SU923963A1 - Method for preventing formation of mineral salt deposits - Google Patents

Description

The invention relates to the processing of water and aqueous solutions and can be used to prevent the formation of deposits of mineral salts in the water supply, water treatment and production of mineral fertilizers.

A known method of preventing deposits from aqueous solutions, by processing in a constant electric field ¹ , which is created by two insoluble electrodes C1] "

The disadvantage of this method is the low efficiency of water treatment.

Closest to the proposed technical essence is the C2] method of preventing deposits in water supply systems, based on dosing in aqueous solutions of organo2 aminomethylene phosphonates of the general formula ¹ [-CH ₂ -CH ^ -Ν] _and I

where the degree of polymerization is from 5 to 16

The disadvantage of this method is the low efficiency of the treatment of acidic waters and aqueous solutions having a pH <. 5. This is due to the fact that organoaminomethylene phosphonates ₅ are organic acids or salts, the ionization of which is suppressed in an acidic medium. Since the anion is the active part of the reagent molecules, this leads to a decrease in the effectiveness of the reagents to prevent mineral deposits.

The purpose of the invention is to increase the degree of prevention of deposits from acidic aqueous solutions.

s 923963

The goal is achieved by that. that the aqueous solution is treated in an electric field with an intensity below the voltage of the electric decomposition of the solution.

Preferably, the electric field is 0.25-0.75 V.

The nucleation of crystallization nuclei occurs on the surface of previously formed nuclei. The anion of organoaminomethylene phosphate is adsorbed on the surface of the embryo and weakens its force field.

In an acidic medium, the ionization of organoaminomethylene phosphonate decreases and the adsorption of the anion on the surface of the crystallization nucleus decreases.

In the presence of an electric field, the efficiency of organoaminomethylene phosphonate increases due to the discharge of crystallization nuclei, which passes on the anode, which helps to reduce the formation of salt deposits.

Example 1. A supersaturated solution of calcium sulfate, obtained by 5 mixing equivalent amounts of calcium chloride (CaCC ^) and sodium sulfate (Per _g 50d ·), adjusted to pH 1 with hydrochloric acid and treated with 0.1% organo-amine solution 1 ° Lenphosphonate, Insoluble electrodes are placed in the Ca5O ^ solution, to which a voltage of 0.50 V is applied, thermostatically at 70 ° C. The duration of the induction period 15 of crystallization of Ca50c is determined turbidimetrically on a nephelometer-colorimeter. The induction period is 90 minutes.

The table provides comparative data on the prevention of deposits by the proposed and known methods.

Characterization of oversaturated Ca50 ^ - solutions The method of processing supersaturated solutions of calcium sulfate Duration of induction periods, min. Concentration solution Ca50 <= 8.5 g / l, pH = 1 Organoaminomethylene Phosphonate (3 mg / L) 45 Joint processing organoaminomethylene phosphonate (3 mg / l) and electric field: and = 0.25 V 55 and = 0.50 V 90 and = 0.75 in 75 Concentration solution Ca50c = 4 g / l, pH = 3 Organoaminomethylene Phosphonate (3 mg / L) Joint processing organoaminomethylene phosphonate (3 mg / l) and electric field: fifty 11 = 0.25 V ⁶⁰ and = 0.50 V 95 and = 0.75 V 55

From the data presented in the table, it follows that the most effective effect on the crystallization of calcium sulfate is achieved by the method of simultaneous treatment of supersaturated acid solutions with organo-aminomethylene phosphonate and an electric field with a voltage below the voltage of the electrolytic decomposition of the head. The duration of the induction period in this case increases by 22.5 times compared to with a known method.

Claims (2)

Claim 1. A method of preventing the formation of deposits of mineral salts, including the treatment of aqueous solutions with organoaminomethylene phosphonate, characterized in that, in order to increase the degree of prevention of deposits from acidic aqueous solutions, the aqueous solution is further subjected to treatment in an electric field with a voltage lower than the voltage of the electrolytic decomposition of the solution. 2. The method of pop. 1, it is distinguished by the fact that the aqueous solution No. ^{5 is} subjected to treatment in an electric field with a strength of 0.25-0.75 V.