Title of Invention

A PROCESS FOR THE PREPARATION OF CALCIUM PHOSPHATE FROM EGG SHELL WASTE

Abstract

A process for the preparation of calcium phosphate from egg shell waste comprising the steps of thoroughly washing the said waste with water crushing the washed waste to small pieces heating the washed waste to a temperature between 450 deg. C for about one and half hours with a heating rate of 150 deg. C for every half an hour and then to a temperature between 800 deg. C-900 deg. C for about three hours with a heating rate of 75 deg. C for every half an hour cooling the heated waste to room temperature, grinding and mixing the cooled waste with 200 to 250 ml of water adding 55 to 59% by weight of dominium phosphate to the solution so obtained and heating the same in a domestic microwave oven for about 20 minutes, the power output of the oven being adjusted to avoid overflow of the solution being than thoroughly washed with water containing 2 to 6 drops of ammonia and dried, to obtain phosphate.

Full Text

This invention relates to a process for the preparation of calcium phosphate from eggshell waste. Egg shells constitute about 11% of the total weight of eggs and is composed of calcium carbonate (94%) magnesium carbonate (1%) calcium phosphate (1%) and mucopolysaccharide proteins (4%). According to National Agriculture Statistic Service of the U.S.A. approximately 5 million tons of eggshell waste per year are accumulated. Occasionally some eggshells are used as fertilizers, but the greater part is stored as industrial residue with consequents pollution factor since it favours microbial action in environment. This invention proposes a simple, cost-effective and industrially viable process for the preparation of calcium phosphate from eggshell waste. The process, according to this invention, for the preparation of calcium phosphate from eggshell waste comprises the steps of thoroughly washing the said waste with water; crushing the washed waste to small pieces; heating the washed waste to a temperature between 450 deg. C for about one and half hours with a heating rate of 150 deg. C for every half an hour and then to a temperalure between 800 deg. C to 900 deg. C for about three hours with a heating rate of 75 deg. C for every half anbur, cooling the heated waste to room temperature, grinding and mixing the cooled waste with 200 to 250 m I, of water; adding 55 to 59 % by weight of di ammonium phosphate to the solution so obtained of pH 8 to 9 and heating the same at 70 C to 90 C in a domestic microwave oven for about 20 minutes, the power output of the oven being adjusted to avoid overflow of the solution during boiling, the resulting pasty substance being then thoroughly washed with water containing 2 to 6 drops of ammonia and dried, to obtain calcium phosphate. EXAMPLE 2.24 gm of waste eggshells are taken and washed with water to remove membranes adhering to the shells and to otherwise clean them thoroughly. The cleaned eggshells are crashed into small pieces. The cleaned egg shell pieces are then heated in a furnace at 450 deg. C for about one and half hour and then to a temperature between 800 to 900 deg. C for about three hours and thereafter cooled to room temperature. The shells are then ground and mixed with 200 ml of water along with 2.67 gm of di ammonnim phosphate The solution so ohtamed JS then heated at 70"C to 90^C in a domestic microwave oven for about 20 minutes, the power of the oven being adjusted to 60% to avoid overllow of the solution durmg boiling= The resulting pasty substance is then thoroughly washed with ammonia water and dried m an oven, to obtam calcium phosphate called hydroxyapatite. Yidld 4s 4-5 gm to 4 6 gm ABSTRACT A process for the preparation of calcium phosphate from egg shell waste comprising the steps of thoroughly washing the said waste with water; crushing the washed waste to small pieces; heating the washed waste to a temperature between 450 deg. C for about one and half hours with a heating rate of 150 deg. C for every half an hour and then to A temperature between 800 deg. C - 900 deg. C for about three hours with a heating rate of 75 deg. C for every half an hour; cooling the heated waste to room temperature, grinding and mixing the cooled waste with 200 to 250 ml of water; adding 55 to 59% by weight of di ammonium phosphate to the solution so obtained and heating the same in ft domestic- microwave even for about 20 minutes, the power output of the oven being adjusted to avoid overflow of the solution during boiling, the resulting paste like substance being then thoroughly washed with water containing 2 to 6 drops of ammonia and dried, to obtain calcium phosphate.

Documents:

955-che-2003-abstract.pdf

955-che-2003-claims duplicate.pdf

955-che-2003-claims original.pdf

955-che-2003-correspondence others.pdf

955-che-2003-correspondence po.pdf

955-che-2003-description complete duplicate.pdf

955-che-2003-description complete original.pdf

955-che-2003-form 1.pdf

955-che-2003-form 19.pdf

955-che-2003-form 26.pdf

955-che-2003-form 3.pdf