FEB 11 - MAY 9 2021   
Grey Matter – New Materials for the Post-Fossil Era, CentroCentro, Madrid

MAY 23 2020 - AUG 8 2021
Critical Zones – Observatories for Earthly Politics, Center for Art and Media, Karlsruhe

APR 9 - SEPT 12 2021   
Colors Etc, Le Tripostal, Lille

Studio ThusThat designs and makes with uncommon materials.
Right now we are exploring industrial wastes from mining and metallurgy.


Bauxite Residue

Bauxite Residue, a.k.a. Red Mud, is a byproduct residue of the alumina industry. More than two parts of red mud are produced for every part of aluminum. This means that over 150 million tonnes are produced each year, and left unused in giant pits. This project questions our notion of ‘waste’, and shows the value of secondary materials in a world of finite resources. Working with factories and research labs, the industrial residue is transformed into ceramic bodies and glazes. 

Studio ThusThat: Red Mud on Vimeo.


This is Copper

Copper is ubiquitous to our modern world, yet it is largely invisible. It is the oldest metal mined by humankind, with ancient uses dating back 8000 years. The metal was historically used for its malleability and antimicrobial properties (indeed, even against viruses ). Today, it is crucial for a renewable future: a wind turbine alone can contain up to five tonnes of copper, and ten tonnes of the metal are needed per kilometre of high-speed railway.

But what exactly is copper? The metal we know is only part of a much wider material story. Mining overburden, tailings, metal concentrates, rare metals like gold and silver, sulfuric acid, sulphate solution, slag, and more. 

All of this is copper, or in other words is a direct result of processing, using, and recycling copper. This project exposes and proposes potential uses for these overlooked byproducts as we continue to search for new ore streams.

Slag is the leftover impurities of the smelting process. During the pyrometallurgical purification process, slag is extracted and poured out in molten form, cooling into a black glassy stone — like man-made lava.

In this project, slag is used as a geopolymer. 

Geopolymerisation is a technology that uses common inorganic compounds to create high-performance alternatives to standard cement. Because the slag has already gone through the high-temperature smelting process, it is reactive and ready to be used as a binder. It thus replaces the need for cement etirely. Additionally, coarser forms of slag can be used as aggregate in the place of sand. The result is a very strong black concrete-like body made from slag, with about 77% lower CO2  footprint than standard cement.

The project was realised in close collaboration with  KU Leuven and Metallo Group, Belgium. 


Amphirol is a screw-like vehile used to farm bauxite residue. As the amphirol travels, it compresses the residue and creates tracks. These furrows allow the water, which has been squeezed from the residue, to drain into the perimeter channel .

Copper Anodes are composed primarily of copper metal and copper oxides (> 80%) but can still containing other residual metals. Anodes are used as source of copper in the electroforming process. 

The Bayer Process, developed by Carl Josef Bayer, is a method for producing alumina from bauxite ore.

Concrete, when made from geopolymer binder instead of Portland Cement, produces up to 77% less CO2 emissions.

Electroforming, in both hydro- and pyrometallurgy, is the last step in the process of refining copper. In electrowinning as in electrolysis, CU2+ ions in a dissolved copper sulfate solution are attracted to the negative charge at the cathode, and form directly to the surface with up to 99.99% purity.

Gardanne, a town in the Provence region of France, is the site of the first factory to ever produce red mud. The factory opened in 1894, five years after the patent for red mud was filed.

Geopolymer is an alternative cementitious material synthesized by combining source materials that are rich in silica and alumina such as fly ash (FA), ground granulated blast furnace slags (GGBFS) with strong alkali solutions.

A cathode – a 50 to 80 kg copper square – is produced when pure copper separates from unwrought copper in an electrolytic refining process. The resulting cathode has a purity greater than 99.95%. 

A Mill breaks material into smaller parts. In processing copper slag two types of mill are most common: the SAG mill, and the ball mill.

Overburden refers to the material between the ground surface and the material to be mined. It is different from tailings (see tailings), in that is has not been processed, and is therefore not contaminated with toxic elements. Overburden is used as a construction aggregate for buildings and roads, as well as for contouring land or in place of soil.

Each recycling facility usually specializes in a specified form of copper recycling, be it the coils from refrigerators, car radiators, e-waste, etc. Due to the particularized method of mechanically “mining” this urban copper ore stream. This “Secondary copper concentrate” is then returned back into the production cycle at pyrometallurgy and continues in much a similar way than the raw mined ore. In this secondary cycle, slag is also produced, up to 3X per unit copper produced.

Slag is a by-product obtained during the separation of a given metal from its raw ore source. Slag from copper is particularly interesting given it’s wide array of possible uses: the material can be used as an abrasive material, in road construction, and as ballast. Despite the increasing rate of copper slag reuse, a huge amount of  annual copper slag production is disposed in dumps or stockpiles to date. One of the greatest potential applications for reusing copper slag is in cement and concrete production.

Tailings are the materials left behind after the chemical and mechanical refining of raw ore. Through this process the valuable material (concentrate) is separated from the non-valuable material, or tailings. This left-over matter has been contaminated with various acids and leachates. 

Bauxite tailings, more commonly referred to as red mud, is the waste substance which is created during the production of aluminum oxide. Industry experts believe that more than 150 billion tons of the substance is produced each year. Management of this huge amount of waste is one of the biggest challenges facing the aluminum industry.