Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
176 words
In a method of forming discrete pieces or pellets from a glass-producing meltable mixture, wherein the glass-producing mixture comprises sand grains and a sodium-containing component which at least partially consists of aqueous sodium hydroxide, the improvement which comprises that the sand grains are reacted at a temperature between about 200° to 450°C for from about 5 minutes to 2 hours with the aqueous sodium hydroxide without direct contact with CO 2 , thereby to form a surface layer of water soluble silicates on the sand grains, thereafter subjecting the sand grains to a mechanical treatment in order to at least partially remove the water soluble silicates from the sand grains and thereby reducing the size of the sand grains, adding the remaining ingredients of the glass-producing mixture to the sand grains and the water soluble silicates, mixing the mixture to form a uniform mass and then agglomerating the mass in the presence of 5-15 percent by weight of water, the final pellets being non-hygroscopic and constituting an eutectic mixture and possessing good stability on prolonged storage.
Claim 2
Dependent Claim
176 words
In a method of forming discrete pieces or pellets from a glass-producing meltable mixture, wherein the glass-producing mixture comprises sand grains and a sodium-containing component which at least partially consists of aqueous sodium hydroxide, the improvement which comprises that the sand grains are reacted at a temperature between about 200° to 450°C for from about 5 minutes to 2 hours with the aqueous sodium hydroxide without direct contact with CO 2 , thereby to form a surface layer of water soluble silicates on the sand grains, thereafter subjecting the sand grains to a mechanical treatment in order to at least partially remove the water soluble silicates from the sand grains and thereby reducing the size of the sand grains, adding the remaining ingredients of the glass-producing mixture to the sand grains and the water soluble silicates, mixing the mixture to form a uniform mass and then agglomerating the mass in the presence of 5-15 percent by weight of water, the final pellets being non-hygroscopic and constituting an eutectic mixture and possessing good stability on prolonged storage.
Claim 3
Dependent Claim
14 words
The temperature of claim 1 wherein the agglomeration is effected in a mixing granulator.
Claim 4
Dependent Claim
21 words
The improvement of claim 1 wherein said mechanical treatment is effected prior to adding the remaining ingredients of the glass-producing mixture.
Claim 5
Dependent Claim
33 words
The improvement as claimed in claim 1 wherein said water soluble silicates are removed from the sand grains when the mixture is mixed to form a uniform mass in an intensive action mixer.
Claim 6
Dependent Claim
15 words
The improvement as claimed in claim 1 wherein said sodium-containing component also contains sodium carbonate.
Claim 7
Dependent Claim
25 words
The improvement as claimed in claim 1 wherein said glass-producing mixture also comprises a calcium-containing component, said calcium-containing component at least partially consisting of quicklime.
Claim 8
Dependent Claim
38 words
The improvement as claimed in claim 1 wherein said sand grains are reacted with said aqueous sodium hydroxide at a temperature of about between 350° to 400°C and for a period of about between 5 to 60 minutes.
Claim 9
Dependent Claim
28 words
The improvement as claimed in claim 1 wherein said sand grains are preheated to said elevated temperature before the sand grains are admixed with the aqueous sodium hydroxide.
Claim 10
Dependent Claim
32 words
The improvement as claimed in claim 8 wherein said preheating of the sand to said elevated temperature is effected by heating the sand grains with the flue gases from a glass-producing plant.
Claim 11
Dependent Claim
43 words
The improvement as claimed in claim 1 wherein said sand grains, prior to the admixture of said aqueous sodium hydroxide are heated to a temperature of between about 600° to 900°C whereafter said aqueous sodium hydroxide is added to the heated sand grains.
Claim 12
Dependent Claim
22 words
The improvement as claimed in claim 1 wherein said aqueous sodium hydroxide has a concentration of about between 30 to 75 percent.
Claim 13
Dependent Claim
19 words
The improvement as claimed in claim 1 wherein said aqueous sodium hydroxide has a concentration of about 50 percent.
Claim 14
Dependent Claim
48 words
The improvement as claimed in claim 1 wherein said method is carried out in batchwise manner and a portion of the reaction product of said sand grains and said aqueous sodium hydroxide obtained in a batch is recycled to a subsequent batch of sand and aqueous sodium hydroxide.
Claim 15
Dependent Claim
30 words
The improvement as claimed in claim 13 wherein the amount of said recycled portion is about between 20 to 70 percent by weight of the total amount of reaction product.
Claim 16
Dependent Claim
55 words
The improvement as claimed in claim 13 wherein the amount of said recycled portion is such that said subsequent batch absorbs the total amount of aqueous sodium hydroxide which is required for the desired ultimate composition of the glass-producing mixture to be obtained without the occurrence of sedimentation of the solid ingredients of the mixture.
Claim 17
Dependent Claim
18 words
The improvement as claimed in claim 15 wherein said amount is about 5 to 25 percent by weight.
Claim 18
Dependent Claim
68 words
The improvement as claimed in claim 1 wherein the method is carried out in batchwise manner and wherein a portion of the reaction product obtained by the reaction of the sand grains with the aqueous sodium hydroxide of a batch and after at least partial mechanical removal of said water soluble silicates from the sand grains is recycled to a subsequent batch of sand and aqueous sodium hydroxide.
Claim 19
Dependent Claim
24 words
The improvement as claimed in claim 1 wherein said glass-producing mixture additionally contains a calcium-containing component, said calcium-containing component comprising quicklime and calcium carbonate.
Claim 20
Dependent Claim
25 words
The improvement as claimed in claim 1 wherein an aluminum-containing component is added to the reaction between said sand grains and said aqueous sodium hydroxide.
Claim 21
Dependent Claim
13 words
The improvement as claimed in claim 19 wherein said aluminum-containing component is alumina.
Claim 22
Dependent Claim
35 words
The improvement as claimed in claim 1 wherein, prior to agglomerating said mass, the mass is mixed in an intensive action mixer having a mixing energy output of above 3 kW/100 kg of the mixture.
Claim 23
Dependent Claim
27 words
The improvement as claimed in claim 21 wherein said intensive action mixer has a mixing energy output of about 5 to 15 kW/100 kg of the mixture.
Claim 24
Dependent Claim
17 words
The improvement as claimed in claim 21 wherein said intensive action mixer is a counter flow mixer.
Claim 25
Dependent Claim
23 words
The improvement as claimed in claim 21 wherein the mixture after mixing in said intensive action mixer is agglomerated in the same mixer.
Claim 26
Dependent Claim
41 words
The improvement as claimed in claim 1 wherein the mixing of the mixture to form a uniform mass is effected while utilizing the heat of the reaction mixture obtained by the reaction of said sand grains with the aqueous sodium hydroxide.
Claim 27
Dependent Claim
30 words
The improvement as claimed in claim 1 wherein said pieces or pellets obtained upon the agglomeration are dried to a water content of not more than 5 percent by weight.
Claim 28
Dependent Claim
40 words
The improvement as claimed in claim 6 wherein the agglomeration is carried out in an intensive action mixer by utilizing the heat which has been evolved due to the reaction of said quicklime with the water contained in the system.
Claim 29
Dependent Claim
23 words
The improvement as claimed in claim 1 wherein said agglomeration is carried out in the presence of steam supplied to the agglomerating unit.