The adsorption of the different ions and molecules in a solution depends on the electrical charge of the surface of the minerals undergoing flotation. The hydrophobicity and float, ability of minerals are governed by the adsorbed ions and molecules.From a study of the capacity of a double electric layer in the presence of adsorbed molecules, A. N. Frumkin et al. [1,2] derived a theory explaining the influence of an electrode's electrochemical potential on the adsorption of uncharged molecules.According to these authors, the capacity of a double layer in the field of adsorption is greatly reduced because between the layer's plates an interlayer of a substance is introduced, having a lower dielectric constant than water. A capacitor's electric field resists introduction of a body between the capacitor's plates if the dielectric constant of this body is lower than that of the medium filling the capacitor. The double layer's electric field therefore opposes adsorption of molecules reducing the layer's capacity, but assists that of water molecules. The adsorption of uncharged organic molecules is greater on surfaces with smaller charges, irrespective of the sign of the charge.Wetting with water is poorest at potentials closest to the zero charge, and increases sharply with polarization of the surface.To study the changes in the overall electrochemical potential, a limonite electrode with L = 40 mm and d = 5 mm was turned on a grinding wheel. One end of the electrode was fixed in a holder consisting of a special Plexiglas tube. Contact between the electrode and the current conductor was obtained by filling the tube with mercury.The change in E-the potential jump with changing solution pH-was measured as follows. The electrode was thoroughly cleaned on the grinding wheel in an aqueous suspension of quartz, and washed in distilled water; adhering particles of quartz were removed with filter paper, and it was then placed in a beaker with distilled water. It was placed in the agitation compartment of a flotation machine and treated with an aqueous emulsion of kerosene (500 mg/liter) for 5 min at a given pH. Without removing it from the flotation machine, it was transferred to a beaker to determine E-the potential with respect to a calomel comparison electrode.The solution pH was changed by means of H2SO 4 and NaOH. It will be seen from the change in limonite potential at various pH in an aqueous emulsion of kerosene (see figure) that the surface of limonite treated with such an emulsion has a negative charge. With increasing solution pH the negative potential of the surfaces increases owing to adsorption of the excess free hydroxyl (OH-) ions.H + and OH-ions have a very great influence on the state of the double electric layer of limonite, and, therefore, on its reaction with nonpolar reagents (hydrocarbons).The figure plots the floatability of limonite (size class 0.0'/4 mm) by kerosene (500 mg/liter) with addition of frothing agent (pine oil, 50 mg/liter) in an NIGRIzoloto flotation machine (v = 50cm 3 , n = 2000 rev/min...

Introduction:We present a case of a 40-year-old woman with IVF gemellar pregnancy in the 28th week of gestation, with primary hyperparathyroidism which complicated the course of pregnancy causing acute pancreatitis and AKI, who was treated with CRRT and succesfully overcame a hypercalcemic crisis. Methods:Case report: On admission to the Obstetrics and gynecology clinic patient was somnolent, hypertensive, tachicardic, oliguric, respiratory stable with pretibial oedema. Laboratory data showed raised inflammatory markers, anemia, elevated serum amylases, urea, creatinine and hypokalemia. Abdominal ultrasound revealed an enlarged, voluminous pancreas, whereas chest radiograph showed a large left sided pleural effusion. An inital diagnosis of severe preeclampsia was determined, with suspected acute pancreatitis. Emergent cesarean delivery was performed. In the post partum period she was treated with isotonic saline infusions, antibiotic therapy (cephalosporins, carbapenems), antihypertensive drugs, anticonvulsants, antiedematous therapy with preventive doses of heparin. After two days she was transfered to the Intensive Care Unit. She was dyspnoic with compensated respiratory acidosis. Additional laboratory findings indicated high levels of serum lipases and severe hypercalcemia (total calcium: 3,99mmol/l, ionized calcium 2,47mmol/l, hyperphosphatemia 0,45mmol/l, high levels of parathyroid hormone 834pg/ml) and hypokalemia. CT of the chest and abdomen, revealed acute pancreatitis, bilateral pleural effusions and signs of AKI. Endocranial MR showed signs of brain edema. US of the thyroid and parathyroid gland identified a cystic formation with clear borders and intranodular vascularisation in the parenchyma of the lower left lobe, size 9x13x26mm, resembling an enlarged parathyreoid gland. Other causes of hypercalcemia were excluded. Results: Previous therapy was continued with the addition of hydration (rate of 200ml/h), proton -pump inhibitors, corticosteroids, bolus doses of furosemide and byphosphonates (calcitonin was unavailable). Two combined pre-dilution procedures were performed using heparin anticoagulation and normal calcium levels of 1,5mmol/l in the dialysate. Initially CVVHDF was started (Multifiltrate Kit 8 CVVHF 1000, surface 1,8m 2 ; flow dialysate 200-300ml/h; blood flow 180-100ml/h; dialytic fluid/substitute ratio was 1:1) and further changed to CVVH with continuous potassium substitution. After the first CRRT procedure, a decrease in calcium levels was noted, with tendency for further reduction, resulting in desired (total calcium 2,23mmol/l, ionized calcium levels 1.26mmol/l) and gradual normalisation of other laboratory findings. The patients state of consciousness improved, diuresis was established and complete hemodynamic stability was reached, after which, on the 12th day of treatment, she was transfered to the Clinic of endocrionology for further treatment. Conclusions: Combining CRRT modality with heparin anticoagulation and careful monitoring of electrolyte levels can contribute to adequate...

