Technology options for Recycling of Electrolytic Nickel Solutions
In Chapter III, various latest methods like Electrolytic Recovery, Ion Exchange, chemical Precipitation, Hydrometallurgy, Evaporative Recovery, Reverse Osmosis, etc., have been discussed and briefly explained as these processes have reached a stage of commercial exploitation for such applications, by concerns in developed countries. These methods are likely to have possibilities of adoption in India, depending upon the quality and quantity of sludge and solutions available for recycling. The emphasis in this Chapter is on technologies of recycling as it amounts to reduction of Nickel consumption. In developed countries recycling is very important as the process water is expensive and several electroplaters do not draw fresh water from public system regularly, but recycle the solution. In India, the fresh water is inexpensive, but certainly all plating chemicals are expensive and it is worthwhile to recycle maximum possible solution to reduce consumption of plating salts and chemicals.
Technology options of Recovery of Metallic Nickel
In Chapter IV, methods of recovery of Nickel from solutions with medium and low concentrations have been discussed. Use of Ion Exchangers, Chemical Precipitation, Electro dialysis have been explained. As none of these methods, have been operated on prototype scale or experimental scale, in India and therefore exact economics of recovery could not be ascertained., as a prelude to the recovery process all solutions/ sludge have to be concentrated. The Ion exchange method is one of the methods being adopted for concentrating dilute solutions. The key factor for prototype and small scale exploitation of this technology would depend on the willingness on the part of large electroplaters to sell Nickel containing sludge ad solutions at reasonable cost of processors and subsequently assure them of supplying this material at the agreed cost without any interruption. The processors may be willing to make investment only if such kind of assured supply is available as they would not be able to source their raw material from any other sources.
Landmarks of Technological Developments in India
It is very well accepted globally, that Indian entrepreneurs are genius and they would not leave any stone unturned where some worthwhile can be recovered from the wastes. Obviously, through available technologies and possible resources, our concerns are not consciously allowing any significant waste of Nickel or Nickel containing solutions.
In Chapter V, we have mentioned about the work done by various institutions and concerns in India, in this direction. Most of the work has been done by new entrepreneurs and research institutions related to this subject. Not much work has been done by industry, as the large ones feel it as an infructuous effort and the Nickel containing salts. Considering the national importance, for conservation of foreign exchange and global concern for waste recycling, the technology development is fairly of paramount importance. In Indian scenario, the recommendations for reducing Nickel consumption is by adopting improved technologies of electroplating and electroforming, adequate training of operating personnel, availability of process literature and making available simple compact units of recycling Nickel containing solutions and recovery of Nickel.
Once this kind of technology is developed, it will have spin-offs in other sectors of industry where metals can be recovered and solutions can be recycled. A futuristic project, in this area could be, recovery of Nickel from electroplated parts, abandoned by users, metal scraps, process rejects etc. if stripping technology is developed, we may be able to recover Rs. 40 to 50 crores worth Nickel annually from scrap. Back
