Construction material with improved strength and water resistance and methods of forming the same

Patent metadata

Field	Value
Publication number	US-11267755-B2
Application number	US-201715999827-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Feb 19, 2016
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The invention is directed to a mine tailing and fly ash containing construction material having improved compressive strength and water resistance. The mine tailing and fly ash containing material includes mine tailing, fly ash, an alkali solution comprising sodium hydroxide and, optionally, calcium hydroxide, and water. The invention further provides a geopolymerization method of forming a mine tailing and fly ash containing construction material.

First claim

What is claimed:

1. A mixture for the production of a construction material, the mixture consisting essentially of:
mine tailing;
fly ash;
an alkali solution comprising sodium hydroxide; and
water,
wherein the ratio of fly ash to mine tailing ranges from about 5:100 to about 20:100, based upon weight.

2. The mixture of claim 1 , wherein the mine tailing is copper-based mine tailing.

3. The mixture of claim 1 , wherein the fly ash is Class C fly ash, Class F fly ash, or a combination thereof.

4. The mixture of claim 1 , wherein the weight ratio of sodium hydroxide to mine tailing ranges from about 70:100 to about 80:100.

5. The mixture of claim 1 , wherein the alkali solution further includes Ca(OH) 2 .

6. The mixture of claim 5 , wherein the weight ratio of Ca(OH) 2 to mine tailing ranges from about 5:100 to 15:100.

7. The mixture of claim 1 , wherein the weight ratio of water to mine tailing ranges from about 150:100 to 200:100.

8. The mixture of claim 5 , wherein the weight ratio of Ca(OH) 2 to mine tailing ranges from about 5:100 to 10:100.

9. A geopolymerization method of forming a construction material, the method comprising:
(a) combining mine tailing, fly ash, an alkali solution comprising sodium hydroxide, and water to form a mixture;
(b) stirring the mixture;
(c) pouring the mixture into a mold;
(d) compressing the mixture; and
(e) curing the mixture,
wherein the ratio of fly ash to mine tailing ranges from about 5:100 to about 20:100, based upon weight.

10. The method of claim 9 , wherein step (a) is performed at a temperature of about 90-170° C. for about 40-80 minutes.

11. The method of claim 9 , wherein step (d) is performed at a forming pressure of about 3-10 MPa.

12. The method of claim 9 , wherein step (e) is performed in an oven at a temperature of about 80-120° C. for about 2-3 days.

13. The method of claim 11 , wherein step (e) is performed in an oven at a temperature of about 90° C. for about 3 days.

14. The method of claim 9 , wherein the alkali solution further comprises Ca(OH) 2 .

15. The method of claim 14 , wherein the weight ratio of Ca(OH) 2 to mine tailing in the mixture ranges from about 5:100 to 15:100.

16. The method of claim 14 , wherein the weight ratio of Ca(OH) 2 to mine tailing ranges from about 5:100 to 10:100.

17. The method of claim 9 , wherein step (d) is performed at a forming pressure of about 10 MPa.

Assignees

• Univ Arizona

Inventors

• Zhang Jinhong
• Feng Qingming

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• C04B12/005 Primary

  Geopolymer cements, e.g. reaction products of aluminosilicates with alkali metal hydroxides or silicates · CPC title

• C04B18/08

  Flue dust {, i.e. fly ash} · CPC title

• C04B28/021

  Ash cements, e.g. fly ash cements (fly ash as filler C04B18/08); Cements based on incineration residues, e.g. alkali-activated slags from waste incineration (alkali-activated combustion residues as such C04B7/243; mixtures of the lime-pozzuolane type C04B28/18); Kiln dust cements · CPC title

• C04B2111/27

  Water resistance, i.e. waterproof or water-repellent materials · CPC title