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Group Title: Sticky grain occurrences in sieving ( FGS: Open file report 79 )
Title: Sticky grain occurrences in sieving
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Permanent Link: http://ufdc.ufl.edu/UF00099446/00001
 Material Information
Title: Sticky grain occurrences in sieving
Physical Description: 16 p. : charts ; 28 cm.
Language: English
Creator: Balsillie, James H
Tanner, William Francis, 1917-
Williams, Holly K
Florida Geological Survey
Publisher: Florida Geological Survey
Place of Publication: Tallahassee, Fla.
Publication Date: 1999
 Subjects
Subject: Sedimentology ( lcsh )   ( lcsh )
Sediment control ( lcsh )   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
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Statement of Responsibility: by James H. Balsillie, William F. Tanner, and Holly K. Williams.
General Note: Florida Geological Survey open file report 79
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Bibliographic ID: UF00099446
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 41550461
issn - 1058-1391 ;

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State of Florida
Department of Environmental Protection
David B. Struhs, Secretary




Division of Administrative and Technical Services






Florida Geological Survey
Walter Schmnidt, State Geologist and Chief






OpenFile Repaort Nor. 79


Sticky Grain Occurrences in Sieving

by

James H. Balsil~e, Willam F. Tanner, and Holly K. Williams


Florida Geological Survey
Tallahassee, Florida
1999


ISSN 1058-1391











CONTENTS


Page
.. 1


.. 1


..2


..2


..3


. .7


. .7
. .8
10


. 11


. 15


. 15


. 15


ABSTRACT ...................


INTRODUCTION ................


BACKGROUND ........


ELECTROSTATICS .....,,,......


TYPE IV CONDITION ......


GENERAL COMMENTS ABOUT OTHER


TYPE II CONDITION .. ... .
TYPE III CONDITION .......
TYPE V CONDITION . .... .


SUMMARY ...................


ACKNOWLEDGEMENTS .. .. .. . ..


NOTE ........................


REFERENCES..................


....


....


....


....


....


TYPE


..........


..........


..........


..........


..........


CONDITIONS


FIGURES


Figure 1. Behavior of relative humidity and temperature in Ro-Tap cabinet with one
Ro-Tap machine operating (bay door closed). Initial temperature (Temp) and
relative humidities (R.H.) are listed; ensuing data points represent 15-minute
measurement intenrals. ................... ................... .


Figure 2. Examples of post-Rlo-Tapping, hand-sieving sticky grain dislodgement from
sieves. ................... ............---- -.... .......


Figure 3. Cumulative probability distribution comparison between the retained
fraction distribution and the distribution for the sticky fraction added to the
nextfiner sieve; Atsena Otie sample. ...... ~................... ....


Figure 4a. Cumulative probability distribution comparison between the retained plus
sticky distribution and the distribution where the sticky fraction is added to
the nextfiner sieve; Atsena Otie sample. ................... .......










Figure 4b. Cumulative probability distribution comparison between the retained plus
sticky distribution and the distribution where the sticky fraction is added to
the nextfinersieve; Denmarksample. ................... ........... 11

Figure 4c. Cumulative probability distribution comparison between the retained plus
sticky distribution and the distribution where the sticky fraction is added to
the next finer sieve; Escambia County (brass sieves) sample. . ... .. .. .. .. 12

Figure 4d. Cumulative probability distribution comparison between the retained plus
sticky distribution and the distribution where the sticky fraction is added to
the next finer sieve; Escambia County (stainless steel sieves) sample. .. .. .. 13

Figure 4e. Cumulative probability distribution comparison between the retained plus
sticky distribution and the distribution where the sticky fraction is added to
the nextfiner sieve; Ocala Road sample. ........,.................... 14


TABLES

Table 1. Laboratory bay and Ro-Tap cabinet conditions for examples reported in
this paper. ....,,............. ................... ... ~......... 4

Table 2. TYPE IV CONDITION sticky grain sample weight percentages and hand-sieving
times.. ................... ................ ..................6

Table 3. TYPE IV CONDITION %/-4 interval weights and sticky grain w4-4 interval
weight percentages. .................. ....... ................. 7

Table 4. TYPE IV CONDITION distribution correlation and deviation analyses
results. ................... . . . .. . - - - 8











877CKY GRAINV OCCURRENCES INV S/VIEVIG

by

J. H. Balsillie, P.G. No. 167 ', W. F. Tanner 2 and H. K. Williams 3

'Coastal Engineeri7ng Geologist, Geological/ Investigations Section, Florida Geological
Survey, 903 W. Tennessee St., Taillahassee, FL 3230e7700.
ZRegents Professor, Department of Geology, Flrada State University, Tallahassees FL 32306-3206.
"Research Assistant, M~ineral Resource Investigations and En~vironmental Geology Section,
Florida Geological Survey, 903 W. Tennessee St., Tallahassees FL 3230+7700.


