ASTM E887-21

Standard Test Method for Silica in Refuse-Derived Fuel (RDF) and RDF Ash

ABSTRACT
This test method covers the determination of silica in refuse-derived fuel (RDF), RDF ash, fly ash, bottom ash, or slag. The test method is an acid dehydration gravimetric procedure and is independent of interferences. Silicon compounds shall be dissolved by alkali fusion and dehydrated with hydrochloric acid (HCl). Dehydration is completed by ignition, and the silica is volatilized as silicon tetrafluoride.
SCOPE
1.1 This test method covers the determination of silica in refuse-derived fuel (RDF), RDF ash, fly ash, bottom ash, or slag.  
1.2 The test method is an acid dehydration gravimetric procedure and is independent of interferences.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For hazard statement, see Section 7.  
1.5 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.

General Information

• Status: Published
• Publication Date: 30-Sep-2021
• ICS: 75.160.10 - Solid fuels
• Technical Committee: D34 - Waste Management
• Drafting Committee: D34.03 - Treatment, Recovery and Reuse

Relations

• Refers: ASTM D5681-23 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2023
• Refers: ASTM D5681-18 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2018
• Refers: ASTM D5681-17 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Sep-2017
• Refers: ASTM D5681-16a - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Nov-2016
• Refers: ASTM D5681-16 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Feb-2016
• Refers: ASTM D5681-13 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Feb-2013
• Refers: ASTM D5681-09 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Jul-2009
• Refers: ASTM D6044-96(2009) - Standard Guide for Representative Sampling for Management of Waste and Contaminated Media
• Effective Date: 01-Feb-2009
• Refers: ASTM D5681-08 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Sep-2008
• Refers: ASTM E791-08 - Standard Test Method for Calculating Refuse-Derived Fuel Analysis Data from As-Determined to Different Bases
• Effective Date: 01-Sep-2008
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D5681-98a(2004) - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Sep-2004
• Refers: ASTM D5681-98a(2004)e1 - Standard Terminology for Waste and Waste Management
• Effective Date: 01-Sep-2004
• Refers: ASTM D6044-96(2003) - Standard Guide for Representative Sampling for Management of Waste and Contaminated Media
• Effective Date: 10-Mar-2003
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM E887-21 is the internationally recognized standard that outlines the test method for determining silica content in refuse-derived fuel (RDF), RDF ash, fly ash, bottom ash, and slag. Developed by ASTM International, this standard is essential for laboratories and entities involved in waste management, renewable energy, and environmental compliance. The method uses an acid dehydration gravimetric process, which is designed to minimize analytical interferences and ensure accurate quantification of silica across varied sample matrices.

By conforming to ASTM E887-21, laboratories and operators can obtain consistent, reliable silica data, which is vital for evaluating fuel characteristics, ash management, and downstream environmental impacts.

Key Topics

• Silica Determination in Waste Materials: The standard encompasses RDF, RDF ash, fly ash, bottom ash, and slag-common byproducts of waste-to-energy processes.
• Gravimetric Acid Dehydration Procedure: The process involves alkali fusion to dissolve silicon compounds, followed by hydrochloric acid dehydration, ignition, and volatilization of silica as silicon tetrafluoride.
• Independence from Interferences: The test method is formulated to deliver silica measurements unaffected by common interfering substances found in waste materials.
• Sample Preparation and Handling: Detailed instructions for representative sampling, reduction of particle size, and sample ashing ensure the analytical sample accurately reflects the bulk material.
• Safety Considerations: The standard emphasizes the necessity of appropriate laboratory safety measures, including PPE and fume extraction, particularly due to the use of potentially hazardous reagents like hydrofluoric acid.

Applications

ASTM E887-21 supports a wide range of practical and industrial applications:

• Waste-to-Energy Facility Operations: Quantitative silica analysis in RDF and ash guides process optimization and helps mitigate equipment fouling from high-silica residues.
• Compliance Monitoring: Regulatory agencies and facility operators use this method to ensure conformance to environmental standards related to ash composition and disposal.
• Material Characterization in Research: Academic and industrial researchers apply this standard to study the behavior of silica during refuse combustion, contributing to advancements in waste management technologies.
• Quality Assurance in Ash Utilization: When ash is repurposed for construction or other uses, ASTM E887-21 provides essential data on silica content, supporting product quality and regulatory compliance.
• Baseline Assessment for Contaminated Sites: The method is applicable for evaluating silica in waste-influenced soils or residuals at remediation sites, enhancing site assessment protocols.

