ASTM E2296-03(2008)e1

Standard Practice for Silver Corrections in Metal Bearing Ores, Concentrates, and Related Metallurgical Materials by Fire Assay Slag Recycling and Cupel Proof Gravimetry

SIGNIFICANCE AND USE
This practice is primarily intended to be used for the correction of silver loss in the fire assay process. Silver contents are determined by fire assay for the purpose of metallurgical exchange between buyer and seller. 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 E 882.
SCOPE
1.1 This practice covers the silver loss correction, utilizing slag recycling and cupellation of proof silver during the fire assay of metal bearing 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 and health practices and determine the applicability of regulatory limitations prior to use. (See Practices E 50 and ISO 35:1989.)

General Information

• Status: Historical
• Publication Date: 14-Dec-2008
• ICS: 73.060.99 - Other metalliferous minerals
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.02 - Ores, Concentrates, and Related Metallurgical Materials

Relations

• Replaces: ASTM E2296-03 - Standard Practice for Silver Corrections in Metal Bearing Ores, Concentrates, and Related Metallurgical Materials by Fire Assay Slag Recycling and Cupel Proof Gravimetry
• Effective Date: 15-Dec-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
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Designation: E2296 − 03 (Reapproved2008)
Standard Practice for
Silver Corrections in Metal Bearing Ores, Concentrates, and
Related Metallurgical Materials by Fire Assay Slag Recycling
and Cupel Proof Gravimetry
This standard is issued under the fixed designation E2296; 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.
´ NOTE—Editorial changes were made throughout in December 2008.
1. Scope 2.2 ISO Documents:
ISO 35:1989 Certification of Reference Materials—General
1.1 This practice covers the silver loss correction, utilizing
and Statistical Principles
slag recycling and cupellation of proof silver during the fire
ISO 10378:1994 Copper Sulfide Concentrates—
assay of metal bearing ores, concentrates, and related metal-
Determination of Gold and Silver Contents—Fire Assay
lurgical materials.
Gravimetric and Atomic Absorption Spectrometric
1.2 The values stated in SI units are to be regarded as
Method
standard. No other units of measurement are included in this
3. Terminology
standard.
3.1 Definitions—For definitions of terms used in this
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the practice, refer to Terminology E135.
responsibility of the user of this standard to establish appro-
4. Summary of Practice
priate safety and health practices and determine the applica-
4.1 In the process of fire assay fusion, the slag is retained
bility of regulatory limitations prior to use. (See Practices E50
from the initial fusion and reprocessed through the fusion
and ISO 35:1989.)
procedure. The resulting lead button is combined with the
2. Referenced Documents
preliminary lead button during cupellation. Proof silver is
carried through the cupellation procedure to determine the
2.1 ASTM Standards:
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silver losses. (See ISO 10378:1994, Bugbee, and Smith .)
E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
5. Significance and Use
E50 Practices for Apparatus, Reagents, and Safety Consid-
5.1 This practice is primarily intended to be used for the
erations for Chemical Analysis of Metals, Ores, and
correction of silver loss in the fire assay process. Silver
Related Materials
contents are determined by fire assay for the purpose of
E135 Terminology Relating to Analytical Chemistry for
metallurgical exchange between buyer and seller. It is assumed
Metals, Ores, and Related Materials
that all who use this practice will be trained analysts capable of
E882 Guide for Accountability and Quality Control in the
performing skillfully and safely. It is expected that work will
Chemical Analysis Laboratory
be performed in a properly equipped laboratory under appro-
priate quality control practices such as those described in
This practice is under the jurisdiction of ASTM Committee E01 on Analytical
Guide E882.
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 Dec. 15, 2008. Published January 2009. Originally Available from International Organization for Standardization (ISO), 1, ch. de
approved in 2003. Last previous edition approved in 2003 as E2296 – 03. DOI: la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
10.1520/E2296-03R08E01. www.iso.ch.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or Bugbee, E. E., A Textbook of Fire Assaying, Third Ed., John Wiley and Sons,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Inc., Hoboken, NJ, 1946.
Standards volume information, refer to the standard’s Document Summary page on Smith, E. A., The Sampling and Assay of the Precious Metals, Second Ed.,
the ASTM website. Charles Griffin and Co., Ltd., 1947.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E2296 − 03 (2008)
TABLE 1 Slag Re-Fusion Flux
9.2 Collectthefireassayfusionslagfromtheoriginalfusion
litharge 55.4 g and place back into the original fire assay crucible.
sodium carbonate 9.3 g
9.3 Add 50 g of the slag re-fusion flux to the crucible. The
silica sand 9.4 g
potassium bitartrate 7.3 g
composition is shown in Table 1.
borax 18.7 g
9.4 Place crucible in the fire assay furnace. Raise the
temperature to 1060 °C. After the furnace obtains that
temperature, hold for at least 30 min. In most instances, the
6. Apparatus total furnace time will be approximately 1 h. Fusion must be in
a liquid state.
6.1 Assay Furnace, capable of temperatures up to 1100 °C,
accurate to 6 5 °C with draft controls.
NOTE 2—In most cases, the best way to add re-fusion flux is with a wax
paper bag. Place the re-fusion flux into the bag, twist the top, and place on
6.2 Analytical Balance, capable of weighing to 0.001 mg.
top of the original fu
...