Generally Assay divided into 2 major parts, namely Wet Assay and Fire Assay. The large number of mining operations and analytical labs using the Fire Assay method to analyze metal content, especially gold, is one of the reasons why Fire Assay is a very interesting topic to discuss. Assay definition itself can find in the link, while we will focus to learn fire assay definition in this article.
The historical side of the fire assay will be a separate part due to the length of the discussion. A unique one being as written by Haffty et. Al, 1977, fire assay becomes the connotation of honesty and purity in the Old Testament Scriptures, regardless of what religion we believe. The historical side needs to be discussed because this method is one of the oldest methods of quantitative chemical analysis in the world. The method has not changed much in terms of reacting principles and reagents used. Major changes over time only in terms of the purity of the reagents. The another major change is the instruments used for the final analysis. One that gives a significant change to the Fire Assay method is the discovery of AAS.
Fire Assay definition
Fire assay definition is mostly define as one from many analytical method to analyse content of metals in sample by using heat or high temperature. For the example, gold fire assay need at least 1100 degree Celcius. The heat source can be from diesel burn or electrical heating element. All depends on the furnace type. Generally there are two types of furnace. First electrical furnace and second the diesel furnace. Divide by how the furnace generate the heat. One to another, have an each weakness and advantage. Many mining company or assay laboratory use this famous method. One from many mining company is Barrick Gold and Freeport McMoran.