Selective Flocculation Study of Hematite in HematiteQuartz-Kaolinite System in Presence of Ca2+, Mg2+ and Fe3+ Ions. Part1: Optimization of Ligand

Separation of ultrafine hematite from quartz and kaolinite gangue minerals using selective flocculation technique is markedly affected by the state of inter mineral interaction which is governed by type and content of polyvalent metal ions. Because of the presence of polyvalent metal ions hetracoagulation of gangue minerals is widely acknowledged, thus selective flocculation of ultrafine hematite from associated gangue minerals is challenging task when their concentration is above 10 ppm. This study has shown that state of strong interaction of gangue minerals with hematite due to presence of 15 ppm Ca2+, 3 ppm Mg2+ and 3 ppm Fe3+ ions can be weakened by addition of optimal dose of Sodium Hexametaphosphate (SHMP) ligand. The optimization of ligand dose is achieved through analysis of Zeta Potential (ZP) as a function of slurry pH. It is noted that 50 ppm of SHMP is sufficient to restore the ZP of hematite, where selective dispersion of the slurry constituents are possible. Our results further showed that conventional strategy of obtaining minimum difference of ±30 mV in the ZP of hematite and gangue minerals quartz and kaolinite would not work especially in the presence of 15 ppm Ca2+, 3 ppm Mg2+ and 3 ppm Fe3+ ions. Attempts to achieve the minimum threshold difference in the ZP of the minerals will cause over dispersion.

INVESTIGATION OF THE PROCESS OF CHEMICAL CROSSLINKING OF NA-CMC POLYVALENT METAL IONS

This article is devoted to the study of the Na-CMC structuring process under various conditions: structuring with polyvalent metal ions, structuring with polyvalent metal ions in the presence of polybasic acids. Structuring in a Na-CMC solution was investigated by adding polyvalent metal ions to it at various ratios Me+p / COO-, pH, which allowed us to characterize the structuring process as a reaction of macromolecules with low molecular weight compounds.It was found that the probability of intermacromolecular crosslinking, responsible for gelation, increases with an increase in the initial concentration of Na-CMC solution and with the additional presence of polybasic acids. When salts of polyvalent metals interact with solutions of polybasic acids in the presence of a 2N NaOH solution, their complex salts are formed.Titration calculations and IR spectra of dried salts confirmed the conclusion made about the formation of salts of structure I, II, III, IV. Crosslinking of Na-CMC has been shown to occur via compounds of the M2+ (3+) - OOS-R-type. It has been established that strong, transparent jellies are formed by trivalent metal ions, divalent metal ions also form brittle, cloudy jellies that stratify during a day.A suggestion has been made that the main reaction during gelation of the Na-CMC solution is the interaction of -COOH groups along the chain of the Na-CMC macromolecule with the Al+3 salt and citric acid of structure III. The role of citric acid is that it is a transverse bridge in the binding of Na-CMC macromolecules. During the process of chemical crosslinking, the system turns from a fluid state into a non-fluid one, and the dynamic viscosity of the system increases from 3.548 Pa·s to 1585 Pa·s.

Extended short-range order determines the overall structure of liquid gallium

Polyvalent metal melts (gallium, tin, bismuth, etc.) have microscopic structural features, which are detected by neutron and X-ray diffraction and which are absent in simple liquids.

Features of the Sorption Process of Polyvalent Metal Cations in Soils

The issue of migration and accumulation of harmful and toxic compounds in soils is considered. Particular attention is paid to the study of the rate of ion-exchange process of cations of copper, iron, zinc, aluminum on humic acids, since these elements constitute a significant mass of harmful emissions from industrial enterprises in the form of drainage effluents to be cleaned. The results of studies of mass transfer processes in soils for various compounds are presented. An approach is proposed based on the calculation of the average dynamic value of the charge of a polyvalent metal cation extinguished when interacting with a specific sorbent, which allows a predictive estimate of the migration and accumulation of this cation within the spill of its salt solution on the soil.