ASTM C50/C50M-13(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C50/C50M − 13 (Reapproved 2019)
Standard Practice for
Sampling, Sample Preparation, Packaging, and Marking of
Lime and Limestone Products
This standard is issued under the fixed designation C50/C50M; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope C110 Test Methods for Physical Testing of Quicklime,
Hydrated Lime, and Limestone
1.1 This practice covers procedures for the collection and
C400 Test Methods for Quicklime and Hydrated Lime for
reduction of samples of lime and limestone products to be used
Neutralization of Waste Acid
for physical and chemical tests.
C1271 Test Method for X-ray Spectrometric Analysis of
1.2 This practice further covers inspection, rejection,
Lime and Limestone
retesting, packing, and marking of lime and limestone products
C1301 Test Method for Major and Trace Elements in Lime-
as it may be used in the chemical, agricultural, and process
stone and Lime by Inductively Coupled Plasma-Atomic
industries.
Emission Spectroscopy (ICP) and Atomic Absorption
(AA)
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. Within the text, the D2234/D2234M Practice for Collection of a Gross Sample
of Coal
inch-pound units are shown in brackets. The values stated in
each system may not be exact equivalents; therefore, each D3665 Practice for Random Sampling of Construction Ma-
terials
system shall be used independently of the other. Combining
values from the two systems may result in non-conformance E105 Practice for Probability Sampling of Materials
E122 Practice for Calculating Sample Size to Estimate,With
with the standard.
Specified Precision, the Average for a Characteristic of a
1.4 This standard does not purport to address all of the
Lot or Process
safety concerns, if any, associated with its use. It is the
E141 Practice for Acceptance of Evidence Based on the
responsibility of the user of this standard to establish appro-
Results of Probability Sampling
priate safety, health, and environmental practices and deter-
E177 Practice for Use of the Terms Precision and Bias in
mine the applicability of regulatory limitations prior to use.
ASTM Test Methods
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1 accuracy—a term generally used to indicate the reliabil-
mendations issued by the World Trade Organization Technical
ity of a sample, a measurement, or an observation and is a
Barriers to Trade (TBT) Committee. measure of closeness of agreement between an experimental
result and the true value.
2. Referenced Documents
3.2 bias (systematic error)—an error that is consistently
2.1 ASTM Standards:
negative or consistently positive. The mean of errors resulting
C25 Test Methods for Chemical Analysis of Limestone,
fromaseriesofobservationswhichdoesnottendtowardszero.
Quicklime, and Hydrated Lime
3.3 chance error—error that has equal probability of being
positive or negative. The mean of the chance errors resulting
from a series of observations that tends toward zero as the
This practice is under the jurisdiction of ASTM Committee C07 on Lime and
number of observations approach infinity.
is the direct responsibility of Subcommittee C07.06 on Physical Tests.
Current edition approved Dec. 1, 2019. Published December 2019. Originally
3.4 combined water—water that is chemically bonded to
approved in 1922. Last previous edition approved in 2013 as C50/C50M – 13. DOI:
calcium or magnesium oxide to form hydrate.
10.1520/C0050_C0050M-13R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.5 error—the difference of an observation or a group of
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
observations from the best obtainable estimate of the true
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. value.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C50/C50M − 13 (2019)
3.6 free water—water that is not chemically bonded to divided by the number of observations less one (degrees of
calcium or magnesium oxide. freedom); the square of the standard deviation (or standard
error).
3.7 grosssample—a sample representing one lot of material
and composed of a number of increments on which neither
4. Significance and Use
reduction nor division has been performed.
4.1 The following practices are to be used in obtaining
3.8 increment—a small portion of the lot collected by one
samples that are representative of the lot being sampled. The
operation of a sampling device and normally combined with
methodology used will be dependent upon the size and type of
other increments from the lot to make a gross sample.
material sampled and testing requirements.
3.9 laboratory sample—refers to the sample after the initial
preparation from which the analytical sample is obtained. 4.2 Thefollowingpracticesareintendedforuseinobtaining
samples from material that is ready for sale and are not
3.10 lot—a discrete quantity of material for which the
intended as sampling procedures for quality control purposes.
overall quality to a particular precision needs to be determined.
