Method for forming treated reclaimed bottom ash sand

A method for forming a treated reclaimed bottom ash sand comprising:

• providing reclaimed bottom ash sand having a moisture content of less than 15 wt %, and at least 0.5 wt % reactive aluminum;
• sizing the reclaimed bottom ash sand to a particle size of less than about ¼ inch;
• providing the reclaimed bottom ash sand to a reaction vessel;
• heating the reclaimed bottom ash sand with an aqueous composition comprising 0.5 to 3.0M NaOH in the reactor vessel to a temperature of from 40 to 70 degrees Celsius and maintaining the temperature for a time greater than about 4 hours to form a reduced metallic aluminum reclaimed bottom ash sand;
• rinsing and decanting the reduced metallic aluminum reclaimed bottom ash sand;
• removing iron from the rinsed and decanted reduced metallic aluminum reclaimed bottom ash sand to less than 5.0 wt % iron to form a treated reclaimed bottom ash sand having reduced hydrogen formation in concrete compared to the hydrogen formation of concrete utilizing reclaimed bottom ash sand;
• and
• sizing the treated reclaimed bottom ash sand to a particle size where greater than 90 wt % of the treated reclaimed bottom ash sand passes a #4 sieve;
• wherein the treated reclaimed bottom ash sand includes reactive aluminum of less than 50% by weight of the reactive aluminum in the reclaimed bottom ash and the treated reclaimed bottom ash sand includes less than 2 wt % iron.

A method for forming a treated reclaimed bottom ash sand comprising:

• providing reclaimed bottom ash sand having a particle size of less than about ⅜ inch, a specific gravity greater than 1.0, a moisture content of less than 25 wt %, at least 0.5 wt % reactive aluminum and less than 40 wt % iron;
• contacting the reclaimed bottom ash sand with an aqueous composition comprising 0.5 to 3.0M NaOH for a time greater than about 4 hours;
• rinsing and decanting the NaOH contacted reclaimed bottom ash sand;
• and
• removing iron from the rinsed and decanted reduced metallic aluminum reclaimed bottom ash sand to less than 5.0 wt % iron to form a treated reclaimed bottom ash sand having reduced hydrogen formation in concrete compared to the hydrogen formation of concrete utilizing reclaimed bottom ash sand;
• wherein the treated reclaimed bottom ash sand includes reactive aluminum of less than 50% by weight of the reactive aluminum in the reclaimed bottom ash and the treated reclaimed bottom ash sand includes less than 2 wt % iron.