ABSTRACT

Observation of sand-sized grains of predominantly quartz composition sticking to sieves
has led to the identification of five (5) TYPE COND)ITIONS occurring during sieving. One TYPE
CONDITION constitutes non-problematic sieving, one is related primarily to moisture problems,
and three to electrostatic influences. Electrostatic influences have been noted to occur when the
relative humidity becomes less than about 55% (Daeschner and others, 1959), Of the latter, one
is related to the post-sieving weighing process, one has potential to seriously affect the
cumulative distribution, and the third does not affect cumulative distribution results. While the
causes of electrostatic processes leading to sticky grain occurrences have not been identified to
the extent that solutions have been forthcoming, a manageable solution has been found for one
of the major sticky grain occurrences. (Balsillie and others, 1997).


all analysts may not be astutely observant;
fortunately the observations of one analyst
(HKW) were astute.

We have identified five (5) types of
sieving conditions which deserve
recognition; they are:

TYPE CONDITION. Sieving is
conducted without any apparent problems,
and results are accepted with confidence.
No further discussion of this condition is
needed.

TYPE II CONDITION. Sediment grains
agglomerate. The condition is due to 100%
humidity being approached within the sieve
nest, with or without condensation being
obvious.

TYPE III CONDITION. Very small
grains (relative to the mesh diameter)


INIYTODUCTIION

Sedimentologists are generally familiar
with instances where clumping of grains or
grains sticking to sieves can occur. Recent
literature dealing with analytical aspects of
sieving granulometry is, however, devoid of
reports of sticky grain problems related to
temperature and humidity. However, based
on esoteric studies in physics and chemistry
for other purposes, such problems have been
addressed to one extent or another, which
we can use as clues for our granulometry-
based problems.

Problem-free sieving may, in many
cases, be related to the "fair-weather" field
sampling and analytical schedule of the
geologist. In other cases, the analyst may
simply wait for more favorable conditions
where sieving appears to produce more
reliable results. There is also the chance that










agglomerate and/or stick to relatively very
large sieves (to both sides and undersides of
the screens), and to sieve rims. The sticking
can be attributed to electrostatic charges.

TYPE IV CONDITION. Sediment
grains only very slightly smaller than the
retaining sieve (the grains are certainly larger
than the next finer %4-9 sleve) "stick" to
retaining sieve. Following disassembly of
the sieve nest, individual sieves are hand
rotated and tapped (both suspended hand-
tapping and gentle table-tapping) wherein
grains drop readily from or through the sieve.
Sticking is, again, attributed to lower and/or
varying humidity and electrostatic causes.

TYPE V CONDITION. Another
condition can result which, not directly
occurring during sieving (although it might be
related), can fatally affect final results, and
deserves description. During the weighing
process following sieving, particles are
removed from the sieves and placed in pre-
weighed plastic or glass weighing dishes,
Electrostatic conditions occur where upon
picking up the dish from the table top (the
next step being the balance for weighing) the
grains literally explode from the dish.

BACKGROUND

In 1994, one author (JHlB) designed
anid constructed a sedimentologic/ lithologic
preparation laboratory (e.g., counter space
for preparatory and analytical work, core
splitter, drill press corer, Ro-Tap facility) in a
garage bay at the Florida Geological Survey
(FGS). One feature, specifically designed to
reduce noise from the Ro-Tap facility,
consists of an enclosed and insulated 0.9-m
-wide by 1.8-m-long by 1.5-m-high cabinet
housing two (2) Ro-Tap type sieving units,

During the fall of 1995, while
analyzing sand samples for a Florida beach
monitoring project, the sticky grain
phenomenon was observed. It began as an
obvious TYPE III CONDITION which, shortly


thereafter, changed in character (ostensibly
due to seasonal temperature and humidity
effects) to what we have here termed the
TYPE IV CONDITION (which persisted, as of
April 1996). Quantification of the TYPE IV
CONDITION and discovery of a manageable
analytical solution required, however, some
considerable work over a period of several
months. While the solution is quite
successful, we also spent considerable time
attempting to clarify the causal factors
involved. This, however, was not
forthcoming. It would, therefore, appear to
be of value to share our findings with
colleagues, that they will not have to suffer
the aggravation and loss of time that we
encountered.

The FGS garage bay preparation
laboratory is not completely insulated from
outside weather influences, because of a
vertical, rolling-type, segmented aluminum
door. The insulated Ro-Tap cabinet,
however, posed some additional concerns
because of heat generation from the Ro-Tap
machines, which may encourage static build-
up even though the Ro-Taps have been
grounded. Figure 1 illustrates four (4)
examples of the behavior of temperature and
relative humidity within the cabinet,
measured at 15-minute intervals. Some non-
linearity occurs because a cabinet door had
to be opened periodically to read the digital
temperature/relative humidity recorder. The
Ro-Tap cabinet creates a closed environment
and the increase in temperature due to heat
given off by the electric motors is
accompanied by a reduction in relative
humidity. Changes in temperature and
humidity were sizeable, ranging from '15 to
400 F and from 9 to 34 percentage points
for the relative humidity, for continuous
sieving ranging from 45 minutes (4 data
points) to 2 hours (7 data points).

