thermodynamic analysis of a roasted product allowed to determine that oxide Cu 2 O and 27 Metallurgical and Mining Industry No.11 -2015 Chemistry of metals CuO were the main products of copper sulfide burning in the presence of sodium carbonate and delivery of oxygen-containing gas