Use of animal by-products for cement production

Patent metadata

Field	Value
Publication number	US-2022298067-A1
Application number	US-202217696714-A
Country	US
Kind code	A1
Filing date	Mar 16, 2022
Priority date	Mar 19, 2021
Publication date	Sep 22, 2022
Grant date	—

Abstract

A raw meal and clinker are provided based on animal by-products, such as bone ash. The resulting cement contains clinker phases such as: tricalcium phosphate (TCP), calcium sulfoaluminate (CSA), calcium aluminate phases (CA, CA 2 , CA 6 , C 12 A 7 , among others), hydroxyapatite (HA), and minor phases (anhydrite, lime, among others).

First claim

What is claimed:

1 . A raw meal of a cement clinker, comprising:
about 20-70 weight percent calcium oxide; about 0-15 weight percent silicon dioxide; about 20-70 weight percent aluminum oxide; about 0-15 weight percent iron oxide; about 2.5-35 weight percent sulfur trioxide; about 0-5 weight percent magnesium oxide; about 0-5 weight percent sodium oxide; and about 0-50 weight percent phosphorus pentoxide.

2 . The raw meal of claim 1 incorporating animal by-product.

3 . The raw meal of claim 2 , wherein that animal by-product is selected from a group consisting of animal bones, bone ash and combinations thereof, or any material with high contents of calcium oxide and phosphorus pentoxide.

4 . The raw meal of claim 3 , further including at least one of calcium hydroxide, limestone, hydrated lime, aluminum hydroxide, anhydrous calcium sulfate, hemihydrate calcium sulfate, dehydrate calcium sulfate, calcium fluoride.

5 . The raw meal of claim 4 , including about 30-45 weight percent calcium oxide.

6 . The raw meal of claim 5 , including about 0-2.5 weight percent silicon dioxide.

7 . The raw meal of claim 6 , including about 30-50 weight percent aluminum oxide.

8 . The raw meal of claim 7 , including about 0-1 weight percent iron oxide.

9 . The raw meal of claim 8 , including about 5-15 weight percent sulfur trioxide.

10 . The raw meal of claim 9 , including about 0-1 weight percent magnesium oxide and about 0-1 weight percent sodium oxide.

11 . The raw meal of claim 10 , including about 10-20 weight percent phosphorus pentoxide.

12 . A cement clinker made from the raw meal of claim 2 .

13 . A cement clinker, comprising:
about 10-90 weight percent calcium sulfoaluminate; about 5-50 weight percent tricalcium phosphate; about 0-75 weight percent calcium aluminates; and about 0-25 weight percent minor phases including at least one of anhydrite calcium sulfate, hydroxyapatite and free lime.

14 . The cement clinker of claim 13 , including about 30-65 weight percent calcium sulfoaluminate.

15 . The cement clinker of claim 14 , including about 20-40 weight percent tricalcium phosphate.

16 . The cement clinker of claim 15 , including about 5-25 weight percent calcium aluminates.

17 . The cement clinker of claim 16 , including about 0-10 weight percent minor phases including at least one of anhydrite calcium sulfate, hydroxyapatite and free lime.

18 . A process for producing a cement clinker, comprising:
preparing a raw meal of about 20-70 weight percent calcium oxide, about 0-15 weight percent silicon dioxide, about 20-70 weight percent aluminum oxide, about 0-15 weight percent iron oxide, about 2.5-35 weight percent sulfur trioxide, about 0-5 weight percent magnesium oxide, about 0-5 weight percent sodium oxide, and about 0-50 weight percent phosphorus pentoxide; compacting and forming pellets from the raw meal; calcining the pellets at about 900-1,000° C. for about 15-120 minutes; clinkering the pellets at about 1,100-1350° C. for about 15-120 minutes to produce clinkered pellets; and quenching the clinkered pellets in air.

19 . The process of claim 18 , including incorporating animal by-product into the raw meal.

20 . The process of claim 19 , including selecting the animal by-product from a group of animal by-products consisting of animal bones, bone ash and combinations thereof.

21 . The process of claim 20 , including calcining the pellets for about 30-90 minutes.

22 . The process of claim 21 , including clinkering the pellets at about 1,200-1,300° C. for about 45-75 minutes.

Assignees

• Univ Kentucky Res Found

Inventors

• Duvallet Tristana
• Jewell Robert B

Classifications

• C04B2111/00215

  Mortar or concrete mixtures defined by their oxide composition · CPC title

• C04B7/44

  Burning; Melting · CPC title

• C04B7/323 Primary

  Calcium aluminosulfate cements, e.g. cements hydrating into ettringite · CPC title

• C04B7/28 Primary

  from combustion residues, {e.g. ashes or slags from waste incineration}({C04B7/243} , C04B7/26 take precedence) · CPC title

• C04B7/24

  Cements from oil shales, residues or waste other than slag · CPC title