ELECTROSTAT7ICS

We are not, in this paper, prepared to
address the specific source of electrostatic








































forces, or whether they are piezoelectric,
triboelectric, or hygroscopic in origin (or a
combination thereof). We can, however,
take our cue from the literature that
electrostatics is a serious problem, in
particular where the relative humidity is less
than about 55% (Daeschner and others,
1959). Such effects and influences have
been discussed by Moltini (1956), Allen
(1958), Whitby (1959), Daeschner and
others (1959), Irani and Callis (1963),
Harper (1967), Horvdth and Berta (1982),
O'Hara (1985), and M~cAteer (1990). Much
of this literature, while dealing with issues
pertinent to sieving, appears to be largely
unfamiliar to geological sedimentologists.
The terminology "sticky grain" phenomenon
has been used (if not originally coined) by
Harper (1967).

We might mention, however, that we


employed a plethora of approaches to
identify and alleviate the problem. Examples
include temperature and relative humidity
monitoring, desiccants, cleaners, humidifie rs,
surfactants, cationics, ionization, calibrated
glass beads, various grounding schemes,
etc. None, however, was successful, and
we were left with treating the symptom, not
the cause. Fortunately, a solution was
forthcoming, at least for the TYPE IV
CONDITION.

TYPEI/V CONVDITIONV

Of the sieving conditions identified
earlier we have had, so far, the opportunity
to investigate only the TYPE IV CONDITION
in any detail. Other conditions have been
identified, but shall receive in this paper,
only general discussion in a later section.


n 81.3 F 3


30 35 40 45 50 55


60 65 70 75 80 85 90 9 0


_


Temperature (deg F)
Figure 1. Behavior of relative humidity and temperature in Ro-Tap cabinet with
one Ro-Tap machine operating (bay door closed). Initial temperatures (Temp)
and relative humidities (R.H.) are listed; ensuing data points represent 1 5-minute
measurement intervals.










Table 1. Laboratory bay and Ro-Tap cabinet conditions for examples reported
in this paper.
Ro-TapAmbient Bay Conditions
Sample AnlssBy Cabinet
Dates Door Temperature Relative
Doors deg F) Humidity (%)

Atsena Otie Jan. 12, 1996 Open Closed 61.2 42
Denmark Jan. 17. 1996 Open Closed 74.5 51
Escambia Brass Dec. 22 & 26, 1995' Closed Open 58.2 to 62.1 33 to 34
Escambia Stainfess Dec. 22 & 26, 1995' Closed Open 58.2 to 62.1 33 to 34
Ocata Road Jan. 17, 1995 Open Closed 66.9 68
'Two sieve nests were used; the fine nest was Ro-Tapped on Dec. 22, 1995, the coarse nest on Dec. 26, 1995.


We have been impressed with the
consistent occurrence of the TYPE IV
CONDITION sticky grain phenomenon at the
FGS which has persisted from late October
1995 to April '1996. Testing at the Florida
State University, Department of Geology
sieving room has also resulted in identical
results, noting that the room is vented to the
outside with a 0.25 m diameter duct.

A dozen or so sand samples were
sieved at the FGS facility specifically to
quantify the effects of the TYPE IV
CONDITION on granulometric results-
Results for five (5) of the samples are
reported here. Analytical techniques are
those specified by W. F. Tanner (see
Balslilie, 1995). Sieving conditions with
respect to exposure to ambient
temperature/hum idityp conditions varied,
covering all possible combinations (see Table
1 for conditions of samples reported here)-
Following 30-minutes of Ro-Tapping, sieve
nests were carefully disassembled in
preparation for weighing. After each sieve
was removed, it was subjected to suspended
hand-tapping and gentle table tapping (i.e.,
hand-sieving) to dislodge and collect the
sticky grains. The sediment remaining on
the sieve defines the retained fraction (see
Figure 2 for definitions). TYPE IV
CONDITION sticky grain sample weight
percentages and hand sieving times for five


(5) of the tested samples are listed in Table
2. Hand-sieving times ranged from 30
seconds to 10 minutes. Total sample sticky
grain weights ranged from 2% to 1 1% of the
total sample weights.

Samples listed in Table 2 include a
beach sample from Atsena Otie Key (Big
Bend coast of Florida), a beach ridge sample
from the Jerup beach ridge plain of Denmark,
an Escambia County, Florida, beach sample,
and an upland sample from a locality along
Ocala Road in Tallahassee, Florida. Samples
were comprised of clean, predominantly to
exclusively quartz, sand-sized sediments.