These practices are to be used in obtaining a laboratory sample
3.11 precision—a term used to indicate the capability of a
that will yield results serving as a basis for acceptance or
person, an instrument, or a method to obtain repeatable results;
rejection of the lot of material sampled. This does not preclude
specifically, a measure of the chance error as expressed by the
the use of these practices for quality control purposes.
variance, the standard error, or a multiple of the standard error
4.3 The following practices can be used to eliminate bias in
(see Practice E177).
sampling. The person or persons responsible for using these
3.12 representative sample—a sample collected in such a
practices must be trained and they will be conscientious and
manner that every particle in the lot to be sampled is equally
timely in their use.
represented in the gross or divided sample.
4.4 An agreement between the producer and the consumer
3.13 sample—a quantity of material taken from a larger
on location of sampling, either at the producer’s plant or at the
quantity for the purpose of estimating properties or composi-
destination, is encouraged. Product quality can be affected
tion of the larger quantity.
through careless handling, improper protection, and delayed
3.14 sample division—the process whereby a sample is
shipment. It is preferable to sample at the point of loading.The
reduced in weight without change in particle size.
consumer has the right to witness the sampling practices being
used.
3.15 sample preparation—the process that may include
crushing, dividing, and mixing of a gross or divided sample for
4.5 This practice may be used to provide a representative
the purpose of obtaining a representative analysis sample.
sample of lime or limestone products. Due to the variability of
3.16 sampling unit—a quantity of material from which a
limestone and lime and the wide variety of sampling
gross sample is obtained. A lot may contain several sampling equipment,cautionmustbeexercisedinallstagesofsampling,
units.
from system specification and equipment procurement to
2 equipment acceptance testing and actually taking the final
3.17 segregation variance of increment collection, Ss —the
sample.
variance caused by nonrandom distribution of inert material or
other constituent in the lot.
5. Incremental Collection
3.18 size consist—the particle size distribution of quicklime
5.1 For the number and weight of increments refer to
or hydrated lime.
Practice E122.
3.19 standard deviation—the square root of the variance.
5.2 The number of samples required depends on the in-
3.20 subsample—a sample taken from another sample.
tended use of the material, the quantity of material involved,
3.21 top size—the opening of the smallest screen in the
and the variations both in quality and size.Asufficient number
series upon which is retained less than 5 % of the sample.
of samples shall be obtained to cover all variations in the
material.
3.22 totalvariance,So —theoverallvarianceresultingfrom
collecting single increments, and including division and analy-
5.3 The quantity of sample to be taken will depend on the
sis of the single increments.
size of the material to be sampled and the amount of informa-
3.23 unbiased sample—a sample free of bias or a represen-
tion to be obtained from the sample. Caution must be taken to
tative sample.
ensure a statistically correct amount of material is selected for
all testing, and sufficient quantities of material retained for
3.24 unit variance (random variance of increment
reserved purposes. Recommended reference documents would
collection), Sr —the theoretical variance calculated for a uni-
include Practices E105 and E122.
formly mixed lot and extrapolate to 0.5-kg [1-lb] increment
size.
5.4 Particle Size:
3.25 variance—the mean square of deviation (or errors) of a 5.4.1 Generally, a large range of particle sizes for a given
setofobservations;thesumofsquareddeviations(orerrors)of material requires a larger bulk sample size. The amount of the
individual observations with respect to their arithmetic mean sample increment is then dependent upon the largest particle
C50/C50M − 13 (2019)
size encountered. The sample amount is determined by re- 7.3 Preservation of Sample:
peated testing to determine the bias between successive 7.3.1 Due to the hygroscopic nature of quicklime, samples
increments, and then to reduce this bias to acceptable limits. must be immediately stored in airtight, moisture-proof contain-
5.4.2 Thechemistrymaychangerelativetotheparticlesize. ers to avoid air-slaking and subsequent absorption of carbon
It is important that all particle sizes proportioned relative to dioxide.
their distribution be in the parent material. 7.3.2 Due to the generally soft characteristics of quicklime,
proper handling to avoid degradation must be practiced if the
5.5 Large material transfer rates result in large incremental
sample is to be used for particle size determination.
samples. The sample must be representative of the entire
cross-section flow of material. The amount of sample and 7.4 LocationofSampling—Theprocesstypeandtheprocess
number of increments must be determined prior to sampling. measurements required determine the sampling location. Sites
Randomized sampling should be used where appropriate to should be selected to allow for safe, easy access to a represen-
minimize unintentional bias. tative cross section of the process material.
