Methodology Appendix: Particle Size Analysis Wet Sieving Procedure Equipment needed: Metal tray, riffle box, oven set to 100oC, weight balance, bucket, stirrer, 50g/l sodium hexametaphosphate, stainlesssteel sieves, O-rings, sieve shaking apparatus. 1. A sample of >400g is needed for wet sieving -dependingupon the maximum clast size. ?2. Samples need to be dried in the oven (at least 70o C) beforeanalysis.
?3. Split the sample using the riffle box in order to extract asubsample for the laser granulometer. The sample may need to be split a numberof times in order to extract a c.5g subsample. ?4. Once the subsample is extracted, amalgamate the remainingsample. ?5. Weigh the dried sample to 2 decimal places using the coarsebalance 1.
?6. Add the sample to a clean bucket and cover with water fromthe tap. ?7. Add 100ml 50g/l Sodium hexametaphosphate solution (breaksthe sediment down).
?8. Stir the sample for a few minutes. ?9. Select sieves ranging from 16mm (-4ø) mesh diameter to 250?m(2ø) mesh diameter. Around 8 to 9 sieves aresufficient. ?10.
Stack thesieves in order from highest mesh diameter to lowest (250?m or 2ø should be atthe bottom of the stack). Place a rubber O-ring between each sieve. ?11. Place thebase pan on the sieve shaker with the outlet/tube facing into the sink.
?12. Place thesieve stack onto the base pan. Ensure there is an O-ring between the final sieveand the base pan and that the sieve stack is attached securely. ?13.
Carefullypour the sample from the bucket into the top of the sieve stack. Ensure thatthe portion <250 ?m is pouring out of the outlet and into the sink. Wash thebucket ?out with water until it is clean. ?14. Attach thelid of the sieve shaker and secure it using the twin-nuts. The lid should be fittedwith a tube attached to a tap. ?15. Ensure thelid is securely fastened and turn on the tap.
There is an attachment within thesieve shaker lid that will spray the sample with water. Ensure the water isrunning freely through the sieve stack and into the sink. ?16. If thewater is running freely, switch on the sieve shaker.
The amplitude should beset to at least 2 and the sieve shaker should run for 5 to 10 minutes, untilthe water flowing out the sieve stack runs clear. ?17. When theshaking stops, turn off the tap and allow all water to pass through the sieves.?18. Remove thelid, remove each sieve and place into the oven at c.80o C.
Check each sieve isclean before removing from the sieve stack and ensure that the O-ring isremoved before the sieve is placed in the oven. ?19. Dry thesieves containing sediment at 80o C overnight.
?20. Once dryweigh the portion of the sediment that is retained on each sieve. ?