Smartphone Based Colorimetric Analysis of Metallic Solutions

Abstract

Leaching metallic ores is a common method for extracting the metals that society relies on, like copper, cobalt, lithium, and many others are often extracted using leaching or in brines where the metal is a dissolved solute. In the mining and mineral processing industry, these liquids oftentimes undergo a series of treatments to become solid pure metals which are useful in many applications. During these treatments it is important to be able to measure the concentration of the target species in solution. This research proposes a new method to estimate the concentration of solution using a smartphone camera and MATLAB program to predict the concentration of the solution. It is designed to be used with common smartphones with a flash feature and uses a combination of k-means segregation and various color spaces to correlate the color of the solution to the concentration of the solution. The experiments were principally done on copper in solution (synthetic and real electrolyte) and showed that the concentrations could be estimated with an average error of less than 1.6 g/L. Further analysis of robustness indicates that the algorithm can be used with a variety of phones in different light exposure making the application widely usable for predicting the concentration of metal in solution for mining operations.