FR2555980A1 - Chemical products for water treatment - Google Patents

Abstract

Chemical products for water treatment, either of water for household or industrial use, or of aqueous wastes. The products according to the invention are characterised by the incorporation of an acidic solution of a silicate in an aqueous solution of hydrolysable metal salts. The metal salts employed in these products belong to the divalent or trivalent classes of the base metal. The ratio of the constituents may be variable, the acidic silicate solution may be incorporated in a single type of metal salts or in a combination of such salts. The field of application of these products extends from the treatment of potable water and that for industrial use to the purification of aqueous wastes which are the most difficult ones to treat, for example the breaking of metal machining fluids.

Description

The present invention relates to chemicals for the treatment of water, either water for domestic or industrial use, or waste water,
Until now, there is no chemical which would be applicable both to the treatment of most waste water in the form of aqueous dispersions, as well as water for domestic or industrial use.

In different fields, it is often necessary to use different chemicals, for example: ferrous or ferric chloride for the removal of organic dyes or humic substances from water intended for human consumption; with alllminium sulfate to precipitate phosphates from a stream of domestic wastewater; with aluminum chloride to coagulate clay materials suspended in quarry wash water; with sulfuric acid and hydrochloric acid, with calcium or magnesium chlorides with products based on bentonite or on the basis of organic substances for the breaking of a limited spectrum of working fluids of mEX rates, for the elimination latex residue, etc. The need for a wide range of chemicals, often on the same site, for water treatment results in high costs3 and a complicated supply system.

 Chemicals in the form of powders are often used for particular applications, for example for breaking metal working fluids. these have many drawbacks. In particular, the salts contained in these powders must not have hygroscopic properties which would lead to a premature reaction between the various constituents of the powders, and would result in a significant loss of reactivity. The powders cannot be used, in the processes operating continuously, in an industrially profitable manner; they raise the problem of dust formation with, in a large number of cases, the danger of silicosis for the personnel, and their use involves installations of a large size because of their low solubility in the reaction mass.

 The invention aims to overcome the drawbacks of the prior art, and to provide chemicals for the applications indicated above, with methods relating to their production.

 The principle of the present invention is based on the incorporation of an acidic solution of a silicate in an aqueous solution of hydrophilic metal salts. The solution of the silicate can be obtained by the action of hydrochloric, sulfuric, etc. acids. . on sodium silicate; it can also be obtained by the action of these same acids on an alumina silicate (bentonites, kaolin, talc, etc.), either in cold or in heat. The water-soluble metal salts can belong to the bivalent and / or trivalent classes of base metals, for example chlorides and sulfates of iron, aluminum, magnesium, calcium chloride.

 The characteristics and advantages of the present invention will be better understood on reading of examples of preparation of said products and examples of their uses which will follow.

Example 1:
Preparation of a product according to the invention from a solution
sodium silicate acid and an aqueous solution of chloride c
minimum:
Formulation: 1% mass sodium silicate acid solution
aqueous aluminum chloride solution, d = 1.30 99% mass
Manufacturing process: dissolve 1 gram of sodium silicate in 1 kilo-
gram of 35% hydrochloric acid; add this solution to
99 kilograms of aluminum chloride, d = 1.30; shake up
obtaining a homogeneous mixture.

Example 25
Preparation of a product according to the invention for spreading bentonite from
chlorhadricue acid and an aqueous solution of chloral
minium: Formllation: 2% mass bentonite acid extract
98% mass aluminum chloride aqueous solution
Manufacturing process: heat treatment 1 kilogram of bentonite per ri kilo
gram of 35% hydrochloric acid for 24 hours; to separate
mix and allow the acid extract to cool; add this ex
dash (2 kilograms) to 98 kilograms of aluminum chloride,
d = 1.30; shake until a homogeneous mixture is obtained.

Example 3:
Preparation of a product according to the invention from a solution
sodium silicate acid and aqueous chloride solution
ferric:
Formulation: 1% mass sodium silicate acid solution
hydrochloric acid 35% 1% mass
saturated aqueous solution of ferric chloride 98% mass
Manufacturing process: slowly add hydrochloric acid to the chloride
ferric and vigorously stir the reaction mass; add to
this mixes the acidic sodium silicate solution; shake up
obtaining a homogeneous mixture.

Examples i to 3 represent only a few possibilities for mixing between the substances mentioned above; other combinations are possible and feasible. The common feature of all these products is the incorporation of an acidic silicate solution which leads to aqueous dispersions, to destabilization and separation effects hitherto unknown.

Example A:
Removal of humic substances from drinking water:
Add to the water to be treated the quantity of product necessary to cause coagulation of humic substances; shake gently for 5 minutes; separate the phases by filtration methods, flotation settling, as appropriate.

Example 5:
Removal of dyes from dyeing waste water:
Add to the waste water to be treated the quantity of product necessary to cause the coagulation of the residual dyes; shake gently for 5 minutes; add a neutralizing agent if the waste water is acidic; separate the phases by filtration, decantation, flotation methods, as appropriate.

Example 6:
Elimination of turbidity from industrial # usa water:
Add to the water to be treated the quantity of product necessary to cause coagulation of the annoying substances; shake gently laying for 5 minutes; separate the phases by filtration, decantation, flotation methods, as appropriate.

Example 7:
Breakage of a rectification emulsion based on synthetic oils
with ultra-fine dispersion in the continuous phase:
Disperse finely in the emission to break the amount of product necessary to cause breaking; shake gently for 1 minute; add, if necessary, a suitable polyelectrolyte to assist the flocculation; separate the phases by filtration, decantation, flotation methods, as appropriate.

 In general, the chemicals according to the invention have proved to be very effective in drinking water treatment plants, in the treatment of waste water in the mechanical, food, meteorological industries; in the paint, paper and textile industries, this is to say, wherever harmful and / or annoying substances are to be removed from water for domestic or industrial use, or from waste water.

Claims (4)

 1. Chemicals for water treatment, either water for domestic or industrial use or waste water, characterized in that these products contain an acid solution of a silicate in a body of hydrolysable metallic Bels.  2. Chemicals according to claim lo, characterized in that the acid solution of a silicate can be obtained from sodium silicate under the action of mineral acids; or from aluminum silicates also under the action of mineral acids, by cold or hot reaction.  3. Chemicals according to claim 1., characterized in that the acid silicate solution will be incorporated into the aqueous solutions of the hydrolysable metal salts belonging to the bivalent and / or tri-valent classes of the base metals.  4. Chemical products according to claim 1., characterized in that the ratio of their constituents can vary, and that the acid silicate solution can be incorporated in a single type of metal salts or in a combination of such salts.