ASTM E2060-22

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: E2060 − 06 (Reapproved 2014) E2060 − 22
Standard Guide for
Use of Coal Combustion Products for Solidification/
Stabilization of Inorganic Wastes
This standard is issued under the fixed designation E2060; 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 guide covers methods for selection and application of coal combustion products (CCPs) for use in the chemical
stabilization of trace elements in wastes and wastewater. These elements include, but are not limited to, arsenic, barium, boron,
cadmium, chromium, cobalt, lead, molybdenum, nickel, selenium, vanadium, and zinc. Chemical stabilization may be
accompanied by solidification of the waste treated. Solidification is not a requirement for the stabilization of many trace elements,
but does offer advantages in waste handling and in reduced permeability of the stabilized waste.
1.1.1 Solidification is an important factor in treatment of wastes and especially wastewaters. Solidification/Stabilization (S/S)
technology is often used to treat wastes containing free liquids. This guide addresses the use of CCPs as a stabilizing agent (with
or without the addition of other materials; however, stabilization or chemical fixation may also materials. Stabilization may be
achieved by using combinations of CCPs and other products such as lime, lime kiln dust, cement kiln dust, cement, and others.
CCPs used alone or in combination with other reagents promote stabilization of many inorganic constituents through a variety of
mechanisms. These mechanisms include precipitation as hydrates, carbonates, silicates, sulfates, and so forth; microencapsulation
of the waste particles through pozzolanic reactions; formation of metal precipitates; and formation of hydrated phases (1-4).
Long-term performance of the stabilized waste is an issue that must be addressed in considering any S/S technology. In this guide,
several tests are recommended to aid in evaluating the long-term performance of the stabilized wastes.
1.2 The CCPs that are suited tofor this application include fly ash, spent dry scrubber sorbents, and certain advanced sulfur control
by-products from processes such as duct injection dry flue gas desulfurization (FGD) material, and and fluidized-bed combustion
(FBC).(FBC) ash.
1.3 The wastes or wastewater, or both, containing the problematic inorganic species will likely may be highly variable, so the
chemical characteristics of the waste or wastewater to be treated must be determined and considered in the selection and
application of any stabilizing agent, including CCPs. In any waste stabilization process, laboratory-scale tests for compatibility
between the candidate waste or wastewater for stabilization with one or more selected CCPs and final waste stability are
recommended prior to pilot-scale and full-scale application of the stabilizing agent.
1.4 This guide does not intend to recommend pilot-scale or full-scale processes or procedures for waste stabilization. Full-scale
processes should be designed and carried out by qualified scientists, engineers, and environmental professionals. It is recommended
that stabilized materials generated at the full-scale stabilization site be subjected to testing to verify laboratory test results.
This guide is under the jurisdiction of ASTM Committee E50 on Environmental Assessment, Risk Management and Corrective Action and is the direct responsibility
of Subcommittee E50.03 on Beneficial Use.
Current edition approved Dec. 1, 2014Nov. 1, 2022. Published February 2015December 2022. Originally approved in 2000. Last previous edition approved in 20062014
as F2060 – 06.F2060 – 06(2014). DOI: 10.1520/E2060-06R14.10.1520/E2060-22.
The boldface numbers in parentheses refer to the list of references at the end of the text.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2060 − 22
1.5 The utilization of CCPs under this guide is a component of a pollution prevention program; Guide program. E1609 describes
pollution prevention activities in more detail. Utilization of CCPs in this manner conserves land, natural resources, and energy.
1.6 This guide applies only to CCPs produced primarily from the combustion of coal. It does not apply to ash or other combustion
products derived from the burning of waste; coal coking byproducts; municipal, industrial, or commercial garbage; sewage sludge
or other refuse, or both; derived fuels; wood waste products; rice hulls; agricultural waste; or other noncoal fuels.
1.7 Regulations governing the use of CCPs vary by state. nation, state and locality. The user of this guide has the responsibility
to determine and comply with applicable regulations.
1.8 It is recommended that work performed under this guide be designed and carried out by qualified scientists, engineers, and
environmental professionals.
1.9 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.10 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.
