The present invention makes clear and defines a congruent composition of a langasite-based oxide, and establishes a method of manufacturing a crystal by any desired composition of AE.sub.3ME.sub.1+a(Ga.sub.1−xAl.sub.x).sub.3+bSi.sub.2+cO.sub.14 (AE is an alkaline-earth metal, ME is Nb or Ta, 0≤x≤1, −0.5<a≤0 or 0<a<0.5, −0.5<b≤0 or 0<b≤0.5, and −0.5<c≤0 or 0<c<0.5, excluding a=b=c=0). This makes it possible to suppress the formation of an impurity, and improve the yield and crystal manufacturing rate. The raw material is a raw material mixture prepared by mixing an alkaline-earth metal or its carbonate or oxide, Nb or Ta or its oxide, Ga or its oxide, Al or its oxide, and Si or its oxide.

The present invention makes clear and defines a congruent composition of a langasite-based oxide, and establishes a method of manufacturing a crystal by any desired composition of AE.sub.3ME.sub.1+a(Ga.sub.1−xAl.sub.x).sub.3+bSi.sub.2+cO.sub.14 (AE is an alkaline-earth metal, ME is Nb or Ta, 0≤x≤1, −0.5<a≤0 or 0<a<0.5, −0.5<b≤0 or 0<b≤0.5, and −0.5<c≤0 or 0<c<0.5, excluding a=b=c=0). This makes it possible to suppress the formation of an impurity, and improve the yield and crystal manufacturing rate. The raw material is a raw material mixture prepared by mixing an alkaline-earth metal or its carbonate or oxide, Nb or Ta or its oxide, Ga or its oxide, Al or its oxide, and Si or its oxide.

Provided is powdered gyrolite-type calcium silicate that has a relatively large particle size, yet is endowed with both a high oil absorption and a high particle strength. The powdered gyrolite-type calcium silicate has (1) an oil absorption of at least 2.8 mL/g, (2) an average particle diameter of at least 40 μm, and (3) in treatment where the gyrolite-type calcium silicate is charged into a laser diffraction-type particle size analyzer within the range of a diffraction volume of from 0.1 to 0.6 and circulated at a flow rate of 32.5 mL/s for 5 minutes, a percent change in average particle diameter following treatment with respect to average particle diameter before treatment of 15% or less.

Provided is powdered gyrolite-type calcium silicate that has a relatively large particle size, yet is endowed with both a high oil absorption and a high particle strength. The powdered gyrolite-type calcium silicate has (1) an oil absorption of at least 2.8 mL/g, (2) an average particle diameter of at least 40 μm, and (3) in treatment where the gyrolite-type calcium silicate is charged into a laser diffraction-type particle size analyzer within the range of a diffraction volume of from 0.1 to 0.6 and circulated at a flow rate of 32.5 mL/s for 5 minutes, a percent change in average particle diameter following treatment with respect to average particle diameter before treatment of 15% or less.

A crystalline solid electrolyte includes: Li.sub.3PO.sub.4, Li.sub.4SiO.sub.4, and Li.sub.3BO.sub.3 and content of the Li.sub.3PO.sub.4 is less than or equal to 75 mole %.

A method for destructing and valorizing an asbestos waste including the steps of: determining the asbestos mineralogical group contained in the waste, performing a treatment on the waste which includes of: an acid treatment when the waste comprises only a chrysotile, a base treatment when the waste comprises only an amphibole, the acid treatment followed by the base treatment when the asbestos waste includes a mixture of a chrysotile and an amphibole, and valorizing at least one of the products obtained on completion of the performing of the treatment. An embodiment also concerns a treatment of a chrysotile waste through an acid treatment followed by a thermal treatment.

A method for destructing and valorizing an asbestos waste including the steps of: determining the asbestos mineralogical group contained in the waste, performing a treatment on the waste which includes of: an acid treatment when the waste comprises only a chrysotile, a base treatment when the waste comprises only an amphibole, the acid treatment followed by the base treatment when the asbestos waste includes a mixture of a chrysotile and an amphibole, and valorizing at least one of the products obtained on completion of the performing of the treatment. An embodiment also concerns a treatment of a chrysotile waste through an acid treatment followed by a thermal treatment.

A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350° C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350° C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

The present invention relates to a method of treating liquids with an alkaline earth metal silicate to reduce contaminants, a filtered liquid obtained by this method, the use of the method in the wine production process and a filter aid comprising an alkaline earth metal silicate.