Hoechst Aktiengesellschaft

Clariant Corporation

Other

Alexander Tapper

Gunther R Schimmel

Josef Holz

Michael Kotzian

Volker Thewes

Hans-Peter Rieck

Herbert Panter

Gerd Wingefeld

Harald Bauer

Renate Adrian

Gerhard Noltner

Horst Buhl

Guenther Schimmel

Jan Wilkens

Knut Bauer

The invention relates to a sparingly soluble alkali metal silicate which comprises alkali metal phyllosilicate in finely divided form in a non-phyllosilicatic alkali metal silicate environment of the formula x M O.y SiO , in which M is an alkali metal and y/x (1.9 to 500): 1; a process for its preparation and its use in detergents and cleaners.

Sparingly soluble alkali metal silicate

The invention relates to a process for the preparation of crystalline sodium silicates having a sheet structure and high .delta. phase content from water glass, which has been prepared hydrothermally, by dehydration of the water glass and subsequent crystallization at elevated temperature, which comprises treating the water glass at temperatures of from 50 to 140.degree. C. prior to dehydration.

Process for the preparation of crystalline sodium silicates

The invention relates to a process for the preparation of crystalline sodium silicates having a sheet structure and high .delta. phase content from water glass, which has been prepared predominantly hydrothermally, by dehydration of the water glass and subsequent crystallization at elevated temperature, wherein the water glass is a mixture of water glass prepared hydrothermally and tank furnace water glass, and also to its use.

The invention relates to a process for preparing sodium disilicate in the .beta. form having a high ion-exchange capacity and a molar ratio Na.sub.2 O:SiO.sub.2 of about 1:2 from a silicate source and sodium hydroxide solution at elevated temperature, with the product formed being separated off by filtration, wherein the product is further heat treated at from 450.degree. to 780.degree. C. and/or is pressed to form compact parts.

Process for preparing sodium disilicate having a high ion-exchange

The invention relates to a granular detergent builder in the form of cogranules of a mixture of sodium bicarbonate and crystalline sheet silicates of the formula NaMSi.sub.x O.sub.2x+1 *yH.sub.2 O, where M is sodium or hydrogen, x is a number from 1.9 to 4, and y is a number from 0 to 20, wherein

Granular detergent builder

Cogranulates of high bulk density which easily disintegrate in water and comprise aluminosilicates and crystalline sodium silicates having a layered structure. The aluminosilicates contained therein are those of the formula

Process for the peparation of cogranulates comprising aluminosilicates

To prepare a compacted, granular sodium silicate having an SiO.sub.2 /Na.sub.2 O molar ratio of 1.7:1 to 4.1:1, sodium silicate having a median particle diameter of &lt;500 .mu.m is first mixed with a material increasing its hardness before being converted into pressed granules having particle sizes of 0.1 to 5 mm by compacting, comminution and screening.

Process for preparing granular sodium silicates

The present invention relates to a process for the production of crystalline sodium sheet silicate with kanemite structure with the chemical formula

Process for the production of crystalline sodium sheet silicate with

To prepare crystalline sodium disilicates having a laminar structure, a molar ratio of SiO.sub.2 to Na.sub.2 O of (1.9 to 2.1) 1 and a water content of less than 0.3% by weight, a water glass solution is first obtained by reacting sand with sodium hydroxide solution in a molar ratio of SiO.sub.2 to Na.sub.2 O of (2.0 to 2.3) : 1 at temperatures of 180.degree. to 240.degree. C. and pressures of 10 to 30 bar. This water glass solution having at least 20% by weight of solids is treated in a spray drier with hot air at 200.degree. to 300.degree. C. with the formation of a pulverulent amorphous sodium disilicate having a water content (determined as loss on heating at 700.degree. C.) of 15 to 23% by weight and a bulk density of at least 300 g/l. The spray-dried pulverulent, amorphous sodium disilicate is ground. The ground sodium disilicate is introduced into a rotary kiln equipped with devices for moving solids, externally heated via the wall and having in its interior a plurality of different temperature zones, and is treated therein at temperatures of 400.degree. to 800.degree. C. for 1 to 60 minutes with formation of crystalline sodium disilicate.

