Concentration Influence of the Water Soluble Polyelectrolyte Functional Composition on the Clay Suspension Active Stability

Koblanova O., Abzalova D., Asilbekova G., Abramova G.

International Kazakh-Turkish University named after H.A. Yassavi

Shymkent Institute

According to the solution theory the equal behaviour of the surfactants and poly electrolytes is determined by their ability to form real solutions at low concentrations and colloid solutions at high concentrations; the polymer is in the molecular type, and this provides for the formation of the adsorption layer /1/.

Surfactants and VRP molecules are charged positively or negatively according to the nature of the functional ion gen groups; it gives the specificity to their adsorption on the disperse phase particles /2/.

Influence of the VRP concentration and functional composition on the aggregate stability of the suspension hydro mica-montmorillonit clays was studied with the help of: poly functional electrolytes SUMAK, based on the synthesis with the humine acids and metacril acids, SUMMA based on the synthesis with the humine acids and metilmetakrilamid, SUOVN based on the synthesis with the humine acids and nitron fibre production wastes. For comparison we have studied the influence of poly functional hydrolyzed nitron fibre production wastes /K-9/ which are widely used in drilling works. They contain carboxilate, amid and metaxile groups, poly metacril acid (PMA), and carbon alkali reagent (CAR), produced from the new Lenger deposit brown carbon /3/.

Some decreasing of water output and 24-hourly sediment may be stated in the suspension with increasing PMA concentration from 0, 02 to 0, 1%. This may be explained by the adsorption of some polymer molecules and formation additional hydrophobic segments in the surface of the clay particles. They are in charge of the contacts, increasing the system stability. Absolute surface hydrophobization and suspension aggregation are the result of the further increasing of PMA concentration.

Testing of the hydro-mica-montmorillonit clays by natrium humat /0, 5% / manifested their greater values of water output, clay crust thickness and 24-hourly sediment in the suspension of Darbasi bentonite. This testifies to the structure weak tixotrope strengthening. The increasing of natrium humate content from 0, 5 to 2, 0 % water output and 24-hourly sediment are decreased, it speaks to the fact that clay suspensions coagulation structures increase their strength /2/.

Thus, while processing of the hydro-mica-montmorillonit clays by sodium humat /0, 5% / the excess of alkali, presenting in the reagent, provokes the clay particles partial peptization as a result of ion exchange, the humats are in charge of formation of the structural-mechanical barrier, which prevents the compact aggregation. If the concentration of sodium humate in the clay - water system is increased to 2, 0% the clay dispersion aggregates start to decompose with the following stabilization. It is caused by the stability structural mechanical factor because the sodium humate molecules are fixed on the active centres of the clay minerals. 2, 0% additive provides for the absolutely complete blocking of the disperse clay by the adsorbed macro molecules and the system stabilization.

If the acryl humate co-polymers additives are insufficient (SUMAK, SUMMA, and SUOVN) we have marked the failure of the coagula structure formation; it is proved by the system stability change characteristics. Thus, adding the 0, 1% co-polymer into the clay suspension increases the suspension water output, 24-hourly sediment, and clay crust thickness. The decrease of system structural units might be stated because the co-polymer combines the clay particles and new type contacts are formed, mainly due to the surface hydrofobization. So, we can make a conclusion that, small additives of co-polymers, just as the other poly functional polymers hinder the development of space coagula systems. During the polymer adsorption phase contacts along the surface hydrophobe segments are developed instead of point-wise contacts on the surface of clay particles, it leads to the formation of the contact aggregates, in favour of the suspension segregation.

The further increasing of the co-polymer concentration /from 0, 1 to 0, 5%/ provides for the increasing of the clay suspension aggregate stability. This process is accompanied by the formation and development of tixotrope - coagula structures. If the adding of co-polymer is 0, 5% and more, we may state the continuation of water output and 24-hourly sediment decreasing. This fact may be explained by the fact that the clay particles surface nature has been influenced by the polymer activity. Poly electrolytes form hydrofoil shell from the co-polymer macro molecules, adsorbing on the surface of the clay particles; this shell is the powerful barrier for the point-wise contact aggregation, and for the aggregation of the outer surfaces of these hydrofoil shells. So, this provides for the increasing of the coinciding space clay and polymer disperses thermodynamic stability.

A tixotrop characteristic is the main feature of the suspension stability quality. Figure 1 shows the dependence of tixotrop factor F_T from the concentration of poly electrolyte studied at the shift stress τ=7, 5 H/m² , which is changed simbatly with the plastic strength plastic dependence curve P_M=f (c). Tixotrop factor F_T increasing in the first segment testifies the slight reduction of the destroyed structure. The polymer adsorption layers in the second segment reveal the stabilizing action; they possess the optimal thickness, providing the fragments and frame structural units mobility. This also favours for the reduction its parameters almost to the starting ones, though the tixotrop factor is decreasing. If we start with the co- polymer concentration SUMMA 0, 1% in the clay-water-polymer system the tixotrop factor is sharply increased, i.e. the structure reduction degree is decreased /the third segment/. This fact may be explained. The destroyed structure fragments orientation is hindered because of the great co-polymer concentration, which possesses the viscosity itself and is capable of forming the tixotrop structure.

Fig.1 SUMA co polymer influence on the plastic strength (1), total power (2) and tixotrop factor (3) of the hydro-mica-montmorillonit clays suspension.

This, SUMMA co -polymer in the concentration limits 0, 1-0, 5% provides the stabilizing influence on the hydro-mica-montmorillonit clays suspension.

Consequently, we may obtain stable, suspensions, possessing tixotrop –coagula structures with the help of acryl-humat co-polymers (SUMAK, SUMMA, SYOVN). The suspensions meet the requirements of stability /K_Y/. 0, 5% additive of the acryl-humat co polymers is considered to be optimal. The results of the analysis show that Darbasi deposit suspensions of hydro-mica-montmorillonit clays, processed by the acryl humat reagents- stabilizers in the optimal concentrations are characterized by low water-output, 24-hourly sediment and stability values. Structural-mechanical characteristics correspond to the filtration properties.

The poly electrolytes under study may be enumerated as follows concerning the stabilizing influence on the clay suspension:

SUMMA>SUOVN>K-9>SUMAK>PMAK

Reference:

1.Koblanova O.N. Investigation of the dilution action mechanism on the cement-raw slime. – KazIRI. – 1989. - ¹ 2912-89. – P.5.

2. Koblanova O.N., Abishev M.Zh., Komekbayeva B.A., Djakipbekova N.O. Study of the aggregate stability and structural formation of the mineral dispersions with the ampholite acryl poly electrolytes //Proc. Of the Intern. research-technical and educ.-method. Conference ‘Actual problems of science, technology, production and education’. – Shymkent, 1993. – Part1. – P. 23-35.

3. Koblanova O.N., Satayev I.K. Optimization of the water soluble poly electrolyte SUOVN stabilizing characteristics. – KazGosIRI. - ¹ 5046-Ka 94. // Research papers. – Almaty, 1994. – issue 2. – P.70.