Zeolitic tuff: water pollution, agriculture, and building applications

Methods for production of a colored metal oxides pigment, nano-structured milky calcium and magnesium hydroxides, and nano-structured philipsite and magnesioferrite from zeolitic tuff. The methods comprises the steps of mixing pulverized zeolitic tuff with hydrochloric acid to form an aqueous colored acid solution. Thereafter, the aqueous acid colored solution is separated from the residue of pulverized zeolitic tuff by decantation and filtration. The aqueous acid colored solution is treated with sodium hydroxide solution and adjusts the pH at 5.0 to form colored precipitate. The colored precipitate is separated and subjected to drying to obtain brown-red metal oxides pigment. The filtrate also treated with sodium hydroxide and adjusted the pH at 11.0 to form white milky suspended nanoparticles particles from calcium and magnesium mixed hydroxides. Thereafter the residue of zeolitic tuff was treated with a mixture of water and ethanol (50/50 % by volume to separate the white fine particles (philipsit mineral) from the brown-reddish particles (magnesioferrite). These ultra fine particles can be used in printing inks and paper coatings.