Temperature gelation activated aqueous silicate mixtures and process of forming impermeable gels

Claim 2

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble silicate and an activator which reacts above said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkyl aryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms and W-is an aldehyde group.

Claim 3

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts above said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an aklylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is a sulfonyl group.

Claim 4

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts above said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an aklylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is a sulfonyl group.

Claim 5

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts at said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: ##STR2## wherein: R is a hydrocarbon radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; n is an integer in the range of from 1 to 3; and M is a cation of alkali metal, alkaline earth metal or ammonium ion.

Claim 6

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts at said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: ##STR2## wherein: R is a hydrocarbon radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; n is an integer in the range of from 1 to 3; and M is a cation of alkali metal, alkaline earth metal or ammonium ion.

Claim 7

The aqueous silicate mixture of claim 3 wherein: R is an alkyl radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine and combinations thereof; n is an integer in the range of from 1 to 3; and M is an alkali metal cation.

Claim 8

The aqueous silicate mixture of claim 3 wherein: R is a linear alkyl radical having in the range of from 1 to 3 carbon atoms in the linear chain; n is an integer in the range of from 1 to 3; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or mixtures thereof.

Claim 9

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at or above a certain temperature level comprising at least one compound of the formula: ##STR3## wherein: R is an alkyl radical having in the range of from 1 to 3 atoms; X is a halogen radical substituent on the terminal carbon atom of R of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 10

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at or above a certain temperature level comprising at least one compound of the formula: ##STR3## wherein: R is an alkyl radical having in the range of from 1 to 3 atoms; X is a halogen radical substituent on the terminal carbon atom of R of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 11

The aqueous silicate mixture of claim 6 wherein: R is an alkyl radical having one carbon atom; X is a halogen radical substituent and is fluorine, chlorine or a combination thereof; and M is a cation of sodium, potassium or combinations thereof.

Claim 12

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR4## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 13

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR4## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 14

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium, and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR5## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 15

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium, and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR5## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 16

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR6## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 17

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR6## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 18

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR7## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 19

A pumpable aqueous silicate mixture which can be gelled to a solid comprising water, a water soluble silicate of sodium, potassium and combinations thereof, and an activator which produces acid or acid equivalents at and above a certain temperature level comprising at least one compound of the formula: ##STR7## wherein: M is a cation of sodium, potassium or combinations thereof; and wherein said activator is present in said mixture in an amount such that at or above said certain temperature level said activator lowers the pH of said mixture and gels said mixture.

Claim 20

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts above said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is an aldehyde group, a sulfonyl group, the acid equivalent of such radicals or combinations thereof.

Claim 21

An aqueous silicate mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature comprising water, a water soluble metal silicate and an activator which reacts above said given temperature to gel said mixture, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is an aldehyde group, a sulfonyl group, the acid equivalent of such radicals or combinations thereof.

Claim 22

A process of selectively forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of from about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration in said mixture of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkyl aryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is an aldehyde group; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 23

A process of selectively forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of from about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration in said mixture of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkyl aryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl radicals having in the range of from 6 to 10 carbon atoms; and W is an aldehyde group; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 24

A process of selectively forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of from about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration in said mixture of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixture with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl atoms having in the range of from 6 to 10 carbon atoms; and W is a sulfonyl group and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 25

A process of selectively forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of from about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration in said mixture of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixture with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: X.sub.n R-W wherein: n is an integer in the range of from 1 to 6; X is a halide substituent on an alpha chain, a a terminal carbon or both; R is an alkyl radical, an aryl radical or an alkylaryl radical with the alkyl radicals having in the range of from 1 to 6 carbon atoms and the aryl atoms having in the range of from 6 to 10 carbon atoms; and W is a sulfonyl group and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 26

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: ##STR8## wherein: R is a hydrocarbon radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; n is an integer in the range of from 1 to 3; and M is a cation of alkali metal, alkaline earth metal or ammonium ion; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 27

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature: ##STR8## wherein: R is a hydrocarbon radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; n is an integer in the range of from 1 to 3; and M is a cation of alkali metal, alkaline earth metal or ammonium ion; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 28

The process of claim 15 wherein: R is an alkyl radical having in the range of from 1 to 3 carbon atoms; X is a halogen radical substituent of fluorine, chlorine and combinations thereof; n is an integer in the range of from 1 to 3; and M is an alkali metal cation.

Claim 29

The process of claim 15 wherein: R is a linear alkyl radical having in the range of from 1 to 3 carbon atoms in the linear chain; n is an integer in the range of from 1 to 3; X is a halogen radical substituent of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or mixtures thereof.

Claim 30

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature; ##STR9## wherein: R is an alkyl radical having in the range of from 1 to 3 atoms; X is a halogen radical substituent on the terminal carbon atom of R of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 31

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate mixed with water below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate per 100 ml total aqueous mixture above said given temperature; ##STR9## wherein: R is an alkyl radical having in the range of from 1 to 3 atoms; X is a halogen radical substituent on the terminal carbon atom of R of fluorine, chlorine or combinations thereof; and M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 32

The process of claim 18 wherein: R is an alkyl radical having one carbon atom; X is a halogen radical substituent and is fluorine, chlorine or a combination thereof; and M is a cation of sodium, potassium or combinations thereof.

Claim 33

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR10## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 34

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR10## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 35

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR11## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 36

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR11## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 37

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR12## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 38

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR12## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 39

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR13## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.

Claim 40

A process of forming an impermeable gel comprising the steps of: mixing water, a water soluble metal silicate and an activator to form a mixture which does not gel for a period of time below a given temperature but which rapidly gels at temperatures above said given temperature, said aqueous silicate mixture having a pH in the range of about 9 to 13 at a temperature below said given temperature and said activator being at least one compound of the following formula present in said mixture at a concentration to produce a total acid or acid equivalent concentration of less than about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate below said given temperature and above about 20 milliequivalents per 16 milliliters of concentrated aqueous silicate above said given temperature: ##STR13## wherein: M is a cation of sodium, potassium or combinations thereof; and gelling said mixture by increasing the temperature of said mixture to said given temperature.