FI58078C - FAST FLOCKNINGSMEDELPREPARAT INNEHAOLLANDE POLYMER - Google Patents

Description

U.S. Patent No. 5,8078 to U35 6,188 discloses a flocculant composition which, in addition to a polymeric flocculant, contains a water-soluble adhesive.

However, wax has been used to bind the various ingredients. The finished flocculant product does not contain water, which is an essential ingredient in the present invention.

Namely, the addition of water is important when it dissolves as a generator of heat released from the fixative salt, whereby cohesive bodies are cast or compressed. . *

GB patent publication 5 ^ 8 290 also deals with solid flocculant preparations. However, they do not contain a polymer but sodium aluminate f as a flocculant. They may or may not contain a suitable salt to form a solid flocculant preparation.

According to the present invention, there is provided a solid flocculant preparation characterized in that it contains, by weight, a water-soluble fixing agent salt of 10-97% flocculant 1-35% water 2-70%,

The rate at which a solid flocculant dissolves in a liquid is determined by the relative amounts of the ingredients.

Sustained release agents preferably have ingredients in the following ranges (by weight):

Slow flocculant preparations

Generally Preferred Most preferably

Fixative salt 10-97 not less than .10 10-35

Flocculant 1-35 1-30 5-25

Water 2-70 5-70 35-70

In the case of the fastest releasing flocculant, the amount of flocculant is preferably 0.1 to 10% by weight of the amount of water sufficient to moisten the flocculant, the remainder being a water-soluble fixing agent salt.

In the case of slow-releasing flocculant preparations, the flocculant and the fixing salts are preferably first mixed together and then water is added. The mixtures self-cure to give solid products, usually within 5 minutes to 12 hours, at the same time releasing A

heat. In the case of faster flocculant releasing preparations, 1 3 58078 the flocculant and water are preferably mixed first and the fixing agent is then mixed, and the moist mixture is preferably tableted in a suitable press.

The exact way in which the ingredients of the flocculant preparation act to form a solid that decomposes in water releasing the flocculant is not clear. Studies have shown that a water-soluble fixative salt and a flocculant form a cohesive solid that behaves quite differently from the flocculant body alone. Instead of colloidal gel formation, which inhibits the continuous release of the flocculant, the flocculant is gradually and continuously released.

The flocculant preparations according to the invention may be in the form of a cylindrical body, the size and area of which can be adjusted so that the body disintegrates, releasing the flocculant for a certain time, e.g. from 8 hours to 8 days. According to a specific example, a body with a volume of 3 ° of 500 cm was fitted to a stream of water with a flow rate of 1 * 5 μl / h at a temperature of 20 ° C.

The body lasted 2k hours, during which time the amount of flocculant in the stream was 1 ppm. Flocculation can be carried out in acidic, neutral or basic liquids.

Suitable flocculants for use in the compositions of the invention include, for example, homo- and copolymers of substituted and unsubstituted acrylamide, such as polyacrylamide, partially hydrolyzed polyacrylamides and partially quaternized polyacrylamides, and other polymers containing polymerized amides, amines, amines, amines. The molecular weight of the flocculating polymer is preferably 100,000 to 30 million, most preferably 1 million to 15 million. Naturally occurring materials can also be used as a flocculant or as part of it.

The fixing salt is preferably a water-soluble salt of an inorganic or organic acid, the quality of the salt used being determined by the polymer flocculant used. Examples of suitable salts are the sodium, potassium and ammonium salts of carbonic, sulfuric, silicic, benzoic, citric, phosphoric and boric acids. For low hydrolyzed polyacrylamides, sodium carbonate is the most preferred binder, while for moderately hydrolyzed polyacrylamides, sodium tetraborate alone or in combination with carbonate is most preferred. In the case of highly hydrolyzed polyacrylamides, it is preferred to use carbonate and in the case of cationic polymers, tripolyphosphate.

1 58078

Certain embodiments of the invention are described in the following examples, in which all parts are calculated by weight.

Examples I-VIII

The products were prepared using the ingredients shown in the following table. In each case, the flocculant and the fixing salt were mixed dry together, water was added, and the product was mixed to form an aqueous slurry. This was poured into molds to make cubes. These were removed and used to flocculate the zinc hydroxide slurry in the effluent from the zinc coating plant at pH 8.5. The songs were held in a wire basket in the waste stream and were replaced with new ones at the end of each shift. The studies showed that the flocculant was released mainly at a constant rate during the shifts due to the dissolution of the bodies and satisfactory flocculation occurred continuously.

_Example Flocculant_Fixer_Water __Chemical_Part Chemical_Part Part I Anionic polyacrylic Sodium carbonate 30 1 * 5 amide, molecular weight 15 million II Highly hydrolyzed 6-sodium hydrolyzate 5 Sodium carbonate 82 polyacrylamide b2 52 polyacrylamide 50 naa IV Cationic polyacrylic- 15 Sodium tripolyphosphate- 35 50 amide, molecular weight 2 million V Anionic polyacrylate, 15 Sodium bicarbonate- 55 30 Molecular weight 10 million lines VI Non-ionic polyacrylic- 25 Sodium benzoate 35 Uo amide, molecular weight 8 million - 35 Potassium carbonate 10 55 polyacrylamide, molecular weight 5 million VIII Cationic polyacrylic 20 Sodium tetraborate 10 70 amide, molecular weight 1 '5 million j 5 58078

Example IX

Polyethylene oxide, molecular weight 1 million, (1 part) was moistened with water (2 parts) and mixed with sodium carbonate (97 parts). The resulting wet powder was compressed in a tablet press to make a body. This was fitted to the effluent stream of the scrubbing treatment in which the body dissolved, whereby the released carbonate adjusted the pH of the gaseous water and the released flocculant flocculated the finely divided material in the effluent.

Claims (6)

6 5607Θ A solid polymer-containing flocculant preparation, characterized in that it contains, based on the weight, a water-soluble fixing agent salt of 10-97% flocculant 1-35% water 2-70%. 4 Flocculant preparation according to Claim 1, characterized in that the ingredients are present in the following weight ratios: water-soluble fixing agent salt 10 to 35% flocculant 5 to 25% water 35 to 70%. A flocculant preparation according to claim 1, characterized in that the ingredients are present in the following weight ratios: the flocculant 1-10% water enough to moisten the flocculant with the remainder of the water-soluble fixing agent salt. Flocculant preparation according to one of Claims 1 to 3, characterized in that the flocculant is a polymer having a molecular weight of 1 to 30 million. Flocculant preparation according to Claim k, characterized in that the flocculant is a polymer having a molecular weight of 1 to 15 million. Flocculant preparation according to one of Claims 1 to 5, characterized in that the fixing agent is a salt of an organic or inorganic acid. Flocculant preparation according to one of Claims 1 to 6, characterized in that it is in the form of a cube or a cylinder. )