FOAMED GLASS HYDROPONIC SUBSTRATE

摘要

A foamed glass plant growth support structure, including a foamed glass substrate and a plurality of interconnected pores distributed throughout the substrate. The substrate is characterized by a porosity of at least about 65 percent. The pore size is substantially between about 0.2 and about 2 millimeters and the substrate is sufficiently chemically stable such that water filling the plurality of interconnected pores experiences a pH shift of less than 0.5.

主权项

1. A method of producing chemically stable foamed glass for use as a plant growth medium, comprising the steps of:
a) combining a foaming agent, a pH control agent, and particulate waste glass to define an admixture having from about 1 weight percent to about 5 weight percent foaming agent and from about 1 weight percent to about 3 weight percent pH control agent with the remainder being particulate waste glass; b) drying the admixture at temperatures between about 400 degrees Fahrenheit to about 450 degrees Fahrenheit; c) after drying, sintering the admixture at temperatures between about 1300 and about 1500 degrees Fahrenheit; d) foaming the admixture at temperatures ranging from between about 1450 degrees Fahrenheit and about 1600 degrees Fahrenheit to yield a soft foamed glass body; e) curing the soft foamed glass body at temperatures between about 1560 degrees Fahrenheit and about 1580 degrees Fahrenheit; f) cooling the soft foamed glass body at temperatures between about 1400 degrees Fahrenheit and about 1550 degrees Fahrenheit; and g) immediately after f), quenching the softened foamed glass body with flowing air at room temperature to yield a foamed glass substrate; wherein the substrate includes at least about 65 volume percent interconnected pores; wherein the pores have diameters between about 0.2 mm and about 2 mm; wherein the pore walls have a crazed microstructure; and wherein the pores include a pH buffering agent available for aqueous dissolution.