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“Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA) shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.

Lateritic bauxite are the products of intense subareal weathering of rocks. It is characterised by a particular enrichment of aluminium-hydroxide minerals such as gibbsite, boehmite and diaspore. Based on geological occurrences, bauxite is classified as lateritic, karstic, tikhvin type and about 86% deposits of the world are lateritic bauxite deposits. They typically are in stable areas of plateaux, where they had sufficient geological time to form and were protected from erosion. India is endowed about 3896 million tons of bauxite resources and Maharashtra state constitutes about 5 % of the total assets. The medium to high grade lateritic bauxite occurrences are located in western Maharashtra which spread up in two distinct belts, viz. high level and low-level coastal areas. The coastal bauxite deposits in Raigad, Ratnagiri and Sindhudurg districts are located at altitude varying between 50 to 350 m above mean sea level (msl), while high level bauxite deposits of Kolhapur, Satara and Sangli districts occur on the plateaus with an elevation 900 to 1300 m above msl. Most of the laterite of the western Maharashtra overlies the Deccan Trap basalt, except in some part of coastal areas, it either caps the Kaladgi sandstone or overlie the Dharwar pebble beds. The lateritic bauxite deposits of the western Maharashtra have been studied with reference to its geology, chemico-mineralogy and petrological characteristics. Field studies indicate the following successive stages developed during in-situ weathering: Deccan trap basalt (parent rock) → weathered basalt → saprolite/lithomargic clay → bauxite → duricrust (ferruginous, aluminous laterites). The geological, physical and chemico-mineralogical characteristics of the bauxite and laterite located in two belts is distinguished from one another. For the present study, two bauxite deposits namely Ringewadi and Velas located in Kolhapur (high-level) and Raigad (coastal) district of western Maharashtra respectively have been selected. The representative samples of bauxite, laterite, saprolite, parent rock have been collected. In present paper, comparative study has been done and the geological, geomorphological, geochemical, mineralogical, petrographic and physical characteristics of low level (coastal) and high-level lateritic bauxite deposits are highlighted.

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Corrosion is a natural occurring phenomenon which exists as a part of our everyday life. Generally stainless steel is having good corrosion resistance which undergo some specific type of corrosion. Corrosion problem in stainless steel has a huge economic and environmental impact on virtually all facts of world’s infrastructure, from highways, bridges, and buildings to oil and gas, chemical processing, and finally it play an ever increasing role in the largest industry in the world is food industry and automotive industry. The corrosion problem is quite costly and it has no easy solution so large amount of money is utilized to analyse the corrosion damage and also to replace the corroded components. The focus of this paper is to investigate the intergranular corrosion studies of industrially important stainless steel of AISI 430 by two different corrosive solutions were 40% Nitric acid (ASTM-A262-Practice C) and copper – copper sulphate 50% Sulphuric acid (ASTM-A262-Practice E) of Gas tungsten Arc welded Metal which were weighted and immersed in test solutions. After immersion, these weldments were removed, washed, and then weighted to determine the weight loss. The analysis of experimental data obtained on intergranular corrosion and the micrographs by Scanning Electron microscope were carefully analysed, monitored, and revealed to study the behaviour of intergranular corrosion of AISI 430, Stainless steel weldments.