Use of crystalline layered sodium silicates for softening water and a process for softening water

Claim 2

A process for softening water containing calcium and/or magnesium ions, comprising the step of softening the water with a water softening agent comprising a crystalline sodium silicate having a crystalline layered structure and the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, said crystalline layered structure appearing as layers in scanning electron microscope photographs.

Claim 3

The process as claimed in claim 1, wherein a crystalline layered sodium silicate, the characteristic reflections of which in the X-ray diffraction diagram correspond to Tables 1 to 7, is employed.

Claim 4

The process as claimed in claim 1, wherein a crystalline layered sodium silicate having the composition NaMSi 2 O 5 .yH 2 O is employed.

Claim 5

The process as claimed in claim 1, wherein a crystalline layered sodium silicate which has an end point on potentiometric titration with mineral acid is employed.

Claim 6

The process as claimed in claim 4, wherein the crystalline layered sodium silicate has an ion exchange capacity of 400 to 1,200 mmol of Na + /100 g of product (calculated as anhydrous substance).

Claim 7

The process as claimed in claim 1, wherein the water to be softened already contains sodium ions and has a pH of 8 to 12.

Claim 8

A process for softening water containing calcium and/or magnesium ions and sodium ions and with a pH of about 8 to 12, which comprises adding to the water a crystalline layered sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20.

Claim 9

A process for softening water containing calcium and/or magnesium ions and sodium ions and with a pH of about 8 to 12, which comprises adding to the water a crystalline layered sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20.

Claim 10

The process as claimed in claim 7, wherein the water to be softened contains not more than 500 mg of CaO/l and not more than 200 mg of MgO/l.

Claim 11

The process as claimed in claim 7, wherein the layered sodium silicate is employed in combination with other water softeners.

Claim 12

A process for softening water containing calcium- and/or magnesium ions, comprising the step of softening the water with a water softening agent comprising a crystalline sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, said crystalline sodium silicate having an X-ray diffraction diagram which is published in the Joint Committee on Powder Diffraction Standard under one of the following numbers: 18-1241, 22-1397, 22-1397 A, 19-1233, 19-1234, 19-1237, 23-529, 24-1123, 24-1123 A, 29-1261, 18-1242, 22-1395, 19-1235, 22-1396, 19-1236, 18-1240, 19-1232, 18-1239, 12-102, 23-703, 25-1309, 27-708 and 27-709.

Claim 13

A process for softening water containing calcium- and/or magnesium ions, comprising the step of softening the water with a water softening agent comprising a crystalline sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, said crystalline sodium silicate having an X-ray diffraction diagram which is published in the Joint Committee on Powder Diffraction Standard under one of the following numbers: 18-1241, 22-1397, 22-1397 A, 19-1233, 19-1234, 19-1237, 23-529, 24-1123, 24-1123 A, 29-1261, 18-1242, 22-1395, 19-1235, 22-1396, 19-1236, 18-1240, 19-1232, 18-1239, 12-102, 23-703, 25-1309, 27-708 and 27-709.

Claim 14

A process for softening water containing calcium- and/or magnesium ions, comprising the step of softening the water with a water softening agent comprising a crystalline sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, said crystalline sodium silicate having an X-ray diffraction reflection pattern which is shown in one of the Tables 1 through 7 of the specification.

Claim 15

A process for softening water containing calcium- and/or magnesium ions, comprising the step of softening the water with a water softening agent comprising a crystalline sodium silicate having the composition NaMSi x O 2x+1 .yH 2 O, in which M denotes sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, said crystalline sodium silicate having an X-ray diffraction reflection pattern which is shown in one of the Tables 1 through 7 of the specification.