Radiochim. Acta 2017; aop Manish Mudgal*, Ramesh Kumar Chouhan, Sarika Verma, Sudhir Sitaram Amritphale, Satyabrata Das and Arvind Shrivastva Development of advanced, non-toxic, synthetic radiation shielding aggregate https://doi.org/10.1515/ract-2016-2715 Received October 17, 2016; accepted July 2, 2017 Abstract: For the first time in the world, the capability of red mud waste has been explored for the development of advanced synthetic radiation shielding aggregate. Red mud, an aluminium industry waste consists of multi com- ponent, multi elemental characteristics. In this study, red mud from two different sources have been utilized. Chemical formulation and mineralogical designing of the red mud has been done by ceramic processing using appropriate reducing agent and additives. The chemical analysis, SEM microphotographs and XRD analysis con- firms the presence of multi-component, multi shielding and multi-layered phases in both the different developed advance synthetic radiation shielding aggregate. The mechanical properties, namely aggregate impact value, aggregate crushing value and aggregate abrasion value have also been evaluated and was compared with hema- tite ore aggregate and found to be an excellent material useful for making advanced radiation shielding concrete for the construction of nuclear power plants and other radiation installations. Keywords: Red mud, aggregate, radiation, shielding. 1 Introduction The concrete possessing specific gravity higher than 2600 kg/m 3 are known as heavy weight concrete and aggregate with specific gravities higher than 3000 kg/m 3 are called heavy weight aggregate as per TS EN 206-1 (2002) [1, 2]. The shielding aggregate contains both natural occurring as well as some of the artificial aggregate. The natural aggregate includes hematite, magnetite, limonite and barite etc., which are non-replenishable and are useful for many other important applications and the artificial aggregate the use of iron shots and steel filing and even in some cases lead shots etc. [3–6]. The use of lead shots makes the material toxic in nature and therefore, there is a need to avoid the use of lead based materials for shielding applications, as it ranks second in the list of hazardous material. Apart from toxicity associated with lead, the low melting point of lead is also prohibitive as the shielding concrete should be preferably heat and fire resistance [7, 8]. Further, all the natural minerals since inherently con- tains only single shielding phase and therefore conven- tionally shielding concretes are developed by combination of various natural minerals which leads to in-homogene- ous radiation shielding matrix in the developed conven- tional radiation shielding concrete. In view of the above, there is an urgent need to develop advanced non-toxic synthetic shielding aggregate, having (a) non-toxic nature (b) capable of providing homogene- ous radiation shielding matrix (c) fire resistance and pref- erably obviating the use of toxic lead and conventional non-replenshible natural minerals resources. In the present work, for the first time in the world, a novel process for making advanced non-toxic synthetic radiation shielding aggregate by ceramic processing of red mud has been developed utilizing industrial waste namely red mud and barium containing additives. The developed advanced non-toxic synthetic shielding aggregate possessing unique characteristic features e. g. (1) non-toxic (2) fire resistance (3) containing multi-com- ponent, multi shielding and multi-layered phases and therefore capable of providing homogeneous radiation shielding matrix. The use of industrial waste red mud for making synthetic shielding aggregate obviates the use of toxic lead and conventional non-replenishable natural minerals resources. Red mud, is an aluminum industry waste and approx- imately two tons of red mud is generated for every ton of aluminum production and there are total about 85 *Corresponding author: Manish Mudgal, CSIR-Advanced Materials and Processes Research Institute, Hoshangabad Road, Bhopal (M.P.) 462064, India, Tel./Fax: +91-755-2459343, E-mail: mmudgal1969@yahoo.co.in Ramesh Kumar Chouhan, Sarika Verma, Sudhir Sitaram Amritphale and Satyabrata Das: CSIR-Advanced Materials and Processes Research Institute, Hoshangabad Road, Bhopal (M.P.) 462064, India Arvind Shrivastva: Nuclear Power Corporation of India Ltd. (NPCIL), Mumbai 400094, India Brought to you by | University of Gothenburg Authenticated Download Date | 10/10/17 8:45 AM