SIST ISO 10378:2006

INTERNATIONAL ISO
STANDARD 10378
Second edition
2005-07-01
Copper, lead and zinc sulfide
concentrates — Determination of gold
and silver — Fire assay gravimetric and
flame atomic absorption spectrometric
method
Concentrés sulfurés de cuivre, de plomb et de zinc — Dosage de l'or et
de l'argent — Méthode gravimétrique par essai au feu et spectrométrie
d'absorption atomique dans la flamme

Reference number
©
ISO 2005
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ii © ISO 2005 – All rights reserved

Contents Page
Foreword. v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Principle. 2
3.1 Fusion . 2
3.2 Cupellation . 2
3.3 Parting. 2
3.4 Retreatment . 2
3.5 Correction for blank contamination. 2
4 Reagents. 2
5 Apparatus . 4
6 Sample . 5
6.1 Test sample . 5
6.2 Test portion . 5
7 Procedure . 5
7.1 Number of determinations . 5
7.2 Trial fusion. 5
7.3 Blank tests. 5
7.4 Charge preparation. 6
7.5 Primary fusion. 7
7.6 Cupellation . 7
7.7 Retreatment of residues. 8
7.8 Determination of gold in the primary bead . 8
7.9 Determination of gold and silver in secondary beads and blanks, and of silver in prills. 9
7.10 Determination of silver in the parting solution. 11
8 Expression of results . 11
8.1 Mass fraction of gold. 11
8.2 Mass fraction of silver. 12
9 Precision. 13
9.1 Expression of precision . 13
9.2 Method for obtaining the final result (see Annex H) . 14
9.3 Precision between laboratories. 15
9.4 Check of trueness. 17
9.4.1 General. 17
9.4.2 Type of certified reference material (CRM) or reference material (RM) . 17
10 Test report . 18
Annex A (normative) Procedure for the preparation and determination of the mass of a predried
test portion . 19
Annex B (normative) Trial fusion. 21
Annex C (normative) Blank determination . 22
Annex D (normative) Inquartation .23
Annex E (normative) Determination of vaporization loss of silver during the cupellation process . 24
Annex F (normative) Sulfuric acid - Parting . 25
Annex G (normative) Determination of impurities in parting solutions and washings. 27
Annex H (normative) Flowsheet of the procedure for the acceptance of analytical values for test
samples (see 9.2) . 31
Annex I (informative) Flowsheet of the method. 32
Annex J (informative) Roasting method. 33
Annex K (informative) Guide to the preparation of dilutions for the determination of silver in
parting solutions and residues. 34
Annex L (informative) Derivation of precision equations. 35
Bibliography . 52

iv © ISO 2005 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10378 was prepared by Technical Committee ISO/TC 183, Copper, lead, zinc and nickel ores and
concentrates.
This second edition cancels and replaces the first edition (ISO 10378:1994), which has been technically
revised.
Introduction
This International Standard describes a method for the determination of the mass fraction of gold and silver in
copper, lead and zinc sulfide concentrates. This International Standard was prepared to enable laboratories to
determine the mass fraction of gold and silver in suitable samples using instrumental methods.

vi © ISO 2005 – All rights reserved

INTERNATIONAL STANDARD ISO 10378:2005(E)

Copper, lead and zinc sulfide concentrates — Determination of
gold and silver — Fire assay gravimetric and flame atomic
absorption spectrometric method
WARNING — This International Standard may involve hazardous materials, operations and equipment.
It is the responsibility of the user of this International Standard to establish appropriate health and
safety practices and determine the applicability of regulatory limitations prior to use.
1 Scope
This International Standard specifies a fire assay gravimetric and flame atomic absorption spectrometric
method for the determination of the mass fraction of gold and silver in copper, lead and zinc sulfide
concentrates as follows:
 Copper concentrates:
The method is applicable to the determination of mass fractions of gold from 0,5 g/t to 300 g/t and of
mass fractions of silver from 25 g/t to 1 500 g/t in copper sulfide concentrates containing mass fractions of
copper from 15 % to 60 %.
 Lead concentrates
The method is applicable to the determination of mass fractions of gold from 0,1 g/t to 25 g/t and of mass
fractions of silver from 200 g/t to 3 500 g/t in lead sulfide concentrates containing mass fractions of lead
from 10 % to 80 %.
 Zinc concentrates
The method is applicable to the determination of mass fractions of gold from 0,1 g/t to 12 g/t and of mass
fractions of silver from 10 g/t to 800 g/t in zinc sulfide concentrates containing mass fractions of zinc up to
60 %.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 385-1:1984, Laboratory glassware — Burettes — Part 1: General requirements
ISO 648:1977, Laboratory glassware — One-mark pipettes
ISO 1042:1998, Laboratory glassware — One-mark volumetric flasks
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 4787:1984, Laboratory glassware — Volumetric glassware — Methods for use and testing of capacity
ISO 9599:1991, Copper, lead and zinc sulfide concentrates — Determination of hygroscopic moisture in the
analysis sample — Gravimetric method
3 Principle
Fire assaying for the determination of gold and silver comprises a series of steps to separate firstly the
precious metals from most of the associated metals, followed by separation of the gold from silver and other
metals preconcentrated into a precious-metal alloy.
The stages that comprise the determinations are described in 3.1 to 3.5 inclusive.
3.1 Fusion
The samples are fu
...