Riffle tables

Tables usually are surfaced either with heavy battleship linoleum or with rubber. The riffles may be a clear grade of sugar pine or may be rubber strips. Such riffles usually taper from the feed end of the table to the discharge end. Almost all mill operators employ different styles of riffling table, which they believe best for their particular separations. The usual method of riffling is shown in Fig. 19-28.

The flow of mineral particles on the deck of a riffled table results in a distribution that is essentially similar to that obtained with a smooth table. However, some additional features are introduced due to the action of the riffles. In the case of a smooth table, a hydraulically classified fraction usually makes a better feed as compared with an unsized mixture. However, a classified feed does not always work best on a riffled table, and screen-sized or unsized feed is often used. The maximum particle size that can be treated in a riffled table is generally larger than that corresponding to a smooth table. 

Tables are used wet and dry. The separating action of a wet table resembles that of the traditional miner s pan. Riffled tables (Figure 10.6) are basically rectangular decks, inclined at a shallow angle to the horizontal (2 to 5°), with shallow slats (riffles) fitted to...

Tables are also used to wash coal. The reciprocating action of a table stratifies the high-gravity coal particles on the bottom and the low-gravity particles rise to the upper level of tine bed. As the low-gravity particles rise, they are moved across riffles that separate die high- and low-gravily material by the water flowing to the low side of the table deck. The refuse is trapped in the riffle troughs and the motion of the deck moves the refuse to discharge off the end.

After selection, the shale rocks were crushed, sieved, and divided into small samples by riffling. The shale samples weighed 2.5-3 g and were —6+10 U.S. Standard sieve size. The average composition of random samples chosen for chemical analysis is given in Table I. 

FIGURE 7 Subsampling (a) coning and quartering (b) table sampler [6] (c) oscillating hopper (paddle) sample divider [6] (d) spinning riffler (BSI) (e) riffle/chute splitter (BSI) if) revolving sample splitter [14]. 

FIG. 19-28 Deister-Overstrom diagonal deck table. Center, diagonal deck with pool riffle system for sand bottom, diagonal deck with pool riffle system for fine sand and slime. 

Cone and Quartering Table Sampling Spinning Riffling... 

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