Determination of Optimal Fluorine Leaching Parameters from the Coal Part of the Waste Lining of Dismantled Electrolytic Cells for Aluminum Production

When aluminum is obtained by electrolysis of cryolite-alumina melts when the baths are sent for  capital repairs, a solid technogenic product is formed – waste lining of electrolytic cells (WLEC). The volume of formation of WLEC is 30-50 kg per 1 ton of aluminum. Currently, it is mainly stored at landfills near industrial enterprises, causing harm to the environment. However, this technogenic raw material contains valuable components (fluorine, aluminum, sodium) that can be extracted to produce fluoride salts, which are in demand during the electrolytic production of aluminum. The objects of research were samples of the coal part of the waste lining of dismantled S-8BM (E) type electrolytic cells of «RUSAL Krasnoyarsk» JSC (Krasnoyarsk) of RUSAL company. According to the X-ray experiment diffraction analysis (using a Bruker D8 ADVANCE diffractometer) of the phase composition of the samples, it was found that the main fluorine-containing compounds are cryolite, chiolite, sodium and calcium fluorides. The total fluorine  content  in  the  studied  samples  averaged  13.1  %.  We  conducted  studies  on  the  leaching  of fluorine from WLEC with a solution of caustic alkali (NaOH concentration – 17.5 g/dm3). The process was  carried out in a mechanically agitated reactor using a BIOSAN MM-1000 top drive laboratory stirrer with a two-blade nozzle. By the method of mathematical planning of a three-factor experiment, the mutual influence of three leaching conditions on the optimization parameter was established – the extraction of fluorine in solution (in percent). The maximum recovery of fluorine from WLEC to the leach solution averaged 86.4 % and was achieved with the following indicators:processtemperature–95°C,theratio ofliquidtosolidphase–9:1,duration– 210 min

The Commercialization of Genetic Research: A Pilot Study

With the development of molecular genetics, the field of personalized medicine based on genetic data has been growing at a phenomenal pace. Genetic tests can identify health risks, ancestry, and genealogy, as well as the prediction of drug responses. However, very limited research exists about the marketing practices of companies, which promote and sell DNA ancestry and health-related genetic tests directly to the public.Aim. To evaluate the awareness and attitude about genetic testing in the population of a large industrial city in Russia (on the example of Irkutsk).Materials and methods. A total of 305 respondents – 265 of them were students of higher educational institutions of Irkutsk. The study was conducted on condition of anonymity. The questionnaire was available on the Internet on the basis of the Google Forms service. All basic concepts were explained to the participants during the survey.Results. 94.1 % are interested in conducting genetic testing on a commercial basis. Of the total number of survey participants, 72.8 % expressed a desire to undergo the analysis “Hereditary predisposition to diseases”, 61 % – “Monogenic diseases”, 52.1 % – “Ethno”. In addition, out of the total number of respondents surveyed, 36.7 % want to undergo genetic testing for research: features of metabolism and food intolerance “Diet”, 22 % – susceptibility to injuries and speed of recovery of physical form “Sport”, 18 % – to hereditarily determined susceptibility to drugs “Pharmacy”. It follows from the answers that the greatest interest among the surveyed people is the determination of predisposition to cardiovascular diseases – 72.5 %, to Alzheimer’s disease – 48.3 % and diabetes mellitus – 40.3 %.Conclusion. The results obtained indicate an interest in the study of predisposition to cardiovascular and neurodegenerative diseases. There is a high need to analyze the assessment of the clinical usefulness of genetic research, to assess the impact of research results on human behavior and the system of regulation of genetic testing in healthcare in general