Po st- Ro-Ta p hand-sieving quickly
resulted in dislodging sticky grains. Typical
examples are plotted in Figure 2 illustrating
that sticky grain dislodgement and collection
tends to become complete (i.e., asymptotic)
after about: 30 to 60 seconds of hand-
sieving.

During investigation of the
phenomenon, speculation arose concerning
the effect of stainless steel sieves (both
screens and rims) used at the FGS. Sample
splits were therefore prepared and sieved
using both the stainless steel sieves and all
brass sieves (both screens and rims).
Results for the Escambia County, Florida
beach sample splits are listed in Table 2, and



































and assess the nature of the sticky grain
occurrence.

The TYPE IV CONDITION can lead to
three analytical outcomes. These are:

1. The sticky fraction is added back to (i.e.,
retained in) the l/-4 sieve to which it was
sticking. This scenario would occur if the
analyst was not aware of a sticky grain
problem, and was very careful not to
dislodge any grains during the sieve nest
disassembly and weighing process.

2. Sticky fraction is added to the next finer
%-9 sieve. This scenario is the optimal
condition where the analyst was alert,
recognized the occurrence, and took
appropriate action (i.e., hand-sieving and
adding the sticky grains to the next finer
sieve) .

3. The sticky grain fraction is lost. This
would occur if the analyst was not aware of
the sticky grain problem and during sieve
nest disassembly and weighing, and any
dislodged grains were not recovered (i.e.


we = weight of grains sticking to 1/4-phi sieve.
Wr = weight of grains retained on 1/4-phi aieve after 120 s.
Retaining 120 a 120 a
Sieve Wr We
+1.00 phi 0.520 g 0.124 g
a 1.25 phl 1.723 g 0.192g


O 1.50 phi 3.215 g
Li 1.75 phi 12.008 g
v 2.00phi 14.015 g
O 2.25 phi 9.740 g
m 2.50 phi 4.424 g


0.468 g
0.265 g
0.103 g
0.257 g
0.152 g


I~


~


so Ibo


I $oo r
Hand-Sieving Time (s)


Figure 2. Examples of post-Ro-Tapping, hand-sieving sticky grain
dislodgment from sieves.


indicate that both brass and stainless steel
sieves result in sticky grain occurrences.

TYPE IV CONDITION W-phi screen
interval total weights (retained plus sticky
grains) and sticky grain 1/-phi interval weight
percentages are listed in Table 3. It is
especially important to note that for a single
1/-0 interval the weight percent of sticky
grains can be sizeable (up to 40%1 of the
total in some cases). In many cases,
however, this occurs because only a few
grains, of both retained and sticky material,
are involved. Hence, a few grains may result
in a large weight percent change. Where
large numbers of grains are involved, percent
sticky material commonly represents 5 to
10% of the total for a typical 1/-0 interval,

The ultimate issue, of course, is how
all this affects final granulometric outcomes.
The very fortuitous answer is that the
effects are insignificant, provided that
reasonable care is exercised when
dismantling sieve nests and emptying sieves
in preparation for weighing. This includes
frequent use of the microscope to search for











Table 2. TYPE IV CONDITION sticky grain sample weight percentages and hand-sieving times.
Escambia Escambia -
Atsena Otie Denmark Ocala Road
All Brass AHl Stainless
Screen
4 Hand Hand Hand Hand Hand
Sticky Sticky Sticky Sticky Sticky
ineral Weight See Weight iee Weight lee Weight Sve Weight Sev
Time Time Time Time Time
(s) (s) (s) (s) (s)

-1.25 to -1.00 0 000 30
-1.00 to -0.76 0.000 3011 0 000 30 0.000 30
-0.75 to -0.50 0.000 30 0 .000 30 0.000 30
-0.60 to -0.25 0.000 30 0 .000 30 0.000 30
-0.25 to 0.00 0.000 30 0.033 30 0.029 30
0.00 to 0.25 0.000 30 0 .059 30 0.232 30
0.25 to 0.50 0.023 30 0.352 30 1.125 30
0.50 to 0.75 0.035 30 0.000 30 1.455 30 1.735 30 0.009 30
0.75 to 1.00 0.226 60O 0.027 30 2.357 30 2.085 30 0.246 120
1.OD to 1.25 0.741 120 0.163 30 2.770 30 0.869 301 0.379 120
1.25 to 1.50 1.642 150 0.783 30 1.836 30 1.076 30 0.926 120
1.50 to 1.75 2.237 600 0.449 30 1.833 30 0.734 30 0.525 120
1.76 to 2.00 1.446 600 0.331 30 0.212 30 0.310 30 0.204 120
2.00 to 2.25 0.801 300 0.126 30 0.123 30 0.083 30 0.508 120
2.25 to 2.50 0.333 180 0.099 30 0.015 30 0.021 30 0.300 120
2.50 to 2.75 0.244 60 0.043 30 0.003 30 0.001 30 0.107 30
2.75 to 3.00 0.024 60 0.000 30 0.005 30 0.000 30 0.056 30
3.00 to 3.25 0.002 30 0.000 3D 0.000 30 0.000 30 0.070 30
3.25 to 3.50 0.000 30 0.000 30 0.008 30 0.007 30 0.036 30
3.50 to 3.75 0.000 30 0.000 30 0.002 30 0.002 30 0.040 30
3.75 to 4.00 0.000 30 0.000 30 0.000 30 0.002 30 0.007 30
Pan

