A sluice box is described comprising two walls, and a plurality of riffles. Riffles can have a first portion that extends below the bottom panel of a sluice box (or the bottom of a flow), and a second portion that extends above the bottom panel of a sluice box (or the bottom of a flow). By creating a catch in a riffle by having a portion of the riffle extend below a bottom panel of a sluice box, heavier minerals are not washed away as quickly, if at all, as with other sluices.

A sifting apparatus for stratifying raw material includes a material feed-in device, a material support unit, a gas plenum, and a discharge control device. The material support unit receives material from the material feed-in device and has a surface having a plurality of openings for a gaseous medium introduced from underneath the material support unit, thereby effecting loosening and stratification of the material into a layer of relatively heavier material, and a layer of relatively lighter material atop the heavier material. The introduced gaseous medium originates in a pump, is collected in a pressurized reservoir and is controlled by a metered valve prior to introduction to the material support unit.

A system and associated method constructs a building material from lunar soil. A magnetic sorter magnetically sorts the lunar soil and the system creates a layered surface comprising a microwave susceptible, thermal conductive top layer of lunar soil and a poorly microwave-susceptible and poorly thermally conductive sublayer of lunar soil. A microwave generator generates microwave energy into an antenna and directs the microwave energy onto the top layer of lunar soil to sinter the microwave susceptible, thermal conductive top layer of lunar soil.

A system and associated method constructs a building material from lunar soil. A magnetic sorter magnetically sorts the lunar soil and the system creates a layered surface comprising a microwave susceptible, thermal conductive top layer of lunar soil and a poorly microwave-susceptible and poorly thermally conductive sublayer of lunar soil. A microwave generator generates microwave energy into an antenna and directs the microwave energy onto the top layer of lunar soil to sinter the microwave susceptible, thermal conductive top layer of lunar soil.