Related Standards

To facilitate comprehensive waste and residue analysis, consider integrating ASTM E887-21 with these related standards:

• ASTM D1193 - Specification for Reagent Water: Establishes water purity requirements for laboratory use.
• ASTM D5681 - Terminology for Waste and Waste Management: Provides standard terms and definitions for the industry.
• ASTM D6044 - Guide for Representative Sampling for Management of Waste and Contaminated Media: Offers guidance for obtaining representative samples, critical for accurate silica analysis.
• ASTM E791 - Test Method for Calculating Refuse-Derived Fuel Analysis Data: Assists in converting test results between different reporting bases.
• ASTM E829 - Practice for Preparing RDF Laboratory Samples: Details preparation guidelines to ensure analysis consistency.

Conclusion

Adhering to ASTM E887-21 ensures precise, reproducible determination of silica in RDF and ash-derived materials, supporting efficient waste-to-energy operations, environmental compliance, and research. By utilizing this standard alongside related ASTM methods, laboratories and industry operators can maintain high-quality data and operational excellence in waste management and analysis.

Standards Content (Sample)

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: E887 − 21
Standard Test Method for
Silica in Refuse-Derived Fuel (RDF) and RDF Ash
This standard is issued under the fixed designation E887; 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 3. Terminology
1.1 This test method covers the determination of silica in 3.1 For definitions of terms used in this test method, refer to
refuse-derived fuel (RDF), RDF ash, fly ash, bottom ash, or Terminology D5681.
slag.
4. Summary of Test Method
1.2 The test method is an acid dehydration gravimetric
4.1 Silicon compounds in RDF ash, fly ash, bottom ash, or
procedure and is independent of interferences.
slag are dissolved by alkali fusion and dehydrated with
1.3 The values stated in SI units are to be regarded as the
hydrochloricacid(HCl).Dehydrationiscompletedbyignition,
standard. The values given in parentheses are for information
and the silica is volatilized as silicon tetrafluoride.
only.
1.4 This standard does not purport to address all of the
5. Apparatus
safety concerns, if any, associated with its use. It is the
5.1 Analytical Balance, capable of weighing to 0.0001 g.
responsibility of the user of this standard to establish appro-
5.2 Muffle Furnace—The furnace shall have an operating
priate safety, health, and environmental practices and deter-
temperature up to 1200 °C.
mine the applicability of regulatory limitations prior to use.
For hazard statement, see Section 7.
5.3 Hot Plate, Microwave Digester, or Steam Bath.
1.5 This international standard was developed in accor-
5.4 Platinum Crucibles, 35 to 85-mL capacity.
dance with internationally recognized principles on standard-
5.5 Graphite Crucibles, 35 to 85-mL capacity.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5.6 Fused Quartz Dishes, 35 to 85-mL capacity.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
6. Reagents and Materials
6.1 Purity of Reagents—Reagent grade chemicals shall be
2. Referenced Documents
used in this test. Unless otherwise indicated, it is intended that
2.1 ASTM Standards:
all reagents shall conform to the specifications of the Commit-
D1193 Specification for Reagent Water
tee onAnalytical Reagents of theAmerican Chemical Society,
D5681 Terminology for Waste and Waste Management
where such specifications are available. Other grades may be
D6044 Guide for Representative Sampling for Management
used, provided it is first ascertained that the reagent is of
of Waste and Contaminated Media
sufficiently high purity to permit its use without lessening the
E791 Test Method for Calculating Refuse-Derived Fuel
accuracy of the determination.
Analysis Data from As-Determined to Different Bases
