Disposal method and use of sewage sludge

Claim 2

A water-solids mixture hardenable under atmospheric conditions the dry solids of which comprise (based on weight % of dry solids): 1-15% lime 1-50% digested sewage sludge solids 20-90% fly ash, and the water of which provides a moisture content (based also on weight % dry solids) of 5- 50%.

Claim 3

A water-solids mixture hardenable under atmospheric conditions, as recited in Claim 1, wherein said moisture content is 15-30% and said dry solids comprise: 2-6% lime 8-20% digested sewage sludge solids 30-80% fly ash.

Claim 4

A water-solids mixture hardenable under atmospheric condition, as recited in claim 1, wherein said mixture further includes: 1-10% calcium sulfate anhydrite (based on weight % of solids).

Claim 5

A water-solids mixture hardenable under atmospheric condition, as recited in claim 2, further including: 1.5 - 3% calcium sulfate anhydrite (based on weight % solids).

Claim 6

A water-solids mixture hardenable under atmospheric condition, as recited in claim 3, further including: 10-60% soil (based on weight % solids).

Claim 7

A water-solids mixture hardenable under atmospheric condition, as recited in claim 4, further including: 20-45% soil (based on weight % solids).

Claim 8

Method of treating a sludge from a municipal sewage plant comprising admixing said sludge with lime and fly ash such that the final composition of said admixture has a moisture content of 5- 50% and the dry solids therein comprise: 1-15% lime 1-50% digested sewage sludge solids 20-90% fly ash, and permitting said admixture to harden under atmospheric conditions.

Claim 9

Method of treating a sludge from a municipal sewage plant comprising admixing said sludge with lime and fly ash such that the final composition of said admixture has a moisture content of 5- 50% and the dry solids therein comprise: 1-15% lime 1-50% digested sewage sludge solids 20-90% fly ash, and permitting said admixture to harden under atmospheric conditions.

Claim 10

Method, as recited in claim 7, wherein an alkaline earth sulfate is also included in said admixture, the amount of said sulfate in said admixture to be the molar equivalent of 1- 10% (by weight solids) calcium sulfate anhydrite.

Claim 11

Method, as recited in claim 8, wherein soil is also included in said admixture, said soil comprising 10-60% of said solids.

Claim 12

Method, as recited in claim 7, wherein said moisture content is below 35% and said admixture is compacted after placement and before being permitted to harden.

Claim 13

Method, as recited in claim 7, wherein calcium sulfate and soil are included in said admixture, and comprise, respectively, 1.5- 1.5-% (based on calcium sulfate anhydrite) and 20-45% of the solids thereof.

Claim 14

Method, as recited in claim 11, wherein said moisture content is below 35% and said admixture is compacted after placement and before being permitted to harden.

Claim 15

Hardened composition comprising the reaction product of the mixture of claim 7.

Claim 16

Hardened composition comprising the reaction product of the mixture of claim 11.

Claim 17

Hardened composition comprising the reaction product of the mixture of claim 9.

Claim 18

Method of making a load bearing material from a municipal sewage plant sludge, said method comprising admixing said sludge with lime and fly ash such that the final composition has a moisture content of 5-50%, and further comprises 1-15% lime, 1-50% digested sewage sludge solids, and 20-90% fly ash (all percentages based on weight % of solids) and permitting said admixture to harden under atmospheric conditions.

Claim 19

Method of making a load bearing material from a municipal sewage plant sludge, said method comprising admixing said sludge with lime and fly ash such that the final composition has a moisture content of 5-50%, and further comprises 1-15% lime, 1-50% digested sewage sludge solids, and 20-90% fly ash (all percentages based on weight % of solids) and permitting said admixture to harden under atmospheric conditions.

Claim 20

Method, as recited in claim 16, wherein an alkaline earth sulfate is also included in said admixture, the amount of said sulfate in said admixture to be the molar equivalent of 1-10% calcium sulfate anhydrite.

Claim 21

Method, as recited in claim 17, wherein soil is also included in said admixture, said soil comprising 10-60% of the solids of said admixture.

Claim 22

Method, as recited in claim 16, wherein calcium sulfate and soil are included in said admixture, and comprise, respectively, 1.5 -- 3% (based on calcium sulfate anhydrite) and 20-40% of the solids thereof.

Claim 23

A water-solid mixture hardenable under atmospheric conditions, the dry solids of which comprise (based on weight % of dry solids): 1-15% lime or a molar equivalent amount of hydratable alkaline earth oxide or alkaline earth metal hydroxide in a lime substitute selected from the group consisting of BOF dust, lime kiln dust or cement kiln dust, 1-50% digested sewage sludge solids, 20-90% fly ash, or an equivalent amount of a fly ash substitute selected from the group consisting of siliceous incineration residue, "alum" water treatment plant waste, or "red mud" by-product of a bauxite reduction process, and waer sufficient to provide a moisture content (based on weight % of dry solids) of 5- 50%, the combination of said materials being cementitiously hardenable under atmospheric conditions.

Claim 24

A water-solid mixture hardenable under atmospheric conditions, the dry solids of which comprise (based on weight % of dry solids): 1-15% lime or a molar equivalent amount of hydratable alkaline earth oxide or alkaline earth metal hydroxide in a lime substitute selected from the group consisting of BOF dust, lime kiln dust or cement kiln dust, 1-50% digested sewage sludge solids, 20-90% fly ash, or an equivalent amount of a fly ash substitute selected from the group consisting of siliceous incineration residue, "alum" water treatment plant waste, or "red mud" by-product of a bauxite reduction process, and waer sufficient to provide a moisture content (based on weight % of dry solids) of 5- 50%, the combination of said materials being cementitiously hardenable under atmospheric conditions.

