Riffle splitter

The bottom ash was sampled by emptying one of the four grates below the furnace at the start of the run. At the completion of the run this grate was re-emptied onto the floor. This sample was allowed to cool, and then a 10-gal milk can was filled with the ash sample. This sample was then split with a riffle splitter to obtain a 16-oz representative aliquot. 

Coal and Ash Analysis. The coal and ash samples were separated into 20-40 g representative samples in the laboratory by a small riffle splitter. These samples were then pulverized with a mortar and pestle. The moisture content was determined by weighing the sample, drying it at 103 °C, and then reweighing it. These samples were kept in a desiccator and were subsequently used for the mercury analysis. 

Riffle splitters (rifflers) are used frequently on the plant floor and in labs to mix as well as to subsample solid particles. An example is shown in Figure 3.11. 

Figure 3.11 Typical riffle splitter used for subsampling solid particles.

Using these values, the total sample size for this raw material is 2.4 kg to be assured that the sample analysis is within 10% of the true assay of the lot 90% of the time. This entire 2.4-kg sample would need to be finely ground, and a representative sample for the marker analysis would need to be split out using a riffle splitter. These calculations also show that a sufficiently large preship sample must be obtained from the raw material vendor to accurately measure the expected marker content in a given lot. 

Second, easily flowing granules or powder may be riffled. This is recommended for fertilizers Oohnson, 1990b). Riffle boxes (sample dividers or splitters) are available to BS812 and BS1377 from ... 

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]. 

---