Recovery of Gold from Waste Solutions

 

For a long time the recovery of gold from waste solutions residues has been practiced and studied by metallurgists. The quantity of soluble gold, silver and platinum present in some of the solutions resulting from the manufacture of jewellery, silver plate and personal adorn is significant and these precious metals are very valuable. For this reason it is very important that all operations in which they are employed must be performed with great care, as regards unnecessary wastage resulting from the different modes of operation and that all the solutions must be stored and used for the recovery of gold and platinum group metals. Basically, the recovery of the gold and silver from goldsmiths, jewelers and silversmiths waste solutions such as coloring liquids and their rinsing waters; the poor electrolytic solutions and their rinsing waters; the stripping and dipping mixtures of different types; the pickling liquids; the solutions used for washing out the polished and finished work; the wash-hands water and all other liquids likely to contain gold, silver and platinum group metals are important sources.

In order to find out the optimum method for recovering gold, silver and platinum in the most efficient and economical way, it is important to perform some experiments or tests so that the procedure will be employed with minimum variance or change, without any doubt, the information will be of great value and any investment will be recovered in the short time. International prices of precious metals have obliged to develop new procedures or improve the classic procedures due to development of gold projects of simple treatment will disappear soon.

It is well known the recovery of silver from hyposulphite and toning solutions, and the swilling waters of photographers, as well as the liquid residues of glass mirror manufacturers. The best recovery methods have been focused for the extraction of the precious metals and there are no satisfactory information for the guidance of the beginner and the more practical and experienced operator may not be able to explain with total clarity the most simple and successful methods. The chemical coursed at the university or institutes render an invaluable service to those of the new generation, but they cannot give all that is required for performing tests on waste solutions because the experiments using synthetic solutions of gold and silver are the base case. In other words these substances have no contaminants, which are results of the manufacturing process.

Without any doubt, it is important to use part of the time in labor, and by laying bare some of the economies to be obtained by following a particular method. Some time ago, low attention was paid to the recovery of gold and silver from barren solutions. In some cases, it was common to consider a simple container as final receptacle for all these solutions, which after running through a piece of coarse bagging were discarded. Nowadays, the idea has change and the process consider environmental issues, metal prices and the economy of the process to be adopted for the recovery of the gold and silver present.