Ensuring sustainable industrialisation, infrastructure and innovation
The Sustainable Development Goals commit countries to the environmentally sound management of chemicals and all wastes throughout their life cycle by 2020 to minimize adverse impacts on human health and the environment.
Sustainable industrialisation through tech
A sustainable industrial future requires innovative solutions which enable the de-coupling of economic growth from material consumption. This requires technologies for efficient production and the lean management of resources – as well as the re-use, recovery and recycling of waste. Metals and minerals are indispensable in the manufacture and functioning of all of these technologies.
3D printing (3DP) enables flexible, efficient, sustainable manufacturing – adding materials one layer at a time, with near zero waste. It also enables swifter response to demand and more localised manufacturing, relies on a simple supply chain, and requires fewer raw materials than traditional manufacturing methods. 3DP also makes it possible to produce single parts, which may be easily combined together or disassembled in order to be repaired, replaced or upgraded. This supports the circular economy transition, as if any damage occurs to a product, it does not have to be landfilled as waste. It is estimated that additive printing could reduce manufacturing costs by USD 170 to 593 billion, energy use by 2.54 to 9.30 exajoules (EJ) and CO2 emissions by 130.5 to 525.5 metric tonnes by 2025. 3D printers are built from a variety of metals and minerals, including aluminium, iron, copper, nickel, chromium, tin, zinc, bauxite and sulphur.
A waste autoclave is a chamber in which pressurised steam is used to decontaminate waste. They are used in nearly every industrial sector, including aerospace, composites manufacturing, or metal heat treating. The state-of-the-art autoclave chambers are manufactured using stainless steel, or nickel-clad. Once waste is put inside the autoclave and the chamber is closed, all air is removed, by a vacuum pump or by pumping in steam. In the next step, high pressured steam is injected into the chamber to raise the internal temperature, a timer is started and the process begins. After sterilisation, during which microorganisms are killed, the autoclave chamber is exhausted of pressure and steam, so that it can be safely opened for cooling and drying. Waste can then be taken out and circulated back into the economy as a resource.
Materials recovery facilities (MRFs) – also known as materials recycling facilities – play an important role in recovering, re-using and recycling raw materials. Waste delivered to the facility is sorted into different types of materials, including plastics, cardboard, paper, or metal. MRFs include a tipping floor, a drum feeder, units for separation operations, storage areas and transporting equipment.
Incoming material is dumped onto a tipping floor, usually made of concrete or a combination of recycled iron shavings and concrete. Concrete is made of air, water, cements (made of calcium, silicon, aluminium, iron and other ingredients), supplementary cementing materials (e.g. fly ash, slag cement, silica fume), aggregates (e.g. sand, gravel, crushed stone) and chemical admixtures. Waste is then dropped into a large steel bin (known as a drum feeder). In the next step, cardboard is removed by a screen using rotating shafts with discs (usually made of stainless steel, aluminium, or brass). Non-fibre elements are sorted using automated optical processes with the use of cameras and lasers, while a magnet (produced from an alloy of various metals, including iron, nickel, zinc, cobalt, and others) removes steel cans, and an eddy current separator (including rare earth magnets) removes the aluminium cans and non-ferrous metals. Glass bottles are shattered by steel discs, while plastics are separated by an optical or manual sorter.
Composting is another way to manage waste. Industrial composting methods include aerated static pile composting, high fibre composting, in-vessel composting, mechanical biological treatment and windrow composting. In general, composting means a biological decomposition of organic matter by fungi, bacteria, insects, worms and other organisms. It is a relatively quick, safe, clean and natural process. Composted output can be used in many different ways, including agriculture, brownfield sites or even energy generation. Some composting methods, such as in-vessel composting, rely on equipment which could not be built without metals and minerals. In-vessel composting uses an environment-controlled enclosed environment – like a drum, silo, container or concrete-lined trench – into which organic materials are fed prior to turning or mixing. The size of the vessel can vary in size and capacity, but is built mainly of steel and aluminium.