Production of non-ferrous metal concentrate in the processing of pyrite slags

The method of preliminary chemical activation of mineral raw materials was used in the conducted studies for the complex processing of pyritic slags. The influence of preliminary chemical activation of kaolinite clays of Alexeevsky deposit in the solution of sodium hydrogen carbonate on the separation of kaolinite and quartz fractions was studied. The temperature of 150 oC, the duration of 120 minutes, and the concentration of sodium bicarbonate solution of 120 g/dm3 should be considered the optimum mode of activation. As a result of activation, the phase composition of the kaolinite fraction changed: the percentage of kaolinite fraction decreased; new phases of muscovite and sodium aluminosilicate appeared; the amount of quartz increased.

Research and development of a comprehensive technology for processing kaolinite clays in Kazakhstan

In the Republic of Kazakhstan, the most promising are kaolinite clays of the Alekseevsky deposit. For effective processing of clays, it is necessary to develop special methods of processing, since satisfactory results were not achieved when using standard methods of gravity processing. The article provides the results of studies of the effect of preliminary chemical activation on the yield of the kaolinite fraction during gravitational processing. Previously, the method of preliminary chemical activation of raw materials in a solution of sodium bicarbonate has proven itself well in the processing of various mineral raw materials. It is determined that as a result of preliminary chemical activation, changes in the phase composition occurred. The dependence of the yield of the kaolinite fraction on the temperature of chemical activation, duration, and the ratio of W:T and the concentration of the sodium bicarbonate solution. Based on the results obtained, a technology for the complex processing of kaolinite clays has been developed, which provides for the preliminary chemical activation of the feedstock at the beginning of the process, which will effectively isolate high-quality kaolinite and quartz products, which will significantly reduce the flow of materials entering for sintering. As a result of activation, the phase composition of the kaolinite fraction has changed: the percentage of the kaolinite fraction has decreased; new phases of muscovite and sodium aluminosilicate appeared; the amount of quartz increased.

Remediation of Annular Gas Migration along Cemented Wellbores Using Reactive Mineral Fluids: Experimental Assessment of Sodium Bicarbonate and Sodium Silicate-Based Solutions

Achieving zonal isolation along wellbores is essential for upholding the containment integrity of subsurface reservoirs and preventing fluid seepage to the environment. The sealing performance of Portland cements conventionally used to create barriers can be severely compromised by defects like fractures or micro-annuli along casing–cement–rock interfaces. A possible remediation method would be to circulate reactive fluids through compromised cement sections and induce defect clogging via mineral precipitation. We assess the sealing potential of two prospective fluids: sodium bicarbonate and sodium silicate solutions. Reactive flow-through experiments were conducted on 6-m-long cemented steel tubes, bearing ~20-μm-wide micro-annuli, at 50 °C and 0.3–6 MPa fluid pressure. For the sodium bicarbonate solution (90 g/kg-H2O), reactive flow yielded only a minor reduction in permeability, with values remaining within one order. Injection of sodium silicate solution (37.1 wt.%, SiO2:Na2O molar ratio M= 2.57) resulted in a large decrease in flow rate, effectively reaching the setup’s lower measurement limit in hours. However, this strong sealing effect can almost certainly be attributed to gelation of the fluid through polymerisation, rather than defect clogging via mineral precipitation. For both fluids investigated, the extent of solids precipitation resulting from single-phase injection was less than anticipated. This shortfall is attributed to ineffective/insufficient liberation of Ca-ions from the alkaline phases in the cement.

Processing of formate solutions obtained from red mud leaching

The paper determines the indicators of the developed process flow for the complex processing of red sludge via the formate method: recovery of components; yield and composition of products when processing a sample of formate solution obtained from red mud leaching. The conducted experiments used red mud generated in the production of alumina at the Urals Aluminium Smelter. The samples of formate solution obtained in the course of red mud leaching were analyzed using an Optima 8000 ICP-OES Spectrometer, a Sartorius MA-30 Moisture Analyzer to measure moisture content, as well as an ARL 9800 XRF Spectrometer to ascertain the mass fraction of elements in metal and nonmetal specimens found in one of three states (solid, liquid, or powder). These experiments were performed while continuously measuring and monitoring pH values by means of a pH meter having a thermal compensation function. The performed experiments involved the total recovery of valuable elements from formate solutions produced during red mud leaching. A concentrate containing Al, Sc, and rare earth elements (REEs) was processed to produce scandium oxide and rare earth metal concentrate (after dissolving aluminum in an alkali). Rare earth metals and scandium were shown to concentrate in the solid phase; scandium was then selectively leached with a sodium bicarbonate solution to form water-soluble carbonate complexes [Sc(CO3)4]5- having carbonate ions СО32- and НСО3-. When using the proposed technology, the overall recovery of scandium and REEs amounts to 98–99%, whereas that of aluminum, calcium formate, and sodium formate from the produced solution reaches 99%. The processing of formate solution yields the following end products: scandium oxide (99 wt% Sc2O3) and REE concentrate (content of 56.1%). The paper demonstrates the possibility in pri nciple to process solutions obtained from the flow-through leaching of red mud via the formate method.

Kaolinite clays as a source of raw materials for the aluminum industry of the Republic of Kazakhstan

Kaolinite clays can serve as an additional source of alumina in the Republic of Kazakhstan. The most promising is the Alekseevsky kaolinite deposit. To obtain high-quality kaolinite and quartzite products, it is necessary to develop special enrichment techniques, since no satisfactory results were achieved when using standard methods of gravitational enrichment of kaolinites. The paper presents the results of studies of the effect of preliminary chemical activation during the processing of kaolinite clays of the Alekseevsky deposit. Previously, the method of preliminary chemical activation of raw materials in a solution of sodium bicarbonate has proven itself well in the processing of various mineral raw materials. It was determined that during the preliminary chemical activation in a solution of sodium bicarbonate, changes occurred in the phase composition of the kaolinite fraction: the content of muscovite decreased almost twice; the phase of sodium aluminosilicate was formed. The dependence of the yield of Al2O3 in the kaolinite fraction on the temperature of chemical activation, duration, and the ratio of L:S and the concentration of the sodium bicarbonate solution during chemical activation. The optimal mode of preliminary chemical activation of kaolinite clay of the Alekseevsky deposit has been established: the temperature is 150 oC, the duration is 120 minutes and the concentration of sodium bicarbonate solution is 120 g/dm3. A basic technological scheme is proposed for the processing of kaolinite clays.

Comprehensive study of the toothpaste containing fluoride and 67% aqueous sodium bicarbonate solution

Relevance. A wide variety of oral care products is available nowadays. Sometimes aggressive advertising rather than doctor’s advice determines our patients’ choice. In our research, we provide evidence of the clinical use of toothpaste containing fluoride and sodium bicarbonate.Materials and methods. During four weeks, we followed up a group of students who used the toothpaste containing 1400 ppm fluoride and 67% aqueous sodium bicarbonate solution. The clinical, biochemical and microbiological tests and saliva crystallization score assessed the characteristics stated by the manufacturer.Results. The statistically significant correlation between all studied criteria is evidence of the effectiveness of the toothpaste. In addition to the significant remineralization and antiplaque effect, biochemical and microbiological tests confirmed the anti-inflammatory effect of the toothpaste. An immediate cleaning effect was observed after the first brushing as well as in long-term use.Conclusion. Improvement of oral hygiene indices and reduction of periodontal inflammation confirmed the successful result of the comprehensive treatment of chronic gingivitis.