Phosphogypsum composition having improved expansion properties
AssigneeFreeport-McMoRan Resource Partners, Limited Partnership
InventorsWillis L. Thornsberry, Jr., James T. Houston
Life of this patent
Estimating the term…
Abstract
Stabilized phosphogypsum-containing compositions with low expansion and high compressive strength characteristics are prepared by admixing phosphogypsum with a cementitious binder having a calculated zero percent tricalcium aluminate content The compositions may contain phosphogypsum and cementitious binder only or they may also include sand or other filler material. The phosphogypsum composition is wetted with water, compacted and allowed to cure. The amount of water added preferably produces a maximum density of the compacted composition.
Claims29
A stabilized phosphogypsum composition having reduced expansion comprising a mixture of:
- a. phosphogypsum;
- b. cementitious binder comprising Portland cement in an effective amount to bind said phosphogypsum, wherein the cementitious binder has a calculated tricalcium aluminate content of about zero and wherein said cementitious binder is included in the amount of about 0.5% to about 50%. based on the dry weight of the phosphogypsum;
- and
- c. water in an amount sufficient for hydration of said cementitious bin and compaction of said mixture wherein the mixture has been shaped, compacted, and cured and wherein said composition does not exhibit substantial expansion.
A method for producing a stabilized composition containing phosphogypsum comprising the steps of:
- a. admixing phosphogypsum, cementitious binder comprising Portland cement having a calculated tricalcium aluminate content of about zero, and an effective amount of water for hydration of said cementitious binder and compaction of the resultant mixture to produce a wet phosphogypsum composition, wherein the composition contains about 0.5% to 50.0% of said cementitious binder by dry weight of phosphogypsum;
- b. compacting the wet phosphogypsum composition;
- and
- c. curing the compacted, wet composition.
A method for preparing a stabilized composition comprising:
- a) blending phosphogypsum and nonreactive filler material to produce a mixture containing 20-99% phosphogypsum by weight based on the total weight of phosphogypsum and filler;
- b) admixing cementitious binder comprising Portland cement having a calculated content of tricalcium aluminate of about zero with the phosphogypsum-filler mixture of (a) in an amount to produce a composition containing 0.5 to 50.0% cementitious binder by dry weight of phosphogypsum-filler mixture;
- c) adding an effective amount of water to the composition for hydration of the cementitious binder and compaction of the resultant mixture;
- d) compacting the composition;
- and
- e) curing the compacted composition.
Dependencies are inferred from the claim text.