Assessment of reference intervals of acylcarnitines in newborns in Siberia

Background. The incidence of diseases associated with impaired transport and oxidation of fatty acids is from 1:5,000 to 1:9,000 newborns. High morbidity, risk of death in the absence of timely correction, non-specificity of clinical manifestations define the importance of their timely laboratory diagnosis based on the determination of free carnitine and acylcarnitines in the blood. Reference values for free carnitine and acylcarnitines vary in different populations.   The aim. To determine the reference intervals of free carnitine and acylcarnitines in newborns of the Irkutsk region and to compare them with similar reference intervals in newborns in other countries.   Methods. The analysis of 229 samples of drу blood spots of healthy newborn children of the Irkutsk region aged from 0 to 7 days was carried out. Analysis of acylcarnitine concentrations was performed using high performance liquid chromatography with tandem mass spectrometry.   Results. 2.5 and 97.5 percentiles (µmol/l) were calculateed for 13 acylcarnitines: C0 – [8.78; 38.08]; C2 – [3.55; 19.09]; C3 – [0.33; 1.96]; C4 – [0.08; 0.51]; C5 – [0.06; 0.44]; C5DC – [0.03; 0.17]; C6 – [0.01; 0.07]; C8 – [0.01; 0.07]; C10 – [0.02; 0.07]; C12 – [0.04; 0.51]; C14 – [0.07; 0.24]; C16 – [0.58; 3.25]; C18 – [0.35; 1.16].   Conclusion. Differences in acylcarnitine reference intervals were found: compared with other countries, the concentrations of reference intervals for C0, C2, C3, C5DC, C8, C10, C14, C16 and C18 were lower in our study, reference intervals for C5 and C12 were higher in our country

EXPERIENCE OF INTEGRATED USE OF GOLD-BEARING RAW MATERIAL IN THE PRODUCTION OF PRECIOUS METALS

With the depletion of rich gold-bearing ores, the processing started to use polymetallic ores, which, in addition to precious metals, contain other elements that could be valuable after recovery. The problem of using such ores is extremely difficult because of the high cost of recovery of associated valuable components. The paper presents the results of studies on the integrated use of extracted gold-bearing raw materials based on the example of the Berezitovoye deposit (Amurskaya oblast), they have low content of precious metals and many heavy non-ferrous metals (copper, lead). Experimental work was carried out to obtain copper by the method of cementation from solutions formed after the leaching of the impurities of gold-containing cathode deposits with hydrochloric acid. The cementing metal was iron turnings (waste products of the turning shop of the enterprise). Next, it was proposed to use cemented copper as a collector during re-melting of slags – wastes of processing of low-grade polymetallic ores containing precious metals. The authors obtained ingots of alloyed gold with gold weight fraction of 16 %, which meets the requirements of TU 117-2-7-75 on the content of non-ferrous metals. During hydrochloric acid treatment of cathodic deposits silver partially passed into the solution, it was recovered together with cemented copper and, in subsequent melting, passed into alloyed gold. Thus, the method proposed by the authors helps to reduce the content of precious metals in the «incomplete production cycle» of the gold recovery factory. The opportunity of selling the cementation copper at the enterprises specializing on manufacturing of jewels is shown, the expected economic effect at the same time amounted to more than 1.8 million rubles

Кинетическая оценка возможности восстановления алюминия и магния из водных растворов их солей как альтернатива электролизу расплавов

