Comparison of the effectiveness of different types of extractants for recovery of iron from mineral wool waste

The paper presents the results of iron extraction from wool waste. In studies as extractant was used: water, EDTA, acetic acid, formic acid, DTPA, ammonium lactate and calcium lactate. For analysis has been taken wool after one year cultivation of tomato and cucumber and wool after two years of mixed cultivation. The main aim of the analysis was to determine which extractant allows the greatest recovery of the iron from waste mineral wool. Current trends in the agriculture development and the fertilizer industry are aimed at maximizing the recovery of nutrients from waste for re-use. Demonstration of the effectiveness of the recycling of valuable trace elements contained in the mineral wool can make develop a method of wool utilization profitable. In addition, the high cost of fertilizer components makes a new type of medium containing nutrients obtained by extraction from mineral wool waste, can be an interesting option in the future. Implementation of this type of process is consistent with the objectives of Sustainable Development, as well as the environmental policy of the European Union. The proposed way to get iron from mineral waste wool consists of following steps: drying at 30 C for 24 hours, grinding to particles with a sieve size of 0.40 nm, extraction and phase separation. The studies included the effect of time, temperature and type of extractants on the efficiency of the process. The iron content in the samples was determined by spectrophotometric method based on the ferric ion complex of 2,2-pyridyl in a solution at pH of 3.1.