Aluminum slag is a byproduct of the aluminum industry and finding ways to use it in a sustainable manner can have significant environmental benefits.
The production of cement is a major contributor to greenhouse gas emissions, and finding alternative methods for its production can help reduce these emissions. It would be interesting to investigate how the aluminum slag can be used as a substitute for some of the raw materials typically used in cement production, such as limestone or clay.
Project Summary
Launch
Finish
Republic Of Turkey Ministry of Industry and Technology
ITouch Systems, Cukurova University Science Park
The recovery of aluminum from slag is possible through several physical and chemical processes, and its applications are abundant in various industries such as cement, ceramics, automotive, aviation, glass, refractory, grinding material production, primary aluminum, transparent armor, and ceramic cutter production. Upon cooling, the aluminum present in the slag can be recycled. Additionally, the oxide materials, including Al2O3, MgO, and SiO, present in the aluminum slag extracted from the melting furnace, are suitable for use in high-quality cement production, such as Portland Cement. A mill-drum was designed and manufactured for recycling the aluminum materials from the slag (Figure 1). The slag was first broken down into smaller pieces in the mill to minimize additional impurities from the grinding process. Aluminum billet pieces were used as grinding material in the process. The remaining powdered slag, with a lower aluminum content, was then processed using chemical methods to successfully produce Al2O3 for use in cement production.
Success in terms of the results obtained
The drum design and manufacturing, which enables the processing and recycling of slag and the recovery of aluminum material from the slag, have been completed. The registration process has been initiated and efforts are underway to start mass production of these machines for use by companies operating in this field.
With the developed machines, the recovery of almost half of the aluminum material remaining in the slag obtained from the smelting furnace has been achieved. The proportion of metallic aluminum has been reduced from 36% to 19% after the process, marking a significant success.
Chemical processes have been developed for the use of slag material, which has been processed and separated into aluminum materials in the drum mill, in cement production. As a result, the slag containing 17% metallic aluminum was enriched by washing, filtering, reduction, and neutralization reactions to obtain the raw material for aluminum, alumina, with 80% purity.
In addition to the positive factors such as increased efficiency, reduced costs and energy consumption, the slag, which was previously classified as hazardous waste, has lost its hazardous waste properties in its remaining form after the processes.
Table: Alumina values obtained as a result of chemical processes
(% mass) | H | T | A4 | A5 |
| Na2O | 3,60 | 4,23 | 25,30 | 10,00 |
| MgO | 11,30 | 9,35 | 0 | 0 |
Al2O3 | 50,30 | 54,40 | 49,50 | 79,2 |
| SiO2 | 4,40 | 4,20 | 0,90 | 1,67 |
| P2O5 | 0,18 | 0,19 | 0,12 | 0,059 |
| SO3 | 1,430 | 2,00 | 1,86 | 0,791 |
| Cl | 0,83 | 5,17 | 21,80 | 7,9 |
| K2O | 0,11 | 0,22 | 0,29 | 0,244 |
| CaO | 17,60 | 13,10 | 0,050 | 0,125 |
| TiO2 | 3,90 | 3,14 | 0 | 0 |
| Cr2O3 | 0,101 | 0,075 | 0 | 0 |
| MnO | 0,083 | 0,051 | 0 | 0 |
| Fe2O3 | 2,95 | 1,98 | 0,085 | 0,047 |
| NiO | 0,054 | 0,086 | 0 | 0 |
| CuO | 0,072 | 0,111 | 0 | 0 |
| ZnO | 0,286 | 0,218 | 0,089 | 0 |
| SrO | 0,148 | 0 | 0 | 0 |
| ZrO2 | 0 | 0,027 | 0 | 0 |
| BaO | 2,69 | 1,46 | 0 | 0 |
