ASTM C911-19

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C911 − 06 (Reapproved 2011) C911 − 19
Standard Specification for
Quicklime, Hydrated Lime, and Limestone for Selected
Chemical and Industrial Uses
This standard is issued under the fixed designation C911; 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.
1. Scope*
1.1 This specification covers lime and limestone products suitable for the following chemical and industrial uses:
Cooking rags
Sulfite pulp
Silica brick
Other water treatment uses
Calcium carbide
Grease
Calcium silicate products
Hypochlorite (bleach)
The following uses are addressed in other ASTM standards:
Use Standard(s)
Neutralization of Waste Acid (Test C400
Methods)
Agricultural Liming Materials C602
Soil Stabilization C977
Asphalt C1097
Flue Gas Desulfurization (Test Meth- C1318
ods)
Drinking Water Softening C1529
Waste and Wastewater Neutralization C1529
Wastewater Treatment Plant Residuals C1529 and D6249
(Biosolids) Stabilization
1.2 The type designations in Table 1 signify the following:
Limestone, high-calcium—CL
Limestone, dolomitic—DL
Limestone, magnesian—ML
Quicklime, high-calcium—CQ
Quicklime, dolomitic—DQ
Quicklime, magnesian—MQ
Hydrated lime, high-calcium—CH
Hydrated lime, dolomitic—DH
Hydrated lime, magnesian—MH
1.3 The buyer shall designate the use, as listed in Table 1, and may specify one or more of the type designations in 1.1.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
This specification is under the jurisdiction of ASTM Committee C07 on Lime and Limestone and is the direct responsibility of Subcommittee C07.02 on Specifications
and Guidelines.
Current edition approved June 1, 2011May 1, 2019. Published July 2011May 2019. Originally approved in 1979. Last previous edition approved in 20062011 as
C911 – 06.C911 – 06 (2011). DOI: 10.1520/C0911-06R11.10.1520/C0911-19.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C911 − 19
2. Referenced Documents
2.1 ASTM Standards:
C25 Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated Lime
C50 Practice for Sampling, Sample Preparation, Packaging, and Marking of Lime and Limestone Products
C110 Test Methods for Physical Testing of Quicklime, Hydrated Lime, and Limestone
C400 Test Methods for Quicklime and Hydrated Lime for Neutralization of Waste Acid
C602 Specification for Agricultural Liming Materials
C977 Specification for Quicklime and Hydrated Lime for Soil Stabilization
C1097 Specification for Hydrated Lime for Use in Asphalt Cement or Bituminous Paving Mixtures
C1318 Test Method for Determination of Total Neutralizing Capability and Dissolved Calcium and Magnesium Oxide in Lime
for Flue Gas Desulfurization (FGD)
C1529 Specification for Quicklime, Hydrated Lime, and Limestone for Environmental Uses
D6249 Guide for Alkaline Stabilization of Wastewater Treatment Plant Residuals
3. Chemical Composition
3.1 The requirements for quicklime, hydrated lime, and limestone for the selected end uses are as shown in Table 1, and are
on the basis of the weight of sample taken at the place of manufacture, except as noted in footnote B after the requirement. In this
case, the requirement is on a moisture and carbon dioxide-free basis.
NOTE 1—Rags are cooked for the manufacture of paper in a digester under steam pressure with lime or with lime and soda ash. They are then washed
to eliminate as much of the noncellulose material as possible. A standard composition without rejection limits is specified for the reason that lime of either
higher or lower total oxides, available lime, calcium oxide, or calcium hydroxide than the standard, may safely be used under suitable conditions for the
purpose herein specified, depending primarily upon economic considerations. In the present state of the art, it is believed that the more serviceable type
of specification for the product herein specified is that which defines a reasonable standard rather than one that fixes actual rejection limits. It is generally
recognized that, other things being equal, lime meeting this standard is preferable to lime that does not, and lime surpassing the standard should be
considered of premium quality.
NOTE 2—Lime is used in the “milk of lime” or “tank” system of sulfite pulp manufacture for making the cooking liquor. The milk of lime is held in
solution or suspension in a series of tanks equipped with suitable agitators. The sulfur dioxide (SO ) is forced or drawn through these tanks successively.
In some cases, the tanks are built on top of each other in the form of a tower. The contents of the first tank are drawn off when the liquor has reached
a certain strength (3.5 to 6 % total SO ) and the contents of the second and third tanks progress to the first and second tanks respectively. The third tank
is again charged with fresh milk of lime. There are other systems of absorption that provide for continuous instead of intermittent operation. The function
of the lime is to furnish the base for the formation of the bisulfites of calcium and magnesium.
NOTE 3—In the manufacture of silica brick, silica in the form of massive quartzite or quartz conglomerate is ground until the particles are less than
⁄4 in. (6 mm) 6 mm in size. Lime in the form of either slaked or hydrated lime is then added in quantities varying from 1.5 to 3.0 % calcium oxide (CaO),
with sufficient water to produce about 5 to 7 % moisture content, and the shapes are molded and dried. They are then burned in downdraft or tunnel kilns
until most of the quartzite has been converted into tridymite or cristobalite.
NOTE 4—For most water treatment applications, such as color removal and clarification of water for municipal and industrial supplies, high-calcium
lime is preferred. However, for applications involving silica removal from boiler feedwater, dolomitic lime is usually preferred. Drinking water softening
and wastewater neutralization are addressed in Specification C1529.
NOTE 5—In manufacture of calcium hypochlorite bleach, hydrated lime hydrate in a water suspension is reacted with chlorine. Lime hydrateHydrated
lime suitable for this application should be rapidly reactive, low in sludge-forming impurities, and particularly low in iron oxide, that may catalyze bleach
decomposition.
4. General Requirements
4.1 Quicklime shall be reasonably free of unslakable residues and shall be capable of disintegrating in water to form a
suspension of finely divided material.
5. Sampling and Inspection
5.1 Conduct the sampling,
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