Specific features of flocculation of aqueous-salt (KCl, NaCl) clay dispersions with polyacrylamide and anionic acrylamide copolymers, including the influence exerted by the procedure of polymer dissolution in water or salt solution on the sedimentation rate and density of floccules and on the hydrodynamic properties of the polymers, are described. The use of aqueous-salt solutions of flocculants enhances the flocculating effect. The most effective flocculant for aqueous-salt clay dispersions is polyacrylamide prepared in a salt solution, which is due to higher flexibility of the polymer chain. The results obtained are of practical interest in connection with the possibility of enhancing the efficiency of the flocculation of aqueous-salt clay dispersions in dressing of potassium ores.

Rheological properties and concentration cross-overs of nonionic polyacrylamide and anionic acrylamide copolymers in saline solutions (sodium and potassium chlorides) of different concentration (0.07 and 3.4 mol/l) were investigated using the capillary viscometer method. It is shown that increasing the content of ionic groups of macromolecules reduces crossover concentration. The area of non-overlapping coils between the crossover concentration and the concentration of fluctuation mesh formation was determined for polyelectrolytes; it was shown that with increasing salt concentration this area practically disappears, i.e. the mass transfer mechanism changes near crossover concentration as in the saline solution of nonionic polyacrylamide. An effective volume of polymer macromolecules is higher in the sodium chloride solution than in the potassium chloride solution; for polyelectrolytes, it is higher than for nonionic polymers and grows with increasing the number of ionic groups of polyelectrolyte macromolecules.

It has been found that organophosphates are more efficient as inhibitors for calcium and magnesium carbonate formation and corrosion, whereas polyacrylic acid and its sulphonic modified derivatives act as stabilizers of carbonate dispersion. The binary mixture of organophosphate and polyacrylate demonstrates high efficiency of inhibiting action. The reagent mode and the complex cooling water treatment program at the Mineral Wax Plant have been developed, reducing the water consumption significantly.

Effect of polyacrylamide (co)polymers on the properties and structure of floccules formed in the course of phase separation of a salt dispersion of clay was studied. It was shown that, with a binary system of unlike-charged copolymers, a sediment with high density and water-yielding capacity is formed, which is necessary for the effective phase separation. The subsequent squeezing of the flocculated sediment to remove water leads to a local increase in the concentration of polymers in the solid phase, which raises the plastic strength of the sediment and improves the granulation conditions.

It has been shown that both gravimetric method and electrochemical methods can be used to evaluate the effect of additives on the rate of corrosion. The results of determining the corrosion rate by the electrochemical method under dynamic conditions are in good agreement with the results of field tests.

The effect of polyacrylic acid and polyethylene glycol on the crystallization of calcium carbonates in the presence of magnesium ions was studied. It was found that the presence of magnesium ions in solution and the treatment temperature (80°C) influence the formation of the final products of calcium carbonate crystallization. In binary mixtures, low-molecular-weight polyacrylic acid and polyethylene glycol affect synergistically, and such mixtures can be used for selectively influencing the formation of calcium carbonate polymorphs.

Изучено влияние полиакриловой кислоты и полиэтиленгликоля на процесс кристаллизации карбонатов кальция в присутствии ионов магния. Установлено, что присутствие в растворе иона магния и температура обработки (80°C) оказывают влияние на образование конечных продуктов кристаллизации карбоната кальция. Бинарные композиции на основе низкомолекулярной полиакриловой кислоты и полиэтиленгликоля проявляют синергизм и могут использоваться для селективного воздействия на образование полиморфных модификаций карбоната кальция.

Исследована последовательная адсорбция противоположно заряженных полиэлектролитов – катионных и анионных сополимеров акриламида – на поверхности частиц твердой фазы из растворов с высокой ионной силой. Рассчитаны константы в уравнении Фрейндлиха для адсорбции различного типа полимеров. Определена взаимосвязь между величинами адсорбции полимеров и их флокулирующей активностью в отношении глинисто-солевых суспензий. Последовательная адсорбция противоположно заряженных полиэлектролитов оказывает сильное влияние на флокуляцию в связи с образованием полиэлектролитных комплексов на поверхности частиц глины. Предложен механизм образования комплекса.

Successive adsorption of oppositely charged polyelectrolytes, namely, cationic and anionic acrylamide copolymers, on a solid phase surface from solutions with high ionic strength is investigated. The constants of the Freundlich equation are calculated for the adsorption of different polymers. The interrelation between the adsorption values of polymers and their flocculation activity with respect to clay-salt suspensions is determined. The successive adsorption of oppositely charged polyelectrolytes strongly affects the flocculation due to the formation of polyelectrolyte complexes on the surface of clay particles. The mechanism for complexation is proposed.

Изучены особенности формирования полиэлектролитных комплексов на основе катионных и анионных сополимеров акриламида с различной плотностью заряда макромолекул на поверхности частиц каолина в высококонцентрированном солевом растворе. Взаимодействие сополимеров с поверхностью частиц глины и между собой исследовано электрокинетическим методом и методом ИК-спектроскопии. Изучены реологические свойства суспензий каолина в солевом растворе в присутствии полиэлектролитов. Проведена оценка флокулирующей способности полиэлектролитов и их бинарных смесей по отношению к глинисто-солевым дисперсиям. Обсуждается механизм образования полиэлектролитного комплекса на поверхности частиц глины. Показано, что образование комплекса на основе противоположно заряженных полиэлектролитов на поверхности частиц глины приводит к усилению флокуляции глинисто-солевых дисперсий.

Peculiarities of the formation of polyelectrolyte complexes based on cationic and anionic copolymers of acrylamide having different macromolecule charge densities on the surfaces of kaolin particles in highly concentrated salt solution are investigated. The interactions of the copolymers with the clay particle surface and with each other are studied by electrokinetic and IR spectroscopy methods. The rheological properties of kaolin suspensions are investigated in a salt solution in the presence of the polyelectrolytes. The flocculation ability of the polyelectrolytes and their binary mixtures with respect to clay-salt dispersion is estimated. The mechanism for the formation of polyelectrolyte complexes on the surface of clay particles is discussed. It is shown that the complexation of oppositely charged polyelectrolytes on the surfaces of clay particles intensifies the flocculation of clay-salt dispersions.

The wetting of the potassium chloride surface by water-soluble polymers and polymer-surfactant complexes, which is highly important for granulation of potassium chloride, was studied. The efficiency of the wetting process was analyzed using a polymer-surfactant combination in comparison with individual polymers.