7.5 ChoiceofSamplingProcedure—Thechoiceofsampling
6. Random Sampling
procedure to be used is dependent on three things. First, it is
6.1 Practices D3665, E105, and E122 can be used to
necessary to define the lot or batch of material to be sampled.
minimize unintentional bias when obtaining a representative
Second, it is necessary to determine the number of incremental
sample. Depending upon what comprises the lot of material,
samples to be taken from the lot. Third, the choice of sampling
sampling can be extended to specific shipping units chosen on
procedure needs to be determined from Section 8 utilizing the
a random basis.
preceding criteria.
6.2 Collect increments with such frequency that the entire
7.6 Recommended Number and Weight of Increments:
quantity of material will be represented in the gross sample.
7.6.1 Refer to Table 1 for the recommended number and
Due to the variability of lime and limestone products and the
weight of increments for general purpose sampling. The
wide variety of sampling equipment, caution must exercised in
number of increments required listed in Table 1 are based upon
all stages of sampling.
a 1000–tonne [1000 ton] lot size. To determine the number of
increments recommended for a specific lot size, use Eq 1.To
7. Sampling Plan
determine the recommended weight for a bulk sample, multi-
7.1 Purpose:
ply the increment requirement times the minimum increment
7.1.1 Adequate methods for obtaining representative
weight from Table 1. The nominal particle size is assigned
samples for testing the chemical and physical properties of a
based on production screening.
shipment of lime or limestone are essential. The sale and use
7.6.2 The increments and weights listed in Table 1 are only
are dependent upon the chemical or physical properties, or
recommendations and are not based upon a statistical model.
both.
For more accurate methods to determine weights and incre-
7.1.2 The sampling plan specifies the minimum weights and
ments required, refer to Practices E105, E122, and E141 and
the number of increments required in each step of the proce-
Practice D2234/D2234M.
dure to meet the objectives of the testing.
7.6.3 For randomized sampling, refer to Practice D3665.
7.1.3 The sampling plan should include the personnel doing
1/2
N 5N @specific lot size ~tonnes @ton#!/1000 tonnes@tons## (1)
the sampling, preservation or protection of the samples, loca-
2 1
tion of sampling, the sampling procedure to be used, sample
where:
preparation required, and the tests to be performed.
N = minimum increments required, per 1000 tonne [1000
7.1.4 Proper sampling involves understanding and consid-
ton] lot, and
eration of the minimum number and weight of increments, the
N = increments required for specified lot size rounded to
particle size of the material, sample preparation, variability of
the nearest whole number.
the constituent sought, and the degree of precision required.
7.7 Mechanical Sampling Devices—There are several dif-
7.2 Personnel:
ferent types of mechanical sampling devices available for
7.2.1 Itisimperativethatasampleiscollectedcarefullyand
many of the sampling procedures mentioned in Section 8. Due
conscientiously. If the sampling is done improperly, the sample
to the variety of types, it is impractical to specifically identify
is in error and any subsequent analysis is not representative of
each device. Prior to using any mechanical sampling device, it
the lot being sampled. Further, a second sample may be
needs to be determined that the device is capable of taking an
impossible to obtain. If an analysis is in error, another analysis
unbiased, representative sample of the material in question.
is impractical on an incorrectly obtained sample. Whereas, a
second analysis is possible, if the first was in error, if the initial
sampling was correct.
TABLE 1 Recommended Number and Mass of Increments for
7.2.2 Because of the importance of proper sampling and the
General Purpose Sampling
resulting information, individuals engaged in sampling and
Nominal Particle Size −6.3 mm +6.3mmby19mm +19 mm
sample preparation must be qualified by training and experi- [–1/4 in.] [+1/4 by −3/4 in.] [+3/4 in.]
Minimum number of increments 10 10 10
ence and possess a thorough understanding of sampling prac-
Minimum mass of increment, 2.5 [5] 5 [10] 7.5 [15]
tices and techniques or under the direct supervision of such an
kg [lb]
individual.
C50/C50M − 13 (2019)
8. Sampling Procedures (See Sampling Procedure Flow 8.1.1 Surface sampling is limited in use due to the nonrep-
Chart (Fig. 1) for Location of Specific Methods) resentative sample obtained. For exploration purposes, a sur-
face sample can produce information with respect to the
LIMESTONE
characteristics of a deposit. It is critical to remember that a
8.1 Surface Sampling:
FIG. 1 Sampling Procedures Flow Chart
C50/C50M − 13 (2019)
surface sample is not representative and can only be used to the preceding process to remove the number of increments
determine if more detailed sampling and testing may be necessary to compose the bulk sample.
justified.
