using hydrogen sulphide to produce a highgrade sulphide containing at least 50 nick el This mix ed sulphide is then pressure leached to give a high purity concentrated nick elco balt solution suitable for solvent e xtraction to separate the valuable metals The Mond or Carbonyl Process is a method to treat nick el o xide sinter In this process the nick el o xide sinter is treated with hydrogen and fed into a volatilization kiln Here it meets carbon mono xide at about 60C to form nick el carbonyl gas The nick el carbonyl gas decomposes on the surface of preheated nick el pellets that fow through a heat chamber until they reach the desired size A t higher temperatures this process can be used to form nick el powder 144 The use of electrical cells equipped with inert cathodes is the most common technology for nick el refning Electrowinning in which nick el is removed from solution in cells equipped with inert anodes is the more common refning process Sulfuric acid solutions or less commonly chloride electrolytes are used 145 With regard to secondary production nick el scrap can be used in melting processes as addition to refned nick el Moreover efcient recycling of nick el tak es place in the stain lesssteel industry which is the major frst use of nick el In 2010 around 43 of all nick el used in EU came mainly from stainless steel scrap process scrap end of life products 146 Some nick el mining activities in Europe tak e place in Finland smelting and refning in Finland France Norway and the UK where nick el mine products and intermediates mainly from outside the EU are converted into nick el metal Nick el production in Europe is diverse with production in Norway and Finland being very electrointensive Sites in France and the UK are much smaller and less electrointensive The conversion of nick el into frstuse prod ucts e g stainless steel nick el alloys foundries plating andend use products e g tubes and pipes metal goods electrical and electronic equipment tak es place in other industries Most of the nick el produced in Europe is high purity nick el class I nick el content 99 Other nick el products such as ferronick el and nick el pig iron are mostly produced outside of Europe with most nick el pig iron being produced in China Ferronick el and nick el pig iron have a lower nick el content ranging from 415 nick el pig iron to 30 ferronick el The specifc GHG emissions difer signifcantly with class I nick el production at 7 8 k g CO 2 k g nick el 328 k g CO 2 k g nick el in ferro nick el and between 70 k g and 98 CO 2 k g nick el in blast furnace and electric arc furnace nick el pig iron production respectively 147 Nick el refning is highly electrointensive at 555 MWht nick el product But also processes 144 Bell 2019 145 W orld Bank 1998 146 Nick el Institute 2012 147 Nick el Institute 6 plants with a pyrometallurgical Imperial Smelting Furnace ISF technology 14 plants with R oastingL eachingElectrolysis process RLE full hydro 2 plants with RLE process combined hydro and pyro processes A fter 2000 a number of plants were closed down mainly smelters using the ISF technology The major reason for the closure of plants using the ISF technology was their comparatively higher energy consumption leading to much higher production costs The ten zinc refneries which closed used to produce up to 740 kt zinc metal per year More than half of that pro duction loss has been compensated by production increases in the remaining RLE plants 140 In 2015 there was 1 ISF plant left in the EU providing only 3 of the EU production 141 down from 18 in 2004 Presently most zinc 142 is produced using the RLE full hydro process accounting for 93 of the total production The RLE full hydro process has the lowest energy consumption and 94 of the consumed energy is electricity with 84 of electric ity consumed used in the electrolysis stage of the zinc refning process T oday electricity represents 85 of all energy used in the production of zinc 143 Further emission reductions in zinc production will not be straightforward given that second ary raw materials in smelter feeds are increasing which can lead to higher CO 2 emissions 55 Nick el Nick el is primarily e xtracted from nick el sulphide ores which contain about 135 nick el content and the ironcontaining lateritic ores limonite and garnierite which contain about 12 nick el content Sulphide ores can be separated using froth fotation and pyrometallurgical processes to create nick el matte and nick el o xide These intermediate products which usually contain 4070 nick el are then further processed often using the SherrittGordon Process L ateritic ores are usually treated with hydrometallurgical processes L ateritic ores also have a high moisture content 3540 that requires drying in a rotary kiln furnace High pressure acid leaching HP AL is one of the most common treatment processes of lateritic nick el ores The high temperature around 250C acid pressure leaching of nick eliferous laterite ore has been commercially in use since the 1950 s The acid pressure leach solution is treated 140 International Zinc Association 2012 141 This last ISF plant has a process that enables to process feedstock which cannot be treated by regular zinc smelte rs such as mix ed zinclead mineral concentrates with elevated Pb content and comple x waste streams Since there is worldwide little processing capacity for these materials there is a bigger margin to operate the process 142 In 2010 zinc production was 2098 kt and this production was achieved in 12 plants 1 plant with ISF technology 10 plants with RLE process full hydro 1 plant with RLE process combined hydro and pyro 143 International Zinc Association MET ALS IN A CLIMA TE NEUTRAL EUROPE A 2050 BL UEPRINT 47