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electrode, leading to accumulation in the solution of polyvalent ions of the alloy components of the steel, particularly Cr (VI) ions.Phosphoric acid does not undergo electrolytic oxidation under these conditions. 1. 2. 3. 4. LITERATURE CITED R. Sh Shafeev, V. A. Chanturiya, R. I. Sturua, V. D. Lunin, V. P. Bezrodnykh, and N. V. Rubtsov, The Use of Electrochemical Methods in Flotation [in Russian], Tsvetmetinformatsiya, Moscow (1971). V. D. Lunin, V. P. Yakushkin, M. I. Baskakova, Sh. A. Makhmutov, and Zh. A. Abdraimov, "Influence of preliminary electrochemical oxidation of phosphoric acid on the efficiency of its effect during flotation of phosphate-carbonate ores," in: Ways for Developing the Karatau Phosphorite-BeaHng Basin [in Russian], Kazakhstan, A1ma-Ata (1972). V. D. Lunin and V. A. Chanturiya, "Theoretical principles of intensification of the effect of phosphoric acid in flotation of phosphorltes by its prellminary electrochemical oxidation," in: Physicochemical Methods for Increasing the Efficiency of Processing of Mineral Crude [in Russian], O. Yu. Shmidt Institute of Physics of the Earth, Moscow (1973). V. D. Lunin, "Theoretical premises for selecting anode materials during electrochemical oxidation of the phosphoric acid solution used in flotation separation of phosphorite, dolomite, and calcite," in: Problems of the Working and Beneficiation of Minerals [in Russian], O. Yu. Shmidt Institute of Physics of the Earth, Moscow (1974). ELECTRODE POTENTIALS AND FLOATABILITY MINERALS DURING ELECTRODEPOSITION I. V. Popov and V. I. Rostovtsev OF SULFIDEIn the beneflciation of complex ores, the valuable minerals are often subjected to bulk flotation followed by selection of the bulk concentrate. In this case the adsorptionlayers of the collector reagents are broken.A review of known methods for removing an excess of collector from bulk concentrates is given byKonev and Debrivnaya [1]. They give the followingtmethods for collector desorption: 1) thickening of the bulk concentrate; 2) filtration of the concentrate; 3) successive use of thickening and filtration; 4) absorption of the reagents by active carbon; 5) treatment of the concentrate in autoclaves at a high tempera~zre; 6) roasting of the concentrate.An analysis of these methods reveals that none of them sufficiently meets the requirements imposed on the procedure for separating bulk concentrates.