2. Referenced Documents
2.1 ASTM Standards:
C114 Test Methods for Chemical Analysis of Hydraulic Cement
C311 Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete
C400 Test Methods for Quicklime and Hydrated Lime for Neutralization of Waste Acid
D75 Practice for Sampling Aggregates
D422 Test Method for Particle-Size Analysis of Soils (Withdrawn 2016)
D558 Test Methods for Moisture-Density (Unit Weight) Relations of Soil-Cement Mixtures
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D1556 Test Method for Density and Unit Weight of Soil in Place by Sand-Cone Method
D1633 Test Methods for Compressive Strength of Molded Soil-Cement Cylinders
D1635 Test Method for Flexural Strength of Soil-Cement Using Simple Beam with Third-Point Loading
D2166 Test Method for Unconfined Compressive Strength of Cohesive Soil
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D2922 Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth) (Withdrawn 2007)
D2937 Test Method for Density of Soil in Place by the Drive-Cylinder Method
D3441 Test Method for Mechanical Cone Penetration Testing of Soils
D3877 Test Methods for One-Dimensional Expansion, Shrinkage, and Uplift Pressure of Soil-Lime Mixtures (Withdrawn 2017)
D3987 Practice for Shake Extraction of Solid Waste with Water
D4318 Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
D4842D4832 Test Method for Determining the Resistance of Solid Wastes to Freezing and ThawingPreparation and Testing of
Controlled Low Strength Material (CLSM) Test Cylinders (Withdrawn 2006)
D4843 Test Method for Wetting and Drying Test of Solid Wastes
D4972 Test Methods for pH of Soils
D5084 Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall
Permeameter
D5239D5907 Practice for Characterizing Fly Ash for Use in Soil StabilizationTest Methods for Filterable Matter (Total
Dissolved Solids) and Nonfilterable Matter (Total Suspended Solids) in Water (Withdrawn 2021)
D6913 Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis
D6938 Test Methods for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)
E1609D7928 Guide for Development and Implementation of a Pollution Prevention ProgramTest Method for Particle-Size
Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis (Withdrawn 2010)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
E2060 − 22
E2201 Terminology for Coal Combustion Products
3. Terminology
3.1 Definitions:
3.1.1 Definitions are in accordance with Terminology D653E2201.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 advanced sulfur control (ASC) products— by-products generated from advanced coal conversion technologies including
FBC and gasification and by-products from advanced environmental emissions cleanup technologies such as duct injection and
lime injection multiphase burners (LIMB).
3.2.2 baghouse—a facility constructed at some coal-fired power plants consisting of fabric filter bags that mechanically trap
particulates (fly ash) carried in the flue gases.
3.2.3 beneficial use—projects promoting public health and environmental protection, offering equivalent success relative to other
alternatives, and preserving natural resources.
3.2.4 BDAT—best demonstrated available technology.
3.2.5 boiler slag—a molten ash collected at the base of slag tap and cyclone boilers that is quenched in a water-filled hopper and
shatters into black, angular particles having a smooth, glassy appearance.
3.2.1 bottom ash—BDAT—agglomerated ash particles formed in pulverized coal boilers that are too large to be carried in the flue
gases and impinge on the boiler walls or fall through open grates to an ash hopper at the bottom of the boiler. Bottom ash is
typically grey-to-black in color, is quite angular, and has a porous surface texture.best demonstrated available technology.
3.2.1.1 Discussion—
The treatment technology that best minimizes the mobility or toxicity (or both) of the hazardous constituents for a particular waste.
3.2.7 coal combustion products—fly ash, bottom ash, boiler ash, or flue gas desulfurization (FGD) material resulting from the
combustion of coal.
3.2.8 DSC—differential scanning calorimetry.
3.2.9 DTA—differential thermal analysis.
3.2.10 DTG—differential thermal gravimetry.
3.2.11 electrostatic precipitator—a facility constructed at some coal-fired power plants to remove particulate matter (fly ash) from
the flue gas by producing an electric charge on the particles to be collected and then propelling the charged particles by electrostatic
forces to collecting curtains.
3.2.12 encapsulation—complete coating or enclosure of a toxic particle by an additive so as to sequester that particle from any
environmental receptors that may otherwise have been negatively impacted by that particle.
