Polish version
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Hydrometallurgical recovery of materials from waste zinc-carbon and alkaline batteries

A brief description of the process

The proposed and verified on the big-laboratory scale process of hydrometallurgical recycling of zinc-carbon and zinc-manganese cells comprises a number of stages: mechanical disassembly and separation of cells, leaching, concentration and purification of solutions and obtaining products containing zinc and manganese. At the first stage intermingled primary battery waste is mechanically disassembled, allowing direct recovery of iron, constituting housing of these cells. From one ton of waste this process recovers about 220 kg of iron. Then by aerial separation is recovered polymeric plastic and paper, and remaining black mass is transferred for leaching with sulfuric acid(VI). This stage, performed at elevated temperature and under permanent stirring, results in creation of a mass containing manganese oxides and graphite and a solution of zinc and manganese sulfates. The resulting black mass is undergoes further technological processes. These processes produce material which can be used for production of new zinc-carbon cells. Obtained solutions are concentrated and separated with membrane techniques and heavy metals are separated out of them. At the last stage, with chemical and/or electrochemical methods, zinc and manganese are recovered from concentrated solutions (with 98 % efficiency). Solutions left from this process are turned back again to the process of dissolving black masses.


Advantages of the technology offered

The developed process of hydrometallurgical recycling of primary cells is characterized by:

  • recycling efficiency compliant with EU regulations, i.e. exceeding 55 %,
  • recovery of chemical compounds of zinc and manganese, directly applicable in the economy,
  • production of new electrode material for zinc-carbon cells,
  • significant reduction in mercury contents in battery waste,
  • small amount of created waste,
  • small energy consumption,
  • small consumption of the leaching reagent.


Equipment

To perform 1/4-technical scale tests there is necessary to build a recycling line consisting of leaching tanks at least 1 m3 in volume, filtration presses, a pumping system, etc.


Advancement of proceedings

Based on results of the works on the big-laboratory scale (there have been processed about 270 kg of battery waste) there have been specified parameters to perform a 1/4-technical scale test, which will allow to develop a technological documentation to construct a recycling line for zinc-carbon and alkaline cells.


Patents

Patent applications protecting the developed solution are in preparation.


Market competitiveness

EU Directive No 2006/66/EU introduced for the first time the obligation to collect zinc-carbon and alkaline cells and reach 50 % recycling rate of waste materials from them. Hence, as of 26.09.2011 there will not be allowed to use simple recycling methods e.g. Waelz process, used in Poland.

This is why it became necessary to develop an alternative method to manage this waste, allowing to recover cathode electrode material (MnO2 + carbon). It can be successfully used to produce new zinc-carbon cells. Cells produced from the recovered waste material have working parameters similar to commercially available cells. Taking into account the iron recovery level, repeated usage of MnO2/C mixture and over 95 % zinc recovery, the estimated recycling level is at least 55 %. Increase in efficiency of this process is related to i.a. repeated turning back the obtained solution to the process, allowing to reduce the amount of waste. Obtained results indicate unequivocally, that the proposed method to recycle zinc-carbon and zinc-manganese cells meets the requirements set out for EU member states.


Type of expected cooperation

Participation in implementation works, construction of a pilot installation.


Information

Zbigniew Rogulski, Ph.D.

phone: + 48 22 568 24 47