Total Sticky
Wegh % 5.316 2.020 11.061 8.310 3.411

Total Sample
Wegt() 68.244 38.973 45.352 47.322 5 0.592

N OTE:
Weight % = sticky weights divided by t* tal sample weights, where the total sample
weight is the total retained plus total sticky weights for the sample.


lost) and not added to the next finer sieve.

The analytical effect of outcomes can
be demonstrated by comparing resultant
granulometric statistics. Outcome 3 is
unacceptable since the distribution would be
censored (Tanner, 1964) which, with a
modicum of analytical attention and care,
should not occur.


Outcome 2, the optimal or desired
result, can be compared to samples
represented by retained fractions only.
Numerical results quantifying comparability
for each sample are listed in Table 4. The
worst case example encountered is plotted
on probability paper (Figure 3) to illustrate


the negligible difference between the two
cumulative probability distributions.

A more inclusive demonstration of the
negligible difference is to compare the two
outcomes where (a) the sticky fraction is
added back to the retained fraction (outcome
1) versus (b) the sticky fraction is added to
the next finer fraction (outcome 2). This
latter cumulative probability distribution
comparison is, in fact, more than necessary
to assess comparability. Numerical results
of Table 4, and probability plot examples of
Figures 4a through 4e illustrate the negligible
effect (NOTE: dashed lines in Figures 3 and
4ca through4e represent the fitted theoretical
Gaussian distribution, it is the departure of











Table 3. TYPE IV CONDITION %~-9 interval weights and sticky grain %/-9 interval weight
percentages.
Escarnbia- Escarnbia -
Atsena Otie Denmnark Ocala Road
AII Brass AII Stainless

Screen Weight Weight Weight Weight Weight
$ % % %6 %6 %
Total Total Total Total Total
Interval Sticky Sticky Sticky Sticky Sticky
Weight Weight Weight Weight Weight
g) per per per per per
Interval Interval Interval Interval Interval

-1.25 to -1.00 0.010 0.000
-1.00 to -0.75 0.020 0.000 0.026 0.000 0.000 0.000
-0.75 to -0.50 0.027 0.000 0.000 0.000 0.020 0.000
-0.50 to -0.25 0.019 0.000 0.052 0.000 0.034 8.752
-0.25 to 0.00 0.025 0.000 0.126 11.924 0.155 16.076
0.00 1o0.25 0.020 0 .000I I 0.538 4.980 0.683 26.315
0.25 to 0.50 0.067 23.661 2.130 7.492 2.022 18.187
0.50 to 0.75 0.188 12.533 4.596 14.367 4.515 10.732 0.019 25.269
0.75 to 1.00 0.807 21.641 0.043 24.590 8.144 13.123 9.195 3.223 0.643 19.325
1.n00to 1.25 2.538 20.099 0.386 16.416 9.796 12.823 12.762 6.043 1.914 10.024
1.25 to 1.50 4.263 26.293 1.306 23.378 11.104 7.499 8.427 5.290 3.684 12.713
1.50 to '1.75 11.163 13.676 5.669 3.089 5.685 14.623 6.562 7.152 12.274 2.163
1.75to 2.00 15.243 6.474 10.741 1.200 2.161 4.439 2.050 5.723 14.118 0.730
2.00ta 2.25 17.747 3.078 13.215 0.370 0.669 8.312 0.687 5.918 9.997 2.571
2.25 to2.50 12.156 1.871 6 .788 0.569 0.215 3.111 0.164 3.615 4.576 3.315
2.50 to 2.75 3.442 4.832 0.703 2.362 OsO42 2.885 0.017 2.381 0.947 6.671
2.7 to 3.00 0.494 21.469 0.076 0.000 0.043 4.861 0.004 0.000 0.423 10.117
3.00 to 3.25 0.063 1.90)2 0.028 0.000 0.005 4.255 0.001 41.975 0.351 8.105
3.2 to 3.50 0.018 0.0010 0.011 0.000 0.010 36.634 0.008 38.095 0.226 7.634
3.50 to 3.75 0.006 0.000 0.003 0.000 0.004 0.000 0.002 28.571 0.262 1.875
3.7 to 4.00 0.005 0.000 0.002 0.000 0.002 0.000 0.003 0.000 0.215 0.000
Pan 0.014 0.003 0.000 0.005 0.011 0.945

Total Weight 68.244 38.973 45.352 47.322 50.592

NOTE:
Total Weight = retained plus sticky weight for the %-4 interval.


sample data from the Gaussian that allows
for identification of environmental
conditions). It is to be noted that r2 values
of Table 4 are all essentially unity even
though Ya-@ classes can have an average
weight percent deviation of up to about
0.5%, or a maximum weight percent
deviation of up to about 3%.


