# Separation of Iron Oxide from Harbor Waste Using Selective Flocculation  
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3 Faculty of Mining and Geology, University of Belgrade, 11000 Belgrade, Serbia; [EMAIL_ADDRESS]  
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3 Faculty of Mining and Geology, University of Belgrade, 11000 Belgrade, Serbia; [EMAIL_ADDRESS]  
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The accumulation of this mixture in open-air dumps over a long period of time generates pollution in the Port of Constanta. Once the minerals are merged, they are essentially considered waste. Therefore, effective management of this waste deposit must consider both their recovery and their separation into concentrated materials that can be exploited by various economic entities [1].  
To resolve this environmental issue, a mineral processing plant was built that separates this waste into its constituents with very good results [1]. The plant processes the waste through various gravimetric methods, which will not be discussed in this article.  
Given the particularities of the waste, the processing plant recovers 95% of the useful minerals contained in it. Considering the environmentally friendly nature of the processing plant, all the process water is recycled through a thickener, from which a sludge of around 5% of all processed waste results. This sludge is currently separated on a spiral concentrator, but this separation is not very effective due to the nature of the sludge, so we had to look further to new separation methods.  
In Europe, there are at least two similar facilities for processing waste materials. In Rotterdam, the Netherlands, the bulk port operator deals with waste that is a mixture of coal and iron ore. To recover mineral compounds, they employ a technological process that involves separation in a dense medium, which is magnetite. Flotation is then used to treat the 0-0.5 mm material. This process ensures complete mineral recovery, resulting in iron ore and coal concentrates of high quality, comparable to those of transited bulk goods.  
In the port of Brussels, there are large dumps of waste resulting from accidental dumping of stored ores: coal and iron ore. Their recovery aims to recover both iron ore and coal. The iron ore contained in the waste is recovered by magnetic processes, obtaining an iron concentrate with 59.2% Fe. The remaining material undergoes a hydrocyclone operation to separate the coal from the tailings.  
For the Constanta plant, the initial testing was performed using a hydrocyclone; however, the results were inconclusive due to the mineral composition of the sludge. Although this method is still being investigated, another alternative method was thought to be suitable that could provide good results--selective flocculation.  
Selective flocculation is one of the promising methods for the utilization of fine-grained iron ores, which has been the subject of research for the last few decades in the processing of iron minerals [2; 3; 4]. The sludge used in this research consists of a mixture of iron ore and other different materials (bauxite, coal, etc.) with particle sizes lower than 0.5 mm. The sludge is not an environmental threat [5], and there is a possibility to produce a material for the industry that could be very useful in the guidelines of a circular economy. The main goal of this research is to examine the possibility of applying selective flocculation to separate iron minerals from other impurities. We wanted to test the performance of this method, and if everything works as expected, we want to implement this method in the process.