As shown in Figure 1, the traditional manufacturing process for chromium compounds involves a consid-erable number of unit operations, and produces useful products of sodium dichromate (Na2Cr2O 7) and chro-mium anhydride (CrO 3), as well as several kinds of toxic residues, including aluminum-enriched residue, chromium-containing residue, and ...
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manufacturing process on the dynamic behavior of thin chromium microbeam. The analy tical models will be analyzed and corrected usin g finite element method (FEM) to de termine their
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Chromium, as trivalent (+3) chromium, is a trace element that is naturally present in many foods and available as a dietary supplement. Chromium also exists as hexavalent (+6) chromium, a toxic by-product of stainless steel and other manufacturing processes [ 1, 2 ]. This fact sheet focuses entirely on trivalent chromium.
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In this study, the influence of manufacturing process on the levels of iron (Fe), copper (Cu), chromium (Cr), nickel (Ni) and manganese (Mn) in CTC black tea were determined by inductively coupled plasma mass spectrometry (ICP-MS). It was found that the concentrations of Fe and Cu in tea leaves could greatly increase after rolling by …
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The Nickel Alloy Manufacturing Process. Alloying processes: Using Electric arc, air induction, vacuum induction melting, mechanical alloying. Rolling/Reworking: Hot working: Forging, hot rolling and extrusion. Cold working: Rolling, drawing and pilgering.
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The addition of chromium enhances the corrosion resistance and strength of the alloy, making it indispensable in the manufacturing of kitchen appliances, automotive parts, and structural components. Aerospace Industry: In the aerospace sector, where durability and resistance to harsh environmental conditions are paramount, chromium …
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INTRODUCTION. Chromium compounds are essential to many industries, but their manufacturing process is usually a major source of pollution [1-4].In the traditional manufacturing process that uses oxidation roasting …
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The current manufacturing process still faces the problem of low forming efficiency. Extreme high-speed laser metal deposition (EHLMD) is a new and efficient additive manufacturing technology that can quickly and directly shape the direct forming of difficult-to-process materials. ... The traditional process for manufacturing high …
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The SCWO process is an effective technique for simultaneously recovering chromium and for the destruction of hazardous organics in the LCD manufacturing process wastewater. Our study showed that there are two consequent reactions, chromium recovery reaction (hydrolysis) followed by the organic decomposition reaction …
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Chromite Sand Manufacturing Process. Chromite ore is predominantly used in ferrochrome production – an alloy of chrome and iron containing between 50% and 70% chromium. Steel production is the largest ferrochrome consumer, especially stainless steel production, which contains 10% and 20% ferrochrome content. The process of chromite …
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However, the high chromium superalloy has poor thermal processing performance, and the traditional process for manufacturing high chromium superalloy is complex and low productivity [19], [20], [21]. EHLMD is a new and efficient additive manufacturing technology that can quickly achieve direct forming of difficult-to-process …
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To achieve the best properties of cobalt–chromium alloys in the SLM process, the optimal parameters seem to be a laser power of 160 W, a scanning speed of 1100 mm/s, and a scan line spacing of 0.05 mm ... Additive manufacturing processes have opened new possibilities, allowing the production of complex components, …
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With the design objective of eliminating pollution at the source, this green process achieves higher resource utilization efficiency and zero emissions of chromium …
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Chrome plating is a process that involves electroplating a thin layer of chromium onto a metal object. Chrome plating has various purposes, such as improving the appearance, hardness, corrosion resistance, and friction of the object. Chrome plating can be done using two different methods: hexavalent chromium and trivalent chromium.