3.2.2 ettringite—a mineral with the nominal composition Ca Al (SO ) (OH) · 26H O. Ettringite is also the family name for a
6 2 4 3 12 2
series of related compounds, known as a mineral group or family, which includes the following minerals O (1):
Ettringite Ca Al (SO ) (OH) · 26H O
6 2 4 3 12 2
Charlesite Ca (Si,Al) (SO ) (B[OH] )(OH) · 26H O
6 2 4 2 4 12 2
Sturmanite Ca Fe (SO ) (B[OH] )(OH) · 26H O
6 2 4 2 4 12 2
Thaumasite Ca Si (SO ) (CO ) (OH) · 24H O
6 2 4 2 3 2 12 2
Jouravskite Ca Mn (SO ) (CO ) (OH) · 24H O
6 2 4 2 3 2 12 2
Bentorite Ca (Cr,Al) (SO ) (OH) · 26H O
6 2 4 3 12 2
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3.2.14 flue gas desulfurization material—a by-product of the removal of the sulfur gases from the flue gases, typically using a
high-calcium sorbent such as lime or limestone. Sodium-based sorbents are also used in some systems. The three primary types
of FGD processes commonly used by utilities are wet scrubbers, dry scrubbers, and sorbent injection. The physical nature of these
by-products varies from a wet, thixotropic sludge to a dry powdered material, depending on the process.
3.2.15 fly ash—coal ash that exits a combustion chamber in the flue gas. Coal fly ashes are typically pozzolans. Some coal fly ashes
also exhibit self-hardening properties in the presence of moisture.
3.2.16 pozzolans—siliceous or siliceous and aluminous materials that in themselves possess little or no cementitious value but will,
in finely divided form and in the presence of moisture, chemically react with calcium hydroxides at ordinary temperatures to form
compounds possessing cementitious properties.
3.2.3 S/S—solidification/stabilization.
3.2.18 stabilization or fixation—immobilization of undesirable constituents to limit their introduction into the environment. Toxic
components are immobilized by treating them chemically to form insoluble compounds.
3.2.19 solidification—the conversion of soils, liquids, or sludges into a solid, structurally sound material for disposal or use,
typically referring to attainment of 50 psi or strength of surrounding soil.
3.2.4 XRD—x-ray diffraction.
4. Significance and Use
4.1 General—CCPs can have chemical and mineralogical compositions that are conducive to use in the chemical stabilization of
trace elements in wastes and wastewater. These elements include, but are not limited to, arsenic, barium, boron, cadmium,
chromium, cobalt, lead, molybdenum, nickel, selenium, vanadium, and zinc. Chemical stabilization may be accompanied by
solidification of the waste treated. Solidification is not a requirement for the stabilization of many trace elements, but does offer
advantages in waste handling and in reduced permeability of the stabilized waste. This guide addresses the use of CCPs as a
stabilizing agent with or without addition of other materials. S/S
NOTE 1—In the United States, S/S is considered the BDAT for the disposal of some wastes that contain metals since they cannot be destroyed by other
means (2). is considered the BDAT for the disposal of some wastes that contain metals since they cannot be destroyed by other means
(2).
4.1.1 Advantages of Using CCPs—Advantages of using CCPs for waste stabilization include their ready availability in high
volumes, and generally good product consistency from one source, and easy handling. CCPs a single source. In addition, in some
instances certain CCPs can partly or entirely replace other expensive stabilization materials such as Portland cement. CCPs vary
depending on the combustion or emission control process and the coal or sorbents used, or both, and CCPs contain trace elements,
although usually at very low concentrations. CCPs are generally an environmentally suitable materials option for waste
stabilization, but the compatibility of a specific CCP must be evaluated with individual wastes or wastewater through
laboratory-scale tests followed by full-scale demonstration and field verification. CCPs suitable for thisthe chemical stabilization
have the ability to incorporate large amounts of free water into hydration products. via hydration reactions. These same hydration
reactions frequently result in the formation of mineral phases that stabilize or chemically immobilize the trace elements of concern.