6.2 Purity of Water—Unless otherwise indicated, reference
E829 Practice for Preparing Refuse-Derived Fuel (RDF)
to water shall be understood to mean at least Type III reagent
Laboratory Samples for Analysis
water conforming to Specification D1193.
6.3 Sodium Carbonate (Na CO ), anhydrous powder.
2 3
6.4 Hydrochloric Acid (HCl), concentrated, sp gr 1.19.
This test method is under the jurisdiction of ASTM Committee D34 on Waste
Management and is the direct responsibility of Subcommittee D34.03 on Treatment,
Recovery and Reuse.
Current edition approved Oct. 1, 2021. Published October 2021. Originally
approved in 1982. Last previous edition approved in 2015 as E887 – 15. DOI: Reagent Chemicals, American Chemical Society Specifications, American
10.1520/E0887-21. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E887 − 21
6.5 Hydrochloric Acid (1+3)—Mix 1 volume of concen- 9.1.6 Spread the ash in a thin layer in the dish, and ignite in
trated HCl with 3 volumes of water. a stream of oxygen for 1 ⁄2 h at 800 to 850 °C (1470 to
1560 °F) to ensure complete and uniform oxidation of the ash.
6.6 Hydrochloric Acid (1+1)—Mix 1 volume of concen-
9.1.7 Cool the ash to room temperature in a desiccator.
trated HCl with 1 volume of water.
9.1.8 Weigh the dish and the ash.
6.7 Hydrochloric Acid (1 + 99)—Mix 1 volume of concen-
9.1.9 Calculate the percent ash as follows:
trated HCl with 99 volumes of water.
% Ash 5 C 2 A / B 2 A 3100 (1)
~ ! ~ !
6.8 Sulfuric Acid (1+1)—Mix 1 volume of concentrated
where:
sulfuric acid (H SO , sp gr 1.84) with 1 volume of water.
2 4
A = weight of fused quartz dish, g,
6.9 Hydrofluric Acid (HF), concentrated 48 to 51 %.
B = weight of fused quartz dish and sample, g, and
C = weight of fused quartz dish and ash, g.
7. Hazards
9.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, or Slag:
7.1 Due to the origins of RDF in municipal waste, precau-
9.2.1 Prepare the RDF ash, fly ash, bottom ash, or slag by
tions should be observed when conducting tests on samples.
grinding the sample in an agate mortar to a particle size to pass
Recommended safety practices include use of suitable gloves
a No. 200 (75-µm) sieve.
when handling RDF; wearing dust masks (NIOSH-approved
9.2.2 Weighaccurately6to10gofRDFash,flyash,bottom
type), especially while milling RDF samples; conducting tests
ash, or slag as prepared in 9.2.1 into a conditioned preweighed
under negative pressure hoods when possible; and washing
fused quartz dish.
hands upon completion of activity and before eating or
9.2.3 Spread out the analysis sample of the ash to be
smoking.
analyzed in a layer not over 6.4 mm ( ⁄4 in.) in depth.
9.2.4 Place the dish in the muffle furnace at a low tempera-
8. Sampling
ture (not greater than 100 °C), and gradually heat to redness at
NOTE 1—See Guide D6044.
such a rate as to avoid mechanical loss from too rapid
8.1 Refuse-Derived Fuel (RDF):
expulsion of volatile matter.
8.1.1 RDF products are frequently nonhomogeneous. For
9.2.5 Complete the conversion to ash at a temperature of
this reason, significant care should be exercised to obtain a
800 to 900 °C (1470 to 1659 °F).
representative laboratory sample from the RDF lot to be
9.2.6 Cool in a desiccator and stir the ash to ensure
characterized.
homogeneity of particle sizes. Be careful not to lose any ash
8.1.2 The sampling method for these procedures should be
from the dish during this stirring.
based on agreement between involved parties.
9.2.7 Spread the ash in a thin layer in the dish and ignite in
8.1.3 The laboratory sample must be air-dried and particle
a stream of oxygen for 1 ⁄2 h at 800 to 850 °C (1470 to
size reduced to pass a 0.5-mm screen for analysis. This
1560 °F) to ensure complete and uniform oxidation of the ash.
procedure must be performed carefully to preserve the sam-
9.2.8 Cool the ash to room temperature in a desiccator.
ple’s representative characteristics
...