Claim 25

A water-solids mixture hardenable under atmospheric conditions, the dry solids of which comprise (based on weight % of dry solids): 1-15% lime or a lime substitute providing a molar equivalent amount of hydratable alkaline earth oxide or alkaline earth metal hydroxide, said lime substitute comprising BOF dust, cement kiln dust, lime kiln dust, alkaline earth metal oxide or alkaline earth metal hydroxide, 1-15% digested sewage sludge solids, 1-10% calcium sulfate anhydrite or other alkaline earth metal sulfates in an amount equal to 1-10% calcium sulfate anhydrite on a molar basis, 20-90% fly ash or an equivalent amount of another waste material having pozzolanic activity selected from the group consisting of siliceous incineration residue, "alum" water treatment plant waste, or "red mud" by-product of a bauxite reduction process, and water sufficient to provide a moisture content (based on weight % of dry solids) of 5-50%, the combination of said materials being cementitiously hardenable under atmospheric conditions.

Claim 26

A water-solids mixture hardenable under atmospheric conditions, the dry solids of which comprise (based on weight % of dry solids): 1-15% lime or a lime substitute providing a molar equivalent amount of hydratable alkaline earth oxide or alkaline earth metal hydroxide, said lime substitute comprising BOF dust, cement kiln dust, lime kiln dust, alkaline earth metal oxide or alkaline earth metal hydroxide, 1-15% digested sewage sludge solids, 1-10% calcium sulfate anhydrite or other alkaline earth metal sulfates in an amount equal to 1-10% calcium sulfate anhydrite on a molar basis, 20-90% fly ash or an equivalent amount of another waste material having pozzolanic activity selected from the group consisting of siliceous incineration residue, "alum" water treatment plant waste, or "red mud" by-product of a bauxite reduction process, and water sufficient to provide a moisture content (based on weight % of dry solids) of 5-50%, the combination of said materials being cementitiously hardenable under atmospheric conditions.

Claim 27

Method of treating a sludge from a municipal sewage treatment plant comprising admixing said sludge with lime or a lime substitute material selected from the group consisting of BOF dust, lime kiln dust, cement kiln dust, hydratable alkaline earth metal oxide and alkaline earth metal hydroxide, and a pozzolanic reactant selected from the group consisting of fly ash, siliceous incineration residue, "alum" water treatment plant waste, and "red mud" by-product of a bauxite reduction process such that the final composition of said admixture has a moisture content of 5-50% (based on weight % of solids) and a dry solids content (based on weight % solids) comprising: 1-15% lime or a lime substitute providing a molar equivalent amount of alkaline earth metal hydroxide, or hydratable alkaline earth oxide, 1-50% digested sewage sludge solids, 20-90% fly ash or "fly ash equivalent amounts" of said pozzolanic reactant and permitting said admixture to harden under atmospheric conditions.

Claim 28

Method of treating a sludge from a municipal sewage treatment plant comprising admixing said sludge with lime or a lime substitute material selected from the group consisting of BOF dust, lime kiln dust, cement kiln dust, hydratable alkaline earth metal oxide and alkaline earth metal hydroxide, and a pozzolanic reactant selected from the group consisting of fly ash, siliceous incineration residue, "alum" water treatment plant waste, and "red mud" by-product of a bauxite reduction process such that the final composition of said admixture has a moisture content of 5-50% (based on weight % of solids) and a dry solids content (based on weight % solids) comprising: 1-15% lime or a lime substitute providing a molar equivalent amount of alkaline earth metal hydroxide, or hydratable alkaline earth oxide, 1-50% digested sewage sludge solids, 20-90% fly ash or "fly ash equivalent amounts" of said pozzolanic reactant and permitting said admixture to harden under atmospheric conditions.

Claim 29

Method, as recited in claim 22, wherein said mixture includes 20-90% fly ash.

Claim 30

Method, as recited in claim 22, wherein said mixture includes 1-15% lime.

Claim 31

Method, as recited in cliam 22, wherein said mixture further includes alkaline earth metal sulfate in an amount which is the molar equivalent of 1- 10% calcium sulfate anhydrite.

Claim 32

Method, as recited in cliam 22, wherein said mixture further includes alkaline earth metal sulfate in an amount which is the molar equivalent of 1- 10% calcium sulfate anhydrite.

Claim 33

A water-solids mixture, hardenable under atmospheric conditions, as recited in claim 1, further including: 10-60% soil (based on weight % solids).

Claim 34

A water-solids mixture, hardenable under atmospheric conditions, as recited in claim 2, further including: 20-45% soil (based on weight % solids).

Claim 35

Method, as recited in claim 7, wherein soil is also included in said admixture, said soil comprising 10- 60% of said solids.

Claim 36

Method, as recited in claim 7, wherein soil is included in said admixture and comprises 20-45% of the solids thereof.

Claim 37

Method, as recited in claim 29, wherein said moisture content is below 35% and said admixture is compacted after placement and before being permitted to harden.

Claim 38

Hardened composition comprising the reaction product of the mixture of claim 28.

Claim 39

Method, as recited in claim 16, wherein soil is also included in said admixture, said soil comprising 10-60% of the solids of said admixture.