Metal scarcity and sustainability, analyzing the necessity to reduce the extraction of scarce metals

Bioelectrochemical metal recovery with microbial fuel cells

“…Figure 4.2 shows the produced current density with acetate and hydrogen gas as an electron donor at different hydrogen gas inflow and anolyte recirculation rates. For acetate, the maximum current density was 6.8 A/m 2 at -0.30 V anode potential, which is comparable to values reported in the literature 2,9,69 . For hydrogen gas as electron donor supplied at 3 mL/min, the maximum current density was 1.5 A/m 2 at -0.20 V anode potential, for the highest anolyte recirculation speed of 200 mL/min.…”

“…Henckens et al (2014) conclude that for 17 metals, including copper, lead, zinc and cadmium the current extraction rate is not sustainable in connection with the consumption rate in the industry 2 . Mining companies are already turning to lower grade minerals for metal extraction to provide sufficient resources.…”

“…However, as many other authors defend most of these materials are not accessible for mining purposes.To attend the global demand, which is rated around 20 million tons per year, we should find alternatives. 2,3,5 An alternative to the mining of ore is to recycle metals directly from scrap or to recover them before they are released into the environment again through remediation and production technologies. Figure 1.1 shows the possible cycles of metal processing, including the recycling and recovery of metals after use.…”

Integrated Modelling of the Global Cobalt Extraction, Supply, Price and Depletion of Extractable Resources Using the WORLD6 Model

“…All major model inputs on resources were extracted from earlier published information. Harmsen et al (2013) and Henckens et al (2014) use an estimate for the total extractable nickel resource at 1800 million ton, but we can find no scientific support for such a large estimate in the available scientific literature Mudd and Jowitt 2014). With no scientific basis in numbers, it would appear to be a wild guess.…”

Innovation in Resourcing Geological Materials as Crop Nutrients

“…In more detail, a number of studies have carried out MFA for specific commodities to assess the security of their supply as the first step in any supply chain. These studies have addressed metals (e.g., Henckens et al 2014;Graedel et al 2015), and although alternative sources and recycling are considered as ways of making better use of limited resources to maintain the stocks that society needs, there appear to be no alternatives other than reducing consumption. Industrial and construction minerals have received much less attention; quantitatively, they are dominated by sand, gravel and aggregates needed for construction, where trade is limited geographically given the cost of transport and the need for local sources for specific markets.…”