CCPs that exhibit high pHs (>11.5) offer advantages in stabilizing trace elements that exist as oxyanions in nature (such as arsenic,
boron, chromium, molybdenum, selenium, and vanadium) and trace elements that form oxyhydroxides oxyhydroxides, carbonates
or other low-solubility precipitates at high pH (such as lead, cadmium, barium, and zinc). Additionally, CCPs that exhibit
cementitious properties offer advantages in solidifying CCP-waste mixtures as a result of the hydration reactions of the CCP. These
same hydration reactions frequently result in the formation of mineral phases that stabilize or chemically fix the trace elements of
concern.nickel, and zinc).
4.2 Chemical/Mineralogical Composition—Since many CCPs are produced under conditions of high generated at higher
temperature, reactions with water during contact with water or aqueous solutions can be expected. Mineral formation may
contribute to the chemical fixationstabilization and/or solidification achieved in the waste stabilizationtreatment process. One
example of this type of chemical fixationstabilization is achieved by ettringite formation. Reduced leachability of several trace
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elements has been correlated with ettringite formation in hydrated high-calcium CCPs typically from U.S. lignite and
subbituminous coal, FGD materials, and ASC by-products. These materials are the best general and dry FGD materials. These
materials worthy candidates for use in this chemical fixationstabilization process. Lower-calcium CCPs in presence of sulfate
sources, may also be effective with the addition of a calcium source that maintains the pH above 11.5. Ettringite forms as a result
of hydration of many high-calcium CCPs, CCPs in presence of sulfate sources, so adequate water must be available for the reaction
to occur. The mineral and amorphous phases of CCPs contribute soluble elements required for ettringite formation, and the
ettringite formation rate can vary based on the mineral and amorphous phase compositions.
4.3 Environmental Considerations:Regulatory Framework:
4.3.1 Regulatory Framework: Waste Management Framework—
4.3.1.1 Federal—In 1999, EPA completed a two-phased study of CCPs for the U.S. Congress as required by the Bevill Amendment
to RCRA. At the conclusion of the first phase in 1993, EPA issued a formal regulatory determination that the characteristics and
management of the four large-volume fossil fuel combustion wastestreams (that is, fly ash, bottom ash, boiler slag, and flue gas
emission control waste) do not warrant hazardous waste regulation under RCRA and that utilization practices for CCPs appear to
be safe. In addition, EPA “encourage[d] the utilization of coal combustion byproducts and support[ed] State efforts to promote
utilization in an environmentally beneficial manner.” In the second phase of the study, EPA focused on the byproducts generated
from FBC boiler units and the use of CCPs from FBC and conventional boiler units for mine reclamation, among other things.
Following completion of the study, EPA issued a regulatory determination in April 2000 that again concluded that hazardous waste
regulation of these combustion residues was not warranted. There is currently no regulatory program at the federal level that
addresses the utilization of CCPs. The wastes or wastewater requiring stabilization may fall under federal jurisdiction, so the final
stabilized material may need to be evaluated and disposed of according to federal regulations. Potentially applicable federal
regulations may include the Resource Conservation and Recovery Act (RCRA), Hazardous Solid Waste Act (HSWA),
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and Superfund Amendment and
Reauthorization Act (SARA). A brief description of these regulations is included in the EPA document, entitled Stabilization/
Solidification of CERCLA and RCRA Wastes: Physical Tests, Chemical Testing Procedures, Technology Screening, and Field
Activities(2) and have been summarized by ACAA (5). The EPA document states “stabilization/solidification is a proven
technology for the treatment of hazardous wastes and hazardous waste sites.” According to EPA (2), stabilization/solidification is
the BDAT for the disposal of some metals since they cannot be destroyed by other means. Provisions in federal laws list
requirements that land disposal of hazardous wastes is only acceptable if these wastes are treated with the BDAT or with
technology that meets or exceeds the treatment level of BDAT. Wastes that contain free liquids are prohibited from land disposal
by federal RCRA regulations or by equivalent state regulations, or both. The chemical binding of free liquids brought about by
solidification allows wastes that fail the EPA Paint Filter Test (EPA Method 9095-SW846) (6) to be land-disposed after successful
S/S treatment. Waste stabilization activities most often occur within a regulatory waste management framework. This regulatory
framework will generally establish minimum waste sampling and characterization requirements as well as establish documentation,
qualification, and performance criteria for waste management activities. The framework may also prescribe or prohibit certain
waste management practices. The applicable requirements of the regulatory framework may be formalized in a permit. This guide
is intended to be applied within the context of a regulatory waste management framework.
