What Makes Stone Water Unique?
No matter the stone processed, the resulting stone water sludge contains a very concentrated amount of suspended solids. Stone industry water is made up of small particles of stone of various sizes ranging from as small as a fraction of a micron to as large as 100’s of microns, for reference, a cross section of human hair is about 50 microns. Most of the suspended solids in the water are from 1 to 80 microns, by count they tend to be 1 to 10 microns. By overall mass the vast majority of the stone water sludge is in the 20 to 50 micron range.
What makes your slurry settle out of suspension is the size and specific gravity of the stone water particles. The higher the specific gravity and density, the faster it settles. The larger the particle the faster it settles. Some of the stone water particles can be so small that they actually will float in water for days before settling out.
Issues with Recycling:
In stone industry water suspended solids of a certain size must be removed from the recycled water due to equipment specification (saws can use straight slurry water; cnc’s need very clean water). Suspended solids also cause premature pump failure, equipment and piping clogs, and issues with trenches and pits. Suspended solids also tarnish the polish of stone surfaces (most firms find polishing with water over a certain micron rating causes finish issues on the product surface. All equipment life and reliability is affected (pumps, nozzles, hoses and components wear faster in environments with suspended solids).
An emerging issue in stone industry water is long term corrosion of metal components from a combination of pH levels and other substances (alkalinity, hardness, dissolved solids, temperature, etc) in the recycled water. This is exacerbated by chlorination – which is particularly harmful to metal surfaces on your equipment. A good solution for your stone water recycling will take corrosion into consideration.