ASTM E2294-21

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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: E2294 − 03 (Reapproved 2013) E2294 − 21
Standard Practice for
Proof Silver Corrections in Metal Bearing Ores,
Concentrates, and Related Materials by Fire Assay
Gravimetry
This standard is issued under the fixed designation E2294; 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 practice covers the determination of fire assay correction for silver, utilizing proof silver, ores, concentrates, and related
metallurgical materials.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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. (See Test Methods E1335, Practices E50, Guide E882, and
ISO Guide 35: 1989.)ISO Guide 35: 2017.)
1.4 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:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E50 Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
E1335 Test Methods for Determination of Gold in Bullion by Fire Assay Cupellation Analysis
2.2 Other Documents:
ISO Guide 35: 1989ISO Guide 35: 2017 Certification of Reference Materials- General and Statistical PrinciplesReference
Materials — Guidance for Characterization and Assessment of Homogeneity and Stability
ISO 10378: 1994ISO 10378: 2016 Copper Sulfide Concentrates–Determination Copper, Lead and Zinc Sulfide Concentrates —
Determination of Gold and Silver Contents–Fire — Fire Assay Gravimetric and Flame Atomic Absorption Spectrometric
Method
This practice is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.
Current edition approved Nov. 1, 2013Oct. 1, 2021. Published December 2013October 2021. Originally approved in 2003. Last previous edition approved in 20082013
ε1
as E2294 – 03 (2008) .(2013). DOI: 10.1520/E2294-03R13.10.1520/E2294-21
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.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
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E2294 − 21
3. Terminology
3.1 Definitions—For definitions of terms used in this Practice,practice, refer to Terminology E135.
4. Summary of Practice
4.1 In the process of fire assay, silver losses occur. Proof silver is carried through the assay fusion and cupellation procedures to
determine losses that can provide the fire assay silver correction values (see Test Methods E1335, ISO 10378: 1994,
4 5
ISO 10378: 2016, Bugbee, and Smith ).
5. Significance and Use
5.1 This practice is primarily intended to be used for the correction of silver loss in the fire assay process. Silver assays are
determined by fire assay for the purpose of metallurgical exchange between seller and buyer.
5.2 It is assumed that all who use this practice will be trained analysts capable of performing skillfully and safely. It is expected
that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described
in Guide E882.
6. Apparatus
6.1 Analytical balance—Balance—Capable of weighing to 0.001 mg.
6.2 Assay furnace—Furnace—Capable of temperatures up to 1100 °C, accurate to 6 5 °C.
6.3 Hammer—Blacksmith type.
6.4 Hammering block—Block—Flat Steel plate.
7. Reagents and Materials
7.1 Purity of Re
...