The invention discloses porous, bioactive glass and glass ceramic morsels or pellets to be used as tissue graft substitute materials and processes for obtaining the same wherein the bioactive glass and glass ceramic morsels or pellets are made up of natural agents like phosphate, calcium, sodium and other elements which are not alien to the human or animal body. The said preparation process encompasses various steps like quenching sintering, foaming, and sol-gel casting which render the glass morsels or pellets unique bioactivity and enhanced porosity which may facilitate tissue repair and augmentation during tissue graft replacement.

To provide a method for recycling a solar cell module glass, which enables development of other novel applications of a waste glass of a solar cell module while controlling an elution amount of Sb from the waste glass into water. Disclosed is a method for recycling a solar cell module glass, the method comprising: grinding a solar cell module glass into a glass powder; adding at least one foaming agent selected from SiC, CaCO.sub.3 and a seashell, and a particular inhibitor to the glass powder to produce a mixture; and heating the mixture to 700 to 1,100 C. to produce a foam glass.

To provide a method for recycling a solar cell module glass, which enables development of other novel applications of a waste glass of a solar cell module while controlling an elution amount of Sb from the waste glass into water. Disclosed is a method for recycling a solar cell module glass, the method comprising: grinding a solar cell module glass into a glass powder; adding at least one foaming agent selected from SiC, CaCO.sub.3 and a seashell, and a particular inhibitor to the glass powder to produce a mixture; and heating the mixture to 700 to 1,100 C. to produce a foam glass.

To provide an opaque quartz glass having excellent heat insulating property, mechanical strength and surface smoothness, a silica powder water slurry of concentration of 45 to 75 wt % is subjected to wet pulverization with silicon nitride beads having a mean diameter of 0.1 mm to 3 mm. The silica powder and silicon nitride beads are subjected to abrasion and the silicon nitride powder works as foaming agent and independent spherical bubbles are formed for manufacturing opaque quartz glass which has air cells having a mean diameter of 2 to 30 m and are independent spherical, having a density of 1.90 to 2.20 g/cm.sup.3, a whiteness of 80 or more, a reflectance of 80% or more for light of a wavelength of 0.2 to 3 m at thickness of 3 mm, a bending strength of 70 MPa or more, a surface roughness Ra of the baked surface of 0.7 m or less.

To provide an opaque quartz glass having excellent heat insulating property, mechanical strength and surface smoothness, a silica powder water slurry of concentration of 45 to 75 wt % is subjected to wet pulverization with silicon nitride beads having a mean diameter of 0.1 mm to 3 mm. The silica powder and silicon nitride beads are subjected to abrasion and the silicon nitride powder works as foaming agent and independent spherical bubbles are formed for manufacturing opaque quartz glass which has air cells having a mean diameter of 2 to 30 m and are independent spherical, having a density of 1.90 to 2.20 g/cm.sup.3, a whiteness of 80 or more, a reflectance of 80% or more for light of a wavelength of 0.2 to 3 m at thickness of 3 mm, a bending strength of 70 MPa or more, a surface roughness Ra of the baked surface of 0.7 m or less.

Concrete may be melted to form a glass product. Methods and batch compositions including concrete may be used to produce amorphous silica materials including, but not limited to, glass, container glass, fiber glass, glass bead, glass spheres, sheet or plate glass, glass aggregate, glass sand, abrasives, proppants, foamed glass, and manufactured glass articles. The initial processing steps include preparing a melt batch comprising concrete and, optionally, other components, melting the melt batch, and cooling the melted melt batch. Further processing steps may be utilized to produce the glass article.

The invention provides a process for preparing a porous glass, comprising mixing borosilicate glass powder with calcium carbonate particles to form a mixture, sintering the mixture at a temperature in the range from 750 to 850 C. to obtain a sintered body, cooling the sintered body and leaching calcium carbonate from the cooled sintered body with the aid of an acid. The invention also provides a process for the preparation of one or more alkaline earth metal silicates by reacting a vitreous material and an alkaline earth carbonate, optionally in the presence of a transition metal or post-transition metal oxide, at a temperature lower than 1200 C., to form a composite consisting of one or more alkaline earth metal silicates and a residual glass, and optionally recovering the one or more silicates.

The invention provides a process for preparing a porous glass, comprising mixing borosilicate glass powder with calcium carbonate particles to form a mixture, sintering the mixture at a temperature in the range from 750 to 850 C. to obtain a sintered body, cooling the sintered body and leaching calcium carbonate from the cooled sintered body with the aid of an acid. The invention also provides a process for the preparation of one or more alkaline earth metal silicates by reacting a vitreous material and an alkaline earth carbonate, optionally in the presence of a transition metal or post-transition metal oxide, at a temperature lower than 1200 C., to form a composite consisting of one or more alkaline earth metal silicates and a residual glass, and optionally recovering the one or more silicates.

A method of making a roadbed, including paving an area with foamed glass bodies to define a bed and covering the bed with a layer of cementitious material to define a composite bed. The composite bed is at least 85 percent foamed glass bodies. The composite bed has a cementitious surface.

A method of making a roadbed, including paving an area with foamed glass bodies to define a bed and covering the bed with a layer of cementitious material to define a composite bed. The composite bed is at least 85 percent foamed glass bodies. The composite bed has a cementitious surface.