Nickel assay is a method used to determine the concentration of nickel in a sample. This is a critical process in various fields, including metallurgy, environmental monitoring, and biomedical research, as nickel can be toxic in high concentrations. There are different techniques for nickel assay, including colorimetric, titrimetric, and electrochemical methods, each with its advantages and limitations. The choice of method depends on the nature of the sample and the required accuracy and precision. Nickel assay typically involves the use of complexing agents, reducing agents, and various indicators to produce a measurable signal that can be related to the nickel concentration in the sample. The results of nickel assay are often expressed in parts per million (ppm) or percentage (%). Overall, nickel assay is an essential analytical technique for assessing the quality and safety of materials and products and for understanding the impact of nickel on human health and the environment.

In the case of nickel concentrates, which are typically high-grade materials, the most common method used in trading is fire assay. This method involves heating the sample in a furnace with a flux, such as litharge or borax, to produce a button of nickel and other metals. The button is then weighed and dissolved in acid, and the resulting solution is analyzed for nickel content using atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectrometry (ICP-OES).

Fire assay is a widely accepted method for the determination of nickel content in concentrates because it is considered to be a reliable and accurate method, and it is widely used in the mining and metallurgical industries. In addition, fire assay is an established method that has been standardized by various international organizations, such as ISO and ASTM, which provides a level of consistency and comparability between different laboratories and traders.

Traders may also use other methods, such as wet chemistry or X-ray fluorescence, depending on the application and the level of accuracy and precision required. It is important to establish a clear and agreed-upon method for nickel assay in trading, to ensure transparency and fairness in the market.

Other methodologies implemented by Xertek:

Atomic Absorption Spectroscopy (AAS): AAS has a working range of 0.1 – 100 ppm, with a detection limit of 0.001 ppm. This method is commonly used for the determination of nickel in environmental samples, such as water and soil.

Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES): ICP-OES has a wider working range than AAS, typically between 0.01 – 100 ppm, with a detection limit of 0.001 ppm. It is commonly used for the determination of nickel in geological, metallurgical, and environmental samples.

Colorimetric Methods: Colorimetric methods have a working range of 0.05 – 5 ppm, with a detection limit of 0.001 ppm. These methods are commonly used for the determination of nickel in water, soil, and biological samples.

Titrimetric Methods: Titrimetric methods have a working range of 0.01 – 1% nickel, with a detection limit of 0.001%. These methods are commonly used for the determination of nickel in metallurgical and environmental samples.