Alumina and their derivatives were researched and engineered with different formulations using advanced processes for the last 4 decades, offering a wide spectrum of applications in aerospace, automobile, energy, petrochemical, steel, defence, solar, and mining segments. Amongst various efforts to address, the challenges of optimum energy utilization, materials selection and design play a crucial role in energy-related engineering applications. Special grades of Alumina (including hydrates), as a raw material, offer numerous advantages for energy conservation and efficiency having a potential more than 12000 kt global market in 2030.

As the world shifts towards green and renewable energy, lithium-ion batteries (LiBs) play a significant role. Hindalco has developed high quality alumina and offered for very high-end applications, for example, Sub-Micron Alumina (SMA) and Ultra Fine Boehmite (UFB) are used as a separator coating on polyolefin films for Li-ion batteries to enhance performance and safety. High purity alumina ( IC : Industrial Ceramic) is used in thermal interface materials to dissipate heat faster from batteries and other electronic devices, ensuring safety and longevity. In applications like spark plugs and insulators, High Crystalline Alumina (HCA) offers electrical insulation and high-temperature stability. It's also crucial in high-voltage insulators due to its low dielectric constant and high dielectric breakdown voltage.

Additionally, Super Fine Hydrate (SFH) of trihydrates and the UFB are finding applications as catalyst support materials in petroleum refining, indirectly aiding the energy sector.

On the other hand, by effective utilization of red mud it is possible to develop sustainable and green aluminium company. Advanced R & D and fully automated process control enable the development of a wide range of calcined alumina for various applications. The cumulative impact of green alumina refining process and products contributes significantly to achieving sustainability goals.

Aluminum Tri Hydrate (ATH) is commercially produced by conventional Bayer’s Process. Apart from the main usage in the manufacturing of Calcined Alumina it is also used in multiple applications and acts as a versatile material. While surface area and particle size distribution are the two major quality control parameters for ATH in different applications, whiteness and brightness have also become critical now a days to cater the stringent requirements of different industrial applications like solid surface, artificial marbles, and cable industries. Whiteness is important as it is effectively contributing to the surface opacity, smoothness, and inking .Belagavi Alumina Refinery of Hindalco Industries Limited is the largest producers of chemical grade (specialty) hydrate and alumina in India. Mainly the ATH goes for specific applications like Flame Retardant Filler in Cables, Solid surface, and other polymeric applications, higher the whiteness and brightness, higher is the demand. The major contributing factors for the final whiteness/brightness of ATH are the different organic compounds/ impurities which are part of the process liquor. Hence one of the solutions for increasing whiteness/brightness is to arrest these colour bearing organic impurities and removing them from the liquor. To respond the needs of the customers, Belagavi Refinery and its R&D team worked in collaboration with Nalco (Ecolab) technical team on developing a solution. M/s Nalco (Ecolab) has developed a program which has got the ability to selectively remove colored organics from Bayer liquor and thereby improving the final colour properties of ATH. This product was tested at R&D center and found satisfactory. The lab test procedure was developed indigenously after multiple iterations. Based on these encouraging laboratory results a plant trial is under progress at this Refinery with required checks and controls. The expected outcome is improvement of whiteness of ATH from the current level by ~ 10 %. The same will also be reflected in the reduction in the absorbance of the liquor to the tune of 50 % at controlled dosages appx 15-20 ppm. This paper outlines the pioneer work done to develop a process to evaluate the outcomes in the whiteness and brightness in ATH.

Rho alumina is a vacuum produced phase. It is substantially amorphous, and the surface area is around 200 m2/g. Rho alumina reacts with water at room temperatures and hardens. Because of this bonding property of Rho alumina, in presence of water, this product is widely used as a replacement of cement bond in castables. Usage of alumina binder improves the high temperatures properties of the castables. It also improves the flow properties of the castable mix. Hence it is mostly preferred for the manufacture of No cement castable (NCC), Ultra Low Cement Castable (ULCC), especially where self-flow or pumpable properties are required. Since this is hygroscopic material, it absorbs moisture from atmosphere leading to the deterioration of setting property. In the present investigation an attempt has been made to determine the shelf life of the Rho alumina by evaluating the change in the basic properties of this material like LOI, SSA and XRD phases with the passage of time. An attempt has also been made to find a suitable retarder (with dosages from 0.05% to 1%) soda additive and its dosage to obtain desired setting time of this binder. Retarder additive A1 has no effect on the setting time, A2 exhibits increases is setting time at 1% level. Retarder A3 appears to be a good retarder for this system.

Panel Discussion - Specialty Hydrate & Alumina - Where next?