In the non-ferrous metal industry a unique position is given to electrolytic production as being one of the most energy-consuming and environmentally dangerous technologies. Thus, for example, obtaining aluminum by cryolite-alumina melt electrolysis is accompanied by the atmospheric emissions of fluorine-, sulphur-containing substances and hydrocarbons, and magnesium production – by the emission of chlorine and organochlorine compounds. By present time those suggestions in terms of aluminum and magnesium production are considered relevant that are aimed at improving the environmental situation in the vicinity of metallurgical plants. Despite the fact that existing aluminum and magnesium production technologies are under favorable conditions for development and can be really adopted at existing plants, there are ideas and suggestions appearing to create new technologies based on scientific advances in electrolytic light metal production. The authors used magnesium and aluminum as research objects. They considered interaction between metals and aqueous solutions of their salts – MgSO4, MgCl2, Al2(SO4)3, AlCl3 chlorides and sulfates. It is shown that such interactions always take place in a diffuse area that provide for using various design solutions when selecting the process instrumentation. Experimental data were used to determine the reaction order with respect to the solvent, speed and activation energy constants. The results prove the assumption that it is preferable to use chloride media facilitating the process course based on primary electrode reactions and excluding any auxiliary interactions. It is demonstrated that chloride solutions can serve as operating electrolytes and can carry the recovered metal ions. At the same time electrolytic saturation guarantees the impossibility of a reversible process – secondary metal melt which leads to reducing the main indicators of cryolite-alumina melt electrolysis.В металлургии цветных металлов особое место занимают электролитические производства, относящиеся к наиболее энергоемким и экологически небезопасным технологиям. Так, например, получение алюминия электролизом криолит-глиноземных расплавов сопровождается выбросами в атмосферу фтор-, серосодержащих веществ и углеводородов, производство магния – хлора и хлорорганических соединений. К настоящему времени актуальными следует считать любые предложения в области производства таких металлов, как алюминий и магний, направленные на улучшение экологической ситуации вблизи расположения металлургических предприятий. Несмотря на то, что совершенствование существующих технологий получения алюминия и магния имеет благоприятные тенденции развития и реальные возможности внедрения на действующих предприятиях, возникают идеи и предложения по созданию новых технологий на основе научных достижений в области электролитического производства легких металлов. В качестве объектов исследования применяли магний и алюминий. Рассмотрено взаимодействие металлов с водными растворами их солей – хлоридами и сульфатами MgSO4, MgCl2, Al2(SO4)3, AlCl3. Показано, что такие взаимодействия всегда протекают в диффузионной области, что открывает возможности использования различных конструктивных решений при выборе аппаратурного оформления процесса. На основе экспериментальных данных найдены порядок реакции по растворителю, константы скорости и энергии активации. Полученные результаты доказывают предпочтительность применения хлоридных сред, обеспечивающих протекание процесса на основе базовых электродных реакций и исключающих возникновение побочных взаимодействий. Показано, что хлоридные растворы могут служить рабочими электролитами и быть носителями ионов восстанавливаемого металла. При этом насыщение электролита является гарантией невозможности обратимого процесса – вторичного растворения металла, что приводит к снижению основных показателей процесса электролиза криолит-глиноземных расплавов

Low-Modulus Cryolite Production Methods Using Anode Gas Cleaning Solutions of Aluminum Smelting

В статье исследованы способы промышленного производства низкомодульного криолита (НМК). Первый способ – получение НМК путем кристаллизации хиолита и фтористого алюминия. Экспериментальные данные показали возможность получения как фтористого алюминия, так и низкомодульного криолита из кислых растворов газоочистки. Второй способ – получение НМК путем обработки регенерационного криолита растворами газоочистки с добавлением водной суспензии гидроксида алюминия. По результатам лабораторных исследований доказана возможность получения вторичного криолита с заданным криолитовым отношением (КО) за счёт изменения технологических параметров отмывки регенерационного криолита. Авторами также были проведены опытно-промышленные испытания отмывки регенерационного криолита гексафторалюминиевой кислотой, полученной в промышленных условиях с использованием ингибиторов коррозииThe article deals with the methods of low-modulus cryolite production (LMC). The first method is to produce LMC by chiolite and aluminum fluoride crystallization. The experimental data indicated that both aluminum fluoride and LMC can be produced from acid gas cleaning solutions. The second method is to produce LMC by handling regeneration cryolite with gas cleaning solutions with addition of an aqueous slurry of aluminum hydrate. Laboratory tests proved the possibility of producing secondary cryolite with a preselected CD by changing the technological parameters of washing off of regeneration cryolite. The authors also carried out pilot tests of washing off of regeneration cryolite with hexafluoro-aluminum acid commercially produced using corrosion inhibitor