On the Sampling of Imported Copper Metallurgical Slag and Preparation of Analytical Sample

Considering the inhomogeneity of imported copper metallurgical slag in large tonnage,and the presence of some uncrushable metallic particles in the slag,a new procedure,based on the principles of statistics and probability as well as practical experience,was proposed.Every 500 tons of the slag was taken as a sampling unit,and 50-60 increments were taken from each unit.Mass of each increments was determined by its granularity.As calculated by experience,a mass of 4 kg was taken for samples having its granularity of 20-50 mm,and 2 kg was taken for sample granularity of 10-20 mm.Increments taken from each sampling unit were mixed thorougly and was called as a sub-lot,where was crushed and ground and mass-reduced as many times as required.Those uncrushable particles at specified granularity were collected into a bag and the ground sample having granularity smaller than 100 μm was also collected and were used in the analysis for their contents of copper,silver and gold.By taking the values of weighted average,contents of the 3 elements for the whole lot of slag were obtained.Two lots of slags from 2 ships were sampled by the method proposed,and the results of analysis obtained were in consistency with the results given by some laboratories abroad.