Presentation on theme: "MADE TO BE MADE AGAIN CHEMISTRY FOR A CIRCULAR ECONOMY"— Presentation transcript:
1MADE TO BE MADE AGAINCHEMISTRY FOR A CIRCULAR ECONOMYMetals in a circular economy, Part 1Lesson objectives:Give reasons for the uses of aluminium, titanium and their alloys.Explain the importance of materials recovery.Discuss the limitations of aluminium recycling and how product design could be improved.
3Aluminium and titanium ExtractionAluminium and titanium exist in the earth as ores.Most aluminium exists as aluminium oxide in bauxite.Most titanium exists as titanium dioxide often in combination with other metals like iron (ilmenite).Unlike iron, they cannot be extracted from their oxides by reduction with carbon. WHY NOT?Extraction from the ores by electrolysis is expensive because:the process has many stageslarge amounts of energy are needed
4Aluminium and titanium Properties and usesLow density = light weight = softCommonly used as alloys to increase strengthCorrosion resistantA thin layer of oxide on the surface stops corrosion by H2O + O2Uses:Aluminium: aircraft, trains, overhead power cables, saucepans, cooking foil and cansTitanium: fighter aircraft, artificial hip joints and pipes in nuclear power stationCan you name another alloy?
5Aluminium and titanium AlloysAluminium commonly used as an alloy of 93% Al mixed with Si and FeHow do the iron and silicon atoms make aluminium stronger?
6Task 1: Aluminium and titanium Name of oreHow it is extractedPhysical propertiesUsesComplete the table. How much can you remember?
7Task 1: Aluminium and titanium Name of oreBauxite(aluminium oxide) (Al2O3)Rutile (TiO2) Ilmenite (FeTiO3)How it is extractedElectrolysis(many processes, uses a lot of energy)Physical propertiesSoft, low density, light, corrosion resistant (used as alloys)UsesAircraft, trains, overhead power cables, saucepans, cooking foil and cansFighter aircraft, artificial hip joints and pipes in nuclear power stations
8Task 2: The lifecycle of a can Metals like aluminium can be viewed as technical nutrients which we need to make the products we use. We need to design out waste so that the nutrients are recovered
9Task 2: The current lifecycle of a can Organise your cards around the wheel to illustrate the lifecycle of an aluminium can.
10Task 2: The current lifecycle of a can End of lifeManufactureUseRecycleExtract
11Task 3: Why recycle?Turn over your cards. Sort them into two groups to explain why recycling aluminium is better than extracting it from its ore.Recycling is a good idea but in a linear system it simply slows down the loss of valuable materials.
12Task 41) Look at the cards from the previous exercise.2) What would have to change to make aluminium recovery work better?3) Write a letter to a packaging company describing the advantages to the industry of adopting clean ‘technical’ and ‘biological’ materials flows.
13Quiz time: question 11. Bauxite is an example of…An elementA compoundAn oreA solution
14Quiz time: question 22. Aluminium is extracted by…ReductionDistillationThermal decompositionCombustion
15Quiz time: question 33. Aluminium cannot be extracted from aluminium oxide using carbon because…Aluminium is more reactive than carbonThe density of aluminium is too lowCarbon is higher in the reactivity series than aluminiumAluminium is covered in a layer of aluminium oxide
16Quiz time: question 44. Aluminium is often recycled. Which answer(s) are true and which indicate(s) that aluminium production is still essentially ‘take-make- dispose’Recycling of short cycle products (cans, packaging) is always wasteful even at high recycling rates.World aluminium production from bauxite is increasing year on year.Recycling reduces the amount of energy used to make aluminium and makes it cheaper than extracting from bauxite.Recycled aluminium is not suitable for all uses of the metal.
17HomeworkCoca-Cola is developing a bottle called PlantBottle as an alternative to aluminium cans. It is currently made from 30% plant material and the company’s aim is to make a bottle from 100% plant-based waste.Research this product on the internet. Explain why plantbottle packaging is a ‘technical nutrient’. Comment on the impact of this choice on the environment. Consider biological nutrient based packaging.