8.4.1.2 Head-Pulley Sample:
8.1.2 Obtain the necessary information to determine a
(1) When looking at a granular or pebble material con-
suitable location for sampling. Choose sites that will best veyed with a belt, the fines tend to sift though the coarser
satisfy the purpose of sampling. Describe and record observa-
material and ride on the bottom and toward the middle of the
tions on the characteristics of the portion of the deposit being belt. The coarse and fines thus become segregated to an extent
sampled to the extent required by the sampling plan. It is
dependent upon gradation and physical conditions of the
imperative for the sample collected to be of sufficient size to material being sampled. As the material is projected from the
perform any required testing. head-pulley,thecoarsermaterialisthrownslightlyfurtherwith
the fines dropping closer to the head-pulley. The most impor-
8.2 Face Sampling—Describe and record observations on
tant considerations, therefore, in sampling at a head-pulley is
the characteristics of the portion of the face being sampled to
that the entire cross section of material flow (fines and coarse)
the extent required by the sampling plan. With suitable
is obtained with the pass of the sampling apparatus. And
marking equipment, identify the sampling site in accordance
further, that the movement of the sampling apparatus is
with the sampling plan. It is imperative for the sample
accomplished in a timely manner, so as to reduce any bias in
collected to be of sufficient size to perform any required
sampling from the lateral movement of the sampler.
testing.
(2) Head-pulley sampling can only be accomplished manu-
8.3 Drill Hole Samples—The type of drilling equipment
ally if the flow of material is at a minimum for safety reasons,
required will be determined by the sampling plan. Sample the otherwise an automatic sampler is recommended.
drill hole in intervals as specified in the sampling plan.
8.4.2 Stockpile Sampling:
8.3.1 Drill Cuttings:
8.4.2.1 Sampling from stockpiles, although occasionally
8.3.1.1 Drill cuttings are deposited on the surface by the
necessary, is not recommended, because of the difficulty in
drilling equipment. Many drills use compressed air to blow the
guaranteeing an unbiased sample. When sized material is
drill cuttings out of the drill hole. These cuttings collect on the stockpiled, segregation occurs, with coarser particles rolling to
surface in a circular mound surrounding the hole. Collect a
theoutsidebaseofthepileandfinerparticlessiftingtowardthe
crosscut representative sample of the drill cuttings, taking care center. It is very difficult to ensure representative samples, due
not to contaminate with surface material.
to the segregation, which usually occurs when material is
stockpiled, with the coarser particles rolling to the outside base
8.3.1.2 Recirculated drill cuttings are produced from an-
of the pile. When it is necessary to sample stockpiles, every
other type of drilling equipment using compressed air to blow
effortshouldbemadetoenlisttheservicesofpowerequipment
the drill cuttings through the hollow center of equipment drill
that is capable of exposing the material at various levels and
steelintoacollectionchamber.Emptythischamberatintervals
locations. Separate samples shall be taken from different areas
determined in the sampling plan.
of the stockpiles to represent the material in that portion. Test
8.3.2 Drill Core:
results of the individual samples will indicate the extent of
8.3.2.1 Some drilling equipment cuts and removes solid
segregation existing in the stockpiles.
cylindrical cores of material from a drill hole. Sample these
8.4.2.2 If it is necessary to sample stockpiles, numerous
drill cores at intervals determined in the sampling plan.
increments should be obtained from various points and com-
8.3.2.2 Drill cores are split as determined by the sampling
bined to create the bulk sample. The number of increments
plans. One portion of the split core is preserved intact,
must be sufficient to indicate the degree of variability existing
maintaining its orientation and order as it is removed from the
within the pile. This is of particular importance when testing
drill hole. These samples are invaluable for historical purposes
for material gradation.
and are often saved for the life of the quarry.
8.4.2.3 If power equipment is available, larger increments
8.4 Limestone Kiln Feed Sampling:
can be obtained and then combined to form a smaller stockpile
8.4.1 Belt Sampling—Two conditions exist from which
from which the bulk sample can be removed. The increments
samples can manually be obtained from a conveyor belt.
must be of a sufficient number and from various locations on
8.4.1.1 Stop-Belt Sample: the main stockpile to ensure formation of a representative and
(1) Before stopping, the conveyor must be loaded with a unbiased sampling stockpile. After mixing the smaller
constant flow of material in order to be sampled.The conveyor stockp
...