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Bhaduri

Arun Kumar Bhaduri, Kalpakkam IN

Patent application numberDescriptionPublished
20100247793PROCESS FOR PRODUCING BODY CENTERED CUBIC (B2) NICKEL ALUMINIDE (NIAL) COATING OF CONTROLLED THICKNESS ON NICKLE-BASED ALLOY SURFACES - Aluminizing of nickel-base alloys and a process for producing body centered cubic (B2) nickel aluminide (NiAl) coating of controlled thickness on nickel-base alloys surfaces. Importantly, the process of producing the nickel aluminide (B2 NiAl phase) coatings on nickel-base alloys is directed to achieve high hardness of 800-1100 VHN and dimensional tolerance of 80±30 microns coating thickness. The process achieves desired nickel aluminide coatings with minimum environmental emission of toxic chemicals fumes and is also environment friendly. Obtaining the nickel aluminide coating is specifically possible without the need for masking of the unwanted regions of the components and more importantly can be attended both on flat and curved surfaces thereby favouring wide scale utilities of such aluminizing process, facilitate fabrication industries required to carry out surface modifications and engineering (protective coating) on nickel-base alloys desired for high service temperatures such as nuclear industries, aircraft and gas turbine industries.09-30-2010

Arun Kumar Bhaduri, Tamil Nadu IN

Patent application numberDescriptionPublished
20100068559PENETRATION ENHANCING FLUX FORMULATION FOR TUNGSTEN INERT GAS (TIG) WELDING OF AUSTENITIC STAINLESS STEEL AND ITS APPLICATION - A Penetration Enhancing Activating Flux (PEAF) in paste form for autogenous TIG welding of austenitic stainless steels adapted for ready application with a brush on top weld surface prior to conducting autogenous TIG welding to favour single weld pass, of austenitic stainless steels of AISI 304LN and AISI 316LN varieties with weld bead penetration up to a section thickness of 12 mm. Importantly, the above (PEAF) paste based TIG welding of the invention achieves an increase in weld bead penetration of about 300% over the conventional TIG process without activating flux. The PEAF paste based TIG welding also favours higher productivity and high quality apart from being cost-effective due to less requirement of consumables and controlled heat input to arrest distortion, making it widely acceptable for variety of industrial applications for welding of austenitic stainless steel.03-18-2010

