Alkali metal silicate composition with potassium compound additive

• US 5,344,633 A
• Filed: 06/14/1993
• Issued: 09/06/1994
• Est. Priority Date: 11/14/1990
• Status: Expired due to Fees

• Current Assignee: Eka Nobel AB (Nouryon Coöperatief UA)
• Original Assignee: Eka Nobel AB (Nouryon Coöperatief UA)
• Inventors: Sorensson, Olle, Severinsson, Krister
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): HORTON, KENNETH
• Application Number:
  US08/075,926
• Time in Patent Office: 449 Days
• Field of Search: 423/332, 423/333, 423/334, 252/135
• US Class Current: 423/333
• CPC Class Codes: C01B 33/325 After-treatment, e.g. purification or stabilisation of solutions, granulation; Dissolution; Obtaining solid silicate, e.g. from a solution by spray-drying, flashing off water or adding a coagulant
• CPC Class Codes: C11D 3/08 Silicates

Abstract

The invention concerns a solid alkalimetal silicate having a molar ratio SiO₂ :M₂ O from about 1.5 to about 3, in which M is an alkalimetal substantially consisting of sodium and potassium. The silicate contains from about 1 and up to about 5% by weight of K₂ O based on the dry material and the water content being from about 16 to about 25% by weight based on the total weight.

Further, the invention concerns a method of its preparation, its use and a cleaning agent composition containing the silicate above.

Claims

1. Solid alkali metal silicate having a molar ratio SiO₂ :

M₂ O from about 1.5 to about 3, in which M is an alkali metal comprising sodium and potassium, the silicate containing from about 1 and up to about 5% by weight of K₂ O based on the dry material and the water content being from about 16 to about 25% by weight based on the total weight.

2. Alkali metal silicate as claimed in claim 1, wherein it has a bulk density exceeding about 800 g/l.

3. A method of preparing a silicate according to claim 1, the method comprising the steps:

(a) drying an aqueous solution of an alkali metal silicate to a solid state having a water content from about 16 to about 25% by weight, the alkali metal silicate having a molar ratio SiO₂ ;

M₂ O from about 1.5 to about 3 in which M is an alkali metal comprising sodium and potassium;

(b) adding one or more potassium compounds to the solution prior to the drying or to the dry material in an amount so that the product will contain from about 1 to about 5% by weight of K₂ O based on the dry material.

4. A method as claimed in claim 3, wherein potassium carbonate, potassium hydroxide or potassium silicate is added prior to the drying.

5. A method as claimed in claim 3, wherein the drying is performed in a spray dryer.

6. A method of preparing a silicate according claim 2, the method comprising the steps:

(a) drying an aqueous solution of an alkali metal silicate to a solid state having a water content from about 16 to about 25% by weight, the alkali metal silicate having a molar ratio SiO₂ ;

M₂ O from about 1.5 to about 3 in which M is an alkali metal comprising sodium and potassium;

(b) adding one or more potassium compounds to the solution prior to the drying or to the dry material in an amount so that the product will contain from about 1 to about 5% by weight of K₂ O based on the dry material.

7. A method as claimed in claim 4, wherein the drying is performed in a spray dryer.