Petroleum Coke Sieve Analysis

Question 1

Procedure

Answer 1

•visually inspect 60 and 120 mesh sieves. If necessary, use wire brush or air to remove any particles remaining. Wipe sieves and bottom retention pan with clean rag.
• weigh each sieve and pan individually and record weights
•assemble sieves with 60mesh sieve on top, 12 mesh sieve in middle and pan on bottom
•using recent cut of coke that has been through fine grinder, pour sample on 60 mesh sieve. No specific amount required although more sample used, more accurate result. Sample does not need to be weighed before adding to 60 mesh sieve
•open front doors and top cover on shaker. Lift top arm on shaker and insert sieve assembly into shaker
•place lid on 60 mesh sieve with cork side up. Adjust height if necessary by using 3/4 images wrench to lose. Both bottom pan supports. Support bottom pan before loosening. Verify bottom on is securely in place and will not vibrate loose.
•lower top arm, close top cover
• run 10 minutes
•when finished weigh 60 mesh sieve, 120 mesh sieve and pan and record weights
LIMS will do calculations, but refer to method if manual calculations necessary

Question 2

Making an adjustment

Answer 2

IMPORTANT: bottom lever is only one that requires adjustment!
•if adjustment required, analysis should be repeated after adjustment to verify changes were sufficient
•problem: 120 mesh sieve=low number. Pan=high number. Resolution = grind is too fine. Make grind less fine by lowering bottom lever
•problem: 120 mesh sieve =high number. Pan =low number. Resolution: grind is too coarse. Make grind finer by raising lower lever

Question 3

Troubleshoot

Answer 3

• verify sieves and pan clean before adding sample
• only adjust bottom lever
• verify shaker set for 10minutes not seconds
• verify any adjustment made is securely in place and has not moved
• all come from sieve analysis should be disposed of in load lugger pan. When pan full, notify garage that it needs emptied
• sieves should be cleaned using air to blow them out. Remaining particles should be brushed out using wire brush and wiping with clean cloth
• pan should be wiped with clean cloth

Question 4

Purpose

Answer 4

Ensure coke analyzed for volatile matter has been ground to appropriate test size. Particle size of coke has direct effect on volatile matter. More coarse particles, lower the VM. Other physical characteristics such as density and surface area also affected by particle size. VM analysis is useful in determining whether or not particular lot of coke meets customer specifications. Coke should be ground so 100% of particles pass through 60 mesh sieve, and 40-50% retained on 120 mesh sieve