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Materials and Manufacturing Processes Volume 19, 2004 - Issue 1. Submit an article Journal homepage. 227 ... Views 20 CrossRef citations to date 0. Altmetric REVIEW. Nickel and Chromium-Based High Nitrogen Alloys. Hannes J. C. Speidel Swiss Academy of Materials Science, Birmenstorf, Switzerland &
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Technical emphasis in this chapter focuses on the two main variations of the electrolytic process that have traditionally produced high-purity chromium metal: the trivalent …
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Ni tool steel with high-chromium alloyed steel and to develop a forging process with heat treatment. Cr12MoV steel of the ledeburite class was proposed as a ne w material. Its chemical composition is
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In brief, the green manufacturing process of chromium compounds not only yields a higher amount of chromium but also …
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Chromite deposits are mined by both underground and surface techniques. Much of the ore is rich enough to be used directly: for production of ferrochromium, a rich, lumpy ore containing more than 46 percent Cr2O3 and … See more
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Schematic idea of the proposed green manufacturing process for chromium compounds. 46 April 2005 Environmental Progress (Vol.24, ) and oxygen (O 2) at 1200° C, the liquid-phase oxidation of chromite ore in submolten fluid more easily and quantitatively controls the reaction and separation be-
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1. Introduction. The complete range of processes undertaken in the minerals processing industry was outlined in CF 255. This combustion file gives more specific …
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Chromium compounds are essential to many industries, but their manufacturing process is usually a major source of pollution [1-4]. In the traditional manufacturing process that uses oxidation roasting at a high temperature (1200° C), water leaching and multistage evaporation crystallization [ 3, 4 ], the utilization efficiency …
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Large amounts of chromium-containing toxic solid wastes and exhaust gas are discharged, resulting in serious pollution problems. A green manufacturing process …
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The compounds of chromium are used in chrome plating, manufacturing of dyes and pigments, preservation of leather and wood etc. (Dhal et al., 2013). For most chromium compounds, sodium dichromate or chromate is the starting material, either directly or indirectly through intermediate steps, for most of the chromium compounds …
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Let the steel cool in the air for four hours. Dip the steel in a bath of hydrofluoric acid. The dip removes the buildup of mill scale caused by annealing. Mill scale is an iron oxide that peels from the surface of hot steel when it is air-cooled. Anneal and descale the steel one more time. Then heat the steel so it is molten again, at 3,000 ...
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These type of functional frameworks assembles have higher costs of manufacturing process because of the high price of both the gold electrolytic liquid and the device. ... CoM, the casting over metal method, represents an innovation in the fabrication process using cobalt–chromium alloys, combining CAD/CAM technology …
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The production process is as follows: after chromite's grinding, sodium carbonate and limestone are added (calcium roasting method) or returning slag (calcium …
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Chromium compounds are important basic chemicals essential to many industries. In the traditional process for manufacturing these compounds, the utilization efficiency of resources and energy is quite low. Large amounts of chromium-containing toxic solid wastes and exhaust gas are discharged, resulting in serious pollution …
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The refining processes for chromium metal have been thermodynamically defined by their spinel origins. The two processes of electrolytic deposition, discussed in the previous …
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chromium is a major problem when it comes to environmental pollution prevention efforts and worker safety. Hexavalent chromium, in the aqueous liquid and misting forms, is a known ... manufacturing process. After the barrel has been plated it must be exposed to a hydrogen bake-out process. During this process, the barrel is heated so that ...
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Hard chrome plating is an electroplating process in which chromium is deposited from a chromic acid solution. Thickness of hard chrome plating ranges from 2 to 250µm. Various types of hard chrome include micro-cracked chromium, micro-porous chromium, porous chromium and crack free chromium. It is essential that the micro …
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Chromium compounds are important basic chemicals essential to many industries. In the traditional process for manufacturing these compounds, the utilization efficiency of resources and energy is ...
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Fiber Lasers. The fiber laser was invented by Elias Snitzer in 1963. Within laser material processing, the fiber laser is regarded as the new solid-state laser technology and is extensively used in many industrial applications. The base wavelength generated by a fiber laser ranges typically from 1,060 to 1,085 nm.
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The effectiveness of supercritical water oxidation (SCWO) process for the simultaneous recovery of chromium and destruction of organics from liquid crystal display (LCD) manufacturing process wastewater was investigated. The experiments were performed in an isothermal continuous-flow tubular reactor and H 2 O 2 was used as an …
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