4.3.1.2 A summary of coal fly ash utilization in waste stabilization/solidification, including a discussion of environmental/
regulatory issues, demonstrations, and commercial applications, has been prepared (5).
NOTE 2—The U. S. regulatory framework is briefly described in Stabilization/Solidification of CERCLA and RCRA Wastes: Physical Tests, Chemical
Testing Procedures, Technology Screening, and Field Activities (2).
4.3.1.3 State—Some states do not have specific regulations addressing the use of CCPs, and requests for CCP use are handled on
a case-by-case basis or under generic state recycling laws or regulations. Some states have adopted laws and regulations or issued
policies and/or guidance regarding CCP use, but CCP use varies widely within these states (7). Waste or wastewater requiring
stabilization and the final stabilized material may also be regulated by individual states, so these regulations need to be identified
and followed. Many states are authorized to manage the hazardous waste management programs within their state. RCRA and
HSWA statutes allowed the states to become authorized by EPA. It is therefore extremely likely that S/S-treated waste will be
regulated by a state.
4.3.2 Beneficial Use Framework—Beneficial use activities often occur within a regulatory framework. In some locations, new
beneficial uses require prior regulatory approval as part of a beneficial use determination. Beneficial use determinations may
require specific characterization of the material and the beneficial use. Jurisdictions that require approval of beneficial use may also
maintain exemptions or predeterminations for certain materials or beneficial uses.
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5. CCP Characterization
5.1 General—Characterization of the CCP(s) under consideration for use as a stabilizing agent is needed to determine bulk
chemical and mineralogical composition to form ettringite when hydrated and that sufficient alkalinity is available to maintain a
high pH.
5.1 Sampling and Handling—General—Characterization of the CCP(s) under consideration for use as a stabilizing agent is
requiredd to determine bulk chemical and mineralogical composition. Sampling CCPs for testing purposes should conform to
Practice D75 or Test Method C311 as appropriate. Proper laboratory protocols for handling fine material should be followed.
5.2 Chemical Composition—Test Method C311 is often used to determine the major chemical constituents of CCP samples. The
most critical constituents requiring quantitation are calcium, aluminum, and sulfur.
5.3 pH—Test Method D4972 or PracticeU. S. D5239 may Environmental Protection Agency (USEPA) Method SW-9045 (5) can
be used to determine CCP pH. In assessing the test results, consideration should be given to the possibility that the pH of the CCP
may differ with age, water content, and other conditions. EPA Method SW-9045 . (8) is also applicable.
5.4 Buffer Capacity—The buffer capacityTest Method C400 of the CCP is important in maintaining the high pH that generally is
a requirement for the stabilization mechanisms of interest when CCPs are used as stabilization agents. The CCP must have enough
buffer capacity to maintain the pH of the stabilized waste in the appropriate range so the waste remains stable over time and under
environmental stresses. Test Methodcan be applied to evaluate the buffer capacity of the CCP, and to determine the basicity factor
for the CCP. It is important that the buffer capacity of the CCP is sufficient to maintain a high pH so that conditions are favorable
to allow the stabilization mechanisms of interest to occur (for eample, hydroxide formation, precipitation, etc.), and so that C400
can be applied to evaluate the buffer capacity of the CCP. Determine the basicity factor for the CCP as noted in Test Method B
of Test Method the waste remains stable over time and under environmental stresses.C400.
5.5 Swelling—Test Method D3877 can be used to determine the swelling potential of self-hardening (high-calcium) CCPs and
FGD material. The reactions producing the expansive properties generally do not commence for a period of more than begin to
occur until at least 30 days after initial CCP hydration. The test procedureTo address this delayed reaction the test method must
address this delayed reaction. The procedure should be modified to extend the wetting and drying cycle to 60 days. Expansive
reactions, including the formation of ettringite, may have an impact on the permeability of the stabilized waste. Following
completion
...