Low density pet litters and methods of making such pet litters
Compacting expanded perlite fines in the presence of a small amount of binder (starch and/or clay) and water, followed by drying, produces particles with low density, good integrity, and surprisingly higher absorption by volume than non-compacted expanded perlite or non-swelling clay. Furthermore, addition of a small amount of clumping agent (e.g., guar gum) to the compacted granules results in a clumping litter with low density, good integrity and comparable clumping ability to traditional clay clumping litter.
1. A method of making a pet litter comprising:
compacting a material comprising expanded perlite fines to form a compacted material comprising expanded perlite fines, wherein the compacting is performed at a pressure from about 500 to about 1,300 psi;
breaking the compacted material comprising expanded perlite fines to form particles of the compacted material comprising expanded perlite fines;
separating the particles which have a size within a predetermined size range from a remainder of the particles;
drying the particles which have the size within the predetermined size range; and
using the dried particles as at least a portion of the pet litter, wherein the pet litter does not contain activated carbon.
2. The method of claim 1 , wherein the expanded perlite fines have a size not greater than about 600 microns.
3. The method of claim 1 , wherein the material comprising expanded perlite fines comprises about 0.5 wt. % to about 5.0 wt. % of a binder.
4. The method of claim 3 , wherein the binder is selected from the group consisting of (i) a starch, (ii) a clay, and (iii) a starch and a clay.
5. The method of claim 4 , wherein at least a portion of the binder is added to the expanded perlite fines as a dry mix before the compacting of the material.
6. The method of claim 4 , wherein at least a portion of the binder is pre-blended with water and then added to the expanded perlite fines before the compacting of the material.
7. The method of claim 1 , wherein the material comprising expanded perlite fines comprises about 15.0 wt. % to about 25.0 wt. % of water.
8. The method of claim 1 , wherein the material comprising expanded perlite fines comprises about 50 wt. % to about 85 wt. % of the expanded perlite fines.
9. The method of claim 1 , wherein the predetermined size range is about 595 microns to about 2,380 microns.
10. The method of claim 1 , wherein the particles are dried to a moisture content of about 0.25 wt. % to about 10.0 wt. %.
11. A pet litter made by the method of claim 1 .