There is the possibility that the
vertical motion of the Ro-Tap device results
in grains also passing backward (i.e.,
upward) through the supradjacent (~,
coarser) sieve. Hand-sieving by one author
(JHB) has demonstrated that this
phenomenon does occur. The phenomenon
in combination with the existence of


opposing charges of screen and particles
(albeit very small) would increase the
probability that the smaller grains would be
"retained" by the coarser sieve. This
explanation is, however, purely speculative.

GENERAL COMWMENVTS ABOUT
OTHER TYPE CONVDIT/IONS


TYPE HI CONVDITIONV


This condition ostensibly involves
condensation within the sieve nest, causing
grains to clump and stick to the sieves due
to excess moisture accumulation. This might
occur if a sieve nest is taken from an air
conditioned environment (colder and driver









Table 4. TYPE IV CONDITION distribution correlation and deviation analyses results.
Average Maximum Average Maximum
Sample r' n Deviation Deviation Deviation Deviation
(g) (g) (%) (%1)
Retained Fraction Only versus Sticky Fraction
Passed to Next Finer Sieve

Atsena Otie 0.9990 22 0.242 1.526 0.164 1.223
Denmnark 0.9995 14 0.074 0.305 0.299 0.800
Escambia Co. Brass 0.9977 21 0.239 1 1256 0.448 1.883
Escambia Co. Stainless 0.9994 21 0.187 0.987 0.127 0.635
Ocala Road 0.9997 15 0.115 0.468 0.146 0.589
Sticky Fraction passed on to Next Finer Sieve versus sticky Fraction
Added back to Retaining Sieve
Atsene Orie 0.9984 22 0.139 0.611 0.354 2.237
Denmark 0.9997 14 0.044 0.242 0.144 0.783
Escambia Co. Brass 0.9952 21 0.120 0.735 0.527 2.770
Escambia Co. Stainless 0.9978 21 0.104 0.575 0.396 2.085
Ocala Road 0.9994 15 0.084 0.276 0.227 0.926
NOTES:
r" = square of the Pearson Product-Moment Correlation Coefficient based on weight data;
n=number of %-0 data pairs; deviations are based on differences between weights (g) and
cumulative probability distribution percentiles (%) for each V-# interval; individual %-# class
data for the second data set above are listed in Table 2 columns labelled "Sticky Weight %".


air) into a non-air conditioned Ro-Tap
environment (warmer and more humid alr).
It may or may not be exacerbated due to
electrostatic effects, although they probably
are minimized since high humidity releases
static charge buildup. The condition has
been reported to occur sporadically at the
Florida State University, Department of
Geology sedimentologic sieving facility,
during summer months when both
temperature and humidity were large in
magnitude (WFT). The condition, however,
has not occurred during the course of this
study.

TYPEHI1 CONDITIONS

During a period of time in the fall of
1995, the TYPE III CONDITION sticky grain
phenomenon occurred at the FGS. It was
readily observable with the naked eye" and
even more impressive using a binocular
microscope fitted with a calibrated ocular.
During December of 1995 the TYPE 1Ill
CONDITION sticky grain phenomenon was


reported to occur at the environmentally
controlled sedimentologie facility at Louisla na
State University (LSU) using a Gilsonic Auto
siever with 4-inch screens (Greg Stone, John
Ellis, personal communications). Solutions
for solving the problem include treating the
sand sample with Anstac-M or Technistat A
(Daeschner and others, 1959) or Aluminum
Oxide C ( Job n Ell is, pe rsonal
communications). Sieving results using the
latter treatment at LSU were was successful
in subduing electrostatic effects which
caused grains to stick to the sieves (Greg
Stone, personal communications).

One must be aware that it is possible
not to immediately recognize the difference
between TYPE Ill and TYPE IV
CONDITIONS. One could easily mistake one
for the other. Determination of the type of
stickiness can be made through frequent use
of the microscope, a recommendation
emphasized by Daeschner and others
(1959).

It is also of importance to note that a





-A~ssna Otia Key, Florida,
_ bech sand sample.


:T a I I_


O Sticky fraction added
to next finer sieve.
* Retained sample only.


" r I i A _L I


F p 1.974 1 l980
a 0.401 0.401


1 su a


_~


-17.829


So age


I I


1 I _ I 1___~__~___ L~ I


e .P


g ig I II a' l" l g g I


gil


95
9
8


- 99.

S99.

