Method to artificially agglomerate finely divided materials
Method to artificially agglomerate finely divided materials. A method to agglomerate finely divided material into aggregates, the aggregates being larger than the finely divided material, comprising the steps of (a) mixing finely divided material, binder and water in a mixer, (b) adding an agglomerating agent to the mix formed in step (a) and mixing constantly. Finely divided material is selected from the group consisting of cement, sand, clay, glass, slag, fly ash, stone powder, bypass dust, limestone, silica fume, crushed brick, brick powder and crushed stone or a combination thereof.
1. A method to agglomerate finely divided material into aggregates, the aggregates being larger than the finely divided material, comprising the steps of:
(a) selecting a finely divided material to form a final aggregate according to an agglomerability factor AI, the agglomerability factor AI being between 30 and 1000 and defined as
AI
=
FM
RM
×
D
90
D
10
wherein FM RM is the fineness modulus of the finely divided material used in step (a), defined as the sum of the total percentage of sample that pass a series of sieves of 0.063 mm, 0.125 mm, 0.250 mm, 0.500 mm, 1 mm, 2 mm and 4 mm,
FM RM =Σ (0.063 mm-4 mm) passing %,
wherein D 10 is the sieve size [mm] at which the passing is 10%, wherein D 90 is the sieve size [mm] at which the passing is 90% and D 90 /D 10 is a monogranular index,
(b) mixing the finely divided material, binder and water in a mixer,
(c) adding an agglomerating agent to the mix formed in step (b) and
(d) mixing constantly.
2. Method according to claim 1 , wherein in step (b) the finely divided material, binder and water are added simultaneously.
3. Method according to claim 1 , wherein in step (b) water and binder are added gradually to said finely divided material.
4. Method according to claim 1 , wherein said finely divided material is selected from the group consisting of sand, clay, glass, stone powder, bypass dust, limestone, crushed brick, brick powder and crushed stone and a combination thereof.
5. Method according to claim 1 , wherein said finely divided material is at a concentration in the range of 0.1 ton/m 3 to 3.2 ton/m 3 with respect to the final mix.
6. Method according to claim 1 , wherein said binder is selected from the group consisting of powder cement, cement mixed in water, lime, silica fume, fly ash and slag and a combination thereof.
7. Method according to claim 1 , wherein said binder is at a concentration in the range of 10 to 1000 kg/m 3 with respect to the final mix.
8. Method according to claim 1 , wherein in step (b) a superplasticizer is added to the mix.
9. Method according to claim 8 , wherein said superplasticizer is selected from the group consisting of melamine, naphthalene, lignosulfonate and polycarboxylates and a combination thereof.
10. Method according to claim 8 , wherein the solid active content of the superplasticizer is at a concentration in the range of 0.1 kg/m 3 to 10 kg/m 3 .
11. Method according to claim 1 , wherein in step (b) water to binder ratio is in the range of 0.5 to 10.
12. Method according to claim 1 , wherein said agglomerating agent is selected from the group consisting of cellulose, chitosan, polyacrylics, polyamines, polyethylene imines, polyvinylalcohols, polysaccharides, polyacrylamides, and co-polymers thereof, collagen, acrylamide, lactic acid, methacrylic acid, methacrylate, hydroxyethyl, ethylene glycol, ethylene oxide, acrylic acid, inorganic flocculants, inorganic coagulants and a combination thereof.
13. Method according to claim 1 , wherein said agglomerating agent is inorganic flocculants or polysaccharides.
14. Method according to claim 1 , wherein the solid active content of the agglomerating agent is at a concentration in the range of 0.1 kg/m 3 to 5 kg/m 3 .
15. Method according to claim 1 , wherein the aggregates obtained in step (c) are poured out of the mixer and dried for at least 6 hours.