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: E887 − 15 E887 − 21
Standard Test Method for
Silica in Refuse-Derived Fuel (RDF) and RDF Ash
This standard is issued under the fixed designation E887; 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 test method covers the determination of silica in refuse-derived fuel (RDF), RDF ash, fly ash, bottom ash, or slag.
1.2 The test method is an acid dehydration gravimetric procedure and is independent of interferences.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For hazard statement, see Section 67.
1.5 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:
D1193 Specification for Reagent Water
D5681 Terminology for Waste and Waste Management
D6044 Guide for Representative Sampling for Management of Waste and Contaminated Media
E791 Test Method for Calculating Refuse-Derived Fuel Analysis Data from As-Determined to Different Bases
E829 Practice for Preparing Refuse-Derived Fuel (RDF) Laboratory Samples for Analysis
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology D5681.
4. Summary of Test Method
4.1 Silicon compounds in RDF ash, fly ash, bottom ash, or slag are dissolved by alkali fusion and dehydrated with hydrochloric
acid (HCl). Dehydration is completed by ignition, and the silica is volatilized as silicon tetrafluoride.
This test method is under the jurisdiction of ASTM Committee D34 on Waste Management and is the direct responsibility of Subcommittee D34.03 on Treatment,
Recovery and Reuse.
Current edition approved Sept. 1, 2015Oct. 1, 2021. Published October 2015October 2021. Originally approved in 1982. Last previous edition approved in 20092015 as
E887 – 88 (2009).E887 – 15. DOI: 10.1520/E0887-15.10.1520/E0887-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E887 − 21
5. Apparatus
5.1 Analytical Balance, capable of weighing to 0.0001 g.
5.2 Muffle Furnace—The furnace shall have an operating temperature up to 1200°C.1200 °C.
5.3 Hot Plate, Microwave Digester, or Steam Bath.
5.4 Platinum Crucibles, 35 to 85-mL capacity.
5.5 Graphite Crucibles, 35 to 85-mL capacity.
5.6 Fused Quartz Dishes, 35 to 85-mL capacity.
6. Reagents and Materials
6.1 Purity of Reagents—Reagent grade chemicals shall be used in this test. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
6.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean at least Type III reagent water
conforming to Specification D1193.
6.3 Sodium Carbonate (Na CO ), anhydrous powder.
2 3
6.4 Hydrochloric Acid (HCl), concentrated, sp gr 1.19.
6.5 Hydrochloric Acid (1 + 3),(1 + 3)—Mix 1 volume of concentrated HCl with 3 volumes of water.
6.6 Hydrochloric Acid (1 + 1)—Mix 1 volume of concentrated HCl with 1 volume of water.
6.7 Hydrochloric Acid (1 + 99)—Mix 1 volume of concentrated HCl with 99 volumes of water.
6.8 Sulfuric Acid (1 + 1)—Mix 1 volume of concentrated sulfuric acid (H SO , sp gr 1.84) with 1 volume of water.
2 4
6.9 Hydrofluric Acid (HF), concentrated 48 to 51 %.
7. Hazards
7.1 Due to the origins of RDF in municipal waste, precautions should be observed when conducting tests on samples.
Recommended safety practices include use of suitable gloves when handling RDF; wearing dust masks (NIOSH-approved type),
especially while milling RDF samples; conducting tests under negative pressure hoods when possible; and washing hands upon
completion of activity and before eating or smoking.
8. Sampling
NOTE 1—See Guide D6044.
8.1 Refuse-Derived Fuel (RDF):
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
E887 − 21
NOTE 1—ASTM Subcommittee E38.01 is currently in the process of developing procedures for sampling RDF.
8.1.1 RDF products are frequently nonhomogeneous. For this reason, significant care should be exercised to obtain a
representative laboratory sample from the RDF lot to be characterized.
8.1.2 The sampling method for these procedures should be based on agreement between involved parties.
8.1.3 The laboratory sample must be air-dried and particle size reduced to pass a 0.5-mm screen for analysis. This procedure must
be performed carefully to preserve the sample’s representative characteristics (other than particle size) while preparing the analysis
sample to be used in this procedure (see Practice E829).
8.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, or Slag—The method of sampling for this procedure should be based on
agreement between involved parties.
9. Sample Preparation
9.1 Refuse-Derived Fuel:
9.1.1 Weigh accurately 30 to 50 g of RDF analysis sample as prepared in 6.17.1 into a conditioned and preweighed fused quartz
dish.
9.1.2 Spread out the analysis sample of RDF in a layer not over 38.1 mm (1 ⁄2 in.) in depth.
9.1.3 Place the dish in the muffle furnace at a low temperature (not greater than 100°C)100 °C) and gradually heat to redness at
such a rate as to avoid mechanical loss from too rapid expulsion of volatile matter.
9.1.4 Complete the conversion to ash at a temperature of 800 to 900°C900 °C (1470 to 1650°F).1650 °F).
9.1.5 Cool in a desiccator and stir the ash to ensure homogeneity of particle sizes. Be careful not to lose any ash from the dish
during this stirring.
9.1.6 Spread the ash in a thin layer in the dish, and ignite in a stream of oxygen for 1 ⁄2 h at 800 to 850°C850 °C (1470 to
1560°F)1560 °F) to ensure complete and uniform oxidation of the ash.
9.1.7 Cool the ash to room temperature in a desiccator.
9.1.8 Weigh the dish and the ash.
9.1.9 Calculate the percent ash as follows:
% Ash 5 ~C 2 A!/~B 2 A! 3100 (1)
where:
where:
A = weight of fused quartz, g,
A = weight of fused quartz dish, g,
B = weight of fused quartz dish and sample, g, and
C = weight of fused quartz dish and ash, g.
9.2 Refuse-Derived Fuel Ash, Fly Ash, Bottom Ash, or Slag:
9.2.1 Prepare the RDF ash, fly ash, bottom ash, or slag by grinding the sample in an agate mortar to a particle size to pass a No.
200 (75-μm) sieve.
9.2.2 Weigh accurately 6 to 10 g of RDF ash, fly ash, bottom ash, or slag as prepared in 8.2.19.2.1 into a conditioned preweighed
fused quartz dish.
...