-99,
-99
-98


s


-1


-82



- 8.1
- e.e


-o.701

8.381


-o.785

e.een


-15.978


ech tal


176.554


193.110


r I


I I


B.01 L
-2


-1 8 1 2
Phi Grain Size~


3 -4 5


Figure 3. Cumulative probability distribution comparison between the
retained fraction distribution and the distribution for the sticky fraction
added to the next finer sieve; Atsona Otie sample (thin dashed lines
represent the theoretical Gaussian distributions based on the means and
standard deviations of the samples).


TYPE III CONDITIONI more nearly affects the
tails of the distribution. The resulting
outcome can be seriously affected (i.e., in
error) because it is the tails of the
distribution which control the character of
the central or model portion of the
distribution, not vice versa (Doeglas, 1945;


Balsillie, 1995). By comparison, the TYPE IV
CONDITIONI more nearly affects either the
entire distribution or its central portion;
hence, the distribution tails are not as
severely impacted.






































































to occur using a test sample. The nature of
occ urre nce might vary depending on the type
of weighing dishes used, bench or table top
composition, balance conditions, etc. We
have found that an anti-static, grounded
digitizing-type pad seems to discourage the
TYPE V CONDITION. It is quite possible,


I Irr


I


I


I Ill


-Atson Otle Key, Florida,
- bleah snd sample.


- O Stiecky fraction added
to net finer slv.:
+ Sticky frctin adekd
back to retaining slae..


I I I IMI 1 1


r 1.974 1.054

4 0.401 0 .410

Gk -0.701 06887

K 8 .361 156.02


1 me I I


oth11 MM 17Cs.554 1512.812


99199


MI;


.95
9P -


- 99.
- 99.
- 99.

- 99.
- 99
- 90

- 95


5


- 48
- 30

- EB
- 18
- 10

-5



-1
- 8.5

- 8.2
- 1
- B.B!


-16.878


-1 8.880


~Ti


"
it


' ,,


',, ,


,,,~,,,


%8.1


3 4 5


-2 -1 B 1 2
Phi Brain Size


Figure 4a. Cumulative probability distribution comparison between the
retained plus sticky distribution and the distribution where the sticky
fraction is added to the next finer sieve; Atsona Onie sample (thin dashed
Hines represent the theoretical Gaussian distributions based on the means
and standard deviations of the samples).


nIYP V coirDITNW


On any given day (depending on local
temperature and humidity conditions, etc.)
and prior to sieve nest dismantling, grain
collection, and weighing, one might first
determine if a TYPE V CONDITION is likely








99. 99


$8.1" "
-2 -1 a 1 2 3 4 5
Phi Grain Size

Figure 4b. Cumulative probability distribution comparison between that
for the retained plus sticky distribution and the distribution where the
sticky fraction is added to the next finer sieve; Denmark sample (thin
dashed lines represent the theoretical Gaussian distributions based on
the means and standard deviations of the samples).


however, that other situations will require
innovative alternatives to address the
problem.

SUMMHIARY

Sedimentologists are familiar with


sticky grain occurrences during sieving. This
study has resulted in identifying five (5)
types of sieving conditions of which four (4)
involve stic ky grains. One condition
constitutes problem-f ree sieving
(CONDITION TYPE 1), another is related to
condensation in the sieves and problematic































0 Sticky fraction added
to next finer sieve.


~t-~t~l


Measure C1 +

p 1.188 1.181
r o .4ae o.4as


6 A 1 I I r


LB I I


99. 99


P. ,


99.
99.
99
90


Escambia Co., Florida,
beach sample, all brass
slwavs.


,. ,, .


,,,


I


I 'a


* St~cky fraction added
back to retaining sieve.


- .5
- 8.2
- 0.1
- 85


-g
1r


0.002


0.024


4.324

5.642


4.388

%.286


Stl mI I


d "


1


,-'


soImi M


78.584


as.739


I L I


B.B1


-2 -1


8 1 2 3 4q
Phi Brain Size


Figure 4c. Cumulative probability distribution comparison between the
retained plus sticky distribution and the distribution where the sticky
fraction is added to the next finer sieve; Escambia County (brass sieves)
sample (thin dashed lines represent the theoretical Gaussian distributions
based on the means and standard deviations of the samples).


clumping of grains (CONDITION TYPE II).
The remaining three (3) are related to
electrostatic influences. Of the latter, one
occurs where very srnall grains stick to the
upper coarser sieves (CONDITION TYPE
III), another (CONDITION TYPE IV) occurs
where grains only very slightly smaller than


the retaining sieve (but larger than the next
finer I/-4 sieve) stick to the retaining sieve,
and the last can affect the post-sieving
weighing process (CONDITION TYPE V).

