CEReS -Co-processing of Coal Mine & Electronic Wastes: Novel Resources for a Sustainable Future

International audienceMany coal mines produce waste which causes acid mine drainage (AMD) potentially resulting in severe environmental damage. This drainage can be treated, but most wastes will continue to produce such drainage for hundreds of years. Therefore, longer term, permanent solutions are needed. At the same time, the pace of technological development means most electrical and electronic equipment becomes obsolete within a matter of years. This results in the generation of vast and growing quantities of electronic waste (e-waste) every year. Where this cannot be recycled, it must be discarded. CEReS was a 3.2 M€ RFCS-funded project comprising eight partners from five countries. It targeted the development of a co-processing approach to treat these waste streams to produce metals and other valuable products, while eliminating their environmental impact. This brings together two waste streams from opposite ends of the supply chain (for which no alternative treatment option exists); turning each into a novel resource in a single, coherent 'grave-to-cradle' process. This industrial ecology approach is key to supporting a circular economy while securing the sustainable supply of critical raw materials. The project successfully elaborated a novel co-processing flow-sheet comprising: (i) the accelerated weathering of AMD-generating coal production wastes to generate a biolixiviant; (ii) the pyrolysis and catalytic cracking of low-grade PCBs to produce hydrocarbon fuel, a halogen brine a Cu-rich char; (iii) the leaching of base metals from the char using the biolixiviant; (iv) the reuse of the stabilised coal wastes; and (v) the recovery of valuable metal while concentrating precious and critical metals into enriched substrates. These individual process units were demonstrated individually at lab-pilot scale. The data were then used to validate the entire flow-sheet in an integrated process simulator. Finally an LCA approach was used to demonstrate the environmental benefits of the CEReS process over the status quo

Mineralogical characteristics of copper flotation products from Cayeli mine, Turkey and their influence to mineral processing

peer reviewedThe paper presents mineralogical characteristics and pecularities of minerals distribution in products from Cu cycle of clastic ore mineral processing in Cayeli concentrator, Turkey. Special attention has been drawn to the mineralogical pecularities of sphalerite. The study has covered 16 samples from Cu flotation feed, Cu rougher concentrate, Cu final concentrate and tailing, each sieved in 4 granulometric classes. Significant quantity of sphalerite charactarized by higher amount of Cu and Fe as isomorphic impurities or extemely fine crystals of chalcopyrite are present in the Cu concentrate. Based on the performed studies, an improvement in the processing circuit has been suggested - especially in the grinding and hydrocycloning circuits

Separation by ultrasonic degassing of flotation pulps

peer reviewedAn ultrasonic impact on a gas saturated flotation pulps has been investigated with the aim to generate bubbles in alternative to the classical way - i.e. instantly onto the surface of the mineral particles. A mciro flotation cell and pure minerals have been used for this purpose. Faster kinetics and reduced reagent consumption could be pointed out as main advantage of the studied approach

Vibro assisted cementation of gold onto zinc granules

peer reviewedCementation of gold aqueous complexes onto zinc granules instead of zinc dust was studied in a column subjected to vibrations. Two type of lab csale cementing reactors were tested and their efficiency compared a column and a bed-type one. The influence of foreign ions addition upon the degree of gold cementation was investigated as well

Application of zeolite minerals as an in-situ amendments for heavy metals polluted soils

peer reviewedMetal fixation from simulated rain water onto zeolite adsorbents has been studies using a column filtration mode. Further on, soil artificially contaminated with heavy metals have been brought into contact with the zeolites. The loaded adsorbents have been studied via IR spectroscopy wih the aim to reveal the predominant mechanism of metal uptake

On the influence of the disturbed conditions in the centrifugal concentration of heavy fine particles

peer reviewedModel investigations were carried out with the aim to improve the method for accelerated gravity separation of heavy fine mineral particles. The effects of feed particle size has been studied with the aim to generate disturbed conditions inside the riffle zones of a bowl-type centrifuge and thus to avoid material packing leading to better separation conditions

Coal-gold agglomeration of alluvial gold

peer reviewedThe study concerns feasibility testing of the coal-gold agglomeration process as alternative to the amalgamation for upgrading of alluvial gold fractions found in a dredge line. Different process parameters such as oild and coal type, coal/oil and agglomerates/gold ratio have been varied with the aim to optimise the degree of gold recovery. The addition of quartz and heavy mineral particles in the slury in view outlining process selectivity is also discussed

Clean Coal Technologies and Carbon Capture and Storage in Kazakhstan – Reflections and ACCESS project results

ACCES