ASTM E1915-13 - 1.4.2013
 
Significance and Use

4.1 These test methods are primarily intended to test materials for compliance with compositional specifications and for monitoring.

4.1.1 The determination of carbon and sulfur and acid neutralization potential in ores and related materials is necessary to classify ores for metallurgical processing and to classify waste materials from the mining and processing of ores such as leach residues, waste rock, and tailings according to their potential to generate acid in the environment. This information is useful during mine development to assist in mining and mineral processing operations and for proper disposal of waste materials.

4.1.1.1 The use of the acid neutralization potential titration low range method is most useful where acidity is present in the samples and when acid potential by titration is desired in the uncertain content range below 2 % CaCO3.

4.1.2 These test methods are also used to isolate minerals based on carbon and sulfur contents of metal-bearing ores and related materials so that acid-base accounting can be performed (that is, carbonate mineral acid neutralization potential (ANP) minus sulfide-sulfur mineral acid generation potential (AGP) = net calcium carbonate (NCC)).

4.1.3 Additionally, the carbon hydrochloric acid insoluble test method has utility to identify the amount of organic carbon contained in gold ores so that potential for preg robbing can be identified and rectified through established pretreatment methods prior to cyanidation. Warning—Pyrolysis pretreatment at 550 °C has a potential to thermally decompose some carbonate minerals: (1) transition metal carbonates (for example, siderite, FeCO3, and rhodochrosite, MnCO3) decompose, yielding carbon dioxide, CO2, in the range of 220 °C to 520 °C; (2) calcite decomposes slightly between 300 °C and 500 °C, although most decomposition occurs above 550 °C; (3) dolomite decomposes at 800 °C to 900 °C (Hammack, 1994, p. 440).3

4.2 These test methods also may be used for the classification of rock to be used in construction, where the potential to generate acid under environmental conditions exists.

4.3 It is assumed that the users of these test methods will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory and that proper waste disposal procedures will be followed. Appropriate quality control practices such as those described in Guide E882 must be followed.

 
1. Scope

1.1 These test methods cover the determination of total carbon and sulfur and acid-base characteristics in metal bearing ores and related materials such as leach residues, tailings, and waste rock within the following ranges:

Analyte

Application Range, %

Quantitative Range, %

Total Carbon

0 to 10

0.08 to 10

Total Sulfur

0 to 8.8

0.023 to 8.8


Note 1The test methods were tested over the following ranges:

Total Carbon

0.01 % to 5.87 %

Total Sulfur

0.0002 % to 4.70 %

Residual Carbon from Pyrolysis

0.002 % to 4.97 %

Residual Sulfur from Pyrolysis

0.014 % to 1.54 %

Pyrolysis Loss Sulfur

0 % to 4.42 %

Hydrochloric Acid Insoluble Carbon

0.025 % to 0.47 %

Hydrochloric Acid Loss Carbon

0 % to 5.78 %

Hydrochloric Acid Insoluble Sulfur

0.012 % to 4.20 %

Acid Neutralization Potential Acidity Titration

-1.0 % to 100 %

Acid Neutralization Potential Acidity Titration Low Range

-1.0 % to 2 % CaCO3

Nitric Acid Insoluble Sulfur

0.006 % to 0.924 %

Nitric Acid Loss Sulfur

-0.08 % to 4.19 %

Sodium Carbonate Insoluble Sulfur

0.007 % to 3.78 %


1.2 The quantitative ranges for the partial decomposition test methods are dependent on the mineralogy of the samples being tested. The user of these test methods is advised to conduct an interlaboratory study in accordance with Practice E1601 on the test methods selected for use at a particular mining site, in order to establish the quantitative ranges for these test methods on a site-specific basis.

1.3 The test methods appear in the following order:

 

Sections

Carbon and Sulfur, Total

10.1-10.9

Carbon and Sulfur, Residual from Pyrolysis

10.10-10.18

Carbon and Sulfur, Hydrochloric Acid Insoluble

10.19-10.27

Acid Neutralization Potential Acidity Titration

10.28-10.36

Acid Neutralization Potential Acidity Titration Low Range

10.37-10.46

Sulfur, Nitric Acid Insoluble

10.47-10.55

Sulfur, Sodium Carbonate Insoluble

10.56-10.64


1.4 The values stated in SI units are to be regarded as standard.

1.5 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. Specific warning statements are given in Section 6.

 
2. Referenced Documents

D5744-18

Standard Test Method for Laboratory Weathering of Solid Materials Using a Humidity Cell

D5673-16

Standard Test Method for Elements in Water by Inductively Coupled Plasma´Mass Spectrometry

D1976-20

Standard Test Method for Elements in Water by Inductively-Coupled Plasma Atomic Emission Spectroscopy

D1193-06(2018)

Standard Specification for Reagent Water

D1067-16

Standard Test Methods for Acidity or Alkalinity of Water

E2242-21

Standard Test Method for Column Percolation Extraction of Mine Rock by the Meteoric Water Mobility Procedure

D6234-13(2020)

Standard Test Method for Shake Extraction of Mining Waste by the Synthetic Precipitation Leaching Procedure

E29-22

Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

E882-10(2016)e1

Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory (Includes all amendments and changes 10/27/2017).

E135-23a

Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials (Includes all amendments and changes 7/17/2023).

E50-17

Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials

E1019-18

Standard Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Inert Gas Fusion Techniques

E1601-19

Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method

E1950-17

Standard Practice for Reporting Results from Methods of Chemical Analysis (Withdrawn 2023)