During the course of this study at the
FGS, we have encountered CONDITION








99. 99


8.01" "'- '""""'"
-2 -1 0 1 2
Phi Girain Size


3 4 5


Figure 4d. Cumulative probability distribution comparison between that
for the retained plus sticky distribution and the distribution where the
sticky fraction is added to the next finer sieve; Escambia County
(stainless steel sieves) sample (thin dashed lines represent the theoretical
Gaussian distributions based on the means and standard deviations of
the samples).


without additional investigation they might
appear to be the same. They are not.
CONDITION TYPE III can significantly
affect resulting statistics because the coa rse
tail of the distribution is affected.
CONDITION TYPE IV more nearly affects


TYPES III, IV, AND V. CONDITION TYPE
V, while not directly a sieving problem
(although it might be related), requires
careful attention as discussed in text.
CONDITIONS III and IV, however, occur
during sieving and pose problems because









99.99


0.01 ' ' ' '
-2 -1 B 1 2
Phi Grain Size


-3 4 5


Figure 4e. Cumulative probability distribution comparison between that
for the retained plus sticky distribution and the distribution where the
sticky fraction is added to the next finer sieve; Ocala Road sample (thin
dashed lines represent the theoretical Gaussian distributions based on
the means and standard deviations of the samples).


the central part or entire distribution; its
effect on resulting statistics describing the
distribution has been demonstrated to be
insignificant. These outcomes provide
physical evidence that it is the tails of the
probability distribution which determine the
character of the central portion of the


distribution, not: vice versa. The type of
condition can readily be determined using a
microscope fitted with a calibrated ocular;
its frequent use is considered vital to
successful sieving granulometry.








Balsillie, J. H., 1995, William F. Tanner on
environmental elastic granulometry:
[W. F. Tanner, ed.], Florida
Geological Survey, Special Publication
No. 40, 144 p.

Balsillie, J. H., Tanner, W. F., and Williams,
H. K., 1 997, Sticky grain occurrences
in sieving: Geological Society of
America, Abstracts with Programs, v.
29, p. 3.

Daeschner, H. W., Seibert, E. E., and Peters,
E. D., 1959, Appication of
electroformed precision micromesh
sieves to the determination of particle
size distribution: Symposium on
Pa article Size Measurement, American
Society for Testing Materials, ASTM
Special Technical Publication No.
234, p. 26-49.

Doeglas, D. J., 1946, Interpretation of the
results of mechanical analyses:
Journal of Sedimentary Petrology, v.
18, p. 19-40.

Harper, W. R., 1967, Contact and frictional
electrification, Oxford, Clarendon
Press, 369 p.

Horybth, T., and Berta, I., 1982, Static
elimination, Chichester, Wiley and
Sons, 115 p.

Irani, R. R., and Callis, C. F., 1963, Particle
size: measurement, interpretation,
and application, New York, Wiley and
Sons, 165 p.

McAteer, O. J., 1990, Electrostatic
discharge control, New York,
McGraw-Hill, 480 p.


ACKNIOWLEDGEMENTS

The authors wish to thank the
fol lowi ng i nd ivid uals for cons ultatio n se prices
and suggestions regarding the sticky grain
phenomenon: D. H. Baisillie, Kenneth M.
Campbell, Rick Green, Mark Grozos, Ted
Kiper, David O'Hara, William C. Parker, and
John Prutsman. Geologists and
sedimentologists Gregory Stone and John
Ellis at Louisiana State University, who were
also expe rie nc ing sieving problems,
contributed to this work. We wish to thank
Kenneth M. Campbell, Rick Green, and
Walter Schmidt for comments on the original
draft, and Jacqueline MI. Lloyd and William
C. Parker for comments and valuable
discussion leading to the final form of the
manuscript. We wish to also acknowledge
the outside reviews of Frank W. Stapor, Jr.,
and an anonymous reviewer for their
comments. Other selected staff of the
Florida Geological Survey who provided
editorial comments are Jon Arthur, Paulette
Bond, Joel Duncan, Frank Rupert, and
Thomas M. Scott; their contributions are
here acknowledged.

This work was, in part, supported by
the Big Bend Coastal Wetlands Study, U. S.
Geological Survey/Florida Geological Survey
cooperative agreement 14-08-0001-AO915.

NOTE

Citation of trade names in this paper
does not constitute official endorsement of
such products.

R;FEENVCE S

Allen, Mi., 1958, Kill static in lab screening:
Chemical Engineering, v, 65, no. 19,
p. 176.








Moltini, E., 1956, Screening analysis powder
particle analysis: particle-size
determination by screen analysis:
Industria Mineraria, (Rome), v. 7, p.
771-784; [Abstracted in] Applied
Mechanics Reviews, 1958,v. 11, no.
1, p. 48.

O'Hara, D. B., 1985, Free electron charging
of fine particles for electrostatic
precipitation [M. S. Thesis]:
Tallahassee, FL, Florida State
University, Department of Physics,
59 p.

Tanner, W. F., 1964, Modifications of
sediment size distributions: Journal
of Sedimentary Petrology, v. 34, no.
1, p. 156-164.

Whitby, K. T., 1959, The mechanics of fine
sleving: Symposium on Particle Size
Measurement, American Society for
Testing Materials, ASTM Special
Technical Publication No. 234, p. 3-
26.




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