Quick Routine Acid Digestion of Iron and Copper Ores for ICP-OES or ICP-MS Analysis

In the mining industry there is a large demand for fast routine digestions for elemental analysis:

• in prospecting for new mining projects or in developing and maintaining existing mines, large numbers of mineral samples have to be analyzed quickly. These samples consist of ore and dead rock of varying ratio and are analyzed for geochemical lead elements to give the information to find or follow the geological formations that allow the most profitable mining operation.
• In process control, when the refining process needs to be closely controlled. A lot of different types of process samples have to be analyzed with short turnaround time to allow swift reaction to keep the process under optimum conditions. For refining the analytical task is more specific: yield of process steps, quality of separation steps with the smallest possible amount of energy or reagent input.

In the past, fusion methods for the digestion of minerals and specific acid dissolution methods in combination with specialized photometric and electrochemical methods were used in large scale routine laboratories. With the widespread use of ICP optical or mass spectrometry modern high-temperature acid digestion becomes more and more attractive:

• No additional dissolved solids from fusion reagents. This reduces burden on the ICP sample introduction system and torch.
• Avoiding solid reagents reduces the risk of contamination.
• Swift streamlined digestion process in closed vessel.

The method described in the following suits for the samples studied and will be a good starting point for samples with different composition that may require some modifications e.g. of the acid mixture.