Portable sluice box

A portable sluice box adapted to be carried conveniently to an operating location and to be positioned in a stream of water for classification of mineral particulate from detritus containing the same, said sluice box having a front upstream end, a rear downstream end, a longitudinal axis extending from said front end to said rear end, and a transverse axis, said box comprising:

• a. infeed table means, including upstanding first sidewalls and a first bottom wall at a first level for receiving and confining a charge of mineral-containing detritus for fluid compelled movement along a path lying in a material handling plane generally coincident with said first bottom wall of said table means, said infeed table means having an open upstream end to receive an inflow of the stream of water over said first bottom wall and an open downstream end to discharge the charge under the influence of the moving stream;
• b. a classification table means arranged to have, relative to said infeed table means, an operating position where said classification table means is secured to said infeed table means so as to extend therefrom in a downstream direction, said classification table means comprising two upstanding second sidewalls and a second bottom wall positioned at a second level below said first level, said classification table means having a foraminous separation plate which, with the classification table means in said operating position, is at a level above said second bottom wall but no higher than said first level and extending between said two second sidewalls, said classification table means having a substantially open upstream end which, with the classification table means in said operating position, communicates with the open downstream end of said infeed table means to receive the inflow of the stream of water and said charge that passes over said first bottom wall and thence onto said separation plate along a primary path;
• said classification table means being further arranged to have, relative to said infeed table means, a collapsed position for carrying, where said classification table means and said infeed table means are positioned adjacent one another in general overlying relationship;
• c. riffle means disposed transversely in a longitudinally spaced array beneath said separation plate and above said second bottom wall, said riffle means defining with said separation plate an upper flow channel intermediate said riffles and said separation plate through which water and particulate may pass along a secondary flow path and defining with said second bottom wall a lower channel intermediate said riffles and said second bottom wall;
• d. a retention mat positioned in said lower channel;
• e. inlet channel means at a juncture of said infeed and classification table means, disposed at a height beneath said separation plate and beneath said first bottom wall of said infeed table means, and above said second bottom wall of said classification means, said inlet channel means extending substantially across the full transverse extent of said classification table and facing in an upstream direction to receive an inflow of water from said stream of water to flow directly to said secondary flow path.