Process for the production of crystalline sodium disilicate in an

To prepare crystalline sodium silicates having a laminated structure, a molar ratio of SiO.sub.2 to Na.sub.2 O of (1.9 to 2.1) 1 and a water content of less than 0.3% by weight from a water glass solution which has a solids content of at least 20% by weight and is obtained by reaction of sand with sodium hydroxide solution in a molar ratio of SiO.sub.2 : Na.sub.2 O of (2.0 to 2.3) : 1, the water glass solution is treated with hot air of 200.degree. to 300.degree. C. in a spray drying zone to form a pulverulent, amorphous sodium silicate having a water content (determined as the loss on ignition at 700.degree. C.) of 15 to 23% by weight. The pulverulent, amorphous, water-containing sodium silicate is first ground, preferably to particle sizes of 1 to 50 .mu.m, before it is introduced into an inclined rotary tubular oven and treated in this in countercurrent with flue gas at temperatures of more than 500.degree. to 850.degree. C. to form crystalline sodium silicate. The sodium silicate issuing from the rotary tubular oven is first comminuted to particle sizes of 0.1 to 12 mm and finally ground to particle sizes of 2 to 400 .mu.m.

Process for the preparation of sodium silicates

For producing crystalline sodium silicates having a layer structure, an SiO.sub.2 /Na.sub.2 O molar ratio of (1.9 to 2.1):1 and a water content of less than 0.3% by weight from a waterglass solution containing at least 20% by weight of solids, the waterglass solution is obtained by reacting quartz sand with sodium hydroxide solution at an SiO.sub.2 /Na.sub.2 O molar ratio of (2.0 to 2.3):1 at temperatures of 180.degree. to 240.degree. C. and pressures of 10 to 30 bar. This waterglass solution is treated in a spray-drying zone with hot air at 200.degree. to 300.degree. C. for a residence time of 10 to 25 seconds and at a temperature of the exit gas leaving the spray-drying zone of 90.degree. to 130.degree. C., to form a pulverulent amorphous sodium silicate having a water content (determined as the loss on ignition at 700.degree. C.) of 15 to 23% by weight and a bulk density of more than 300 g/l. The pulverulent, amorphous, water-containing sodium silicate is introduced into an obliquely arranged rotary kiln fitted with devices for moving solids and treated therein with flue gas in countercurrent at temperatures from more than 500.degree. up to 850.degree. C. for 1 to 60 minutes to form crystalline soidium silicate. The rotary kiln is here insulated in such a way that its outside wall temperature is less than 60.degree. C. Finally, the crystalline sodium silicate emerging from the rotary kiln is comminuted by means of a mechanical crusher to grain sizes of 0.1 to 12 mm.

Process for producing crystalline sodium silicates having a layered

A process for producing amorphous sodium silicates having a water content of 0.3 to 6% by weight and an SiO.sub.2 /Na.sub.2 O molar ratio of (1.9 to 2.8) : 1 from a waterglass solution containing at least 20% by weight of solids, the water-glass solution is obtained by reacting quartz sand with sodium hydroxide solution at an SiO.sub.2 /Na.sub.2 O molar ratio of (2.0 to 2.8) : 1 at temperatures of 180 to 240.degree. C. and pressures of 10 to 30 bar. This waterglass solution is treated in a spray-drying zone with hot air at 200 to 300.degree. C. for a residence time of 10 to 20 seconds and at a temperature of the exit gas leaving the spray-drying zone of 90.degree. to 130.degree. C., to form a pulverulent amorphous sodium silicate having a water content (determined as the loss on ignition at 700.degree. C.) of 15 to 23% by weight and a bulk density of more than 300 g/l. The pulverulent sodium silicate is introduced into an obliquely arranged rotary kiln fitted with devices for moving solids and treated therein with flue gas in countercurrent at temperatures from 250.degree. up to 500.degree. C. for 1 to 60 minutes. The rotary kiln is here insulated in such a way that its outside wall temperature is less than 60.degree. C. Finally, the amorphous sodium silicate emerging from the rotary kiln is comminuted by means of a mechanical crusher to grain sizes of 0.1 to 12 mm.

Process for producing amorphous sodium silicate

In a continuous process for the preparation of phosphorous acid with simultaneous production of hydrochloric acid, a reaction zone is provided which is in open communication with a first scrubbing zone. A portion of the reaction product is recycled from the bottom of the reaction zone into the top of the scrubbing zone and phosphorous acid is removed from the circulation. Hydrogen chloride gas escaping from the top of the first scrubbing zone is brought into contact, in a cooled, second scrubbing zone, with an overstoichiometric amount of water. Hydrochloric acid is obtained which is passed as starting material into the reaction zone or into the top of the first scrubbing zone. The external cooling of the second scrubbing zone is controlled such that the temperature in the reaction zone is kept constant at a desired value between 90.degree. and 130.degree. C. without adding any external cooling or heating energy. Pure hydrochloric acid is recovered in an absorption zone.

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Monchengladbach, Germany

Alexander Tapper