Особенности морфологии и состава хромшпинелидов имеют важное значение для решения ряда геологических задач: от реконструкции состава субстрата родоначальных расплавов и физико-химических условий их эволюции, установления приуроченности магматических комплексов к геодинамическим обстановкам до оценки минерагенического потенциала ультрабазитовых массивов.Цель работы– изучение акцессорных хромшпинелидов из серпентинитов тектонического меланжа на северном флангеДаховского кристаллического выступа, входящего в состав тектоническойзоны Передового хребта Большого Кавказа, выделение сохранивших исходный состав хромшпинелидов и установление условий их образования. Методы исследования: электронно-зондовый микроанализ и электронная микроскопия, статистический анализ результатов измерений. Результаты работы.Выделеныхромшпинелиды с вторичными изменениями и сохранившие исходный состав. В ходе сопровождавшей обдукциюсерпентинизацииультрабазитов (с образованием лизардит-хризотиловой ассоциации) хромшпинелиды частично трансформировались из субферрихромитов в хромиты, что сопровождалось перераспределением алюминия и магния (и обогащением внутренних зон хромом) в значительной части зерен и это в целом типично для условий низкотемпературного метаморфизма. Эти изменения выражены в образовании внешних обогащенных алюминием зон (Al2O3 более 10 вес.%) и его выносом из внутренних частей (где содержание Al2O3 неравномерное – от вариаций в пределах зерна в диапазоне 4.5-9 вес.% до менее 2% вес.%в сильно измененных разностях). Анализ корреляционныхсвязей между элементами и переход в Cr-обогащенную шпинельуказывают на преобладание двухвалентной формы железа во флюидах, что типично для восстановительных условий и высокого соотношения флюид/порода. Последующие изменения проявлены в образовании магнетитовых оторочек в окислительных условиях при интенсивной фильтрации в серпентинитах высокотемпературных гидротермальных растворов. Этот завершающий этап трансформации хромшпинелидов следует связывать с концом этапа герцинской коллизии, когда фрагменты апогипербазитовых тел, оторванные от офиолитового меланжа, были причленены к краю Даховского блока кристаллиникума, интенсивно дислоцированы и прорваны малыми интрузиями завершающей фазы гранитоидного магматизма. Интенсивное дробление и циркуляция растворов проявлены в формировании нескольких генераций магнетита, образующих тонкие пересекающиеся прожилки в серпентинитах. Первичный состав хромшпинелидов(соответствующий субферрохромитам с Cr# 0.80-0.81) указывает на их близость к типу офиолитовсупра- или надсубдукционных зон (SSZ), в частности к гарцбургитовымофиолитам фронтальных частей островных дуг, ультрабазиты которых образуются в условиях плавления деплитированойгарцбургитовой мантии Features of the morphology and composition of chrome spinels are important for solving a number of geological problems: from reconstructing the composition of the substrate of the initial melts and the physicochemical conditions of their evolution, establishing the confinement of magmatic complexes to geodynamic settings, and assessing the mineralogenic potential of ultrabasite massifs. Aim.Studying of accessory chrome spinels from serpentinites of tectonic melange on the northern flank of the Dakhovsky crystalline protrusion, which is part of the tectonic zone of the Front range of the Greater Caucasus, identify the chromium spinels that retained their original composition and determination the conditions of their formation.Methods.Electron probe microanalysis and electron microscopy, statistical analysis of measurement results.Results.Groups of grains with secondary changes and groups that retained the original composition have been distinguished. During the serpentinization of ultrabasites accompanying the obduction (with the formation of lysardite-chrysotile association), chrome spinels partially transformed from subferrichromites to chromites, it was accompanied by a redistribution of aluminum and magnesium (and enrichment of the inner zones with chromium) in a significant part of the grains and it is generally typical for conditions of low-temperature metamorphism. These changes are typical in the formation of external zones enriched with aluminum (Al2O3 more than 9 wt.%) and its removal from the internal parts (where the Al2O3content is uneven - from variations within the grain in the range of 4.5-9 wt.% to less than 2% wt.% In greatly modified differences). The transition to Cr-enriched spinel and an analysis of the correlation between the elements indicate the predominance of the divalent form of iron in the fluids, which is typical for reducing conditions and a high fluid / rock ratio. Subsequent changes can be seen in the formation of magnetite rims under oxidizing conditions during intensive filtration of high-temperature hydrothermal solutions in serpentinites. This final stage of the transformation of chrome spinels should be associated with the end of the Hercynian collision stage, when fragments of apogiperbasite bodies torn from the ophiolitemelange were attached to the edge of the Dakhov block of the crystallinum, intensively deployed and broken through by small intrusions of the final phase of granitoidmagmatism. Intensive crushing and circulation of solutions can be seen in the formation of several generations of magnetite, forming thin intersecting streaks in serpentinite. The primary composition of chrome spinels (corresponding to subferrochromites, Cr# 0.80-0.81) indicates their proximity to the type of ophiolites of supra- or suprasubduction zones (SSZ), in particular, to harzburgiteophiolites of the frontal parts of island arcs, ultrabasites of which are formed under conditions of melting of the deplicatedharzburgite mantle