Rahul S. Bhaduri, Moraga, CA US

Patent application numberDescriptionPublished
20090133536PROCESS FOR SEPARATING AND RECOVERING BASE METALS FROM USED HYDROPROCESSING CATALYST - A method is disclosed for separating and recovering base metals from a used hydroprocessing catalyst originating from Group VIB and Group VIII metals and containing at least a Group VB metal. In one embodiment, the used catalyst is contacted with an ammonia leaching solution to dissolve and separate the Group VIB and VIII metals from the Group VB metal complex and coke associated with the used catalyst. The resulting Group VIB and VIII metal containing solution is processed through at least two additional precipitation and liquid/solid separation steps to produce, in separate processing streams, a Group VIB metal product solution (such as ammonium molybdate) and a Group VIII metal product solution (such as nickel sulfate). Additionally, two separate filtrate streams are generated from liquid-solid separation steps, which filtrate streams are combined and subjected to hydrolysis and oxidation (oxydrolysis) to generate a purified ammonium sulfate solution for further processing, such as for fertilizer.05-28-2009
20090136399Process for Recovering Base Metals from Spent Hydroprocessing Catalyst - A method for recovering metals from a spent dispersed catalyst originating from a Group VIB metal sulfide catalyst containing at least a Group VB and Group VIII metal for hydrocarbon oil hydroprocessing is disclosed. In one embodiment, the method comprises the steps of: contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the group VIB metal and the Group VIII metal into the leaching solution at sufficient temperature and pressure; forming a slurry containing at least a group VIB metal complex and at least a group VIII metal complex, ammonium sulfate and solid residue containing at least a Group VB metal complex and coke; separating and removing the solid residue containing ammonium metavanadate and coke from the pressure leach solution (PLS); precipitating from the PLS at least a portion of the Group VIB metal and at least a portion of the Group VIII metal by controlling the pH at a pre-selected pH to selectively precipitate as metal complexes the Group VIB and Group VIII metals.05-28-2009
20090136400PROCESS FOR SEPARATING AND RECOVERING BASE METALS FROM USED HYDROPROCESSING CATALYST - A method is disclosed for separating and recovering base metals from a used hydroprocessing catalyst originating from Group VIB and Group VIII metals and containing at least a Group VB metal. In one embodiment, the method comprises the steps of: contacting the used catalyst with an ammonia leaching solution under conditions sufficient to dissolve the group VIB metal and the Group VIII metal into the leaching solution; forming a leached slurry containing at least a group VIB metal complex and at least a group VIII metal complex, ammonium sulfate and a solid residue containing at least a Group VB metal complex and coke; separating and removing from the leached slurry the solid residue and coke; precipitating from the remaining solution at least a portion of the Group VIB metal complex and at least a portion of the Group VIII metal complex by controlling the pH to form a liquid material substantially free of Group VB, Group VIB and Group VIII metals and another solid material comprising substantially Group VIB and Group VIII metal complexes. Said solid material is further processed by dissolution, means of separation, further means of precipitation and oxidative dissolution to produce, separately, a Group VIB metal product solution, a Group VIII metal product solution and a purified ammonium sulfate product solution.05-28-2009
20100300250PROCESS FOR RECOVERING METALS FROM COAL LIQUEFACTION RESIDUE CONTAINING SPENT CATALYSTS - In one embodiment, this invention is directed to a method of recovering metals from a metals bearing material comprising: reducing the particle size of at least a portion of the metals bearing material; mixing the metals bearing material in an acid solution to form a first slurry containing at least alkaline earth metal compounds; separating the at least alkaline earth metal compounds from the first slurry to form a first filtrate and a metals bearing material; leaching metals from the metals bearing material to form a pressure leach solution containing transition metals; precipitating and recovering transition metals from the pressure leach solution. In another aspect, the invention relates to a method for recovering metals from a deoiled and dried coal liquefaction residue that contains spent catalyst originating from a Group VIB metal sulfide catalyst.12-02-2010
20110017636Systems and Methods for Producing a Crude Product - A process for hydroprocessing heavy oil feedstock is disclosed. The process operates in once-through mode, employing a plurality of contacting zones and at least a separation zone to convert at least a portion of the heavy oil feedstock to lower boiling hydrocarbons, forming upgraded products. The contacting zones operate under hydrocracking conditions, employing a slurry catalyst for upgrading the heavy oil feedstock. At least an additive material selected from inhibitor additives, anti-foam agents, stabilizers, metal scavengers, metal contaminant removers, metal passivators, and sacrificial materials, in an amount of less than 1 wt. % of the heavy oil feedstock, is added to at least one of the contacting zones. In one embodiment, the additive material is an anti-foam agent. In another embodiment, the additive material is a sacrificial material for trapping heavy metals in the heavy oil feed and/or deposited coke, thus prolonging the life of the slurry catalyst.01-27-2011

Patent applications by Rahul S. Bhaduri, Moraga, CA US

Rahul Shankar Bhaduri, Moraga, CA US

Patent application numberDescriptionPublished
20120039777PROCESS FOR SEPARATING AND RECOVERING METALS - A process for treating spent catalyst containing heavy metals, e.g., Group VIB metals and Group VIII metals is provided. In one embodiment after deoiling, the spent catalyst is treated with an ammonia leach solution under conditions sufficient to dissolve the group VIB metal and the Group VIII metal into the leaching solution, forming a leach slurry. After solid-liquid separation to recover a leach solution, chemical precipitation and solids repulping is carried out to obtain an effluent stream containing ammonium sulfate (Amsul), ammonium sulfamate, Group VB, Group VIB and Group VIII metals. Following sulfidation, the Group VIII metal is fully removed and Group VB and Group VI metals are partially removed from the Amsul stream. In the additional steps of oxydrolysis and iron precipitation, an effective amount of ferric ion at a pre-select pH is added to form insoluble complexes with the Group VB and Group VIB metals, which upon liquid-solid separation produces an effluent ammonium sulfate stream containing less than 10 ppm each of the Group VB and Group VIB metals.02-16-2012